Author: theanaesthesia.blog

“The critical feature of all pandemics is uncertainty”

Coronavirus disease (COVID-19) literally needs no introduction. It arrived in China as an unwelcome New Year’s Eve present and although it may have taken a few weeks for many to become aware of it, it has become an ever-present in our lives since. It is, as we write, creating an epidemic across the world and is now sweeping across Europe. It is impacting everyday life in many ways and this impact is likely to become much more marked in the coming months.

Novel coronavirus

The single-strand RNA virus was named novel coronavirus 2019 (2019-nCoV), but due to its pulmonary consequences has been renamed as severe acute respiratory syndrome corona virus type 2 (SARS-CoV-2). It arises from mutation of a virus an animal reservoir, and origins from laboratory sources has been ruled out. It is related to the common cold virus and that causing severe acute respiratory syndrome (SARS) and middle east respiratory syndrome (MERS). Vaccines against these viruses are complex to develop, as illustrated by the fact we currently have no vaccine against the cold, SARS or MERS. The disease caused by SARs-CoV-2 is termed corona virus disease-19 (COVID-19) because the World Health Organization (WHO) was first notified of the localised surge in cases of pneumonia of unknown cause in Wuhan, China on 31 December 2019. 

The numbers

The world’s understanding of the disease owes much to massive international collaboration between scientists but most to the efforts of the Chinese clinicians and researchers collecting and making available data on the disease right from the start. The fundamental metrics as we currently understand them are shown in Table 1. As usual the numbers need to be well understood to tell the story.

R0	2–3 people
Ascertainment rate	10–25%
Attack rate	30–60%
Hospitalisation	12%
Symptoms
Mild	80%
Severe	15%
Critical	2–10%
Mortality	3.5%
Incubation	Up to 14 days
Most infective time	1–14 days

The R₀ describes the number of patients that a single patient will infect, in an uncontrolled setting. In the early stages of the epidemic it is believed that this figure may have been much higher, and R₀s tend to reduce during the evolution of an epidemic. Control measures such as isolation and quarantine reduce R₀. If these measures are effective, R₀ may be reduced to below 1 and if this is sustained the epidemic will eventually wane and stop. As long as the R₀ is >1, the epidemic will continue and there will be a geometric rise in cases. The impact of R₀ is important. Influenza has an R₀ of approximately 1.3: after 10 infective cycles this would lead to 14 infected patients from a single source. For SARS-CoV-2 after 10 infective cycles 59,000 patients would be infected. By comparison Ebola has an R₀ of around 2, SARS of approximately 3 and MERS ranged from 1 to 5.7 until finally it reduced to <1. 

Combined with this high R₀ is a high virulence, so while many cases cause mild disease the mortality rate is many fold higher than that of even pandemic influenza. Various figures for mortality have been quoted, but each is dependent on the numerator and denominator chosen. Of the first 100,000 confirmed cases approximately 3,400 died: thus, the case fatality rate (CFR) is 3.4%. However, it is likely that many cases, mostly because they cause asymptomatic or mild symptoms, are not detected. If this ‘ascertainment rate’ is only 10% this means 90% of cases are missed and the infected mortality risk (IFR) is 0.34%. But these figures only consider those who are infected, and the burden of disease in the population is also dependent on the proportion of the population who are infected (attack rate): many estimates are around 30%, but some as high as 60% or even 80%. If the attack rate is 30% and the IFR 0.34% the overall mortality rate would be close to 0.1% (1 in 1000 of the population). Lead-time bias (the fact that many patients will undergo several weeks of treatment before dying) complicates factors further and currently means that the initial 3.4% CFR is likely to be an underestimate.

However, illness and mortality are not spread evenly across the population. A remarkable epidemiological report from the Chinese Centre for Disease Control (CDC), published only a few days after data collection finished reported differential mortality rates by sex, age, comorbidity. 

Baseline characteristics	Confirmed cases; n (%)	Deaths; n (%)	Case fatality rate, %
Overall	44,672	1,023	2.3%
Age, years
0–9	416 (0.9%)	−	−
10–19	549 (1.2%)	1 (0.1%)	0.2%
20–29	3,619 (8.1%)	7 (0.7%)	0.2%
30–39	7,600 (17.0%)	18 (1.8%)	0.2%
40–49	8,571 (19.2%)	38 (3.7%)	0.4%
50–59	10,008 (22.4%)	130 (12.7%)	1.3%
60–69	8,583 (19.2%)	309 (30.2%)	3.6%
70–79	3,918 (8.8%)	312 (30.5%)	8.0%
≥80	1,408 (3.2%)	208 (20.3%)	14.8%
Sex
Male	22,981 (51.4%)	653 (63.8%)	2.8%
Female	21,691 (48.6%)	370 (36.2%)	1.7%
Comorbid condition†
Hypertension	2,683 (12.8%)	161 (39.7%)	6.0%
Diabetes	1,102 (5.3%)	80 (19.7%)	7.3%
Cardiovascular disease	873 (4.2%)	92 (22.7%)	10.5%
Chronic respiratory disease	511 (2.4%)	32 (7.9%)	6.3%
Cancer (any)	107 (0.5%)	6 (1.5%)	5.6%
None	15,536 (74.0%)	133 (32.8%)	0.9%
Missing	23,690 (53.0%)	617 (60.3%)	2.6%
Case severity§
Mild	36,160 (80.9%)	−	−
Severe	6,168 (13.8%)	−	−
Critical	2,087 (4.7%)	1,023 (100%)	49.0%
Missing	257 (0.6%)	−	−
Period (by date of onset)
Before Dec 31, 2019	104 (0.2%)	15 (1.5%)	14.4%
Jan 1–10, 2020	653 (1.5%)	102 (10.0%)	15.6%
Jan 11–20, 2020	5,417 (12.1%)	310 (30.3%)	5.7%
Jan 21–31, 2020	26,468 (59.2%)	494 (48.3%)	1.9%
After Feb 1, 2020	12,030 (26.9%)	102 (10.0%)	0.8%

Mortality is higher in males and particularly in those aged over 70 and with cardiovascular disease. This is most notably a disease that kills the elderly: patients aged over 70 represented fewer than 1 in 8 of those infected, but more than half of those who died. Deaths in those under 40 years-of-age account for < 3%. Early evidence outside of China is not reassuring and epidemiological patterns and mortality rates seem to be broadly in line with those from China.

