Understanding the Haemodynamic response to Laryngoscopy and Intubation –Review article.

Abstract

This review is designed to present a concise description of the state of knowledge of the haemodynamic response to laryngoscopy and endotracheal intubation, with the aim of improving understanding of the phenomenon. Laryngoscopy and endotracheal intubation cause reflex increases in heart rate and blood pressure, as well as abnormalities of cardiac rhythm. While this is of little clinical consequence in healthy patients, it could be dangerous in patients with neurovascular and cardiac diseases. The physiological/ pathophysiological basis of the phenomenon, as well as the best methods of controlling it are not fully elucidated. It is however believed to be a reflex sympathetic and sympatho-adrenal response to airway stimulation or irritation. While the afferent limb of the reflex arc is via the cranial nerves of the upper airway, the efferent limb is via the sympathetic nerves. However, the central integrating
station is not satisfactorily described in the literature. This is appraised, and we proffer opinion on the grey areas, based on present state of scientific/medical knowledge. We highlight the historical identification of the phenomenon as well as the development of knowledge about it over the years. We have assembled and appraised the various methods reported over the years to attenuate the pressor response to laryngoscopy and endotracheal intubation. We believe that a good understanding of the phenomenon is a sine qua non to managing it in individual patients.