title: Refractory shock and asystole related to tramadol overdose.
abstract: BACKGROUND
  Tramadol use is largely considered safe. However, several lethal cases of tramadol intoxication were reported, suggesting an underestimated toxicity. We report for a tramadol overdose case in combination with other central nervous system depressants, leading to refractory shock requiring extracorporeal life support.
  
  
  METHODS
  A 33-year-old man was admitted in our intensive care unit for drug intoxication with coma, seizures, and hypotension without signs of heart failure. A few hours later, he developed a ventricular tachycardia, followed by a brief cardiac arrest in asystole with refractory shock requiring an extracorporeal life support, vasopressors, and hemofiltration. With this aggressive support, his overall status gradually improved. Repeated echocardiography showed an improvement in the cardiac function. The patient was weaned off extracorporeal life support on day eight and discharged on day 12. On admission, a urine analysis, using gas chromatography-mass spectrometry, showed high peaks of tramadol and desmethyltramadol with the presence of hydroxyzine, gabapentine, and clonazepam. The tramadol blood concentration measured by the high-performance liquid chromatography method-diode array detector was 23.9 mg/L, much higher than many previously reported fatal overdoses. No other drugs with potential cardiac toxicity, such as beta-blockers, calcium antagonists, antiarrythmic, antidepressants, meprobamate, or other xenobiotics were detected.
  
  
  CONCLUSIONS
  This case illustrates that tramadol overdose may cause refractory shock and asystole when taken in combination with CNS depressants, and reminds all physicians to be vigilant with regard to the potential toxic effects of tramadol.
authors.affiliation: Department of Medical Intensive Care, Caen University Hospital, Caen Cedex, France. daubin-c@chu-caen.fr
authors.forename: Cédric
authors.initials: C
authors.lastname: Daubin
authors.forename: Charlotte
authors.initials: C
authors.lastname: Quentin
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Goullé
authors.forename: Damien
authors.initials: D
authors.lastname: Guillotin
authors.forename: Philippe
authors.initials: P
authors.lastname: Lehoux
authors.forename: Olivier
authors.initials: O
authors.lastname: Lepage
authors.forename: Pierre
authors.initials: P
authors.lastname: Charbonneau
mesh_terms: D000328:Adult; D000701:Analgesics, Opioid / Q000506:poisoning*; D002492:Central Nervous System Depressants / Q000008:administration & dosage / Q000009:adverse effects; D062787:Drug Overdose; D006323:Heart Arrest / Q000139:chemically induced*; D006801:Humans; D008297:Male; D012769:Shock / Q000139:chemically induced*; D014147:Tramadol / Q000008:administration & dosage / Q000506:poisoning*
chemical_list: D000701:Analgesics, Opioid; D002492:Central Nervous System Depressants; D014147:Tramadol