Routine biological tests in self-poisoning patients: results from an observational prospective multicenter study

Abstract

ContextRoutine biological tests are frequently ordered in self-poisoning patients, but their clinical relevance is poorly studied. Materials and methodsThis is a prospective multicentric observational study conducted in the emergency departments and intensive care units of 5 university and nonuniversity French hospitals. Adult self-poisoning patients without severely altered vital status on admission were prospectively included. ResultsRoutine biological test (serum electrolytes and creatinine, liver enzymes, bilirubin, blood cell count, prothrombin time) ordering and results were analyzed. A total of 1027 patients were enrolled (age, 40.2 ± 14 years; women, 61.5%); no patient died during the hospital stay. Benzodiazepine was suspected in more than 70% of cases; 65% (range, 48%-80%) of patients had at least 1 routine biological test performed. At least 1 abnormal test was registered in 23% of these patients. Three factors were associated with abnormal test results: age older than 40 years, male sex, and poisoning with a drug known to alter routine tests (ie, acetaminophen, NSAIDs, metformine, lithium). Depending on these factors, abnormal results ranged from 14% to 48%. Unexpected severe life-threatening conditions were recorded in 6 patients. Only 3 patients were referred to the intensive care unit solely because of abnormal test results. ConclusionRoutine biological tests are commonly prescribed in nonsevere self-poisoning patients. Abnormal results are frequent but their relevance at bedside remains limited.