Emergencies in anaesthesia

This month, we are delighted to publish our new special selection of review articles on emergencies in anaesthesia. Some of these reviews appear in the October issue and the others on Early View and in future issues. All are free to access for all, forever! 

First, Matt Wiles lists the evidence for airway management strategies in patients with suspected or confirmed traumatic spinal cord injury. He discusses: airway manoeuvres; manual in-line stabilisation; cricoid force; direct and indirect laryngoscopy; flexible bronchoscopy; and the associated risks of tracheal intubation. Overall, the risk of spinal cord injury during tracheal intubation appears to be minimal even in the presence of gross cervical spine instability. The evidence supporting practice choices is difficult to generalise to clinical practice, and practitioners should choose the tracheal intubation technique with which they are most proficient in the circumstances. 

Spoelder et al. discuss the transport of the patient with trauma, which is a complex process influenced by many factors. Immediate and precise identification of injury severity, with correct prioritisation of medical treatment and identification of the best mode of transport from accident scene to definite care, may impact morbidity and mortality. Edelman et al. bring together the last 5 years of studies reporting the prevalence and commonality of non-technical skills and human factors in airway management guidelines. They found that human factors were generally well represented in airway management guidelines but that further considerations are necessary for future clinical guidelines. McCahill et al. describe high quality basic care for the acutely unwell child, as well as advancements in the field which address issues around low case exposure and maintaining skills in different settings. Anaesthetists play a key role in the team of clinicians caring for sick children, which can be complex. Developments in training, cognitive aids, knowledge sharing and addressing human factors are vital to keep a workforce ‘paediatric ready’ to deal with these important emergencies. 

Prior et al. review six areas of obstetric emergencies: category-1 caesarean section; difficult and failed airway; massive obstetric haemorrhage; hypertensive crisis; emergencies related to neuraxial anaesthesia; and maternal cardiac arrest. They point to a need for more multidisciplinary training and simulation and outline the central role of obstetric anaesthetists in enhancing a culture of peri-delivery safety. Gottesman et al. review the concept of frailty, its epidemiology and approaches to evidence-based peri-operative management in the setting of emergency non-cardiac surgery. In the future there should be: specific focus on applying shared decision-making in time limited emergency surgery situations; optimal multidisciplinary peri-operative care pathways; effective frailty-friendly analgesic regimens; and effective physical and cognitive recovery after surgery. Finally, Shah et al. review the past, present and future of major haemorrhage.  They discuss: mechanisms; transfusion support; blood components;  ratios; pharmacological interventions; monitoring; and directions for future research (Fig. 1).

Figure 1 Key principles for the management of major haemorrhage in general, and across different clinical situations. MHP, major haemorrhage protocol; Hb, haemoglobin; RBC, red blood cell; PT, prothrombin time; FFP, fresh frozen plasma; PCC, prothrombin complex concentrate; TBI, traumatic brain injury; TXA, tranexamic acid. 

In the October issue, Sajayan et al. present their analysis of a national difficult airway database (Fig. 2). They find that unanticipated difficult airway management continues to occur despite airway assessment, and the rate of critical incidents in this cohort of patients is high. As has been reported before, there is still insufficient utilisation of safe techniques such as awake tracheal intubation when a difficult airway is anticipated. In the associated editorial, Smith and Rosenstock ask whether difficult airway cards help if practice doesn’t change?Anticipating airway management difficulties is an imperfect science, but we must better match the available techniques with patients identified or predicted to be at risk. 

Figure 2 Anticipated (blue) and observed (red) difficulties in airway management in patients included in this analysis (n = 675). Anticipated and observed values are not mutually exclusive as more than one difficulty can occur. FMV, facemask ventilation; SGA, supraglottic airway.

This new prospective study from Kohse et al. has been extremely well received already on social media, with over 500 likes for one tweet! They developed a multivariable model and score that associates intubation-related characteristics with subsequent issuing of a difficult airway alert after videolaryngoscopy, tailored to be used as a classification tool to grade difficult videolaryngoscopic intubation (Fig. 3). It demonstrates high discrimination and even outperformed the Cormack–Lehane classification. Will you be using it? 

Figure 3 The VIDIAC score is comprised of: E, the interaction between the blade tip and epiglottis; V, the best view of the vocal cords from the blade camera; and A, enlargement of the arytenoids. Illustration by Rasmus Borkamp, Hamburg, Germany.

In addition, we have: a systematic review of the analgesic benefits of the quadratus lumborum block in total hip arthroplastya review of mechanical ventilation in patients receiving extracorporeal membrane oxygenationa study of nocebo language in anaesthetic patient written informationa randomised controlled trial of interscalene block with 10 ml or 20 ml levobupivacaine 0.25% in patients undergoing arthroscopic shoulder surgery; and a study of the measurement of aerosols using a real-time sensor network

Dr Dmitri Nepogodiev presenting the Paper of the Year at Annual Congress 2022 in Belfast on behalf of the COVIDSurg collaborative.

Shelton and Kearsley provide their top tips on how to write and publish a case report in anaesthesia and peri-operative medicine. This article is a must for anyone wishing to write about their interesting cases and achieve publication in a high-quality journal such as Anaesthesia Reports! We hope you enjoyed the recent Annual Congress 2022 meeting in Belfast as we did. Here are those top 10 article from 2021, which are all free to download forever. Congratulations to the COVIDSurg collaborative, who achieved three spots in the countdown, including paper of the year!

Mike Charlesworth and Andrew Klein

Measuring and managing neuromuscular blockade

It is not clear yet why facemask ventilation becomes easier following neuromuscular blockade. This new prospective observational study from Lee et al. evaluates changes in tidal volume after administration of neuromuscular blockade and assesses the correlation of this with changes in the vocal cord angle. They found that tidal volume and vocal cord angle during induction of anaesthesia increased after neuromuscular blockade in patients with normal airways. In addition, both insufficiency of ventilation before neuromuscular blockade and improvement after neuromuscular blockade were correlated with vocal cord angle (Fig. 1). They suggest a new role for considering ‘vocal cord status’ to optimise facemask ventilation using neuromuscular blocking drugs. In the associated editorial, Chau and El-Boghdadly discuss the age-old question of whether adequate facemask ventilation should be confirmed before administering a neuromuscular blocking drug. They argue that drug administration is not just about a point of no return but about making the onward journey easier.