The disease

The main feature of severe COVID-19 disease is a viral pneumonia. This presents as fever, cough and dyspnoea progressing to hypoxaemia and respiratory failure and ARDS. Importantly it often presents at least a week after symptoms start. Cardiovascular co-morbidity as a risk for mortality and evidence of hypertroponinaemia, myocarditis and sudden cardiovascular death are notable but incompletely characterised. Acute kidney injury affects up to a third of patients. 

Approximately 1 in 12 patients identified with the disease are hospitalised and 1 in 6 of these are critically ill. Of the critically ill approximately half require mechanical ventilation with more than half of these patients dying in most series.

What about the UK?

It is likely the epidemic will provide a daunting challenge to healthcare services for a period of approximately three months, a period we are just entering and which is likely to last until at least the end of May. The Chief Medical Officer estimates that 95% of cases will emerge over an 9-week period and 50% of cases in a 3-week period. 

The UK’s critical care capacity, which is one of the lowest in Europe, may need to be expanded at many-fold during this surge in demand. This will seriously challenge provision of the 4-Ss of surge capacity in critical care: space; staff; systems; and stuff (equipment). Expansion of critical care capacity requires planning on a massive scale. Critical care provision for COVID-19 patients will likely displace all elective surgical work as critical care units are expanded in many hospitals into operating theatres and anaesthetists and theatre staff become the first staff to augment the insufficient numbers of critical care staff. Emergency surgery will still be required as will provision of critical care for non-COVID-19 illnesses.

Central to care of these patients is staff safety. In the early stages, patients will need to be isolated from other patients and as the epidemic progresses, they will need to be cohorted away from non-infected patients. Staff protection will require a system that includes, but is not restricted to, strict use of personal protective equipment (PPE). Donning and doffing PPE, using a buddy system to ensure this is optimised and engaging in low patient contact methods will need to become second nature for all healthcare workers. Anaesthetists and intensivists are highly invested in this topic because airway management, including tracheal intubation, is associated with some of the highest risks of transmission of infection. PPE is likely to be effective, so too are simple methods of decontamination of surfaces, equipment and ourselves with soap and alcohol-based cleaning processes.

PPE is an emotive and important subject. In China, healthcare workers experienced high rates of infection in the early period of the epidemic, when PPE use may not have been optimal. Over time this rate of infection has reduced but it remains significant, and there is soft evidence from both China and Italy that healthcare workers who are infected have a higher rate of severe and critical illness than the normal population, plausibly because of exposure to a higher viral load. There are likely to be limited PPE stocks and appropriate use of it is essential to maintain stocks throughout the epidemic. 

What can we do?

If not already done, it is time to plan and time to act. Every hospital needs to plan its response to admission of its first patients with COVID-19 (phase 1 and 2), its first critically ill patient, and cohort of patients (phase 3). There is a pressing need for anaesthetists and intensivists to talk to each other, join forces and work together to organise and test the best response they are able. Collaboration in planning and delivery of critical care services in the predicted epidemic offers the greatest chance of weathering the storm. Given that the UK has half of the critical care beds per 100,000 capita of population than in Italy who have branched into the operating theatres already, there is a clear risk that our current resources will not suffice [8]. There will also be great strain on PPE supplies and medical, nursing and other workforces.

Hope

The numbers do however provide some hope. The spread of the disease beyond Hubei province in China is wide geographically but the number of cases and deaths is rapidly diminishing. The considerable efforts made by the Chinese government and people to control the epidemic appear to have worked and R₀ is now less than 1. On 8^th March there were no new cases reported in China outside Hubei. Drug trials are underway and will be reported soon, there may be therapies that reduce the severity of illness or help manage critically ill patients. 

In the meantime, it is going to be a very difficult period for frontline clinicians and all those we work with. Information and guidance changes often and rapidly. For anaesthetists and intensivists in the UK, a central source of information is likely to be a joint hub page run by all the key organisations who have joined together at this time for simplicity and clarity.

We encourage all readers to take stock at this time, get fit mask tests as a priority, familiarise themselves with their institutional PPE policies, practice and train for the management of COVID-19 patients, and agree robust local procedures for the likely epidemic to come.

Association of Anaesthetists members can also register for this free webinar update which takes place on the 14th of March from 0900-1100.

• 

• 

Professor Tim Cook and Dr Kariem El-Boghdadly

There has been recently an explosion of new regional anaesthesia techniques that seem to promise better outcomes for patients undergoing surgery. That said, most anaesthetists will probably never perform a PECS, QLB, BD-TAP, ACB, RLB, RISS, PENG, MICB or TQL block, to name but a few. Fear not, this excellent new editorial from Turbitt, Mariano and El-Boghdadly aims to recalibrate current practice and lists a limited selection of high value, basic blocks. You can hear more about this extremely popular paper, including why the authors wrote it and what they have planned for the future, in the next #TheAnaesthesiaPodcast on the 16^th of March. For now, readers might also be interested in this systematic review, meta-analysis and trial sequential analysis of the posterior suprascapular block in shoulder surgery and this meta-analysis of local anaesthetic delivery regimens for peripheral nerve catheters.

This new rapid sequence intubation survey from Zdravkovic et al. is impressive work for several reasons (Fig. 1). Firstly, they recruited over 10,000 anaesthetists from across the world using platforms such as LinkedIn. Secondly, they compared responses with the opinions of recognised international airway management experts. Finally, their results have consequences for clinical practice and a wide range of future research priorities. Will we ever achieve consensus for an area of practice with such wide variations and controversy? Charlesworth and El-Boghdadly argue such aims might be outdated, and the old questions about thiopentone vs. propofol, suxamethonium vs. rocuronium and opioid vs. no opioid are no longer relevant. Perhaps the new PUMA guidelines, expected later this year, will add some much-needed clarity. For now, readers might also be interested in this new multidisciplinary consensus statement on fasting before procedural sedation in adults and children, which we discussed recently in the #NotSoFast TweetChat. 

Figure 1 Preferences for rapid sequence intubation from respondents from high‐income countries (filled circles), upper middle‐income (diamond), lower middle‐income (triangle) and low‐income (empty circles). The upper three panels (a) are for a hypothetical patient with intestinal obstruction. The lower three panels (b) are for any other rapid sequence intubation indication.

