Succinylcholine chloride is a short-acting depolarizing neuromuscular blockade that is approved by the United States Food and Drug Administration (FDA) as a provision to other sedatives or hypnotics. It is a correlate of acetylcholine (ACh); hence, it disrupts all cholinergic receptors of the parasympathetic and sympathetic nervous systems. Its use can expedite rapid endotracheal intubation, facilitate surgical procedures, and aid in mechanical ventilation by relaxation of skeletal muscles. Due to its rapid onset and short mechanism of action, it is the drug of choice in emergency situations where immediate airway management is required. The drug's rapid onset allows for quick intervention and control of the airway, and its short duration is advantageous when endotracheal intubation can not be achieved. The skeletal muscle relaxation provided by succinylcholine is beneficial during certain surgical procedures, more specifically, when abdominal wall muscle disruption is necessary, mechanical ventilation is difficult or defied, or in surgical cases where spontaneous respiration of the patient is counterproductive to the current situation.

Malignant hyperthermia is a potentially life-threatening hypermetabolic disorder, often induced by exposure to volatile anesthetics and succinylcholine. There are few reports of malignant hyperthermia during cardiopulmonary bypass. Here the authors review available literature including case reports of malignant hyperthermia and cardiopulmonary bypass and discuss the potential implications of malignant hyperthermia diagnosis and management as it applies to cardiac surgery.

The dystrophinopathies cover a spectrum of X-linked muscle disease ranging from mild to severe that includes Duchenne muscular dystrophy, Becker muscular dystrophy, and DMD-associated dilated cardiomyopathy (DCM). The mild end of the spectrum includes the phenotypes of asymptomatic increase in serum concentration of creatine phosphokinase (CK) and muscle cramps with myoglobinuria. The severe end of the spectrum includes progressive muscle diseases that are classified as Duchenne/Becker muscular dystrophy when skeletal muscle is primarily affected and as DMD-associated dilated cardiomyopathy (DCM) when the heart is primarily affected. Duchenne muscular dystrophy (DMD) usually presents in early childhood with delayed motor milestones including delays in walking independently and standing up from a supine position. Proximal weakness causes a waddling gait and difficulty climbing stairs, running, jumping, and standing up from a squatting position. DMD is rapidly progressive, with affected children being wheelchair dependent by age 12 years. Cardiomyopathy occurs in almost all individuals with DMD after age 18 years. Few survive beyond the third decade, with respiratory complications and progressive cardiomyopathy being common causes of death. Becker muscular dystrophy (BMD) is characterized by later-onset skeletal muscle weakness. With improved diagnostic techniques, it has been recognized that the mild end of the spectrum includes men with onset of symptoms after age 30 years who remain ambulatory even into their 60s. Despite the milder skeletal muscle involvement, heart failure from DCM is a common cause of morbidity and the most common cause of death in BMD. Mean age of death is in the mid-40s. DMD-associated DCM is characterized by left ventricular dilation and congestive heart failure. Females heterozygous for a DMD pathogenic variant are at increased risk for DCM.

Succinylcholine Chloride (SCC), a short-acting neuromuscular relaxant, is non-fluorescent in aqueous solutions. This property makes it impossible to be determined by direct fluorescent method. Naphthalimide dye (NA) exhibits very strong fluorescence emissions in aqueous solution, after complexing with carboxylatopillar[5]arene (CP5A) in aqueous solutions, the fluorescent quenched intensity of complex was observed. On the contraty, stilbazolium dye (SA) exhibits weak fluorescence emissions in aqueous solution, after being included by CP5A, a fluorescence enhancement was observed. However, adding SCC to the NA⊂ CP5A or SA⊂ CP5A complex solution led to the recovery of the fluorescence intensity, in the meantime, the color of SA⊂ CP5A solution changed from dark yellow to light yellow. The competitive supramolecular interaction between SCC, NA and SA for CP5A was studied by spectrofluorometry, 1H NMR. Herein, a FID (fluorescence indicator displacement) system to detect SCC based on NA⊂ CP5A and SA⊂ CP5A complex was developed.

Vecuronium Bromide is an FDA approved peripherally acting muscle relaxant used for general anesthesia, endotracheal intubation, and ICU paralysis to facilitate mechanical ventilation in adequately sedated patients. This nondepolarizing neuromuscular blocking agent is often used as an adjustment to general anesthesia in patients anesthetized with isoflurane and enflurane. It is also used as an adjunct to succinylcholine when performing endotracheal intubation.