Showing papers in "BJA: British Journal of Anaesthesia in 2012"

High STOP-Bang score indicates a high probability of obstructive sleep apnoea

Abstract: Background The STOP-Bang questionnaire is used to screen patients for obstructive sleep apnoea (OSA). We evaluated the association between STOP-Bang scores and the probability of OSA. Methods After Institutional Review Board approval, patients who visited the preoperative clinics for a scheduled inpatient surgery were approached for informed consent. Patients answered STOP questionnaire and underwent either laboratory or portable polysomnography (PSG). PSG recordings were scored manually. The BMI, age, neck circumference, and gender (Bang) were documented. Over 4 yr, 6369 patients were approached and 1312 (20.6%) consented. Of them, 930 completed PSG, and 746 patients with complete data on PSG and STOP-Bang questionnaire were included for data analysis. Results The median age of 746 patients was 60 yr, 49% males, BMI 30 kg m−2, and neck circumference 39 cm. OSA was present in 68.4% with 29.9% mild, 20.5% moderate, and 18.0% severe OSA. For a STOP-Bang score of 5, the odds ratio (OR) for moderate/severe and severe OSA was 4.8 and 10.4, respectively. For STOP-Bang 6, the OR for moderate/severe and severe OSA was 6.3 and 11.6, respectively. For STOP-Bang 7 and 8, the OR for moderate/severe and severe OSA was 6.9 and 14.9, respectively. The predicted probabilities for moderate/severe OSA increased from 0.36 to 0.60 as the STOP-Bang score increased from 3 to 7 and 8. Conclusions In the surgical population, a STOP-Bang score of 5–8 identified patients with high probability of moderate/severe OSA. The STOP-Bang score can help the healthcare team to stratify patients for unrecognized OSA, practice perioperative precautions, or triage patients for diagnosis and treatment.

Revised Starling equation and the glycocalyx model of transvascular fluid exchange: an improved paradigm for prescribing intravenous fluid therapy

Abstract: Summary I.V. fluid therapy does not result in the extracellular volume distribution expected from Starling's original model of semi-permeable capillaries subject to hydrostatic and oncotic pressure gradients within the extracellular fluid. Fluid therapy to support the circulation relies on applying a physiological paradigm that better explains clinical and research observations. The revised Starling equation based on recent research considers the contributions of the endothelial glycocalyx layer (EGL), the endothelial basement membrane, and the extracellular matrix. The characteristics of capillaries in various tissues are reviewed and some clinical corollaries considered. The oncotic pressure difference across the EGL opposes, but does not reverse, the filtration rate (the ‘no absorption' rule) and is an important feature of the revised paradigm and highlights the limitations of attempting to prevent or treat oedema by transfusing colloids. Filtered fluid returns to the circulation as lymph. The EGL excludes larger molecules and occupies a substantial volume of the intravascular space and therefore requires a new interpretation of dilution studies of blood volume and the speculation that protection or restoration of the EGL might be an important therapeutic goal. An explanation for the phenomenon of context sensitivity of fluid volume kinetics is offered, and the proposal that crystalloid resuscitation from low capillary pressures is rational. Any potential advantage of plasma or plasma substitutes over crystalloids for volume expansion only manifests itself at higher capillary pressures.

Evidence-based analysis of risk factors for postoperative nausea and vomiting

Abstract: Background In assessing a patient's risk for postoperative nausea and vomiting (PONV), it is important to know which risk factors are independent predictors, and which factors are not relevant for predicting PONV. Methods We conducted a systematic review of prospective studies (n>500 patients) that applied multivariate logistic regression analyses to identify independent predictors of PONV. Odds ratios (ORs) of individual studies were pooled to calculate a more accurate overall point estimate for each predictor. Results We identified 22 studies (n=95 154). Female gender was the strongest patient-specific predictor (OR 2.57, 95% confidence interval 2.32–2.84), followed by the history of PONV/motion sickness (2.09, 1.90–2.29), non-smoking status (1.82, 1.68–1.98), history of motion sickness (1.77, 1.55–2.04), and age (0.88 per decade, 0.84–0.92). The use of volatile anaesthetics was the strongest anaesthesia-related predictor (1.82, 1.56–2.13), followed by the duration of anaesthesia (1.46 h−1, 1.30–1.63), postoperative opioid use (1.39, 1.20–1.60), and nitrous oxide (1.45, 1.06–1.98). Evidence for the effect of type of surgery is conflicting as reference groups differed widely and funnel plots suggested significant publication bias. Evidence for other potential risk factors was insufficient (e.g. preoperative fasting) or negative (e.g. menstrual cycle). Conclusions The most reliable independent predictors of PONV were female gender, history of PONV or motion sickness, non-smoker, younger age, duration of anaesthesia with volatile anaesthetics, and postoperative opioids. There is no or insufficient evidence for a number of commonly held factors, such as preoperative fasting, menstrual cycle, and surgery type, and using these factors may be counterproductive in assessing a patient's risk for PONV.

