Anesthetics malignant hyperthermia caused

The answer is e. (Kat ung, pp 428-429J Although a rare occurrence, halothane and other inhaled gas anesthetics may cause malignant hyperthermia Apparently, this occurs in genetically susceptible individuals Its onset may be accelerated by the concomitant use of succinylcholine. Immediate treatment includes administration of dantrolene. 

A rare interaction of succinylcholine with volatile anesthetics results in malignant hyperthermia, a condition caused by abnormal release of calcium from stores in skeletal muscle. This condition is treated with dantrolene and is discussed below under Spasmolytic Drugs and in Chapter 16. 

Malignant hyperthermia is a frequently fatal condition that involves severe muscle contraction and hyperthermia. Episodes are triggered by stress and/or specific volatile anesthetics, such as halothane, which cause excessive calcium release from the sarcoplasmic reticulum. The disorder is caused by a mutation in the skeletal muscle ryanodine receptor. The physiological mechanism by which stress triggers malignant hyperthermia is not fully understood. 

Malignant hyperthermia is most likely, given that anesthetic agents stimulate a calcium release channel, leading to excessive Ca + release from the cistemae of the sarcoplasmic reticulum, in turn causing muscle contraction, an increase in body temperature, tachycardia, and subsequent metabolic acidosis. 

Answer D. The pharmacologic action common to both morphine and D-tubocurarine is the release of histamine from mast cells, causing vasodilation. Morphine increases, but D-tubocurarine (via ganglion blockade) decreases, bladder tone. When used in combination with inhalational anesthetics (e.g., halothane), D-tubocurarine has been implicated in malignant hyperthermia. Morphine relaxes the uterus, but D-tubocurarine has no effects on smooth muscle neurotransmission. 

Musck Halothane causes some relaxation of skeletal muscle via its central depressant effects and potentiates the actions of nondepolarizing muscle relaxants (curariform drugs see Chapter 9), increasing both their duration of action and the magnitude of their effect. Halothane and the other halogenated inhalational anesthetics can trigger malignant hyperthermia this syndrome frequently is fatal and is treated by immediate discontinuation of the anesthetic and administration of dantrolene. 

Malignant hyperthermia is an inherited disorder that causes severe hyperthermia, metaboiic acidosis, and rigidity after certain anesthetic agents (most commoniy haiothane and succinyichoiine) are used. 

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