Figure 1 Increase in mean tidal volume before (black bars) and after (white bars) neuromuscular blockade. The bars indicate the mean and SD values. *p < 0.001 vs. before neuromuscular blockade.

In ICU patients, there is a risk of unintended residual neuromuscular blockade and associated complications. This new prospective study from Ross et al. aims to determine the incidence and identify associated factors. They found that it occurred in at least one-third of patients with no difference between postoperative and non-postoperative patients. Worryingly, 63% of New Zealand ICUs rarely test neuromuscular function before tracheal extubation, and 37% never do. In the associated editorial, Bailey simply states that if we cannot measure it, we cannot manage it. Afterall, as far as the administration of neuromuscular blockade is concerned, the ICU environment should be considered the same as the operating theatre.

Figure 2 Model inputs and output, with observed occurrence of residual neuromuscular blockade (RNMB): sex and postoperative status; predicted probability of RNMB; and whether RNMB was observed. Male (black); female (grey); non-postoperative (triangle); postoperative (circle); RNMB not observed (empty); RNMB observed (filled). (a) Rocuronium; (b) atracurium; (c) vecuronium; (d) pancuronium.

In the early COVID-19 pandemic, clinical guidelines in all areas of practices were changed beyond recognition in a matter of weeks and months. This new mixed methods study of UK anaesthetists from Shrimpton et al. looks at current practice and perceptions of so called ‘aerosol generating procedures’. The paper is rich with data and insight as well as lessons for the future. For example, some anaesthetists preferred using high level personal protective equipment during pre-operative patient assessment, despite this being at odds with national guidance. Overall, there was a call for more involvement of professional representative bodies, should practice change rapidly in this manner again. Severe maternal morbidity is of interest given that it is expected that historical reductions in maternal mortality might be reversed by increasing risk factors in the general population, such as obesity. This new cohort study from Masterson et al. found that severe maternal morbidity was recorded for about 1% of pregnant women in Scotland. Morbidity was independently associated with: maternal age; BMI; pre-existing morbidity; previous smoking; previous caesarean section; multiple pregnancy; and maternal birth in Africa or the Middle East. Morbidity was associated with delayed hospital discharge, stillbirths and maternal deaths. This paper was featured in the mainstream media with focussed placed on obesity as a significant risk factor. 

There is a need to prioritise equity, diversity and inclusion (EDI) within anaesthesia and medicine as a whole. This position statement outlines the Anaesthesia Editors’ current policies and practices aiming to achieve equity, represent the diversity of our specialty and actively include people engaged with this journal and beyond. We hope this will be an effective starting point towards embedding EDI into everything that the journal does and influences in clinical practice and academia. You can listen to a discussion of the statement, chaired by Association of Anaesthetists CEO Nicky de Beer, here. We all know that desflurane and nitrous oxide are bad for the environment, but how well can their avoidance and other strategies be implemented into clinical practice? This new guidance document from Devlin-Hegedus et al. provides recommendations for all clinicians that can be implemented right now. Will you start doing something different today? 

Another paper featured in major news outlets recently was this narrative review by Pandit et al. on the effect of overlapping surgical scheduling on operating theatre productivity. This might be a strategy that promises much in terms of reducing the waiting list backlog, but this must be balanced against the risk of adverse patient outcomes, safety, training and patient autonomy. You can read the associated press coverage here. Elsewhere we have: a feasibility trial of angiotensin-2 in cardiac surgerya pooled cross-sectional analysis of trends in country and gender representation on editorial boards in anaesthesia journalsa discussion of SARS-CoV-2 and airway reactivity in children; and a narrative review of the consequences of COVID-19 for chronic pain patients and services.

Finally, this month’s ‘Reviewer Recommendations’ tackles scientific dissemination, with the aim to get research to the people that need it. The authors argue that scientific dissemination is not an optional extra, and there is much work to be done to optimise dissemination tools in academic anaesthesia and peri-operative medicine. 

We have two big papers coming soon from important collaborative groups – PUMA and NAP! Look out for details of publication dates and live broadcasts, with PUMA set to launch their avoidance of oesophageal intubation guideline on Wednesday evening! We will see you for the broadcast on Thursday at 2000 BST. 

Mike Charlesworth and Andrew Klein

Effectiveness of emergency general surgery

We are all familiar with the successes of the National Emergency Laparotomy Audit, but what about those patients where emergency surgery is not appropriate? For five common acute surgical conditions, this new database study from Hutchings et al. compares those who did and did not receive emergency general surgery. They included nearly a million patients who were inpatients between 2010 and 2019. The primary outcome (DAH90) was similar for emergency surgery and non-emergency surgery strategies. However, the most striking result was the influence of frailty, age and number of comorbidities. There is a wealth of information which can be used to assist with discussions between clinicians and patients in the context of emergency general surgery. In the associated editorial, Forrester and Wren put the decision to operate in the context of its epidemiological triad (Fig. 1). They argue for caution when interpreting the results of Hutchings et al. because determining the ‘effectiveness’ of surgery is complex. It seems that more research is required and despite the advantages of instrument variable analysis provides, a prospective randomised study may provider more clarity.

Figure 1 Epidemiological ‘triads’.

Persistent pain following knee arthroplasty is common, and persistent opioid use in these patients is of concern. This new secondary analysis from Kluger et al. identified pre-operative opioid use, increased body mass index and multiple comorbid pain sites as important risk factorsIn the associated editorial, Levy et al. argue for the need to improve opioid prescribing in patients undergoing orthopaedic surgery. They look to the pre-operative period and highlight the fact that opioids are not a benign class of drug. Adverse effects include: increased surgical site infection risk; increased rate of early revision surgery; prolonged hospital stay; and greater likelihood of non-home discharge. 

