Daily Anesthesiology Research Analysis
Three impactful anesthesiology studies stand out today: a large multicenter pediatric study (J-PEDIA) defining airway adverse event risks and protective practices; a randomized trial showing that modestly higher cardiopulmonary bypass flow improves renal filtration and reduces tubular injury markers; and a 100k-patient cohort linking low-dose intraoperative ketamine with reduced postoperative delirium. Together, they inform safer airway strategies, kidney-protective perfusion, and neurocognitive
Summary
Three impactful anesthesiology studies stand out today: a large multicenter pediatric study (J-PEDIA) defining airway adverse event risks and protective practices; a randomized trial showing that modestly higher cardiopulmonary bypass flow improves renal filtration and reduces tubular injury markers; and a 100k-patient cohort linking low-dose intraoperative ketamine with reduced postoperative delirium. Together, they inform safer airway strategies, kidney-protective perfusion, and neurocognitive outcomes.
Research Themes
- Pediatric airway safety and risk stratification
- Renal protection strategies during cardiopulmonary bypass
- Neurocognitive outcomes and intraoperative ketamine dosing
Selected Articles
1. Adverse Events Associated with Airway Management in Pediatric Anesthesia: A Prospective, Multicenter, Observational Japan Pediatric Difficult Airway in Anesthesia (J-PEDIA) Study.
In 17,007 pediatric airway-securing procedures, adverse events occurred in 2.0% and desaturation in 2.3%, with markedly higher desaturation in neonates (21.4%) and infants (9.1%). Risk factors included younger age, airway management in radiation rooms, airway sensitivity, craniocervical surgery, and difficult airway features; first-attempt supraglottic airway use and muscle relaxants were protective.
Impact: This is a large, prospective, multicenter study that quantifies pediatric airway risks and identifies modifiable practice factors, directly informing perioperative safety strategies.
Clinical Implications: Prioritize risk stratification in neonates/infants, consider first-attempt supraglottic airway devices and appropriate neuromuscular blockade, and anticipate higher risk in radiation rooms and craniocervical surgeries to reduce airway events and desaturation.
Key Findings
- Any adverse event occurred in 2.0% and desaturation (≥10% SpO2 drop) in 2.3% of 17,007 pediatric airway procedures.
- Desaturation was highest in neonates (21.4%) and infants (9.1%).
- Risk factors: younger age (aOR 0.92 per year), radiation diagnostic/therapy rooms (aOR 5.7), airway sensitivity (aOR 1.46), craniocervical surgery (aOR 1.41), difficult airway features (aOR 1.74 for one feature; 2.82 for ≥2).
- Protective factors: first-attempt supraglottic airway device use (aOR 0.42) and muscle relaxant administration (aOR 0.62).
Methodological Strengths
- Prospective, multicenter design with standardized data capture across 10 tertiary hospitals and ≥95% case inclusion.
- Multilevel regression modeling to identify independent risk and protective factors.
Limitations
- Observational design limits causal inference and residual confounding is possible.
- Generalizability may be limited to tertiary centers in Japan; outcomes limited to intraoperative period.
Future Directions: Validate risk models internationally, assess impact of implementing first-attempt supraglottic airway and neuromuscular blockade protocols on hard outcomes, and explore tailored strategies for neonates and radiation suites.
BACKGROUND: The incidence of adverse events and desaturation during airway-securing procedures (a sequence from preoxygenation to completion of tracheal intubation or supraglottic airway placement) under general anesthesia in children remains underexplored. Thus, this study investigated the incidence of adverse and desaturation events and associated risk factors. METHODS: This was a prospective, multicenter, observational study conducted between June 2022 and January 2024 in 10 tertiary care (6 pediatric and 4 university [mixed adult-pediatric]) hospitals in Japan. A standar
2. Effects of Increased Cardiopulmonary Bypass Pump Flow on Renal Filtration, Perfusion, Oxygenation, and Tubular Injury in Cardiac Surgical Patients: A Randomized Controlled Trial.
