Curarisation compared with other methods of securing relaxation in anaesthesia

We begin 2021, the year of our 75th anniversary, with a special commentary on our first ever original article, which was published in 1946 and was all about initial experiences with curare. This is the first in a new limited monthly series of articles we have called ‘Contemporary Classics’, and each looks at a popular paper from a subsequent decade. This month’s offering reminds us of three important areas for future research: studying the effects of deep intra‐operative neuromuscular blockade on patient‐centred outcomes; the implementation of quantitative neuromuscular blocking monitoring into widespread clinical practice; and the need for an ideal neuromuscular blocking drug that can be readily switched on and off. Next month, we tackle the subject of deaths associated with anaesthesia, and the index paper from the 1950s shows just how far clinical governance and audit have come in 60 or so years. We hope you enjoy these articles and all that the Association of Anaesthetists have planned to celebrate the occasion throughout the year.

Resternotomy following cardiac surgery has always been suspected to be associated with poor outcomes, and this new national audit from Agarwal et al. seems to confirm these suspicions. They were able to pool data from 23 UK centres and found that the mortality in these patients was 15%, with ~90% requiring transfusion of red cells and ~23% requiring renal replacement therapy (Fig. 1). Kendall and O’Keeffe list strategies that may one day enable us to eradicate resternotomy from clinical practice, and provide a discussion of the associated historical context. In October 2020, the PREVENTT trial of pre-operative intravenous iron to treat anaemia before major abdominal surgery was published in The LancetA summary of the methods, results and clinical implications is provided this month by Lachlan Miles, who suggests we should now all re-evaluate our practice but also that the story of intravenous iron in the pre-operative period is by no means over. In their editorial, Sharma et al. discuss the role of routine postoperative troponin measurement in the diagnosis and management of myocardial injury after non-cardiac surgery. They argue there should now be a shift to the use of pre-operative biochemical marker measurements instead of tools such as the modified revised cardiac risk index to risk stratify patients before surgery. 

Figure 1 Time from arrival in ICU to resternotomy in those who did and did not require renal replacement therapy. The (median (IQR [range]) of those who required renal replacement therapy 960 (293–3805 [5–44,640]) min vs. those who did not 420 (180–1046 [0–60,500]) min. *, p < 0.001.

Last year, Khan et al. published their secondary analysis showing that fluid optimisation before induction of general anaesthesia did not significantly affect the occurrence or degree of haemodynamic instability during induction. This month, Wong and Irwin discuss the implications, including the limitations of the study by Khan et al., and conclude it is not possible to determine from the available data whether modest fluid administration, presumably to compensate for fasting, can indisputably prevent post‐induction hypotension. Do you agree? Send us a letter and there is a good chance we will publish it! There is reasonable evidence to suggest there is an increase in positive airway pressure in spontaneously breathing patients receiving high-flow nasal oxygen, but what about when it is used for apnoeic oxygenation? This new randomised controlled trial from Riva et al.finds that high flow nasal oxygen generates positive airway pressures during apnoea when the mouth is closed. The airway pressures depend on flow rate, but remained < 10 cmH2O despite flow rates of up to 80 l.min−1. They conclude that maintenance of high oxygen concentration appears to be of greater importance than flow rate and airway pressure (Fig. 2).

Figure 2 Fitted mean trajectories of airway pressure with 95%CIs for combined closed and open mouth based on linear mixed models with different assumptions for the effect of flow rate (as indicated right).

The environmental impact of our work has been in the spotlight again recently, and this new cohort study from Zucco et al. suggests that desflurane is not associated with reduced risk of postoperative respiratory complications as compared with sevoflurane. This new piece of evidence might help organisations make decisions about the use of desflurane in their operating theatres. A more surprising result was reported in this randomised controlled trial from Albrecht et al. on the impact of short-acting vs. standard anaesthetic agents on obstructive sleep apnoea. They found that agents such as desflurane and remifentanil did not reduce obstructive sleep apnoea on postoperative nights one and three compared with standard agents (Fig. 3).

Figure 3 Change in the apnoea‐hypopnoea index (AHI) in the supine position over time (values are shown as mean with 95%CI). PreOP, pre‐operative; PON1, postoperative night 1; PON3, postoperative night 3. Blue line, standard agents; red line, short‐acting agents

An accurate, non‐invasive and economical method of pre‐operative anaemia screening would help with early diagnosis and hence expedite further investigations into its aetiology. This new study by Ke et al. finds that the Rad‐67 Rainbow was found to be inadequate for estimating actual haemoglobin levels and insensitive for detecting pre‐operative anaemia. Elsewhere, we have: a review of fit testing N95, FFP2 and FFP3 masksa review of apnoeic oxygenation in paediatric anaesthesiaa randomised controlled trial of trimodal prehabilitation in patients undergoing colorectal surgerya comparison of cardiopulmonary exercise testing in severe osteoarthritis; and a population based study of gestational anaemia and severe acute maternal morbidity. Finally, will this new systematic review, meta-analysis and trial sequential analysis by Desai et al. finally settle the question of epidural vs. transversus abdominis plane (TAP) block for abdominal surgery? They find that epidural analgesia was statistically superior to TAP block in the postoperative pain score at rest at 12 h and the need for intravenous morphine‐equivalent consumption at the 0–24 h interval, but these differences were not clinically important. They suggest clinicians should balance the risks against the benefits for individual patients and decide on that basis.

We hope you enjoyed our first live broadcast all about a new paper on COVID-19 vaccines by Professor Sir Jeremy Farrar and Professor Tim Cook, which has now been viewed > 10k times! We are planning a special live Twitter broadcast on the 11th of January to launch our new 2020 regional anaesthesia supplement with our editors, authors and you! Chairing the sessions will be Kariem El-Boghdadly, Ed Mariano, Ki Jinn Chin and Laura Duggan.

See you there!

Mike Charlesworth and Andrew Klein

Principles for guidelines and guidelines for principles

This month, we are delighted to publish the concept and methods for the Project for Universal Management of Airways (PUMA) (Fig. 1). This extraordinary project aims to develop a single set of airway management guidelines that can be applied across various domains to improve implementation, promote standardisation and facilitate collaboration. Ahmad and Smith provide the accompanying editorial and ask, is there justification for yet another airway management guideline? They highlight how the methods used by Chrimes et al. are unique as well as highlighting issues which will need to be addressed by the authors in the forthcoming guidance. We simply cannot wait to see them!

Figure 1 Summary flowchart of the methodology used in the development of these guidelines. COVID, coronavirus disease 2019.

Last month, we brought together the authors of two papers with seemingly contradictory conclusions as well as an expert in aerobiology for #TheGreatAirwayDebate. The podcast has now been downloaded over a thousand times! We have a number of related papers this month, including this simulation study by Simpson et al., which shows that devices such as the aerosol box confer minimal to no benefit in containing aerosols during tracheal intubation. In their editorial, Turner et al. propose a framework for the safer adoption of a ‘McGyvered’ device, which includes a recommendation to not adopt, publish, endorse or disseminate via social media such devices without data to support safety. That said, social media was no doubt very useful during the early part of the pandemic for rapid knowledge transfer, as demonstrated by this editorial by Chan et al. along with their now famous infographic. Thankfully, we did not see any such devices attempting to solve the various issues associated with tracheostomy insertion, and instead this new guideline from McGrath et al. provides some sensible evidence-based practice recommendations. It will no doubt become very relevant once again for the second surge and beyond.

