Comparative Study of Cardiovascular Response to Lma Insertion and Endotracheal Tube Intubation

Abstract

BACKGROUND Tracheal intubation is performed routinely during general anaesthesia to secure the airway, to facilitate ventilation of the lungs, for control of partial pressures of oxygen and carbon dioxide in arterial blood. Laryngoscopy and intubation are associated with tachycardia, hypertension and arrhythmias. Placement of LMA is effective in securing the airway. Its insertion does not require Laryngoscopy and its placement is less stimulating and produces less catecholamine release; hence, there is no tachycardia, hypertension and arrhythmias. The aim of the study is to analyse the cardiovascular response to LMA and ETT insertion. MATERIALS AND METHODS This study was done to evaluate the cardiovascular response to intubation following insertion of LMA and ETT. This is a prospective, non-randomised, clinical study of 110 patients admitted to KAP Viswanatham Medical College Hospital, Trichy, during 2002-04 to undergo elective surgical procedures. Overall, 110 patients were found to have the satisfying criteria and they were all included in the study and alternatively allotted to each group, hence the sample size is 110. The patients were in the age group of 14-70 years. RESULTS Two sample student's 't' test and standard error of mean test were used for statistical analysis of the parameters obtained in the study. The following are the results obtained in our study. The heart increased by 15.54% following endotracheal intubation and by 9.91% following laryngeal mask insertion. The systolic blood pressure showed an increase of 14.13% in endotracheal group and 4.88% in laryngeal mask group. The diastolic blood pressure increased by 17.73% in endotracheal group and 27.27% in laryngeal mask group. The rate pressure product increased by 31.26% following endotracheal intubation and 14.20% following laryngeal mask insertion. The incidence of premature ventricular contraction is 9.09% following endotracheal intubation and 3.64% following laryngeal mask airway insertion. CONCLUSION This study shows that a considerably less cardiovascular response is produced by insertion of the laryngeal mask airway compared with direct Laryngoscopy and Endotracheal intubation. The laryngeal mask airway may be useful in situations where the pressor response to endotracheal intubation should be avoided, for example during induction of anaesthesia in an hypertensive patient.