Accidental Intrathecal Morphine Overdose During the Surgery: A Case Report and Literature Review

TL;DR

A patient accidentally received ten times the intended morphine dose during surgery but did not experience any adverse effects, highlighting a unique case in anesthetic management.

Contribution

This case report documents an accidental high-dose morphine administration with no adverse effects, offering insights into anesthetic monitoring and safety.

Findings

A tenfold overdose of intrathecal morphine was administered during surgery.

The patient showed no adverse effects despite the overdose.

A decrease in anesthetic MAC helped identify the dosing error.

Abstract

Neuraxial anesthetic techniques have become part of the multimodal analgesia approach for gynecologic surgeries. Specifically, intrathecal morphine is one of the opioids most commonly used for prolonged pain management postoperatively. However, doses above a certain threshold pose a greater risk of adverse effects, especially respiratory complications. This case highlights the challenges faced during the management of an accidental administration of a tenfold dose of morphine in the subarachnoid space for a patient subjected to major gynecologic surgery. Surprisingly, yet to our advantage, the patient exhibited no evidence of the anticipated adverse effects and no further intervention was required. A key indicator that was crucial in identifying the mistake was a diminution in the minimal alveolar concentration (MAC) of the anesthetic agent used.