There has been increasing evidence that lower doses of oxytocin and carbetocin following caesarean section are just as effective as higher doses but with a better side effect profile. This new double-blind, randomised, controlled, non-inferiority trial from McDonagh et al. compared the effect of low- and high-dose carbetocin and low- and high-dose oxytocin on uterine tone intensity at elective caesarean delivery. They found that low-dose carbetocin (20 μg) was non-inferior to high-dose carbetocin (100 μg) for the primary and secondary outcomes of uterine tone intensity at 2, 5 and 10 min after drug administration. Similarly, low-dose oxytocin (0.5 IU) was non-inferior to high-dose oxytocin (5 IU) for these outcomes (Fig. 2). A systematic review and network meta-analysis from Halliday et al. compared ultra-low, low and high concentration local anaesthetic for labour epidural analgesia. They found that ultra-low concentration local anaesthetic is associated with reduced total local anaesthetic dose, shorter first stage of labour and reduced incidence of Apgar < 7 at 1 min compared with low concentration, without compromising maternal analgesia, side-effect profile, satisfaction or neonatal outcomes. A narrative review from McCombe and Bogod brings together learning from 21 years of litigation for anaesthetic negligence resulting in peripartum hypoxic ischaemic encephalopathy. They explore four themes: delay; communication; hypotension following neuraxial anaesthesia; and documentation. Their paper is essential reading for all anaesthetists who work with pregnant women. Earlier this year, Plaat et al. published guidance on prevention and management of intra-operative pain during caesarean section under neuraxial anaesthesiaThis new editorial from McGlennan and Christmas explores the background to the paper as well as the clinical context. They remind us that we should always remain open to the possibility of a suboptimal block, and that true failure on behalf of the anaesthetist is failure to recognise and act. 

Figure 2 Box plot of uterine tone intensity assessed using verbal numerical rating scale (0–10) at 2, 5 and 10 min in each study group. Values are median (horizontal bars), IQR (box) and range (whiskers). Low-dose carbetocin (white solid); high-dose carbetocin (white shaded); low-dose oxytocin (grey solid); high-dose oxytocin (grey shaded). 

Elsewhere we have an evaluation of the outcome metric ‘days alive and at home’ in older patients after hip fracture surgery and an editorial praising developments in adult critical care transfer in England, which it is argued is a positive legacy of the COVID-19 pandemic. Finally, Miles and Story provide us with the first a new series of articles of ‘Reviewer Recommendations’. They takes us through the steps of how to design and publish quality science studies, which examine how readily and effectively research findings and guideline recommendations are translated into clinical practice and the outcomes of iterative quality improvement. These articles will become essential reading for anyone who wishes to increase their chances of publication acceptance not just in Anaesthesia, but wherever authors might choose to send their work. 

Make sure you book your place on the upcoming Annual Congress 2022 meeting in Belfast! We hope to see you there for plenty of great content including our annual paper of the year award. 

Mike Charlesworth and Andrew Klein

Implementing a checklist culture in peri-operative medicine

Despite several published guidelines recommending the use of peri-operative checklists, there is a paucity in reporting team adherence to checklist use. This new 5-year audit from Fuchs et al. aimed to report the adherence of anaesthesia providers to an anaesthesia pre-induction checklist. The checklist was to be undertaken before induction of anaesthesia and it included components related to: equipment; the patient; communication; and feasibility. They included 95,946 anaesthesia procedures with airway management, with overall completion in almost 60% of all procedures. They showed a 4.5% increase in the annual adherence rate (Fig. 1). Factors influencing adherence included the type of anaesthesia, variability between anaesthesia teams for different surgical specialities and urgent and daytime procedures. The checklist was used more frequently in the operating theatre, for non-emergency procedures and during daytime working hours. Saxena et al. draw comparisons with the well-known plane landing on the Hudson. Although well-designed checklists aim to reduce human error, they are only effective if implemented effectively. Regular audits like those reported by Fuchs et al. are useful to study patterns and reasons for non-compliance.

Figure 1 Adherence probability for the entire anaesthesia clinic (All) and stratified by anaesthesia team (as indicated), over time estimated with a binomial logistic regression model. Mean (solid lines) and 95% confidence limits (shaded areas) are shown.

During the early pandemic, there was much anecdotal evidence of a high incidence of right ventricular failure in ICU patients with COVID-19 and a suggestion of an association with mortality. Chotalia et al. undertook a retrospective observational study of 508 patients with COVID-19 pneumonitis of whom 305 (60%) underwent echocardiography. They identified three classes of patients from echocardiographic and clinical variables (Fig. 2). These subphenotypes had distinct clinical and outcome characteristics. McCall et al. add to this with their COVID-RV prospective study of 121 patients, of whom 112 (91%) underwent imaging. They found that the prevalence of right ventricular dysfunction was 6% and this was associated with a mortality of 86%, in contrast to 45% in those without right ventricular dysfunction. The associated editorial discusses the issues around imaging the right ventricle and determining when there is a problem. The key take-home message though is that we need to get better at echocardiography in ICU, perform it more regularly and use it to demonstrate, treat and monitor right ventricular injury earlier than we do currently.

Figure 2 Alluvial plot demonstrating the relationship between, on the left, clinically derived subphenotypes and on the right, latent class analysis-derived subphenotypes.

These new guidelines from the British Heart Rhythm were extremely well received on social media. Recommendations are provided around peri-operative pacemaker checking, functioning, deactivation and follow up. Before their initial release in 2016, there were no specific UK guidelines on this topic. Whilst much of the new update is based on expert opinion due mainly to a lack of trial date, anaesthetists are seeing more patients with cardiac implantable devices and the recommendations provided are of relevance to all. Two editorials feature in this issue that are associated with papers published earlier in the year. First, Ruslan and Smith make an argument for shorter and safer pre-operative fasting times in children. Afterall, the incidence of aspiration during anaesthesia for children in the associated study was approximately 0.1% and more than half of those that aspirated had an uneventful outcome. Second, Bailey and George ask, is further peri-operative research necessary for patients undergoing colorectal cancer surgery? They suggest that future trials should focus on homogenous surgery, a specific TIVA technique, a fixed intrathecal dose of opioid and patient outcome measures that matter.

Elsewhere we have a retrospective cohort study of ultrasound-guided caudal blockade and sedation for paediatric surgery and a randomised controlled feasibility trial of a clinical protocol to manage hypotension during major non-cardiac surgery. Finally, this meta-analysis from Pivetta et al. finds that the presence of obstructive sleep apnoea is associated with an almost two-fold increased risk of postoperative complications. There was also moderate certainty for patients with obstructive sleep apnoea having increased risk of cardiovascular complications (OR 1.56), atrial fibrillation (OR 1.74), respiratory complications, neurological complications, hospital and ICU re-admission postoperatively (Fig. 3).

Figure 3 Meta-analysis forest plots displaying odds ratio for postoperative complications in (a) non-cardiac surgeries and (b) cardiac surgeries. The odds ratio of each included study is plotted. A pooled estimate of overall odds ratio (diamonds) and 95%CIs (width of diamonds) summarises the effect size using the random-effects model. OSA, obstructive sleep apnoea; M-H, Mantel–Haenszel.

