Succinylcholine apnea

Succinylcholine Apnea and the Cholinesterase Variants Coded for by Genes at the E, Locus... 

Rarely, prolonged apnea may occur in those susceptible because of an inability to adequately metabolize succinylcholine (i.e., increased pseudocholinesterase levels). This condition requires continued positive-pressure ventilation until the patient begins spontaneous respiration. 

Ester hydrolysis Plasma cholinesterase Succinylcholine (neuromuscular blocker) Prolonged apnea... 

Succinylcholine is a neuromuscular blocking agent, which is used clinically to cause muscle relaxation. Its duration of action is short due to rapid metabolism—hydrolysis by cholinesterases (pseudocholinesterase or acylcholine acyl hydrolase)—in the plasma and liver to yield inactive products (Fig. 7.55). Thus, the pharmacological action is terminated by the metabolism. However, in some patients, the effect is excessive, with prolonged muscle relaxation and apnea lasting as long as two hours compared with the normal duration of a few minutes. 

Other hereditary enzyme deficiencies that may result in adverse reactions to certain drugs are comparatively rare, often familial, and of worldwide distribution. Examples of these conditions are pseudocholinesterase deficiencies in certain people who, when given succinylcholine or suxamethonium, develop a profound, general neuromuscular blockade with apnea (38). 

Echothiophate Treatment of open-angle glaucoma when succinylcholine is used as skeletal muscle relaxant during surgery requiring general anesthesia Prolonged apnea... 

Low plasma pseudocholinesterase Succinylcholine Prolonged neuromuscular blockade leading to apnea... 

Birch JH, Foldes FF, Rendell-Baker L. Causes and prevention of prolonged apnea with succinylcholine. Curr Res Anesth Analg 1956 35(6) 609-33. 

Gurman GM. Prolonged apnea after succinylcholine in a case treated with cytostatics for cancer. Anesth Analg 1972 51(5) 761-5. 

Raj et al. (Rl) also reported three unusual cases of prolonged apnea following administration of succinylcholine. The patients had DN values characteristic of the usual phenotype, but had succinylcholine numbers characteristic of the usual-atypical phenotype (Section 6.3.2.1). 

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