Functional capacity is an important component of risk assessment for major surgery. Doctors' clinical subjective assessment of patients' functional capacity has uncertain accuracy. We did a study to compare preoperative subjective assessment with alternative markers of fitness (cardiopulmonary exercise testing [CPET], scores on the Duke Activity Status Index [DASI] questionnaire, and serum N-terminal pro-B-type natriuretic peptide [NT pro-BNP] concentrations) for predicting death or complications after major elective non-cardiac surgery. We did a multicentre, international, prospective cohort study at 25 hospitals: five in Canada, seven in the UK, ten in Australia, and three in New Zealand. We recruited adults aged at least 40 years who were scheduled for major non-cardiac surgery and deemed to have one or more risk factors for cardiac complications (eg, a history of heart failure, stroke, or diabetes) or coronary artery disease. Functional capacity was subjectively assessed in units of metabolic equivalents of tasks by the responsible anaesthesiologists in the preoperative assessment clinic, graded as poor (10). All participants also completed the DASI questionnaire, underwent CPET to measure peak oxygen consumption, and had blood tests for measurement of NT pro-BNP concentrations. After surgery, patients had daily electrocardiograms and blood tests to measure troponin and creatinine concentrations until the third postoperative day or hospital discharge. The primary outcome was death or myocardial infarction within 30 days after surgery, assessed in all participants who underwent both CPET and surgery. Prognostic accuracy was assessed using logistic regression, receiver-operating-characteristic curves, and net risk reclassification. Between March 1, 2013, and March 25, 2016, we included 1401 patients in the study. 28 (2%) of 1401 patients died or had a myocardial infarction within 30 days of surgery. Subjective assessment had 19·2% sensitivity (95% CI 14·2-25) and 94·7% specificity (93·2-95·9) for identifying the inability to attain four metabolic equivalents during CPET. Only DASI scores were associated with predicting the primary outcome (adjusted odds ratio 0·96, 95% CI 0·83-0·99; p=0·03). Subjectively assessed functional capacity should not be used for preoperative risk evaluation. Clinicians could instead consider a measure such as DASI for cardiac risk assessment. Canadian Institutes of Health Research, Heart and Stroke Foundation of Canada, Ontario Ministry of Health and Long-Term Care, Ontario Ministry of Research, Innovation and Science, UK National Institute of Academic Anaesthesia, UK Clinical Research Collaboration, Australian and New Zealand College of Anaesthetists, and Monash University.

Blood loss and subsequent transfusions are associated with major morbidity and mortality. The use of antifibrinolytics can reduce blood loss in cardiac surgery, trauma, orthopedic surgery, liver surgery and solid organ transplantation, obstetrics and gynecology, neurosurgery and non-surgical diseases. The evidence of their efficacy has been mounting for years. Tranexamic acid (TXA), a synthetic lysine-analogue antifibrinolytic, was first patented in 1957 and its use has been increasing in contrast to aprotinin, a serine protease inhibitor antifibrinolytic. This review aims to help acute care physicians navigate through the clinical evidence available for TXA therapy, develop appropriate dose regimens whilst minimizing harm, as well as understand its broadening scope of applications. Many questions remain unanswered regarding other clinical effects of TXA such as anti-inflammatory response to cardiopulmonary bypass, the risk of thromboembolic events, adverse neurological effects such as seizures, and its morbidity and mortality, all of which necessitate further clinical trials on its usage and safety in various clinical settings. Blood loss and subsequent transfusions are associated with major morbidity and mortality. The use of antifibrinolytics can reduce blood loss in cardiac surgery, trauma, orthopedic surgery, liver surgery and solid organ transplantation, obstetrics and gynecology, neurosurgery and non-surgical diseases. The evidence of their efficacy has been mounting for years. Tranexamic acid (TXA), a synthetic lysine-analogue antifibrinolytic, was first patented in 1957 and its use has been increasing in contrast to aprotinin, a serine protease inhibitor antifibrinolytic. This review aims to help acute care physicians navigate through the clinical evidence available for TXA therapy, develop appropriate dose regimens whilst minimizing harm, as well as understand its broadening scope of applications. Many questions remain unanswered regarding other clinical effects of TXA such as anti-inflammatory response to cardiopulmonary bypass, the risk of thromboembolic events, adverse neurological effects such as seizures, and its morbidity and mortality, all of which necessitate further clinical trials on its usage and safety in various clinical settings.

