Related Experiment Video
Updated: Jun 11, 2026

Inducing Post-Traumatic Epilepsy in a Mouse Model of Repetitive Diffuse Traumatic Brain Injury
Published on: February 10, 2020
Prolonged apnea after small single dose of intravenous tramadol
Ravindra Pandey1, Lenin B Elakkumanan, Rakesh Garg
1Department of Anaesthesiology and Intensive Care, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, India.
Abstract:
We report an unusual case of respiratory depression and prolonged apnea after a single, 50-mg intravenous dose of tramadol. Shortly after an uneventful surgery and anesthesia, the patient was administered intravenous tramadol. Soon after the tramadol injection, the patient became apneic, did not respond to verbal command, and started exhibiting oxygen desaturation. He was quickly administered 100% oxygen and positive pressure ventilation via a Bain circuit, and it took 45 minutes for the spontaneous respiration to return to regular. The respiratory depression could be due to increased amount of (+)enantiomer in that ampoule of tramadol. Physiological parameters affecting the metabolism of either enantiomer of tramadol or perioperative drugs need to be evaluated, as do physiological changes affecting the activity or metabolism of (+enantiomer. This case report demonstrates that even a small single dose of tramadol administered intravenously in the immediate postoperative period after general anesthesia may manifest as sudden and prolonged apnea.
Related Concept Videos
Opioid Analgesics: Synthetic and Semisynthetic Opioids
Parenteral Anesthetics: Overview
Desensitization and Tachyphylaxis
Several...
Sedatives and Hypnotics Drugs: Miscellaneous Agents
Melatonin congeners like ramelteon (Rozerem) and tasimelteon (Hetlioz) selectively bind to melatonin receptors (MT1 and MT2) and thus mimic the actions of melatonin, a hormone that regulates sleep-wake cycles. Tasimelteon is primarily used for non-24-hour sleep-wake disorder, common in blind patients. They are also used to treat conditions like insomnia...
CNS Depressants: Barbiturates and Benzodiazepines
Stages of General Anesthesia
