Related Experiment Videos
Methemoglobinemia induced by local anesthetics
American Journal of Hospital Pharmacy
|January 1, 1981
Summary
Topical local anesthetics like benzocaine can cause methemoglobinemia, a condition where blood can't deliver oxygen. Prompt treatment with methylene blue is effective in reversing this dangerous side effect.
Area of Science:
- Anesthesiology
- Hematology
- Toxicology
Background:
- Topical local anesthetics are widely used for procedures requiring airway anesthesia.
- Benzocaine, a common ingredient in these agents, has been linked to methemoglobinemia.
Observation:
- A patient developed cyanosis and respiratory distress after topical anesthetic use during intubation.
- Blood analysis revealed significantly elevated methemoglobin levels (29 d/dl).
Findings:
- Methemoglobinemia was confirmed as secondary to topical anesthetic agents (Cetacaine and Americaine).
- Intravenous methylene blue administration rapidly resolved the cyanosis and normalized methemoglobin levels.
- Recurrence of cyanosis upon reintubation with different local anesthetics (lidocaine and benzocaine) further supported the diagnosis.
Implications:
- Methemoglobinemia should be considered in patients presenting with cyanosis after topical local anesthetic application.
- Methylene blue is an effective antidote for anesthetic-induced methemoglobinemia.
- Awareness of this adverse effect is crucial for safe anesthetic practice.