Malignant hyperthermia (MH) is an important disorder for pediatric ophthalmologists because of its association with strabismus, myopathies, ptosis, and musculoskeletal abnormalities. MH is a defect of calcium binding by the sarcoplasmic reticulum of skeletal muscle that can occur sporadically or be dominantly inherited with incomplete penetrance. When MH is triggered by inhalational anesthetics or the muscle relaxant succinylcholine, unbound intracellular calcium concentration increases. This stimulates muscle contracture, causing massive acidosis. In its fully developed form, MH is characterized by extreme heat production, resulting from the hypermetabolic state.
MH can be fatal if diagnosis and treatment are delayed. The earliest sign is unexplained elevation of end-tidal carbon dioxide concentration. As soon as the diagnosis is made, surgery should be terminated, even if incomplete. Treatment is in the province of the anesthesiologist. See also BCSC Section 1, Update on General Medicine.
Excerpted from BCSC 2020-2021 series: Section 10 - Glaucoma. For more information and to purchase the entire series, please visit https://www.aao.org/bcsc.