pRotective vEntilation with veno-venouS lung assisT in respiratory failure: A protocol for a multicentre randomised controlled trial of extracorporeal carbon dioxide removal in patients with acute hypoxaemic respiratory failure.

One of the few interventions to demonstrate improved outcomes for acute hypoxaemic respiratory failure is reducing tidal volumes when using mechanical ventilation, often termed lung protective ventilation. Veno-venous extracorporeal carbon dioxide removal (vv-ECCO2R) can facilitate reducing tidal volumes. pRotective vEntilation with veno-venouS lung assisT (REST) is a randomised, allocation concealed, controlled, open, multicentre pragmatic trial to determine the clinical and cost-effectiveness of lower tidal volume mechanical ventilation facilitated by vv-ECCO2R in patients with acute hypoxaemic respiratory failure. Patients requiring intubation and mechanical ventilation for acute hypoxaemic respiratory failure will be randomly allocated to receive either vv-ECCO2R and lower tidal volume mechanical ventilation or standard care with stratification by recruitment centre. There is a need for a large randomised controlled trial to establish whether vv-ECCO2R in acute hypoxaemic respiratory failure can allow the use of a more protective lung ventilation strategy and is associated with improved patient outcomes.

A multicentre snapshot study of the incidence of serious procedural complications secondary to central venous catheterisation.

Despite the high number of central venous access devices inserted annually, there are limited data on the incidence of the associated procedural complications, many of which carry substantial clinical risk. This point was highlighted in the recently published Association of Anaesthetists of Great Britain and Ireland 'Safe vascular access 2016' guidelines. This trainee-led snapshot study aimed to identify the number of central venous catheter insertions and the incidence of serious complications across multiple hospital sites within a fixed two-week period. Secondary aims were to identify the availability of resources and infrastructure to facilitate safe central venous catheter insertion and management of potential complications. Fifteen hospital sites participated, completing an initial resource survey and daily identification of all adult central venous catheter insertions, with subsequent review of any complications detected. A total of 487 central venous catheter insertions were identified, of which 15 (3.1%) were associated with a significant procedural complication. The most common complication was failure of insertion, which occurred in seven (1.4%) cases. Facilities to enable safer central venous catheter insertion and manage complications varied widely between hospitals, with little evidence of standardisation of guidelines or protocols.

Misplaced central venous catheters: applied anatomy and practical management.

Large numbers of central venous catheters (CVCs) are placed each year and misplacement occurs frequently. This review outlines the normal and abnormal anatomy of the central veins in relation to the placement of CVCs. An understanding of normal and variant anatomy enables identification of congenital and acquired abnormalities. Embryological variations such as a persistent left-sided superior vena cava are often diagnosed incidentally only after placement of a CVC, which is seen to take an abnormal course on X-ray. Acquired abnormalities such as stenosis or thrombosis of the central veins can be problematic and can present as a failure to pass a guidewire or catheter or complications after such attempts. Catheters can also be misplaced outside veins in a patient with otherwise normal anatomy with potentially disastrous consequences. We discuss the possible management options for these patients including the various imaging techniques used to verify correct or incorrect catheter placement and the limitations of each. If the course of a misplaced catheter can be correctly identified as not lying within a vulnerable structure then it can be safely removed. If the misplaced catheter is lying within or traversing large and incompressible arteries or veins, it should not be removed before consideration of what is likely to happen when it is removed. Advice and further imaging should be sought, typically in conjunction with interventional radiology or vascular surgery. With regard to misplaced CVCs, in the short term, a useful aide memoir is: 'if in doubt, don't take it out'.

Ultrasound-guided infraclavicular axillary vein cannulation: a useful alternative to the internal jugular vein.