We have two livestreams coming very soon! The first is a live face-to-face discussion between our Associate Editor, Dr Tanya Selak and her colleague Dr Jessica Devlin-Hegedus. Dr Devlin-Hegedus was an author of a new paper which calls us all to action to reduce the environmental harms associated with volatile anaesthetics. This will be live on Twitter at 1000 BST on the 1st of July. The following week, we will be discussing our new position statement from the Editors on equity, diversity and inclusion. Date and time to be confirmed!

Mike Charlesworth and Andrew Klein

Major peri-operative complications

Major airway complications are rare and the best evidence on which we base current practice comes from NAP4, which was published in 2011. This new contribution from Cumberworth et al. used similar methods within six hospitals to see what has changed and highlight key areas for further training and development. They found an overall incidence of 1 in 3600 general anaesthetics, which is over six time that cited in NAP4. Even when certain cases were excluded that would have similarly been excluded in NAP4, the incidence remained higher. A key finding is that in those with a predicted easy airway, a standard approach of ‘anaesthesia induction followed by SAD/tracheal intubation’ very rarely results in serious airway complications. However, in those with a predicted difficult airway, this standard approach results in serious airway complication 45 times more frequently (Fig. 1). In the accompanying editorial, Armstrong and Cook list reasons as to why this new contribution is difficult to compare with NAP4. Importantly, it does not tell us the extent to which NAP4 recommendations were implemented. There still seems to be much to be done. Elsewhere, a more specialist paper from Peterson et al. reports complications associated with paediatric airway management during the COVID-19 pandemic. Their results, including that children with COVID-19 were 2.7 times more likely to experience hypoxaemia during tracheal intubation and extubation, challenge the belief that the implications of COVID-19 in children are insignificant. Clinicians should consider this when general anaesthesia is required.

Figure 1 Sequential management of the 17 cases of airway complication. ATI, awake tracheal intubation; DL, direct laryngoscopy; FONA, front of neck access; ICU, intensive care unit; PACU, post-anaesthesia care unit (recovery); SAD, supraglottic airway device; TT, tracheal tube. 

There has long been concern about patients undergoing major surgery with pre- or undiagnosed diabetes. This large prospective cohort study reveals a causal relationship between prevalent diabetes and adverse postoperative outcomes, which supports previous work. Going one step further though, the strength of the relationship between HbA1C and postoperative risk was lessened following adjustment for comorbid disease (Fig. 2). This begs the question, should we be targeting comorbidities, rather than short term glycaemic control? In the accompanying editorial, Polderman and Sieglaar argue the time has now come to find a place for pre-operative HbA1C screening, but how to optimise glycaemic control before surgery to improve outcomes remains a question with no answers.

Figure 2 Directed acyclic graph representing the casual relationship between HbA1c and postoperative complications. HbA1c, glycated haemoglobin; MI, myocardial infarction; CCF, congestive cardiac disease; PVD, peripheral vascular disease; and Composite, 30-day major postoperative complication and 90-day all-cause mortality. The green line from HbA1c to the composite outcome represents the direct casual pathway of HbA1c (direct effect). The blue risk factors represent mediators through which HbA1c also acts. If, after adjustment of mediators, an association is found between HbA1c and the composite outcome, this would suggest that HbA1c is not dependent on the mediators, that is, has a direct effect on the composite outcome. A direct effect would support optimisation of HbA1c before surgery. No direct effect would support optimisation of the mediators before surgery. 

There has been increasing concern about an increase in stress and mental illness including alcohol and substance use disorder in the medical workplace. There has also been more recent evidence suggesting a risk of suicide/accidental overdose among anaesthetists. This new Association of Anaesthetists guideline provides several recommendations in an area where there are insufficient resources available for anaesthetists, colleagues and medical managers. The good news is that over 75% of anaesthetists return to full practice if they co-operate fully with the required treatment and supervision. This new randomised controlled trial from Friedman et al. attracted a lot of attention recently on social media. They deliberate deceived trainee simulation participants by being told that the consultant was a subject in the study. Learners then participated in a simulated crisis that presented them with situational opportunities to challenge the consultant regarding clearly wrong decisions. They found that anaesthesia trainees were more effective at challenging a consultant’s clearly wrong clinical decision when they thought he was acting and a part of the simulation scenario. 

Has the shift to digital prehabilitation been forced by the COVID-19 pandemic? Durrand et al. remind us that patients are facing extended waits for surgery and we need to help patients wait better. Although digital solutions have advantages, one size can never fit all (Fig. 3). A co-ordinated national response comprising innovative solutions is required urgently to address this problem.

Figure 3 Framework for digitally facilitated prehabilitation support. PROM, patient-reported outcome measure; PREM, patient-reported experience measure.

Elsewhere we have: a narrative review of point-of-care assays in the management of postpartum haemorrhagea review of peri-operative care of elective adult surgical patients with a learning disability; and a study of ultrasound assessment of gastric contents in children before general anaesthesia for acute appendicitis

Finally, make sure you join us for this week’s livestream which is all about a paper looking at the effectiveness of emergency surgery for five common acute conditions. Friday 20th May 1000 BST, on Twitter!

Mike Charlesworth and Andrew Klein

Recruitment to higher specialty training in anaesthesia – we must do better

Any department will be familiar with the difficulties faced when appointing consultants or other senior doctors. We simply need more trained anaesthetists. Yet, the current trainee cohort have experienced major issues around all aspects of training, and this new survey elicits the associated consequences. It is, I believe, a landmark paper for several reasons. First, surveys are notoriously difficult to get right, especially as a full paper for publication in Anaesthesia. It serves as an excellent reminder of their utility, as well as how to do it. Second, this is a survey of trainees, by trainees, for trainees. The authors have responded to their own difficulties by producing a fine piece of academic work that will undoubtedly change things for others. Third, anyone involved with trainees and training should study the contents of the paper carefully, as we all have a duty to do better. Carey et al. discuss the recent curriculum and COVID-19 on training. It seems clear that more collaboration is needed between Royal Colleges, regulators and those who plan and run national recruitment processes. Clyburn et al. ask whether we have now created another lost tribe and make several recommendations as to how this cohort may one day be ‘found’.

Figure 1 Responses to questions about future plans (n = 437).

