Daily Anesthesiology Research Analysis
Three perioperative studies stand out today: a large meta-analysis quantifying postoperative AKI burden and showing individualized blood pressure targets reduce AKI; an observational study suggesting intraoperative autologous blood transfusion during oncologic resection is not linked to early metastasis or worse survival; and a decade-long multicenter analysis showing doubled use of noninvasive respiratory support after pediatric extubation with a modest reduction in reintubation.
Summary
Three perioperative studies stand out today: a large meta-analysis quantifying postoperative AKI burden and showing individualized blood pressure targets reduce AKI; an observational study suggesting intraoperative autologous blood transfusion during oncologic resection is not linked to early metastasis or worse survival; and a decade-long multicenter analysis showing doubled use of noninvasive respiratory support after pediatric extubation with a modest reduction in reintubation.
Research Themes
- Perioperative organ protection and hemodynamic strategies
- Blood management and oncologic safety in surgery
- Pediatric extubation and noninvasive respiratory support practices
Selected Articles
1. Incidence and risk factors of acute kidney injury after abdominal surgery: a systematic review and meta-analysis.
Across 162 studies with 675,361 patients, postoperative AKI after abdominal surgery occurred in 16% and showed a severity-dependent increase in mortality and length of stay. Importantly, meta-analysis of randomized trials indicated individualized blood pressure targets significantly reduce AKI risk (RR 0.67), whereas other single perioperative strategies showed no clear benefit.
Impact: This synthesis quantifies AKI burden and identifies a modifiable perioperative strategy—individualized BP targets—that reduces AKI, directly informing anesthetic and hemodynamic management.
Clinical Implications: Adopt individualized intraoperative BP targets tailored to patient baselines and comorbidities to reduce AKI risk; prioritize AKI risk stratification and bundles over single interventions like fluid type. Monitor AKI stage closely given graded mortality and LOS impact.
Key Findings
- Pooled postoperative AKI incidence after abdominal surgery was 16% (95% CI 14–17%).
- AKI severity showed a graded increase in short-term mortality (RR 6.46) and long-term mortality (RR 6.36).
- AKI prolonged hospital stay by 4.72 days on average, with stage-dependent increases (5.03, 11.16, 14.46 days for stages 1–3).
- Individualized blood pressure target management reduced AKI risk in RCTs (RR 0.67), while other single perioperative interventions showed no protective effect.
Methodological Strengths
- Comprehensive systematic review and meta-analysis across 162 studies with 675,361 patients
- PROSPERO-registered protocol with consensus AKI definitions (RIFLE/AKIN/KDIGO)
- Severity-stratified outcome analyses and inclusion of RCT meta-analysis on BP targets
Limitations
- Substantial heterogeneity across procedures and study designs
- Many included studies are observational with potential residual confounding
- Variability in perioperative practices and follow-up durations across studies
Future Directions: Conduct high-quality RCTs testing individualized BP targets in defined high-risk populations and evaluate AKI-prevention bundles integrating hemodynamics, nephrotoxin stewardship, and goal-directed care.
OBJECTIVE: To determine the incidence of acute kidney injury (AKI) following abdominal surgery, assess its outcome associations, and identify factors associated with postoperative AKI development. METHODS: We performed a systematic search of PubMed, Embase, and Cochrane Database of Systematic Reviews, from January 2004, to December 2024. We included studies reporting AKI based on consensus criteria (RIFLE, AKIN, or KDIGO) in adult abdominal surgery patients. RESULTS: A total of 162 studies (675361 patients) were included. The pooled AKI incidence was 16% (95% CI: 14-17%), with significant variation by surgical procedure. Meta-analysis showed AKI was significantly associated with increased short-term mortality (risk ratio [RR], 6.46; 95% CI: 4.63-9.00) and long-term mortality (RR, 6.36; 95% CI: 3.32-12.16). Mortality risk demonstrated stage-dependent increase, with RR of 2.74 (95%CI: 1.77-4.24), 8.01 (95%CI: 3.18-20.18), and 15.73 (95%CI: 5.52-44.81) for AKI stages 1, 2, and 3, respectively. AKI was associated with prolonged hospital stay (weighted mean difference 4.72 days; 95%CI: 3.43-6.02), also showeing stage-dependent increase of 5.03, 11.16, and 14.46 days for stages 1, 2, and 3, respectively. Twenty-five risk factors were associated with AKI. Meta-analysis of randomized controlled trials revealed that individualized blood pressure target management significantly reduced AKI incidence (RR, 0.67; 95% CI: 0.52-0.88). CONCLUSIONS: AKI remains a common and important complication after abdominal surgery, with severity showing a graded association with mortality and hospital stay. Individualized blood pressure management demonstrates promise in AKI prevention. REGISTRATION: PROSPERO CRD42022304083. The incidence of postoperative AKI after abdominal surgery is 16% (95% CI: 14–17%), varying by specific abdominal surgical procedure but not significantly different over time or by consensus definition.AKI severity shows a strong graded association with both short-term and long-term mortality, as well as prolonged hospital stays.Twenty-five factors were identified, providing valuable information for clinical risk assessment.Meta-analysis of randomized trials reveals that individualized blood pressure target management significantly reduces AKI incidence, while other single perioperative interventions (crystalloids versus colloids, restrictive versus liberal fluid management, cardiac output-guided therapy, hemodynamic monitoring) show no significant protective effects.
