The Effect of Doxapram Hydrochloride on the Ventilation Responses during General Anesthesia with Volatile Agent by Laryngeal Mask Airway / 대한마취과학회지

BACKGROUND: Inhalation anesthetics are known to depress ventilatory response to hypercapnea. Doxapram hydrochloride is an analeptic drug, which acts as a respiratory stimulant via peripheral and central chemoreceptors. Although the postoperarive infusion of doxapram hydrochloride is known to attenuate the impairment of respiratory function, no report is available on respiratory response to this drug when applied during anesthesia. Therefore, the present study aimed to evaluate the effect of doxapram hydrochloride on respiratory function during anesthesia. METHODS: Sixty adult patients undergoing operation under spontaneous ventilation via laryngeal mask airway (LMA) were randomly categorized into 3 groups: A control group, which received 5% dextrous infusion, and two groups in which patients were infused with doxapram hydrochloride (0.5 or 2 mg/kg/hr) starting 15 min after commencement operation. Anesthesia was maintained with 1 MAC sevoflurane - 4 L N2O - 2 L O2 under spontaneous ventilation via LMA. Tidal volume (VT), respiratory rate (RR), and arterial carbon dioxide tension (PaCO2) were measured just before and 15 min after the induction of anesthesia, 15 min after the start of operation and 15, 30, 45, and 60 min after the start of doxapram hydrochloride infusion. RESULTS: Measured values of RR and PaCO2 were significantly elevated during anesthesia venous those measured just before the induction of anesthesia in all groups. VT was significantly reduced during anesthesia venous just before the induction of anesthesia in all groups. All percent changes of VT, RR and PaCO2 were similar all any measurement times, and showed no significant changes after the infusion of doxapram hydrochloride in all groups. CONCLUSIONS: Intraoperative doxapram hydrochloride treatment did not produce any significant respiratory response improvement during 1 MAC sevoflurane anesthesia.

Effects of Fentanyl and Alfentanil on Cardiovascular Responses to Induction of Anesthesia and Endotracheal Intubation / 대한마취과학회지

BACKGROUND: The various methods have been used to prevent or minimize the increase of blood pressure and heart rate to endotracheal intubation. Opioids are the most widely used drug for hemodynamic stability. The purpose of this study was to compare the effects of fentanyl with those of alfentanil on hemodynamic changes to induction of anesthesia and endotracheal intubation. METHODS: Forty five patients were divided into three groups. They received intravenous fentanyl 1.0 microgram/kg, alfentanil 5 microgram/kg or saline 10 ml (control group), respectively. Baseline mean arterial blood pressure and heart rate were measured before the induction of anesthesia. Tracheal intubation was done 3 min after the injection of muscle relaxant. Mean arterial blood pressure and heart rate were measured every minute for 3 min after the induction of anesthesia and tracheal intubation and the results were compared with baseline value. RESULTS: Mean arterial blood pressure decreased significantly compared with baseline value after the induction of anesthesia, but there were no significant differences among the three groups. Heart rate initially increased and then decreased. After tracheal intubation, mean blood pressure and heart rate increased significantly in all groups. The extent of this was significantly lower in the alfentanil group and slightly lower in the fentanyl group than in the control group. CONCLUSIONS: Alfentanil is more effective than fentanyl at inhibiting cardiovascular responses following intubation, but further studies are needed to define the optimal injection time and drug dosage.