Peri-operative cardiac arrest due to suspected anaphylaxis as reported to the 7th National Audit Project of the Royal College of Anaesthetists.

The 7th National Audit Project (NAP7) of the Royal College of Anaesthetists studied peri-operative cardiac arrest. Among 59 cases reported as possible anaphylaxis, 33 (56%) were judged to be so by the review panel with high or moderate confidence. Causes in excluded cases included: isolated severe hypotension; bronchospasm; and oesophageal intubation. Severe bronchospasm leading to cardiac arrest was uncommon, but notably in one case led to a reported flat capnograph. In the baseline survey, anaesthetists estimated anaphylaxis as the cause of 10% of cases of peri-operative cardiac arrests and to be among the four most common causes. In a year-long registry of peri-operative cardiac arrest, suspected anaphylaxis was the seventh most common cause accounting for 4% of reports. Initial management was most often with low-dose intravenous adrenaline, and this was without complications. Both the NAP7 baseline survey and case registry provided evidence of reluctance to starting chest compressions when systolic blood pressure had fallen to below 50 mmHg and occasionally even when it was unrecordable. All 33 patients were resuscitated successfully but one patient later died. The one death occurred in a relatively young patient in whom chest compressions were delayed. Overall, peri-operative anaphylaxis leading to cardiac arrest occurred with a similar frequency and patterns of presentation, location, initial rhythm and suspected triggers in NAP7 as in the 6th National Audit Project (NAP6). Outcomes in NAP7 were generally better than for equivalent cases in NAP6.

Airway and respiratory complications during anaesthesia and associated with peri-operative cardiac arrest as reported to the 7th National Audit Project of the Royal College of Anaesthetists.

The 7th National Audit Project (NAP7) of the Royal College of Anaesthetists studied complications of the airway and respiratory system during anaesthesia care including peri-operative cardiac arrest. Among 24,721 surveyed cases, airway and respiratory complications occurred commonly (n = 421 and n = 264, respectively). The most common airway complications were: laryngospasm (157, 37%); airway failure (125, 30%); and aspiration (27, 6%). Emergency front of neck airway was rare (1 in 8370, 95%CI 1 in 2296-30,519). The most common respiratory complications were: severe ventilation difficulty (97, 37%); hyper/hypocapnia (63, 24%); and hypoxaemia (62, 23%). Among 881 reports to NAP7 and 358 deaths, airway and respiratory complications accounted for 113 (13%) peri-operative cardiac arrests and 32 (9%) deaths, with hypoxaemia as the most common primary cause. Airway and respiratory cases had higher and lower survival rates than other causes of cardiac arrest, respectively. Patients with obesity, young children (particularly infants) and out-of-hours care were overrepresented in reports. There were six cases of unrecognised oesophageal intubation with three resulting in cardiac arrest. Of these cases, failure to correctly interpret capnography was a recurrent theme. Cases of emergency front of neck airway (6, approximately 1 in 450,000) and pulmonary aspiration (11, approximately 1 in 25,000) leading to cardiac arrest were rare. Overall, these data, while distinct from the 4th National Audit Project, suggest that airway management is likely to have become safer in the last decade, despite the surgical population having become more challenging for anaesthetists.

Peri-operative cardiac arrest in the older frail patient as reported to the 7th National Audit Project of the Royal College of Anaesthetists.

Frailty increases peri-operative risk, but details of its burden, clinical features and the risk of, and outcomes following, peri-operative cardiac arrest are lacking. As a preplanned analysis of the 7th National Audit Project of the Royal College of Anaesthetists, we described the characteristics of older patients living with frailty undergoing anaesthesia and surgery, and those reported to the peri-operative cardiac arrest case registry. In the activity survey, 1676 (26%) of 6466 patients aged > 65 y were reported as frail (Clinical Frailty Scale score ≥ 5). Increasing age and frailty were both associated with increasing comorbidities and the proportion of surgery undertaken as an emergency. Except in patients who were terminally ill (Clinical Frailty Scale score 9), increasing frailty was associated with an increased proportion of complex or major surgery. The rate of use of invasive arterial blood pressure monitoring was associated with frailty only until Clinical Frailty Scale score 5, and then plateaued or fell. Of 881 cardiac arrests reported to the 7th National Audit Project, 156 (18%) were in patients aged > 65 y and living with frailty, with an estimated incidence of 1 in 1204 (95%CI 1 in 1027-1412) and a mortality rate of 1 in 2020 (95%CI 1 in 1642-2488), approximately 2.6-fold higher than in adults who were not frail. Hip fracture, emergency laparotomy, emergency vascular surgery and urological surgery were the most common surgical procedures in older patients living with frailty who had a cardiac arrest. We report a high burden of frailty within the surgical population, requiring complex, urgent surgery, and the extent of poorer outcomes of peri-operative cardiac arrest compared with patients of the same age not living with frailty.