Meta-analysis of the association between obstructive sleep apnoea and postoperative outcome

Abstract: Results. Thirteen studies were included in the final analysis (n¼3942). OSA was associated with significantly higher odds of any postoperative cardiac events [45/1195 (3.76%) vs 24/1420 (1.69%); odds ratio (OR) 2.07; 95% confidence interval (CI) 1.23‐3.50, P¼0.007] and ARF [33/ 1680 (1.96%) vs 24/3421 (0.70%); OR 2.43, 95% CI 1.34‐4.39, P¼0.003]. Effects were not heterogeneous for these outcomes (I 2 ¼0‐15%, P.0.3). OSA was also significantly associated with higher odds of desaturation [189/1764 (10.71%) vs 105/1881 (5.58%); OR 2.27, 95% CI 1.20‐4.26, P¼0.01] and ICU transfer [105/2062 (5.09%) vs 58/3681 (1.57%), respectively; OR 2.81, 95% CI 1.46‐5.43, P¼0.002]. Both outcomes showed a significant degree of heterogeneity of the effect among studies (I 2 ¼57‐68%, P,0.02). Subgroup analyses had similar conclusions as main analyses. Conclusions. The incidence of postoperative desaturation, respiratory failure, postoperative

Complications and failure of airway management

Abstract: Airway management complications causing temporary patient harm are common, but serious injury is rare. Because most airways are easy, most complications occur in easy airways: these complications can and do lead to harm and death. Because these events are rare, most of our learning comes from large litigation and critical incident databases that help identify patterns and areas where care can be improved: but both have limitations. The recent 4th National Audit Project of the Royal College of Anaesthetists and Difficult Airway Society provides important detailed information and our best estimates of the incidence of major airway complications. A significant proportion of airway complications occur in Intensive Care Units and Emergency Departments, and these more frequently cause patient harm/death and are associated with suboptimal care. Hypoxia is the commonest cause of airway-related deaths. Obesity markedly increases risk of airway complications. Pulmonary aspiration remains the leading cause of airway-related anaesthetic deaths, most cases having identifiable risk factors. Unrecognized oesophageal intubation is not of only historical interest and is entirely avoidable. All airway management techniques fail and prediction scores are rather poor, so many failures are unanticipated. Avoidance of airway complications requires institutional and individual preparedness, careful assessment, good planning and judgement, good communication and teamwork, knowledge and use of a range of techniques and devices, and a willingness to stop performing techniques when they are failing. Analysis of major airway complications identifies areas where practice is suboptimal; research to improve understanding, prevention, and management of such complications remains an anaesthetic priority.

Variations in mortality after emergency laparotomy: the first report of the UK Emergency Laparotomy Network

Abstract: Results. Data from 1853 patients were collected from 35 NHS hospitals. The unadjusted 30 day mortality was 14.9% for all patients and 24.4% in patients aged 80 or over. There was a wide variation between units in terms of the proportion of cases subject to key interventions that may affect outcomes. The presence of a consultant surgeon in theatre varied between 40.6% and 100% of cases, while a consultant anaesthetist was present in theatre for 25‐ 100% of cases. Goal-directed fluid management was used in 0‐63% of cases. Between 0% and 68.9% of the patients returned to the ward (level one) after surgery, and between 9.7% and 87.5% were admitted to intensive care (level three). Mortality rates varied from 3.6% to 41.7%. Conclusions. This study confirms that emergency laparotomy in the UK carries a high mortality. The variation in clinical management and outcomes indicates the need for a national quality improvement programme.

Failed epidural: causes and management

Abstract: Summary. Failed epidural anaesthesia or analgesia is more frequent than generally recognized. We review the factors known to influence the success rate of epidural anaesthesia. Reasons for an inadequate epidural block include incorrect primary placement, secondary migration of a catheter after correct placement, and suboptimal dosing of local anaesthetic drugs. For catheter placement, the loss of resistance using saline has become the most widely used method. Patient positioning, the use of a midline or paramedian approach, and the method used for catheter fixation can all influence the success rate. When using equipotent doses, the difference in clinical effect between bupivacaine and the newer isoforms levobupivacaine and ropivacaine appears minimal. With continuous infusion, dose is the primary determinant of epidural anaesthesia quality, with volume and concentration playing a lesser role. Addition of adjuvants, especially opioids and epinephrine, may substantially increase the success rate of epidural analgesia. Adjuvant opioids may have a spinal or supraspinal action. The use of patientcontrolled epidural analgesia with background infusion appears to be the best method for postoperative analgesia.