Summary: Because of a lack of contemporary data regarding seizures after cardiac surgery, we undertook a retrospective analysis of prospectively collected data from 11 529 patients in whom cardiopulmonary bypass was used from January 2004 to December 2010. A convulsive seizure was defined as a transient episode of disturbed brain function characterised by abnormal involuntary motor movements. Multivariate regression analysis was performed to identify independent predictors of postoperative seizures. A total of 100 (0.9%) patients developed postoperative convulsive seizures. Generalised and focal seizures were identified in 68 and 32 patients, respectively. The median (IQR [range]) time after surgery when the seizure occurred was 7 (6–12 [1–216]) h and 8 (6–11 [4–18]) h, respectively. Epileptiform findings on electroencephalography were seen in 19 patients. Independent predictors of postoperative seizures included age, female sex, redo cardiac surgery, calcification of ascending aorta, congestive heart failure, deep hypothermic circulatory arrest, duration of aortic cross‐clamp and tranexamic acid. When tested in a multivariate regression analysis, tranexamic acid was a strong independent predictor of seizures ( OR 14.3, 95% CI 5.5–36.7; p < 0.001). Patients with convulsive seizures had 2.5 times higher in‐hospital mortality rates and twice the length of hospital stay compared with patients without convulsive seizures. Mean ( IQR [range]) length of stay in the intensive care unit was 115 (49–228 [32–481]) h in patients with convulsive seizures compared with 26 (22–69 [14–1080]) h in patients without seizures (p < 0.001). Convulsive seizures are a serious postoperative complication after cardiac surgery. As tranexamic acid is the only modifiable factor, its administration, particularly in doses exceeding 80 mg.kg ⁻¹ , should be weighed against the risk of postoperative seizures.

Volatile anesthetic agent use in the intensive care unit, aided by technological advances, has become more accessible to critical care physicians. With increasing concern over adverse patient consequences associated with our current sedation practice, there is growing interest to find non–benzodiazepine-based alternative sedatives. Research has demonstrated that volatile-based sedation may provide superior awakening and extubation times in comparison with current intravenous sedation agents (propofol and benzodiazepines). Volatile agents may possess important end-organ protective properties mediated via cytoprotective and antiinflammatory mechanisms. However, like all sedatives, volatile agents are capable of deeply sedating patients, which can have respiratory depressant effects and reduce patient mobility. This review seeks to critically appraise current volatile use in critical care medicine including current research, technical consideration of their use, contraindications, areas of controversy, and proposed future research topics.

Summary: This systematic review and meta‐analysis appraises the utility of point‐of‐care platelet function tests for predicting blood loss and transfusion requirements in cardiac surgical patients, and analyses whether their use within a transfusion management algorithm is associated with improved patient outcomes. We included 30 observational studies incorporating 3044 patients in the qualitative assessment, and nine randomised controlled trials including 1057 patients in the meta‐analysis. Platelet function tests demonstrated significant variability in their ability to predict blood loss and transfusion requirements. Their use within a blood transfusion algorithm demonstrated a reduction in blood loss at longest follow‐up (mean difference −102.9 ml (95% CI −149.9 to −56.1 ml), p < 0.001), and transfusion of packed red cells ( RR 0.86 (95% CI 0.78−0.94), p = 0.001) and fresh frozen plasma ( RR 0.42 (95% CI 0.30−0.59), p < 0.001). Viscoelastic methods used in combination with other platelet function tests achieved greater reduction in blood loss (mean difference −111.8 ml (95% CI −174.9 to −49.1 ml), p = 0.0005) compared with their use alone (mean difference −90.6 ml (95% CI 166.1−15.0 ml), p = 0.02). We conclude that incorporation of point‐of‐care platelet function tests into transfusion management algorithms is associated with a reduction in blood loss and transfusion requirements in cardiac surgery patients.

