Development and internal validation of a multivariable risk prediction model for severe rebound pain after foot and ankle surgery involving single-shot popliteal sciatic nerve block.

BACKGROUND: Rebound pain occurs after up to 50% of ambulatory surgeries involving regional anaesthesia. To assist with risk stratification, we developed a model to predict severe rebound pain after foot and ankle surgery involving single-shot popliteal sciatic nerve block. METHODS: After ethics approval, we performed a single-centre retrospective cohort study. Patients undergoing lower limb surgery with popliteal sciatic nerve block from January 2016 to November 2019 were included. Exclusion criteria were uncontrolled pain in the PACU, use of a perineural catheter, or loss to follow-up. We developed and internally validated a multivariable logistic regression model for severe rebound pain, defined as transition from well-controlled pain in the PACU (numerical rating scale [NRS] 3 or less) to severe pain (NRS ≥7) within 48 h. A priori predictors were age, sex, surgery type, planned admission, local anaesthetic type, dexamethasone use, and intraoperative anaesthesia type. Model performance was evaluated using area under the receiver operating characteristic curve (AUROC), Nagelkerke's R2, scaled Brier score, and calibration slope. RESULTS: The cohort included 1365 patients (mean [standard deviation] age: 50 [16] yr). The primary outcome was abstracted in 1311 (96%) patients, with severe rebound pain in 652 (50%). Internal validation revealed poor model performance, with AUROC 0.632 (95% confidence interval [CI]: 0.602-0.661; bootstrap optimisation 0.021), Nagelkerke's R2 0.063, and scaled Brier score 0.047. Calibration slope was 0.832 (95% CI: 0.623-1.041). CONCLUSIONS: We show that a multivariable risk prediction model developed using routinely collected clinical data had poor predictive performance for severe rebound pain after foot and ankle surgery. Prospective studies involving other patient-related predictors are needed. CLINICAL TRIAL REGISTRATION: NCT05018104.

Case series: anesthesia for retrograde percutaneous aortic valve replacement--experience with the first 40 patients.

PURPOSE: To describe both the evolution and the main associated complications in the anesthetic management of the initial 40 patients at our centre who underwent percutaneous retrograde aortic valve replacement, a novel technique utilizing a catheter-guided femoral artery approach. CLINICAL FEATURES: With institutional Research Ethics Board approval, we retrospectively reviewed the medical records of the first 40 patients who underwent percutaneous retrograde aortic valve replacement between January 2005 and March 2006. Information obtained included patient characteristics, anesthetic management, details of the procedure, and complications. All procedures were scheduled to be performed in the cardiac catheterization laboratory. The first four patients received monitored anesthesia care, and the subsequent 36 underwent general anesthesia. There were no anesthesia-related adverse events. The prosthetic valve was placed successfully in 33/40 patients (83%). Median anesthetic time was 3.5 hr (range, 1.25-7.25 hr). Thirty-two/40 patients required vasopressor support. The most common, serious procedural complications were myocardial ischemia and arrhythmia following rapid ventricular pacing, hemorrhage from vascular injury secondary to the placement and removal of the large-bore sheath in the ilio-femoral artery, aortic rupture, and prosthetic valve maldeployment; 30-day mortality was 13% (n = 5/40). CONCLUSIONS: Percutaneous retrograde aortic valve replacement is a novel procedure that presents the anesthesiologist with unique challenges. Careful preoperative assessment, intraoperative monitoring appropriate for a major vascular procedure, and meticulous management of hemodynamics are imperative for a successful outcome. Serious complications, including major hemorrhage from vascular injury as well as arrhythmia and myocardial ischemia following rapid ventricular pacing, must be anticipated and managed in an expeditious fashion.