Dr Fujita raises important issues. Natriuretic peptides emerged during recent years as potent prognostic markers in patients with heart failure and acute myocardial infarction. In addition, natriuretic peptides show strong predictive value in patients with pulmonary embolism, sepsis, renal failure, and shock. Our recently published study tests the prognostic information of BNP in a cohort of critically ill patients with septic shock. We have demonstrated that BNP concentrations are significantly increased in patients with septic shock and may play an important role in risk stratification in these patients independent of congestive heart failure. It could very well be that changes or the rate of elevation in BNP concentrations may be an important component of disease prognostication in sepsis. Similar concerns were raised when prostate-specific antigen was being investigated as a marker for prostate cancer. Numerous approaches were deemed of value with respect to prostate-specific antigen disease prognostication, including rate of rise, bound vs free prostate-specific antigen, and Gleason score correlation among others.1 Furthermore, variation in methods of analyte determination may very well render similar studies that are incomparable, as normal values may vary with differing analytical methods.2 Time will tell if BNP shares similar issues as a prognosticator in sepsis. Nonetheless, we believe it may be critical to patient management that a single measurement of BNP might facilitate triage of emergency department and intensive care unit patients and predict the outcome of sepsis. A single elevated BNP concentration on admission to the intensive care unit in these patients was significantly associated with mortality. The data presented in our Figure 2 (22 data points from 13 patients) reflect BNP concentrations drawn at initial diagnosis and the subsequent first and fourth days. The difference in data points was due to the inability to draw blood from some of the patients at the appropriate time.
Kandil E, Bluth MH. Significance of Circulating B-Type Natriuretic Peptide in Sepsis—Reply. Arch Surg. 2008;143(10):1022-1023. doi:10.1001/archsurg.143.10.1022