What are the additional risks during the peri-operative period attributable to new ways of working during the pandemic? Kane et al. report their retrospective observational cohort study and conclude there are low rates of COVID-19 infection in elective surgical patients despite a high burden of disease in the community. It seems the current bundles of peri-operative care along with stratified pathways work (Fig. 2). Should we be re-starting elective surgery? Well we obviously have and did so the short answer is yes, as safe surgery is essential for the management of non-communicable diseases and underpins good health and wellbeing. Efforts to ensure this can be done safely present us with enormous challenges that we are fighting collectively. This observational study by Okonkwo et al. is an excellent example demonstrating how it was done for paediatric surgery in north-west England

Figure 2 Urgent elective surgery care bundle during COVID‐19 surge. Details of key elements of the urgent elective surgery care bundle from planning to postoperative follow‐up and COVID‐19 status tracking. PPE, personal protective equipment.

We published recently an international multidisciplinary consensus statement on the prevention of opioid-related harm in adult surgical patients, and this new editorial by Bowen et al. calls for current ‘track and trigger’ tools to be updated to reduce opioid-induced ventilatory harm. They discuss risk factors, incidence, detection, sedation scores and track and trigger systems. Opioid-induced ventilatory impairment is a preventable iatrogenic harm, yet some patients have no identifiable risk factors. Is it time we monitored all patients receiving opioids for acute pain with a better designed track and trigger tool? The authors suggest so. 

When anaesthesia is maintained with intravenous drug infusions, real time analysis of the achieved concentrations is not routinely available. This new prospective observational study from Van Hese et al. finds that although target-controlled administration of propofol and remifentanil using the Marsh and Minto models allows clinically safe and stable conduct of anaesthesia, there were significant inaccuracies in both plasma and brain concentration predictions of these models. The Minto pharmacokinetic parameter set resulted in an underprediction of the plasma remifentanil concentrations by 72% and an overprediction of brain tissue remifentanil by 14%. Furthermore, the Marsh model showed an overall underprediction in both plasma and the brain by 12% and 81%, respectively, meaning that the measured brain tissue concentration was 81% higher than the effect‐site concentration predicted by the Marsh model (Fig 3). Irwin et al. suggest that some of the assumptions on which we base our models may be incorrect, and go into detail about what these models and assumptions are as well as their accuracy. They suggest that the issue of effect‐site concentrations probably exists for all anaesthetic drugs as a result of complex interactions with the blood brain barrier, including inhalational anaesthesia. After all, what we are measuring is the end tidal concentration and not the concentration of drug at the effect site in the brain. 

Figure 3 Relation between the performance error (PE) and the target concentrations in plasma and the brain. (a) Predicted TCI target concentrations of remifentanil were calculated using the pharmacokinetic parameter sets of Minto. Remifentanil plasma concentration (open circle); remifentanil effect‐site concentrations (filled circle). (b) Predicted TCI target concentrations of propofol were calculated using the pharmacokinetic parameter sets of Marsh. Propofol plasma concentrations (open diamond); propofol effect‐site concentrations (filled diamond).

Elsewhere we have: a review of COVID-19 infection risk during elective peri-operative carea statistical take on R0 (or more precisely, RE)a randomised study of programmed intermittent epidural bolus vs. patient centred epidural analgesia for maintenance of labour analgesia; and a study of the association of lung ultrasound images with COVID-19 infection in an emergency room cohort. Over in Anaesthesia Reports we have reports of: the use of the erector spinae block in obstetricsacute pulmonary oedema and hyperchloraemic metabolic acidosis following operative hysteroscopy using sodium chloride 0.9%apnoeic ventilation for shared airway surgery; and a novice anaesthetist working and living with malignant hyperthermia.

Finally, we will soon be publishing our 2021 supplement issue which is all about regional anaesthesia. Watch this space for some exciting news about how we aim to bring some of the great content to you in a new digitally immersive and interactive format! 

Mike Charlesworth and Andrew Klein

Time to plan and time to act again — but this time it’s different (Part 2)

“The only certainty in a pandemic is uncertainty”

While there is much that has improved in our understanding and management of COVID-19, there remains a significant concern about how we will deal with and get through this second surge of the pandemic. In some respects, there was more certainty during the first surge than there is in the second. We were certain that all but the most essential healthcare services were to cease. We were certain that all of our time was to be spent addressing the immediate crisis. We were certain about what we were allowed to do, who, how and where we were allowed to meet others, how our income was going to be safeguarded. We were certain that we did not know enough about this disease, but neither did anyone else. We were certain that our resource-capacity for testing, contact tracing, staff protection, PPE, critical care services were going to be stretched to the limit. We were certain that we were all in it together.

Those certainties have all but disappeared, and we have been left in dark territory without a light. Despite all of the lessons we should have learned in the first surge, there remain many we have failed to learn from, and there remain new hurdles for us to overcome. The healthcare-specific challenges are compounded by the fact that this surge will occur during the winter at a time when respiratory illness, hospital workload and mental health stressors are at their greatest.

Uncertainty in non-COVID-19 services

There is a moral and practical need to maintain non-COVID-19 work alongside surge-related activity. While all but genuine emergency work was postponed in the first surge, this is no longer feasible. There is now therefore a massive backlog of elective work the NHS has committed to both maintaining that elective clinical work and ensuring it continues to deliver healthcare services for all needs. This will pose new challenges which may be at least be equal or even greater than the challenges of the first surge. There is no new capacity in the NHS, but we will undoubtedly need to expand ICUs again, this time while protecting peri-operative pathways. The Anaesthesia-ICM hub has published guidance on how this may be achieved and in it emphasises the important of co-ordinated planning and collaboration between anaesthesia, surgery and critical care. There is likely to be a need for increased liaison and mutual aid not only involving critical care but also elective surgery. This may be between hospitals, regionally or nationally. To achieve this, departments of anaesthesia need to engage with their critical care colleagues if they are separate and it is likely that regional anaesthetic networks, similar to existing critical care networks, will need to be established. The Nightingale facilities (they lack the breadth of structures and services to be called hospitals) remain an important part of the response but only if the rest of the NHS is failing. Critically, Nightingale facilities provide space but not staffed space. So, if opened they will need to be staffed by the same staff who currently work in the very hospitals the Nightingales are designed to decompress. Their use will be a sure signal that the normal NHS is overwhelmed and will likely only occur when quality of care is already decreasing. We must hope they lie idle.