Are we all clear on how SARS-CoV-2 infection influences the timing of elective surgery, given that we now have vaccines and new variants? No? Look no further than this timely update from the Association of Anaesthetists, Centre for Perioperative Care, Federation of Surgical Specialty Associations, Royal College of Anaesthetists and Royal College of Surgeons of England. The main news is that previous recommendations that, where possible, patients should avoid elective surgery within 7 weeks of SARS-CoV-2 infection remain, unless the benefits of doing so exceed the risk of waiting. This is the key point though, as it is less about absolute rules and more about bespoke risk assessment and shared decision making. The paper contains a useful risk assessment template as well as a nicely written reminder about the importance of understanding relative vs. absolute risk.

Although we work in a low-risk specialty for litigation against doctors, it is important that we learn from claims to better understand clinical risk regarding trends, procedures and specialist areas of practice. This new analysis of claims made during 2008-2018 updates our understanding, which was based previously on work that is now a decade old. There are around 200 claims related to anaesthesia costing £14.5 million each year. Although this sounds like a lot, it is the equivalent of £4.39 per case. One of the surprises here is our reliance on researchers to do this work, as there are no formal processes to bring these data together. There must be a better way and the authors provide some excellent suggestions. Crosby argues that It’s time to eliminate tort from the management of medical mishaps in the NHS. Perhaps modifying the operation of NHS Resolution may allow it to do so meaningfully and eliminate the need for a new agency? D’Sa and Griffiths ask whether we can learn from our mistakes by looking in depth at medicolegal claims? They remind us that medicolegal risk is not the same as clinical risk, and we should reflect on which type of risk should drive changes in our practice. 

Figure 2 Proportion of claims by category in each of two time periods, 1995–2007 (blue) and 2008–2018 (grey).

Litigation arising from pain during caesarean section under neuraxial anaesthesia has replaced accidental awareness under general anaesthesia as the most common successful medicolegal claim against obstetric anaesthetists. These new recommendations are the only ones available in this area and benefit from the experience of a patient, who is also an author. The importance of effective communication is a strong theme running throughout as is the need to support clinicians and promote standardisation of practice in this area. The guidelines are accompanied by a systematic review from Patel et al. which find that approximately 1 in 1750 women require conversion to general anaesthesia due to inadequate neuraxial anaesthesia, and 15% require supplemental analgesia or anaesthesia ranging from nitrous oxide to general anaesthesia. In the associated editorial, Stanford (the patient author of on the authorship group) reminds us that the ends (a well baby) do not always justify the means, and inadequate neuraxial anaesthesia is associated with long-term psychological consequences. Afterall, physical safety is the bare minimum of what should be expected during caesarean sections.  

Elsewhere we have: an e-Delphi process with training facilitators of Priorities for content for a short-course on postoperative care relevant for low- and middle-income countriesa retrospective study of the effect of iron deficiency without anaemia on days alive and out of hospital in patients undergoing valvular heart surgery; anda prospective study of functional recovery after discharge in enhanced recovery video-assisted thoracoscopic lobectomy.

Finally, this prospective randomised trial from Hestin et al. aimed to elucidate whether general or regional anaesthesia is better for surgical evacuation of chonic subdural haematoma. In terms of time to become medically fit for discharge or postoperative complications, there was no difference and both techniques were comparable. In the associated editorial, Dinsmore and Wiles argue that patients should receive the anaesthetic that is best for them, and no large RCT will ever prove one technique to be superior than the other. Perhaps we now need to treat surgery for chronic subdural haematoma like that for hip fracture. This would require standardised care packages for the whole patient journey, rather than just the peri-operative period.  

Booking is now open for Annual Congress in September later this year, which be a face-to-face meeting! We hope to see you there! Our journal session will focus on emergencies relevant to those working in anaesthesia, critical care and pain.

Mike Charlesworth and Andrew Klein

Advanced care plans in the peri-operative period

For many, the COVID-19 pandemic brought the stark reality of our mortality into focus. Along with the controversial application of ‘blanket’ DNACPR orders, it has forced all in the profession to consider how we involve our patients in the difficult conversations and decisions regarding end-of-life care. The development of the ReSPECT process by the Resuscitation Council (UK) encourages patients in the community and hospital to create personalised recommendations for clinical care if they are unable to make or express their choices in a future emergency. In view of the changing landscape of advance care planning, the Association of Anaesthetists has created guidelines on implementing advance care plans in the peri-operative period. This is a consensus document produced by expert members of a working party and endorsed by the Resuscitation Council (UK) and Compassion in Dying. It highlights that advance care plans are to allow for patient-centred outcomes, and clarifies how to discuss, and deal with, DNACPR decisions in the peri-operative period. 

Continuing with the theme of patient-centred outcomes, this important systematic review and meta-analysis by McPeake et al. looked at hospital readmission after critical care and found that over 50% of previous critical care patients were readmitted to hospital within one year. Risk factors included co-morbidities, delirium, mechanical ventilation during the initial admission and infection after discharge. In the associated editorial, Plummer and Lonecomment on how these risk factors might be modified, and if so, what interventions are appropriate and possible. We all too often do not think past mortality for our outcomes; this study highlights how critical illness impacts patients, their families and healthcare resources, and states the case for targeted interventions for at-risk critical care survivors to reduce morbidity post-discharge. 

Clearly you should never judge an article purely by its title but ‘Regional analgesia following caesarean section: new kid and a block?’ is as incisive as an editorial as its title is witty (especially if you are a child of the 80-90’s). Kearsley et al. provide comment on a network meta-analysis performed by Singh et al. looking at the efficacy of regional blocks or local anaesthetic infiltration for caesarean section analgesia. Using a random effects Bayesian model they performed a network meta-analysis including 8730 parturients and found that bilateral ilio-inguinal blocks provided the highest reduction in 24-hour morphine equivalents, regardless of whether intrathecal morphine was administered. The associated editorial suggests that perhaps the time for transversus abdominus plane blocks is over and that ilio-inguinal blocks could be added to the RA-UKs Plan A blocks; but also appreciate the resource implication this may have as ilio-inguinal blocks require ultrasound provision. Step by step regional analgesia for caesarean section is becoming clearer.

One article that has garnered a lot of social media debate is a randomised controlled trial of a novel tramadol chewable tablet: pharmacokinetics and tolerability in children. Yoo et al. formulated a chocolate-flavoured tramadol tablet and performed a pilot RCT in a single centre. The chocolate tramadol tablet was found to have a higher bioavailability, quicker absorption and be better tolerated than liquid tramadol (Fig. 1). 

