Understanding peri-operative risk

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-VASc 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 patientsLike 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 yearThese 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 monitora prospective study of patients declined emergency laparotomya quality improvement study of delirium after hip fracture surgerya 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 thrombithrombolysis 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 guidelinesguidelines 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 10th 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

Fatigue in the workplace – a ‘wicked problem’?

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 painThe 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 sizeCheung 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 programmea randomised controlled trial of PECS 2 block vs. serratus plane block for chronic pain after mastectomya 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 Reportsthere 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

Innovation in anaesthesia

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 fatigueburnout 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 ReportsIreland 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 31stof October. You heard it here first!

Dr Akshay Shah and Professor Andrew Klein

Burning the candle

This month, we are delighted to publish two studies from the SWeAT study investigator group. The first is a quantitative analysis of survey responses from 397 UK anaesthetic trainees on the safety and wellbeing of these doctors and the patients they treat. They conclude that stress, burnout risk, depression risk and low work satisfaction are common. Interestingly, negative psychological outcomes might be independently predicted by having: no children; more than three days of sickness in the previous year; less than one hour of exercise per week; and more than 7.5 hours per week additional non-clinical work. The qualitative paper focusses on themes from interviews with ten trainees, of whom most were in the higher risk group for burnout and depression. Suggestions include: contracted hours for non-clinical work; individuals taking responsibility for self-care; cultural acceptance that doctors can struggle; and embedding wellbeing support more deeply. 

Figure 1 Euler diagram displaying the proportion of all respondents categorised with high perceived stress, high burnout risk and high depression risk, and the co‐existence of these issues.

Brian Jenkins discusses fatigue vs. resilience and what can be done. Decreasing on-call requirements might be one suggestion, but this has important implications for training. Good role models are important, as is recognition of the process by which resilience is taught and learned throughout training. McCrossan et al. argue that looking after our own and our colleagues wellbeing should be a core element of training. Perhaps it is now time to increase the availability of mentoring, but, for this to happen, we need to train more mentors and have a better collective understanding of what mentoring is. 

In July, we published the first international consensus statement on the use of uterotonic agents during caesarean section. The paper was a success on social media and currently holds an Altmetric score of over 200. Doses of oxytocin for routine elective caesarean section are lower than in other guidelines, and higher doses are recommended for women at increased risk of postpartum haemorrhage. Monks and Palanisamy highlight some issues with the quality of literature on which the consensus statement is based. They offer the pragmatic suggestion that we should use the smallest possible dose of oxytocin in combination with proper stewardship. Perhaps future research should focus on the longer-term consequences of this potent neuropeptide. 

Is it safe to give propofol to those with allergies to egg? It’s time to answer the question once and for all, at least in children. Somerfield et al. identified 2608 children with a clinical food allergy, of which 304 were exposed to propofol. There were 13 potential reactions in ten children. One was deemed a probable allergy and it could not be excluded in another. Both reactions were non-severe. They conclude that, overall, propofol was safely administered to children with allergies to egg, peanut, soybean or other legumes. Anderson and Sinclair discuss allergy vs. sensitivity with specific examples. They argue the study by Somerfield et al. supports current consensus, and that the main risk factor for a peri-operative anaphylactic event is a previous history of a peri-operative reaction.

We already know that airway management research sometimes fails to address commonly used techniques in clinically relevant patient populations. This month, Lundstrøm et al. report data on the DIFFMASK score for predicting difficult facemask ventilation. They study 48,804 patient records and report a prevalence of difficult facemask ventilation of 1.1%. Age, increased BMI, the presence of a beard and neck radiation changes were identified as risk factors. In the accompanying editorial, El-Boghdadly and Aziz discuss the limitations of this evidence and on approaches that are known to improve FMV conditions, such as utilising neuromuscular blockade and optimising the patient’s position