Obstructive sleep apnoea (OSA) is common, with most cases in the peri-operative setting presenting without a formal diagnosis. This new prospective trial from Christensson et al. suggests that partial neuromuscular blockade in patients with OSA inhibits hypoxic ventilatory response, which is restored through full recovery from paralysis. The physiology behind this study and the methods used to investigate the hypothesis are simply fascinating! Thankfully, Raju and Pandit are at hand to explain all this along with the associated clinical context (Fig. 2). 

Figure 2 Schematic for oxygen sensing at type‐1 glomus cell of carotid body. (1) Hypoxia closes background K+ (TASK) channels, which normally permit background leak of K+ outside the cell; K+ is thus retained in the cell, causing depolarisation. (2) Depolarisation opens voltage‐gated Ca2+ channels, leading to Ca2+ influx. (3) This causes fusion of vesicles containing neurotransmitters (NT) with the cell membrane and acetylcholine (ACh; the likely clinically‐relevant neurotransmitter) is released into the synaptic cleft. (4) ACh binds to specific nicotinic receptors (nAChR) causing action potentials in the afferent glossopharyngeal neve, which travel to the respiratory centre. Volatile anaesthetics block the oxygen sensing by TASK channels at step (1). Propofol inhibits glomus cell response by an as yet undefined mechanism (possibly inhibiting voltage‐gated Ca2+ channels at (2); see reference 14). Neuromuscular blockade prevents binding of ACh at nAChR at (4).

Gastric ultrasound is becoming increasingly popular in the peri-operative setting, but it might also have a role in the critical care unit. This new prospective multicentre cohort study from Bouvet et al. suggests that gastric suctioning in mechanically ventilated patients is not a reliable tool for monitoring residual gastric volume. The question is, can gastric ultrasound be used in this setting to reduce the risk of regurgitation, vomiting and ventilator-associated pneumonia? Last year, we were delighted to publish our international consensus statement on the use of uterotonic agents during caesarean section. This highlighted the potential for a reduced dose of carbetocin of < 100 μg for low-risk women. This month, Drew et al. find that the ED₉₀ for carbetocin in obese women with a BMI ≥ 40 kg.m^-2 is less than this, and even less still for women with a BMI < 40 kg^-2 (Figure 3). Their methods are an excellent example of how a dose-finding study can be conducted using a biased coin up-and-down sequential randomised allocation scheme.

Figure 3 Sequence of doses administered and subsequent response. Success – filled circle; failure – open circle.

Elsewhere we have a study of the Quantra® point‐of‐care haemostasis analyser during urgent cardiac surgery; an observational study of the effects of tracheal intubation and tracheal tube position on regional lung ventilation; a study of the discrimination of quick Paediatric Early Warning Scores in the pre‐hospital setting; and a retrospective study of short‐term safety and effectiveness of sugammadex for surgical patients with end‐stage renal disease. 

Finally, we are delighted to announce that Anaesthesia Reports is now indexed on the PubMed database! Anaesthesia Reports represents the next generation of peer-reviewed journals that accepts case reports, videos, images and educational articles from authors anywhere in the world. Regardless of author background or subject area, it offers a cutting-edge platform for authors, readers and patients. PubMed listing is a major step forward, as it reflects the quality, legitimacy and scientific value of the journal. You can catch up with the most recent issue by reading this excellent summary from the editorial team.

• 

#ReportsComeOfAge!

• 

• 

Mike Charlesworth and Andrew Klein

Welcome to #TheAnaesthesiaBlog for the February 2020 issue of Anaesthesia, and with it comes the publication of a new guideline on safe transfer of the brain‐injured patient. Produced as a consensus document between the Association of Anaesthetists and the Neuro Anaesthesia and Critical Care Society, the guidelines serve to update the previous 2006 iteration. The document considers recent developments in the management of multiply-injured patients and those with acute ischaemic stroke. Whilst many of the principles of safe transfer are common to all seriously ill patients, specific risks and management strategies apply to those with acute brain injury. For example, the guideline provides new recommendations on the management of blood pressure parameters for common types of brain injury.

Table 1 Physiological variables and fluids for transfer of brain-injured patients. Of note, there is little high-quality evidence to support particular values and this table is the product of discussion and consensus between members of the Working Party. Where possible, the BP targets reflect the recommendations of the European Trauma Course.

The way in which we access information across all walks of life has changed beyond recognition over the last decade, and Johannsson and Selak discuss the implications of this for medical journals. Social media platforms are seemingly ubiquitous, and their use to disseminate new medical knowledge promises to increase the speed at which science is translated to improvements at the bedside.  Smartphones and other handheld digital devices are commonplace, with 65% of nurses reported to use mobile devices for work‐related tasks for at least 30 minutes each day. Unlike medical journals or conferences, accessing resources on social media platforms is usually free, always available and unrestricted by training budgets or work schedules. In the accompanying article, Ng et al. provide evidence that an intelligence‐led multimedia approach is an effective and efficient method to actively disseminate a clinical and educational patient safety message to a defined target audience. They produced videos to communicate recommendations from the safety project and Facebook, Twitter, YouTube and LinkedIn delivered these to their target users. There is now a need to think about measuring and comparing analytical outputs of social media such as reach, engagements, clicks and views, along with value for money.

Figure 1 Global social media activities relating to tracheostomies. A video of a three‐year‐old girl singing through her tracheostomy tube was posted on social media by her mother and was later reported by a newspaper (*). A television documentary about a synthetic organ surgeon, who was accused of falsifying his research on synthetic trachea transplantation, was broadcast (#). The news of a baby born without a nose dying at age two was posted on social media and was later reported by a multimedia news channel. He received a tracheostomy at five days old ($). An imprisoned Nobel Peace Prize laureate Liu Xiaobo’s was reported as being in a ‘life threatening’ state. His family opted against receiving a tracheostomy (^).