Maintenance of hospital safety

There is the challenge of keeping hospitals, their staff and patients safe from COVID-19. During the first surge hospitals were effectively closed except for COVID-19 patients and true emergency care. The country was in lockdown, schools, universities, pubs and restaurants were closed and social mixing was non-existent. The mantra was ‘protect the NHS’. Yet despite this the rate of infection in hospitals was three- of four-fold higher than in their communities – in one hospital almost half of healthcare workers became infected in a 3-week period. Hospitals such as Weston General and Hillingdon Hospitals had to close temporarily because of COVID-19 outbreaks. In the second surge, ‘the NHS is open’, elective care will continue while in the community town centres, schools and pubs are open and social contact is much increased, and adherence to guidelines has dropped as confidence in these has fallen. The number of staff off work due to illness or precautionary self-isolation as family members are in contact with others is already noticeable and impacting on delivery of care. To worsen matters, barriers such as self-isolation for 14 days before elective admission to hospital and use of high level PPE in elective patients have been removed so that patients may be admitted after no more than 3 days self-isolation (which, based on viral dynamics provides little if any barrier) and for these patients  transmission-based precautions such as increased levels of PPE or fallow theatre periods are currently not recommendedWard-based outbreaks can fuel nosocomial infection and currently approximately 10% of patients in hospital with COVID-19 acquired it there, with rates much higher in some locations. These patients are set for a difficult course: almost one in four surgical and medical patients who develop COVID-19 in hospital will die: far higher than if acquired in the community. Hospital outbreaks lead to patient and staff harm and ward closures, but also removal from work of large numbers of staff making it difficult to run services: we must avoid them at all costs. Hospitals need to monitor local and in-hospital infection rates to determine if and when the barriers that have been lowered need once more to be raised. The flux of patient risk pathways, be it red/amber/green; high/medium/low risk; COVID-free/COVID-positive or any other permutation that varies both temporally or spatially, has thrown healthcare workers into a constant state of confusion. Consistent, well-designed pathways for patients should be agreed upon and not be updated reactively, but rather planned proactively. Last but not least, hospital staff need to improve their behaviour to reduce transmission within hospitals. Social distancing, adhering to the designated numbers of people in any room, strict and proper wearing of facemasks and high infection control standards are essential. Despite weariness and the need to relax and decompress, it is not acceptable for the staff coffee room, doctors mess or departmental offices to be transmission hubs for the virus. 

Staff wellbeing

Mental health problems have increased across society during the pandemic. Hospital staff are significantly affected and it is likely that major changes in healthcare worker support will be needed to address the psychological harm already caused. The jump from a traumatic first surge, to the non-COVID-19 recovery, followed once again by a COVID-19 surge has left healthcare professionals fatigued and verging on burnout. Data suggest that more than half of all frontline healthcare workers are suffering either anxiety, depression or PTSD. This psychological burden will be carried forward to this second surge, leaving even greater uncertainty about the wellbeing of the very individuals on whom our healthcare service is dependent. Further, shielding of at-risk individuals is no longer required, and so healthcare workers with higher personal risks may have a significant increase in their absolute risk. Those with the power to do so must act, and we need to look after ourselves and our colleagues, actively managing our own mental health and workload, staying alert for signs in others and supporting those who are struggling. The Association of Anaesthetists and Intensive Care Society amongst others have provided excellent resources and these should be used alongside professional support. 

The world around us

Our lack of confidence in predicting the world around us has cast a further shadow on this second surge. Social restrictions change day to day, region to region, and country to country. Financial stabilityjob security, and government support have all become less predictable for many  families. Travel restrictions have meant that a large proportion of the healthcare workforce who have settled in the UK are unable to visit family members abroad. Political disquiet, both in the UK and globally, add to the ongoing state of flux. Leadership that provides long-term strategies and vision appear to be in short supply, given the predictability of many of our current challenges. And of course, there remain questions regarding the role of a potential vaccine on our ability to get through the pandemic. 

Hope

We are headed into the darkness of a long winter in which every aspect our lives will be affected. This winter is predicted to be one of the most challenging we are likely to face. However, the darkness and the surge will pass. We have always found ways of coming together and finding strength in adversity, and the strength of our healthcare workforce, both as individuals and as a community, will overcome the challenges ahead.

The first surge passed and so will this one.

Tim Cook and Kariem El-Boghdadly

Time to plan and time to act again — but this time it’s different (Part 1)

The second surge is upon us and we need to act, but as we do it is also worth reflecting on what we have learnt in the last 8 months. It can reassure us that we have done this before, that we know how to respond, to reflect on how much we know now compared to March and how much care for patients with COVID-19 and their outcomes have improved. There is much to celebrate. At the same time we need to be cautious to avoid complacency, to acknowledge the harm done to many by the first surge and to understand how the response and challenges will differ this time. Here we focus on positive reflection, in part two we will consider the challenges.

In March we wrote a blog highlighting the potential impact of the coming SARS-CoV-2 infection and the need to actively prepare for an influx of ill and critically ill patients. What has happened since is, as they say, ‘history’ and will remain so for decades to come.

Casting our minds back to March, it is difficult to remember quite what turmoil we were in. One of us works in a central London teaching hospital, which like many was intensely busy. The other, who was shielded from frontline work for several months, works in a district general hospital in the south west where the pandemic was considerably less severe, yet hospital services were still restructured, stretched and pressurised. In both hospitals critical care units were expanded, staff retrained and redeployed and the NHS came together as one to meet the coming challenge. During this period what both of us remember most clearly is uncertainty and fear. That fear was, in part, borne of the uncertainty – relating to personal, colleague and family safety, the unmanageable estimates of clinical activity, concerns over our ability to cope with the rigours of work and of what would follow. 

It is important to remember and acknowledge those fears. Also, to remember the acute physical and emotional exhaustion most experienced, due to increased duration, moral burden and acuity of work, compounded by information overload as we planned for and learnt daily about the pandemic response. For many, the impact of spring 2020 will be with them forever, through family loss, moral injury or unexpected and unwelcome experiences that have left shadows that will not lift. At home, the lockdown was unfamiliar, unwelcome and inexorable. For the fortunate, the shadows did pass and summer gave some respite: there was a rather brief period of release from lockdowns and overwhelming work, and perhaps some optimism and time to rest.

It is now clear that we are amid a significant second surge. Much of the country is in some form of local lockdown. We can only hope the government will not demur again over the implementation of significant and effective rules to control community viral transmission and regain control, but popular and professional confidence is not high. A tiered system of local lockdown is to be welcomed, but why it has been created seemingly on the hoof in the midst of an exponential rise in cases, admissions and deaths, rather than planned and announced in the summer months is difficult to fathom. Many are concerned these measures will not be enough and tougher ones will soon follow.

Lessons learnt in the first surge

Despite these many concerns, there are also many reasons to be positive.

We are better prepared 

Our preparation in terms of knowledge of the virus and how to respond to it is immeasurably advanced from 8 months ago. Hospital infrastructure is such that separation of COVID-19 and non-COVID-19 pathways should not need to be hastily constructed, oxygen supplies are established and should not be at risk of exhaustion. The stress of shortages of PPE and drugs should not be repeated. The plans for expansion of critical care services are well developed, and skills acquired by many colleagues in the spring will have been retained and can be rapidly redeployed.

We are more agile

In a short time, we have transformed the way we work and communicate. Video conferencing, virtual patient consultations and working from home have transitioned from ‘not possible’, through ‘possible’ to ‘essential’ and now become embedded in everyday medical life. Lines of communication between frontline clinicians and senior management have become necessarily more open and we have learnt the importance and value of direct contact with colleagues in business modelling, estates and housekeeping, to mention only a few. Clinical networks, most particularly for critical care, have been reinvigorated and have become central to planning for and responding to challenges on a regional or national level, rather than as single hospitals. These new, established ways of working provide an opportunity for more inclusive but leaner and more agile communication and decision-making. 

We are treating COVID-19 more effectively

Early strategies of fluid restriction, avoidance of non-invasive ventilation, early tracheal intubation and high levels of PEEP were, in retrospect, not optimal. These have been replaced by fluid restoration to improve ventilation-perfusion mismatch, improve gas exchange and reduce risk of acute kidney injury, pragmatic use of non-invasive ventilation and high-flow nasal oxygen, prone positioning (both awake and once intubated), timely tracheal intubation and enhanced anticoagulation strategies. 

