Daily Anesthesiology Research Analysis
Three perioperative studies stand out today: a randomized trial shows that preoperative intravenous dexamethasone reduces rebound pain and opioid use after wrist/hand surgery under supraclavicular block; a prospective pilot introduces a precise TEE-derived Renal Vein Flow Index that tracks systemic perfusion during cardiac surgery; and a meta-analysis finds superficial and deep parasternal intercostal plane blocks provide comparable analgesia after cardiac surgery.
Summary
Three perioperative studies stand out today: a randomized trial shows that preoperative intravenous dexamethasone reduces rebound pain and opioid use after wrist/hand surgery under supraclavicular block; a prospective pilot introduces a precise TEE-derived Renal Vein Flow Index that tracks systemic perfusion during cardiac surgery; and a meta-analysis finds superficial and deep parasternal intercostal plane blocks provide comparable analgesia after cardiac surgery.
Research Themes
- Perioperative analgesia optimization
- Intraoperative renal perfusion monitoring in cardiac surgery
- Regional anesthesia technique selection for sternotomy pain
Selected Articles
1. The effect of intravenous dexamethasone on rebound pain after wrist and hand surgery under supraclavicular brachial plexus blockade: a randomized placebo-controlled trial.
In a randomized, placebo-controlled trial (N=56), preoperative IV dexamethasone 0.11 mg/kg significantly reduced rebound pain incidence and severity and lowered 24-hour opioid consumption after wrist/hand surgery under supraclavicular block, without increasing postoperative complications.
Impact: Provides randomized evidence supporting a simple, low-cost intervention to mitigate rebound pain after peripheral nerve block, with opioid-sparing benefits.
Clinical Implications: Consider administering IV dexamethasone 0.11 mg/kg preoperatively for upper limb surgery under supraclavicular block to reduce rebound pain and opioid exposure, while monitoring for known steroid risks (e.g., hyperglycemia).
Key Findings
- Rebound pain incidence decreased from 79% (control) to 32% with IV dexamethasone (P<0.001).
- Mean rebound pain score difference was 2.6 points lower with dexamethasone (95% CI 1.5–3.7; P<0.001).
- 24-hour opioid consumption reduced from median 72 mg to 25 mg morphine equivalents with dexamethasone (P<0.001).
- No significant increase in postoperative complications observed.
Methodological Strengths
- Randomized, placebo-controlled design with trial registration (KCT0007208).
- Clinically meaningful outcomes (rebound pain and 24-hour opioid use) with clear statistical significance.
Limitations
- Single-center, small sample size (N=56) limits generalizability.
- Dose fixed at 0.11 mg/kg; no dose–response exploration and short follow-up (24 hours).
Future Directions: Multicenter RCTs with larger samples, longer follow-up, dose–response assessment, and evaluation across different block types and patient populations (e.g., diabetes) are warranted.
PURPOSE: We sought to evaluate the efficacy of intravenous dexamethasone in reducing rebound pain post-orthopedic wrist and hand surgery, administered prior to supraclavicular brachial plexus blockade. METHODS: We conducted a randomized placebo-controlled trial on 56 patients scheduled for elective wrist and hand surgery under supraclavicular brachial plexus blockade. We randomized participants into either a control group, receiving 0.9% of intravenous saline, or a dexamethasone group, receiving 0.11 mg·kg RESULTS: The mean (standard deviation [SD]) pain score difference was significantly larger in the control group (7.3 [1.9]) compared with the dexamethasone group (4.7 [2.1]), with a mean difference between groups of 2.6 (95% confidence interval, 1.5 to 3.7; P < 0.001). The incidence of rebound pain was also significantly higher in the control group (79% vs 32%; P < 0.001). The cumulative opioid consumption in 24 hr was greater in the control group than in the dexamethasone group (median [interquartile range (IQR)], 72 [54-97] mg vs 25 [14-60] mg; P < 0.001). We found no significant differences in postoperative complications. CONCLUSIONS: Preoperative administration of 0.11 mg·kg STUDY REGISTRATION: www.CRIS.nih.go.kr ( KCT0007208 ); first submitted 5 April 2022. RéSUMé: OBJECTIF: Nous avons cherché à évaluer l’efficacité de la dexaméthasone intraveineuse dans la réduction de la douleur de rebond après une chirurgie orthopédique du poignet et de la main, administrée avant un bloc du plexus brachial supraclaviculaire. MéTHODE: Nous avons mené une étude randomisée contrôlée par placebo sur 56 personnes devant bénéficier d’une chirurgie non urgente du poignet et de la main sous bloc du plexus brachial supraclaviculaire. Nous avons randomisé les participantes et participants en deux groupes : groupe témoin, recevant 0,9 % d’une solution saline intraveineuse, et groupe dexaméthasone, recevant 0,11 mg·kg
2. Assessment of Renal Vein Flow Index by Transesophageal Echocardiography: Precision, Variability, and Association with Cardiac Index During Cardiac Surgery.
This prospective pilot defined a TEE-based Renal Vein Flow Index (RVFI) and demonstrated excellent precision (measurement error 0.030; ICC 0.99) with dynamic intraoperative variability and a positive association with cardiac index during cardiac surgery.
Impact: Introduces a feasible, quantitative intraoperative index of renal venous flow that could enable goal-directed hemodynamic strategies to reduce CSA-AKI risk.
Clinical Implications: RVFI measurement by TEE could be integrated into intraoperative monitoring for high-risk cardiac surgery patients to assess renal venous congestion and perfusion in real time; outcome validation against CSA-AKI is needed before routine adoption.
Key Findings
- Defined and measured a Renal Vein Flow Index (RVFI) with TEE every 30 minutes across cardiac surgery.