In other editorials, the motto adopted in 1945 by the Association of Anaesthetists, when granted the right to bear arms by King George VI, is called in to question as Ritchie-McLean and Davies discuss why patient safety training for UK doctors is inadequate. They put forward why they believe anaesthetists would benefit particularly from improved training, and how and when it should happen. The concept that fig leaves (in the guise of the words ‘pilot’ and ‘feasibility’) are used and attached to authors work to hide poorly conceived and conducted studies, is considered by Story in his editorial to accompany the review by Charlesworth et al. After hypothesising that only a small proportion of pilot or feasibility studies published in anaesthesia journals were correctly labelled as such, the authors show that only 34 of 266 (12.8%) pilot studies published in six anaesthesia journals between 2007 and 2017 were correctly labelled as such. Undoubtedly, these results have important consequences for patients, trialists, researchers and funders, and the authors argue that correctly labelled pilot studies enhance the quality of scientific research by encouraging methodological rigour, ensuring scientific validity and reducing research waste. 

Table 2 The difference between pilot/feasibility studies and non-pilot/non-feasibility studies as defined by the National Institute for Health Research and CONSORT guidance.

Finally, Oglesby, Sterne and Gibbison discuss the notion of using ‘big data’ to validate care bundles, consensus guidelines and protocolised care –  all of which have had a positive impact on patient care to date. In the related associated paper, Chiu et al. analysed over half a million sets of vital signs in 13,631 patients discharged from the cardiac intensive care unit to generate a logistic score. Comparisons were made between the national additive score and the composite outcome of: in‐hospital death; cardiac arrest; or unplanned intensive care admission. They conclude that a logistic version of the National Early Warning Score (NEWS), rather than the current additive model, better discriminates patients after cardiac surgery who suffer adverse outcomes following critical care discharge. Furthermore, logistic scores also provide a useful quantified tool of predicted risks for clinicians, which arguably NEWS cannot.

Figure 2 Black curves represent predicted probability of the physiological variable given the other predictors being controlled for logistic Early Warning Score (EWS). Horizontal red lines represent individual parameter dividing bins used by National EWS (NEWS, right axis).

Elsewhere (and not disguised with a fig leaf!), Webb et al. discuss their pilot study, which aimed to assess the feasibility and effectiveness of an offer of a free five-week supply of nicotine replacement patches provided to smokers at the time of listing for surgery, and to determine the effect on sustained abstinence for four weeks before surgery. Whilst the offer stimulated more cessation attempts before surgery, with many more in the intervention group either quitting or making attempts to quit, a large proportion (59%) had relapsed at six months.

Cricoid pressure has been a matter of debate since its introduction in 1961, and numerous studies have supported or contradicted its use. In this issue, Kim et al compared the effect of cricoid and paralaryngeal force on upper oeseophageal occlusion during induction of anaesthesia in a randomised crossover study involving 74 patients. Both cricoid and paralaryngeal force decreased the oesophageal inlet diameter, however, occlusion of the oesophageal entrance was more frequently observed with cricoid force application. As per recommended standards for monitoring during anaesthesia, a peripheral nerve stimulator should be used whenever neuromuscular blocking drugs are given during anaesthesia. That said, mechanomyography is seldom employed outside of the laboratory, and Bowdle find that acceleromyography and electromyography monitors are validated against such a device, with results consistent with previous comparative studies. Mechanisms underlying loss of consciousness following propofol administration remain incompletely understood. Sepúlveda et al. set out to study the pharmacodynamic effects of propofol through comparison of frontal lobe electroencephalography activity and brainstem reflexes during intravenous induction of general anaesthesia. Two independent mechanisms underlying the loss of consciousness have been postulated, and the authors demonstrate both to have a significant role depending on the rate of propofol infusion. 

For those of you with an interest in intensive care medicine and ultrasound, this new study from Dransart‐Rayé might be right up your street. Given that pulmonary complications have a significant impact on morbidity and mortality after major surgery, the authors conducted a prospective study in 109 patients to evaluate whether lung ultrasound could be used as a predictive marker for postoperative ventilatory support in high‐risk surgical patients. Using an easy‐to‐implement method, it was demonstrated that lung ultrasound abnormalities were indeed associated with postoperative pulmonary complications, and as such they conclude that the use of ultrasound could allow for earlier interventions and thus improve clinical outcomes.

Figure 3 Ability of lung ultrasound (LUS) score to predict requirement for postoperative ventilatory support (a) Receiver operating characteristic curve (b) inconclusive limits of LUS score (grey area).

Anaemia is an independent risk factor for poor peri‐operative outcomes after major intra‐abdominal surgery, and is associated with an increased risk of 30‐day postoperative mortality after non‐cardiac surgery. Miles et al. report data from 1554 women undergoing elective, major abdominal surgery stratified as a function of pre‐operative haemoglobin concentration. Borderline anaemia was associated with increased duration of hospital stay, fewer days alive and out of hospital, and an increased incidence of complications following major abdominal surgery. However, after correction for confounding factors the relationship between borderline anaemia and adverse outcomes was attenuated. 

Elsewhere, Jewer et al. report their findings of a Cochrane systematic review conducted on the effectiveness of supplemental intravenous crystalloid administration in preventing postoperative nausea and vomiting, Chae et al. discuss the development and validation of a dynamic predictive model for nausea and vomiting during the first 48 postoperative hours for patients receiving i.v. fentanyl PCA available as an online web application, and the Charlesworth and Shelton pose the question as to whether intravenous gelatins have a role in contemporary peri‐operative and critical care.

Finally, make sure you check out the first of our monthly podcasts, which will feature a key article from each issue. This month, Mike Charlesworth interviews Tanya Selak and Helgi Johannsson about all things social media, and how they collaborated on their work. Enjoy!

• 

• 

Dr Edward Gilbert-Kawai and Professor Andrew Klein

Welcome to our special issue for 2020, which is a unique collaboration between anaesthetists and surgeons. We begin with an editorial from the Editor-in-chief of Anaesthesia, Professor Andrew Klein, and the Editor-in-chief of BJS, Mr Jonothan Earnshaw, which features in both journals. They argue ‘it’s about time’, as surgeons and anaesthetists work together not only in the operating theatre, but also in delivering high-quality peri-operative care and research. We hope these special issues lead to more sharing of ideas, a desire for clinicians to read each other’s journals and more collaboration with all members of the multidisciplinary team for the good of patient care. This month’s blog focusses on the papers published in Anaesthesia, but we call on all readers to study carefully the contents of both supplements in both journals.

