Back ground: Direct laryngoscopy and endotracheal intubation frequently induces a cardiovascular stress response characterized by hypertension and tachycardia and also hormonal stress response characterized by increased secretion of pituitary hormones.
The present study was undertaken to compare the efficacy of intravenous dexmedetomidine, lidocaine and magnesium sulphate in attenuating the stress response to direct laryngoscopy and endotracheal intubation.
Subjects and Methods: The current prospective randomized clinical study was performed in Zagazig University hospitals. A total of 87 patients posted for elective abdominal surgeries under general anesthesia were enrolled in the study. Patientswere randomly divided into three groups, group-D (dexmedetomidine group), group-L (lidocaine group) and group-M (magnesium sulphate group) with 29 patients in each group.
Group-D was given 1mcg/kg dexmedetomidine , Group-M was given 30mg/kg of magnesium sulphate and Group-L was given 1.5mg/kg lidocaine all the study drugs were given by IV infusions over a period of 10 minutes before induction of anesthesia which was standardized for all patients. The three groups were observed for changes in hemodynamic parameters at preinfusion of the study drug and preinduction of the anesthesia and 1, 3,5,10 minutes post intubation, blood glucose and cortisol level were measured at preinfusion and 10 min after intubation, Ramsay sedation score and postoperative pain were assessed at preinduction period and 1 hour postoperatively.
Results:It was observed that both dexmedetomidine and magnesium sulphate attenuated the rise in the mean arterial blood pressure significantly, but lidocaine failed to attenuate it.Also dexmedetomidine only decreased the changes in the mean heart rate , serum cortisol, serum glucose level, Ramsay sedation score and postoperative pain significantly.
Conclusion: This study seems to prove that dexmedetomidine and magnesium sulphate play an important role in blunting the stress response resulting from direct laryngoscopy and intubation.