Daily Anesthesiology Research Analysis
Three anesthesia-focused studies stand out today: a randomized trial shows intraoperative lidocaine (intravenous or paravertebral) reduces major and pulmonary complications versus remifentanil during lung resection; a large propensity-matched cardiac surgery cohort links acute normovolemic hemodilution to substantially fewer transfusions with cost savings; and a meta-analysis of 68 RCTs finds opioid-free anesthesia halves PONV risk and reduces rescue analgesia and pain scores.
Summary
Three anesthesia-focused studies stand out today: a randomized trial shows intraoperative lidocaine (intravenous or paravertebral) reduces major and pulmonary complications versus remifentanil during lung resection; a large propensity-matched cardiac surgery cohort links acute normovolemic hemodilution to substantially fewer transfusions with cost savings; and a meta-analysis of 68 RCTs finds opioid-free anesthesia halves PONV risk and reduces rescue analgesia and pain scores.
Research Themes
- Opioid-sparing and anti-inflammatory anesthesia strategies
- Blood conservation and transfusion stewardship in cardiac surgery
- Perioperative outcomes: PONV mitigation and complication reduction
Selected Articles
1. Effect of intraoperative paravertebral or intravenous lidocaine infusion on postoperative complications and inflammation after lung resection surgery: a randomised controlled trial.
In 154 VATS lung resection patients, intraoperative lidocaine (either intravenous or paravertebral infusion) reduced major complications (3.7–4.1% vs 11.8%) and pulmonary complications (22.3% vs 45.1%) compared with remifentanil, and attenuated cytokine elevations after one-lung ventilation. Benefits were similar via both routes, consistent with anti-inflammatory effects.
Impact: This RCT provides compelling evidence that a lidocaine-based intraoperative strategy improves hard postoperative outcomes versus remifentanil in thoracic surgery, aligning mechanistic cytokine data with clinical benefit.
Clinical Implications: Consider incorporating intravenous or paravertebral lidocaine infusions into multimodal thoracic anesthesia to reduce major and pulmonary complications, with attention to dosing and monitoring; remifentanil-based regimens may be de-emphasized when lidocaine is feasible.
Key Findings
- Lidocaine (IV or paravertebral) reduced major complications vs remifentanil (3.7–4.1% vs 11.8%; P=0.037; OR 0.44, 95% CI 0.22–0.88).
- Pulmonary complications were lower with lidocaine (22.3%) than remifentanil (45.1%; OR 0.35, 95% CI 0.17–0.72; P=0.004).
- Post–one-lung ventilation cytokine levels were reduced with lidocaine, suggesting anti-inflammatory mediation.
Methodological Strengths
- Randomized controlled design comparing two lidocaine routes against an active comparator (remifentanil).
- Integrated mechanistic assessment via cytokines in BAL fluid and plasma alongside clinical endpoints.
Limitations
- Single-center trial with moderate sample size may limit generalizability.
- Comparator limited to remifentanil; not a head-to-head against other multimodal opioid-sparing regimens.
Future Directions: Multicenter trials to validate generalizability, optimal dosing/monitoring protocols for lidocaine, and evaluation across open thoracotomy and broader ERAS pathways.
BACKGROUND: The potential for the anti-inflammatory effects of lidocaine to reduce complications after lung resection has not been evaluated. We assessed whether intraoperative i.v. or paravertebral lidocaine, compared with remifentanil, reduced complications after lung resection. We also quantified pulmonary and systemic inflammatory responses. METHODS: This single-centre study randomised participants undergoing lung resection (video-assisted thoracoscopy) to receive continuous infusion of either (1) i.v. lidocaine and paravertebral saline, (2) paravertebral lidocaine and i.v. saline, or (3) remifentanil and paravertebral saline. The primary outcome was the proportion of participants with all-cause complications (Clavien-Dindo classification). Cytokines were measured in bronchoalveolar lavage fluid before and after one-lung ventilation and in plasma during the first 24 h. RESULTS: In 154 patients (mean age 65 yr; 42% female), fewer major (Clavien-Dindo Grade ≥III) complications were recorded in participants randomised to intraoperative paravertebral (two of 49; 4.1%) or i.v. (two of 54; 3.7%) lidocaine, compared with six of 51 (11.8%) participants who received remifentanil (P=0.037). Severe complications were less likely with lidocaine from either i.v. or paravertebral sources, compared with remifentanil (odds ratio: 0.44 [95% confidence interval: 0.22-0.88]). Pulmonary complications occurred in 23/103 (22.3%) participants allocated to intraoperative lidocaine from either i.v. or paravertebral routes, compared with 23/51 (45.1%) participants who received remifentanil (odds ratio: 0.35 [95% confidence interval: 0.17-0.72]; P=0.004). Cytokine levels after one-lung ventilation were lower with lidocaine treatment. CONCLUSIONS: Intraoperative lidocaine infusion administered either intravenously or through paravertebral catheter reduces the incidence and severity of complications after lung resection surgery compared with remifentanil. Lidocaine might confer this benefit through reducing systemic and lung inflammation. CLINICAL TRIAL REGISTRATION: NCT03905837.