Figure 2 a) Possible sequences of events relating to face‐mask ventilation (FMV) during anaesthetic induction with a traditional approach. There are three broad phases after induction, delineated by colour‐coded boxes: first check of FMV; then a choice of three options depending upon the ability to mask ventilate (neuromuscular blocking drug (NMBD)/immediate choice); then several consequences of those choices. Note that waking a patient up after difficult FMV (dashed red line) is rarely done, and administration of a long‐acting NMBD after difficult FMV was thought to be dangerous (dotted red line). Waking patients up in the third phase is only possible if suxamethonium is given. Green lines indicate successful outcomes, red lines indicate unsuccessful outcomes. Redrawn from 13 with permission. (b) Possible sequences of events relating to FMV during anaesthetic induction with an approach based on recent data. There are three broad phases after induction, delineated by colour‐coded boxes: administration of a long‐acting NMBD before checking FMV; then FMV; then the consequences, which could be either tracheal intubation, or if unsuccessful, the failed intubation algorithm.

Despite the existence of many guidelines for postoperative pain management, we do not always get it right for all patients and all procedures. This month, we describe the methods used for the development of evidence-based recommendations for procedure-specific pain management: PROSPECT methodologyThe first PROSPECT paper focusses on rotator cuff repair surgery, and recommendations include: an arthroscopic approach; systemic multimodal analgesia; interscalene brachial plexus blockade; i.v. dexamethasone; and opioids reserved for rescue analgesia. We look forward to seeing further articles describing specific approaches for other procedures. Elsewhere, we have: a study of postoperative delirium screeninga randomised controlled trial of the PECS-2 block for radical mastectomya prospective cohort study of extravascular lung water measurement in patients undergoing pulmonary endarterectomy; and the educational impact of the SAFE® paediatric anaesthesia course.

Over in Anaesthesia Reportswe have a description of three ventilatory techniques to maintain oxygenation in a patient undergoing laser tracheal tumour resection and a report of McArdle disease causing rhabdomyolysis following vaginal delivery. You can now comment on any of our articles using our new DISQUS function. Click on the comment button next to an article or go straight to the comment box at the end of the article. If you write an interesting comment, we will ask you to consider submitting it as a formal letter for publication.

Finally, we have all now returned from an excellent trip to Glasgow where we announced our 4th annual article of the year. Kariem El-Boghdadly simply blew the audience away with his presentation, which was streamed on multiple platforms and with all winners announced in real time on Twitter. You can watch his presentation here. The author of our winning article, Marcelle Crowther, flew in to collect her award from South Africa, along with her parents. Her paper is free forever and supports recommendations from the Joint Guidelines from the Association of Anaesthetists and the British Hypertension Society. Her colleagues from the department of anaesthesia and peri-operative medicine at the University of Cape Town watched her receive the award, and we watched them watch us. According to Nick Chrimes, we were all well and truly sucked into the vortex.

Dr Mike Charlesworth and Professor Andrew Klein

Smile for the camera!

Audio-visual recordings of doctor-patient interactions might have the potential to improve the consent process. Ivermee and Yentis report on the attitudes of postnatal women, anaesthetists, obstetricians and midwives towards audio recording of consent discussions. Most participants found the idea acceptable, yet some staff had concerns about confidentiality, technical difficulties, and the possible detrimental effects on the doctor-patient relationship and consent process. These concerns were not shared by most postnatal women. Combeer and Iqbal make a case for embracing such opportunities to improve patient care, and provide a balanced account on the pros and cons of audiovisual recordings of patient care. Such recordings are likely to become more common and our engagement is required to ensure this leads to positive outcomes for patients and anaesthetists.

Good quality antenatal information provision is a vital part of preparation for labour. Brinkler et al. surveyed 903 postnatal women across 28 London hospitals on the provision of anaesthetic and analgesic information during pregnancy and delivery. Concerningly, only 9% and 12.1% of women recalled receiving antenatal information covering all aspects of labour analgesia and caesarean section, respectively. Only 68.7% felt confident about their analgesic choices as a result. The authors call for better ways to deliver information to expectant mothers and this might require more collaborative ways of working.