Mortality in our hospitals has reduced and over 3 months ICU mortality  fell from 60% to 42% globally and in the UK from 44% to 34%. We have benefitted from pragmatic, rapidly deployed and extensively adopted research, much of which has centred on the UK including the RECOVERYREMAP-CAP and genomicc studies. We now know that dexamethasone saves lives once patients require oxygen and that remdesivir may shorten illness in milder hospitalised cases but does not save lives. Importantly we also know that the antiviral combination lopinavir with ritonavir has no effect, that hydroxychloroquine is an ineffective treatment and that in combination with azithromycin it is likely harmful. This important knowledge enables clinicians to focus on what does work and to continue with research to determine the role, if any, of treatments such as convalescent plasma, monoclonal antibodies such as tocilizumab, the cocktail produced by Regeneron and other small molecules. The importance of these speedily conducted, high quality, large scale randomised controlled trials cannot be overstated and should not be underestimated. These studies have provided clear and definitive answers to what we should and should not do and have been the only brake to scientific misinformation arising from small, poorly conducted or even occasionally fraudulent research. In the aftermath of the pandemic, one of the key actions must surely be to re-examine how research is undertaken in the UK – to break down the excessive regulatory barriers and re-enable democratic involvement in large scale clinical studies without the current bloated burdens to patients, clinicians and researchers. 

We are better protected

In the early stages of the pandemic, uncertainly regarding the selection of appropriate PPE and concerns over shortages were a major concern. Frequent changes in guidance from public health bodies and poor communication increased anxiety and decreased confidence. At its heart, PPE strategy is simple – provided you know which mode of transmission you wish PPE precautions to protect against, the choice of PPE is rather simple. However, much doubt has arisen because of a lack of clarity over which modes of transmission should be protected against. The mainstream advice was that SARS-CoV-2 transmission in healthcare settings is via droplet and contact transmission, except during the conduct of a select group of interventions –aerosol-generating procedures (AGPs). However, a wealth of data shows that coughing and sneezing, as well as loud talking and singing, create aerosols. Patient-facing healthcare workers have an increased risk of SARS-CoV-2 infection and harm or death. Amongst healthcare workers, there is an association between those who perform tracheal intubation and subsequent COVID-19 symptoms, but amongst anaesthetists and intensivists as a group, there is a relatively reduced risk of infection with SARS-CoV-2 or death from COVID-19. There is emerging evidence that some AGPs may not be aerosol generating, including airway management during tracheal intubation and extubation and use of non-invasive ventilation and high-flow nasal oxygen. Whether the safety of anaesthetists and intensivists (and those they work with) is due to higher level PPE, safer infection control behaviour, diminished viral secretion at the peak of illness or because AGPs are not AGPs remains an open question. 

Overall therefore we can reflect in many ways on progress, work well done throughout the community, hospitals and by researchers. These are, in a year of gloom, reasons to be optimistic.

Tim Cook and Kariem El-Boghdadly

Science bites back

This month, we were delighted to publish two contrasting articles on aerosolisation during tracheal intubation. The first by Brown et al. was published on the 6th of October, and has since become our fourth most popular paper on social media, ever! They conducted an experiment involving quantitative aerosol measurements during tracheal intubation and extubation in real-time in ultraclean ventilation operating theatres. They found that tracheal intubation produces a barely recordable increase in aerosol, which is at odds with previous retrospective evidence that was used to designate tracheal intubation as an aerosol generating procedure. Remarkably, this was followed only a few days later by a study from Dhillon et al. which seems to suggest the opposite. They found that face-mask ventilation, tracheal tube insertion and cuff inflation generated small particles 30-300 times above background noise that remained suspended in airflows and spread from the patient’s facial region throughout the confines of the operating theatre. This all begs the questions, who was right? We are looking forward to the associated editorial and we hope to bring both groups of authors together to discuss the many complicated issues at play. We are, however, thrilled that we are now beginning to see the science tackle some of the key clinical questions which affect practice as we enter what seems to be the second wave of COVID-19 in Europe. 

Turning attention back to the November issue, aerosol generation and airway management remain key topics. This prospective international multicentre cohort study from El-Boghdadly et al. was first published four months ago and is the first output from the IntubateCOVID registry (Fig. 1). They found that around 1 in 10 healthcare workers involved in tracheal intubation of patients with suspected or confirmed COVID-19 subsequently reported a COVID-19 outcome. When interpreting these data, it is worth remembering the limited availability of tests for healthcare staff and members of the public alike at the time data were collected. This and many other aspects of the study are discussed in the paper and have been commented on by others in associated correspondence. Kakodkar et al. undertakes some mathematical manipulations to estimate a baseline risk after a COVID-positive aerosol-generating procedure, which is generally reassuring for those treating ‘green’ pathway patients. Crawley and Maguire likewise discuss airway management in the COVID-19 era, oxygenation, videolaryngoscopy, risk to healthcare staff and future directions, considering the findings of El-Boghdadly et al

Figure 1 Symptoms reported in the 184 participants meeting the primary endpoint.

Another risk to healthcare staff is of the future legal implications of decisions taken during the present time.This new review from Coghlan et al. outlines the broad framework within which we can consider the medicolegal and ethical aspects of some of the more readily identified issues experienced during the surge in demand for critical care. In particular: legal aspects of care and the legal and ethical aspects of rationing critical care. The associated editorial from Ferguson and Johnston provides some commentary, and call for us all to move ahead collectively, learning lessons and effecting changes that provide long-term benefit. How frequently does anaphylaxis occur during pregnancy, what are the causative agents and how is it managed? This new population-based multinational European study by McCall et al. finds a similar incidence across five European countries of 1.5 per 100,000 women among almost 4.5 million births. Most reactions happen around the time of birth, and there are wide variations in management strategies. Savic and Lucas argue that although this may seem reassuring at first, there is a risk of underreporting and there is a need not to overlook this important differential when an obstetric patient deteriorates unexpectedly. 

Figure 2 Video calls between ICU patients and their family: data protection issues. GDPR, General Data Protection Regulation; MCA, Mental Capacity Act.

How well do you understand the COVID-19 coagulopathy spectrum? This new editorial from Thachil and Agarwal describes immunothrombosis, localised pulmonary and systemic coagulopathy antithrombotic management, the role of viscoelastic testing, bleeding and future directions in the area. Although outcomes may improve as our understanding of the coagulopathy spectrum increases, how can we better assess the risk to our own health that COVID-19 poses? This new review from Tim Cook is a must read for all, as it brings together all the relevant evidence to remind us that age is the chief risk factor. Furthermore, absolute rather than relative risk is more important and dynamic, particularly in the context of healthcare workers. The paper includes an excellent risk assessment tool, and we encourage organisations to consider the interaction between personal and environmental risk, as well as mitigation measures, rather than just personal risk alone. Finally, Thornton et al. present recommendations for management of the airway and lung isolation for thoracic surgical patients during the pandemic. Their paper has generated much discussion already and we hope its publication has kept healthcare staff safe, at a time where thoracic surgery continued for patients with lung cancer.

Figure 3 Antithrombotic management of COVID‐19 coagulopathy based on D‐dimers and platelet counts.

