Daily Anesthesiology Research Analysis
Three studies advance perioperative safety and outcomes in anesthesiology: a large multicenter RCT shows capnography monitoring reduces hypoxia during propofol sedation for GI endoscopy in older adults; a multicenter RCT demonstrates that adding glycopyrronium to standard antiemetic prophylaxis lowers postoperative nausea and vomiting; and a prospective cohort provides actionable perioperative fluid balance thresholds linked to major complications in advanced ovarian cancer cytoreduction.
Summary
Three studies advance perioperative safety and outcomes in anesthesiology: a large multicenter RCT shows capnography monitoring reduces hypoxia during propofol sedation for GI endoscopy in older adults; a multicenter RCT demonstrates that adding glycopyrronium to standard antiemetic prophylaxis lowers postoperative nausea and vomiting; and a prospective cohort provides actionable perioperative fluid balance thresholds linked to major complications in advanced ovarian cancer cytoreduction.
Research Themes
- Perioperative monitoring to prevent hypoxia during sedation
- Antiemetic optimization with anticholinergic adjuvant
- Goal-directed fluid management in major oncologic surgery
Selected Articles
1. Capnography monitoring reduces incidence of hypoxia in older patients undergoing gastrointestinal endoscopy under propofol sedation.
In a multicenter randomized, single-blind trial of 1,777 older adults undergoing GI endoscopy with propofol sedation, adding capnography to standard monitoring reduced hypoxia from 19% to 12%. The trial supports routine capnography to enhance respiratory safety during sedation in older patients.
Impact: This large, pragmatic RCT provides definitive evidence that capnography reduces hypoxia during procedural sedation in an at-risk population, informing monitoring standards for endoscopy suites.
Clinical Implications: Endoscopy units caring for older adults under propofol sedation should incorporate capnography into routine monitoring to reduce hypoxia and potentially prevent escalation of care.
Key Findings
- Multicenter randomized, single-blind trial across three hospitals enrolled 1,777 older adults (65–79 years).
- Capnography reduced hypoxia incidence from 19% (control) to 12% (intervention).
- Standardized propofol sedation with predefined hypoxia thresholds enabled consistent outcome assessment.
Methodological Strengths
- Multicenter randomized, single-blind, superiority design with large sample size.
- Predefined primary and secondary hypoxia thresholds and active comparator monitoring.
Limitations
- Single-blind design; clinicians were aware of monitoring assignment.
- Restricted to older adults under propofol; generalizability to other ages/sedatives is uncertain.
Future Directions: Evaluate capnography’s impact on severe hypoxia, rescue interventions, and cost-effectiveness across broader sedation strategies and age groups.
BACKGROUND AND STUDY AIMS: Whether routine capnography monitoring during gastrointestinal endoscopy sedation can reduce occurrence of hypoxia is controversial. Older patients are more prone to hypoxia. This study aimed to determine the effect of additional capnography monitoring on incidence of hypoxia in older patients undergoing gastrointestinal endoscopy under propofol sedation. PATIENTS AND METHODS: A multicenter, randomized, single-blind, two-arm, parallel-group, controlled with an active comparator, interventional superiority clinical trial was performed at three teaching hospitals in China between September 1, 2021, and September 1, 2022. This study compared additional capnography monitoring (intervention group) and standard monitoring (control group) among older patients (aged 65-79 years) undergoing gastrointestinal endoscopy under propofol sedation. The primary outcome was incidence of hypoxia (75%-89% for < 60s). Secondary outcomes were incidence of subclinical hypoxia (90%-94%), incidence of severe hypoxia (< 75% for any duration or 75%-89% for ≥ 60s), and other adverse events (AEs). RESULTS: Data from 1777 participants (888 intervention, 889 control group) were analyzed. Additional capnography monitoring reduced incidence of hypoxia in older patients from 19% to 12% ( CONCLUSIONS: Additional capnography monitoring during gastrointestinal endoscopy for older patients who were sedated with propofol reduces incidence of hypoxia.
2. Effects of Glycopyrronium Bromide as an Adjuvant Treatment in the Prevention of Nausea and Vomiting After Abdominal, Thyroid, and Breast Surgery: A Multicenter Randomized Controlled Trial.
Across 11 hospitals and 471 surgical patients receiving postoperative opioids, adding 0.2 mg glycopyrronium bromide to standard dexamethasone+tropisetron prophylaxis reduced PONV (27.8% vs 43.0%; OR 0.65, 95% CI 0.50–0.83). This supports anticholinergic augmentation of antiemetic regimens in general anesthesia.
Impact: A pragmatic multicenter RCT identifies a low-cost, widely available adjuvant that meaningfully reduces PONV despite modern dual prophylaxis.
Clinical Implications: Consider adding 0.2 mg IV glycopyrronium at the end of surgery for patients at risk of PONV who will receive postoperative opioids, alongside guideline-based antiemetics.
Key Findings
- Multicenter RCT across 11 hospitals with 471 patients under general anesthesia receiving postoperative opioids.
- PONV incidence decreased from 43.0% (control) to 27.8% (glycopyrronium group), OR 0.65 (95% CI 0.50–0.83).
- Broad surgical mix (gynecologic, gastrointestinal, thyroid, breast), supporting external applicability.
Methodological Strengths
- Randomized, multicenter design with active standard-of-care comparator.
- Prespecified primary outcome and effect estimates with confidence intervals.
Limitations
- Heterogeneity of procedures and anesthetic practices across sites.
- Anticholinergic side-effect profile beyond immediate postoperative period not fully reported.
Future Directions: Head-to-head comparisons with other adjuvants, dose-response studies, and inclusion in multimodal PONV risk-stratified protocols.
