Objective

This study aims to investigate pulmonary protective and antiinflammatory effects of dexmedetomidine (DEX) in patients undergoing cardiac surgery with cardiopulmonary bypass (CPB) by meta-analysis.

Methods

Six databases were searched to collect trials on the pulmonary protective and anti-inflammatory effects of DEX in cardiac surgery with CPB. The search period was from the establishment of each database to August 1, 2024. Alveolar arterial oxygen partial pressure difference (AaDO2), Oxygenation index (OI), respiratory index (RI), IL-6, TNF-α, and CRP values were collected in CPB progress, end of operation, postoperative 6 h(POH6), and postoperative 24 h(POH24). The control group was treated with normal saline after anesthesia induction, while the experimental group with DEX.

Results

A total of 9 articles were included. In the overall analysis, AaDO2 (SMD=-1.03, 95%CI:-1.62 to -0.44) and RI (SMD=-1.03, 95%CI:-1.90 to -0.16) in the DEX group were significantly lower than those in the control group, whereas OI was significantly increased (SMD = 0.44, 95%CI: 0.29–0.60). For inflammatory markers, levels of IL-6 (SMD= -1.96, 95%CI: -2.31-1.62) and TNF-α (SMD= -1.81, 95%CI: -2.36-1.26) were significantly decreased in the DEX group. Subgroup analyses based on the course of surgery presented a significant reduction in AaDO2 at the end of operation. At the end of operation, OI was significantly increased, while IL-6 and TNF-α were significantly decreased at POH6 and POH12. At POH24, no significant difference was found in CRP between the two groups (P > 0.05).

Conclusion

DEX has pulmonary protective and anti-inflammatory effects in patients undergoing cardiac surgery with CPB.