Independent sector and peri-operative cardiac arrest as reported to the 7th National Audit Project of the Royal College of Anaesthetists.

The 7th National Audit Project (NAP7) of the Royal College of Anaesthetists studied peri-operative cardiac arrest including those that occurred in the independent healthcare sector, which provides around 1 in 6 NHS-funded care episodes. In total, 174 (39%) of 442 independent hospitals contacted agreed to participate. A survey examining provider preparedness for cardiac arrest had a response rate of 23 (13%), preventing useful analysis. An activity survey with 1912 responses (from a maximum of 45% of participating hospitals) showed that, compared with the NHS caseload, the independent sector caseload was less comorbid, with fewer patients at the extremes of age or who were severely obese, and with a large proportion of elective orthopaedic surgery undertaken during weekday working hours. The survey suggested suboptimal compliance rates with monitoring recommendations. Seventeen reports of independent sector peri-operative cardiac arrest comprised 2% of NAP7 reports and underreporting is likely. These patients were lower risk than NHS cases, reflecting the sector's case mix, but included cases of haemorrhage, anaphylaxis, cardiac arrhythmia and pulmonary embolus. Good and poor quality care were seen, the latter including delayed recognition and treatment of patient deterioration, and poor care delivery. Independent sector outcomes were similar to those in the NHS, though due to the case mix, improved outcomes might be anticipated. Assessment of quality of care was less often favourable for independent sector reports than NHS reports, though assessments were often uncertain, reflecting poor quality reports. Overall, NAP7 is unable to determine whether peri-operative care relating to cardiac arrest is more, equally or less safe than in the NHS.

Cardiac arrest in obstetric patients receiving anaesthetic care: results from the 7th National Audit Project of the Royal College of Anaesthetists.

The 7th National Audit Project (NAP7) of the Royal College of Anaesthetists studied peri-operative cardiac arrest. Additional inclusion criteria for obstetric anaesthesia were: cardiac arrest associated with neuraxial block performed by an anaesthetist outside the operating theatre (labour epidural analgesia); and cardiac arrest associated with remifentanil patient-controlled analgesia. There were 28 cases of cardiac arrest in obstetric patients, representing 3% of all cardiac arrests reported to NAP7, giving an incidence of 7.9 per 100,000 (95%CI 5.4-11.4 per 100,000). Obstetric patients were approximately four times less likely to have a cardiac arrest during anaesthesia care than patients having non-obstetric surgery. The single leading cause of peri-operative cardiac arrest in obstetric patients was haemorrhage, with underestimated severity and inadequate early resuscitation being contributory factors. When taken together, anaesthetic causes, high neuraxial block and bradyarrhythmia associated with spinal anaesthesia were the leading causes overall. Two patients had a cardiac arrest related to labour neuraxial analgesia. There were no cardiac arrests related to failed airway management or remifentanil patient-controlled analgesia.

Peri-operative decisions about cardiopulmonary resuscitation among adults as reported to the 7th National Audit Project of the Royal College of Anaesthetists.

