Daily Anesthesiology Research Analysis
Three perioperative studies stand out today: a double-blind RCT (PRESSURE trial) shows that lowering central venous pressure during minimally invasive liver resection does not reduce blood loss and increases intraoperative instability; a meta-analysis of RCTs finds videolaryngoscopy markedly improves intubation success and reduces hypoxemia in class 2–3 obesity; and a large cohort study links preoperative anemia to higher postoperative delirium and long-term mortality in older non-cardiac surgic
Summary
Three perioperative studies stand out today: a double-blind RCT (PRESSURE trial) shows that lowering central venous pressure during minimally invasive liver resection does not reduce blood loss and increases intraoperative instability; a meta-analysis of RCTs finds videolaryngoscopy markedly improves intubation success and reduces hypoxemia in class 2–3 obesity; and a large cohort study links preoperative anemia to higher postoperative delirium and long-term mortality in older non-cardiac surgical patients.
Research Themes
- Perioperative hemodynamic strategies in minimally invasive liver surgery
- Airway management optimization in obesity using videolaryngoscopy
- Preoperative risk stratification: anemia and postoperative delirium
Selected Articles
1. Reduction of Central Venous Pressure in Elective Robotic and Laparoscopic Liver Resection: The PRESSURE Trial-A Randomized Clinical Study.
In this double-blind RCT of 112 patients undergoing minimally invasive liver resection, deliberate CVP reduction did not decrease intraoperative blood loss but increased intraoperative hemodynamic instability. Ninety-day mortality and overall morbidity were similar between groups.
Impact: This trial challenges the long-standing practice of CVP reduction during MILR by showing no hemostatic benefit and more instability, directly informing anesthetic fluid and hemodynamic strategies.
Clinical Implications: Avoid routine CVP-lowering strategies in MILR; prioritize hemodynamic stability over aggressive fluid restriction/venodilation. Maintain standard anesthetic care and use other blood-sparing techniques.
Key Findings
- Total intraoperative blood loss was equivalent with and without CVP reduction: 280 mL (120–560) vs 360 mL (150–640); P=0.30.
- CVP was higher without reduction during resection (9.3±4.2 vs 3.2±2.2 mmHg; P<0.001), yet blood loss during transection was similar (220 vs 240 mL; P=0.39).
- Intraoperative hemodynamic instability was less frequent without CVP reduction (12% vs 30%; P=0.03); 90-day mortality (5% vs 4%; P=0.68) and morbidity (18% vs 20%; P=0.77) were comparable.
Methodological Strengths
- Randomized, double-blind design with equal allocation and standardized perioperative care
- Clinically meaningful primary endpoint (total intraoperative blood loss) with prespecified analyses
Limitations
- Single RCT with 112 analyzed patients may be underpowered for rare outcomes
- Findings limited to elective minimally invasive liver resections; generalizability to open or high-risk cases uncertain
Future Directions: Multicenter trials to confirm findings, explore patient subgroups (cirrhosis, large resections), and test alternative blood-sparing strategies that preserve hemodynamic stability.
OBJECTIVE: To compare perioperative outcomes in patients undergoing minimally invasive liver surgery (MILR) with or without central venous pressure (CVP) reduction (≤5 mm Hg). BACKGROUND: Reduction of CVP during parenchymal transection is widely accepted in open hepatectomy to reduce intraoperative blood loss, as a major predictor of postoperative outcomes. However, the effect of CVP reduction on blood loss in MILR remains unclear. METHODS: This study is a randomized controlled, double-blinded trial. Patients undergoing elective MILR between August 2020 and April 2023 were equally randomized to either no CVP reduction (No CVP reduct
2. Videolaryngoscopy vs. direct laryngoscopy in class 2 and 3 obesity: a systematic review, meta-analysis and trial sequential analysis of randomised controlled trials.
Across 10 RCTs (n=955) in class 2–3 obesity, videolaryngoscopy markedly reduced failed tracheal intubation (RR 0.15), hypoxemia (RR 0.21), and first-attempt failure (RR 0.44), with better glottic views and no meaningful increase in intubation time or sore throat.
Impact: Provides high-level evidence to standardize first-line use of videolaryngoscopy in high-BMI patients, addressing a major source of airway complications.
Clinical Implications: Adopt videolaryngoscopy as first-line for intubation in class 2–3 obesity to reduce hypoxemia and failed attempts; ensure training and device availability.
Key Findings
- Failed tracheal intubation reduced with videolaryngoscopy (RR 0.15 [0.05–0.35], p<0.001; nine studies).
- Hypoxemia reduced (RR 0.21 [0.10–0.43], p<0.001; seven studies) and first-attempt failure reduced (RR 0.44 [0.25–0.76], p=0.004).
- Improved glottic visualization without significant differences in intubation time, sore throat, or intubation difficulty scale.