Maternal satisfaction with anaesthetic care is a complex metric. Yurashevich et al. evaluated data from 4297 postpartum women to establish determinants of dissatisfaction with anaesthesia care in labour and delivery. Factors associated with maternal dissatisfaction following vaginal delivery included: pain intensity during the first and second stages of labour; postpartum pain intensity; delays of more than 15 minutes in providing epidural analgesia; and postpartum headache. Postpartum pain, headache and pruritus were associated with dissatisfaction after caesarean delivery. These findings reinforce the contribution of the anaesthetist to a positive birth experience, which might be improved by more rapid responses to epidural analgesia requests and by contributing more to postoperative pain management. 

The first international consensus statement on the use of uterotonic agents during caesarean section has now been published on Early View. This was our top paper on social media in July, with an Altmetric score of 225! It is essential reading for all obstetric anaesthetists and obstetricians, and it may also be useful to those sitting the FRCA exam. 

Haemostatic activation during cardiopulmonary bypass may lead to coagulopathy, or paradoxically, postoperative thromboembolic complications. Ho et al. evaluated the association between platelet dysfunction and adverse outcomes in cardiac surgical patients. They found that for every 1% increase in platelet dysfunction during the rewarming phase of cardiopulmonary bypass, there was an 1% increase in the incidence of adverse postoperative events. This was a secondary analysis of data obtained from the transfusion avoidance in cardiac surgery trial – which was a stepped-wedge, cluster randomised controlled trial. In the accompanying editorial, Charlesworth and Agarwal succinctly describe the basics of a stepped-wedge cluster design and discuss how the authors recycled an old dataset to answer a new research question. Importantly, they stress that the study by Ho et al. is not ‘salami sliced’ – an issue that Anaesthesia has a clear stance on

Figure 1 A schematic of a simple five cluster study conducted over six months. Clusters can be, for example, collections of different wards, theatres, hospitals or sites. Each month (or day, week or year), one cluster is randomised to cross over from control (black) to intervention (green). At the end of the trial, all participants are receiving the intervention.

Unplanned admission to critical care is associated with poor patient outcomes and increasingly used as a performance metric. Shelley et al. report on the association between anaesthetic technique and unplanned critical care admission after thoracic lung resection surgery. Their multicentre retrospective audit includes 11,208 patients undergoing lung resection surgery in 16 NHS thoracic surgical centres between 2013 and 2014. The most striking finding was that patients receiving total intravenous anaesthesia or thoracic epidural analgesia were less likely to have an unplanned admission to critical care. Licker remind us that these findings should be interpreted with caution for several reasons, and the conclusions drawn have already sparked much debate on Twitter. However, these findings are certainly hypothesis generating and should pave the way for well-designed prospective studies.

Current DAS guidelines recommend a scalpel-based technique as first-line for an emergency front of neck airway, but prospective data to support this are lacking. The recent study by Rees et al., which was recently featured in the popular #FrontOfNeck TweetChat, challenge these recommendations. DAS guidelines are only one of 38 published airway management algorithms, as highlighted in a directed review comparing and describing all difficult airway management algorithms published over the past 20 years. Whilst the frequency of algorithm publication has increased, many are overwhelmingly similar and data on implementation and outcomes are limited. An endorsed universal single airway algorithm is needed. Watch this space! 

Figure 2 Algorithm publication frequency from 1998 to 2018 with the number of publications per year (blue bars) and the number of cumulative algorithms published (orange bars).