Current guidance recommends that, in most circumstances, cardiopulmonary resuscitation should be attempted when cardiac arrest occurs during anaesthesia, and when a patient has a pre-existing 'do not attempt cardiopulmonary resuscitation' recommendation, this should be suspended. How this guidance is translated into everyday clinical practice in the UK is currently unknown. Here, as part of the 7th National Audit Project of the Royal College of Anaesthetists, we have: assessed the rates of pre-operative 'do not attempt cardiopulmonary resuscitation' recommendations via an activity survey of all cases undertaken by anaesthetists over four days in each participating site; and analysed our one-year case registry of peri-operative cardiac arrests to understand the rates of cardiac arrest in patients who had 'do not attempt cardiopulmonary resuscitation' decisions pre-operatively. In the activity survey, among 20,717 adults (aged > 18 y) undergoing surgery, 595 (3%) had a 'do not attempt cardiopulmonary resuscitation' recommendation pre-operatively, of which less than a third (175, 29%) were suspended. Of the 881 peri-operative cardiac arrest reports, 54 (6%) patients had a 'do not attempt cardiopulmonary resuscitation' recommendation made pre-operatively and of these 38 (70%) had a clinical frailty scale score ≥ 5. Just under half (25, 46%) of these 'do not attempt cardiopulmonary resuscitation' recommendations were formally suspended at the time of anaesthesia and surgery. One in five of these patients with a 'do not attempt cardiopulmonary resuscitation' recommendation who had a cardiac arrest survived to leave hospital and of the seven patients with documented modified Rankin Scale scores before and after cardiac arrest, four remained the same and three had worse scores. Very few patients who had a pre-existing 'do not attempt cardiopulmonary resuscitation' recommendation had a peri-operative cardiac arrest, and when cardiac arrest did occur, return of spontaneous circulation was achieved in 57%, although > 50% of these patients subsequently died before discharge from hospital.

Peri-operative cardiac arrest in children as reported to the 7th National Audit Project of the Royal College of Anaesthetists.

The 7th National Audit Project of the Royal College of Anaesthetists studied peri-operative cardiac arrest. An activity survey estimated UK paediatric anaesthesia annual caseload as 390,000 cases, 14% of the UK total. Paediatric peri-operative cardiac arrests accounted for 104 (12%) reports giving an incidence of 3 in 10,000 anaesthetics (95%CI 2.2-3.3 per 10,000). The incidence of peri-operative cardiac arrest was highest in neonates (27, 26%), infants (36, 35%) and children with congenital heart disease (44, 42%) and most reports were from tertiary centres (88, 85%). Frequent precipitants of cardiac arrest in non-cardiac surgery included: severe hypoxaemia (20, 22%); bradycardia (10, 11%); and major haemorrhage (9, 8%). Cardiac tamponade and isolated severe hypotension featured prominently as causes of cardiac arrest in children undergoing cardiac surgery or cardiological procedures. Themes identified at review included: inappropriate choices and doses of anaesthetic drugs for intravenous induction; bradycardias associated with high concentrations of volatile anaesthetic agent or airway manipulation; use of atropine in the place of adrenaline; and inadequate monitoring. Overall quality of care was judged by the panel to be good in 64 (62%) cases, which compares favourably with adults (371, 52%). The study provides insight into paediatric anaesthetic practice, complications and peri-operative cardiac arrest.

Cardiac arrest in vascular surgical patients receiving anaesthetic care: an analysis from the 7th National Audit Project (NAP7) of the Royal College of Anaesthetists.

The 7th National Audit Project of the Royal College of Anaesthetists studied peri-operative cardiac arrest in the UK. We report the results of the vascular surgery cohort from the 12-month case registry, from 16 June 2021 to 15 June 2022. Anaesthesia for vascular surgery accounted for 2% of UK anaesthetic caseload and included 69 (8%) reported peri-operative cardiac arrests, giving an estimated incidence of 1 in 670 vascular anaesthetics (95%CI 1 in 520-830). The high-risk nature of the vascular population is reflected by the proportion of patients who were ASA physical status 4 (30, 43%) or 5 (19, 28%); the age of patients (80% aged > 65 y); and that most cardiac arrests (57, 83%) occurred during non-elective surgery. The most common vascular surgical procedures among patients who had a cardiac arrest were: aortic surgery (38, 55%); lower-limb revascularisation (13, 19%); and lower-limb amputation (8, 12%). Among patients having vascular surgery and who had a cardiac arrest, 28 (41%) presented with a ruptured abdominal aortic aneurysm. There were 48 (70%) patients who had died at the time of reporting to NAP7 and 11 (16%) were still in hospital, signifying poorer outcomes compared with the non-vascular surgical cohort. The most common cause of cardiac arrest was major haemorrhage (39, 57%), but multiple other causes reflected the critical illness of the patients and the complexity of surgery. This is the first analysis of the incidence, management and outcomes of peri-operative cardiac arrest during vascular anaesthesia in the UK.

