Vasopression serum levels and disorders of sodium and water balance in patients with severe brain injury / Niveis sericos de arginina vasopressina e disturbios de sodio e agua em pacientes com lesão cerebral grave

AUTOR(ES)
DATA DE PUBLICAÇÃO

2006

RESUMO

Background. Disorders of sodium and water balance, especially those secondary to diabetes insipidus (DI), syndrome of inappropriate anti-diuretic hormone (SIADH) and cerebral salt wasting syndrome (CSWS), are frequently seen in patients with severe brain injury (SBI), either traumatic or non-traumatic, and may jeopardize their prognosis. Many authors have suggested that an increase in vasopressin (AVP) secretion may be responsible for the worsening of primary brain lesion as long as it affects the brain mechanisms of edema formation. However, this remains a focus of debate in the literature. Objective. To evaluate vasopressin plasma levels and sodium and water balance disorders in patients with SBI. Design. Prospective, observational, open label study. Setting. General adult intensive care unit, Hospital de Clínicas, Campinas State University. Patients and Methods. Thirty-seven adult patients, both sexes, with SBI (admission Glasgow Coma Scale score ? 8) and an estimated time of injury ? 72 hours were studied. Clinical and laboratory data were recorded and AVP was measured in venous blood samples collected on the 1st, 2nd, 3rd and 5th days following inclusion. Laboratory data from 29 healthy adult volunteers previously reported served as control. Results. Mean AVP serum levels remained inside the normal range in SBI patients, without significant differences in relation to control group, and were proportionally lower at 5th day compared to 1st day following inclusion (1.5 ± 1.6 pg/ml vs 2.3 ± 2.8 pg/ml; p = 0.035). AVP serum levels were slightly higher in patients who died compared to survivors, but this difference was not significant (p = 0.062), and have shown a decrease from the 1st to 5th day of observation in both groups (p = 0.049). Serum sodium and plasma osmolality, and long as their variability, were greater in non-survivor than in survivor patients (p <0.05). Conclusion. AVP plasma levels remained within normal range in SBI patients, and these levels tended to decrease over time, both in survivor and non-survivors. However, serum sodium and plasma osmolality have shown great variations in SBI patients, and non-survivor ones have shown greater and more significant deviations from normal values than those who survived, especially hypernatremia and hyperosmolality, consistent with the presence of posterior hypothalamus-hypophysial axis dysfunction, mainly diabetes insipidus. Nevertheless, these results do not allow us to clearly define whether these disturbances aggravate the primary lesion or if they are merely a reflex of the cerebral injury severity

ASSUNTO(S)

cerebrovascular accident hiponatremia trauma craneocerebral craniocerebral trauma hyponatremia acidente cerebrovascular vasopressina hipernatremia hipernatremia

ACESSO AO ARTIGO

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