STUDY OF THE EFFECT OF LIDOCAINE OR VERAPAMIL ON SOME EXTUBATION RESPONSES

Abstract

Extubation of the trachea is ideally accomplished while the patient is still adequately anaesthe1ized to diminish coughing and laryngospasm. This assumes that the adequate ventilation of the lungs is present or can be maintained without the ETT and vomiting is not a likely hazard.

The ETT must be left in place until protective laryngeal reflexes have returned. Patients occasionally cough vigorously when allowed to wake up with the ETT ' in place, and this may strain recently placed sutures, produce arterial hypoxaemia and increase intracranial pressure.

Complications following extubation include oedema and stenosis either glottic, subglottic or tracheal. It is more serious in children because of the small larynx and loose submucosal tissue. Also hoarseness of voice due to vocal cord paralysis as a result of cuff compression or trauma to recurrent laryngeal nerve.

Laryngospasm caused by stimulation of the superior laryngeal nerve which could be accompanied by hypoxia, is triggered by pharyngeal secretions. Furthermore laryngeal trauma is more likely when the arytenoid cartilages attempt to close forceably around the ETT. Vigorous reaction to the tracheal tube , bucking , signals the return of the cough reflex and at this point either the ETT must be removed or further sedation instituted to permit tolerance of the ETT . Other measures include lidocaine or verapamil must be given before extubation to prevent coughing, hypertension and tachycardia which compromise more the cardiac patient .