The incidence of potentially serious complications during non-obstetric anaesthetic practice in the United Kingdom: an analysis from the 7th National Audit Project (NAP7) activity survey.

Complications and critical incidents arising during anaesthesia due to patient, surgical or anaesthetic factors, may cause harm themselves or progress to more severe events, including cardiac arrest or death. As part of the 7th National Audit Project of the Royal College of Anaesthetists, we studied a prospective national cohort of unselected patients. Anaesthetists recorded anonymous details of all cases undertaken over 4 days at their site through an online survey. Of 416 hospital sites invited to participate, 352 (85%) completed the survey. Among 24,172 cases, 1922 discrete potentially serious complications were reported during 1337 (6%) cases. Obstetric cases had a high reported major haemorrhage rate and were excluded from further analysis. Of 20,996 non-obstetric cases, 1705 complications were reported during 1150 (5%) cases. Circulatory events accounted for most complications (616, 36%), followed by airway (418, 25%), metabolic (264, 15%), breathing (259, 15%), and neurological (41, 2%) events. A single complication was reported in 851 (4%) cases, two complications in 166 (1%) cases and three or more complications in 133 (1%) cases. In non-obstetric elective surgery, all complications were 'uncommon' (10-100 per 10,000 cases). Emergency (urgent and immediate priority) surgery accounted for 3454 (16%) of non-obstetric cases but 714 (42%) of complications with severe hypotension, major haemorrhage, severe arrhythmias, septic shock, significant acidosis and electrolyte disturbances all being 'common' (100-1000 per 10,000 cases). Based on univariate analysis, complications were associated with: younger age; higher ASA physical status; male sex; increased frailty; urgency and extent of surgery; day of the week; and time of day. These data represent the rates of potentially serious complications during routine anaesthesia care and may be valuable for risk assessment and patient consent.

Peri-operative cardiac arrest: management and outcomes of patients analysed in the 7th National Audit Project of the Royal College of Anaesthetists.

The 7th National Audit Project of the Royal College of Anaesthetists studied peri-operative cardiac arrest in the UK, a topic of importance to patients, anaesthetists and surgeons. We report the results of the 12-month registry phase, from 16 June 2021 to 15 June 2022, focusing on management and outcomes. Among 881 cases of peri-operative cardiac arrest, the initial rhythm was non-shockable in 723 (82%) cases, most commonly pulseless electrical activity. There were 665 (75%) patients who survived the initial event and 384 (52%) who survived to hospital discharge. A favourable functional outcome (based on modified Rankin Scale score) was reported for 249 (88%) survivors. Outcomes varied according to arrest rhythm. The highest rates of survival were seen for bradycardic cardiac arrests with 111 (86%) patients surviving the initial event and 77 (60%) patients surviving the hospital episode. The lowest survival rates were seen for patients with pulseless electrical activity, with 312 (68%) surviving the initial episode and 156 (34%) surviving to hospital discharge. Survival to hospital discharge was worse in patients at the extremes of age with 76 (40%) patients aged > 75 y and 9 (45%) neonates surviving. Hospital survival was also associated with surgical priority, with 175 (88%) elective patients and 176 (37%) non-elective patients surviving to discharge. Outcomes varied with the cause of cardiac arrest, with lower initial survival rates for pulmonary embolism (5, 31%) and bone cement implantation syndrome (9, 45%), and hospital survival of < 25% for pulmonary embolism (0), septic shock (13, 24%) and significant hyperkalaemia (1, 20%). Overall care was rated good in 464 (53%) cases, and 18 (2%) cases had overall care rated as poor. Poor care elements were present in a further 245 (28%) cases. Care before cardiac arrest was the phase most frequently rated as poor (92, 11%) with elements of poor care identified in another 186 (21%) cases. These results describe the management and outcomes of peri-operative cardiac arrest in UK practice for the first time.

