Anaesthesia associates' clinical activity, case mix, supervision and involvement in peri-operative cardiac arrest: analysis from the 7th National Audit Project.

BACKGROUND: We analysed the clinical practice of anaesthesia associates in the UK, as reported to the 7th National Audit Project of the Royal College of Anaesthetists, and compared these with medically qualified anaesthetists. METHODS: We included data from our baseline survey, activity survey and case registry as with other reports from the project. RESULTS: Among 197 departments of anaesthesia, 52 (26%) employed anaesthesia associates. Of 10,009 responding anaesthesia care providers, 71 (< 1%) were anaesthesia associates, of whom 33 (47%) reporting working nights or weekends (compared with 97% of medically qualified anaesthetists in training and > 90% of consultants). Anaesthesia associates reported less training and confidence in managing peri-operative cardiac arrest and its aftermath compared with medically qualified anaesthetists. Anaesthesia associates were less directly involved in the management and the aftermath of peri-operative cardiac arrest than medically qualified anaesthetists, and the psychological impacts on professional and personal life appeared to be less. Among 24,172 cases, anaesthesia associates attended 432 (2%) and were the senior anaesthesia care provider in 63 (< 1%), with indirect supervision in 27 (43%). Anaesthesia associates worked predominantly in a small number of surgical specialties during weekdays and working daytime hours. Complication rates were low in cases managed by anaesthesia associates, likely reflecting case mix. However, activity and registry case mix data show anaesthesia associates do manage high-risk cases (patients who are older, comorbid, obese and frail) with the potential for serious complications. Registry cases included higher risk cases with respect to the clinical setting and patient factors. CONCLUSION: Anaesthesia associates work in enhanced roles, relative to the scope of practice at qualification agreed by organisations. Recent changes mean the Royal College of Anaesthetists and Association of Anaesthetists do not currently support an enhanced scope of practice.

Advanced life support interventions during intra-operative cardiac arrest among adults as reported to the 7th National Audit Project of the Royal College of Anaesthetists.

BACKGROUND: Few existing resuscitation guidelines include specific reference to intra-operative cardiac arrest, but its optimal treatment is likely to require some adaptation of standard protocols. METHODS: We analysed data from the 7th National Audit Project of the Royal College of Anaesthetists to determine the incidence and outcome from intra-operative cardiac arrest and to summarise the advanced life support interventions reported as being used by anaesthetists. RESULTS: In the baseline survey, > 50% of anaesthetists responded that they would start chest compressions when the non-invasive systolic pressure was < 40-50 mmHg. Of the 881 registry patients, 548 were adult patients (aged > 18 years) having non-obstetric procedures under the care of an anaesthetist, and who had arrested during anaesthesia (from induction to emergence). Sustained return of spontaneous circulation was achieved in 425 (78%) patients and 338 (62%) were alive at the time of reporting. In the 365 patients with pulseless electrical activity or bradycardia, adrenaline was given as a 1 mg bolus in 237 (65%). A precordial thump was used in 14 (3%) patients, and although this was associated with return of spontaneous circulation at the next rhythm check in almost three-quarters of patients, in only one of these was the initial rhythm shockable. Calcium (gluconate or chloride) and 8.4% sodium bicarbonate were given to 51 (9%) and 25 (5%) patients, but there were specific indications for these treatments in less than half of the patients. A thrombolytic drug was given to 5 (1%) patients, and extracorporeal cardiopulmonary resuscitation was used in 9 (2%) of which eight occurred during cardiac procedures. CONCLUSIONS: The specific characteristics of intra-operative cardiac arrest imply that its optimal treatment requires modifications to standard advanced life support guidelines.

The influence of mode of anaesthesia on perioperative outcomes in people with hip fracture: a prospective cohort study from the National Hip Fracture Database for England, Wales and Northern Ireland.

