Variants for dosing of rocuronium taken into obesity during general anesthesia in gynecological laparoscopic surgery

The objective was to identify the optimal method of dosing the muscle relaxant rocuronium during gynecological laparoscopic surgery in obese patients.

Materials and methods. The study included 36 women with obesity II–III degree, which performed elective gynecological laparoscopic surgery. They were divided into 3 groups. In group 1, rocuronium were dosed at the rate of 0.6 mg/kg of ideal body weight calculated by the Lorentz formula. In group 2, rocuronium were dosed at the rate of 0.6 mg/kg of actual body weight. In group 3, rocuronium were dosed at the rate of 22.5 mg/m2 of body surface area. The comparison group (group 0) included 20 patients with body mass index equal to 18.5–25 kg/m2.

Results. The shortest time for the onset of deep neuromuscular block was noted in groups 2 and 3, and the longest, comparable to the indicator in group 0, was in group 1 (p < 0.05). The time from rocuronium administration to the onset of restoration of neuromuscular conduction was the shortest in group 1: 22 [20; 25] minutes, and the longest in group 2: 40 [35; 45] min. There was no statistically significant difference in the dosing of rocuronium in obese patients at body surface area in group 3 compared with dosing for actual weight in group 0: 27 [22; 29] and 27 [25; 33] min, respectively. The recovery time of neuromuscular conduction from TOF = 1 to TOF = 25% was the shortest in group 1 (23 [18; 24] min) and was significantly different from the value in groups 2 and 3, as well as in patients of group 0. In groups 0, 2, 3, values of this indicator were identical. The recovery index did not differ significantly in all four groups.

Conclusion. Dosing rocuronium in obese patients based on body surface area has an advantage for comparison over dosing based on both actual and ideal body weight, resulting in greater predictability of neuromuscular block dynamics.

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