Cevallos-Naranjo et al. (2026)
Abstract
Background: Malignant hyperthermia is a potentially fatal pharmacogenetic hypermetabolic crisis
triggered by volatile anesthetics and the depolarizing neuromuscular blocker succinylcholine in
susceptible individuals. Early manifestations may include hypercapnia, tachycardia, muscle
rigidity, or masseter spasm; hyperthermia is not invariably the first sign. Objective: To synthesize
clinical evidence on the relationship between succinylcholine exposure during general anesthesia
and the occurrence, phenotype, timing, complications, and mortality of malignant hyperthermia.
Methods: A systematic review was conducted according to PRISMA 2020. MEDLINE/PubMed,
PubMed Central/Europe PMC, and reference lists were searched through July 27, 2026. Human
primary studies reporting malignant hyperthermia events and succinylcholine exposure, either
alone or combined with volatile anesthetics, were included. Narrative synthesis was used
because of clinical and methodological heterogeneity and registry overlap. Results: Twelve
studies were included. A registry-based estimate found a relative risk of 19.6 for malignant
hyperthermia with versus without succinylcholine; when restricted to volatile anesthetics, the
relative risk was 9.1. In a Canadian cohort of 129 confirmed susceptible probands, 15.5% of index
reactions were attributed to succinylcholine alone; another multicenter analysis identified 24
crises after succinylcholine without volatile anesthetics. Co-administration shortened onset time,
and pediatric exposure was associated with more masseter spasm, rigidity, and dark urine.
Delayed dantrolene and inadequate temperature monitoring were associated with complications
and death. Conclusions: Succinylcholine is a clinically important malignant hyperthermia trigger
and may precipitate crises in the absence of volatile anesthetics, although most series include
combined exposure. Treatment should begin promptly when unexplained hypercapnia,
tachycardia, rigidity, or masseter spasm occurs after administration, without waiting for fever.
Dantrolene should be immediately available wherever succinylcholine is used.
Keywords: malignant hyperthermia; succinylcholine; suxamethonium; general anesthesia;
dantrolene; PRISMA 2020.
es contracción muscular sostenida,
1. Introducción
consumo acelerado de oxígeno y
adenosín trifosfato, producción
excesiva de dióxido de carbono y
calor, acidosis, rabdomiólisis,
La hipertermia maligna (HM) es un
síndrome hipermetabólico agudo del
músculo esquelético que aparece en
individuos
genéticamente
hiperpotasemia y riesgo de arritmia o
susceptibles tras la exposición a
determinados fármacos anestésicos.
La alteración funcional del receptor
de rianodina tipo 1 (RYR1), y con
menor frecuencia de CACNA1S u
otros genes relacionados con el
paro cardiaco.13,17,18
Los desencadenantes clásicos son
los
anestésicos
inhalatorios
halogenados y la succinilcolina —
también denominada suxametonio—
,
un bloqueador neuromuscular
acoplamiento
excitación-
despolarizante de inicio ultrarrápido.
Debido a su utilidad para la
intubación de secuencia rápida y el
contracción, provoca una liberación
descontrolada de calcio desde el
retículo sarcoplásmico. El resultado