2. Oncologic Outcomes of Intraoperative Autologous Blood Transfusion for Major Oncologic Resection.
In a 444-patient cohort undergoing oncologic resection with IABT, early distant recurrence was uncommon (1.6% at 90 days; 7.9% at 1 year), and only one early metastasis could not be attributed to preoperative factors. In a liver transplant subgroup, IPTW-adjusted analyses showed no association between IABT and OS or RFS compared with allogeneic transfusion.
Impact: This challenges a long-standing contraindication by showing no signal of early metastasis or inferior survival with IABT, opening the door for safer blood management in cancer surgery.
Clinical Implications: Consider IABT as a blood conservation option during major oncologic resections, particularly when large-volume allogeneic transfusion is anticipated; decisions should be multidisciplinary and tailored to tumor type and institutional protocols.
Key Findings
- Among 444 IABT cases, distant recurrence occurred in 1.6% at 90 days and 7.9% at 1 year.
- Only 1 of 7 early distant recurrences was not attributable to preoperative factors.
- In malignancy liver transplant patients (n=406), IPTW-adjusted AHRs showed no association of IABT with OS (AHR 1.30; p=0.241) or RFS (AHR 1.15; p=0.498) versus allogeneic transfusion.
- Median autologous transfusion volume was 661 mL (IQR 337–1491 mL).
Methodological Strengths
- Relatively large single-institution cohort with prespecified early metastasis outcome
- Subgroup survival comparison using IPTW to mitigate confounding
- Detailed breakdown by cancer type, with transplant subgroup analyses
Limitations
- Single-center retrospective design with potential selection bias and residual confounding
- Early recurrence window (90 days/1 year) may miss later oncologic events
- IABT techniques and perioperative oncologic practices may limit generalizability
Future Directions: Prospective, multicenter studies comparing IABT versus allogeneic transfusion across tumor types, with standardized intraoperative salvage protocols and long-term oncologic follow-up.
BACKGROUND: Intraoperative autologous blood transfusion (IABT) is contraindicated during oncologic resection owing to concern for metastasis. However, there is a paucity of data to substantiate this claim, and the true risk of IABT in patients with cancer remains unknown. PATIENTS AND METHODS: We identified patients who underwent oncologic resection with IABT during 2010-2021 at our institution. The primary outcome was early metastasis. A subgroup analysis of patients who underwent liver transplants for malignancy was conducted using inverse probability of treatment weighting to compare survival between those who received autologous and allogeneic transfusions. RESULTS: Of 444 patients, the most common diagnoses were hepatocellular carcinoma (235, 52.9%), cholangiocarcinoma (68, 15.3%), and renal cell carcinoma (18, 4.1%). The median volume of autologous blood transfused was 661 mL (interquartile range (IQR) 337-1491 mL). A total of 7 patients (1.6%) experienced distant recurrence within 90 days, and 35 (7.9%) within 1 year. Of the seven patients with early distant recurrence, only one had metastasis not attributable to preoperative factors. In a subgroup analysis of patients undergoing liver transplant for malignancy, 299 patients who received IABT were compared with 107 patients who received allogeneic transfusion. After adjusting for cancer type, age, sex, estimated blood loss, model for end-stage liver disease (MELD) score, stage, and allograft type, IABT was not associated with overall survival (OS) [adjusted hazard ratio (AHR) 1.30 (95% confidence interval (CI) 0.82-2.03), p = 0.241] or recurrence-free survival (RFS) [AHR 1.15 (95% CI 0.77-1.73), p = 0.498]. CONCLUSIONS: IABT does not appear to be associated with early recurrence in patients undergoing oncologic resection. IABT should be investigated as a possible alternative to massive transfusion of allogeneic blood during oncologic resection.
