Acid-base disturbances in acute poisoning and their association with survival.

PURPOSE: The purpose was to investigate the association between acid-base disturbances and mortality in acute poisoning.

MATERIALS AND METHODS: We performed a retrospective cross-sectional exploratory study on all acutely poisoned patients older than 12 years who had been admitted to the main tertiary toxicology hospital in Tehran between March and August 2010.

RESULTS: Of a total of 1167 patients (median age=25 years, 50.9% male), 98 died (74.5% male). Psychotropic medications were the most common cause of poisoning (36.5%), whereas narcotics and psychodysleptics were the most common cause of death (23.5%). Mixed respiratory alkalosis and metabolic acidosis with normal pH were the most common acid-base status (333, 28.5%). However, patients with primary metabolic acidosis and respiratory compensation had significantly higher mortality (31 cases, 18.8%). Logistic regression analysis identified age (odds ratio [OR], 1.051; 95% confidence interval [CI], 1.031-1.070; P<.001), intensive care unit admission (OR, 12.405; 95% CI, 7.178-21.440; P<.001), consciousness level (OR, 1.752; 95% CI, 1.301-2.359; P<.001), hospitalization period (OR, 1.1361; 95% CI, 1.079-1.195; P<.001), severe metabolic acidosis (OR, 6.016; 95% CI, 1.647-21.968; P=.007), and primary respiratory alkalosis (OR, 5.579; 95% CI, 1.353-23.001; P=.017) as death predictors during hospitalization (P<.001).

CONCLUSION: On-arrival acid-base status predicts survival and can be used in prognostication of the poisoned patients.