In a randomized trial (n=36), increasing CPB flow by ~20% improved glomerular filtration rate and reduced urinary N-acetyl-β-D-glucosaminidase release, with higher systemic oxygen delivery and lower norepinephrine requirements. Renal blood flow and oxygen extraction did not differ, and no perfusion-related adverse events occurred.
Impact: This trial provides mechanistic evidence that modestly higher CPB flow can enhance renal filtration and attenuate tubular injury, informing perfusion targets during cardiac surgery.
Clinical Implications: Consider a modest increase in CPB flow to improve renal filtration and reduce tubular injury markers, while monitoring hemodynamics; confirm in larger trials with clinical AKI outcomes before changing guidelines.
Key Findings
- High-flow CPB increased systemic oxygen delivery more than standard flow (ΔDO2: 100 vs 31 mL·min−1·m−2; P<0.001).
- Mean arterial pressure targets were maintained with lower norepinephrine doses in the high-flow group (0.03 vs 0.10 µg·kg−1·min−1; P=0.048).
- GFR increased with high-flow CPB (+6.4 vs −2.3 mL·min−1·1.73 m−2; P=0.044).
- Urinary NAG peak was lower with high-flow (1.42 vs 3.74 units/µmol creatinine; P=0.049); no perfusion-related adverse events.
Methodological Strengths
- Randomized, parallel-arm design with prespecified physiologic endpoints.
- Direct measurements of GFR (iohexol clearance) and renal blood flow (PAH clearance with renal vein catheter).
Limitations
- Single-center, small sample size, and nonblinded design.
- Surrogate outcomes; not powered to detect differences in clinical AKI or long-term renal outcomes.
Future Directions: Multicenter RCTs powered for AKI and patient-centered outcomes; refine flow targets by patient risk and integrate with perfusion pressure strategies.
BACKGROUND: Cardiac surgery with cardiopulmonary bypass (CPB) is associated with impaired renal oxygenation and acute kidney injury. The authors investigated whether an amount higher than their standard blood flow during CPB could improve renal blood flow, the oxygen demand-supply relationship, and function and attenuate tubular injury. METHODS: After ethical approval and informed consent, 36 adult patients undergoing cardiac surgery received either high flow (2.9 l · min -1 · m -2 , n = 19) or standard flow (2.4 l · min -1 · m -2 , n = 17) during CPB in this randomized, nonblinded, parallell-arm study. Systemic hemodynamics and renal variables were measured before and during CPB. Glomerular filtration rate was measured by infusion clearance of iohexol and renal blood flow by infusion clearance of para-aminohippuric acid, corrected for renal extraction of para-aminohippuric acid, using a renal vein catheter. Renal oxygen demand-supply relationship was estimated from renal oxygen extraction and tubular injury assessed by urinary N -acetyl-β- d -glucosaminidase. RESULTS: During CPB, high flow led to a larger increase in systemic oxygen delivery (100 [95% CI, 60 to 141] vs. 31 [1.9 to 65] ml · min -1 · m -2 ]; between-group P < 0.001; effect size Cohen's dz , 0.59) and target mean arterial pressure was maintained at a lower norepinephrine dose (0.03 [-0.01 to 0.06] µg · kg -1 · min -1 ] vs. 0.10 [0.02 to 0.19] µg · kg -1 · min -1 ; P = 0.048; Cohen's dz , 0.62) compared with standard flow. There were no differences in renal blood flow or oxygen extraction between groups. Glomerular filtration rate increased during high-flow CPB (6.4 [1.9 to 10.9] ml · min -1 · 1.73 m -2 ), but not in the standard-flow group (-2.3 [-10.9 to 6.2] ml · min -1 · 1.73 m -2 ; between-group P = 0.044; Cohen's dz , 0.66). The peak urinary excretion of N -acetyl-β- d -glucosaminidase was 1.42 (0.87 to 3.6) versus 3.74 (1.5 to 7.7) units/µmol creatinine in the high-flow and standard-flow groups, respectively ( P = 0.049). No perfusion-related adverse events were seen in either group. CONCLUSIONS: A 20% higher-than-standard CPB flow during cardiac surgery improved renal function, whereas no change in renal blood flow or oxygen demand-supply relationship could be detected. Higher CPB flow was associated with a less pronounced tubular injury marker release compared with standard flow.
