General anesthesia in "inducible" porphyrias

Area of Science:

• Anesthesiology
• Medical Genetics
• Pharmacology

Background:

• Porphyrias are a group of genetic disorders affecting heme synthesis.
• Inducible porphyrias, such as acute intermittent porphyria (AIP) and variegate porphyria (VP), pose risks during anesthesia.
• Assessing anesthetic risks in these patients is crucial for patient safety.

Purpose of the Study:

• To evaluate the risk of inducing acute porphyric symptoms following general anesthesia.
• To determine the safety of specific anesthetic agents, including barbiturates like thiopental, in patients with AIP and VP.

Main Methods:

• Retrospective analysis of 78 anesthesia exposures in 47 patients with AIP and VP.
• Categorization of anesthesia exposures based on patient's symptomatic status (latent vs. acute episode).
• Review of anesthetic agents used, with a focus on barbiturate and thiopental administration.

Main Results:

• No postoperative acute attacks occurred in 37 patients who received anesthesia during latent porphyric stages.
• Anesthesia during acute episodes led to symptom exacerbation in some patients, particularly those receiving thiopental.
• Seven of ten patients receiving thiopental during acute episodes experienced worsened symptoms, compared to two of four who did not receive thiopental.

Conclusions:

• General anesthesia appears to carry a low risk of inducing acute symptoms in patients with latent AIP and VP.
• Thiopental may aggravate porphyric symptoms when administered during an acute episode of AIP or VP.
• Careful consideration of anesthetic agents is warranted for patients with porphyrias, especially during acute exacerbations.