The effect of remimazolam combined with low-dose propofol on diaphragmatic function in patients undergoing...

Propofol frequently induces respiratory depression in hysteroscopy, with diaphragmatic dysfunction being a potential contributing mechanism. This study utilized ultrasound technology to investigate whether remimazolam combined with low-dose propofol can attenuate diaphragmatic dysfunction compared to propofol alone in patients undergoing hysteroscopic surgery.

Patients undergoing hysteroscopic surgery were randomized 1:1 to either remimazolam 0.2 mg/kg with propofol 1 mg/kg (RP group) or propofol 2.5 mg/kg alone (P group) for induction. Both groups received sufentanil pretreatment and propofol-remifentanil maintenance. Hemodynamic parameters (mean arterial pressure, MAP; heart rate, HR), respiratory parameters (respiratory rate, RR; pulse oxygen saturation, SpO₂), and diaphragmatic parameters (diaphragmatic excursion, DE; diaphragm thickening fraction, DTF) were compared at specified timepoints: T0 (Baseline): 5 min after entering the operating room; T1: 6 min after administration of the sedative; T2: 5 min after removal of the laryngeal mask airway (LMA); T3: 5 min before discharge from the post-anesthesia care unit (PACU). Adverse reactions, including respiratory/diaphragmatic depression, injection pain, hypotension, and hiccups, were also compared.

Eighty patients completed the final analysis. The RP group showed significantly higher DTF values compared to the P group at T1, T2, and T3 (P = 0.02; P < 0.001; P = 0.030). Additionally, the RP group had a significantly lower incidence of diaphragm dysfunction (P = 0.007), injection pain (P = 0.043), and hypotension (P = 0.048) compared to the P group. Notably, the RP group had a significantly higher rate of spontaneous (assisted) breathing compared to the P group (P = 0.011). However, the incidence of hiccups increased markedly in the RP group compared to the P group (P = 0.044). There were no statistically significant differences between the two groups in terms of respiratory depression, delayed awakening, or dizziness (P = 0.235; P = 1.000; P = 0.136).

Compared to propofol, the combination of remimazolam and low-dose propofol can significantly alleviate diaphragmatic dysafunction in patients undergoing hysteroscopic surgery, while preserving spontaneous breathing more effectively. Optimized therapeutic regimens may prevent respiratory complications and accelerate recovery.

Chinese Clinical Trial Registry, identifier: ChiCTR2500102592, Date: 16/5/2025.