In their interesting study comparing circulating B-type natriuretic peptide (BNP) concentrations in 13 patients with septic shock with those in 18 patients with sepsis but without shock and 18 age-matched healthy controls, Kandil and colleagues1 found that BNP elevation was correlated with severity of sepsis. They concluded that BNP measurement is useful for predicting the outcomes of patients with septic shock. The mean BNP concentrations, which were measured with a commercially available single-use fluorescence immunoassay, were 849.4 pg/mL in patients with septic shock, 120.0 pg/mL in those having early sepsis without shock, and 100.0 pg/mL in healthy controls. It appears that the method for determining circulating BNP levels has not been standardized. In a recent study that evaluated the validity of BNP as a predictor of postoperative cardiac events in patients undergoing major noncardiac operations, there was about a 25-fold increase in cardiac events in those with a BNP concentration of 108.5 pg/mL or greater, which was the optimal cutoff to discriminate patients at high risk for postoperative cardiac events from others.2 In another study, which included 204 patients undergoing major noncardiac surgery, using a cutoff of 40 pg/mL for preoperative BNP concentration identified patients with an almost 7-fold increased risk of cardiac events in the early postoperative period.3 I would like to ask the authors whether the change in BNP concentrations rather than the BNP value itself predicts the outcome of sepsis.
Fujita T. Significance of Circulating B-Type Natriuretic Peptide in Sepsis. Arch Surg. 2008;143(10):1021-1022. doi:10.1001/archsurg.143.10.1021-c