- High measurement precision with error 0.030 units and ICC 0.99 across consecutive cardiac cycles.
- RVFI varied intraoperatively (range 0–1.0) and increased with higher cardiac index (positive association).
Methodological Strengths
- Prospective design with repeated measures and rigorous precision statistics (residual-based error, ICC).
- Objective linkage of RVFI to systemic perfusion using bootstrapped linear regression with CI.
Limitations
- Small single-center pilot (N=10) limits external validity.
- No assessment of downstream clinical outcomes (e.g., CSA-AKI incidence) or inter-operator feasibility.
Future Directions: Validate RVFI against CSA-AKI and renal congestion outcomes in multicenter cohorts; assess responsiveness to hemodynamic interventions and inter-operator reliability; define clinically actionable thresholds.
OBJECTIVES: Cardiac surgery-associated acute kidney injury (CSA-AKI) is a frequent and important complication often attributed to decreased kidney blood flow. Ultrasound measurement of renal vein blood flow has been associated with adverse cardiac outcomes but is understudied in cardiac surgery. The renal vein flow index (RVFI) was defined using transesophageal echocardiography (TEE) during cardiac surgery to assess its precision, variability throughout surgery, and relationship to systemic perfusion defined by the cardiac index (CI). DESIGN: Prospective. SETTING: University hospital. PARTICIPANTS: Patients undergoing cardiac surgery. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: RVFI was repeatedly measured using TEE every 30 minutes throughout the entire surgery. RVFI precision was assessed using measurement error estimated from RVFI residuals and intraclass correlation coefficient. To quantify the variability of RVFI over the course of surgery, box plots with medians and interquartile ranges were assessed. The relationship between CI and RVFI was analyzed using linear regression with bootstrapping. Data from 10 participants included 324 RVFI measurements from 108 ultrasound images. The estimated measurement error was 0.030 units, which was well below the clinically meaningful threshold of 0.1 units. The intraclass correlation coefficient was 0.99 for RVSI measurements obtained within three consecutive cardiac cycles. RVFI varied across surgery (range 0-1.0 units), and each CI increase of 0.5 L/min/m CONCLUSIONS: Intraoperative measurement of RVFI by TEE has excellent precision. TEE can detect a clinically meaningful change in RVFI. RVFI varied over the course of surgery and was associated with CI, consistent with expectations for a physiological measure of renal blood flow.
3. Efficacy of Superficial versus Deep Parasternal Intercostal Plane Blocks in Cardiac Surgery: A Systematic Review and Meta-Analysis.
This systematic review/meta-analysis (7 RCTs, 1 observational; N=510) found no significant differences between superficial and deep parasternal intercostal plane blocks in 24-hour opioid use, pain scores, PONV, time to rescue analgesia, extubation time, or ICU length of stay after cardiac surgery.
Impact: Clarifies that both parasternal plane block approaches yield comparable analgesia, enabling practice to prioritize patient anatomy, safety, and operator expertise rather than block depth.
Clinical Implications: Either S-PIP or D-PIP can be used for sternotomy analgesia with similar outcomes; selection may be based on technical familiarity, anticoagulation status, ultrasound visibility, and institutional protocols.
Key Findings
- Across 510 patients (7 RCTs + 1 observational), no significant difference in 24-hour opioid MME between S-PIP and D-PIP (MD -1.23; 95% CI -2.51 to 0.05; p=0.061).
- No differences in resting/movement pain scores at 0, 6, 12, 24 hours.
- No differences in PONV incidence, time to first analgesic, extubation time, or ICU length of stay.
Methodological Strengths
- Comprehensive multi-database search including ClinicalTrials.gov and inclusion of multiple RCTs.
- Standardized primary outcome (24-hour MME) with multiple clinically relevant secondary endpoints.
Limitations
- Potential heterogeneity in block techniques, local anesthetic regimens, and perioperative pathways across trials.
- Risk-of-bias details and PRISMA compliance not specified in the abstract; limited granularity on safety endpoints.
Future Directions: Head-to-head RCTs with uniform protocols, safety assessments (e.g., pleural puncture, vascular injury), and cost-effectiveness analyses to refine block selection.
OBJECTIVES: To compare the analgesic efficacy of superficial parasternal intercostal plane (S-PIP) block and deep parasternal intercostal plane (D-PIP) to determine which technique provides superior pain relief in cardiac surgery. DESIGN: A systematic search of MEDLINE (via PubMed), Scopus, Embase, Cochrane Library, Web of Science, Google Scholar, and ClinicalTrials.gov from inception until January 18, 2025. Eligible studies included randomized controlled trials (RCTs) and observational studies that compared the S-PIP and D-PIP blocks in patients undergoing cardiac surgery. The primary outcome of the study was postoperative opioid consumption of morphine milligram equivalent (MME) at 24 hours. Secondary outcomes included resting and movement pain scores at 0, 6, 12 and 24 hours, time to first analgesics, incidence of postoperative nausea and vomiting (PONV), extubation time, length of stay (LOS) in the intensive care unit (ICU), and the number of patients requiring rescue analgesics. MAIN RESULTS: Seven RCTs and 1 observational study, including a total of 510 patients, were identified. The findings demonstrated no statistically significant difference in MME at 24 hours between the S-PIP and D-PIP block groups (mean difference, -1.23; 95% confidence interval, -2.51 to 0.05; p = 0.061). Additionally, there were no significant differences in pain scores, PONV incidence, time to rescue analgesics, extubation time, or ICU LOS of stay between the 2 techniques. CONCLUSIONS: S-PIP and D-PIP blocks provide comparable postoperative analgesic efficacy in patients undergoing cardiac surgery.