Hyponatremia and brain injury: absence of alterations of serum brain natriuretic peptide and vasopressin.
OBJECTIVE
To study any possible relation between hyponatremia following brain injury and the presence of cerebral salt-wasting syndrome (CSWS) or the syndrome of inappropriate secretion of antidiuretic hormone (SIADH), and if vasopressin, brain natriuretic peptide (BNP) and aldosterone have a role in its mechanism.


METHODS
Patients with brain injury admitted to the intensive care unit were included and had their BNP, aldosterone and vasopressin levels dosed on day 7.


RESULTS
Twenty six adult patients were included in the study. Nine (34.6%) had hyponatremia and presented with a negative water balance and higher values of urinary sodium, serum potassium and diuresis than patients with normonatremia. The serum levels of BNP, aldosterone, and vasopressin were normal and no relation was observed between plasma sodium and BNP, aldosterone or vasopressin.


CONCLUSIONS
The most likely cause of hyponatremia was CSWS and there was no correlation between BNP, aldosterone and vasopressin with serum sodium level.
Costa
Karina Nascimento
KN
Intensive Care Unit, Hospital de Base do Distrito Federal, Brasília, DF, Brazil. knc@terra.com.br
Nakamura
Helen Mayumi
HM
Cruz
Leonardo Rodrigues da
LR
Miranda
Lucas Sampaio Valente Fernandes de
LS
Santos-Neto
Rubens Carneiro dos
RC
Cosme
Susyanne de Lavor
Sde L
Casulari
Luiz Augusto
LA
D000293:Adolescent; D000328:Adult; D000450:Aldosterone / Q000097:blood*; D001928:Brain Diseases, Metabolic / Q000097:blood / Q000150:complications / Q000175:diagnosis; D001930:Brain Injuries / Q000097:blood* / Q000150:complications; D005260:Female; D006801:Humans; D007010:Hyponatremia / Q000097:blood* / Q000175:diagnosis / Q000209:etiology; D007177:Inappropriate ADH Syndrome / Q000097:blood / Q000150:complications / Q000175:diagnosis; D008297:Male; D008875:Middle Aged; D020097:Natriuretic Peptide, Brain / Q000097:blood*; D014667:Vasopressins / Q000097:blood*; D055815:Young Adult
D014667:Vasopressins; D020097:Natriuretic Peptide, Brain; D000450:Aldosterone