Elsewhere we have: a narrative review of tracheal tube size in adults undergoing elective surgerya randomised trial of fibrinogen concentrate during scoliosis surgerya randomised controlled trial of intra-operative dexmedetomidine in children; and a randomised trial of intravenous dexamethasone after volar plate surgery. Over in Anaesthesia Reports, we have reports of: extracorporeal carbon dioxide removal in a patient with COVID-19surgery for tracheal obstruction due to a tumouran emergency caesarean section in a patient with pre-eclampsia and multifactorial thrombocytopeniamallet finger in an anaesthetist; and many other interesting cases. Finally, make sure you book your place at #WSMLondon21, as we go virtual! Our new Editor Ed Mariano is speaking about lessons learned from the US opioid epidemic, and speakers at the journal session on Thursday morning include Seema Agarwal and Laura Duggan. 

Mike Charlesworth and Andrew Klein

Kicking on while it’s kicking off

This month, we are beginning to see what many think may be the second surge of COVID-19 across Europe and elsewhere. Although some of the papers in this month’s issue were written and published during the first surge, they are now arguably more important than ever. First, Cook and Harrop-Griffiths discuss the many challenges of planned surgery, which includes time-critical and wholly elective procedures, in the context of the many issues affecting hospitals and the services they offer. We need to: manage the increased ICU activity associated with COVID-19; make hospitals safe places for staff, patients and relatives; ensure all patients are treated fairly; and look after our most important resource, our staff. Again, the challenges back in May are the same as those we face now and there are no easy answers. Professor Pandit suggests modelling might play a role when efforts are made to match demand and capacity (Fig. 1). Key questions include: how to set capacity; how to fund increased capacity; how to manage COVID-19 pathways; and how to manage demand. The current situation has forced us to increase capacity in the NHS and encouraged us to ask difficult questions about how we manage demand. As anaesthetists, we are well placed to influence the national agenda, which is what is needed to help us to learn to live with COVID-19.

Figure 1 Demand (which can be measured variously; horizontal black line) is constant over time so optimal capacity (red line 1) is easy to estimate. For varying demands shown, although mean demand is identical to the horizontal black line, the optimal capacities required to meet all the demand all the time increase (from dotted red line 2 to solid red line 3) as variation increases. However, this results in wasted capacity when demand falls to less than the peak. 

Should we routinely use hyperoxgenation in adult surgical patients whose tracheas are intubated? Weenink et al. argue that we should, and cite beneficial effects including: less surgical site infections; reduced postoperative nausea and vomiting; improved safety margins; and the use of hyperbaric oxygenation. These, they argue, outweigh any adverse effects, and they recommend the intra-operative administration of 0.80 fraction of inspired oxygen to non-critically ill adults whose tracheas are intubated. On the other hand, Sperna Weiland et al. go into more detail on the potential harms of hyperoxia, and argue its use to prevent surgical site infections is not supported by existing evidence. Where do you stand? Let us know over on Twitter!

This new randomised, crossover, simulation study from Schumacher et al. is the first to compare the use of modern respirators and powered respirators during advanced airway management procedures (Fig. 2). They found that videolaryngoscopy proved to have certain advantages whilst wearing respiratory protection, regardless of the type of protection used. When flexible bronchoscopic intubation was attempted, the use of protection did not significantly prolong attempts. Participants rated heat and vision significantly higher in the powered respirator group; however, noise levels were perceived to be significantly lower than in the standard respirator group.

Figure 2 Powered air‐purifying respirator with hood (left) and Standard air‐purifying respirator (right).

This systematic review and meta-analysis of observational studies from Armstrong et al. has an Altmetric score of 1148, which makes it our second most popular paper on social media, ever! It provides a message of hope for all of us facing a potential second wave, and shows how we have been able to adapt and improve outcomes for critically unwell patients with COVID-19 as our experience grows and learning accelerates. It is essential reading for all. Important also is this review of resilience strategies to manage psychological distress among healthcare workers during the COVID-19 pandemic, which builds on experiences from the SARS-CoV-1 and Ebola outbreaks. This new review from Sidebotham is a thought-provoking piece for many reasons, as it challenges everything we think we know about evidence-based medicine in peri-operative medicine and critical care. He concludes that, with the use of Bayes’ theorem, small underpowered randomised trials reporting weakly significant p values have a false positive risk of at least 50%. Likewise, large multicentre trials in critical care appear to have a high false negative risk. Is most of the evidence that underpins our clinical practice wrong? Charlesworth and Pandit outline some possible explanations and solutions, though the thought that every trial ever performed might need to be continuously repeated might be too much for some. Although such statistics may seem complex and inaccessible for most, they argue the way in which clinicians treat patients (and interpret clinical trials) is in fact Bayesian (Fig 3). 

Figure 3 The relationship between prior knowledge, clinical evidence and posterior knowledge from Bayes’ theorem are shown, for an example where the trial result (clinical evidence) shifts our final belief (posterior) towards accepting the intervention. Note that the precision (reflected in the width of the bell curves) of the posterior knowledge is tighter than prior knowledge and clinical evidence. The trial result (clinical evidence) may indicate a high probability of success of intervention, but our final belief will be tempered in a Bayesian framework: we do not accept this blindly. The distance between the distributions, their position and their precision arguably tell us more about the probability of success of an intervention than simply setting out to prove that something is true or false.

Elsewhere this month we have: a mixed methods analysis of factors influencing change in clinical behaviours of non-physician anaesthetists in Kenya following obstetric anaesthesia training; a study of surgical cancellation rates due to peri-operative hypertension; a study of the clinical validation of bioreactance for the measurement of cardiac output in pregnancy; a review of neuraxial anaesthesia and peripheral nerve blocks during the COVID-19 pandemic; and a qualitative systematic review of the role of serratus anterior plane and pectoral nerve blocks in cardiac surgery, thoracic surgery and trauma. Over in Anaesthesia Reports, we have a report of extraconal orbital emphysema secondary to barotrauma in a ventilated patient with COVID-19 and a persistent left superior vena cava with partial anomalous venous return in a liver transplant patient. We are delighted to have appointed four new Editors to the Anaesthesia and three new Assistant Editors to Anaesthesia Reports. They are: Ed Mariano; Louise Savic; Iain Moppett; Ben Morton; Maryann Turner; Rose Kearsley; and Lachlan Miles. In addition, we are delighted to announce that our new trainee fellow for 20/21 will be Craig Lyons from Dublin. Congratulations!

Finally, make sure you join us for our webinar on Saturday morning to find out who has won paper of the year together with some excellent presentations on the best peri-operative medicine research around in 2020

See you on Saturday!

Mike Charlesworth and Andrew Klein

The gift of life

Earlier this year, the law in England changed to an ‘opt-out’ system for organ donation. This means that if you are not in an excluded group and have not confirmed whether you want to be an organ donor, it will be considered that you agree to donate your organs when you die. This month’s issue provides several brand new clinically-relevant updates in the field of solid organ transplantation from experts from around the world. 