Elsewhere, Jelacic et al. introduced an aviation-style computerised pre-induction checklist, as part of a quality improvement project, and demonstrated a reduction in the number of failures to perform all pre-induction stepsCarvalho et al. found that pre-operative voice evaluation of vowel phenomes has the potential to predict a difficult laryngoscopy. This is a novel finding and its potential incorporation in current airway assessment strategies requires further investigation. Crewdson et al., in a retrospective analysis of the Trauma Audit Research Network database, evaluated emergency airway interventions for patients admitted to major trauma centre. Over 70% of emergency department tracheal intubations were performed within 30 minutes of arrival. Worryingly, patients who required pre-hospital airway support and did not receive it had a higher mortality. This work suggests an unmet need for pre-hospital advanced airway management. Also, Lukannek et al. report on the development and validation of the Score for the Prediction of Postoperative Respiratory Complications (SPORC‐2) to predict the requirement for early postoperative tracheal re‐intubation.

Figure 3 Modifications made to the Anesthesia Patient Safety Foundation (APSF) pre‐anaesthetic induction patient safety checklist to create computerised version used for this study. The APSF pre‐anaesthetic induction patient safety checklist is shown on the left (a). A screenshot of the computerised pre‐induction anaesthesia checklist is shown on the right (b). Functionality of Checklist Navigator includes a checklist pull down menu, ‘Remote Display’ button, a case information window, ‘Reset Checklist’, ‘Close’, ‘Skip’ and ‘Undo’ button.

Promoting sustainable healthcare to medical practice has recently been recognised as an essential element of undergraduate medical education by the General Medical Council. Anaesthetists have been at the forefront of reducing the environmental impact of healthcare, and Shelton and White provide guidance on the leading role anaesthetists can play in developing and teaching this element of the undergraduate curriculum. They advocate a model from the Centre for Sustainable Healthcare which reduces environmental impact without adversely affecting health.

Figure 4 Driver diagram of the Centre for Sustainable Healthcare principles of sustainable clinical practice.

In our latest ‘Clinical Consequences’, Shah and Carlisle discuss and review the evidence supporting the use of cuffed tracheal tubes in paediatric anaesthesia. An updated meta-analysis shows they were changed one-sixth as often as uncuffed tubes. Sore throat was also less common with cuffed tubes, and the rates of laryngospasm and stridor were similar. Over in Anaesthesia Reports, an editorial from Dalay et al. summarises all the key learning points from the first issue, and Watton et al. report a case series of midpoint transverse process to pleura catheter placement for postoperative analgesia following video‐assisted thoracoscopic surgery.

Finally, we are looking forward to seeing everyone at Annual Congress in Glasgow next month. The Anaesthesia journal session takes place on Friday morning and Kariem El-Boghdadly will present the Anaesthesia article of the year. We look forward to finding out who made it into this year’s #AnaesTop10.

See you in Glasgow!

Dr Akshay Shah and Professor Andrew Klein

Future directions for obstetric major haemorrhage

Summer has arrived and we are back from an excellent 2019 Trainee Conference in Telford. Highlights included: a keynote lecture from Professor Colin Melville on the General Medical Council and training; a talk on awake breast surgery from Amit Pawa; a debate on the role of social media in the medical profession; and a conference dinner and dance under the planes at RAF Cosford.

This month, Sullivan and Ralph present the results from a single centre retrospective cohort study evaluating the use of intra-operative cell salvage in 6352 obstetric patients. Between 2008 and 2017, cell salvage was used routinely for 98% of caesarean deliveries at the authors’ institution. They found a reduction in blood transfusion rates during the study period, whilst also demonstrating that routine cell salvage seems to be safe and economical. These results contrast with the SALVO randomised controlled trial which found no evidence of benefit with cell salvage. Wong and Toledo eloquently discuss the differences between observational studies and randomised controlled trials, which is always a hot topic on Twitter. They suggest further research is necessary before completely condemning the routine use of cell salvage, which is possibly at odds with the recent Association of Anaesthetists cell salvage guidelines

