Attenuation of hemodynamic stress responses during extubation with intravenous diltiazem versus intravenous lignocaine in patient undergoing elective laparoscopic surgeries - a prospective randomised control study

Endotracheal extubation is the translaryngeal removal of a tube from the trachea via the nose or mouth. Endotracheal extubation almost always associated with haemodynamic changes due to reflex sympathetic discharge caused by epipharyngeal and laryngopharyngeal stimulation. This increase in sympathoadrenal activity may result in hypertension tachycardia and arrhythmias. In addition, many other stimuli affect these hemodynamic changes including pain from wound and emergence from anaesthesia.These hemodynamic changes during extubation and emergence from anesthesia may cause dangerous increases in myocardial oxygen demand in patients with coronary artery disease CAD and in those with risk factors for CAD.

Laparoscopic procedures are also associated with several undesirable cardiorespiratory perturbances. A combination of several factors, namely pneumoperitoneum, patient position, anaesthesia and hypercapnia from the absorbed CO2 are responsible for the haemodynamic changes observed during laparoscopy. These includes increased HR increased arterial pressures, increased systemic vascular resistance and increased pulmonary vascular resistance. Hemodynamic changes induced by the pneumoperitoneum and more particularly the increased systemic vascular resistance outlast the release of the pneumoperitoneum. Thus, at the end of the procedure, even when intra-peritoneal pressure has returned to normal the heart rate and arterial pressure remain elevated. These changes may add on to the changes provoked by extubation.Many pharmacological methods have been devised to reduce the extent of hemodynamic events, including esmolol, alfentanil, fentanyl, diltiazem, high dose of opioids, local anaesthetics like lignocaine and vasodilating drugs like nitroglycerine.

Lignocaine, a sodium channel blocker, attenuates the hemodynamic response to tracheal extubation by inhibiting sodium channels in the neuronal cell membrane, decreasing the sensitivity of the heart muscles to electric impulses. Diltiazem, a calcium channel blocker, attenuates hemodynamic response by blocking voltage sensitive L type channels and inhibiting calcium entry mediated action potential in smooth and cardiac muscle. So, the present study was undertaken to study and compare the effect of intravenous diltiazem and intravenous lignocaine on attenuation of hemodynamic responses to endotracheal extubation in patients undergoing laparoscopic surgeries.