Delayed high anion gap metabolic acidosis after a suicide attempt: Case report

• Published in: Clinica chimica acta Vol. 436; pp. 329 - 331
• Main Authors: Hsiao, Po-Jen, Chen, Tsu-Yi, Chiu, Chih-Chien, Wu, Tsung-Jui, Chan, Jenq-Shyong, Wu, Chia-Chao, Chen, Jin-Shuen
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 25.09.2014
• Subjects: Acidosis - blood; Acidosis - etiology; Acidosis - metabolism; Aged; Anion gap; Drug poisoning; Female; Humans; Metabolic acidosis; Methanol - blood; Osmolal gap; Rodenticides - poisoning; Suicide; Osmolal gap; Drug poisoning; Anion gap; Metabolic acidosis
• ISSN: 0009-8981; 1873-3492
• DOI: 10.1016/j.cca.2014.06.024

Metabolic acidosis, especially when induced by multiple drug poisoning, often makes rapid and accurate differential diagnosis of the condition challenging. We closely followed anion and osmolal gaps to differentiate among the aetiologies of metabolic acidosis caused by poisoning with unknown drugs. The patient was admitted to our emergency department (ED) in an alert and consciousness state after attempting suicide by ingestion of an uncertain quantity of rodenticides combined with an unknown liquid. Initially, metabolic acidosis (pH7.23) with normal anion gap (12.8) was observed. However, a change in consciousness and hypotension subsequently developed 6h later, combined with severe metabolic acidosis (pH7.16), high anion gap (25.5), and high osmolal gap (83). A presumed diagnosis of methanol intoxication was suspected. After 4h of high-flux haemodialysis (HD), the serum bicarbonate returned to 23mmol/l, and the patient regained consciousness. The serum level of methanol before HD was 193.8mg/dl. The patient was discharged nine days later without sequelae. Delayed high anion gap metabolic acidosis may occur in the ED. Frequent monitoring of anion and osmolal gaps is a feasible method to perform a rapid differential diagnosis, particularly in response to drug poisoning. •Differential diagnosis of multiple drugs intoxication is challenging.•A patient was admitted to the ED after ingesting rodenticide with an unknown liquid.•Normal anion gap metabolic acidosis was found at ED.•After 6h, severe metabolic acidosis, high anion and osmolal gaps were observed.•Anion and osmolal gap are useful tools in differential diagnosis of drug poisoning.