Wales moved to an ‘opt-out’ system in 2015, whereas the rest of the UK maintained the ‘opt-in’ approach. This analysis from Madden et al. examines the effect of this legislative change on consent rates for deceased organ donation in Wales from 2015 to present. They found there was a significant increase as compared with England, although the impact was not immediate and took several years to take effect. There has been little coverage in the literature on risk factors in the donor for poor post-transplant organ quality and the role of donor management before organ retrieval. Bera et al. argue prevention of injury and promotion of repair before organ retrieval, by targeting specific pathological pathways, offers novel mechanisms for donor management beyond just physiological stabilisation

Organ donation after brain death (DBD) remains the deceased organ donation pathway of choice (Fig. 1). Manara et al. argue that increasing DBD donors in the UK can be achieved primarily by increasing consent rates to those comparable with the rest of Europe. Their work is simply everything you need to know about the current status of DBD organ donation in the UK. Donation after circulatory death (DCD) in the UK has increased over the last decade, due partly to cultural changes in end-of-life practices, as well as overcoming various ethical, legal and professional barriers. Gardiner et al. tell the story of the rise of DCD, and use data derived from publicly available sources to do so (Fig. 2). The question of how to define ‘death’ is an age-old ethical dilemma that continues to cause confusion and controversy. Some might suggest it can be defined as either circulatory-respiratory or neurological. Gardiner et al. argue there are not two different types of death, and it is not true that ‘irreversible’ means ‘permanent’ only when applied to the cessation of circulatory and respiratory functions. In their review article, they set out arguments for why permanent brain arrest is the true and sole criterion for the death of human beings. Finally, Cooper et al. set out the reasons that the ethical and practical ‘problem’ of consent for interventional research in deceased organ donors is far from resolved. They argue a failure to appreciate this may have serious implications for all, such as the prolongation of research processes or the loss of public trust in medical research generally and organ donation specifically. 

Figure 1 Schematic overview of the process of deceased organ donation.

Figure 2 Number of UK DCD cases and contribution as a percent of total deceased donations over time. Columns – number of DCD cases; Line – percent contribution of DCD (compared with total DBD and DCD).

Deep neuromuscular blockade during laparoscopic surgery might facilitate lower intra-abdominal pressure and provide adequate operating conditions, and has been proposed to have a number of other benefits. This new randomised controlled trial from Boggett et al. finds that deep neuromuscular blockade did not improve cognitive recovery or other recovery domains, and did not facilitate a reduction in intra-abdominal pressure. Many have long advocated the use of objective neuromuscular monitoring to avoid residual neuromuscular blockade (NMB). This new retrospective observational study of 30,340 cases from six Danish hospitals finds that acceleromyography was used in 88% of cases in six Danish hospitals where a non‐depolarising NMB drug was used, and in 30% of cases where succinylcholine was the sole NMB drug. These are amongst the highest rates of NMB monitoring reported. Bowdle and Jelacic urge us all to use routine quantitative twitch monitoring, and argue the trachea should not be extubated until the train-of-four ratio reaches a normalised value of at least 0.9 (Fig. 3).

Figure 3 Last recorded TOF values in 13,562 cases. A TOF value of 100 depicts the scenario where no fade is seen and the ratio is 1.0. The vertical line represents the median at 97, while the mean (SD) is 97.4 (24). 

Back in May, we were delighted to publish a new PROSPECT guideline for oncological breast surgery. This month, McCartney and Abdallah provide the context, and conclude the guidelines are an important addition to our knowledge. The next challenge, which is the same for any other new guideline, will be to see if they can be implemented with the help of our surgical and other peri-operative colleagues. Direct oral anticoagulant prescriptions now exceed those of warfarin and are increasing annually. Mayor and White call for a more pragmatic approach to these agents in the peri-operative period for patients undergoing hip fracture surgery, by focussing more on the risks associated with delay. Their editorial is essential reading for all anaesthetists, and new guidance for those caring for these patients is eagerly awaited. Lastly, Agarwal and Laycock provide their thoughts on the utility of point-of-care testing and fibrinogen concentrate in postpartum haemorrhage

Elsewhere we have: a randomised controlled trial of the effect of 6% hydroxyethyl starch 130/0.4 on kidney and haemostatic function in cardiac surgical patientsa database analysis of spinal versus general anaesthesia for surgical repair of hip fracture and subsequent risk of morbidity and mortalitya systematic review and meta-analysis of peri-articular infiltration analgesia for should surgery; and a celebration of the achievements and challenges in systematic reviews of evidence in peri-operative care as the Cochrane Anaesthesia Review Group turns 20. Over in Anaesthesia Reportsa report of the use of rocuronium ‘priming’ for tracheal intubation in COVID-19 patients has received a lot of attention on Twitter, as did a report of recurrent massive pulmonary emboli in a critically ill patient with COVID-19 and awake tracheostomy in a child with respiratory distress due to a retropharyngeal abscess

Last week, we held a TweetChat with Professor Tim Cook about his new paper on risks to health from COVID-19 for anaesthetists and intensivists. The paper was received extremely well on social media and generated much debate about the use of risk assessments for all staff members, which he argues should include environmental risk and mitigation strategies as well as personal risk. You may have seen also this new paper from Bampoe et al. about immune seroconversion to SARS-CoV-2 in frontline maternity health professionals, which was featured all over the mainstream media. 

Finally, we hope you can join us for our presentation of ‘Paper of the Year’ on the 26th of September, which also includes presentations on top airway and subspecialty papers, as well as the pitfalls and perils of publishing. 

Mike Charlesworth and Andrew Klein

Surviving the COVID-19 information pandemic

The COVID-19 pandemic has affected all aspects of life in many different ways, and one clear theme is the saturation of our inboxes, newspapers, televisions and medical journals with COVID-19-related content. As a journal, we handled and made decisions on a record number of submissions over recent months, and we have: carefully selected 74 COVID-19 papers for publication, which are free to access forever; registered over 1,000,000 full text downloads; and reached over 2 million users on Twitter. However, the sheer volume of information may have, at times, resulted in cognitive overload, more so at times of escalated clinical activity. Kearsley and Duffy discuss all this and more and ask, have we managed the information surge? There are many lessons we can and must learn for the future.

The death of healthcare workers infected with SARS-CoV-2 has received much attention in the media, but there exists no central registry for such deaths. Kursumovic et al. argue the need for robust data and analysis, as the current and future NHS workforce need to feel safe and confident that they will be protected at work. A brand new review from Professor Cook describes in more detail the occupational risk associated with COVID-19 for anaesthetists and intensivists, and is essential reading for all. Patients with severe respiratory failure due to COVID-19 might be referred to a specialist centre for venovenous extracorporeal membrane oxygenation, but how are decisions about acceptance to such centres made? This editorial from Zochios et al. provides a sample decision algorithm, which can be adapted as pressure on resources changes over time (Fig. 1).

Figure 1 Proposed decision algorithm for initiation of venovenous extracorporeal membrane oxygenation (ECMO) in COVID‐19–associated respiratory failure. RESP, respiratory ECMO survival prediction; PaO2, partial pressure of oxygen in arterial blood; FiO2, fraction of inspired oxygen.