Comparison of thromboelastometry (ROTEM®) with standard plasmatic coagulation testing in paediatric surgery

Abstract: Background Thromboelastometry (ROTEM®) might be useful to detect intraoperative coagulation disorders early in major paediatric surgery. This observational trial compares this technique to standard coagulation tests. Methods Intraoperative blood sampling was obtained in children undergoing elective major surgery. At each time point, standard coagulation tests [activated partial thromboplastin time (aPTT), prothrombin time (PT), and fibrinogen level] and ROTEM® analyses (InTEM, ExTEM, and FibTEM) were performed simultaneously by trained hospital laboratory staff. Results A total of 288 blood samples from 50 subjects were analysed. While there was a poor correlation between PT and aPTT to ExTEM clotting time (CT) and InTEM CT, respectively, a good correlation was detected between PT and aPTT to clot formation time, and a very good correlation between fibrinogen level and FibTEM assay (r=0.882, P Conclusions PT and aPTT cannot be interchangeably used with ROTEM® CT. Based on the results of ROTEM®, recommended thresholds for PT and aPTT might overestimate the need for coagulation therapy. A good correlation was found between the fibrinogen level and the FibTEM assay. In addition, ROTEM® offered faster turnaround times.

Delayed cerebral ischaemia after subarachnoid haemorrhage: looking beyond vasospasm

Abstract: Despite improvements in the clinical management of aneurysmal subarachnoid haemorrhage over the last decade, delayed cerebral ischaemia (DCI) remains the single most important cause of morbidity and mortality in those patients who survive the initial bleed. The pathological mechanisms underlying DCI are still unclear and the calcium channel blocker nimodipine remains the only therapeutic intervention proven to improve functional outcomes after SAH. The recent failure of the drug clazosentan to improve functional outcomes despite reducing vasoconstriction has moved the focus of research into DCI away from cerebral artery constriction towards a more multifactorial aetiology. Novel pathological mechanisms have been suggested, including damage to cerebral tissue in the first 72 h after aneurysm rupture ('early brain injury'), cortical spreading depression, and microthrombosis. A greater understanding of the significance of these pathophysiological mechanisms and potential genetic risk factors is required, if new approaches to the prophylaxis, diagnosis, and treatment of DCI are to be developed. Furthermore, objective and reliable biomarkers are needed for the diagnosis of DCI in poor grade SAH patients requiring sedation and to assess the efficacy of new therapeutic interventions. The purpose of this article is to appraise these recent advances in research into DCI, relate them to current clinical practice, and suggest potential novel avenues for future research.

Which goal for fluid therapy during colorectal surgery is followed by the best outcome: near-maximal stroke volume or zero fluid balance?

Abstract: Background. We aimed to investigate whether fluid therapy with a goal of near-maximal stroke volume (SV) guided by oesophageal Doppler (ED) monitoring result in a better outcome than that with a goal of maintaining bodyweight (BW) and zero fluid balance in patients undergoing colorectal surgery. Methods. In a double-blinded clinical multicentre trial, 150 patients undergoing elective colorectal surgery were randomized to receive fluid therapy after either the goal of nearmaximal SV guided by ED (Doppler, D group) or the goal of zero balance and normal BW (Zero balance, Z group). Stratification for laparoscopic and open surgery was performed. The postoperative fluid therapy was similar in the two groups. The primary endpoint was postoperative complications defined and divided into subgroups by protocol. Analysis was performed by intention-to-treat. The follow-up was 30 days. The trial had 85% power to show a difference between the groups. Results. The number of patients undergoing laparoscopic or open surgery and the patient characteristics were similar between the groups. No significant differences between the groups were found for overall, major, minor, cardiopulmonary, or tissue-healing complications (P-values: 0.79; 0.62; 0.97; 0.48; and 0.48, respectively). One patient died in each group. No significant difference was found for the length of hospital stay [median (range) Z: 5.00 (1‐61) vs D: 5.00 (2‐41); P¼0.206].

Randomized controlled trial of intraoperative goal-directed fluid therapy in aerobically fit and unfit patients having major colorectal surgery

Abstract: Background Intraoperative fluid therapy regimens using oesophageal Doppler monitoring (ODM) to optimize stroke volume (SV) (goal-directed fluid therapy, GDT) have been associated with a reduction in length of stay (LOS) and complication rates after major surgery We hypothesized that intraoperative GDT would reduce the time to surgical readiness for discharge (RfD) of patients having major elective colorectal surgery but that this effect might be less marked in aerobically fit patients Methods In this double-blinded controlled trial, 179 patients undergoing major open or laparoscopic colorectal surgery were characterized as aerobically ‘fit' (n=123) or ‘unfit' (n=56) on the basis of their performance during a cardiopulmonary exercise test Within these fitness strata, patients were randomized to receive a standard fluid regimen with or without ODM-guided intraoperative GDT Results GDT patients received an average of 1360 ml of additional intraoperative colloid The mean cardiac index and SV at skin closure were significantly higher in the GDT group than in controls Times to RfD and LOS were longer in GDT than control patients but did not reach statistical significance (median 68 vs 49 days, P=009, and median 88 vs 67 days, P=009, respectively) Fit GDT patients had an increased RfD (median 70 vs 47 days; P=001) and LOS (median 88 vs 60 days; P=001) compared with controls Conclusions Intraoperative SV optimization conferred no additional benefit over standard fluid therapy In an aerobically fit subgroup of patients, GDT was associated with detrimental effects on the primary outcome Trial registry: UK NIHR CRN 7285, ISRCTN 14680495 http://publicukcrnorguk/Search/StudyDetailaspx?StudyID=7285

