ED95 of Esmolol for Protection of Tachycardia and Systolic Hypertension by Endotracheal Intubation in Anesthetic Induction with Enflurane, Nitrous Oxide, Thiopental and Fentanyl / 대한마취과학회지

BACKGROUND: Esmolol has been used combined with small dose of fentanyl to prevent tachycardia and hypertension induced by tracheal intubation, but there has been few studies about the appropriate doses of esmolol when used combined with fentanyl. METHODS: According to esmolol dose, 140 patients were randomly allocated to 7 groups of 20 patients. After 2 microgram/kg of fentanyl, 4 mg/kg of thiopental and 0.12 mg/kg of vecuronium were intravenously administered, mask ventilation for 3 minutes with enflurane, nitrous oxide and oxygen was followed. Then one of the doses of esmolol, 0, 0.2, 0.3, 0.45, 0.6, 0.8 or 1.0 mg/kg was administered. Ninty seconds later, tracheal intubation by direct laryngoscopy was performed. After then heart rate was monitored continuously and blood pressure was measured 5 times with 1 minute interval. The highest heart rate and systolic blood pressure were recorded. We calculated the doses of esmolol which reduce the incidence of tachycardia (increased above 100 bpm or by more than 40% of preinduction level) and systolic hypertension (increased above 170 mmHg or by more than 40% of preinduction level) below 5% respectively. RESULTS: The ED95 of esmolol for prevention of tachycardia induced by tracheal intubation was 0.56 mg/kg (95% CI: 0.44-0.81 mg/kg). But the incidence of systolic hypertension was so low even without esmolol injection that the esmolol dose was not significant factor. CONCLUSIONS: In anesthetic induction and tracheal intubation with enflurane, nitrous oxide, thiopental, vecuronium, and fentanyl 2 microgram/kg, esmolol 0.56 mg/kg was ED95 of preventing tachycardia. But the incidence of systolic hypertension was acceptably low even without esmolol injection.

Is Muscle Relaxants Necessary during the Anesthesia for Cataract Surgery with LMA? / 대한마취과학회지

BACKGROUND: The recovery of spontaneous ventilation is delayed in elderly patients in whom muscle relaxants has been administered for general anesthesia. We evaluated the appropriateness of microscopic cataract surgery without using muscle relaxants in elderly patients. METHODS: Forty two ASA physical status I and II patients for cataract surgery were randomly assigned to two groups. Glycopyrrolate 0.2 mg, fentanyl 2 mcg/kg and propofol 2 mg/kg were administered intravenously followed by vecuronium 1 mg/kg iv in group I and 10% lidocaine 1.5 mg/kg spray into oropharynx in group II. Laryngeal mask (LMA) was inserted for airway management and anesthesia was maintained by only propofol infusion in both groups. Whether the patient moved during the surgery, whether ephedrine was administered and the propofol infusion rate were recorded. RESULTS: Six patients of group I and 1 patient of group II were moved during surgery. Only in group II, 7 patients received intravenously ephedrine administration. Mean infusion rate of propofol was 0.114 mg/kg/min in group I and 0.159 mg/kg/min in group II. CONCLUSION: In general anesthesia for microscopic cataract surgery, the combination of fentanyl 2 mcg/kg, propofol 2 mg/kg and infusion, 10% lidocaine spray and laryngeal mask without muscle relaxants is a good alternate method of keeping airway.

Is Muscle Relaxants Necessary during the Anesthesia for Cataract Surgery with LMA? / 대한마취과학회지

BACKGROUND: The recovery of spontaneous ventilation is delayed in elderly patients in whom muscle relaxants has been administered for general anesthesia. We evaluated the appropriateness of microscopic cataract surgery without using muscle relaxants in elderly patients. METHODS: Forty two ASA physical status I and II patients for cataract surgery were randomly assigned to two groups. Glycopyrrolate 0.2 mg, fentanyl 2 mcg/kg and propofol 2 mg/kg were administered intravenously followed by vecuronium 1 mg/kg iv in group I and 10% lidocaine 1.5 mg/kg spray into oropharynx in group II. Laryngeal mask (LMA) was inserted for airway management and anesthesia was maintained by only propofol infusion in both groups. Whether the patient moved during the surgery, whether ephedrine was administered and the propofol infusion rate were recorded. RESULTS: Six patients of group I and 1 patient of group II were moved during surgery. Only in group II, 7 patients received intravenously ephedrine administration. Mean infusion rate of propofol was 0.114 mg/kg/min in group I and 0.159 mg/kg/min in group II. CONCLUSION: In general anesthesia for microscopic cataract surgery, the combination of fentanyl 2 mcg/kg, propofol 2 mg/kg and infusion, 10% lidocaine spray and laryngeal mask without muscle relaxants is a good alternate method of keeping airway.