Statistically significant differences versus convincing evidence of real treatment effects: an analysis of the false positive risk for single-centre trials in anaesthesia.

Background: The American Statistical Association has highlighted problems with null hypothesis significance testing and outlined alternative approaches that may 'supplement or even replace P-values'. One alternative is to report the false positive risk (FPR), which quantifies the chance the null hypothesis is true when the result is statistically significant.

Methods: We reviewed single-centre, randomised trials in 10 anaesthesia journals over 6 yr where differences in a primary binary outcome were statistically significant.

Interpreting frequentist hypothesis tests: insights from Bayesian inference.

Randomized controlled trials are one of the best ways of quantifying the effectiveness of medical interventions. Therefore, when the authors of a randomized superiority trial report that differences in the primary outcome between the intervention group and the control group are "significant" (i.e.

Dead-Space Ventilation Indices and Mortality in Acute Respiratory Distress Syndrome: A Systematic Review and Meta-Analysis.

Objectives: Acute respiratory distress syndrome (ARDS) is associated with high ventilation-perfusion heterogeneity and dead-space ventilation. However, whether the degree of dead-space ventilation is associated with outcomes is uncertain. In this systematic review and meta-analysis, we evaluated the ability of dead-space ventilation measures to predict mortality in patients with ARDS.

Using the Delphi process to determine the minimum clinically important effect size for the Balanced-2 randomised controlled trial.

Background: The sample size calculation is an important step in designing randomised controlled trials. For a trial comparing a control and an intervention group, where the outcome is binary, the sample size calculation requires choosing values for the anticipated event rates in both the control and intervention groups (the effect size), and the error rates. The Difference ELicitation in TriAls guidance recommends that the effect size should be both realistic, and clinically important to stakeholder groups.

Anatomic, stage-based repair of secondary mitral valve disease.

Objective: Intervention for repair of secondary mitral valve disease is frequently associated with recurrent regurgitation. We sought to determine if there was sufficient evidence to support inclusion of anatomic indices of leaflet dysfunction in the management of secondary mitral valve disease.

Methods: We performed a systematic review and meta-analysis of published reports comparing anatomic indices of leaflet dysfunction with the complexity of valve repair and the outcome from intervention.

Fooled by Significance Testing: An Analysis of the LOVIT Vitamin C Trial.

In this article, I discuss the potential pitfalls of interpreting values, confidence intervals, and declarations of statistical significance. To illustrate the issues, I discuss the LOVIT trial, which compared high-dose vitamin C with placebo in mechanically ventilated patients with sepsis. The primary outcome - the proportion of patients who died or had persisting organ dysfunction at day 28 - was significantly higher in patients who received vitamin C ( = .

False-positive and false-negative risks for individual multicentre trials in critical care.

Background: In medical research, null hypothesis significance testing (NHST) is the dominant framework for statistical inference. NHST involves calculating -values and confidence intervals to quantify the evidence against the null hypothesis of no effect. However, -values and confidence intervals cannot tell us the probability that the hypothesis is true.

Traumatic Injury to Both Atrioventricular Valves.

• BCI encompasses a spectrum of cardiac injuries. • BCI should be considered in all patients with major thoracoabdominal trauma. • TEE is an excellent imaging method for evaluating BCI, including atrioventricular valve injury.

Venovenous extracorporeal membrane oxygenation for treating very severe pneumonia in Aotearoa New Zealand: a 16-year experience.

Aim: We sought to describe the aetiology, demographics and outcomes of patients with pneumonia undergoing venovenous extracorporeal membrane oxygenation (VV-ECMO) in Aotearoa New Zealand.

Methods: Retrospective observational study.

Results: Between January 2004 and August 2020, 133 patients underwent VV-ECMO for pneumonia.

A Bayesian analysis of mortality outcomes in multicentre clinical trials in critical care.

Background: Multicentre RCTs are widely used by critical care researchers to answer important clinical questions. However, few trials evaluating mortality outcomes report statistically significant results. We hypothesised that the low proportion of trials reporting statistically significant differences for mortality outcomes is plausibly explained by lower-than-expected effect sizes combined with a low proportion of participants who could realistically benefit from studied interventions.

Hyperlactatemia and Cardiac Surgery.

The normal blood lactate level is 0-2 mmol/L, and a value above 3-5 mmol/L is variably used to define hyperlactatemia. In cardiac surgical patients, hyperlactatemia can arise from both hypoxic and non-hypoxic mechanisms. The major non-hypoxic mechanism is likely stress-induced accelerated aerobic metabolism, in which elevated lactate results from a mass effect on the lactate/pyruvate equilibrium.

Successful rescue of an adult with refractory anaphylactic shock and abdominal compartment syndrome with venoarterial extracorporeal membrane oxygenation and bedside laparotomy.

The incidence of life-threatening anaphylactic reactions related to anesthesia is approximately 1 in 6000 anesthetics administered, and is associated with mortality as high as 5%. In such cases the use of extracorporeal membrane oxygenation (ECMO) in the setting of refractory shock following anaphylaxis may be life saving. Abdominal compartment syndrome (ACS) itself and in this case complicating ECMO support, is a potentially devastating complication of high-volume resuscitation.

Intraoperative transesophageal echocardiography for surgical repair of mitral regurgitation.

Surgical repair of the mitral valve is being increasingly performed to treat severe mitral regurgitation. Transesophageal echocardiography is an essential tool for assessing valvular function and guiding surgical decision making during the perioperative period. A careful and systematic transesophageal echocardiographic examination is necessary to ensure that appropriate information is obtained and that the correct diagnoses are obtained before and after repair.

Extracorporeal membrane oxygenation clinical dilemmas.

Three scenarios are presented, based on real patients, illustrating various clinical dilemmas involving critical illness and extracorporeal membrane oxygenation (ECMO). The scenarios are outlined in the form of questions and answers. In most cases there is no single correct answer to the dilemmas presented.

Novel biomarkers for cardiac surgery-associated acute kidney injury: a skeptical assessment of their role.

Cardiac surgery-associated acute kidney injury (AKI) is common and is associated with a high mortality rate. Traditional biomarkers of AKI (creatinine and urea) increase slowly in response to renal injury, are insensitive to mild degrees of AKI, and are influenced by nonrenal factors. There is considerable interest in novel biomarkers of AKI such as neutrophil gelatinase-associated lipocalin that increase rapidly after renal injury, detect mild degrees of AKI, and are less subject to nonrenal factors.

Postoperative care and complications after ventricular assist device implantation.

In this article, the routine postoperative care and complications of patients with ventricular assist devices are reviewed. Routine postoperative care encompasses patients who have undergone emergency ventricular assist device (VAD) implantation for acute cardiogenic shock, as a bridge to decision making, and semi-elective patients who have undergone VAD implantation for end-stage heart failure, either as destination therapy or as a bridge to heart transplantation. Early postoperative management should focus on haemodynamic optimisation, including fluid and inotrope therapy, VAD settings and support of right ventricular function.

Timely bolus insulin for glucose control during cardiopulmonary bypass.

Hyperglycemia during cardiopulmonary bypass (CPB) with glucose containing cardioplegia is common; normoglycemia is difficult to maintain and failure to do so may result in worse outcomes. The purpose of this quality improvement initiative was to show that a simple timely insulin bolus is more effective for glucose control during CPB with glucose containing cardioplegia than conventional (not standardized) glucose management in historical case-matched controls. A single bolus of insulin (.