Donation after circulatory death

Abstract: Summary. Donation after circulatory death (DCD) describes the retrieval of organs for the purposes of transplantation that follows death confirmed using circulatory criteria. The persisting shortfall in the availability of organs for transplantation has prompted many countries to re-introduce DCD schemes not only for kidney retrieval but increasingly for other organs with a lower tolerance for warm ischaemia such as the liver, pancreas, and lungs. DCD contrasts in many important respects to the current standard model for deceased donation, namely donation after brain death. The challenge in the practice of DCD includes how to identify patients as suitable potential DCD donors, how to support and maintain the trust of bereaved families, and how to manage the consequences of warm ischaemia in a fashion that is professionally, ethically, and legally acceptable. Many of the concerns about the practice of both controlled and uncontrolled DCD are being addressed by increasing professional consensus on the ethical and legal justification for many of the interventions necessary to facilitate DCD. In some countries, DCD after the withdrawal of active treatment accounts for a substantial proportion of deceased organ donors overall. Where this occurs, there is an increased acceptance that organ and tissue donation should be considered a routine part of end-of-life care in both intensive care unit and emergency department.

Patient blood management in Europe

Abstract: Preoperative anaemia is common in patients undergoing orthopaedic and other major surgery. Anaemia is associated with increased risks of postoperative mortality and morbidity, infectious complications, prolonged hospitalization, and a greater likelihood of allogeneic red blood cell (RBC) transfusion. Evidence of the clinical and economic disadvantages of RBC transfusion in treating perioperative anaemia has prompted recommendations for its restriction and a growing interest in approaches that rely on patients' own (rather than donor) blood. These approaches are collectively termed 'patient blood management' (PBM). PBM involves the use of multidisciplinary, multimodal, individualized strategies to minimize RBC transfusion with the ultimate goal of improving patient outcomes. PBM relies on approaches (pillars) that detect and treat perioperative anaemia and reduce surgical blood loss and perioperative coagulopathy to harness and optimize physiological tolerance of anaemia. After the recent resolution 63.12 of the World Health Assembly, the implementation of PBM is encouraged in all WHO member states. This new standard of care is now established in some centres in the USA and Austria, in Western Australia, and nationally in the Netherlands. However, there is a pressing need for European healthcare providers to integrate PBM strategies into routine care for patients undergoing orthopaedic and other types of surgery in order to reduce the use of unnecessary transfusions and improve the quality of care. After reviewing current PBM practices in Europe, this article offers recommendations supporting its wider implementation, focusing on anaemia management, the first of the three pillars of PBM.

Intraoperative fluids: how much is too much?

Abstract: There is increasing evidence that intraoperative fluid therapy decisions may influence postoperative outcomes. In the past, patients undergoing major surgery were often administered large volumes of crystalloid, based on a presumption of preoperative dehydration and nebulous intraoperative 'third space' fluid loss. However, positive perioperative fluid balance, with postoperative fluid-based weight gain, is associated with increased major morbidity. The concept of 'third space' fluid loss has been emphatically refuted, and preoperative dehydration has been almost eliminated by reduced fasting times and use of oral fluids up to 2 h before operation. A 'restrictive' intraoperative fluid regimen, avoiding hypovolaemia but limiting infusion to the minimum necessary, initially reduced major complications after complex surgery, but inconsistencies in defining restrictive vs liberal fluid regimens, the type of fluid infused, and in definitions of adverse outcomes have produced conflicting results in clinical trials. The advent of individualized goal-directed fluid therapy, facilitated by minimally invasive, flow-based cardiovascular monitoring, for example, oesophageal Doppler monitoring, has improved outcomes in colorectal surgery in particular, and this monitor has been approved by clinical guidance authorities. In the contrasting clinical context of relatively low-risk patients undergoing ambulatory surgery, high-volume crystalloid infusion (20-30 ml kg(-1)) reduces postoperative nausea and vomiting, dizziness, and pain. This review revises relevant physiology of body water distribution and capillary-tissue flow dynamics, outlines the rationale behind the fluid regimens mentioned above, and summarizes the current clinical evidence base for them, particularly the increasing use of individualized goal-directed fluid therapy facilitated by oesophageal Doppler monitoring.

