The impact of blood use on patients undergoing coronary artery bypass surgery: a prospective study

This survey aimed at assessing the incidence of blood use and the impact of cardiopulmonary bypass (CBP), sex, age, number of grafts, combined cardiac interventions, and hematocrit level in patients who undergo coronary artery bypass graft (CABG) surgery.

A prospective study included patients in the department of cardiac surgery at the American Hospital, in Tirana, Albania. We studied 164 consecutive patients who underwent CABG surgery over a 2-year period (2011-2013).

We analyzed 164 patients: 138 men and 26 women. The average age was 61.8 years (range, 34-82 years). Of these, 116 patients (101 men/15 women) and 48 patients (37 men/11 women) were operated on-pump and off-pump, respectively. Packed red blood cells (PRBC) were administered to 79.87% of patients (131/164). In total, 334 units were transfused. The average number of PRBC units per patient was 2.03 ± 1.5 (range, 0-8 units). Blood transfusion was administered to 87.06% and 62.5% of on-pump and off-pump patients, respectively. On-pump and off-pump patients received 2.4 and 1 unit of PRBC, respectively (p < 0.001). Female and male patients received 2.2 and 2 units, respectively (p = 0.1). Patients aged ≥ 62.5 years received 2.3 units on average versus the average of 1.7 units received by patients aged < 62.5 years (p < 0.001). Interventions with 4-6 grafts (79/164) received an average 2.5 units, while those with 1-3 grafts (85/164) received 1.5 units (p < 0.001). Patients requiring other cardiac surgical interventions (35/164) received an average of 2.6 units, while those without other cardiac surgical interventions (129/164) received an average of 1.8 units (p < 0.001). Patients with preoperative hematocrit < 35% received an average 1.2 units of PRBC intraoperatively, and 2.8 units throughout the hospital stay, while patients with preoperative hematocrit ≥ 35% received an average of 0.75 units intraoperatively (p < 0.001) and 1.9 units throughout the hospital stay (p < 0.001).

Blood transfusion was required for 79.87% of patients. Five variables were important factors in the use of blood in patients undergoing CABG: using CBP, a higher number of grafts, age ≥ 62.5 years, combined heart interventions and preoperative hematocrit< 35%. Female patients required more PRBC than male patients, although it was not statistically significant. Knowledge of these risk factors enables better prediction of the probability of patients who might require more blood, better distribution of blood in CABG procedures, use by the blood bank, and evaluation of cost-effectiveness in the use of blood products.