Prevention of cardiac surgery-associated acute kidney injury: a systematic review and meta-analysis of non-pharmacological interventions.

BACKGROUND: Cardiac surgery-associated acute kidney injury (CSA-AKI) is frequent. While two network meta-analyses assessed the impact of pharmacological interventions to prevent CSA-AKI, none focused on non-pharmacological interventions. We aim to assess the effectiveness of non-pharmacological interventions to reduce the incidence of CSA-AKI. METHODS: We searched PubMed, Embase, Central and clinical trial registries from January 1, 2004 (first consensus definition of AKI) to July 1, 2023. Additionally, we conducted manual screening of abstracts of major anesthesia and intensive care conferences over the last 5 years and reference lists of relevant studies. We selected all randomized controlled trials (RCTs) assessing a non-pharmacological intervention to reduce the incidence of CSA-AKI, without language restriction. We excluded RCTs of heart transplantation or involving a pediatric population. The primary outcome variable was CSA-AKI. Two reviewers independently identified trials, extracted data and assessed risk of bias. Random-effects meta-analyses were conducted to calculate risk ratios (RRs) with 95% confidence intervals (CIs). We used the Grading of Recommendations Assessment, Development, and Evaluation to assess the quality of evidence. RESULTS: We included 86 trials (25,855 patients) evaluating 10 non-pharmacological interventions to reduce the incidence of CSA-AKI. No intervention had high-quality evidence to reduce CSA-AKI. Two interventions were associated with a significant reduction in CSA-AKI incidence, with moderate quality of evidence: goal-directed perfusion (RR, 0.55 [95% CI 0.40-0.76], I2 = 0%; Phet = 0.44) and remote ischemic preconditioning (RR, 0.86 [0.78-0.95]; I2 = 23%; Phet = 0.07). Pulsatile flow during cardiopulmonary bypass was associated with a significant reduction in CSA-AKI incidence but with very low quality of evidence (RR = 0.69 [0.48; 0.99]; I2 = 53%; Phet < 0.01). We found high quality of evidence for lack of effect of restrictive transfusion strategy (RR, 1.02 [95% CI 0.92; 1.12; Phet = 0.67; I2 = 3%) and tight glycemic control (RR, 0.86 [95% CI 0.55; 1.35]; Phet = 0.25; I2 = 26%). CONCLUSIONS: Two non-pharmacological interventions are likely to reduce CSA-AKI incidence, with moderate quality of evidence: goal-directed perfusion and remote ischemic preconditioning.

Heterogeneity in the definition of delirium in ICUs and association with the intervention effect in randomized controlled trials: a meta-epidemiological study.

PURPOSE: To evaluate the heterogeneity in the definition of delirium in randomized controlled trials (RCTs) included in meta-analyses of delirium in intensive care units (ICUs) and to explore whether intervention effect depends on the definition used. METHODS: We searched PubMed for meta-analyses including RCTs evaluating prevention or treatment strategies of delirium in ICU. The definition of delirium was collected from RCTs and classified as validated (DSM criteria, CAM-ICU, ICDSC, NEECHAM, DRS-R98) or non-validated (non-validated scales, set of symptoms, physician appreciation or not reported). We conducted a meta-epidemiological analysis to compare intervention effects between trials using or not a validated definition by a two-step method as primary analysis and a multilevel model as secondary analysis. A ratio of odds ratios (ROR) < 1 indicated larger intervention effects in trials using a non-validated definition. RESULTS: Of 149 RCTs (41 meta-analyses), 109 (73.1%) used a validated definition and 40 (26.8%) did not (including 31 [20.8%] not reporting the definition). The primary analysis of 7 meta-analyses (30 RCTs) found no significant difference in intervention effects between trials using a validated definition and the others (ROR = 0.54, 95% CI 0.27-1.08), whereas the secondary multilevel analysis including 12 meta-analyses (67 RCTs) found significantly larger effects for trials using a non-validated versus a validated definition (ROR = 0.36, 95% CI 0.21-0.62). CONCLUSION: The definition of delirium was heterogeneous across RCTs, with one-fifth not reporting how they evaluated delirium. We did not find a significant association with intervention effect in the primary analysis. The secondary analysis including more studies revealed significantly larger intervention effects in trials using a non-validated versus a validated definition.