Association between fibrinogen level and severity of postpartum haemorrhage: secondary analysis of a prospective trial

Abstract: Background The aim of the study was to determine whether the fibrinogen level at diagnosis of postpartum haemorrhage (PPH) is associated with the severity of bleeding. Methods This is a secondary analysis of a population-based study in 106 French maternity units identifying cases of PPH prospectively. PPH was defined by a blood loss exceeding 500 ml during the 24 h after delivery or a peripartum haemoglobin decrease of more than 20 g litre−1. This analysis includes 738 women with PPH after vaginal delivery. Fibrinogen levels were compared in patients whose PPH worsened and became severe and those whose PPH remained non-severe. Severe PPH was defined as haemorrhage by occurrence of one of the following events: peripartum haemoglobin decrease ≥40 g litre−1, transfusion of concentrated red cells, arterial embolization or emergency surgery, admission to intensive care, or death. Results The mean fibrinogen concentration at diagnosis was 4.2 g litre−1 [standard deviation (sd)=1.2 g litre−1] among the patients without worsening and 3.4 g litre−1 (sd=0.9 g litre−1) (P Conclusions The fibrinogen level at PPH diagnosis is a marker of the risk of aggravation and should serve as an alert to clinicians.

Organ transplantation: historical perspective and current practice

Abstract: Summary Over the course of the last century, organ transplantation has overcome major technical limitations to become the success it is today. The breakthroughs include developing techniques for vascular anastomoses, managing the immune response (initially by avoiding it with the use of identical twins and subsequently controlling it with chemical immunosuppressants), and devising preservation solutions that enable prolonged periods of ex vivo storage while preserving function. One challenge that has remained from the outset is to overcome the shortage of suitable donor organs. The results of organ transplantation continue to improve, both as a consequence of the above innovations and the improvements in peri- and postoperative management. This review describes some of the achievements and challenges of organ transplantation.

Management of the heartbeating brain-dead organ donor

Abstract: The main factor limiting organ donation is the availability of suitable donors and organs. Currently, most transplants follow multiple organ retrieval from heartbeating brain-dead organ donors. However, brain death is often associated with marked physiological instability, which, if not managed, can lead to deterioration in organ function before retrieval. In some cases, this prevents successful donation. There is increasing evidence that moderation of these pathophysiological changes by active management in Intensive Care maintains organ function, thereby increasing the number and functional quality of organs available for transplantation. This strategy of active donor management requires an alteration of philosophy and therapy on the part of the intensive care unit clinicians and has significant resource implications if it is to be delivered reliably and safely. Despite increasing consensus over donor management protocols, many of their components have not yet been subjected to controlled evaluation. Hence the optimal combinations of treatment goals, monitoring, and specific therapies have not yet been fully defined. More research into the component techniques is needed.

Effect of a patient blood management programme on preoperative anaemia, transfusion rate, and outcome after primary hip or knee arthroplasty: a quality improvement cycle.

Abstract: Methods. We retrospectively audited 717 primary hip or knee arthroplasties in a UK general hospital and conducted regression analyses to identify outcome predictors. We used these data to modify previously published algorithms for UK practice and audited its introduction prospectively. The retrospective audit group served as a control. Results. Preoperative haemoglobin (Hb) concentration predicted ABT (odds ratio 0.25 per 1 g dl 21 , P,0.001). It also predicted the length of stay (LOS, effect size 2 0.7 days per 1gd l 21 , P¼0.004) independently of ABT, including in non-anaemic patients. Patient blood management implementation was associated with lower ABT rates for hip (23–7%, P,0.001) and knee (7– 0%, P¼0.001) arthroplasty. LOS for total hip replacement and total knee replacement decreased from 6 (5–8) days to 5 (3–7) and 4 (3–6) days, respectively, after algorithm implementation (P,0.001). The all-cause re-admission rate within 90 days decreased from 13.5% (97/717) before to 8.2% (23/281) after algorithm implementation (P¼0.02).

Can anaesthetic and analgesic techniques affect cancer recurrence or metastasis

Abstract: Summary Cancer is a leading cause of morbidity and mortality worldwide and the ratio of incidence is increasing. Mortality usually results from recurrence or metastases. Surgical removal of the primary tumour is the mainstay of treatment, but this is associated with inadvertent dispersal of neoplastic cells into the blood and lymphatic systems. The fate of the dispersed cells depends on the balance of perioperative factors promoting tumour survival and growth (including surgery per se, many anaesthetics per se, acute postoperative pain, and opioid analgesics) together with the perioperative immune status of the patient. Available evidence from experimental cell culture and live animal data on these factors are summarized, together with clinical evidence from retrospective studies. Taken together, current data are sufficient only to generate a hypothesis that an anaesthetic technique during primary cancer surgery could affect recurrence or metastases, but a causal link can only be proved by prospective, randomized, clinical trials. Many are ongoing, but definitive results might not emerge for a further 5 yr or longer. Meanwhile, there is no hard evidence to support altering anaesthetic technique in cancer patients, pending the outcome of the ongoing clinical trials.

