A Comparative Study Of Ocuronium Residual Paralysis During Total Intravenous Anesthesia In Children And Adults

Objective General intravenous anesthesia has many advantages, such as rapid induction, without stimulation to the respiratory tract, stable maintenance of anesthesia and so on, therefore it is now used in clinic widely. Rocuronium is a new intermediate-duration nondepolarizing relaxant which has the most rapid onset of action in clinic at present and could be used for rapid intubation comparable with succinylcholine. Pediatric patients are the special cases, in whom physiology, pathophysiology, pharmacokinetics and pharmacodynamics are distinct from those in adults. The purpose of this study was to assess the incidence and severity of residual paralysis at the time of tracheal extubation and on arrival to patients'room after using rocuronium during TIVA (total intravenous anesthesia, TIVA) in children and adult.Methods 30 adults (18 years to 60 years) and 30 children (3 years to 10 years) presenting for gynecologic, general, plastic or orthopedic surgical procedures were enrolled. For the children, who did not cooperate, were given 5mg·kg^-1 ketamine by intramuscular injection before they were in operation room. All subjects were induced with propofol, remifentanil and rocuromium (0.6mg·kg^-1) to facilitate tracheal intubation, maintained with continunous intravenous infusion of propofol and remifentanil. Neuromuscular monitoring was performed using the TOF Watch SX acceleromyograph. Neuromuscular blockade was maintained with continunous intravenous infusion of rocuronium at T1≤0.15. All subjects were mechanically ventilated to keep PETCO2 at 35～45mmHg. When the operation was over, all subjects were reversed with neostigmine 0.02～0.04mg·kg^-1 and atropine 0.01～0.02 mg·kg^-1 at T1 0.25. Neuromuscular recovery achieved by using standard clinical criterias (5s head lift﹑hand grip﹑leg raising, or continuing tongue deflector test, eye opening on command, respiratory frequency 8¹0 times·min^-1, tidal volume 8ml¹2mg·kg^-1, SpO2>95% inhalation of the air) and the twitch height of thumb(no evidence of fade with TOF). One anesthesiologist who did not know the study decided the time of tracheal extubation by using the criterias above and arrival to patients'room. TOFR (TOF Ratio, TOFR) were recorded at the time of tracheal extubation and on arrival to the patients'room. TOFR<0.7 means residual paralysis.Results Both groups had high incidence of residual paralysis at the time of extubation, but the incidence was lower in children than in adults (46.7% vs 83.3%,P<0.05), while the mean TOFR was greater in children than in adults (0.71±0.21 vs 0.49±0.22,P<0.05). On arrival to patients'room, the incidence of residual paralysis was 6.7% in children group versus 26.7% in another group (P<0.05).Conclusions There is a high incidence of residual paralysis after rocuronium administration during TIVA, although it is lower in children than in adults. Few individuals'neuromuscular function can recovery completely at the time of extubation.