The dose-dependent effect of remifentanil for withdrawal responses on injection of recuronium in children

BACKGROUND: The injection of rocuronium causes pain and withdrawal responses. This study was designed to determine an appropriate dose of remifentanil to prevent the withdrawal responses associated with injection of rocuronium in children. METHODS: Fourty five ASA physical status I and II pediatric patients were randomly allocated into three groups; Group I (placebo; normal saline 3 ml, n = 15), Group II (remifentanil 0.3microg/kg, n = 15), Group III (remifentanil 0.5microg/kg, n = 15). After the induction of anesthesia with 5 mg/kg of thiopental sodium, patients in groups I, II, and III received normal saline 3 ml, remifentanil 0.3microg/kg, and remifentanil 0.5microg/kg, respectively. After one minute, rocuronium 0.6 mg/kg was injected over 10 seconds. The patient's response after injection was graded using a four-point scale. The patient's heart rate (HR), mean arterial pressure (MAP) were measured at pre-anesthesia (T0), 1 minute after injection of thiopental sodium (T1), test drug (T2), and rocuronium (T3). RESULTS: The incidence of withdrawal responses was 100%, 66.7%, and 20% in groups I, II, and III, respectively. In addition, the severity of withdrawal responses was lowest in group III. CONCLUSIONS: Remifentanil 0.5microg/kg was an appropriate dose to prevent the withdrawal responses on injecting rocuronium.

Thermoregulatory responses of sevoflurane, desflurane, and isoflurane during gynecologic laparoscopic surgery / 대한마취과학회지

BACKGROUND: Core temperature decreases rapidly after the induction of general anesthesia, because the heat is redistributed to peripheral tissues. Thermoregulatory responses of volatile anesthetics have been tested, but their effects have not been directly compared. Therefore, we evaluated the thermoregulatory responses to sevoflurane, desflurane, and isoflurane. METHODS: Sixty healthy patients scheduled for laparoscopic myomectomy or radical hysterectomy were allocated into three groups; Group S (sevoflurane, n = 20), Group D (desflurane, n = 20), and Group I (isoflurane, n = 20). Anesthesia was maintained with 1 minimum alveolar concentration (MAC) of sevoflurane, desflurane, and isoflurane in a 50/50 mixture of N2O/O2. Patients were maintained in a normovolemic and normocapnic state. The core temperature and forearm minus fingertip skin-temperature gradient (an index of peripheral vasoconstriction) were monitored after the induction of general anesthesia. RESULTS: Each of the seven patients given sevoflurane, desflurane, and isoflurane vasoconstricted at a core temperature of 35.3 +/- 0.5degrees C, 33.6 +/- 0.4degrees C, and 35.2 +/- 0.4degrees C, respectively. The vasoconstriction threshold was the lowest in patients anesthetized with desflurane. The core temperature gradient (Ti-Tf) was significantly higher in patients that were anesthetized with desflurane than in those that were anesthetized with sevoflurane or isoflurane. The core temperature of desflurane was significantly lower than that of sevoflurane or isoflurane 15 minutes after the induction of anesthesia until 180 minutes of anesthesia. CONCLUSIONS: These results indicate that the core temperature is maintained at a higher level in patients that have been anesthetized with sevoflurane or isoflurane than in those that have been anesthetized with desflurane.