BACKGROUND: Delirium is common after hip fracture surgery, affecting up to 50% of patients. The incidence of delirium may be influenced by mode and conduct of anaesthesia. We examined the effect of spinal anaesthesia (with and without sedation) compared with general anaesthesia on early outcomes following hip fracture surgery, including delirium. METHODS: We used prospective data on 107,028 patients (2018 to 2019) from the National Hip Fracture Database, which records all hip fractures in patients aged 60 years and over in England, Wales and Northern Ireland. Patients were grouped by anaesthesia: general (58,727; 55%), spinal without sedation (31,484; 29%), and spinal with sedation (16,817; 16%). Outcomes (4AT score on post-operative delirium screening; mobilisation day one post-operatively; length of hospital stay; discharge destination; 30-day mortality) were compared between anaesthetic groups using multivariable logistic and linear regression models. RESULTS: Compared with general anaesthesia, spinal anaesthesia without sedation (but not spinal with sedation) was associated with a significantly reduced risk of delirium (odds ratio (OR)=0.95, 95% confidence interval (CI)=0.92-0.98), increased likelihood of day one mobilisation (OR=1.06, CI=1.02-1.10) and return to original residence (OR=1.04, CI=1.00-1.07). Spinal without sedation (p<0.001) and spinal with sedation (p=0.001) were both associated with shorter hospital stays compared with general anaesthesia. No differences in mortality were observed between anaesthetic groups. CONCLUSIONS: Spinal and general anaesthesia achieve similar outcomes for patients with hip fracture. However, this equivalence appears to reflect improved perioperative outcomes (including a reduced risk of delirium, increased likelihood of mobilisation day one post-operatively, shorter length of hospital stay and improved likelihood of returning to previous residence on discharge) among the sub-set of patients who received spinal anaesthesia without sedation. The role and effect of sedation should be studied in future trials of hip fracture patients undergoing spinal anaesthesia.

Individualised care or anaesthetist preference: an uncomfortable question.

There is widespread variation in how anaesthesia is provided to individual patients even for the same types of surgery. This variation exists within departments, between hospitals, and between countries. Patient and surgical factors are often cited as a justification for variation. Local and national norms, guidance, and standards, and the positive or negative roles of key opinion leaders likely all play a part. Although clinicians may disagree where the line falls between warranted and unwarranted variations, at least some of this variation is down to anaesthetist preference, not individualised patient care.

Preoperative inflammatory mediators and postoperative delirium: systematic review and meta-analysis.

BACKGROUND: Postoperative delirium has eluded attempts to define its complex aetiology and describe specific risk factors. The role of neuroinflammation as a risk factor, determined by measuring blood levels of preoperative 'innate' inflammatory mediator levels, has been investigated. However, results have been conflicting. We conducted a systematic review and meta-analysis of the evidence on associations between preoperative blood levels of inflammatory mediators and postoperative delirium in the older person. Influence of type of surgery was also assessed. METHODS: Original, low risk of bias studies, published in peer-reviewed journals, which fulfilled the eligibility criteria were included. Seventeen articles fulfilled study criteria. Data extraction, synthesis, and risk of bias analysis were guided by Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) and quality in prognostic studies guidelines. Meta-analyses used a random-effects model. Inflammatory mediators included C-reactive protein, interleukin-6, -8, and -10, tumour necrosis factor-α, insulin-like growth factor-1, cortisol, and neopterin. Surgical groups were cardiac, noncardiac, and hip fracture. RESULTS: Higher preoperative interleukin-6 was associated with postoperative delirium with a standardised mean difference (95% confidence interval) of 0.33 (0.11-0.56) and P=0.003. Higher neopterin was also associated with postoperative delirium. CONCLUSIONS: The association of preoperative blood levels of inflammatory mediators with postoperative delirium may be influenced by the type of surgery and the specific mediator. The potential modulating effect of type of surgery, intrinsic brain vulnerability, and the complex interactions between inflammatory mediators and binding proteins will need to be considered in future studies. CLINICAL TRIAL REGISTRATION: CRD42019159471 (PROSPERO).