3. Contemporary Trends in Pediatric Extubation Failure and Noninvasive Respiratory Support Use.
In 132,712 pediatric ICU encounters (2013–2022), use of postextubation noninvasive respiratory support nearly doubled while extubation failure declined modestly. Younger age, renal/respiratory/cardiac diagnoses, and ≥7 days of IMV increased EF risk; EF prolonged ventilation and LOS but did not increase risk-adjusted mortality.
Impact: This multicenter trend analysis informs extubation strategies by identifying who benefits from noninvasive support and where potential overuse may exist, guiding risk-stratified practice.
Clinical Implications: Implement risk-based postextubation support: consider proactive noninvasive support in infants and patients with renal, respiratory, or cardiac diagnoses or prolonged IMV; avoid routine use in low-risk patients and develop weaning protocols to minimize unnecessary support.
Key Findings
- Postextubation noninvasive respiratory support increased from 20.9% to 39.9% between 2013 and 2022 (RR 1.90).
- Extubation failure declined slightly (≤48 h: 8.9% to 8.1%; ≤7 d: 12.3% to 11.0%).
- Higher EF odds with younger age (<6 weeks OR 1.39; 6 weeks–12 months OR 1.24), renal (OR 1.25), respiratory (OR 1.15), and cardiac diagnoses (OR 1.10), and IMV ≥7 days (OR 1.26).
- EF associated with longer ventilation (11.6 vs 4.0 days), PICU LOS (18.8 vs 7.9 days), and hospital LOS (31.0 vs 15.0 days), without increased risk-adjusted mortality.
Methodological Strengths
- Very large multicenter dataset across 158 sites over a decade
- Standardized definitions enabling time-trend and risk factor analyses
- Adjusted regression models assessing EF predictors and outcomes
Limitations
- Retrospective cross-sectional design limits causal inference
- Potential unmeasured confounding and site-level practice variability
- Granularity of noninvasive support modalities and indications may be limited
Future Directions: Prospective trials to define criteria for prophylactic noninvasive support, and development/validation of pediatric EF risk scores to guide targeted application.
BACKGROUND: Prolonged invasive mechanical ventilation (IMV) is associated with morbidity and mortality in children. Timely extubation is essential and must balance the competing risks of extubation failure (EF) and prolonged use of noninvasive respiratory support after extubation. RESEARCH QUESTION: Did EF risk factors, EF rates, noninvasive respiratory support after extubation practices, and patient-centered outcomes changed between 2013 and 2022? STUDY DESIGN AND METHODS: Retrospective cross-sectional study of patients younger than 19 years receiving IMV for ≥ 24 hours and extubated between 2013 and 2022 from 158 North American sites in the Virtual Pediatric Intensive Care, LLC, quality improvement database. RESULTS: One hundred thirty-two thousand seven hundred twelve unique encounters were included. The overall EF rate was 8.5%. Postextubation noninvasive respiratory support use nearly doubled (2013 vs 2022: 20.9% vs 39.9%; relative risk [RR], 1.90 [95% CI, 1.83-1.98]; P < .01), whereas EF decreased slightly (≤ 48 hours: 8.9% vs 8.1%; RR, 0.92 [95% CI, 0.85-0.99]; P = .03; ≤ 7 days: 12.3% vs 11.0%; RR, 0.89 [95% CI, 0.83-0.95]; P < .01). Logistic regression identified increased odds of EF associated with younger age (< 6 weeks: OR, 1.39 [95% CI, 1.31-1.47]; P < .01; 6 weeks-12 months: OR, 1.24 [95% CI, 1.18-1.30]; P < .01), primary renal diagnosis (OR, 1.25 [95% CI, 1.04-1.48]; P = .01), respiratory diagnosis (OR, 1.15 [95% CI, 1.07-1.23]; P < .01), and cardiac diagnosis (OR, 1.10 [95% CI, 1.04-1.16]; P < .01), and ≥ 7 days of invasive ventilation before extubation (OR, 1.26 [95% CI, 1.21-1.32]; P < .01). EF rates were unchanged over time for patients with 0 or 1 risk factor. EF was associated with longer mechanical ventilation duration (11.6 days vs 4.0 days; P < .01), longer pediatric ICU length of stay (18.8 days vs 7.9 days; P < .01), and longer hospital length of stay (31.0 days vs 15.0 days; P < .01), but not with all-cause risk-adjusted mortality (8.5% vs 8.6%; RR, 1.16 [95% CI, 0.97-1.38]; P = .73). INTERPRETATION: Our results demonstrate that in the last decade, noninvasive respiratory support after extubation has nearly doubled, with an approximately 10% reintubation risk reduction. High-risk groups may benefit, but overuse may exist in low-risk groups with respect to EF. EF is associated with morbidity, but not increased mortality.