Tracheal intubation in the critically ill: a multi-centre national study of practice and complications

Abstract: Background Complications associated with tracheal intubation may occur in up to 40% of critically ill patients. Since practice in emergency airway management varies between intensive care units (ICUs) and countries, complication rates may also differ. We undertook a prospective, observational study of tracheal intubation performed by critical care doctors in Scotland to identify practice, complications, and training. Methods For 4 months, we collected data on any intubation performed by doctors working in critical care throughout Scotland except those in patients having elective surgery and those carried out before admission to hospital. We used a standardized data form to collect information on pre-induction physical state and organ support, the doctor carrying out the intubation, the techniques and drugs used, and complications noted. Results Data from 794 intubations were analysed. Seventy per cent occurred in ICU and 18% occurred in emergency departments. The first-time intubation success rate was 91%, no patient required more than three attempts at intubation, and one patient required surgical tracheostomy. Severe hypoxaemia (SpO2 Conclusions Tracheal intubation by critical care doctors in Scotland has a higher first-time success rate than described in previous reports of critical care intubation, and technical complications are few. Doctors carrying out intubation had undergone longer formal training in anaesthesia than described previously, and junior trainees are routinely supervised. Despite these good results, further work is necessary to reduce physiological complications and patient morbidity.

Surgical safety checklists: do they improve outcomes?

Abstract: Summary The concept of using a checklist in surgical and anaesthetic practice was energized by publication of the WHO Surgical Safety Checklist in 2008. It was believed that by routinely checking common safety issues, and by better team communication and dynamics, perioperative morbidity and mortality could be improved. The magnitude of improvement demonstrated by the WHO pilot studies was surprising. These initial results have been confirmed by further detailed work demonstrating that surgical checklists, when properly implemented, can make a substantial difference to patient safety. However, introducing surgical checklists is not as straightforward as it seems, and requires leadership, flexibility, and teamwork in a different way to that which is currently practiced. Future work should be aimed at ensuring effective implementation of the WHO Surgical Safety Checklist, which will benefit our patients on a global scale.

Haemostatic monitoring during postpartum haemorrhage and implications for management

Abstract: Postpartum haemorrhage (PPH) is a major risk factor for maternal morbidity and mortality. PPH has numerous causative factors, which makes its occurrence and severity difficult to predict. Underlying haemostatic imbalances such as consumptive and dilutional coagulopathies may develop during PPH, and can exacerbate bleeding and lead to progression to severe PPH. Monitoring coagulation status in patients with PPH may be crucial for effective haemostatic management, goal-directed therapy, and improved outcomes. However, current PPH management guidelines do not account for the altered baseline coagulation status observed in pregnant patients, and the appropriate transfusion triggers to use in PPH are unknown, due to a lack of high-quality studies specific to this area. In this review, we consider the evidence for the use of standard laboratory-based coagulation tests and point-of-care viscoelastic coagulation monitoring in PPH. Many laboratory-based tests are unsuitable for emergency use due to their long turnaround times, so have limited value for the management of PPH. Emerging evidence suggests that viscoelastic monitoring, using thrombelastography- or thromboelastometry-based tests, may be useful for rapid assessment and for guiding haemostatic therapy during PPH. However, further studies are needed to define the ranges of reference values that should be considered ‘normal’ in this setting. Improving awareness of the correct application and interpretation of viscoelastic coagulation monitoring techniques may be critical in realizing their emergency diagnostic potential.

Transfusion and risk of acute kidney injury in cardiac surgery

Abstract: Acute kidney injury (AKI) is a serious and common complication of major surgery. This narrative review focuses on the relationship between perioperative red blood cell transfusion and AKI after cardiac surgery with cardiopulmonary bypass (CPB). Numerous observational studies have shown that these two factors are independently associated with each other. Several lines of evidence suggest that the nature of this association is one of cause and effect. The pathophysiological mechanism by which transfusions might harm the kidney has not been fully elucidated, but it is known that erythrocytes undergo irreversible morphological and biochemical changes during storage. As a result, after transfusion, they can promote a pro-inflammatory state, impair tissue oxygen delivery, and exacerbate tissue oxidative stress. This in turn can cause AKI in susceptible patients undergoing cardiac surgery with CPB, such as those with pre-existing kidney dysfunction or anaemia. Interventions aimed at avoiding perioperative blood transfusion might, therefore, reduce the risk of AKI after cardiac and other types of surgery.