Point-of-care viscoelastic haemostatic assays are becoming increasingly popular. McNamara et al. present four years of prospective data following the introduction of a ROTEM algorithm for the treatment of coagulopathy in major obstetric haemorrhage (Fig. 1). They found a reduction in the use of blood products and the number of patients with transfusion associated circulatory overload. Most women experiencing haemorrhage did not have any evidence of coagulopathy, except in cases of placental abruption. Shah and Collis therefore ask, should we abandon the use of fixed ratio blood products in obstetrics, and should hypofibrinogenaemia be treated with cryoprecipitate or fibrinogen concentrate? These questions aside, knowledge of early haemostatic competence does have the potential to influence clinical management. If early results are normal, the focus can shift towards surgical causes of bleeding and allogeneic transfusions may be avoided. This is perhaps where the true benefit of using these new assays lies in the context of obstetric practice.

Figure 1 Number of units of blood and blood products per patient.

The use of dexamethasone as an adjunct to peripheral or central neuraxial blockade is controversial. Albrecht et al. report their randomised, triple-blind study to evaluate the effect of increasing doses of perineural dexamethasone on analgesia duration in patients requiring an interscalene brachial plexus block. They observed that perineural dexamethasone, with doses ranging between 1-4 mg, prolongs the duration of analgesia in a dose-dependent manner. Heeseen et al. undertook a meta-analysis to investigate the effect of intravenous dexamethasone on postoperative analgesia when given after spinal anaesthesia. They observed a significant reduction in 24-hour morphine consumption and significantly longer time to first analgesia request in the dexamethasone group as compared with the control group. Marhofer and Hopkins argue that, although there is no evidence that dexamethasone for regional anaesthesia causes harm, there are many good reasons why the evidential bar for a clinical benefit has not been met, yet.

Medication errors in peri-operative practice are commonSivia and Pandit have developed a new mathematical model to predict drug errors, which also incorporates the effect of operator fatigue. They observed that ~10% of operations lasting ~12 hours will result in a drug error, which is unacceptably high but consistent with other studies. Risks may be mitigated by anaesthetists recognising contributory factors such as illness, fatigue and working in unfamiliar environments. There have been many calls to move beyond labelling such problems as ‘human error’ and instead focus on continuously engineering human-centred safety systems. Carlisle and Merry discuss the science of reducing failure, and the possible applications and limitations of this new model. Time will tell us whether the safety of anaesthesia will improve as a result.

Figure 2 Modelling the probability of error over the course of an operation in which there are five drugs and tree possible routes for injection for three intrinsic error rates of 0.1% (green), 1% (blue) and 10% (red). The same result obtains for a scenario of three drugs and five possible routes for injection.

Excessive ambient noise in the critical care environment is a common patient compliant and can have negative sequalae. To address this problem, we must first isolate the source of the noise. Darbyshire et al. mapped the source of noise on a critical care unit and observed most loud sounds originated from very limited areas that were very close to patients’ ears. These noises may originate from bedside equipment and monitoring alarms, and simple redesign measures may be an effective way to reduce this environmental noise burden (Fig. 3).

Figure 3 Heat map which can be interpreted as average ‘noisiness’ map for the ICU bay. ‘Hotter’ colours (reds and yellows) indicate areas where loud noises are more frequent. The area of noise marked ‘1’ is outside the side room that was preferentially used, and shows where conversations between staff about the patient in the side room commonly took place. The areas of noise marked ‘2’ correspond to the positions of the telephones.

Bertaggia question the evidence we use to inform peri-operative practice through calculating the Fragility Index of all peri-operative randomised controlled trials reporting a significant effect of an intervention on mortality. They found that, for most trials, the significance of interventions was sensitive to only a few more deaths amongst participants. They suggest trialists should consider reporting the Fragility Index with studies, which is the number of participants without events who would have to experience events to increase p to ≥ 0.05. We look forward to inevitable debate over on Twitter! The first issue of Anaesthesia Reports has now been published! Recent reports include critical illness following topical application of a skin-lightening preparationmajor haemorrhage following vascular injury during exchange of cardiac pacemaker leadspre-operative ventricular bigeminy and cardiomyopathy; and critical illness in a patient with influenza A and sick cell trait.

