Analysis of N-terminal pro-B-type natriuretic peptide and cardiac index in multiple injured patients: a prospective cohort study

Introduction Increased serum B-type natriuretic peptide (BNP) has
been identified for diagnosis and prognosis of impaired cardiac
function in patients suffering from congestive heart failure,
ischemic heart disease, and sepsis. However, the prognostic value
of BNP in multiple injured patients developing multiple organ
dysfunction syndrome (MODS) remains undetermined. Therefore, the
aims of this study were to assess N-terminal pro-BNP (NT-proBNP) in
multiple injured patients and to correlate the results with
invasively assessed cardiac output and clinical signs of MODS.
Methods Twenty-six multiple injured patients presenting a New
Injury Severity Score of greater than 16 points were included. The
MODS score was calculated on admission as well as 24, 48, and 72
hours after injury. Patients were subdivided into groups: group A
showed minor signs of organ dysfunction ( MODS score less than or
equal to 4 points) and group B suffered from major organ
dysfunction ( MODS score of greater than 4 points). Venous blood (5
mL) was collected after admission and 6, 12, 24, 48, and 72 hours
after injury. NT-proBNP was determined using the Elecsys proBNP (R)
assay. The hemodynamic monitoring of cardiac index (CI) was
performed using transpulmonary thermodilution. Results Serum
NT-proBNP levels were elevated in all 26 patients. At admission,
the serum NT- proBNP values were 116 +/- 21 pg/mL in group A versus
209 +/- 93 pg/mL in group B. NT-proBNP was significantly lower at
all subsequent time points in group A in comparison with group B (P
< 0.001). In contrast, the CI in group A was significantly
higher than in group B at all time points (P < 0.001).
Concerning MODS score and CI at 24, 48, and 72 hours after injury,
an inverse correlation was found (r = 0.664, P < 0.001).
Furthermore, a correlation was found comparing MODS score and serum
NT- proBNP levels (r = 0.75, P < 0.0001). Conclusions Serum
NT-proBNP levels significantly correlate with clinical signs of
MODS 24 hours after multiple injury. Furthermore, a distinct
correlation of serum NT-proBNP and decreased CI was found. The data
of this pilot study may indicate a potential value of NT-proBNP in
the diagnosis of post-traumatic cardiac impairment. However,
further studies are needed to elucidate this issue.