3. Dose-dependent relationship between intra-operative ketamine administration and postoperative delirium: a retrospective cohort study.
Among 106,982 adults under general anesthesia, postoperative delirium occurred in 2.7%. Low-dose intraoperative ketamine (≤0.35 mg/kg; optimal ~0.25–0.34 mg/kg) was associated with a lower delirium risk, whereas higher doses showed no risk reduction.
Impact: This very large cohort provides dose–response evidence to guide intraoperative ketamine dosing with a neurocognitive safety lens, addressing inconsistent trial findings.
Clinical Implications: When using ketamine as an adjunct, consider low dosing (≈0.25–0.34 mg/kg cumulative intraoperative) to potentially reduce postoperative delirium, while avoiding higher doses in patients at delirium risk; prospective trials are warranted.
Key Findings
- Postoperative delirium incidence was 2.7% across 106,982 general anesthesia cases.
- 11.4% received intraoperative ketamine; median dose 0.35 mg/kg.
- Low-dose ketamine (≤0.35 mg/kg; optimal ~0.25–0.34 mg/kg) was associated with reduced delirium risk; higher doses showed no benefit.
Methodological Strengths
- Extremely large, contemporary cohort with dose-stratified analysis.
- Assessment of delirium using multiple data sources over the first postoperative week.
Limitations
- Retrospective design with potential confounding by indication and dose selection bias.
- Delirium ascertainment may vary across clinicians and documentation; non-cardiac surgical population only.
Future Directions: Randomized trials testing low-dose ketamine protocols focused on delirium outcomes; refine dosing by patient frailty/cognitive risk and analgesic requirements.
INTRODUCTION: Ketamine is used frequently as an adjunct for general anaesthesia, exerting analgesic and opioid-sparing properties at lower doses and psychotomimetic effects at higher doses. All dose ranges may have effects on the incidence of postoperative delirium, but clinical trials have been equivocal. We hypothesised that intra-operative low-dose ketamine is associated with a lower risk of postoperative delirium. METHODS: A total of 106,982 adult patients undergoing general anaesthesia for non-cardiac, non-neurosurgical and non-transplant procedures between 2008 and 2024 were included. Primary exposure was the intra-operative cumulative ketamine dose (mg.kg RESULTS: Postoperative delirium occurred in 2837 (2.7%) patients. In total, 12,199 (11.4%) patients received ketamine, with a median (IQR [range]) intra-operative dose of 0.35 (0.25-0.52 [0.01-3.86]) mg.kg DISCUSSION: Intra-operative low-dose ketamine was associated with a lower risk of postoperative delirium, while high doses did not influence the risk. Ketamine is a medicine often used during surgery to help with pain. Small amounts can help reduce pain and the need for strong painkillers. Large amounts can cause strange thoughts or feelings. Doctors aren't sure if ketamine changes the chance of patients feeling confused after surgery, which is called delirium. This study looked at whether giving a low dose of ketamine during surgery makes delirium less likely. The study looked at 106,982 adults who had surgery (not heart, brain or transplant surgery) between 2008 and 2024. It compared patients who got high or low doses of ketamine during surgery. The researchers checked if the patients had delirium in the week after surgery using hospital records, doctor notes and special tests. Out of all the patients, 2.7% had delirium after surgery. About 11% of patients received ketamine. The middle dose given was about 0.35 mg for each kilogram of body weight. Patients who got a low dose (0.35 mg per kg or less) had a lower chance of delirium. Patients who got a higher dose (more than 0.35 mg per kg) had no change in their chance of getting delirium. The safest dose seemed to be between 0.25 mg per kg and 0.34 mg per kg. Giving a small amount of ketamine during surgery may help lower the chance of confusion afterwards. Higher doses didn't make a difference.