Elsewhere, Weatherall compare portable blood warming devices under simulated pre-hospital conditions; Ki et al. find that a new EEG monitoring system (phase lag entropy) might be a useful hypnotic depth indicator in patients receiving propofol sedationKotoda et al. compare different methods of rigid stylet removal to minimise adverse force and tracheal tube movement; and Bojesen find that hypoxaemia after surgery for colorectal cancer is perhaps much more common than we might expect.

We recently issued two press releases for important articles with implications for anaesthetists, departments and hospitals. You can read all about peri-operative transoesophageal echocardiography-related complications and the Association of Anaesthetists survey on suicide amongst anaesthetists over on early view. Both articles are free forever. Finally, we are delighted to announce that our 2019 Impact Factor has increased by 8% to 5.9, according to the yearly Journal Citation Reports just published by Clarivate. Our journal is ranked 4th out of 31 in the category “Anesthesiology” and was the only journal in the top four to increase its Impact Factor in this year’s Report.

#onwardsandupwards

Professor Andrew Klein and Dr Akshay Shah

Getting it right first time

This month, in a stinging editorial, Professor Pandit argues a lack of rational data on theatre performance and efficiency make the NHSI report on operating theatres an almost worthless read. It is perhaps the claim that list over-runs are due to late starts or gaps between cases that will strike a chord with clinicians. He argues such claims are not backed by evidence and are at odds with existing literature. This editorial is a must read for all theatre staff and you can read a response from one of the report’s authors here.

Tranexamic acid has revolutionised the management of traumatic and non-traumatic haemorrhage following the publication of the landmark CRASH-2 and WOMAN trials. Whilst the peri-operative benefits of tranexamic acid are well documented, Patel et al. provide data on catastrophic drug errors that have arisen as a result of intrathecal administration. They identified 21 cases with a mortality rate of just under 50% (10 out of 21 cases). Of the remaining 11 cases, 10 required ICU admission for refractory convulsions and/or tachyarrhythmias with a high incidence of permanent neurological injury in survivors. Perhaps the most worrying (and disappointing) finding is that an ampoule error (i.e. not checking or reading the label, similar size ampoules) occurred in 20 patients. This is unsurprising, given the similarities shown in Figure 1In the accompanying editorial, Palanisamy and Kinsella discuss potential causes of such errors and provide practically useful solutions to reduce the risk of such rare, but catastrophic errors, down to zero

Figure 1. Similarity of tranexamic acid and bupivacaine ampoules.

Gastric ultrasound is becoming increasingly popular. Studies so far have used a variety of different participant positions to evaluate gastric volume using ultrasound, and the ideal position is unknown. Bouvet et al. address this by evaluating the effect of different patient positions and different bed angles on gastric ultrasound contents in healthy volunteers. They found the angle of the bed can significantly affect ultrasound performance, and a 45°angle performed the best to detect gastric fluid volume > 1.5 ml.kg-1. Nascimento et al., in a non-inferiority randomised trial of labouring women, observed that maltodextrin was cleared from the stomach faster than coffee with milk and orange juice. These studies add to the growing body of evidence suggesting gastric emptying and volume are not solely dependent on volume ingested and total calories, but also on other factors such as protein and lipid content and patient positioning. Mohta et al. carried out a randomised trial of 100 mg phenylephrine boluses versus 5 mcg noradrenaline boluses to treat maternal postspinal hypotension during elective caesarean section. They hypothesised that noradrenaline would be less likely to cause bradycardia, due its weak b-agonist chronotropic action. Results showed no difference in the primary outcome of bradycardia, but the total number of phenylephrine boluses required was, perhaps unsurprisingly, greater than noradrenaline. Interestingly, the umbilical artery pH, bicarbonate and base excess were lower in the noradrenaline group which could have been as a result of placental transfer, but the mechanisms and clinical implications of this requires further investigation. 