The ‘aerosol box’ is a novel device typically consisting of a plastic cube covering a patient’s head and shoulders. At the beginning of the pandemic, inventors of the box were praised by many for their ingenuity. There was, however, no published research demonstrating safety and/or efficacy. This paper by Begley et al. now has five citations and an Altmetric score approaching 400! In it, they report data suggesting aerosol boxes significantly slow intubation times and may even cause damage to personal protective equipment. Another recent paper by Simpson et al. supports this conclusion and goes further by suggesting the risk of aerosol exposure may even be increased. The question is, should we be more cautious about the widespread introduction of novel devices such as this in the future, or is practice before evidence sometimes justified? Other COVID-19 papers this month include narrative reviews of: airborne transmission of SARS-CoV-2 to healthcare workerspoint-of-care lung ultrasound; and patient blood management

The use of high-flow apnoeic oxygenation during laryngeal surgery is something most of us are familiar with, either through clinical practice or the rapid increase in associated publications describing its use. This new prospective observational study from O’Loughlin et al. finds that the use of low-flow tracheal apnoeic oxygenation with a narrow-bore catheter to oxygenate non-obese patients for short duration laryngeal surgery is supported, as it provides adequate operating conditions and without excessive accumulation of carbon dioxide (Fig. 2). Patel and El-Boghdadly remind us that apnoeic oxygenation is nothing new, and was first described 350 years ago. They highlight various limitations of the study by O’Loughlin, and the lack of novelty regarding the study findings. There remain many unanswered questions, such as: ideal flow rates for nasal high-flow apnoeic oxygenation; the potential benefits of lower concentrations of oxygen delivered with low flows; and the prediction of safe apnoea times for individual patients. All in all, the lower you go, the lower the flow; the higher the flow, the longer you go (Fig. 3). 

Figure 2 Microlaryngoscopy view showing a 10‐French oxygen catheter in‐situ.

Figure 3 The underlying principles of per‐oxygenation, which includes pre‐oxygenation and apnoeic oxygenation and ventilation. Pre‐oxygenation ends when apnoea starts due to induction of anaesthesia and administration of neuromuscular blocking drugs. Thereafter, apnoeic oxygenation and ventilation and, in the setting of high‐flow nasal oxygen, transnasal humidified, rapid‐insufflation ventilatory exchange. This may continue until desaturation commences. Efficacy describes the time during which pre‐oxygenation achieves a pre‐determined end‐tidal oxygen concentration before apnoea commences. The apnoea time is the time between commencement of apnoea and arterial oxygen desaturation. Efficiency is the combination of pre‐oxygenation with apnoeic oxygenation and ventilation.

We all know we should consider using point-of-care viscoelastic testing during certain clinical scenarios, but many may not be confident to interpret the outputs of such tests. This is more so the case for trainees rotating between hospitals where different tests and systems are used. Rössler et al. developed the ‘Visual Clot’ as an alternative mode of presentation, and this paper describes its use amongst 60 clinicians. They conclude the 3D Visual Clot improves therapeutic decisions based on viscoelastic testing, as pathologies can be recognised more accurately, faster, with greater confidence and reduced perceived work‐load (Fig. 4). Ahmed and Agarwal ask whether or not an old dog can be taught a new trick in the context of visual spatialisation of viscoelastic testing and artificial intelligence. They argue that any system that can help a clinician to interpret complex variables effectively and rapidly, allowing them to initiate interventions accurately, is always going to be welcome. Finally, the recently published international multidisciplinary consensus statement on fasting before procedural sedation in adults and children was has attracted much attention, and this new editorial from McCracken and Smith provides some clinical context. They describe the many strengths and limitations of consensus statements, and the implications for clinical practice. Is it time to disassociate fasting before procedural sedation from fasting before general anaesthesia? There are no doubt strong arguments for and against, in an area where the evidence will always be far from perfect. 

Figure 4 Example scenario of a rotational thromboelastometry with a corresponding Visual Clot. The scenario displays a plasmatic factor deficiency, as shown by the prolonged clotting time (CT ) in the (a) rotational thromboelastometry EXTEM and INTEM channel or the missing plasmatic factors in the (b) Visual Clot. This scenario would be answered correctly by selecting ‘plasmatic factors’ as a treatment and nothing else.

Elsewhere we have: a study outlining how a reusable elastomeric respirator may be adapted to address N95 shortages during this and other respiratory pandemicsa quality improvement initiative examining the impact of a risk-stratified thromboprophylaxis protocola randomised controlled trial of the efficacy of quadruple treatment on different types of pre-operative anaemiaa prospective cohort study of tranexamic acid before lower limb arthroplasty; and a case series of pneumomediastinum following tracheal intubation in COVID-19 patients

Over in Anaesthesia Reports, the Assistant Editors have prepared two new editorials. The first by Charlesworth et al. summarises all reports published in the first half of 2020, including their key clinical messages. Bailey and Shelton discuss indexing, metrics and social media, which is a truly fascinating read with something for everyone. Recent reports include: acute recurrent bradycardia with evoked potential loss during transforaminal lumbar interbody fusionfailure of standard tracheostomy decannulation criteria to detect suprastomal pathologycomputed tomography scanning in the prone position; and the use of separate-level neuraxial anaesthesia for caesarean delivery in a patient with a history of spinal tuberculosis

Would you like to join us either as an Editor for Anaesthesia or as an Assistant Editor for Anaesthesia Reports? We are advertising these posts now, and we would be delighted to hear from you!

Mike Charlesworth and Andrew Klein

The anaesthetic robotic revolution?

The July issue is now available online and next month will see a return to the distribution of printed copies of the journal to our readers. You can read all about the reasons for this, along with how we have adapted to the pandemic, in our new editorial which now features in our ‘accepted articles’ section. In this month’s issue, Biro et al. describe robotic endoscope-automated laryngeal imaging for tracheal intubation. A prototype robotic endoscope device was inserted into the trachea of an airway manikin by seven anaesthetists and seven novice participants. There was little difference between the groups in terms of success rate and duration of insertion (Fig. 1). Ahmad et al. list the many limitations of this study, such as the fact that tracheal intubation was not performed. That said, the device recognised glottic features and was able to steer the endoscope tip into the trachea automatically. This is truly novel. Will robots take our jobs? We only need to look to surgery to tell us that robots have made good surgeons better, and although anaesthesia might be an innovative specialty, we have not fully embraced the robotic revolution, just yet.

Figure 1 User interface composed of the tip camera video (a) and the device configuration feedback (b), and anatomical features detection (c to e). The square indicates the successful recognition of the laryngeal inlet. The white dot represents the detected entrance of the glottis, while the white cross aims into the direction the tip is pointing. This difference triggers the proposal to ‘move the device to the left’, which appears in the left upper corner of the screen. The entire larynx (double line square), the corniculate cartilages (dotted small square), glottis (full line square) and subglottic trachea (segmented square). On the video screen (a), these squares are colour coded for better differentiation.

This month’s issue contains several high impact papers on various aspects of caring for patients with COVID-19. First, Lyons and Callaghan discuss the use of high-flow nasal oxygen (HFNO) for such patients. We use it commonly for patients with respiratory failure, but there are theoretical concerns around the potential for aerosol generation. This is all challenged by the authors, who point to a lack of evidence on aerosol generation and the risk of infection with HFNO, and call for clinicians to remain open minded. The question is, do alternatives have a better risk-benefit profile, for both patients and healthcare workers? Ventilator splitting has received much attention, and this new paper describes how it might be achieved with standard hospital equipmentLee et al. report their experiences of battling COVID-19 from a tertiary academic medical centre in Singapore. Strategies included: containment; avoidance of health resource overburdening; optimisation of healthcare resources; and factoring in welfare and logistics. This can be compared with hospital surge capacity in a tertiary emergency referral centre during the COVID-19 outbreak in Milan, Italy. They issued an early warning (in late March) that hospitals should be prepared to face severe disruptions to their routine, and that it was very likely that protocols and procedures might require re-discussion and updating daily. The care of patients with chronic pain has been significantly impacted by the pandemic, and these new consensus recommendations from an international expert panel provide guidance on: the immune response; steroids; psychological, physical and social functions; in-person visits; telemedicine; biopsychosocial management; opioid prescriptions; anti-inflammatory drugs; and procedural precautions. Of course, no discussion of COVID-19 is complete without talking about personal protective equipment, and this review by Tim Cook is arguably the best there is. The infographic below contains all the key messages, but the full paper is well worth a read for everyone. You can also listen to a podcast on the topic from last month here

