Changes in Haemodynamics and Plasma Catecholamine concentration following Endotracheal Intubation and LMA Insertion

Background: Laryngopressor response follows tracheal intubation (TI) and may be deleterious in patients with cardiac and cerebral diseases. The Laryngeal mask airway (LMA) attenuates this response as it does not require laryngoscopy.Objective: To compare the changes in haemodynamics and plasma norepinephrine and epinephrine following tracheal intubation and LMAinsertion.Materials and Methods: Sixty adult patients, scheduled for elective surgeries under general anaesthesia were randomly allocated into Group A (n=30) endotracheal intubation (ETI) and Group B (n=30) LMA insertion after propofol 2-3mg/kg and atracurium 0.5mg/kg induction.  Norepinephrine and epinephrine assay were performed one minute before and one and five minutes after intubation/airway insertion. Haemodynamic variables were noted every minute.Results: Demographics, baseline clinical parameters and catecholamine levels were similar in both groups. Both groups exhibited significant increase in norepinephrine 1 minute after insertion (p<0.001) but the mean levels in ETI group (237.4 ± 148.8) vs LMA (161.0 ± 50.6) were significantly higher (p=0.017). There was a significant increase in epinephrine 1 minute after intubation in the endotracheal tube (ETT) group only (p<0.05). Non-significant differences in epinephrine were noted 1 and 5 minutes post airway insertion (p= 0.313 and 0.456 respectively). Heart rate increased significantly one minute after introduction of both airway devices (p<0.05) but remained elevated in the ETTgroup only. MAPwas significantly higher in the ETTgroup at 1 and 2 minutes after intubation (p<0.05).Conclusion: Laryngoscopy and tracheal intubation causes raised plasma catecholamines with increase in haemodynamic variables. This could be harmful in patients with cerebrovascular or cardiovascular pathology. LMA insertion may be advantageous and is therefore recommended if applicable. Keywords: Laryngeal Mask Airway, Laryngoscopy, Catecholamines, Haemodynamic