BACKGROUND: Effective methods for the prevention of postoperative nausea and vomiting remain to be found. Building upon previous evidence, we examined whether glycopyrrolate bromide had a preventive effect on nausea and vomiting when used as an adjuvant treatment. METHODS: In 11 participating hospitals, patients who were scheduled to receive gynecological (n=123), gastrointestinal (n=201), thyroid (n=93), and breast surgery (n=51) under general anesthesia and received postoperative opioids were randomly allocated to receive 4 mg dexamethasone and 4 mg tropisetron (Group C) or 4 mg dexamethasone and 4 mg tropisetron combined with 0.2 mg glycopyrrolate bromide (Group G). The primary outcome of postoperative nausea and vomiting was assessed. The secondary outcomes included the incidences of significant nausea and vomiting (defined based on a rating scale of intensity ≥ 4), vomiting, and extra intervention. RESULTS: In total, 471 patients (234 in Group G and 237 in Group C) were included in the final analysis. The incidence of postoperative nausea and vomiting in Group G was lower than that in Group C (27.8% vs 43.0%, odds rate=0.65, 95% confidence interval =0.50-0.83, CONCLUSION: The intravenous administration of 0.2 mg glycopyrronium bromide at the end of surgery can be an effective adjuvant treatment strategy for prevention of nausea and vomiting in patients undergoing surgery under general anesthesia and receiving postoperative opioids. TRIAL REGISTRATION: The Hospital Ethics Committee of the Second Affiliated Hospital, Chongqing Medical University (Approval ID: 2022-14-1) approved this study. This trial was registered with Identifier NCT05331651 on ClinicalTrials.gov.
3. Prospective Assessment of Clinically Relevant Fluid Balance Thresholds Associated With Postoperative Complications in Advanced Ovarian Cancer.
In a prospective cohort of 162 patients undergoing upfront cytoreductive surgery for advanced ovarian cancer, positive perioperative fluid balance of 1,750–2,700 mL (OR 3.40) and >2,700 mL (OR 3.91) was associated with higher odds of major complications. Targets of <1,750 mL (or <2,700 mL if initial ascites is counted as loss) provide pragmatic guidance for fluid management.
Impact: Defines data-driven fluid balance thresholds linked to major complications in a high-risk oncologic surgery, addressing a common but under-specified anesthetic decision domain.
Clinical Implications: Aim for a perioperative 24-hour fluid balance <1.75 L in cytoreductive surgery for advanced ovarian cancer; if including initial ascites as loss, maintain <2.7 L to reduce major complications.
Key Findings
- Prospective observational study included 162 patients undergoing upfront cytoreductive surgery.
- Positive fluid balance 1,750–2,700 mL and >2,700 mL increased odds of major complications (adjusted OR 3.40 and 3.91, respectively).
- When counting initial ascites as fluid loss, >2,700 mL remained associated with higher complication odds (OR 2.59).
Methodological Strengths
- Prospective design with a priori defined fluid balance cut-offs and multivariable adjustment.
- Clinically homogeneous high-risk cohort and pragmatic perioperative measurements.
Limitations
- Observational design precludes causal inference.
- Single-country setting; moderate sample size limits subgroup analyses.
Future Directions: Randomized or stepped-wedge trials testing fluid balance targets and integration with goal-directed hemodynamic therapy; external validation across centers and tumor types.
BACKGROUND: Reliable data on optimal fluid management in the perioperative period for patients with advanced ovarian cancer undergoing cytoreductive surgery is limited. These patients often present with malignant ascites and are prone to significant fluid shifts perioperatively. For this reason, our objective was to define clinical targets for optimal fluid balance and determine whether initial ascites should be included in fluid-loss calculations by examining the association between perioperative fluid balance and major postoperative complications. METHODS: This prospective, observational study conducted in a centralized and public healthcare system setting in Sweden between 2020 and 2023 included patients with advanced ovarian cancer, > 18 years of age, scheduled for upfront cytoreductive surgery, an ASA physical status I-III with no speech/language issues. The primary outcome was major postoperative complication within 30 days of surgery. The measurements of fluid input and output, cut-offs for fluid balance, perioperative time, and postoperative complications were defined a priori. The association between fluid balance and major postoperative complications was assessed by multivariable regression, adjusted for predefined covariates, yielding odds ratios (OR) with 95% confidence intervals (CI). RESULTS: Of 175 enrolled patients, 162 were included in the final analysis. In the adjusted analysis, there was a significant association between fluid balance of 1750-2700 mL, OR 3.40 (95% CI 1.06-10.9; p = 0.04) and > 2700 mL, OR 3.91 (95% CI 1.33-11.5; p = 0.01) and major postoperative complications. When including initial ascites as fluid loss, a balance of > 2700 mL was associated with major postoperative complications, OR 2.59 (95% CI 1.01-6.66, p = 0.047). CONCLUSION: An optimal target for perioperative fluid balance to decrease the odds of major postoperative complications is suggested to be < 1750 mL. If initial ascites is included as loss in the calculation of balance, the optimal target of fluid balance is suggested to be < 2700 mL. These results provide practical clinical reference values that may assist anesthesiologists and surgical teams in optimizing perioperative fluid management in advanced ovarian cancer. EDITORIAL COMMENT: This secondary analysis of a trial ovarian cancer operative cohort assessed the relation of the estimated fluid balance over the operative day 24 h to major postoperative complications. The findings showed that the groups where the fluid balance was in the categories higher and also most positive had higher odds for having a major complication compared to the group with lowest fluid balance. Ascities fluid was an issue in this cohort, which was managed in the analysis. TRIAL REGISTRATION: ClinicalTrials.gov: NCT04065009.