We also have a number of high-quality ‘NO-VID’ papers this month, including this narrative review of the anticipated difficult airway during obstetric general anaesthesia from Mushambi et al. They provide generic recommendations as well as updated decision aids for: the time and mode of delivery for a pregnant woman with an anticipated difficult airway; the general anaesthetic approach to such a patient; and an overview of all the included practice recommendations. This new safety guideline, jointly produced between the Obstetric Anaesthetic Association and the Association of Anaesthetists, describes practices around neurological monitoring associated with obstetric neuraxial block. Four main recommendations are given, which include: triggers to alert the anaesthetist; the use of straight-leg raise as a screening method; the likely timescale for resolution of neuraxial blockade; and the guidelines and policies maternity units should be expected to have in place (Fig. 2).

Figure 2 Summary of postpartum neurological deficits.

Elsewhere we have a study of the association of pre-operative anaemia with morbidity and mortality after emergency laparotomya prospective cohort study of clinician perception of long-term survival at the point of critical care discharge; and a retrospective observational study of variables associated with survival in patients with invasive bladder cancer with and without surgery. Over in Anaesthesia Reportsthis new report of a junior doctor’s experience of critical illness due to COVID-19 now had an Altmetric score of > 1000! It was featured by > 100 news organisations, including the mainstream media, and has won acclaim from doctors and patients alike. Other reports include: local anaesthetic resistance in a patient with Ehlers-Danlosintra-abdominal nasogastric tube placementparatracheal abscess formation following tracheal intubationthe anaesthetic management of a patient with an isolated cortical vein thrombosis for emergency caesarean sectiontransient paraplegia due to subarachnoid haemorrhage following spinal anaesthesia; and unexpected difficult airway management in a transgender female patient

Join us over on Twitter as we discuss every paper from the issue in detail, with each made free for a day for all!

Mike Charlesworth and Andrew Klein

Preventing major airway complications

Every anaesthetist fears the moment they might become faced with a ‘can’t intubate, can’t oxygenate’ (CICO) scenario, but thankfully such events are exceedingly rare. They nevertheless receive much attention in the academic literature. The results from this online survey of Australian and New Zealand anaesthetists finds that most hospitals keep CICO equipment in every anaesthetic room in dedicated packs. As this is probably not common practice elsewhere, maybe it is probably about time we all caught up. Kelly and Duggan discuss preparing for and preventing CICO events, and call for clinicians’ worldwide to examine the design of their working environment. At the same time, the need to prepare for CICO events is superseded, arguably, by the need to prevent them from happening in the first place. Perhaps it is good timing then, that Chrimes, Higgs and Sakles write in this month’s issue to welcome us to the era of universal airway management. Their guidelines are anticipated eagerly.

This new pilot study from Deng et al. is an excellent example of how such a study should be designed and reported. They present important data that will hopefully allow for a larger, definitive randomised controlled trial of standard vs. augmented systolic blood pressure management during endovascular thrombectomyWiles discusses the relevant literature on the relationship between anaesthetic technique, blood pressure monitoring and outcomes for patients undergoing mechanical thrombectomy after ischaemic stroke. He argues a greater focus on precision medicine is required, which includes individualised objectives and attention to detail. Is it time for bespoke haemodynamic targets? Such an aim might seem more biologically plausible than a simple choice between general anaesthesia and conscious sedation (Table 1).

AdvantagesDisadvantages
Airway protection with reduced risk of pulmonary aspiration of gastric contents (most patients do not present fasted).Slower door‐to‐groin puncture time and thus may delay vessel recanalisation.
Less patient movement which is desirable from the perspective of the interventional radiologist and may reduce procedural time and complications.Potential for a greater degree of iatrogenic hypotension
Lower potential for patient discomfort.Unable to monitor neurological status intra‐operatively.
Ensures direct anaesthetic involvement in the procedure which may secondary benefits such as: dedicated intra‐operative clinical monitoring; assessment and correction of volaemic status; and assistance with postoperative care destination (e.g. critical care admission).Risk of postoperative hangover effect with potential for POCD/POD.
Table 1 Advantages and disadvantages of general anaesthesia (including tracheal intubation) for mechanical thrombectomy.

This new editorial is extremely timely, even though it was written at the end of 2019. Kelly et al. discuss resilience in the context of lessons learnt from the military. They remind us that resilience is more than ‘toughness’, and involves the ability to manage the breadth, depth, intensity and chronicity of the demands placed upon us. In the wake of passing the peak of COVID-19 cases in the UK and elsewhere, the messages contained, such as strategies to improve team resilience, are essential reading for all. In early March, we received our first COVID-19 paper from a group of Italian authors documenting their clinical experiences and recommendations. It has since been cited 32 times and achieved an Altmetric score of > 340! We then went on to publish these consensus guidelines for managing the airway in patients with COVID-19, which has now been cited 34 times and has an Altmetric score of > 500! We hope these and other publications, such as this simulation study to evaluate the operational readiness of a high-consequence infections disease intensive care unit, have contributed to better clinical care during what has been an extremely difficult time for us all.

This new review from Lindsay et al. examines representation of patients in peri-operative randomised controlled trials in terms of age, sex, race and ethnicity. They found included trials were insufficiently representative, with race and ethnicity seldom reported. Overall, study populations were younger (Fig. 1), which perhaps presents issues in areas such as orthopaedic and trauma surgery research. They recommend that unnecessary age discriminatory exclusion criteria, including age limits, should be avoided. This systematic review by Heesen et al. pits phenylephrine and noradrenaline against each other for the management of hypotension associated with spinal anaesthesia in women undergoing caesarean section. They found that noradrenaline may preserve haemodynamic stability to a better extent than phenylephrine. They also conclude that an effect of noradrenaline on the rate of fetal acidosis cannot be excluded, which could be due to the β‐stimulating properties of noradrenaline. However, they warn of a lack of data as these conclusions come from single trials only. It looks like this one is far from over!

Figure 1 Bubble plots for each surgical category showing the difference between the mean or median age of the randomised controlled trial population and the mean age of the equivalent populations in the English hospital registry, according to the middle year of study recruitment. Marker radius is proportional to the number of study participants.

Elsewhere this month, we have: a sub-analysis of pooled data from two prospective studies on 10 kHz spinal cord stimulation for the treatment of non-surgical refractory back painan analysis of patient and surgery factors associated with the incidence of failed and difficult intubation; and a randomised controlled trial of the effect of low-dose naloxone infusions on the incidence of respiratory depression after intrathecal morphine administration for major open hepatobiliary surgery. Over in Anaesthesia Reports, we have a report of airway obstruction during general anaesthesia in a patient with a vagal nerve stimulator. Make sure you send your reports today for an efficient and friendly peer review service, together with the chance to get a publication in a well-read PubMed listed publication!

Keep your eyes out for new about our next TweetChat, which we hope to bring to you very soon, and make sure you check out our complete free to access COVID-19 collection!

Mike Charlesworth and Andrew Klein