Reducing the environmental impact of anaesthesia is a key strategic issue for the Association of AnaesthetistsKennedy et al., in a quality improvement study, provide novel data on how a single episode of high fresh gas flow at the start of anaesthesia can have a significantly modifiable effect on overall gas flow and vapour consumption. The authors provide us with useful conceptual framework (Figure 2) that suggests we need to be more mindful of our gas flows during induction. Hade et al. modified an existing central line insertion checklist by recommending insertion depths and adding a picture of a chest radiograph with a traffic light coloured tick-box system to assist with post-insertion tip confirmation (Figure 3). They report an impressive reduction in line tip malpositioning, along with improvements in documentation of other components of the checklist such as sterility measures. 

Figure 2. The three factors that are directly under the control of the anaesthetist that determine overall fresh gas flow (FGF) and vapour consumption: (1) the initial (high) FGF; (2) the duration of the initial FGF; (3) the FGF during the maintenance phase.

Figure 3. Central venous catheter checklist accompanied with the traffic light system.

Elsewhere, Luther et al., in a bench top study, observed that the brand of bougie, brand of double-lumen tube and size of double-lumen tube all influence the degree of bougie fragment shearing. This has implications for tube manufacturers who may consider specifying in advance which bougie could be safely used with their double-lumen tube. Dingley et al. investigated the effect of temperature control in different designs of emergency drug transport bags, which can have important consequences on the efficacy of emergency drugsGratz et al. successfully demonstrated the uptake of thromboelastometric-guided algorithms in emergency departments with no previous experience of such technology. Implementation of such algorithms has the potential to improve outcomes in patients with traumatic brain injury and suspected haemorrhage. 

In our reviews section, Roth et al. performed an excellent and highly clinically relevant abridged Cochrane review on the beside accuracy of bedside tests for predicting difficult airways. They found that, although none of the current tests are well suited for detecting anticipated difficult airways, the upper lip bite test had the most favourable test accuracy properties with a sensitivity of 67% and specificity of 92%. In the accompanying editorial, Law and Duggan discuss the challenges of current airway assessment strategies, offer advice on what to screen for and how to act if difficulty is predicted and suggest directions for future researchPoldermans et al. found no evidence that perioperative dexamethasone increases the risk of developing wound infections. It did produce a transient increase in glucose levels by a mean difference on 0.7 mmol.l-1, but data were on patients without diabetes mellitus. Surprisingly very little evidence currently exists on glycaemic control in patients with diabetes who receive dexamethasone, but the results of a large trial (8800 patients) with stratification of diabetes status are awaited. Some of the issues around dexamethasone administration and diabetes are discussed in an editorial by Albrecht and Wiles. They primarily focus on the some of the key findings of a recent NCEPOD report which reviewed the care of patients with diabetes who underwent surgical procedures. The authors make a strong case for departments to have clinical leads for the perioperative management with diabetes, alongside better utilisation the existing expertise of diabetic nurse specialists and better recognition of inadequate diabetic control in the operating theatre. 

Over on Anaesthesia Reports, we have two new cases – one on the use of high flow nasal oxygen in a high-risk obese patient requiring sedation in the prone position, and another on awake tracheal intubation for blunt airway trauma. We hope you enjoyed our most recent #FrontOfNeck TweetChat as much as we did. We were never really going to definitively settle the scalpel vs. cannula eFONA debate, but some of the associated discussions were fascinating! Finally, we look forward to seeing you at Association of Anaesthetists Trainee Conference in early July. Matt Wiles will be discussing evidence-based advances in trauma, Mike Charlesworth will be discussing contemporary mechanical circulatory support and Andy Klein will be presenting some of the best papers from Anaesthesia.

See you in Telford!

Professor Andy Klein and Dr Akshay Shah