Fiberoptic intubation: evaluation of two methods to obtund the pressor response

This study was performed on 40 adult patients to compare the efficacy of pretreatment with fentanyl or lidocaine IV. for supression of haemodynamic stress response in nasotracheal oriorotracheal fiberoptic intubation. Heart rate, mean arterial blood pressure, rate-pressure product showed significant decrease after fentanyl pretreatment which provided a good opportunity for successful a wake fiberoptic intubation inspite of minimal cardiovascular instability in the form of ventricular extrasystole in 3 patients. Also IV. lidocaine was effective in attenuating but not completely blocking cardiovascular response. In conclusion, fiberoptic intubation provided the better visualization of tissues and vocal cords; thus, decreasing the possibility of mechanical trauma but needs a good training program. Pretreatment with fentanyl and/or lidocaine should be used in an attempt to combat the cardiovascular responses during fiberoptic intubation, especially in patients in whom the pressor response to intubation is particularly hazardous

effect of magnesium sulphate on the duration of epinephrine induced ventricular arrythmia in halothane anaesthetized dogs

The effect of magnesium sulfate infusion on the duration of epinephrine induced ventricular arrythmia was evaluated in halothane anesthetized dogs. MgSO4 infused at a rate of 8 mg/kg/min. for 20 minutes caused a significant reduction in epinephrine arrhythmic threshold dose. Twenty minutes infusion of MgSO4 [8 mg/kg/min.] were compared with propranolol [0.03 mg/kg/min.] and verapamil [0.5 mg/kg/min.] and saline infusion on the duration of arrhythmia after epinephrine [12 ug/kg] injection in halothane anesthetized dogs. MgSO4 and propranolol infusion caused a significant reduction in the duration of arrhythmia [85% and 75%, respectively]. Verapamil infusion caused a significant reduction from the control value, but only by 48%. There was no significant difference between MgSO4 and propranolol both caused a significant greater reduction in arrythmia than verapamil