2. Impact of the absence of opioid anesthesia on postoperative outcome indicators: a systematic review and meta-analysis.
Across 68 RCTs (n=5,426), opioid-free anesthesia halved PONV risk, reduced nausea/vomiting individually, lowered need for postoperative rescue analgesia (RR 0.61), and modestly reduced 24-hour pain scores. Heterogeneity was high for some endpoints, and broader recovery benefits require confirmation.
Impact: This comprehensive synthesis provides high-level evidence supporting OFA to reduce PONV and analgesic demand across varied surgeries, informing perioperative protocols and patient-centered outcomes.
Clinical Implications: In patients at high PONV risk, consider OFA within multimodal strategies, balancing benefits against potential hemodynamic effects; standardize protocols and monitoring while awaiting further safety-focused trials.
Key Findings
- OFA reduced PONV vs OBA (RR 0.50, 95% CI 0.39–0.64).
- Lower need for postoperative rescue analgesia with OFA (RR 0.61, 95% CI 0.51–0.72).
- 24-hour postoperative pain scores were modestly lower (SMD −0.32, 95% CI −0.53 to −0.10).
Methodological Strengths
- Large-scale meta-analysis restricted to randomized controlled trials.
- Broad inclusion across surgical types enhances external validity for perioperative practice.
Limitations
- High heterogeneity for some endpoints; limited safety and long-term outcome data reported.
- Variability in OFA protocols and adjuncts may confound pooled estimates.
Future Directions: Standardized OFA protocols with rigorous safety monitoring in multicenter RCTs, including hemodynamic and recovery quality endpoints, and subgroup analyses by surgical type and risk profile.
OBJECTIVE: This study aimed to examine the effect of opioid-free anesthesia (OFA) on postoperative outcome indicators and explore its application in thoracoscopic or laparoscopic as well as non-thoracoscopic or laparoscopic surgeries, providing a scientific basis for clinical decision-making. METHOD: A systematic search was conducted for clinical studies comparing OFA and opioid-based anesthesia (OBA) published from the establishment of the databases to May 2025 using databases such as PubMed, Web of Science, Embase, and Cochrane Library. The primary outcome was the incidence of postoperative nausea and vomiting (PONV). Secondary outcomes included perioperative recovery indicators, the need for postoperative emergency analgesia, postoperative pain score (VAS, NRS), and adverse reactions. RESULTS: A total of 3,766 relevant studies were initially identified, and 68 randomized controlled trials involving 5,426 patients were ultimately included. Compared with OBA, OFA significantly reduced the risks of PONV (RR = 0.50, 95% CI: 0.39-0.64), nausea alone (RR = 0.34, 95% CI: 0.25-0.46), vomiting alone (RR = 0.34, 95% CI: 0.25-0.46), and the need for postoperative emergency analgesia (RR = 0.61, 95% CI: 0.51-0.72). OFA was also associated with lower 24 h postoperative NRS pain scores (SMD = -0.32, 95% CI: -0.53 to -0.10). For outcomes with high heterogeneity ( CONCLUSION: In summary, OFA not only significantly reduces postoperative PONV, but also lowers the demand for analgesic drugs and improves the quality of postoperative recovery. However, its effect on some postoperative recovery indicators is limited, and further high-quality studies are required to confirm these findings. OFA is expected to serve as a safe and effective anesthesia strategy to optimize the perioperative outcomes of patients.
