natriuretic-peptide--brain and Intracranial-Hypertension

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).. We measured serum NT-proBNP levels of 84 patients with isolated TBI on a daily basis from day 1 to day 14 after injury.. 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).. 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.

Topics: Brain Injuries; Female; Humans; Hyponatremia; Intracranial Hypertension; Male; Middle Aged; Natriuretic Peptide, Brain; Peptide Fragments; Prospective Studies; Time Factors

Brain natriuretic peptide (BNP) is a potent natriuretic and vasodilator factor which, by its systemic effects, can decrease cerebral blood flow (CBF). In aneurysmal subarchnoid hemorrhage (aSAH), BNP plasma concentrations were found to be associated with hyponatremia and were progressively elevated in patients who eventually developed delayed ischemic deficit secondary to vasospasm. The purpose of the present study was to evaluate trends in BNP plasma concentrations during the acute phase following severe (traumatic brain injury) TBI.. BNP plasma concentration was evaluated in 30 patients with severe isolated head injury (GCS<8 on admission) in four time periods after the injury (period 1: days 1-2; period 2: days 4-5; period 3: days 7-8; period 4: days 10-11). All patients were monitored for ICP during the first week after the injury.. The initial BNP plasma concentrations (42+/-36.9 pg/ml) were 7.3 fold (p<0.01) higher in TBI patients as compared to the control group (5.78+/-1.90 pg/ml). BNP plasma concentrations were progressively elevated through days 7-8 after the injury in patients with diffused SAH as compared to patients with mild or no SAH (p<0.001) and in patients with elevated ICP as compared to patients without elevated ICP (p<0.001). Furthermore, trends in BNP plasma concentrations were significantly and positively associated with poor outcome.. BNP plasma concentrations are elevated shortly after head injury and are continuously elevated during the acute phase in patients with more extensive SAH and in those with elevated ICP, and correlate with poor outcomes. Further studies should be undertaken to evaluate the role of BNP in TBI pathophysiology.

Topics: Adolescent; Adult; Brain Injuries; Female; Follow-Up Studies; Glasgow Coma Scale; Glasgow Outcome Scale; Humans; Intracranial Hypertension; Male; Middle Aged; Natriuretic Peptide, Brain; Time Factors; Treatment Outcome