Intra-abdominal hypertension in obese patients undergoing coronary surgery: A prospective observational study

Abstract

BackgroundCoronary artery bypass grafting surgery has an increased risk of adverse events in obese patients. This increased risk might be explained in part by an increased intra-abdominal pressure and the development of intra-abdominal hypertension. Therefore, the objective of this study was to investigate the correlation between obesity and intra-abdominal hypertension and to evaluate its possible impact after coronary artery bypass grafting. MethodsA total of 50 consecutive patients scheduled to undergo coronary artery bypass grafting at a single center were selected prospectively before undergoing elective coronary artery bypass grafting. Based on the body mass index, 25 obese (body mass index ≥ 30) patients were matched with 25 control patients. Each patient had intra-abdominal pressure taken at baseline followed by one measurment every 4 hours until 24 hours after coronary artery bypass grafting. The serum markers for liver and kidney functions were collected once a day for 7 days after coronary artery bypass grafting. ResultsObese patients had a greater (mean ± SD) peak intra-abdominal pressure (15.4 ± 1.6 mm Hg versus 10.6 ± 1.6 mm Hg; P = .011) and mean change of intra-abdominal pressure from baseline (5.1 ± 3.3 mm Hg versus 2.2 ± 2.4 mm Hg; P = .001). The mean abdominal perfusion pressure was less in the obese group (63.0 ± 8.0 mm Hg versus 70.1 ± 11 mm Hg; P = .017). The liver dysfunction, as determined by the Schindl liver function scoring system between the obese and control groups, was not statistically significant (28% vs 8%; P = .066). More patients in the obese group developed renal injury based on the calculated glomerular filtration rate (32% vs 8%; P = .034). Obesity was highly associated with developing intra-abdominal hypertension (odds ratio: 2.99; 95% confidence interval: 1.92–3.53; P < .001). ConclusionObesity is associated with the development of intra-abdominal hypertension after coronary artery bypass grafting. This effect might indirectly impair the renal and liver functions through a decrease in the abdominal perfusion pressure.