# Perioperative dexmedetomidine and renal outcomes in adult cardiac surgery: an updated systematic review and meta-analysis

## TL;DR

Dexmedetomidine reduces acute kidney injury and improves recovery after cardiac surgery, but optimal dosing needs more study.

## Contribution

This meta-analysis identifies effective dosing ranges of dexmedetomidine for renal protection in cardiac surgery patients.

## Key findings

- DEX reduced AKI incidence with a relative risk of 0.58 compared to control groups.
- DEX shortened ICU and hospital stays, but had no effect on mortality or intraoperative times.
- Optimal DEX dosing (0.6–0.1 μg/kg/h) showed significant benefits, while lower doses did not.

## Abstract

Acute kidney injury (AKI) is a common complication following cardiac surgery, associated with increased morbidity and mortality. Dexmedetomidine (DEX), a highly selective α-2 adrenoceptor agonist, has shown potential renal protective effects, but evidence remains inconsistent. This study aims to evaluate the efficacy of DEX in preventing AKI and improving renal outcomes in cardiac surgery patients through a systematic review and meta-analysis of randomized controlled trials (RCTs).

A comprehensive search of PubMed, Cochrane Library, Embase, and Web of Science was conducted until April 2025. PICOS criteria were applied to select studies comparing DEX with placebo/normal saline in cardiac surgery patients. Primary outcomes included AKI incidence; secondary outcomes encompassed intraoperative parameters, postoperative recovery, and complications.

Bibliometric analysis highlighted China and the USA as leading contributors, with emerging trends in pediatric and mechanistic research. Among 16 RCTs (n = 2,882), DEX significantly reduced AKI incidence [RR 0.58; 95% CI 0.37 to 0.91; I2 = 74%, p = 0.02], particularly at 0.6–0.1 μg/kg/h doses [RR 0.43; 95% CI 0.26 to 0.71; I2 = 0%, p = 0.001]. Subgroup analysis revealed 0.4 μg/kg/h doses failed to yield a statistically significant benefit [RR 0.65; 95% CI 0.36 to 1.17; I2 = 84%; p = 0.15]. DEX also shortened ICU stay [MD −1.23; 95% CI −2.17 to −0.30; I2 = 93%; p = 0.01], mechanical ventilation duration [MD −1.24; 95% CI −2.15 to −0.33; I2 = 97%; p = 0.008], and hospital stays [MD −0.33; 95% CI −0.54 to −0.13; I2 = 86%; p = 0.01]. However, it did not affect mortality or intraoperative times.

DEX demonstrates significant renal protection and improves postoperative recovery in cardiac surgery patients, though optimal dosing requires further investigation. These findings support its integration into perioperative protocols but underscore the need for standardized dosing regimens.

Identifier, INPLASY2025120019.

DEX, dexmedetomidine; NS, not significant; CPB, cardiopulmonary bypass; ICU, intensive care unit; DM, diabetes mellitus; HTN: hypertension.Study on dexmedetomidine's impact on acute kidney injury (AKI) and renal outcomes after cardiac surgery. Criteria: databases searched up to April 2025; 104 studies analyzed, 16 for meta-analysis, with 2,882 participants. Outcomes include AKI incidence and various surgical and postoperative factors. Results show 12.6% AKI incidence in DEX group versus 16.12% in control, with significant findings for ICU and hospital stay improvements with DEX.

DEX, dexmedetomidine; NS, not significant; CPB, cardiopulmonary bypass; ICU, intensive care unit; DM, diabetes mellitus; HTN: hypertension.