Methodological Strengths
- Systematic review and meta-analysis restricted to RCTs with trial sequential analysis
- Predefined primary and secondary outcomes across multiple trials
Limitations
- Heterogeneity in videolaryngoscope models and operator experience across trials
- Predominantly elective general surgery; applicability to emergent airways or ICU may differ
Future Directions: Head-to-head comparisons of videolaryngoscope types in severe obesity, evaluation in emergency/ICU settings, and cost-effectiveness analyses.
INTRODUCTION: The 7th National Audit Project of the Royal College of Anaesthetists revealed an increase in rates of tracheal intubation over the last decade, partially contributed to by the rise in people living with obesity. Notably, airway and respiratory complications were over-represented in patients living with class 2 or 3 obesity (BMI ≥ 35 kg.m METHODS: We conducted a systematic review and meta-analysis of randomised controlled trials published in the last 15 years. We searched five databases for trials comparing videolaryngoscopy with direct laryngoscopy in adult patients living with class 2 or 3 obesity undergoing elective general surgery. Primary outcomes were the incidence of failed tracheal intubation; hypoxaemia; and first attempt tracheal intubation failure. Secondary outcomes were glottic visualisation; time to tracheal intubation; incidence of sore throat; and intubation difficulty scale. RESULTS: We included 10 trials with 955 patients, of whom 481 received videolaryngoscopy and 474 direct laryngoscopy. Videolaryngoscopy significantly reduced failed tracheal intubation (relative risk (95%CI) 0.15 (0.05-0.35), p < 0.001, nine studies); hypoxaemia (relative risk (95%CI) 0.21 (0.10-0.43), p < 0.001, seven studies); and first attempt failure (relat
3. Association between preoperative anemia and postoperative delirium in elderly patients undergoing non-cardiac surgery: a retrospective observational study.
In 62,600 elderly non-cardiac surgical patients, preoperative anemia was associated with a higher risk of postoperative delirium (OR 1.42) in an IPTW-adjusted analysis, with a severity-dependent increase. Similar associations were seen for 1- and 3-year mortality.
Impact: Identifies preoperative anemia as a strong, potentially modifiable risk factor for delirium and mortality, informing prehabilitation and perioperative optimization.
Clinical Implications: Incorporate hemoglobin screening and anemia management into preoperative assessments for older adults; consider iron/ESA strategies and delirium prevention bundles in anemic patients.
Key Findings
- Preoperative anemia increased POD risk within 7 days (OR 1.42, 95% CI 1.30–1.55; P<0.001) after IPTW adjustment.
- Dose–response by severity: mild anemia OR 1.32 (95% CI 1.18–1.47), moderate-to-severe anemia OR 1.70 (95% CI 1.50–1.93); both P<0.001.
- Similar associations with 1- and 3-year mortality, highlighting long-term prognostic implications.
Methodological Strengths
- Very large cohort (n=62,600) with inverse probability of treatment weighting to control confounding
- Severity stratification of anemia and assessment of both short- and long-term outcomes
Limitations
- Retrospective design with potential residual confounding and misclassification of delirium
- Single-country data; external validity to different practice settings may vary
Future Directions: Prospective interventional trials testing anemia optimization (iron, ESA, transfusion thresholds) on delirium and mortality; integration into multimodal prehabilitation.
BACKGROUND: The association between preoperative anemia and postoperative delirium (POD) is unclear. We sought to evaluate the effect of preoperative anemia on the risk of POD in elderly patients after non-cardiac surgery. METHODS: We retrospectively analyzed 62 600 patients aged over 60 years undergoing non-cardiac surgery between January 2011 and June 2019. The patients were divided into two groups according to the presence of preoperative anemia defined as hemoglobin < 13 g/dl for men and < 12 g/dl for women. Anemia was further categorized into mild or moderate-to-severe anemia based on a cutoff of 11 g/dl. The primary outcome was POD within 7 days after surgery. The secondary outcomes included one- and three-year mortality after surgery. The inverse probability of treatment weighting (IPTW) method was used to adjust for confounders between the two groups. RESULTS: The overall incidence of POD was 3.9% (2447/62 600) within 7 days after surgery. After IPTW, preoperative anemia was significantly associated with increased risk of POD (odds ratio [OR]: 1.42, 95% CI [1.30-1.55], P < 0.001). Also, the risk of POD increased with the severity of anemia (OR: 1.32, 95% CI [1.18-1.47], P < 0.001 for mild anemia; and OR: 1.70, 95% CI [1.50-1.93], P < 0.001 for moderate-to-severe anemia). This association was similar for one- and three-year mortality. CONCLUSIONS: Preoperative anemia was associated with an increased risk of POD in elderly patients after non-cardiac surgery. Further investigations are required to verify whether preoperative anemia is a modifiable risk factor for POD.