BACKGROUND: Ultrasound (US) guidance reduces complications and increases accuracy during internal jugular vein (IJV) cannulation. The subclavian vein (SCV) is popular but is less amenable to US guidance. The axillary vein (AxV), a direct continuation of the SCV, is an alternative, but to date, experience with US is limited to small case series. METHODS: Retrospective procedural data were collected on 2586 sequential patients referred for insertion of tunnelled central venous access at a UK tertiary centre from 2004 to 2011. RESULTS: A total of 99.8% of patients tolerated the procedure with local anaesthesia ± sedation; six patients had general anaesthesia. Twenty-six (1%) patients had uncorrected coagulopathy or thrombocytopenia. A total of 2572 (99.5%) of patients were cannulated successfully: right AxV 1644 cases, left AxV 279, right IJV 547, left IJV 89, other techniques 13, and 14 (0.5%) cases failed. The initial site chosen was successful in 96%. In patients who previously underwent long-term cannulation, 93.3% of lines were sited easily. Forty-eight (1.9%) procedural complications occurred. CONCLUSIONS: In this large analysis of US-guided central venous access in a complex patient group, the majority of patients were cannulated successfully and safely. The subset of patients undergoing AxV cannulation demonstrated a low rate of complications. The AxV route of access appears to be a safe and effective alternative to the IJV.

Nitrous oxide exposure does not seem to be associated with increased mortality, stroke, and myocardial infarction: a non-randomized subgroup analysis of the General Anaesthesia compared with Local Anaesthesia for carotid surgery (GALA) trial.

BACKGROUND: Nitrous oxide has been associated with increased vascular risk in the perioperative period. Here, we conducted a secondary analysis of the GALA trial to ascertain the impact of nitrous oxide on outcomes after carotid surgery under general anaesthesia (GA). METHODS: One thousand seven hundred and seventy-three patients underwent GA, but 158 patients were excluded from this analysis as nitrous oxide use was unknown. The decision to use nitrous oxide was at the discretion of the anaesthetist and was not randomized. Six hundred and seventy-one patients received nitrous oxide and 944 patients did not. Logistic regression was used to analyse the same primary outcome as the original trial (risk of death, stroke, or myocardial infarction within 30 days of the operation). RESULTS: Patients who received nitrous oxide were more likely to have had coronary artery disease, peripheral vascular disease, and atrial fibrillation (all P<0.05). Overall, there were 35 (5.2%) primary outcome events in patients receiving nitrous oxide compared with 44 (4.7%) in those who did not [relative risk 1.12, 95% confidence interval (CI: 0.73, 1.73); P=0.63]. The adjustment for the imbalanced baseline variables using logistic regression reduced the point estimate of harm for nitrous oxide [adjusted odds ratio 1.09, 95% CI (0.68, 1.74); P=0.73]. CONCLUSIONS: Given the greater prevalence of vascular risk factors in the nitrous oxide group and the lack of any definite effect on the primary outcome measure, these data do not support a clinically meaningful adverse effect of nitrous oxide on our composite outcome in patients undergoing carotid surgery.

Quality and outcomes in anaesthesia: lessons from litigation.

Healthcare litigation in the UK continues to grow at an alarming rate, with claims against anaesthetists and critical care physicians increasing each year. This has led to a huge financial burden for the taxpayer and a sharp increase in professional indemnity fees for individual doctors. Although such litigation should provide valuable information to educate practitioners and reduce future similar claims, there appear to be significant barriers preventing important lessons from being learned. Detailed learning opportunities are available only to the healthcare providers being sued or the expert witnesses employed to analyse the claims. Most practitioners have to rely on indemnifiers' case reports, closed-claim analyses, and ad hoc publications for information. In this review, we suggest ways in which important lessons from litigation could be brought to the attention of all clinicians. Currently, most clinicians are unable to determine whether key components of their practice such as consent, clinical decision-making, and documentation are of an acceptable standard for legal scrutiny. By reporting outcomes of Coroners' inquests, clinical and criminal negligence cases, and referrals to the General Medical Council, it would be hoped that more explicit standards of performance could be derived. Ultimately, this may not only improve patient safety, but protect practitioners from unjustifiable claims. Finally, given the critical importance of experts in the above process, we believe that a system for professional registration and regulation should be explored to ensure that they offer accurate, representative, and unbiased opinions and have the appropriate expertise in the subject matter to be analysed.

Influenza A-induced rhabdomyolysis and acute kidney injury complicated by posterior reversible encephalopathy syndrome.

