Daily Anesthesiology Research Analysis
Analyzed 90 papers and selected 3 impactful papers.
Summary
Analyzed 90 papers and selected 3 impactful articles.
Selected Articles
1. Balanced Fluid or 0.9% Saline in Children Treated for Septic Shock.
In a multicenter pragmatic RCT of 8482 analyzed children with suspected septic shock, balanced crystalloids did not reduce 30-day major adverse kidney events compared with 0.9% saline. Electrolyte abnormalities (hyperchloremia, hypernatremia) were less frequent with balanced fluids, but clinical outcomes and hospital-free days were similar.
Impact: This definitive trial informs fluid selection in pediatric septic shock, showing no superiority of balanced crystalloids on hard renal outcomes despite improved electrolyte profiles.
Clinical Implications: Protocols may reasonably prioritize either balanced fluids or saline based on availability, cost, and electrolyte considerations, with attention to chloride and sodium levels. Routine outcome benefits from switching to balanced solutions are unlikely.
Key Findings
- No difference in 30-day major adverse kidney events: 3.4% (balanced) vs 3.0% (saline); RR 1.10 (95% CI 0.88–1.40), P=0.85.
- Hospital-free days were identical (median 23 days; IQR 19–25) in both groups.
- Electrolyte disturbances were lower with balanced fluids: hyperchloremia 31.4% vs 49.0%; hypernatremia 1.8% vs 3.1%; hyperlactatemia slightly higher 19.8% vs 16.7%.
Methodological Strengths
- Large, multicenter, pragmatic randomized trial across 47 emergency departments with preregistered protocol
- Clinically meaningful composite primary endpoint with blinded adjudication of laboratory outcomes likely standardized across sites
Limitations
- Open-label design may introduce performance bias
- Low event rates limit power for subgroup effects and rare adverse events; fluid exposure limited to 48 hours
Future Directions: Identify subgroups (e.g., high AKI risk, severe hyperchloremia) who may benefit from specific fluids; evaluate long-term neurodevelopmental and renal outcomes and cost-effectiveness.
BACKGROUND: Whether treatment with balanced crystalloid fluid leads to better outcomes than 0.9% saline in children treated for septic shock is debated. METHODS: In this pragmatic clinical trial conducted at 47 emergency departments in five countries, patients (2 months to <18 years of age) with suspected septic shock and abnormal perfusion were randomly assigned to receive fluid resuscitation with either balanced fluid or 0.9% saline for up to 48 hours. The primary outcome was a major adverse kidney event (a composite of death, new renal-replacement therapy, or persistent kidney dysfunction) at 30 days after enrollment or hospital discharge, whichever occurred first. RESULTS: Of 9041 enrolled patients, 277 (6.1%) in the balanced-fluid group and 282 (6.2%) in the 0.9%-saline group withdrew from the trial, leaving 4235 and 4247 patients, respectively, for analysis. A primary-outcome event occurred in 137 patients (3.4%) in the balanced-fluid group and in 124 (3.0%) in the 0.9%-saline group (difference, 0.4 percentage points; 95% confidence interval [CI], -0.5 to 1.3; risk ratio, 1.10; 95% CI, 0.88 to 1.40; P = 0.85). The median number of hospital-free days during 28 days after enrollment was 23 (interquartile range, 19 to 25) in both groups. Hyperchloremia occurred in 868 patients (31.4%) in the balanced-fluid group and in 1383 (49.0%) in the 0.9%-saline group; hypernatremia in 52 (1.8%) and 89 (3.1%), respectively; and hyperlactatemia in 260 (19.8%) and 228 (16.7%). No differences in other safety outcomes or adverse events were seen. CONCLUSIONS: Among children treated for septic shock, no significant difference was seen in the incidence of death, new renal-replacement therapy, or persistent kidney dysfunction when fluid resuscitation was administered with balanced fluid as compared with 0.9% saline. (Funded by Eunice Kennedy Shriver National Institute of Child Health and Human Development and others; PRoMPT BOLUS ClinicalTrials.gov number, NCT04102371.).
2. Remimazolam-induced dysfunction of thalamic reticular nucleus impairs auditory gating during postanaesthetic recovery in mice.
Using electrophysiology and optogenetics in mice, remimazolam suppressed neural responses during anesthesia but produced rebound hyper-responsiveness with impaired auditory gating during recovery. Dysfunction of GABAergic neurons in the thalamic reticular nucleus reduced inhibition of bottom-up inputs, providing a mechanistic basis for sensory hypersensitivity and agitation after benzodiazepine anesthesia.
Impact: Reveals a specific thalamic circuit mechanism for postanesthetic sensory dysregulation, suggesting testable strategies (e.g., noise mitigation, pharmacologic modulation) to reduce emergence agitation.
Clinical Implications: Consider minimizing perioperative benzodiazepines in patients prone to emergence agitation, use environmental noise control, and evaluate reversal (e.g., flumazenil) or alternative sedatives to mitigate sensory hypersensitivity.
Key Findings
- Auditory gating deficits during recovery with increased T2/T1 ratios across posterior parietal cortex, dorsal hippocampus, and mediodorsal thalamus (all P<0.001).
- Top-down and bottom-up inputs were blocked during anesthesia; during recovery, top-down normalized while bottom-up exceeded baseline, aligning with gating failure.
- GABAergic thalamic reticular nucleus neurons showed reduced sustained responses during recovery (proportion 63.0% vs 29.3%; max firing 28.9 vs 17.4 Hz), reducing inhibition of sensory inputs.