International practices of organ donation

Abstract: Summary Organ donation and transplant rates vary widely across the globe, but there remains an almost universal shortage of deceased donors. The unmet need for transplants has resulted in many systematic approaches to increase donor rates, but there have also been practices that have crossed the boundaries of legal and ethical acceptability. Recent years have seen intense interest from international political organizations, led by the World Health Organization, and professional bodies, led by The Transplantation Society. Their efforts have focused on the development of a series of legal and ethical frameworks, designed to encourage all countries to eradicate unacceptable practices while introducing programmes that strive to achieve national or regional self-sufficiency in meeting the need for organ transplants. These programmes should seek to reduce both the need for transplantation and also develop deceased donation to its maximum potential. Living donation remains the mainstay of transplantation in many parts of the world, and many of the controversial—and unacceptable—areas of practice are found in the exploitation of living donors. However, until lessons are learnt, and applied, from countries with highly developed deceased donor programmes, these abuses of human rights will be difficult to eradicate. A clear international framework is now in place to achieve this.

Transversus abdominis plane block for postoperative analgesia after Caesarean delivery performed under spinal anaesthesia? A systematic review and meta-analysis

Abstract: The transversus abdominis plane (TAP) block is a field block that provides postoperative analgesia for abdominal surgery. Its analgesic utility after Caesarean delivery (CD) remains controversial. This systematic review and meta-analysis examines whether TAP block can reduce i.v. morphine consumption in the first 24 h after CD. The authors retrieved randomized controlled trials comparing TAP block with placebo in CD. Postoperative i.v. morphine consumption during the first 24 h was selected as a primary outcome. Pain scores and both maternal and neonatal opioid-related side-effects were secondary outcomes. Where possible, meta-analytic techniques and random effects modelling were used to combine data. Trials were stratified based on whether or not spinal morphine was used as part of the analgesic regimen. Five trials including 312 patients were identified. TAP block reduced the mean 24 h i.v. morphine consumption by 24 mg [95% confidence interval (CI) -39.65 to -7.78] when spinal morphine was not used. TAP block also reduced visual analogue scale pain scores (10 cm line where 0 cm, no pain, and 10 cm, worst pain) by 0.8 cm (95% CI -1.53 to -0.05, P=0.01), and decreased the incidence of opioid-related side-effects. The differences in primary and secondary outcomes were not significant when spinal morphine was used. TAP block provides superior analgesia compared with placebo and can reduce the first 24 h morphine consumption in the setting of a multimodal analgesic regimen that excludes spinal morphine. TAP block can provide effective analgesia when spinal morphine is contraindicated or not used.

Outcomes and prognostic factors in patients with haematological malignancy admitted to a specialist cancer intensive care unit: a 5 yr study

Abstract: Background Long-held assumptions of poor prognoses for patients with haematological malignancies (HM) have meant that clinicians have been reluctant to admit them to the intensive care unit (ICU). We aimed to evaluate ICU, in-hospital, and 6 month mortality and to identify predictors for in-hospital mortality. Methods A cohort study in a specialist cancer ICU of adult HM patients admitted over 5 yr. Data acquired included: patient characteristics, haematological diagnosis, haematopoietic stem cell transplant (HSCT), reason for ICU admission, and APACHE II scores. Laboratory values, organ failures, and level of organ support were recorded on ICU admission. Predictors for in-hospital mortality were evaluated using uni- and multivariate analysis. Results Of 199 patients, median age was 58 yr [inter-quartile range (IQR) 46–66], 51.7% were emergency admissions, 42.2% post-HSCT, 51.9% required mechanical ventilation, median APACHE II was 21 (IQR 16–25), and median organ failure numbered 2 (IQR 1–4). ICU, in-hospital, and 6 month mortalities were 33.7%, 45.7%, and 59.3%, respectively. Univariate analysis revealed bilirubin >32 µmol litre−1, mechanical ventilation, ≥2 organ failures, renal replacement therapy, vasopressor support (all P Conclusions Mortality was lower than in previous studies. Mechanical ventilation and ≥2 organ failures were independently associated with in-hospital mortality. ‘Traditional' variables such as neutropenia, transplantation status, and APACHE II score no longer appear to be predictive.

Adverse event reporting tool to standardize the reporting and tracking of adverse events during procedural sedation: a consensus document from the World SIVA International Sedation Task Force

Abstract: Currently, there are no established definitions or terminology for sedation-related adverse events (AEs). With clear terminology and definitions, sedation events may be accurately identified and tracked, providing a benchmark for defining the occurrence of AEs, ranging from minimal to severe. This terminology could apply to sedation performed in any location and by any provider. We present a consensus document from the International Sedation Task Force (ISTF) of the World Society of Intravenous Anaesthesia (World SIVA). The ISTF is composed of adult and paediatric sedation practitioners from multiple disciplines throughout the world.

Ventilation strategies in obese patients undergoing surgery: a quantitative systematic review and meta-analysis.

