Clinical observation on the necessity of skeletal muscular relaxation monitoring in post-anesthesia care unit

Objective To determine if it is necessary to use skeletal muscular relaxation monitoring in the PACU. Methods Two hundred and sixty-two patients, aged 20-90 y, BMI 16-28 kg/m2, of ASAⅠ-Ⅲ, scheduled for surgery under general anesthesia. The cisatracurium was the only neuromuscular blockade agent used during general anesthesia. Monitored the train of four stimulation(TOF) at the time before tracheal extubation (T1), 30 min after tracheal extubation(T2), the time of patients discharged from PACU(T3). The other parameters of patients were also recorded including demographic information, the anesthesia agents and the muscle relaxation antagonism, the length of stay in the PACU and the incidence of hypoxemia. Results The incidence of residual neuromuscular blockad(RNMB) was 76.7%(T1), 46.6%(T2), 21.0%(T3) respectively, the incidence of RNMB between time elapsed from the last administration of cisatracurium to tracheal extubation≤90 min was more than>90 min (P<0.01). The incidence of RNMB in the younger group (20-40 y) was lower than the elderly group (66-90 y)(P<0.05), The length stay in PACU of the patients with TOF ratios<0.9 was longer than the patients with TOF ratios≥0.9 when discharged from PACU(P<0.05). The mean time from using muscle relaxation antagonism to TOF ratio reach 0.9 was(9±5) min. Conclusions The incidence of RNMB was very common in the PACU. It is necessary to monitor the neuromuscular blockade using skeletal relaxation monitoring before the determination of the extubation and the patients transferred to general surgical floor. The antagonism of neuromuscular blockade agent is a safe measure to reduce the incidence of RNMB. Key words: Residual neuromuscular blockade; Neuromuscular monitoring; Cisatracurium; Post-anesthesia care unit