Fletcher and Engelman present a broad international perspective on who should care for patients after surgery. In order to tackle this question, one must first distinguish between different patient populations and surgical procedures. They suggest four themes which must be considered to improve postoperative care and patient outcomes, which appear throughout the issue (Fig. 1). Quinlan et al. tackle the problem of persistent postoperative opioid use, and the possible unintended consequences of fast-track surgery, scoring systems and patient satisfaction outcomes measures. Perhaps it is now time for more focus on procedure-specific pain management (including, where appropriate, regional anaesthesia), and an end to applying the World Health Organization’s pain ladder to the management of all pain in the peri-operative period. Levy et al. argue that restoration of function is the holy grail of peri-operative care. A big step on that journey is more collaboration between surgeons and anaesthetists, as well as developing systems for the early identification of patients who are at risk of not achieving restoration of normal homeostatic, physical and psychological function, including independence. 

Figure 1 Diagram of the key themes of postoperative outcome improvement. ICU, intensive care unit; HDU, high-dependency unit; ERAS, enhanced recovery after surgery.

Our first review is a global perspective of the quest for high-quality peri-operative care from Santhirapala et al. They argue that, in high-income nations, improvements come about through a focus on diagnostics, risk-scoring mechanisms and technology. For most of the world’s population, who do not live in high-income nations, these advances are of little relevance. We should, therefore, place more focus in the future on making high-quality peri-operative care equitable. This makes the paper from the African Peri-operative Research Group of vital relevance, and their top 10 priorities for peri-operative research are a must read for all.

The design of processes, equipment and environments to optimise peri-operative performance might be seen by some as ‘common sense’, but many advances in this field of healthcare have arisen from applying well-established principles from disciplines such as psychology, design and engineering. Marshal and Touzell argue it is now time to embed safety science experts within health organisations, as is the case in every other safety critical industry. It has been established previously that we have a natural tendency to overestimate rare risks and underestimate common ones. Wiles et al. find considerable variation in the numerical translation of verbal probability expressions by both patients and clinicians (Fig. 2). They suggest that verbal probability expressions should not be used as part of doctor-patient discussions regarding peri-operative risk. 

Figure 2 Box-and-whisker plots showing the numerical translation of verbal probability expressions by anaesthetists (white columns) and surgeons (grey checked columns). The solid line within the box represents the median, the limits of the box the interquartile range (IQR) and the whiskers represent the range. Outliers were defined as 1.5 9 IQR and are shown by ○.

Between 1999 and 2015, the number of patients aged over 75 years undergoing surgery nearly doubled. This state-of-the-art review discusses outcomes, risk assessment, risk modification, and pre-operative assessment of the older surgical patient. It seems there is now a need to redesign peri-operative pathways for older surgical patients to allow for shared decision making and personalised, evidence-based care. Enhanced postoperative recovery pathways have been continually redesigned and refined over the past 20 years. Kehlet present an overview of the associated key developments and discuss the challenges for the future (Fig. 3).  

Figure 3 Pathophysiological factors to consider for future improvement of enhanced postoperative recovery.

There is no clear consensus on which patients should be admitted pre-emptively to critical care following surgery. Unplanned postoperative critical care admissions are associated with poor outcomes, and this new systematic review from Onwochei et al. aims to describe risk factors for unplanned admission. Boyd-Carson et al. describe the surgical peri-operative factors to consider in emergency laparotomy care. The one factor that stands out is the influence of the national emergency laparotomy database in the UK, which has led to reduced mortality and length of stay. Foss and Kehlet describe the challenges in optimising recovery after emergency laparotomy (Fig. 4). They argue the case for procedure-specific enhanced recovery protocols for such patients, such as is normally seen for elective cases. 

Figure 4 Challenges in optimising pathways in emergency laparotomy.

Proponents of total intravenous anaesthesia (TIVA) cite the anti-oxidant, anti-inflammatory and immunomodulatory effects of propofol as compared with volatile inhalational anaesthesia. This new narrative review from Irwin et al. is a must read for all! They discuss effects on postoperative nausea and vomiting, free radical scavenging, organ protection, pain, and immunity. Will TIVA one day be the technique of choice for all patients undergoing general anaesthesia? Find out more by reading the free full text! Some of our most popular papers have described advances in regional anaesthesia. This review from Albrecht and Chin brings them all together for the first time. Find out all about advances in: safety and performance; fascial plane blocks; and extending block duration, as well as what the future might hold for regional anaesthesia. 

Acute kidney injury is a common complication in surgical patients and is associated with morbidity and mortality. Ostermann et al. describe the impact of surgery and anaesthesia on acute kidney injury, as well as the application of new biomarkers that may one day allow for a more personalised management approach (Fig. 5). Loop diuretics are commonly used in surgical patients with a positive fluid balance, but the impact of their use is uncertain. This new retrospective study of 14,896 critical ill postoperative non-cardiac surgical patients finds no association with overall mortality or the incidence of severe acute kidney injury. In fact, patients that received loop diuretics required a longer duration of postoperative mechanical ventilation. 

• 

Figure 5 Origin and function of different biomarkers for acute kidney injury.

Elsewhere we have reviews of: quality of recovery and long-term functional recovery after surgery; the role of patient-centred outcomes after hospital discharge; the importance of the postoperative recovery team; peri-operative cardiac biomarker screening; and an original article reporting a prospective observational study of the association between genome-wide polymorphisms and chronic postoperative pain. We hope you enjoy this year’s supplement, which is the most complete, accurate and up to date synthesis of evidence, consensus and expert opinion relevant to advances in peri-operative care. More importantly, we hope it contributes to more collaboration between surgeons and anaesthetists.

Join us over on Twitter as we discuss each paper from both journals in depth. See you later this week for #WSM2020! 

• 

• 

Dr Mike Charlesworth and Professor Andrew Klein

Welcome to the first issue of Anaesthesia for 2020, which is open access for all to read and download. Thankfully, modern anaesthesia is extremely safe, and reports of death due to anaesthetic-related complications are extremely rare. Some complications can be predicted, and it is sometimes even possible to employ strategies to mitigate the associated risk. This new paper from Ramalingam et al. prospectively examines the risk of transoesophageal echocardiography (TOE)-related complications in anaesthetised patients, and the results are alarming. Firstly, the incidence of complications was 1:1300, and the risk of death following a complication was ~40%, which is higher than previously thought. Secondly, complications occurred in patients without known risk factors. Ashworth and Greenhalgh provide some important commentary and context. It seems the benefits of peri-operative TOE continue to outweigh the risks for most cardiac surgical patients, but we can now provide patients with more precise estimates of the incidence of complications, which remain lower than the incidence of major surgical complications. One important recommendation is that insertion aids, such as a laryngoscope (or videolaryngoscope), are used. 