Methodological Strengths
- Multi-region recordings with Neuropixels and local field potentials enabling circuit-level resolution
- Causal testing with optogenetics to dissect top-down versus bottom-up contributions
Limitations
- Preclinical mouse model limits direct generalizability to humans
- Focused on remimazolam; applicability to other benzodiazepines requires confirmation
Future Directions: Validate auditory gating changes and TRN signatures in humans under benzodiazepine anesthesia; test mitigation strategies (e.g., flumazenil, sensory attenuation) in clinical trials.
BACKGROUND: Perioperative benzodiazepines increase the risk of sensory hypersensitivity and agitation during recovery, but the neural mechanisms remain unclear. Auditory gating filters redundant information to prevent network overload. We hypothesise that benzodiazepines impair auditory gating during recovery, leading to heightened auditory responsiveness. METHODS: Simultaneous electroencephalography, electromyography, and behavioural analyses assessed the effects of remimazolam, a novel benzodiazepine, on arousal states. Multi-region microelectrodes and Neuropixels probes recorded cortical and subcortical local field potentials and single-unit activity. Optogenetics was applied to test the impact of remimazolam on auditory gating. RESULTS: Both spontaneous and paired-tone evoked neuronal activity were suppressed during anaesthesia and sedation, followed by rebound enhancement and auditory gating deficits during recovery (T2/T1 ratio in posterior parietal cortex: baseline 0.38 [0.01] vs recovery 0.82 [0.02], P<0.001; dorsal hippocampus: 0.34 [0.01] vs 1.10 [0.03], P<0.001; and mediodorsal thalamic nucleus: 0.48 [0.01] vs 1.12 [0.02], P<0.001]). Optogenetic manipulations of the prefrontal cortex and brainstem auditory nuclei revealed that both top-down and bottom-up inputs were blocked during anaesthesia. During recovery, top-down inputs normalised, whereas bottom-up inputs exceeded baseline, along with gating deficits. A subset of gamma-aminobutyric acid (GABA)ergic neurones in thalamic reticular nucleus exhibited sustained responses to paired tones. During recovery, both their proportion (63.0% vs 29.3%) and firing strength (maximum firing rate: 28.9 [3.9] vs 17.4 [3.0], P<0.001) were diminished, resulting in insufficient inhibition of bottom-up inputs and exaggerated responses to external stimuli. CONCLUSIONS: Our findings elucidate the dynamic changes in sensory processing and the underlying mechanisms during benzodiazepine-induced anaesthesia and recovery, providing valuable insights for optimising clinical anaesthesia management and postoperative recovery strategies.
3. Development and Validation of a Cystatin C-based Staging of AKI in Critically Ill Patients.
A mortality-aligned cystatin C-based AKI staging system was derived from 9424 critically ill patients and validated externally, defining thresholds that identified 11% more AKI and 10% more stage 3 than creatinine-based KDIGO. Reclassification to AKI by cystatin C was associated with higher mortality, supporting its prognostic value.
Impact: Provides clinically actionable cystatin C thresholds that better stratify AKI risk than creatinine in ICU settings, enabling earlier detection and risk-aligned management.
Clinical Implications: Incorporating cystatin C into perioperative/ICU AKI surveillance may improve early identification and prognostication, informing nephrotoxin stewardship, fluid management, and RRT planning.
Key Findings
- Defined cystatin C thresholds: Stage 1 (1.40–1.59× baseline within 7 days or ≥0.44 mg/L in 48 h), Stage 2 (1.60–2.09×), Stage 3 (>2.10× or ≥2.80 mg/L).
- Cystatin C staging identified 11% more AKI and 10% more stage 3 than creatinine-based KDIGO.
- Reclassification to AKI by cystatin C (from no AKI) carried higher mortality risk (HR 1.36), validated across cohorts and infection strata.
Methodological Strengths
- Large multicenter cohort with mortality-aligned threshold derivation and external validation
- Adjusted survival analyses with long-term follow-up increasing robustness of prognostic performance
Limitations
- Observational design cannot establish causality or clinical impact of cystatin C-guided interventions
- Abstract does not report validation cohort size; assay standardization and baseline estimation methods may influence thresholds
Future Directions: Prospective trials to test cystatin C-guided AKI prevention/treatment pathways and cost-effectiveness; harmonize assays and integrate into perioperative risk tools.
INTRODUCTION: Acute kidney injury (AKI) criteria and staging are based on serum creatinine and urine output, but serum cystatin C performs better at estimating glomerular filtration rate (GFR) in critically ill patients. Accordingly, a cystatin C-based AKI staging system was developed and its performance studied in critically ill patients. METHODS: AKI stages according to Kidney Disease: Improving Global Outcomes (KDIGO) creatinine criteria were converted to corresponding cystatin C-based stages using 14-day mortality in 9424 critically ill patients from 3 Swedish hospitals followed for 5.6 years (median interquartile range: 2.8-7.2). Model performance was evaluated using Cox regression on long-term mortality adjusted for age, gender, comorbidities, and unit type. An independent cohort ( RESULTS: KDIGO stages corresponded to the following: Stage 1: increase in cystatin C 1.40 to 1.59 times baseline within 7 days or ≥ 0.44 mg/l within 48 hours; Stage 2: 1.60 to 2.09 times baseline; and Stage 3: above 2.10 times baseline or ≥ 2.80 mg/l. Cystatin C-based versus creatinine-based staging identified 11% more AKI and 10% more Stage 3. Patients reclassified to AKI by cystatin C from no AKI had a higher risk of death of 1.36 (1.24-1.49), whereas those reclassified vice versa had a lower risk 0.71 (0.56-0.91). These findings were consistent irrespective of infection status for 30-day mortality. In the validation cohort, reclassification to a higher stage by cystatin C was an independent predictor of increased risk of death. CONCLUSION: In critically ill patients, cystatin C-based staging identified more AKI than KDIGO criteria, and these patients had increased short- and long-term mortality.