Comparison of prophylactic effects of diclofenac vs ibuprofen on succinylcholine induced myalgia in precurarized patients. Randomized, controlled, double blinded study

Succinylcholine is a depolarizing neuromuscular blocking agent that causes skeletal muscle relaxation for a very short period. The onset of action of this drug is very quick and quality of muscle relaxation is usually excellent. The drug is used to achieve muscle relation for tracheal intubation and short surgical procedures.

Although it provides an excellent relaxation but its use is associated with various side effects like rise in serum potassium levels, fasciculations of muscle fibers and post operative myalgia. The incidence of postoperative myalgia due to succinylcholine varies, being as high as 90% and generally thought to be approximately 50%.[1][2]

Fasciculations of muscle fibers is due to uncoordinated contractions of muscle fibers that may result in post operative myalgia. The mechanism of postoperative myalgia has not completely been elucidated. It has been proposed that the pain occurs due to muscle damage produced by shearing forces associated with the fasciculations at the onset of block.[2] Studies have shown the possible development of microdamage at the muscle fibres.[3]

Many studies have shown rise in serum creatine kinase that might be because of some degree of trauma of muscle fibers because of fasciculations.[4]

Post operative myalgia is distressing to the patient therefore it is essential to control fasciculations and post operative myalgia following use of succinylcholine.

Various drugs and techniques has been employed to control succinylcholine induced fasciculations and postoperative myalgia like precurarization with nondepolarizing muscle relaxants, self-taming with succinylcholine itself, preoperative stretching exercises[5], magnesium sulfate[6], calcium gluconate[7], benzodiazepines[8] and nonsteroidal anti-inflammatory drugs like diclofenac sodium[9] etc. For precurarization gallamin, atracurium[10], pancuronium and rocuronium[11] have been used in very small doses with variable results.

Recently diclofenac sodium has been used by Tirkey et al (2022) to control succinylcholine induced myalgia.[9]

Intravenous preparation of ibuprofen another nonsteroidal anti-inflammatory drug has been made available recently for clinical use but it has not been used to assess its effects on succinylcholine induced fasciculations and postoperative myalgia.

In the present study the effect of intravenous diclofenac sodium and ibuprofen will be assessed and compared on fasciculations and post operative myalgia in precurarized patients requiring endotracheal intubation for general anesthesia.