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.

Poor agreement in significant findings between meta-analyses and subsequent large randomized trials in perioperative medicine.

BACKGROUND: The reliability of meta-analysis (MA) in predicting the findings of subsequent large randomized controlled trials (RCTs) has not been assessed in perioperative medicine and anaesthesia. METHODS: Using Medline and PubMed, large RCTs (n≥1000) published since 2000 in the anaesthesia and perioperative medicine/critical care literature were identified. All previous MAs of RCTs investigating the same intervention and population were sourced. For all reported major morbid endpoints common to each, results (significant/non-significant P<0.05) were compared. RESULTS: 18 large RCTs and 44 prior MAs investigating the effects of 16 interventions were identified. Where endpoint results in the large RCTs were each compared with the single largest recent preceding MA, 35 of a total of 57 outcomes were predicted correctly by the MAs (61.4%). The odds ratio for a significant result from MA compared with the subsequent large RCT was 3.6, P=0.033 Bonferroni corrected. The positive predictive value of MAs was 22.7%; the negative predictive value was 85.7%, Kappa was 0.094 indicating slight agreement. The estimated power for each endpoint for large RCTs and MAs were similar, but the median study size for large RCTs was larger than that of the MAs, n=4,482 vs 1,389, P<0.0001. CONCLUSIONS: There was a strong tendency towards positive findings in MA not substantiated by subsequent large RCTs, which was not attributable to differences in study power. This finding suggests caution in clinical decision-making in anaesthesia and perioperative medicine based on findings of meta-analysis.

Postoperative pain after laparoscopic cholecystectomy is not reduced by intraoperative analgesia guided by analgesia nociception index (ANI®) monitoring: a randomized clinical trial.

BACKGROUND: Laparoscopic cholecystectomy frequently results in significant immediate postoperative pain. A new pain monitor, analgesic nociception index (ANI®), based on heart rate variability, has recently been approved for intraoperative nociception monitoring. We designed a single-blind, parallel-group, randomized control trial to test the hypothesis that protocol-driven intraoperative analgesia guided by ANI during laparoscopic cholecystectomy would improve titration of intraoperative analgesics leading to decreased postoperative pain. METHODS: One hundred and twenty consecutive adult participants presenting for elective laparoscopic cholecystectomy were recruited. Participants were randomly allocated by sealed envelope to receive intraoperative morphine either guided by ANI via a protocol (intervention group) or guided by the anaesthetist with ANI concealed (control group). All participants received paracetamol, parecoxib, fentanyl at induction, and local anaesthetic to port sites. The primary endpoint was the presence of moderate/severe pain (visual analogue scale ≥50 mm) at any of the four time points in the first postoperative hour. Secondary endpoints included postoperative rescue morphine. RESULTS: Sixty participants were randomized to each group, and all but one drop-out from the intervention group were analysed. The usage of ANI guidance did not result in a decrease in the rate of moderate/severe pain (50.8% vs 45.0%: difference of -5.8%, 95% confidence interval, -23.7% to 12.1%, P=0.58), or the use of postoperative rescue analgesia. CONCLUSIONS: This randomized control trial of intraoperative ANI-guided morphine administration in elective laparoscopic cholecystectomy failed to show any advantage over the current standard of care, and demonstrated a high level of postoperative pain, despite the use of multimodal analgesia. CLINICAL TRIAL REGISTRATION: ANZCTR Reference ACTRN12612000953831 (URL: http://www.anzctr.org.au/trial_view.aspx?ID=362949).