Peri-operative cardiac arrest: epidemiology and clinical features of patients analysed in the 7th National Audit Project of the Royal College of Anaesthetists.

The 7th National Audit Project of the Royal College of Anaesthetists studied peri-operative cardiac arrest in the UK, a topic of importance to patients, anaesthetists and surgeons. Here we report the results of the 12-month registry, from 16 June 2021 to 15 June 2022, focusing on epidemiology and clinical features. We reviewed 881 cases of peri-operative cardiac arrest, giving an incidence of 3 in 10,000 anaesthetics (95%CI 3.0-3.5 per 10,000). Incidence varied with patient and surgical factors. Compared with denominator survey activity, patients with cardiac arrest: included more males (56% vs. 42%); were older (median (IQR) age 60.5 (40.5-80.5) vs. 50.5 (30.5-70.5) y), although the age distribution was bimodal, with infants and patients aged > 66 y overrepresented; and were notably more comorbid (73% ASA physical status 3-5 vs. 27% ASA physical status 1-2). The surgical case-mix included more weekend (14% vs. 11%), out-of-hours (19% vs. 10%), non-elective (65% vs. 30%) and major/complex cases (60% vs. 28%). Cardiac arrest was most prevalent in orthopaedic trauma (12%), lower gastrointestinal surgery (10%), cardiac surgery (9%), vascular surgery (8%) and interventional cardiology (6%). Specialities with the highest proportion of cases relative to denominator activity were: cardiac surgery (9% vs. 1%); cardiology (8% vs. 1%); and vascular surgery (8% vs. 2%). The most common causes of cardiac arrest were: major haemorrhage (17%); bradyarrhythmia (9%); and cardiac ischaemia (7%). Patient factors were judged a key cause of cardiac arrest in 82% of cases, anaesthesia in 40% and surgery in 35%.

Predicting severe pain after major surgery: a secondary analysis of the Peri-operative Quality Improvement Programme (PQIP) dataset.

Acute postoperative pain is common, distressing and associated with increased morbidity. Targeted interventions can prevent its development. We aimed to develop and internally validate a predictive tool to pre-emptively identify patients at risk of severe pain following major surgery. We analysed data from the UK Peri-operative Quality Improvement Programme to develop and validate a logistic regression model to predict severe pain on the first postoperative day using pre-operative variables. Secondary analyses included the use of peri-operative variables. Data from 17,079 patients undergoing major surgery were included. Severe pain was reported by 3140 (18.4%) patients; this was more prevalent in females, patients with cancer or insulin-dependent diabetes, current smokers and in those taking baseline opioids. Our final model included 25 pre-operative predictors with an optimism-corrected c-statistic of 0.66 and good calibration (mean absolute error 0.005, p = 0.35). Decision-curve analysis suggested an optimal cut-off value of 20-30% predicted risk to identify high-risk individuals. Potentially modifiable risk factors included smoking status and patient-reported measures of psychological well-being. Non-modifiable factors included demographic and surgical factors. Discrimination was improved by the addition of intra-operative variables (likelihood ratio χ2 496.5, p < 0.001) but not by the addition of baseline opioid data. On internal validation, our pre-operative prediction model was well calibrated but discrimination was moderate. Performance was improved with the inclusion of peri-operative covariates suggesting pre-operative variables alone are not sufficient to adequately predict postoperative pain.

Patient characteristics, anaesthetic workload and techniques in the UK: an analysis from the 7th National Audit Project (NAP7) activity survey.

