<prompt> Muscle relaxant associated with increased ICP is?MivacuriumAtracuriumSuxamethoniumVecuronium  <response>: Ans. is c i.e., Suxamethoneum Sch causes increases in all pressures - intraocular, intracranial, BP, and intrabdominalSuccinylcholine Suxamethonium SCh is a depolarising skeletal muscle relaxant. It causes sustained partial depolarization of muscle end plate - Initially produce twitching and fasciculation followed by flaccid paralysis. It is the shortest and fastest acting skeletal muscle relaxant. It is the only muscle relaxant which stimulate autonomic ganglia and vagus - Bradycardia occurs due to vagal stimulation. SCh is the most commonly used muscle relaxant for passing endotracheal tube rapacuronium and rocuronium are alternatives. SCh is rapidly hydrolysed by plasma cholinersterase, some patients have genetically determined abnormality or deficiency of pseudocholinesterase, in them, SCh causes phase II block dual block. It can cause muscle fasiculations and soreness, change in BP and HR, arrhythmia, histamine release and K effux from muscles. Post-operative muscle pain myalgia, muscle soreness is a very common problem. It can accentuate malignant hyperthermia caused by halothane - Succinylcholine is the most common cause of malignant hyperthermia. Succinylcholine can cause dangerous hyperkalemia in patients with: - Burn Massive trauma Crush injury Severe intra-abdominal infection Spinal cord injury HemiplegiaParaplegia Muscular dystrophy GB syndrome Rhabdomyolysis Severe Parkinsonism Tetanus Polyneuropathy Closed head injury Stroke Encephalitis Mysthenia gravis SCh causes increases in all pressures - intraocular, intracranial, BP, and intrabdominal. SCh can cause Trismus masseter spasm especially in patients susceptible for malignant hyperthermia. 