The relationship between body mass index, left ventricular ejection fraction, cardiopulmonary bypass time and glomerular filtration rate in coronary artery bypass graft surgery patients
Abstract:
Changes in glomerular filtration rates lead to acute renal failure in patients who are undergoing coronary artery bypass graft surgery. This descriptive research aimed to study the relationship between body mass index (BMI), left ventricular ejection fraction (LVEF), cardiopulmonary bypass time (CPB time), and glomerular filtration rate (GFR) in coronary artery bypass graft (CABG) patients. The sample comprised 88 patients who had undergone CABG and were admitted to two tertiary care hospitals in Bangkok. Data collection instruments were a general personal data form, a form for recording illness data, the BMI assessment form, the LVEF form, the CPB time form, and the GFR form. Descriptive statistics was employed to analyze the general personal data and the form for recording illness data while Pearsons product momentcorrelation coefficient was utilized to analyze the relationship between studied variables. The average age of the sample was 67 years. (SD ± 9.4). Most participants were male (71.6%). The patients had a GFR of 68.9 ml/min/1.73m2 (SD ± 24.2) within 24 hours after coronary artery bypass graft surgery and within 24-48 hours was 72.2 ml/min/1.73m2 (SD ± 24.4). The average of BMI was 24.4 kg/m2 (SD ± 4.2); the average LVEF was 54.7% (SD ± 14.0); the average CPB time was 144.4 minutes (SD ± 41.5). Factors correlated with GFR within 24 hours post CABG were LVEF and CPB time (r = 0.21, - 0.26; p < 0.05) and the factor correlated with GFR within 24-48 hours post coronary artery bypass graft surgery was CPB time (r = -0.25; p < 0.05). However, BMI did not correlate with GFR. The recommendation from this study is that patients who are undergoing coronary artery bypass graft surgery should be closely monitored, especially those who had prolonged cardiopulmonary bypass surgery more than 115 min and LVEF less than the normal range.