Comparison of Brain Natriuretic Peptide (BNP) Levels in Patients Under General or Spinal Anesthesia

Özet

Introduction: Many hemodynamic parameters are affected according to selected anesthesia type in patients under general or spinal anesthesia. In recent years, brain natriuretic peptide (BNP) has been frequently used in clinical follow-up. It is released from the heart ventricles and is directly proportional to increased ventricular dilatation and pressure load, suggesting cardiac performance. We aimed to compare the cardiac effects of general and spinal anesthesia with BNP values in noncardiac small surgical operations where hypovolemia is unexpected. Methods: The study was conducted between January and May 2009 after obtaining the approval from the ethics committee at the Haydarpaşa Numune Training and Research Hospital. Our patient group consisted of 44 patients (15 women and 29 males), aged between 45 and 80 years, scheduled for ASA 2-3, NYHA 2-3, describing exercise dyspnea at the end of 5 min walking test, with an ejection fraction of 40%–55%, hypovolemia unexpected small surgery planned (inguinal hernia, urinary incontinence, rectocele, cystocele, etc.). Patients were randomly assigned to two groups to receive general anesthesia and spinal anesthesia. Venous blood was taken, and the BNP levels were measured 30 min before the operation, 25 min after anesthesia, and 8 h after the operation. Results: In General and Spinal Anesthesia group, there was no significant change in the 25th-min BNP level according to the preoperative BNP level (p>0.05); the increase in the 8th-hour BNP level was statistically significant (p 0.05), while the percent change in BNP level at 8th hour according to preop of spinal anesthesia group was significantly higher than general anesthesia group (p<0.05). Discussion and Conclusion: In our study, postoperative BNP increase was observed in patients who underwent both general and spinal anesthesia. This increase is statistically more significant in spinal anesthesia. This difference shows that the cardiac performance of patients in the spinal anesthesia group is more affected.