RESUMO
Observations of arterial blood pressure, heart rate and cardiac rhythm during endotracheal intubation and within a five minute period thereafter were made in 80 patients randomly assigned into four groups. The aim was to study the cardiovascular changes following endotracheal intubation using a standard anesthesia technique and to compare the efficacy of lidocaine in controlling cardiovascular changes using different administration techniques. Anesthesia was induced with thiopentone and succinylcholine followed by endotracheal intubation. In group A, the control group, no lidocaine was given. In groups B, C, and D, lidocaine as laryngotracheal spray, transtracheal injection or intravenous injection in a dosage of 1 mg/kg BW was administered prior to endotracheal intubation. In the control group, laryngoscopy and endotracheal intubation caused a significant rise in blood pressure and heart rate with a high percentage (60%) of cardiac dysrhythmias including serious types. In the lidocaine groups, we observed significantly lower values of blood pressure and cardiac dysrhythmias as compared to the control group. Only 20-25% of the cases showed sinus tachycardia. No significant differences were noticed between the lidocaine groups. We conclude from our study that those patients who had received lidocaine prior to endotracheal intubation showed minimal cardiovascular changes. Lidocaine should therefore routinely be used prior to endotracheal intubation.
