Pain Location and Intensity During the First Week Following Coronary Artery Bypass Graft Surgery

Background: Despite the advances in pain control following surgery, data on the location and distribution of pain following coronary artery bypass grafting (CABG) are lacking. Objectives: This study was intended to investigate the location, distribution, and intensity of pain in patients undergoing CABG during their postoperative hospital stay from the operation to the end of the first postoperative week. Factors that could affect pain intensity and distribution were analyzed as well. Patients and Methods: The present study was conducted on 138 patients who underwent CABG surgery at Rajaei cardiovascular, Medical and Research Center during May and July 2011. Location and intensity of pain were assessed using numeric rating scale (NRS) over time: every six hours after the operation on the first day (T1-T4, respectively), and on two (POD2), three (POD3), and seven days after the operation (POD7). Results: Among 138 patients assessed in the study, the greatest severity of pain was reported on T2, with the mean severity of 3.4, followed by POD2 with the mean severity of 2.9 (P < 0.01). The location of the surgical incision had the most severity of pain in all patients (P < 0.01). On the site of surgical incision, a negative correlation was seen between the age and the severity of pain on T1 (P = 0.03, r = -0.180). Women experienced more severe pain compared to men at POD7. A significant correlation was seen between the severity of pain on POD7 and body mass index (BMI) (P < 0.01, r = 0.23). In patients who had the longer duration of cardiopulmonary bypass (CBD), the most pain intensity was reported on T1 (P < 0.01, r = 0.18). A significant correlation was seen on the pain intensity on T4 and chest tube drainage (P < 0.01, r = 0.24). The correlation between the pain severity pain and duration of admission in intensive care unit (ICU), was significant on T1 (P < 0.05, r = 0.18), T4 (P < 0.01, r = 0.29), POD2 (P < 0.01, r = 0.35) and POD7 (P < 0.05, r = 0.18). Conclusions: Following CABG, the most severity of pain was reported at surgical incision on time T2. Pain began to decrease from the third day following the operation. Age, sex and BMI along with operation-related factors such as duration of CBP or chest tube drainage may affect the pain pattern following CABG surgery.