Comparative study of stress response to central venous cannulation under local anesthesia and general anesthesia in patients undergoing open heart surgery.

The open heart surgery like coronary artery bypass graft (CABG), repair of ventricular septal defect (VSD) and atrial septal defect (ASD), valve replacement need a circulatory arrest, which is normally safe under conventional hypothermia. During this time not only the heart and lungs are bypassed but also a wide range of haemodynamic manipulation is necessary. For this reason continuous arterial and central venous pressure monitoring are mandatory. Arterial pressure is monitored by cannulation of the radial or femoral artery and central venous pressure is monitored from internal jugular, subclavian or femoral vein by inserting/placing a central venous access device (CVAD) in any of these veins. The study was designed to observe preoperatively the haemodynamic and humoral effects of central venous access device insertion under local anesthesia with premedication in patients of open heart surgery. In this study we compared the haemodynamic and humoral stress responses during central venous access device insertion under local anesthesia with those of under general anaesthesia. A total of 60 patients both male and female, age ranging from 20-65 years, having ASA grade I and II were randomly selected by a card selection method. They were equally divided into two groups (group-A and B) of 30 patients each. Again each group was subdivided into subgroup-I (20-40y) and II (>40-65y) according to their age distribution. Group-A was cannulated under local anesthesia with premedication and group-B was cannulated under standard general anesthesia. Before and after cannulation, the haemodynamic and humoral variables like blood pressure, heart rate, rate pressure product, ST segment changes were observed and serum cortisol levels were measured at a predefined time interval before and after completion of central venous cannulation. These values were compared between two groups in similar age group before and after cannulation. Data were recorded carefully at different time intervals. For estimation of serum cortisol level the sample was preserved at -30 degree celsius for estimation by Abbott AXSYM system (USA) in the Department of Biochemistry, BSMMU. All data were analyzed by using Student's 't' test in Statistical Program for Scientific Study (SPSS). From the study, we can conclude that central venous cannulation under local anesthesia in patients for open heart surgery has no significant changes of haemodynamic and humoral stress response in comparison to those of under general anesthesia. So, central venous access device can be placed under local anesthesia supported by premedication and it produces no significant changes in preoperative stress response in patients for open heart surgery.