Detailed contemporary knowledge of the characteristics of the surgical population, national anaesthetic workload, anaesthetic techniques and behaviours are essential to monitor productivity, inform policy and direct research themes. Every 3-4 years, the Royal College of Anaesthetists, as part of its National Audit Projects (NAP), performs a snapshot activity survey in all UK hospitals delivering anaesthesia, collecting patient-level encounter data from all cases under the care of an anaesthetist. During November 2021, as part of NAP7, anaesthetists recorded details of all cases undertaken over 4 days at their site through an online survey capturing anonymous patient characteristics and anaesthetic details. Of 416 hospital sites invited to participate, 352 (85%) completed the activity survey. From these, 24,177 reports were returned, of which 24,172 (99%) were included in the final dataset. The work patterns by day of the week, time of day and surgical specialty were similar to previous NAP activity surveys. However, in non-obstetric patients, between NAP5 (2013) and NAP7 (2021) activity surveys, the estimated median age of patients increased by 2.3 years from median (IQR) of 50.5 (28.4-69.1) to 52.8 (32.1-69.2) years. The median (IQR) BMI increased from 24.9 (21.5-29.5) to 26.7 (22.3-31.7) kg.m-2 . The proportion of patients who scored as ASA physical status 1 decreased from 37% in NAP5 to 24% in NAP7. The use of total intravenous anaesthesia increased from 8% of general anaesthesia cases to 26% between NAP5 and NAP7. Some changes may reflect the impact of the COVID-19 pandemic on the anaesthetic population, though patients with confirmed COVID-19 accounted for only 149 (1%) cases. These data show a rising burden of age, obesity and comorbidity in patients requiring anaesthesia care, likely to impact UK peri-operative services significantly.

The 7th National Audit Project (NAP7) baseline survey of individual anaesthetists: preparedness for and experiences of peri-operative cardiac arrest.

The Royal College of Anaesthetists' 7th National Audit Project baseline survey assessed knowledge, attitudes, practices and experiences of peri-operative cardiac arrests among UK anaesthetists and Anaesthesia Associates. We received 10,746 responses, representing a 71% response rate. In-date training in adult and paediatric advanced life support was reported by 9646 (90%) and 7125 (66%) anaesthetists, respectively. There were 8994 (84%) respondents who were confident in leading a peri-operative cardiac arrest, with males more confident than females, but only 5985 (56%) were confident in leading a debrief and 7340 (68%) communicating with next of kin. In the previous two years, 4806 (46%) respondents had managed at least one peri-operative cardiac arrest, of which 321 (7%) and 189 (4%) of these events involved a child or an obstetric patient, respectively. Respondents estimated the most common causes of peri-operative cardiac arrest to be hypovolaemia, hypoxaemia and cardiac ischaemia, with haemorrhage coming fifth. However, the most common reported causes for the most recently attended peri-operative cardiac arrest were haemorrhage; (927, 20%); anaphylaxis (474, 10%); and cardiac ischaemia (397, 9%). Operating lists or shifts were paused or stopped after 1330 (39%) cardiac arrests and 1693 (38%) respondents attended a debrief, with 'hot' debriefs most common. Informal wellbeing support was relatively common (2458, 56%) and formal support was uncommon (472, 11%). An impact on future care delivery was reported by 196 (4%) anaesthetists, most commonly a negative psychological impact. Management of a peri-operative cardiac arrest during their career was reported by 8654 (85%) respondents. The overall impact on professional life was more often judged positive (2630, 30%) than negative (1961, 23%), but impact on personal life was more often negative.

Organisation of UK hospitals and anaesthetic departments in the treatment of peri-operative cardiac arrest: an analysis from the 7th National Audit Project (NAP7) local co-ordinator baseline survey.

We report the results of the Royal College of Anaesthetists' 7th National Audit Project organisational baseline survey sent to every NHS anaesthetic department in the UK to assess preparedness for treating peri-operative cardiac arrest. We received 199 responses from 277 UK anaesthetic departments, representing a 72% response rate. Adult and paediatric anaesthetic care was provided by 188 (95%) and 165 (84%) hospitals, respectively. There was no paediatric intensive care unit on-site in 144 (87%) hospitals caring for children, meaning transfer of critically ill children is required. Remote site anaesthesia is provided in 182 (92%) departments. There was a departmental resuscitation lead in 113 (58%) departments, wellbeing lead in 106 (54%) and departmental staff wellbeing policy in 81 (42%). A defibrillator was present in every operating theatre suite and in all paediatric anaesthesia locations in 193 (99%) and 149 (97%) departments, respectively. Advanced airway equipment was not available in: every theatre suite in 13 (7%) departments; all remote locations in 103 (57%) departments; and all paediatric anaesthesia locations in 23 (15%) departments. Anaesthetic rooms were the default location for induction of anaesthesia in adults and children in 148 (79%) and 121 (79%) departments, respectively. Annual updates in chest compressions and in defibrillation were available in 149 (76%) and 130 (67%) departments, respectively. Following a peri-operative cardiac arrest, debriefing and peer support programmes were available in 154 (79%) and 57 (29%) departments, respectively. While it is likely many UK hospitals are very well prepared to treat anaesthetic emergencies including cardiac arrest, the survey suggests this is not universal.