Figure 1 Taste tolerability scores obtained from children, parents and nurses for (A) the tramadol chocolate-based drug delivery system tablet and (B) tramadol liquid formulation. The 5-point facial hedonic scale was: 1 = dislike very much; 2 = dislike a little; 3 = not sure; 4 = like a little; and 5 = like very much.

If tramadol isn’t your paediatric analgesic of choice, Saffer et al. present a randomised controlled trial comparing oral paracetamol with water versus just water 1 h pre-operatively. They found that, in 97 children aged between 1 and 96 months, there was no significant difference in either gastric aspirate volume or pH between the groups. The authors acknowledge that some centres may already give pre-operative oral paracetamol, but this study provides reassurance that with reducing fasting times, pre-operative oral paracetamol is a safe alternative to the more expensive intra-operative intravenous option. 

Following on from last month’s consensus statement on academic publishing of papers from low-to-middle-income countries, Stahlschmidt et al., present a convincing before and after cohort study on enhanced peri-operative care to improve outcomes for high-risk surgical patients in Brazil. They created a 48-hour post-operative care bundle (Fig. 2) and demonstrated that increased surveillance of these high-risk patients reduced 30-day mortality. Enhanced post-operative surveillance of high-risk patients is potentially viable for use in other LMIC settings where critical care resource is scarce.

Figure 2 High-risk bundle compliance evaluation.

This month also sees the publication of an randomised controlled trial of a text message intervention to reduce burnout amongst trainee anaesthetists. No significant difference was demonstrated between trainees who received fortnightly text messages based on behavioural techniques to reduce burnout and those who did not. However, exploratory post-hoc analysis did demonstrate that burnout symptoms were reduced in trainees identified as having personal or work-related difficulties, and those particularly affected by the pandemic. Importantly, the authors found that there was no backfire effect which makes this a safe intervention. It is unfortunate that studies such as this are having to be performed, and the associated podcast discusses some of the factors surrounding trainee burnout.

Elsewhere, we have a retrospective cohort study on obstetric anaesthesia and analgesic practices for in SARS-CoV-2 positive patients; a service evaluation on the effect of transfer from critical care areas for mechanically ventilated SARS-CoV-2 patients; an editorial with practical tips on how we, as anaesthetists, can contribute towards combatting the global heating emergency and an editorial on the future of space anaesthesia!

Finally, attention now shifts to meeting again face-to-face later this year in Belfast. Booking for Annual Congress 2022 is now open! We are very much looking forward to seeing you there.

Cara Hughes and Andrew Klein

Advancing global health research equity

Parachute (or ‘helicopter’) research is the practice of conducting primary research within a host country and subsequently publishing findings with inadequate recognition of local researchers, staff and/or supporting infrastructure. In fact, almost 30% of publications of primary research conducted in LMICs did not contain any local authors. This new consensus statement from Morton et al. contains six recommendations which apply not just to research in our field, but broadly within academic publishing. It has achieved an Altmetric score of nearly 400, which demonstrates how well it was received by the academic community. A key element is the structured reflexivity statement, which the authors suggest should be completed with manuscript submissions from international research partnerships involving researchers from high- and low-to-middle-income countries. In the accompanying editorial, Jumbam et al. build upon this by encouraging journals and journal editors to adopt the recommendations (Fig. 1), and by encouraging us all to consider the reflexivity statement at every timepoint during project conception and implementation.

Figure 1 The position and power of journals within the global health research ecosystem. Journals influence the ecosystem by: (a) brokering research outputs which are predominantly led from HIC institutions; and (b) direct editorial statements (e.g. through ‘commissions’). These journal activities influence research prioritisation and funding allocation. The current predominance of HIC outputs and perspectives in journal activities further amplifies the impact of HIC perspectives on donor funding and research agendas. This can worsen existing inequities. 

In the UK, the Getting It Right First Time (GIRFT) programme was established by the Department of Health and Social Care as an initiative to investigate variation in healthcare delivery and patient outcomes between hospital Trusts in England. For their new paper, Gray et al. used the Hospital Episodes Statistics (HES) database to investigate variation in the rates Trusts discharged children the same day after tonsillectomy and associations with adverse postoperative outcomes. They provide evidence that outcomes for day-case and overnight stay tonsillectomy are similar, and argue the majority of specialist and non-specialist Trusts should increase day-case surgery rates. In the associated editorial, Stocker asks, why is there still a debate? Afterall, admitting a child to hospital is disruptive and, on occasions, distressing for not just the child but their extended family, as it necessitates the child and a parent to be away from the family home overnight. 

Video-assisted thoracoscopic surgery is associated with less pain and better recovery as compared with thoracotomy. Although enhanced recovery after surgery guidelines have been described, this PROSPECT guideline is the first specifically address evidence-based analgesia strategies. Recommendations support the use of: paravertebral and erector spinae plane blocks; systemic multimodal analgesia; intra-operative dexmedetomidine; and rescue opioids. The authors do not support thoracic epidural analgesia. In the associated editorial, Shelley et al. remind us that the supportive evidence for regional anaesthetic techniques in this cohort is weak. Although the guidelines are a useful benchmark, an individualised approach remains paramount, and more evidence is required urgently.

Obstructive sleep apnoea (OSA) is highly prevalent in the general population. This new secondary analysis from Moringo et al. aims to determine whether the STOP-Bang questionnaire can be distilled to develop an abbreviated screening tool to identify patients at high risk for severe OSA. They found that it can be reduced from eight to four variables to effectively identify patients at high risk for severe OSA. Neck circumference was most strongly associated with severe OSA, while observed apnoea, high blood pressure and BMI trended towards significance (Fig. 2). These four variables were termed the B-APNEIC score and together they demonstrated similar predictive accuracy to the STOP-Bang questionnaire for identifying individuals at high risk for severe OSA. In the associated editorial, Singh and Ramachandran welcome the B-APNEIC score and call for more research in areas such as POCUS screening, outcome prediction models and individualised evidence-based postoperative management strategies

Figure 2 Receiver operating characteristic curves of STOP-Bang questionnaire vs. B-APNEIC score for clinical diagnosis of severe obstructive sleep apnoea (OSA), severe apnoea-hypopnoea index (AHI), severe respiratory disturbance index (RDI) and severe oxygen desaturation index (ODI).

