Yonago Acta medica 1997;40:1–11
Release of Brain Natriuretic Peptide during the Perioperative Period of Cardiac Surgery
Keisuke Morimoto, Shingo Ishiguro and Hiroaki Kuroda
Second Department of Surgery, Faculty of Medicine, Tottori University, Yonago 683, Japan
Brain natriuretic peptide (BNP) is well known as a cardiac hormone. To examine the release of BNP in patients undergoing cardiac surgery with cardiopulmonary bypass and to investigate the relationships between plasma BNP concentrations and various clinical parameters, we measured the arterial plasma BNP level in 17 consecutive adult patients during the perioperative period, and compared it with the level from another cardiac hormone, atrial natriuretic peptide (ANP). The mean preoperative plasma BNP level (baseline) was 63.8 ± 34.4 pg/mL (mean ± SD). A slight decrease in the mean plasma BNP level was observed during cardiopulmonary bypass (CPB) surgery. After the cessation of CPB, however, the mean plasma BNP level gradually increased, and a significant increase was observed 12, 24 and 48 h after the cessation of CPB (mean ± SD; 149.5 ± 43.0 pg/mL, 175.2 ± 93.6 pg/mL and 146.2 ± 59.4 pg/mL, respectively; P < 0.01, P < 0.01 and P < 0.01, respectively). The mean value 3 weeks after the operation was similar to that before the operation. The plasma ANP levels did not significantly change during the same time course. The plasma BNP as opposed to the ANP concentration 12 h after CPB significantly correlated with the cardiac index (r=–0.52, P < 0.05), current injection rate of dopamine hydrochloride (r=0.51, P < 0.05), aortic crossclamp time (r=0.55, P < 0.05) and peak postoperative serum creatine phosphokinase level (r=0.82, P < 0.01). We conclude that plasma levels of BNP are markedly elevated in the acute phase after cardiac surgery requiring bypass and reflect the left ventricular function at the same time. Furthermore, myocardial damage due to ischemia may participate in the mechanism of synthesis and secretion of BNP.
Key words: atrial natriuretic peptide; brain natriuretic peptide; cardiac surgery; cardiopulmonary bypass
