[Effects of residual paralysis after a single intubating dose of rocuronium on postoperative pulmonary function of patients undergoing laparoscopic gynecological surgeries].

OBJECTIVE

To evaluate the residual paralysis after a single intubating dose of rocuronium and its effect of residual paralysis after a single dose of rocuronium on the postoperative pulmonary function of patients undergoing laparoscopic gynecological surgeries.

METHODS

Sixty American Society of Anesthesiologists (ASA) I - II patients undergoing laparoscopic gynecological surgeries were randomly divided into rocuronium (R) group (n = 30) and rocuronium + neostigmine (R + N) group (n = 30).All patients received midazolam (0.02 mg/kg), fentanyl (1 microg/kg), propofol(1.5-2 mg/kg), and rocuronium (0.6 mg/kg) to facilitate tracheal intubation and no more relaxant thereafter. Anesthesia was maintained with isoflurane and nitrous oxide in oxygen (N(2)O:O(2) = 1:1). At the end of the procedure, neuromuscular blockade was not reversed in R group, while antagonism was accomplished with neostigmine (0.04 mg/kg) and atropine (0.02 mg/kg) in R + N group. Immediately after tracheal extubation and on arrival in the PACU, the train-of-four (TOF) ratio at the adductor pollicis of all patients were measured using acceleromyography. Forced vital capacity (FVC), forced expiratory volume in one second (FEV(1)), and peak expiratory flow rate (PEFR) of all patients were measured using spirometry before surgery, after administration of midazolam and fentanyl, immediately after tracheal extubation, on arrival in the PACU, and after the TOF ratio recovered to 1.0. The TOF ratio and pulmonary function between two groups were compared.

RESULTS

Immediately after tracheal extubation and on arrival in the PACU, the mean TOF ratio in R group was significantly lower than that in R + N group (P < 0.05). The mean time to achieve TOF ratio of 0.9 and 1.0 in R group was significantly longer than in R + N group (P < 0.05). Immediately after tracheal extubation and on arrival in the PACU, FVC, FEV(1), and PEFR were significantly lower in R group than in R + N group (P < 0.05). FVC, FEV(1), and PEFR after administration of midazolam and fentanyl and after TOF ratio recovered to 1.0 were significantly lower than the baseline values in all patients (P < 0.01).

CONCLUSIONS

After a single intubating dose of rocuronium, residual paralysis exists in the majority of patients undergoing laparoscopic gynecological surgeries. The pulmonary function is impaired after the surgery, even after recovery of TOF ratio to 1.0.