The prevalence of atrial fibrillation (AF) in general and peri-operative populations is increasing. This new secondary analysis of the VISION study finds that, in patients with a pre-operative history of AF undergoing non-cardiac surgery, postoperative cardiovascular events are more common than strokes. Interestingly, they also found that AF thrombo-embolic scores, such as CHADS₂-VAS_c better predicted these events than the revised cardiac risk index. In the accompanying editorial, Brand and Mackay describe the background to this secondary analysis and deliberate whether its findings will change clinical practice. Not just yet, it seems, but we might in the future use similar methods together with the VISION database to derive a peri-operative risk prediction model for all patients undergoing non-cardiac surgery. 

Figure 1 Receiver operating characteristic curves for each risk score and the primary outcome of any cardiovascular event (defined as myocardial injury after non‐cardiac surgery (MINS), heart failure, stroke, resuscitated cardiac arrest or cardiovascular death) within 30 days of surgery in patients with a history of atrial fibrillation. Revised cardiac risk index (c‐index 0.60) is denoted by the black line, CHADS2 (c‐index 0.62) is denoted by the blue line, CHA2DS2‐VASc (c‐index 0.63) denoted by the red line and R2CHADS2 (c‐index 0.65) denoted by the green line.

When caring for acutely unwell patients, the adage that a GCS ≤ 8 should be the threshold for tracheal intubation (for which there is little supportive evidence) seems to be increasingly irrelevant. That said, this new prospective cohort study of tracheal intubation practice variation in Europe after traumatic brain injury finds that GCS is the main driver of tracheal intubation for such patients. Like we recently saw with practices associated with rapid sequence intubation, there were substantial differences between countries and between centres. In the accompanying editorial, Lockey and Wilson argue that we should now aim to develop strategies to reduce this variation, and that the harm done by poor pre-hospital cannot be undone by in-hospital management for patients with traumatic brain injury. 

Figure 2 Proportion of pre‐hospital and in‐hospital patients who had their tracheas intubated across Europe.

Anaesthetists are thought to be at increased risk of suicide amongst the medical profession, as highlighted by an Association of Anaesthetists survey published earlier this year. These new guidelines are aimed specifically at anaesthetists, their departments and their employers. You can read the full paper here and access the infographic here. In our review section, we are delighted to publish a new network meta-analysis of the prevention of hypotension after spinal anaesthesia for caesarean section. The authors report that vasopressors are more efficacious than crystalloid infusions, with metaraminol the most effective. Phenylephrine was associated with more cases of maternal bradycardia. You can learn more about the theory and practice of network meta-analyses here. A further dimension to meta-analysis is the use of trial sequential analysis, the workings of which are described in this excellent editorial from Shah and Smith. 

Elsewhere this month, we have: a randomised controlled study of a new blood pressure monitor; a prospective study of patients declined emergency laparotomy; a quality improvement study of delirium after hip fracture surgery; a randomised controlled trial of the quadratus lumborum block for analgesia after caesarean section; and two excellent regional anaesthesia papers looking at needle tip tracking technology. Over in Anaesthesia Reports we have reports describing and discussing: hyperparathyroid-induced hypercalcaemic crisis with intracardiac thrombi; thrombolysis for submassive pulmonary embolism with left ventricular outflow tract obstruction; and laparoscopic hepatectomy in a patient with uncontrolled polycythaemia vera.

We hope you enjoyed our recent TweetChat on a new international multidisciplinary consensus statement on fasting before procedural sedation in adults and children (#NotSoFast). The associated discussion was fascinating, and you can see all the tweets by searching for the hashtag or clicking here. It has been an extremely busy month on social media, with high scoring papers including:  the new Difficult Airway Society awake tracheal intubation guidelines; guidelines for the transfer of the brain-injured patient; and a paper about pre-incisional hypotension and the association with postoperative acute kidney injury.

There is still time to register for the Association of Anaesthetists Winter Scientific Meeting in London, and our journal session will be on Friday the 10^th of January. Speakers include Dr Rosie Hogg, Dr Eric Albrecht and Dr John Carlisle. Finally, we will soon be publishing our 2020 supplement in collaboration with the British Journal of Surgery, which will cover all aspects of advances in peri-operative care. As ever, there will be a great blog, some useful infographics and lots of clinical take-home messages. 

See you in London!

• 

• 

Dr Mike Charlesworth and Professor Andrew Klein

This month, we are delighted to publish a national survey of out-of-hours working and fatigue in consultants in anaesthesia and paediatric intensive care medicine. There were nearly four thousand respondents and the majority had experienced work-related fatigue that impacts all areas of life (Fig. 1). For consultants, on-call duty often follows of a day of clinical work, and calls or requests to reattend hospital are common. There are several recommendations in areas such as: education; insight; job planning; rest periods; facilities provided by hospitals; and risk management. The accompanying editorial from Dawson and Thomas focusses on the identification and management of fatigue risk. They suggest solutions such as ‘more staff’ or ‘better rotas’ are unimplementable in the current UK healthcare environment, and we should instead focus efforts on strategies to measure and mitigate against the risks of fatigue. 

Figure 1 What impact do you believe that work‐related fatigue has had on your life in the following areas? From left to right, bars for proportion reporting significant negative impact (blue); moderate negative impact (orange); minimal negative impact (grey); no negative impact (yellow). (Answered by all respondents who had experienced work‐related fatigue, n = 3495)

The first logbook for anaesthetists was designed in 1983, and there now exists a variety of electronic means to record clinical activity. This new retrospective analysis from Perella et al., which is the largest of its type, brings together data from the log books of 964 anaesthetists over a 4-year period. Key findings include: a continued trend towards fewer case numbers over time; less supervision for trainees out-of-hours; appropriate exposure to basic procedures for trainees; and core trainees being supervised the most. Patients increasingly present for surgery with undiagnosed obstructive sleep apnoea, and there is an association with postoperative complications. This new observational study from Strutz et al. finds that obstructive sleep apnoea is not associated with the incidence of postoperative delirium or the severity of postoperative pain. The accompanying editorial from Memtsoudis supports this finding and highlights areas where the data provided by Strutz et al. add to what is currently an incomplete picture. We expect to see more on this topic in the future! 