Administrative electronic databases are highly specific for postoperative complications, but they lack sensitivity. The objective of this study was to determine the incidence of delirium after cardiac surgery using a targeted prospectively collected dataset and to compare the findings with the incidence of delirium in the same cohort of patients identified in a hospital administrative database. Following Research Ethics Board approval, we compared delirium rates in a prospectively collected data research database with delirium rates in the same cohort of patients in an administrative hospital database where delirium was identified from codes entered by coding and abstracting staff. Every 12 hr postoperatively, delirium was assessed with a Confusion Assessment Method in the Intensive Care Unit. The administrative database contained the International Classification of Diseases version 10 (ICD-10) codes for patient diagnoses. The ICD-10 codes were extracted from the administrative database for each patient in the research database and were checked for the presence of the ICD-10 code for delirium. Data from a cohort of 1,528 patients were analyzed. Postoperative delirium was identified in 182 (11.9%) patients (95% confidence interval [CI], 10.3-13.5%) in the research dataset and 46 (3%) patients (95% CI, 2.2-3.8%) in the administrative dataset (P < 0.001). Thirteen (0.85%) patients who were coded for delirium in the administrative database were not identified in the research dataset. The median onset of postoperative delirium in these patients was significantly delayed (4 [3-9] days) compared with patients identified by both datasets (2 [1-9] days) and compared with patients from the research database only (1 [1-14] days) (P = 0.007). Postoperative delirium rates after cardiac surgery are underestimated by the hospital administrative database. Les bases de données électroniques administratives sont très spécifiques quant aux complications postopératoires, mais elles manquent de sensibilité. L’objectif de cette étude était de déterminer l’incidence de delirium après chirurgie cardiaque à l’aide d’un ensemble de données ciblées et colligées de façon prospective ainsi que de comparer ces résultats avec l’incidence de delirium dans la même cohorte de patients identifiés dans une base de données administrative hospitalière. Après avoir obtenu le consentement du Comité d’éthique de la recherche, nous avons comparé les taux de delirium dans une base de données de recherche colligée de façon prospective aux taux de delirium de la même cohorte de patients dans la base de données administrative de l’hôpital, dans laquelle le delirium a été identifié à partir de codes saisis par le personnel de saisie et d’analyse des données. Le delirium a été évalué à l’aide d’une méthode d’évaluation de la confusion dans l’unité des soins intensifs toutes les 12 heures en postopératoire. La base de données administrative comprenait les codes de la Classification internationale des maladies, 10^e révision (CIM-10) pour les diagnostics des patients. Les codes de la CIM-10 ont été récupérés de la base de données administrative pour chaque patient de la base de données de recherche et nous avons vérifié si le code de la CIM-10 pour le delirium était inclus. Les données d’une cohorte de 1528 patients ont été analysées. Le delirium postopératoire a été identifié chez 182 (11,9 %) patients (intervalle de confiance [IC] 95 %, 10,3-13,5 %) dans l’ensemble de données de recherche et 46 (3 %) patients (IC 95 %, 2,2-3,8 %) dans l’ensemble de données administratives (P < 0,001). Treize (0,85 %) patients codés pour le delirium dans la base de données administrative n’ont pas été identifiés dans l’ensemble de données de recherche. Chez ces patients, le delirium postopératoire apparaissait significativement plus tard (médiane : 4 [3-9] jours) que chez les patients identifiés dans les deux ensembles de données (2 [1-9] jours) et que chez les patients inclus seulement dans la base de données de recherche (1 [1-14] jours) (P = 0,007). La base de données administrative de l’hôpital sous-estime l’incidence de delirium postopératoire après une chirurgie cardiaque.