Methods of the 7th National Audit Project (NAP7) of the Royal College of Anaesthetists: peri-operative cardiac arrest.

Cardiac arrest in the peri-operative period is rare but associated with significant morbidity and mortality. Current reporting systems do not capture many such events, so there is an incomplete understanding of incidence and outcomes. As peri-operative cardiac arrest is rare, many hospitals may only see a small number of cases over long periods, and anaesthetists may not be involved in such cases for years. Therefore, a large-scale prospective cohort is needed to gain a deep understanding of events leading up to cardiac arrest, management of the arrest itself and patient outcomes. Consequently, the Royal College of Anaesthetists chose peri-operative cardiac arrest as the 7th National Audit Project topic. The study was open to all UK hospitals offering anaesthetic services and had a three-part design. First, baseline surveys of all anaesthetic departments and anaesthetists in the UK, examining respondents' prior peri-operative cardiac arrest experience, resuscitation training and local departmental preparedness. Second, an activity survey to record anonymised details of all anaesthetic activity in each site over 4 days, enabling national estimates of annual anaesthetic activity, complexity and complication rates. Third, a case registry of all instances of peri-operative cardiac arrest in the UK, reported confidentially and anonymously, over 1 year starting 16 June 2021, followed by expert review using a structured process to minimise bias. The definition of peri-operative cardiac arrest was the delivery of five or more chest compressions and/or defibrillation in a patient having a procedure under the care of an anaesthetist. The peri-operative period began with the World Health Organization 'sign-in' checklist or first hands-on contact with the patient and ended either 24 h after the patient handover (e.g. to the recovery room or intensive care unit) or at discharge if this occured earlier than 24 h. These components described the epidemiology of peri-operative cardiac arrest in the UK and provide a basis for developing guidelines and interventional studies.

Determining concentric and eccentric force-velocity profiles during squatting.

PURPOSE: The force-velocity relationship of muscular contraction has been extensively studied. However, previous research has focussed either on isolated muscle or single-joint movements, whereas human movement consists of multi-joint movements (e.g. squatting). Therefore, the purpose of this study was to investigate the force-velocity relationship of isovelocity squatting. METHODS: Fifteen male participants (24 ± 2 years, 79.8 ± 9.1 kg, 177.5 ± 6 cm) performed isovelocity squats on a novel motorised isovelocity device (Kineo Training System) at three concentric (0.25, 0.5, and 0.75 m s-1) and three eccentric velocities (- 0.25, - 0.5, and - 0.75 m s-1). Peak vertical ground reaction forces, that occurred during the isovelocity phase, were collected using dual force plates (2000 Hz) (Kistler, Switzerland). RESULTS: The group mean squat force-velocity profile conformed to the typical in vivo profile, with peak vertical ground reaction forces during eccentric squatting being 9.5 ± 19% greater than isometric (P = 0.037), and occurring between - 0.5 and - 0.75 m s-1. However, large inter-participant variability was identified (0.84-1.62 × isometric force), with some participants being unable to produce eccentric forces greater than isometric. Sub-group analyses could not identify differences between individuals who could/could not produce eccentric forces above isometric, although those who could not tended to be taller. CONCLUSIONS: These finding suggest that variability exists between participants in the ability to generate maximum eccentric forces during squatting, and the magnitude of eccentric increase above isometric cannot be predicted solely based on a concentric assessment. Therefore, an assessment of eccentric capabilities may be required prior to prescribing eccentric-specific resistance training.