Abstract: Background Pathophysiological changes due to obesity may complicate mechanical ventilation during general anaesthesia. The ideal ventilation strategy is expected to optimize gas exchange and pulmonary mechanics and to reduce the risk of respiratory complications. Methods Systematic search (databases, bibliographies, to March 2012, all languages) was performed for randomized trials testing intraoperative ventilation strategies in obese patients (BMI ≥30 kg m−2), and reporting on gas exchange, pulmonary mechanics, or pulmonary complications. Meta-analyses were performed when data from at least three studies or 100 patients could be combined. Results Thirteen studies (505 obese surgical patients) reported on a variety of ventilation strategies: pressure- or volume-controlled ventilation (PCV, VCV), various tidal volumes, and different PEEP or recruitment manoeuvres (RM), and combinations thereof. Definitions and reporting of endpoints were inconsistent. In five trials (182 patients), RM added to PEEP compared with PEEP alone improved intraoperative PaO2/F I O2 ratio [weighted mean difference (WMD), 16.2 kPa; 95% confidence interval (CI), 8.0–24.4] and increased respiratory system compliance (WMD, 14 ml cm H2O−1; 95% CI, 8–20). Arterial pressure remained unchanged. In four trials (100 patients) comparing PCV with VCV, there was no difference in PaO2/F I O2 ratio, tidal volume, or arterial pressure. Comparison of further ventilation strategies or combination of other outcomes was not feasible. Data on postoperative complications were seldom reported. Conclusions The ideal intraoperative ventilation strategy in obese patients remains obscure. There is some evidence that RM added to PEEP compared with PEEP alone improves intraoperative oxygenation and compliance without adverse effects. There is no evidence of any difference between PCV and VCV.

Risks for impaired cerebral autoregulation during cardiopulmonary bypass and postoperative stroke

Abstract: Background Impaired cerebral autoregulation may predispose patients to cerebral hypoperfusion during cardiopulmonary bypass (CPB). The purpose of this study was to identify risk factors for impaired autoregulation during coronary artery bypass graft, valve surgery with CPB, or both and to evaluate whether near-infrared spectroscopy (NIRS) autoregulation monitoring could be used to identify this condition. Methods Two hundred and thirty-four patients were monitored with transcranial Doppler and NIRS. A continuous, moving Pearson's correlation coefficient was calculated between mean arterial pressure (MAP) and cerebral blood flow (CBF) velocity, and between MAP and NIRS data, to generate the mean velocity index (Mx) and cerebral oximetry index (COx), respectively. Functional autoregulation is indicated by an Mx and COx that approach zero (no correlation between CBF and MAP); impaired autoregulation is indicated by an Mx and COx approaching 1. Impaired autoregulation was defined as an Mx ≥0.40 at all MAPs during CPB. Results Twenty per cent of patients demonstrated impaired autoregulation during CPB. Based on multivariate logistic regression analysis, time-averaged COx during CPB, male gender, PaCO2, CBF velocity, and preoperative aspirin use were independently associated with impaired CBF autoregulation. Perioperative stroke occurred in six of 47 (12.8%) patients with impaired autoregulation compared with five of 187 (2.7%) patients with preserved autoregulation (P=0.011). Conclusions Impaired CBF autoregulation occurs in 20% of patients during CPB. Patients with impaired autoregulation are more likely than those with functional autoregulation to have perioperative stroke. Non-invasive monitoring autoregulation may provide an accurate means to predict impaired autoregulation. Clinical trials registration. www.clinicaltrials.gov (NCT00769691).

Cognitive errors detected in anaesthesiology: a literature review and pilot study

Abstract: Background Cognitive errors are thought-process errors, or thinking mistakes, which lead to incorrect diagnoses, treatments, or both. This psychology of decision-making has received little formal attention in anaesthesiology literature, although it is widely appreciated in other safety cultures, such as aviation, and other medical specialities. We sought to identify which types of cognitive errors are most important in anaesthesiology. Methods This study consisted of two parts. First, we created a cognitive error catalogue specific to anaesthesiology practice using a literature review, modified Delphi method with experts, and a survey of academic faculty. In the second part, we observed for those cognitive errors during resident physician management of simulated anaesthesiology emergencies. Results Of >30 described cognitive errors, the modified Delphi method yielded 14 key items experts felt were most important and prevalent in anaesthesiology practice (Table 1). Faculty survey responses narrowed this to a ‘top 10' catalogue consisting of anchoring, availability bias, premature closure, feedback bias, framing effect, confirmation bias, omission bias, commission bias, overconfidence, and sunk costs (Table 2). Nine types of cognitive errors were selected for observation during simulated emergency management. Seven of those nine types of cognitive errors occurred in >50% of observed emergencies (Table 3). Conclusions Cognitive errors are thought to contribute significantly to medical mishaps. We identified cognitive errors specific to anaesthesiology practice. Understanding the key types of cognitive errors specific to anaesthesiology is the first step towards training in metacognition and de-biasing strategies, which may improve patient safety.