Effects of maintaining a remifentanil infusion on the recovery profiles during emergence from anaesthesia and tracheal extubation.

BACKGROUND: Emergence from anaesthesia and tracheal extubation can be associated with hyperdynamic circulatory responses. We examined the effects of maintaining a remifentanil infusion on recovery profiles such as coughing and cardiovascular responses after general anaesthesia. METHODS: Forty patients undergoing endoscopic sinus surgery under general anaesthesia using total i.v. anaesthesia (propofol and remifentanil) were randomly allocated to a control group (n=20) or remifentanil group (n=20) during emergence from anaesthesia. At the end of surgery, propofol was ceased and the infusion of remifentanil was stopped in the control group and maintained in the remifentanil group at a target organ concentration of 1.5 ng ml(-1) until extubation. Heart rate (HR), mean arterial pressure (MAP), and recovery profiles were measured and evaluated. RESULTS: There was no significant difference in sex ratio, age, weight, height, time to eye opening, time to extubation, nausea, visual analogue scale, and time to discharge. Increases in HR and MAP occurred during emergence in the control group compared with baseline values. Increases in HR were attenuated in the remifentanil group and MAP decreased during recovery compared with baseline values. HR and MAP values were significantly higher in the control group [103 (23) beats min(-1), 129 (17) mm Hg] compared with the remifentanil group [79 (17) beats min(-1), 112 (15) mm Hg] during emergence and tracheal extubation. Moderate or severe coughing was observed only in the control group (8/20 vs 0/20, P<0.001). CONCLUSIONS: Maintaining a remifentanil infusion reduced haemodynamic changes and coughing associated with tracheal extubation almost without significantly delaying recovery from anaesthesia.

Effect-site concentration of remifentanil for laryngeal mask airway insertion during target-controlled infusion of propofol.

The purpose of this study was to determine the effect-site concentration of remifentanil that would provide optimal conditions for successful laryngeal mask airway insertion during a target-controlled infusion (TCI) of propofol at 3.5 microg.ml(-1) without the use of neuromuscular blockade. Five minutes after propofol infusion, remifentanil was infused at a dose determined by a modified Dixon's up-and-down method. Five minutes after remifentanil infusion, the laryngeal mask was inserted. The effect-site concentration of remifentanil for successful laryngeal mask insertion in 50% of adults (EC(50)) was 3.04 (SD 0.49) ng.ml(-1) during a TCI of 3.5 microg.ml(-1) propofol without neuromuscular blockade. From the probit analysis, the EC(50) and EC(95) of remifentanil were 2.84 ng.ml(-1) (95% CI 2.09-3.57 ng.ml(-1)) and 3.79 ng.ml(-1) (95% CI 3.26-9.25 ng.ml(-1)), respectively.

Exogenous pulmonary surfactant replacement therapy in a neonate with pulmonary hypoplasia accompanying congenital diaphragmatic hernia--a case report.

Pulmonary hypoplasia(PH) commonly occurs in association with oligohydramnios and other congenital anomalies, especially congenital diaphragmatic hernia (CDH). Pulmonary hypoplasia is an important factor, as persistent pulmonary hypertension, in the prognosis of CDH. In some reports, there is a decrement of pulmonary surfactant in PH accompanying CDH. Recently, there are some reports that exogenous pulmonary surfactant therapy is effective in experimental animal model and neonatal respiratory distress with PH. We report a case of a 5 day-old male neonate, who had shown dyspnea and diagnosed as left pulmonary hypoplasia accompanying CDH. The CDH was surgically treated and the ipsilateral PH, with intratracheal administration of exogenous pulmonary surfactant postoperatively. After exogenous pulmonary surfactant application, the left lung volume was increased on chest roentgenogram and lung perfusion scan findings, and there was an improvement in oxygenation and clinical manifestations. We suggest that postoperative exogenous pulmonary surfactant replacement therapy is effective in the case of PH and further trials are needed to clarify the optimal dose and timing of supplementation of surfactant for treatment of infants with PH accompanying CDH.