Daily Anesthesiology Research Analysis

BACKGROUND: Major noncardiac surgery is associated with high rates of postoperative myocardial injury and other complications. Remote ischemic preconditioning (RIPC) was reported to decrease these complication rates. However, such supportive evidence lacks robustness. METHODS: In a multinational, double-blind trial, we randomly assigned adult high-risk patients undergoing noncardiac surgical procedures to receive RIPC or sham RIPC after the induction of general anesthesia and before surgery. RIPC involved three 5-minute ischemic cycles, each followed by 5 minutes of reperfusion, using a blood pressure cuff inflated to 200 mm Hg. The primary end point was the rate of myocardial injury, defined by an increase in postoperative troponin levels above the highest 99th percentile of reference values. Secondary outcomes included myocardial infarction, stroke, acute kidney injury, need for intensive care unit, length of hospital stay, and 30-day all-cause mortality. RESULTS: We recruited 1213 patients in 25 hospitals and 8 countries. We randomly assigned 599 patients to RIPC and 614 to sham RIPC. The most frequent surgical procedures were abdominal or intrathoracic surgeries (406 patients [33.6%]). RIPC was applied to the upper limb in 1014 patients (84.8%) and to the lower limb in 182 patients (15.2%). Postoperative myocardial injury occurred in 215 of 566 patients (38.0%) in the RIPC group and in 223 of 596 patients (37.4%) in the sham RIPC group (relative risk, 1.02 [95% CI, 0.88-1.18; CONCLUSIONS: Among adult patients undergoing noncardiac surgery, RIPC did not reduce myocardial injury or other postoperative complications. REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifier: NCT02427867.

IMPORTANCE: Accurate and timely confirmation of death by neurologic criteria (DNC) is essential for clinical decision-making and organ-donation processes, yet currently available ancillary tests have suboptimal diagnostic performance or limited validation. OBJECTIVES: To determine the diagnostic accuracy, interrater reliability, and safety of brain computed tomography (CT) perfusion and CT angiography as ancillary investigations for DNC. DESIGN, SETTING, AND PARTICIPANTS: Between April 25, 2017, and March 10, 2021, a prospective, multicenter, blinded diagnostic accuracy cohort study was conducted in 15 adult intensive care units across Canada. Consecutive, critically ill adults (aged ≥18 years) with a Glasgow Coma Scale score of 3 and no confounding factors who were at high risk of DNC were included. Data collection and analysis were performed from April 2021 to July 2024. EXPOSURE: Contrast-enhanced brain CT perfusion with CT angiography reconstructions performed within 2 hours of a blinded, standardized clinical DNC examination. MAIN OUTCOMES AND MEASURES: The primary outcomes were the sensitivity and specificity of qualitative and quantitative brainstem CT perfusion for DNC determination, assessed by 2 independent neuroradiologists blinded to clinical findings; the prespecified validation threshold was greater than 98%. Secondary outcomes were the diagnostic accuracy of whole-brain CT perfusion and CT angiography, interrater reliability (Cohen κ), and adverse events associated with imaging. RESULTS: A total of 282 patients (mean [SD] age, 57.8 [15.4] years; 133 [47%] female) completed the study protocol and were included in the primary analysis; 204 (72%) of these were ultimately declared deceased by standardized clinical criteria. Qualitative brainstem CT perfusion showed a sensitivity of 98.5% (95% CI, 95.8%-99.7%) and a specificity of 74.4% (95% CI, 63.2%-83.6%); quantitative brainstem CT perfusion was not diagnostically accurate. Qualitative whole-brain CT perfusion yielded a sensitivity of 93.6% (95% CI, 89.3%-96.6%) and a specificity of 92.3% (95% CI, 84.0%-97.1%). CT angiography sensitivity ranged from 75.5% (95% CI, 69.0%-81.2%) to 87.3% (95% CI, 81.9%-91.5%), and its specificity ranged from 89.7% (95% CI, 80.8%-95.5%) to 91.0% (95% CI, 82.4%-96.3%). Interrater reliability was excellent for all ancillary tests (κ ranged from 0.81 [95% CI, 0.73-0.89] to 0.84 [95% CI, 0.78-0.91]). Fourteen patients (5%) experienced minor, self-limited adverse events; no serious adverse events occurred. CONCLUSIONS AND RELEVANCE: The observed sensitivity and specificity measures for CT perfusion and CT angiography as an ancillary test for DNC did not meet the prespecified validation threshold of greater than 98%. Clinical examination remains the cornerstone of DNC, and ancillary imaging should be interpreted cautiously within a comprehensive clinical assessment.

STUDY OBJECTIVE: This study aims to evaluate the effects of preoperative low-dose dexmedetomidine administration for one night on the incidence of postoperative delirium in elderly patients with hip fracture. DESIGN: This was a randomized, double blind, placebo-controlled clinical trial. SETTING: Lu'an Hospital of Anhui Medical University, Anhui, China. PATIENTS: Patients aged ≥65 years with hip fracture (femoral neck, intertrochanteric, or subtrochanteric fracture) and scheduled for surgical repair(total hip arthroplasty, hemiarthroplasty, internal fixation with cannulated screw or intramedullary nail) under spinal anesthesia were eligible. INTERVENTION: Patients were randomized 1:1 to receive low-dose dexmedetomidine or placebo from 8:00 pm before surgery to 8:00 am the day of surgery. MEASUREMENTS: The primary outcome was the incidence of POD between postoperative days 1 and 7 or at hospital discharge. The secondary outcome measures included preoperative sleep quality, days of delirium, visual analog scale scores in quiet and active states on postoperative days 1-3, C-reactive protein level, number of analgesic pump presses, activities of daily living score at discharge and postoperative hospital stay. Perioperative adverse events were recorded. MAIN RESULTS: Of the 248 patients randomized to the placebo (n = 124) or dexmedetomidine (n = 124) group, 233 participants (117 in the placebo group and 116 in the dexmedetomidine group) were included in the modified intention-to-treat analysis. The incidence of POD was lower in the dexmedetomidine group (10.3 %) than placebo group (22.2 %, P = 0.014). Compared to the placebo group, the dexmedetomidine group had higher preoperative Leeds Sleep Evaluation Questionnaire (LSEQ) scores (P < 0.001), lower preoperative Insomnia Severity Index (ISI) scores (P < 0.001), and lower postoperative C-reactive protein (CRP) levels (P < 0.001). No differences in other secondary outcomes and perioperative adverse events were observed between the two groups. CONCLUSION: In patients aged ≥65 years undergoing elective hip fracture surgery under spinal anesthesia, continuous overnight administration of low-dose dexmedetomidine improved sleep quality on the night before surgery and reduced the incidence of POD.