It has been suggested that epidural injection of particulate corticosteroid is associated with greater pain relief as compared with non-particulate suspensions, but their use has been blamed for a small number of serious neurological complications. This new study finds that the dose administered is affected by injection filters, and that choice of diluent might be associated with the risk of serious complications due to a differential effect on particle size. Cheung argues patients should be fully informed about the possibility of catastrophic neurological damage with epidural steroid use. There is an urgent need for more research in this area, but, for now, clinicians must remain vigilant to the risk of these complications. This makes these articles essential reading for all clinicians performing these procedures.

Figure 2 (a) Mass spectra of TA+BP‐HCL before filtration with the (b) 5‐μm filter and (c) 0.2‐μm filter. Representative percentage abundance graphs are shown, and the characteristic m/z peak is highlighted in blue. (b) TA is clearly detectable in all samples before filtration with 5‐μm filter, but completely disappears as highlighted in red. (c) TA is clearly detectable in all samples before filtration with 0.2‐μm filter, but completely disappears as highlighted in red. TA, triamcinolone acetonide; BP‐HCL, bupivacaine hydrochloride.

Last year, Maheshwari et al. presented data highlighting the importance of identifying and managing hypotension following induction of anaesthesia and prior to the first surgical incision. This month, El-Ghazali and Pandit present an in-depth analysis of the methods used and the clinical implications of the conclusions drawn. One interpretation is that blood pressure measurements should be recorded and acted on every minute during this period, but a number needed to treat of over 400 makes this recommendation difficult to justify for all patients. Hypotension is just one consequence of general anaesthesia, and for some patients or procedures, the associated risks might be negated by using sedation. This new narrative review brings together the evidence for sedation-analgesia during cataract surgery, which is one of the most common operations performed worldwide. Most patients require no sedation (or fasting period) at all. The use of sedation and opioid analgesics in these patients should be no substitute for adequate local, topical or regional anaesthesia, as it significantly increases the risk of complications. 

Patients undergoing general anaesthesia are usually warned of the risk of dental trauma. This new manikin study finds that hyperangulated videolaryngoscopy is associated with significantly decreased forces acting on maxillary incisors, which may reduce the incidence of dental damage in the clinical setting (Fig. 3). Though one conclusion is it should be considered for all patients at increased risk of dental damage, some might instead argue it should be a first line technique for all patients. Many risks of anaesthesia and surgery can be addressed in the pre-operative period by patients. This new study looks at behaviour change before surgery among 301 patients from three UK hospitals. The results are positive, as patients demonstrated favourable attitudes towards changing single and multiple health behaviours, such as: low physical activity; an unhealthy BMI; and hazardous alcohol consumption. Smoking is a difficult area to address, and this is supported by the findings from a recently published (ahead of print) pilot study, which is now available on early view. Another important topic in this month’s issue is the need for peri-operative medicine to prioritise pregnant women. Dennis and Sheridan argue pregnant women are an integral peri-operative medicine population, and present the PARCEL approach to maternal peri-operative medicine. Perhaps it is now time to develop a core and extended outcome set for pregnant women undergoing caesarean section?

Figure 3 Anterior view anatomic mapping of peak resulting force on individual maxillary incisors of different laryngoscopy techniques in normal and difficult airway conditions.

Elsewhere this month we have: a retrospective impact study on the implementation of a hospital-wide Patient Blood Management monitoring and feedback programme; a randomised controlled trial of PECS 2 block vs. serratus plane block for chronic pain after mastectomy; a retrospective study of risk factors for children requiring adenotonsillectomy; and a consensus statement on the role of fibrinogen concentrate in cardiac surgery. Over in Anaesthesia Reports, there is an excellent account of peri-operative brachial plexus injury following self-positioning for stereotactic radiofrequency ablation. It reminds us that, despite all appropriate measures, patient injury is at times unavoidable.  

Finally, we will soon be publishing the new Difficult Airway Society awake tracheal intubation guidelines. These will be launched on Friday at the World Airway Management Meeting in Amsterdam, and there will be several ways in which you can get involved. We hope to see you there!

• 

• 

Dr Mike Charlesworth and Professor Andrew Klein

This month, we are delighted to publish papers on the design and evaluation of three novel devices aiming to address issues relevant to clinical practice. Firstly, Williams et al. have developed a syringe safety device to address the problem of syringe substitution errors. The device provides audio, visual and haptic feedback which supplements the visual cues provided by labelling, and can also help differentiate syringes containing vasoactive agents from other syringes. Darwood et al. have developed a simple, portable and potentially low-cost ventilator that uses a novel pressure-sensing approach and control algorithm (Fig 1). Both groups performed a series of successful benchtop experiments to test device performance, and studies evaluating clinical efficacy are now warranted. Batliner et al evaluated the performance of a novel flow-controlled syringe infusion pump at low flow rates against standard infusion syringe pumps in a laboratory study (Fig. 2). They found that the novel pump achieved a faster start-up to steady-state flow and more precise continuous drug delivery. The authors of all three studies should be commended on their efforts to develop solutions to important clinical problems. In the accompanying editorial, Peter Young discusses pathways to innovation and the issues that clinicians face when developing such devices, especially with regard to patents and intellectual property.

Figure 1 Unpacked test rig prototype: (a) motor and impeller; (b) pressure‐sensitive mechanical switch; (c) patient connection; (d) exhaust valve; (e) external pressure sensor (for experimental purposes); and (f) control board and microcontroller.

Figure 2 Functional principle of the flow‐controlled syringe infusion pump. Top: Picture of prototype flow‐controlled syringe pump. Bottom: Schematic principle of flow‐controlled syringe infusion pump. This system has a spring load mechanism (1) arranged to press against the plunger (2) of a disposable plastic syringe (3). The system is equipped with a real‐time flow rate sensor (4) and a pinch valve (5) to control the flow of the liquid by restricting the tube. The controller takes the flow rate as input to control the pinch valve.

