Integration of the Duke Activity Status Index into preoperative risk evaluation: a multicentre prospective cohort study.

BACKGROUND: The Duke Activity Status Index (DASI) questionnaire might help incorporate self-reported functional capacity into preoperative risk assessment. Nonetheless, prognostically important thresholds in DASI scores remain unclear. We conducted a nested cohort analysis of the Measurement of Exercise Tolerance before Surgery (METS) study to characterise the association of preoperative DASI scores with postoperative death or complications. METHODS: The analysis included 1546 participants (≥40 yr of age) at an elevated cardiac risk who had inpatient noncardiac surgery. The primary outcome was 30-day death or myocardial injury. The secondary outcomes were 30-day death or myocardial infarction, in-hospital moderate-to-severe complications, and 1 yr death or new disability. Multivariable logistic regression modelling was used to characterise the adjusted association of preoperative DASI scores with outcomes. RESULTS: The DASI score had non-linear associations with outcomes. Self-reported functional capacity better than a DASI score of 34 was associated with reduced odds of 30-day death or myocardial injury (odds ratio: 0.97 per 1 point increase above 34; 95% confidence interval [CI]: 0.96-0.99) and 1 yr death or new disability (odds ratio: 0.96 per 1 point increase above 34; 95% CI: 0.92-0.99). Self-reported functional capacity worse than a DASI score of 34 was associated with increased odds of 30-day death or myocardial infarction (odds ratio: 1.05 per 1 point decrease below 34; 95% CI: 1.00-1.09), and moderate-to-severe complications (odds ratio: 1.03 per 1 point decrease below 34; 95% CI: 1.01-1.05). CONCLUSIONS: A DASI score of 34 represents a threshold for identifying patients at risk for myocardial injury, myocardial infarction, moderate-to-severe complications, and new disability.

Intravenous tranexamic acid and lower limb arthroplasty-a randomised controlled feasibility study.

Tranexamic acid (TA) is widely reported to reduce bleeding and the risk of blood transfusion in patients undergoing lower limb arthroplasty. No study in this setting has had adequate power to examine for the effect of TA on either uncommon, but clinically important, adverse events or patient-centric endpoints. A large randomised controlled trial (RCT) is required to address these questions. As a preliminary feasibility study, we conducted an investigator-initiated, prospective, randomised, double blind placebo-controlled trial in 140 patients, aged 45 years or older, undergoing elective primary or revision hip or knee joint replacement. Subjects were randomised to receive intravenous (IV) TA or a placebo. The primary endpoints were the proportion of patients receiving allogenic blood transfusion and the feasibility of extending our trial methodology to a large trial of TA in this population. Secondary endpoints included a range of adverse clinical and surgical events as well as several patient-centric questionnaires. Red blood cell transfusion occurred in 15% of all patients prior to discharge from hospital. Transfusion rates were significantly different between the TA and placebo groups (8.5% versus 21.7%, P=0.03). Three out of four feasibility endpoints were met, with recruitment being slower than expected. No significant differences were seen between groups in the secondary endpoints. Despite a lower rate of transfusion than that widely reported, IV TA reduced transfusion in patients undergoing lower limb arthroplasty. Our trial methodology would be feasible in the setting of a large multicentre study to investigate whether TA is safe and reduces bleeding in lower limb arthroplasty.

Predicting patients at risk of early postoperative adverse events.

Adverse events after surgery are common. Identification of markers of at-risk patients may facilitate efficient and effective perioperative resource allocation. This pilot study aimed to identify simple preoperative factors associated with postoperative adverse events. In 1291 surgical patients, the relationship between patient and surgical factors and adverse events in the post-anaesthesia care unit was examined using binomial logistic regression analysis. Adverse events in the postoperative care unit were common, including desaturation (13.6%), hypotension (5.8%) and apnoea (5.5%), with 19.9% of cases requiring attendance by an anaesthetist to manage unexpected complications. Average length of stay in the post-anaesthesia care unit was 120 minutes and prolonged stay for medical reasons was common. A number of patient and surgical factors, including surgical complexity, preoperative arrhythmia, previous anaesthetic issues and heart failure were strongly associated with these adverse events. Areas under receiver operating characteristic curves ranged from 0.63 to 0.80. Patients with adverse events in the post-anaesthesia care unit appeared to have a higher risk of intervention in postoperative wards from a medical emergency or intensive care unit team. Our preliminary findings suggest that preoperative identification of key factors may have utility in determining risk of early postoperative problems and hence, aid perioperative planning.