Daily Anesthesiology Research Analysis

BACKGROUND: Inhaled sedation for mechanical ventilation in patients who are critically ill is emerging as an alternative sedative strategy; however, data are scarce on its efficacy and safety in children, compared with intravenous sedation. The IsoCOMFORT trial aimed to compare the efficacy of inhaled sedation with isoflurane versus intravenous midazolam in the paediatric setting. METHODS: IsoCOMFORT was a randomised, active-control, assessor-masked, non-inferiority phase 3 trial conducted across 19 paediatric intensive care units in Spain, France, Germany, and the UK. Children aged 3-17 years who were critically ill and required invasive mechanical ventilation and sedation for an expected duration of at least 12 h were randomly assigned (2:1) via an interactive web-response system to inhaled sedation with isoflurane or to intravenous sedation with midazolam. Randomisation was done in permuted blocks (sizes 3 and 6), stratified by age group, reason for intensive care unit admission (planned or unplanned mechanical ventilation), and country, with treatment allocation masked to outcome assessors. At baseline, a target range for sedation depth was prescribed based on the COMFORT Behaviour (COMFORT-B) scale, and sedation dosing was titrated to reach the target range. Sedative treatment was planned for up to 48 h (±6 h). The primary endpoint was the percentage of time that an adequate sedation depth was maintained, in the absence of rescue sedation, within the individually prescribed target range, as monitored every 2 h for an expected minimum of 12 h (up to 48±6 h) with the COMFORT-B scale. The primary endpoint was assessed for non-inferiority (margin -9·36 percentage points) in the full analysis set (all randomly assigned participants who received ≥6 h of the allocated study sedative and ≥3 masked COMFORT-B assessments), according to intention to treat. Safety was assessed in all participants who received study treatment. The trial was registered with ClinicalTrials.gov, NCT04684238, and EudraCT, 2020-000578-31, and is completed. FINDINGS: Between Jan 14, 2021, and Jan 19, 2023, 96 children were randomly assigned: 63 to the isoflurane group and 33 to the midazolam group. 92 participants were included in the full analysis set (mean age 7·7 years [SD 4·1]; 35 [38%] female and 57 [62%] male). The least-squares mean percentage of time in the COMFORT-B target range was 68·94% (95% CI 52·83-85·05) in the isoflurane group and 62·37% (44·70-80·04) in the midazolam group. The least-squares mean difference between treatments was 6·57 percentage points (95% CI -8·99 to 22·13), indicating non-inferiority, with the lower bound of the 95% CI exceeding the non-inferiority margin of -9·36 percentage points). In the safety set (n=94), serious adverse events occurred in 19 (31%) of 61 participants in the isoflurane group and eight (24%) of 33 participants in the midazolam group, none of which were considered related to study treatment. Treatment-related severe hypotension occurred in one participant per group, and three participants in the isoflurane group discontinued treatment due to adverse events. No treatment-related deaths were reported. INTERPRETATION: Among critically ill children, the effectiveness of sedation with inhaled isoflurane was non-inferior to that of intravenous midazolam, offering an alternative medication in children receiving mechanical ventilation. FUNDING: Sedana Medical, Stockholm, Sweden.

BACKGROUND: Blood products are limited resources and preoperative transfusion often relies on protocols or clinical experience rather than objective risk assessment. Thus a systematic and accurate prediction strategy is needed for efficient blood utilisation and timely administration. We developed and validated a nomogram to predict intraoperative red blood cell (RBC) transfusion. METHODS: We developed a nomogram that integrates preoperative variables to predict intraoperative RBC transfusion in patients undergoing major abdominal surgery at a tertiary care hospital (2012-21). The model was externally validated with datasets from other tertiary hospitals and an open dataset. Variables were selected using least absolute shrinkage or selection operator logistic regression. Discriminative ability was assessed with C-statistic, and calibration plots were used to evaluate the agreement between predicted and observed outcomes. RESULTS: This retrospective study included 128 749 patients for model development and 71 590 and 3701 patients in two external validation sets, respectively. Intraoperative RBC transfusion occurred in 6.0% of patients in the development set, and in 4.5% and 7.3% of patients in the two validation sets, respectively. The nomogram incorporated seven preoperative variables including age, American Society of Anesthesiologists physical status, European Society of Cardiology surgical risk, haemoglobin, concentration, platelet number, international normalised ratio, and albumin concentration. The nomogram showed good predictive ability with C-statistics of 0.857 (95% confidence interval [CI]: 0.852-0.861), 0.847 (95% CI: 0.840-0.854), and 0.848 (95% CI: 0.822-0.873) in the development and external validation sets, respectively, demonstrating good calibration across the predicted probability range. CONCLUSIONS: This nomogram, integrating seven preoperative variables, can effectively predict intraoperative transfusion in major abdominal surgery. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov (NCT06847490).

BACKGROUND: Adductor canal blocks (ACBs) reduce postoperative pain and opioid consumption for patients undergoing total knee arthroplasty (TKA); however, whether the optimal timing of the placement is preoperatively or immediately postoperatively remains unclear. The postoperative placement of an adductor canal block was hypothesized to have more favorable outcomes. METHODS: From September 2023 to January 2024, patients undergoing TKA with one of two surgeons were randomized to the experimental (postoperative) or control (preoperative) group. Clinical staff were blinded. Blocks utilized 20 mL ropivacaine 0.2%. All other institutional protocols remained unchanged. Pain (visual analog scale), opioids consumed (morphine milligram equivalents), nausea, and vomiting were recorded at two and 24 hours postoperatively. Length of stay and demographics (sex, age, laterality, body mass index, and anesthesia modality) were collected. An a priori power analysis demonstrated a need for 70 total patients. Mann-Whitney U- and Fisher's exact tests were utilized. Of 111 patients, 76% agreed to participate (47 preoperative and 37 postoperative). There were no differences in demographics. RESULTS: There were no differences between groups at two or 24 hours for pain, opioid consumption, patients who had nausea, and patients who had vomiting. No differences for length of hospital stay were observed for hours, nights, or the number of same-day or next-day discharges. An ACB for TKA performed preoperatively versus postoperatively did not affect patient postoperative pain, opioid consumption, nausea, vomiting, or length of stay. CONCLUSIONS: Preoperative logistics can be streamlined by having the option to place the ACB preoperatively or immediately postoperatively without concern for effects on patient pain, opioid consumption, or length of stay.