We have recently published a series of articles related to fatigue, burnout and wellbeing amongst anaesthetists. This month, Yentis et al. present the results of a survey investigating the experiences of anaesthetists related to the suicide of colleagues. The results are sobering. Of the 3638 responses received, nearly 40% had first-hand experience of a colleague’s suicide. Almost a third of respondents with experience of suicide reported more than one case. Most reported cases involved administration of commonly used anaesthetic drugs and occurred within the last 10 years. The vast majority of suicides occurred in doctors aged in their 30s and 40s. From an organisational perspective, nearly a quarter of suicide reports were deemed to be work-related. Many respondents were unaware of departmental or hospital policies on mental health, addiction or welfare. 

Potential solutions include: increasing awareness and support of mental health issues at work; developing local guidelines and pathways for managing work-related stress and substance abuse; and tighter control and accountability of access to anaesthetic drugs. In the accompanying editorial, David Scott discusses the impact of suicide on second victims. These are family members, friends and work colleagues of the victim, and there is often little or no support available to them. In addition to building supportive infrastructures, our focus should also be on the prevention of suicide. 

Aluminium release from fluid warming systems continues to generate interest. Taylor et al. found a significant uptake of aluminium into Plasma-Lyte 148 and compound sodium lactate fluids administered via an uncoated fluid warmer (Fig. 3).Lower levels were observed with blood product infusions but were still greater than the US Food and Drug Administration recommended levels. This study further validates the original findings by Perl et al. reported earlier this year. Using the example of excessive aluminium release being reported from uncoated fluid warming devices, McGuire et al. describe the processes by which the MHRA assessed the risk and implemented action to protect patients.

Figure 3 Mean aluminium concentration in three commonly used crystalloid solutions (● 0.9% saline; ♦compound sodium lactate ■Plasma‐Lyte 148) when run through an enFlow fluid warmer at 2 ml.min^-1. Each datum point is the mean of two to five measurements (SD not displayed for clarity). “0 min” represents a room temperature baseline sample before attachment of the enFlow device. The US Food and Drug Administration maximal permitted aluminium level in i.v. nutrition is 25 μg.l^-1 (0.9 μmol.l^-1).

We have three articles in this month’s issue related to regional anaesthesia. Lyngeraa et al. investigated the analgesic effects of an adductor canal block using catheter-based boluses, either through a new suture-method catheter or a standard perineural catheter, compared with a single injection technique in patients undergoing total knee arthroplasty under spinal anaesthesia. They observed no difference in pain scores or opioid consumption between the study groups. However, muscle strength and ambulation on postoperative day 2 were better in the catheter-based bolus group irrespective of the type of catheter. Rao Kadam et al. demonstrated a marginal postoperative analgesic benefit of a transmuscular quadratus lumborum block compared with a surgical pre-peritoneal catheter in patients undergoing elective abdominal surgery. This marginal benefit should be balanced against the financial cost of a quadratus lumborum, which is $575 AUD more per patient. In a mechanistic study, Holmberg et al. used laser Doppler fluxmetry and capillary video microscopy to assess microcirculatory and nutritive blood flow following the addition of adrenaline to lidocaine in health volunteers undergoing infraclavicular brachial plexus blocks. The authors found that the addition of adrenaline reduces nutritive blood flow, but produces stronger and longer lasting blocks (Fig. 4).

Figure 4 Changes in nutritive blood flow: picture (a) shows functional capillary density between the first and second metacarpal on the dorsal side of the hand before infraclavicular block. Picture (b) shows functional capillary density in the same place in the same patient 30 min after infraclavicular block with adrenaline.

Gender imbalance is an important issue that requires addressing, particularly in academic medicine. Only 29% of UK professors in medicine are female, and anaesthesia has one of the lowest proportions of female professors (8%). In addition, only 25% of first authors in prominent science journals such as Nature and Science were female. A similar proportion has also been identified in anaesthetic journals (Fig. 5) .Laycock and Bailey investigated whether this also holds true for case reports submitted to Anaesthesia Cases. They hypothesised that such an imbalance may not present in more clinically-orientated publications, particularly as the proportion of female anaesthetic consultants and trainees is rising. Using an overall sample of 786 submissions over a 4.5-year period, they found that the proportion of female first authors of accepted case reports was 112/266 (42.1%). Importantly females were first authors in only 172/500 (34.4%) of rejected case reports. In view of these reassuring and positive findings, the authors make a strong call for tackling equity at all levels from medical school applications, through research funding, journals and editorial boards.

Figure 5 Proportion of female first authors in four anaesthesia journals. AC, Anaesthesia Cases; BJA, British Journal of Anaesthesia; Anesth, Anesthesiology; A&A, Anesthesia and Analgesia

Elsewhere, Charlesworth and van Zundert review the use of electronic health records and explore the possibility they may one day replace national anaesthesia databases. They highlight the ‘My Health Record’ initiative currently being implemented by the Australian government. There are clear advantages to such initiatives, such as easy access to high quality information, but this has to be balanced against concerns such as data privacy and the impact on current working practices. 

In our reviews section, Sharawi et al. conducted a systematic review to evaluate the quality of patient reported outcome measures (PROMs) to assess functional recovery following caesarean section. They used a COSMIN appraisal checklist to evaluate quality. They identified 13 PROMS but only one – the ‘Obstetric Quality of Recovery-11’, achieved the high COSMIN standards for any PROM. Kumar et al. provide insights into pharmacogenomics and ongoing pharmacogenetic research relevant to opioid drugs. They highlight the role single-nucleotide polymorphisms play in the variability we observe with the use of opioids in our daily clinical practice. Further research into such genetic factors will have an important role for personalised medicine in the future. This review is a must read. 

Over in Anaesthesia Reports, Ireland et al report the use of a sacral plexus catheter for continuous local anaesthetic infiltration in a patient who sustained a unilateral sacral ala fracture following a fall from a horse. The catheter was successfully inserted under ultrasound guidance and resulted in satisfactory patient analgesia, mobilisation and chest physiotherapy. Finally, our next TweetChat will focus on a new paper from Marko Zdravković and colleagues, which is a large international survey on practices associated with rapid sequence intubation (#RapidSequence). This will take place at 1900 GMT on the 31^stof October. You heard it here first!

• 

• 

Dr Akshay Shah and Professor Andrew Klein