Many will routinely mix local anaesthetic agents or add adjuncts to alter block characteristics, but what are the true clinical consequences of this practice? Nestor et al. review the evidence, and find the supportive evidence to be lacking. They remind us that the long list of potential adjuncts will continue to grow if the vogue for mixing untested and unlicensed medications persists. Furthermore, doctors must be cognisant that, once the decision is made to use an ad-hoc admixture, they bear all responsibility and will be liable in the event of an adverse event. The same team also discuss mixtures of intravenous infusions in the context of target-controlled infusion systems. They argue that mixing two or more drugs in a syringe constitutes an unjustifiable patient risk, and has no place in modern practice. Do you agree? Send us a letter and we will publish it!

Elsewhere we have: a randomised controlled trial of erector spinae plane block vs. peri-articular injection for pain control after arthroscopic shoulder surgeryan assessment of introducers used for airway management; and a network meta-analysis of videolaryngoscopy vs. direct laryngoscopy for tracheal intubation in adults

Finally, make sure you catch up with two recent podcasts looking at perceptions of recruitment to higher specialty training during the COVID-19 pandemic and a randomised controlled trial of a text message intervention to reduce burnout in trainee anaesthetists. Both are essential listening and reading for all!

Mike Charlesworth and Andrew Klein

Intra-operative hypotension – how low should you go?

The February issue of Anaesthesia attempts to answer the age-old question plaguing anaesthetists – what blood pressure should we be targeting and how much does it matter? We are delighted to present the first publication from the iHype study – a prospective cohort study designed and conducted by the Research and Audit Federation of Trainees (RAFT). Data from 4750 patients aged >65 y were collected over a 48 h period. They found intra-operative hypotension, and its many different definitions, to be common, with incongruence between the blood pressure anaesthetists say they will treat and their actual treatment threshold. This study is a great example of what trainee research networks can achieve and how they are a relatively untapped resource. The podcast discussion with the authors is a must for any budding trainee researcher on how to plan and perform such a large and effective study. The associated editorial highlights the discrepancy between blood pressure recordings and explores why we feel may feel the need to “fudge” the anaesthetic chart. With electronic recording becoming more prevalent in the future there may be nowhere to hide! 

Figure 1 Thresholds at which anaesthetists give vasopressor treatments and their intended treatment thresholds. Y-axis denotes the proportion of patient episodes/respondents given the defining threshold on the x-axis for (a) absolute mean arterial pressure; (b) absolute systolic blood pressure; (c) relative change in mean arterial pressure from pre-operative blood pressure; and (d) relative change in systolic blood pressure from pre-operative blood pressure.

The effect of intra-operative hypotension on acute kidney injury, postoperative mortality and length of stay following emergency hip fracture surgery is a neat single centre study investigating the incidence of intra-operative hypotension in a vulnerable group. Interestingly, they did not find an association with intra-operative hypotension and acute kidney injury. However, delay to surgery was associated with increased mortality. North Shore Hospital Anaesthetic department do use electronic intra-operative recording and the MAP was (truly) rarely below 65mmHg in their cohort. 

Why does blood pressure drop during anaesthesia and is there anything we can do to predict which patients will be most affected? The editorial by Frandsen et al. goes back to basic physiology and highlights the often forgotten about autonomic system – it is not all about intra-vascular volume. Anaesthesia causes both sympatholysis and vagolysis. If a patient already has pre-existing autonomic dysfunction, despite adequate fluid volume, anaesthesia could and does provoke hypotension and cardiac instability. By using pre-operative markers of vagal tone, such as heart rate variability, can we identify high risk patients and tailor our anaesthesia accordingly?

The pandemic has sharpened and exacerbated health and social inequalities globally. There is no doubt that patients of non-white ethnicity have poorer outcomes from SARS-CoV-2 infection. The underlying cause for this is likely to be multi-factorial but there has been anxiety that pulse oximetry is less accurate in patients with darker skin pigmentations. Wiles et al. performed a retrospective observational study to address this important concern. They compared SaO2 and SpO2 measured concurrently in patients on different ethnicities and reassuringly found no clinically significant difference. However, as mentioned in the accompanying editorial – is ethnicity the correct question to be asking, and should we actually be comparing skin pigmentation levels in order to accurately validate the use of pulse oximetry in different groups? The inclusion of different ethnic groups in both clinical research and validation studies of commercial monitoring is improving, but this topic highlights the need for both patients and medical staff to be confident that what we are both doing and using to monitor patients in different diseases is correct for all patients. 

Figure 2 Bland-Altman plot paired measurements of oxygen saturation by arterial blood gas analysis and peripheral oxygen saturation in 194 patients with COVID-19 pneumonitis who were admitted to critical care for non-invasive respiratory support. Patient ethnic origin is shown by the colour of each datum (White = yellow; Asian = purple; Black = light blue; and Other = green). The solid line represents the bias between the two measurements, the dashed line represents the limits of agreement (bias ± 1.96 SD) and the dotted line represents the 95%CI for the limits of agreement. (a) shows all paired measurements and (b) shows only those measurements when the patient was hypoxaemic (defined as SaO2 ≤94%).

The pandemic has also made us aware of the vital importance of oxygen and how hypoxic patients do not always look the same! However, aside from being able to sketch out the oxygen dissociation curve, our actual understanding of oxygen physiology is limited. Slingo and Pandit present a narrative review aiming to introduce hypoxia-inducible factor and oxygen sensing pathways to the wider clinical community. The ability of cells to detect and respond to varying oxygen concentrations relies on a complex cascade. Manipulation of this pathway may have many clinical implications, including targeted oxygen therapy. This fascinating review also highlights the requirement for more basic science research in anaesthesia.

Figure 3 Several hundred genes are direct transcriptional targets of HIF, and are involved in diverse cellular and physiological processes in order to optimise oxygen supply and demand. A few examples are given here that will be of direct interest to clinicians in anaesthesia and critical care. VEGF, vascular endothelial growth factor; TF, transferrin; EPO, erythropoietin; Hb, haemoglobin; Hct, haematocrit; EDN1, endothelin 1; NOS, nitric oxide synthase; GLUT 1, glucose transporter 1; LDH, lactate dehydrogenase; PDK1, pyruvate dehydrogenase kinase 1.