3. Acute Normovolemic Hemodilution in Adult Cardiac Surgery.
In a propensity score–matched analysis of 16,795 CPB cases, ANH use (14.7%) was associated with lower odds of any transfusion (OR 0.73) and fewer RBC and non-RBC units, with stronger effects at ≥650 mL. Cost estimates favored ANH, underscoring its safety and underuse as a blood conservation strategy.
Impact: This contemporary, national cohort provides actionable, volume-dependent evidence supporting ANH to reduce transfusions and costs in cardiac surgery, addressing blood supply vulnerabilities and perioperative stewardship.
Clinical Implications: Cardiac anesthesia teams should consider routine ANH in suitable CPB cases, targeting higher volumes (≥650 mL) when safe, to reduce RBC and non-RBC transfusions and associated costs; implement protocols and training to increase adoption.
Key Findings
- After propensity score matching (n=2,282 pairs), ANH reduced any transfusion (31.2% vs 36.4%; OR 0.73, 95% CI 0.60–0.89).
- High-volume ANH (≥650 mL) further reduced odds of RBC and non-RBC transfusions by 47–64%.
- Fewer erythrocyte (−167 units) and platelet (−295 units) transfusions cumulatively with ANH, with lower acquisition and activity-based costs.
Methodological Strengths
- Large national database with rigorous propensity score matching.
- Volume–response analysis and cost estimates enhance practical relevance.
Limitations
- Observational design limits causal inference despite matching; residual confounding possible.
- ANH documentation and selection practices may vary across sites.
Future Directions: Pragmatic multicenter RCTs to confirm causality, define optimal volume targets, and evaluate patient-centered outcomes; implementation studies to overcome adoption barriers.
IMPORTANCE: Acute normovolemic hemodilution (ANH) is a well-known blood conservation technique, yet its adoption in the US remains low (<20%), and cardiac surgery remains the largest consumer of blood components. Increasing vulnerabilities in the US blood supply underscore the need to reassess ANH effectiveness in blood conservation. OBJECTIVE: To evaluate ANH use in perioperative transfusion and blood component use in patients undergoing surgery with cardiopulmonary bypass (CPB). DESIGN, SETTING, AND PARTICIPANTS: A retrospective propensity-score matched cohort study using data from the Society of Thoracic Surgeons (STS) Adult Cardiac Surgery Database (version 4.20.2). The study included adult patients (≥18 years) undergoing coronary artery bypass grafting (CABG) and/or valve surgery with CPB (July 2020 to September 2023). EXPOSURE: The primary exposure was ANH, defined as any recorded use/volume in the STS database. MAIN OUTCOME AND MEASURES: The primary outcome was intraoperative or postoperative transfusion of any blood component. The volume-dependent ANH effect estimate was also assessed using a cutoff value of 650 mL. Secondary outcomes included the total number of transfused red blood cells (RBC) and non-RBC components (platelets, plasma, and cryoprecipitate); bleeding reexplorations; length of stay in the intensive care unit; and estimates for blood acquisition and activity-based costs. RESULTS: Among 16 795 patients (mean [SD] age, 65.3 [10.5] years; 12 114 male [72.1%]), ANH was reported in 2463 cases (14.7%). Patients receiving ANH had a significantly lower preoperative anemia rate and higher baseline hematocrit (mean difference: 2.5%; 95% CI, 2.3-2.7; P < .001). After propensity score matching (n = 2282 pairs), transfusion rates were significantly lower in the ANH group (31.2% vs 36.4%; P < .001). ANH was associated with 27% lower odds of any transfusion (odds ratio, 0.73; 95% CI, 0.60-0.89). High-volume ANH (≥650 mL) further reduced the odds of transfusion by 47% to 64% for both RBC and non-RBC components. The cumulative number of transfused erythrocyte and platelet units was 167 and 295 units lower, respectively, in the ANH group compared with the control group, with lower estimates for both acquisition and activity-based costs. CONCLUSIONS AND RELEVANCE: In this study, a volume-dependent association was found between ANH and reduced RBC and non-RBC transfusion rates in patients undergoing cardiac surgery. Despite being safe and cost-effective, ANH remains underused as a blood conservation strategy.