We report a case of Influenza A-induced rhabdomyolysis causing acute kidney injury in a young adult female who required invasive ventilation and renal replacement therapy. This case was further complicated by posterior reversible encephalopathy syndrome. Although this represents an extremely rare neurological complication of Influenza A infection, an appreciation of the condition and its management is important, given the high numbers of critically ill patients recently affected by H1N1 Influenza A in intensive care units in the UK.

Cost-effectiveness analysis of general anaesthesia versus local anaesthesia for carotid surgery (GALA Trial).

BACKGROUND: Health outcomes and costs are both important when deciding whether general (GA) or local (LA) anaesthesia should be used during carotid endarterectomy. The aim of this study was to assess the cost-effectiveness of carotid endarterectomy under LA or GA in patients with symptomatic or asymptomatic carotid stenosis for whom surgery was advised. METHODS: Using patient-level data from a large, multinational, randomized controlled trial (GALA Trial) time free from stroke, myocardial infarction or death, and costs incurred were evaluated. The cost-effectiveness outcome was incremental cost per day free from an event, within a time horizon of 30 days. RESULTS: A patient undergoing carotid endarterectomy under LA incurred fewer costs (mean difference pound178) and had a slightly longer event-free survival (difference 0.16 days, but the 95 per cent confidence limits around this estimate were wide) compared with a patient who had GA. Existing uncertainty did not have a significant impact on the decision to adopt LA, over a wide range of willingness-to-pay values. CONCLUSION: If cost-effectiveness was considered in the decision to adopt GA or LA for carotid endarterectomy, given the evidence provided by this study, LA is likely to be the favoured treatment for patients for whom either anaesthetic approach is clinically appropriate.

General anaesthesia versus local anaesthesia for carotid surgery (GALA): a multicentre, randomised controlled trial.

BACKGROUND: The effect of carotid endarterectomy in lowering the risk of stroke ipsilateral to severe atherosclerotic carotid-artery stenosis is offset by complications during or soon after surgery. We compared surgery under general anaesthesia with that under local anaesthesia because prediction and avoidance of perioperative strokes might be easier under local anaesthesia than under general anaesthesia. METHODS: We undertook a parallel group, multicentre, randomised controlled trial of 3526 patients with symptomatic or asymptomatic carotid stenosis from 95 centres in 24 countries. Participants were randomly assigned to surgery under general (n=1753) or local (n=1773) anaesthesia between June, 1999 and October, 2007. The primary outcome was the proportion of patients with stroke (including retinal infarction), myocardial infarction, or death between randomisation and 30 days after surgery. Analysis was by intention to treat. The trial is registered with Current Control Trials number ISRCTN00525237. FINDINGS: A primary outcome occurred in 84 (4.8%) patients assigned to surgery under general anaesthesia and 80 (4.5%) of those assigned to surgery under local anaesthesia; three events per 1000 treated were prevented with local anaesthesia (95% CI -11 to 17; risk ratio [RR] 0.94 [95% CI 0.70 to 1.27]). The two groups did not significantly differ for quality of life, length of hospital stay, or the primary outcome in the prespecified subgroups of age, contralateral carotid occlusion, and baseline surgical risk. INTERPRETATION: We have not shown a definite difference in outcomes between general and local anaesthesia for carotid surgery. The anaesthetist and surgeon, in consultation with the patient, should decide which anaesthetic technique to use on an individual basis. FUNDING: The Health Foundation (UK) and European Society of Vascular Surgery.

An investigation into the length of standard tracheostomy tubes in critical care patients.

A number of problems have been reported with the use of standard length tracheostomy tubes in adult critical care patients. We measured the depth from the skin surface to the tracheal wall and the angle of the tracheal stoma during percutaneous tracheostomy. In vitro measurements were also performed on standard tracheostomy tubes. Comparison of in vivo and in vitro dimensions demonstrated that standard length tracheostomy tubes are too short for the average critical care patient. We recommend that both the stomal and intratracheal lengths should be made longer by approximately 1 cm and tubes should be redesigned to an angle of 110-120 degrees to allow optimal tracheal placement.