The expanding field of peri-operative medicine is changing the focus of anaesthesia research. Along with clinical shared decision-making, patient involvement in study design is improving and with that the need for outcomes that are important for patients. Days alive and at home (DAH) is one such outcome that neatly encompasses the many factors of the post-operative journey for a patient. Ferguson et al. surveyed patients and found the minimal clinically important difference to be 3 days, with an early discharge and being discharged to home rated as important. This is important work that will guide study design in future trials. Indeed Moore et al. used a similar patient-centred outcome measure (days alive and out of hospital) to audit the implementation of the WHO Surgical Safety Checklist.

None of the above research into patient outcomes however is important if we do not have a world in which to practice anaesthesia! In light of COP26 in Glasgow in November the World Federation of Societies of Anaesthesiologists has produced a consensus statement on the principles of environmentally-sustainable anaesthesia. The main points are that patient safety should not be compromised and healthcare systems should be mandated to reduce their contributions to global heating in order to limit global heating to 1.5℃ by 2050. There is a lack of scientific evidence to underpin these guidelines and further work and investment is needed to ensure that we protect our world and current and future generations.

Elsewhere we also have a feasibility study on the use of cryoprecipitate in post-partum haemorrhage. Finally, we are recruiting! We have adverts for a Trainee FellowEditor-in-Chief and three Editors posts at Anaesthesia Reports! Join us!

Cara Hughes and Andrew Klein

Current evidence for peri-operative and critical care management of the brain

What better way to see in any new year than with a brand-new Anaesthesia Special Supplement! This year, it is all about the peri-operative and critical care management of the brain, which has been guest edited by Dr Jugdeep Dhesi and Professor Alana Flexman. Flexman and Tung begin by appraising outcomes used in neuroanaesthesia and neurocritical care. They call for a shift towards PROMS as well as perspectives from LMICs, and the tools are available now – we just have to use them. Dhesi and Moppett discuss the implications of the older brain in peri-operative care and ask – what should we do? As we most things, there is no one right answer and no ‘magic bullet’, but one of the key themes appearing throughout the issue is of multidisciplinary thinking and working. The first review seems to have caught the imagination of our followers already, which looks at the implications of nocebo. This is a key paper that could potentially change practice, but not everyone will agree, as many of the nocebos in use are enshrined in practice already (Fig. 1). Time now for phrases such as ‘bee sting’ and ‘sharp scratch’ to be thought of as clumsy verbal relics of the past? We think so!

Figure 1 Overview of the neurobiology of the nocebo effect. PONV, postoperative nausea and vomiting; ACTH, adrenocorticotrophic hormone; CCK, cholecystokinin; PFC, prefrontal cortex; ACC, anterior cingulate cortex; HPA, hypothalamic–pituitary–adrenal axis; PAG, peri-aqueductal gray.

Stubbs et al. use a stereotyped peri-operative journey to highlight the decision-making points where the expertise of professionals from across the peri-operative medicine team may play an important role for patients with chronic subdural haematoma. The key point is that most patients are managed outside neuroscience centres, and more research is needed to improve the associated care pathways. Peri-operative neurocognitive disorders are the most common complication experienced by older individuals undergoing anaesthesia and surgery. Evered et al. discuss the clinical and practical implications of peri-operative neurocognitive disorder on patients, and possible pathways for identifying at-risk individuals and assessment of modifiable factors.Possible mechanisms include: neurodegenerative disease; inflammation; neuronal damage; and frailty. No longer should we refer to patients as ‘pleasantly confused’ as arguably, there is nothing pleasant about delirium. 

There is much emerging evidence of COVID-19-associated delirium, and White and Jackson have brought it all together for us. They describe how it differs from ‘classical’ delirium, as well as potential mechanisms and practical approaches to management (Fig. 2). It turns out that it is more prevalent, longer lasting and associated with worse outcomes. The management remains the same, except for distressing end of life agitation where the need for higher-than-normal doses of sedatives may be required. One area of persistent controversy in neuroanaesthesia relates to the mode of anaesthesia and its relation with outcomes for mechanical thrombectomy. Dinsmore and Tan review the evidence, and suggest more important targets such as blood pressure management, diagnosis and timely management

Figure 2 Lived experience of delirium for patients, staff and families.

Is anyone using POCUS for acute brain injury? Dinsmore and Venkatraghavan describe the techniques and applications for and provide evidence of its utility in guiding clinical management both in the peri-operative period and on ICU. They list the commonly used acoustic windows and the structures that are visible. They argue it is an effective, non-invasive, safe and readily available technique for the rapid assessment of cerebral anatomy and cerebral haemodynamics. Will it become an alternative routine imaging technique? The results seem comparable. Most doctors will encounter status epilepticus in their carrer. Migdady et al. discuss the definitions of status epilepticus, evidence behind treatment regimens at various stages, treatment goals, outcomes and the role for newer drugs. Implementing early, evidence-based treatment modalities is important to prevent mortality and complications from prolonged status epilepticus, and this paper is arguably of important relevance for all!

Figure 3 Treatment timeline of convulsive status epilepticus. *intramuscular (IM) or buccal (depending on availability) preferred in patients without i.v. access. Diazepam can be used if lorazepam and midazolam are not available. ABC, airway, breathing and circulation; IV, intravenous; AED, anti-epileptic drug; CBC, complete blood count; CMP, complete metabolic panel; CT, computed tomography; EEG, electroencephalogram; MRI, magnetic resonance imaging; KD, ketogenic diet; rTMS, repetitive transcranial magnetic stimulation; and VNS, vagal nerve stimulator.

Have you been busy with COVID-19 over the last few years and missed the most recent CPD relevant to the management of traumatic brain injury? Fear not, Matt Wiles has reviewed the recent evidence and brought it all together. In summary, there are few clear therapeutic interventions that are associated with meaningful improvements in mortality, or more importantly, neurological outcome. The early administration of TXA appears to offer a clinically important early mortality benefit and early tracheostomy appears to be of value. Kayambankadzanja et al. review pragmatic sedation strategies to prevent secondary brain injury in low-resource settings, which is common. They emphasise the importance of analgesia, the choice of drugs, the associated risks and the monitoring required for these patients in these settings. Elsewhere we have reviews of: strategies to reduce the incidence of postoperative deliriumperi-operative neurological monitoring with electroencephalography and cerebral oximetry; and the peri-operative management of patients with Parkinson’s disease

Figure 4 Summary of recent evidence-based recommendations for the management of traumatic brain injury.

We hope you enjoyed the live broadcast to accompany the issue which was seen by over 2.5k viewers! This has now been converted into a podcast which available in all the usual places. Enjoy!

Mike Charlesworth and Andrew Klein