EFFECT OF CARDIOPULMONARY BYPASS DURATION ON POSTOPERATIVE MEDIASTINAL BLEEDING WITH COAGULOPATHY IN CORONARY ARTERY BYPASS GRAFT (CABG) SURGERY

Abstract

Objective: To determine the effect of cardiopulmonary bypass (CPB) duration asa risk factor in the incidence of postoperative mediastinal bleeding withcoagulopathy in elective CABG surgery.

Methodology: Our study was cross-sectional and retrospective done atDepartment of Cardiac Surgery and Anaesthesia at the National Institute ofCardiovascular Diseases, Karachi, from 1st February 2013 to 31st January2015. The demographic, operative and postoperative data were collected. Thetime for CPB and aortic cross clamp time was noted. Postoperative mediastinalbleeding was measured through the mediastinal drains. The patients'prothrombin time /international normalized ratio (PT/INR), activated partialthromboplastin time (aPTT), platelet count and haemoglobin were documentedand the patients with significant mediastinal bleeding with raised PT/INR, aPTTand thrombocytopenia were treated conservatively with fresh frozen plasma,platelets and blood or surgical re-exploration if required. Analysis of Variance(ANOVA)was used to analyse the data and a p<0.05was considered statisticallysignificant.

Results: Total of 110 patients were included in the study. Our study revealed thatthe mean CPB time (minutes) was 75.2±11.6 minutes (range: 62 to 137minutes). In 5 patients (4.55%) the CPB timewas greater than 100minutes. Postoperativemediastinalbleeding was increased in 4 (3.64%) out of the five patientsin whom the cardiopulmonary bypass time was greater than 100 minutes(p<0.05). Mean postoperative mediastinal bleeding of 1.5 ml//kg/hour occurredwhen the immediate postoperative blood platelet count was less than or equal to90 X 10 /l (p < .05). In all these patients the PT/INR,APTT was raised above 9 4normal and there was thrombocytopenia (coagulopathy). Out of these 4 patients3 (2.73%) patients were successfully treated conservatively with transfusion offresh frozen plasma and platelets, while 01 (0.91%) patient required surgical reexplorationas he developed cardiac tamponade.

Conclusion: Prolonged cardiopulmonary bypass time is a risk factor for postCABG mediastinal bleeding with coagulopathy.