Can Brain Natriuretic Peptide Be Used as an Indicator of Over-infusion in Patients with Acute Sepsis? : A Pilot Study Evaluating Correlation Between Brain Natriuretic Peptide and Global End-diastolic Volume Index

Abstract Background: Recently, for patients with sepsis, under-infusion, that hastens the progression to multiple organ failure and death, has been avoided; however, the rate of over-infusion and resulting complications, such as mortality has increased. There are few indicators of over-infusion, such as transpulmonary thermodilution; therefore, minimally invasive, simple, and quick indicators of over-infusion are needed. This pilot study aimed to determine the association between brain natriuretic peptide (BNP) and global end-diastolic volume index (GEDI).Methods: This was a post-hoc analysis of a multicenter prospective randomized controlled study, performed in the intensive care units (ICU) of 10 separate hospitals in Japan from September 2013 to March 2016. Patients with sepsis who were expected to require mechanical ventilation for more than 48 hours were included. We measured BNP and GEDI every 24 hours from ICU admission until next 72 hours. The primary outcome was the correlation between BNP and GEDI that was assessed in two ways: 1) GEDI considered a continuous variable, and 2) GEDI divided into two groups based on a cutoff of 850 ml/m2, which is the upper limit of normal GEDI. We used a univariable generalized linear mixed-effects model in which patients are considered as a random effect.Results: Fifty-seven patients were analyzed. GEDI remained under the upper limit of normal GEDI (850 ml/m2) from ICU admission to 72 h, and there were no significant changes in the trends of BNP and GEDI over time. BNP tended to be higher in group 1 (GEDI >850 ml/m2) from ICU admission to 72 h, but there was no significant difference in the BNP values. The regression coefficient and 95%CI of BNP for GEDI were 2.5 and 1.3 to 3.7 when considered as a continuous variable, and 166 and -273 to 605 when divided into two groups based on GEDI cutoff of 850 ml/m2. Conclusion: There could be a weak but significant correlation between GEDI and BNP considering GEDI as a continuous variable. Using BNP as an indicator of over-infusion may be possible; however, further studies are needed.Trial registration: None.