title: N-terminal pro-B-type natriuretic peptide in patients with isolated traumatic brain injury: a prospective cohort study.
abstract: BACKGROUND
  The role of brain natriuretic peptide (BNP) after traumatic brain injury (TBI) remains unclear, and its relationship with hyponatremia is still controversial. The aim of this study is to investigate the secretion pattern of N-terminal (NT)-proBNP in patients with TBI and to assess the relationship between NT-proBNP, sodium balance, and intracranial pressure (ICP).
  
  
  METHODS
  We measured serum NT-proBNP levels of 84 patients with isolated TBI on a daily basis from day 1 to day 14 after injury.
  
  
  RESULTS
  In average, the peak of BNP level was measured at 703.9 pg/mL±179.1 pg/mL on day 3 after injury, which was correlated to the severity of TBI. Among patients with severe TBI, plasma NT-proBNP concentrations in patients with hyponatremia were statistically higher than those without hyponatremia (p<0.05). In the hyponatremic group, the plasma NT-proBNP increased to a peak of 1001.16 pg/mL±131.52 pg/mL within 48 hours after injury and maintained at a high level for 3 days. In the normonatremic group, the plasma NT-proBNP reached a peak of 826.43 pg/mL±337.43 pg/mL on day 5 and quickly decreased thereafter. In addition, we found plasma NT-proBNP concentrations in patients with ICP>15 mm Hg were significantly higher than those in patients with ICP≤15 mm Hg (p<0.01).
  
  
  CONCLUSIONS
  This study provides evidence that BNP plasma concentrations increase rapidly after TBI. Plasma BNP concentrations are correlated with hyponatremia in severe TBI patients but not in mild and moderate TBI patients. Furthermore, patients with elevated ICP have a higher serum BNP level in first 4 days after injury.
authors.affiliation: Department of Neurosurgery, Huashan Hospital, Fudan University, Shanghai, China.
authors.forename: Xing
authors.initials: X
authors.lastname: Wu
authors.forename: Hongying
authors.initials: H
authors.lastname: Sha
authors.forename: Yirui
authors.initials: Y
authors.lastname: Sun
authors.forename: Liang
authors.initials: L
authors.lastname: Gao
authors.forename: Hua
authors.initials: H
authors.lastname: Liu
authors.forename: Qiang
authors.initials: Q
authors.lastname: Yuan
authors.forename: Tao
authors.initials: T
authors.lastname: Zhang
authors.forename: Jianhong
authors.initials: J
authors.lastname: Zhu
authors.forename: Liangfu
authors.initials: L
authors.lastname: Zhou
authors.forename: Jin
authors.initials: J
authors.lastname: Hu
mesh_terms: D001930:Brain Injuries / Q000097:blood* / Q000150:complications / Q000503:physiopathology; D005260:Female; D006801:Humans; D007010:Hyponatremia / Q000097:blood / Q000209:etiology / Q000503:physiopathology; D019586:Intracranial Hypertension / Q000097:blood / Q000209:etiology / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D020097:Natriuretic Peptide, Brain / Q000097:blood* / Q000502:physiology; D010446:Peptide Fragments / Q000097:blood* / Q000502:physiology; D011446:Prospective Studies; D013997:Time Factors
chemical_list: D010446:Peptide Fragments; C109794:pro-brain natriuretic peptide (1-76); D020097:Natriuretic Peptide, Brain