Is Admission Serum Sodium Concentration a Clinical Predictor for the Outcome of Therapy in Critically Ill Poisoned Patients?

BACKGROUND Disorders of serum sodium concentration are some of the most electrolyte abnormalities in the intensive care unit (ICU) patients. These disorders adversely affect the function of vital organs and are associated with increased hospital mortality. PURPOSE In the present study we aimed to evaluate the effects of serum sodium concentration abnormalities at the time of hospital admission on the clinical outcome of therapy in a cohort of critically ill poisoned patients. METHODS In this cross-sectional study, 184 critically ill poisoned patients aged >18 years and in the first 8 hours of their poisoning, hospitalized in the ICU of a tertiary care university hospital (Isfahan, Iran) between 2010-2012, were evaluated at the admission time and 24 hours later for serum sodium concentration abnormalities and its relationship with age, gender, consciousness status, ingested drugs and clinical outcome of therapy. The clinical outcome was considered as recovery and mortality. Logistic Regression analysis was performed for predictive variables including serum sodium concentration abnormalities in patients' clinical outcome. FINDINGS On admission, 152 patients (82.6%) were eunatremic, 21 patients (11.4%) were hyponatremic and 11 patients (6%) were hypernatremic. In the second day eunatremia, hyponatremia and hypernatremia was observed in 84.4%, 13% and 2.2% respectively. Age (OR=1.92; CI=1.18-3.12) and severity of toxicity (OR=1.32; CI=1.12-2.41) were predicting factors of mortality in ICU poisoning patients. CONCLUSIONS Serum sodium concentration abnormalities are prevalent in critically ill poisoned patient but do not seem to have a predictive value for the clinical outcome of therapy.