A restrictive versus liberal transfusion strategy to prevent myocardial injury in patients undergoing surgery for fractured neck of femur: a feasibility randomised trial (RESULT-NOF).

BACKGROUND: The optimum transfusion strategy in patients with fractured neck of femur is uncertain, particularly if there is coexisting cardiovascular disease. METHODS: We conducted a prospective, single-centre, randomised feasibility trial of two transfusion strategies. We randomly assigned patients undergoing surgery for fractured neck of femur to a restrictive (haemoglobin, 70-90 g L-1) or liberal (haemoglobin, 90-110 g L-1) transfusion strategy throughout their hospitalisation. Feasibility outcomes included: enrolment rate, protocol compliance, difference in haemoglobin, and blood exposure. The primary clinical outcome was myocardial injury using troponin estimations. Secondary outcomes included major adverse cardiac events, postoperative complications, duration of hospitalisation, mortality, and quality of life. RESULTS: We enrolled 200 (22%) of 907 eligible patients, and 62 (31%) showed decreased haemoglobin (to 90 g L-1 or less) and were thus exposed to the intervention. The overall protocol compliance was 81% in the liberal group and 64% in the restrictive group. Haemoglobin concentrations were similar preoperatively and at postoperative day 1 but lower in the restrictive group on day 2 (mean difference [MD], 7.0 g L-1; 95% confidence interval [CI], 1.6-12.4). Lowest haemoglobin within 30 days/before discharge was lower in the restrictive group (MD, 5.3 g L-1; 95% CI, 1.7-9.0). Overall, 58% of patients in the restrictive group received no transfusion compared with 4% in the liberal group (difference in proportion, 54.5%; 95% CI, 36.8-72.2). The proportion with the primary clinical outcome was 14/26 (54%, liberal) vs 24/34 (71%, restrictive), and the difference in proportion was -16.7% (95% CI, -41.3 to 7.8; P=0.18). CONCLUSION: A clinical trial of two transfusion strategies in hip fracture with a clinically relevant cardiac outcome is feasible. CLINICAL TRIAL REGISTRATION: NCT03407573.

Acute and chronic kidney disease in elderly patients with hip fracture: prevalence, risk factors and outcome with development and validation of a risk prediction model for acute kidney injury.

BACKGROUND: Hip fracture is a common injury in older people with a high rate of postoperative morbidity and mortality. This patient group is also at high risk of acute kidney injury (AKI) and chronic kidney disease (CKD), but little is known of the impact of kidney disease on outcome following hip fracture. METHODS: An observational cohort of consecutive patients with hip fracture in a large UK secondary care hospital. Predictive modelling of outcomes using development and validation datasets. Inclusion: all patients admitted with hip fracture with sufficient serum creatinine measurements to define acute kidney injury. Main outcome measures - development of acute kidney injury during admission; mortality (in hospital, 30-365 day and to follow-up); length of hospital stay. RESULTS: Data were available for 2848 / 2959 consecutive admissions from 2007-2011; 776 (27.2%) male. Acute kidney injury occurs in 24%; development of acute kidney injury is independently associated with male sex (OR 1.48 (1.21 to 1.80), premorbid chronic kidney disease stage 3B or worse (OR 1.52 (1.19 to 1.93)), age (OR 3.4 (2.29 to 5.2) for >85 years) and greater than one major co-morbidities (OR 1.61 (1.34 to 1.93)). Acute kidney injury of any stage is associated with an increased hazard of death, and increased length of stay (Acute kidney injury: 19.1 (IQR 13 to 31) days; no acute kidney injury 15 (11 to 23) days). A simplified predictive model containing Age, CKD stage (3B-5), two or more comorbidities, and male sex had an area under the ROC curve of 0.63 (0.60 to 0.67). CONCLUSIONS: Acute kidney injury following hip fracture is common and associated with worse outcome and greater hospital length of stay. With the number of people experiencing hip fracture predicted to rise, recognition of risk factors and optimal perioperative management of acute kidney injury will become even more important.