Persisting Symptomatic Severe Secondary Mitral Regurgitation in Heart Failure Patients.

Aims We aimed to assess the rate of persisting severe symptomatic secondary mitral regurgitation (MR) in a newly diagnosed heart failure (HF) population following optimisation of guideline directed medical therapy (GDMT), cardiac resynchronisation therapy (CRT) and revascularisation. Methods We assessed all new patients referred to our hospital group's HF clinics. We retrospectively reviewed these patients at HF clinic enrolment, HF programme completion, as well as most recent follow up. Results Of the 242 new patients referred to our HF clinics, there were 10 patients (4.1%) who had either persisting symptomatic severe secondary MR at HF programme completion, or had undergone mitral valve surgery. There were no percutaneous mitral valve repairs at the time of these patients' referrals. The rates of ACE/ARB/ARNI, BB and MRA use were 87.8%, 94.1%, and 49.8% in those with mid ranged, or reduced ejection fraction. The rates of ICD and CRT therapy were 15.1% and 4.4% at follow up. Patients with severe MR had higher time adjusted rates of death or hospitalization for heart failure. Conclusion In a well-treated newly diagnosed HF population, repeat assessment at HF programme completion suggests 4.1% of patients have a persisting indication for percutaneous mitral valve repair based on persisting severe symptomatic secondary MR.

Routinely collected data and patient-centred research in anaesthesia and peri-operative care: a narrative review.

Randomised controlled trials are the gold standard in clinical research, but remain rare due to their expense and a perceived lack of 'real-world' applicability. At the same time, there has been an exponential increase in routinely collected data which presents opportunities for audit, quality improvement, adverse event reporting and more efficient clinical research. Registry-based research benefits from reduced cost, large sample size and real-world applicability, with methodological developments, particularly registry-based randomised controlled trials and causal inference techniques, showing promise. Limitations include data quality and validity, the need for data linkage, the restrictions of fixed data fields, regulatory barriers, and privacy and security concerns. However, the principal factor hampering current efforts is a lack of anaesthesia-specific datasets in the UK and the fact that most surgical registries do not collect any anaesthetic data. This presents an opportunity for anaesthetists, through enhanced engagement and collaboration, to influence and improve the design of these datasets and increase the value and volume of data collected. Better datasets, coupled with a growing appreciation of new analysis methodologies, would allow significant progress towards realising the potential of routinely collected data for patient benefit. At the same time, work should begin on the development of a minimum dataset for anaesthesia to underpin new data sharing networks and, ideally, a national registry of anaesthesia.

Mortality in patients admitted to intensive care with COVID-19: an updated systematic review and meta-analysis of observational studies.

The COVID-19 pandemic continues to cause critical illness and deaths internationally. Up to 31 May 2020, mortality in patients admitted to intensive care units (ICU) with COVID-19 was 41.6%. Since then, changes in therapeutics and management may have improved outcomes. Also, data from countries affected later in the pandemic are now available. We searched MEDLINE, Embase, PubMed and Cochrane databases up to 30 September 2020 for studies reporting ICU mortality among adult patients with COVID-19 and present an updated systematic review and meta-analysis. The primary outcome measure was death in intensive care as a proportion of completed ICU admissions, either through discharge from intensive care or death. We identified 52 observational studies including 43,128 patients, and first reports from the Middle East, South Asia and Australasia, as well as four national or regional registries. Reported mortality was lower in registries compared with other reports. In two regions, mortality differed significantly from all others, being higher in the Middle East and lower in a single registry study from Australasia. Although ICU mortality (95%CI) was lower than reported in June (35.5% (31.3-39.9%) vs. 41.6% (34.0-49.7%)), the absence of patient-level data prevents a definitive evaluation. A lack of standardisation of reporting prevents comparison of cohorts in terms of underlying risk, severity of illness or outcomes. We found that the decrease in ICU mortality from COVID-19 has reduced or plateaued since May 2020 and note the possibility of some geographical variation. More standardisation in reporting would improve the ability to compare outcomes from different reports.