10 - succinyl choline or suxamethonium mcqs

1q: which muscle relaxant increases intracranial pressure ?

a. mivacurium
b. atracurium
c. suxamethonium
d. vecuronium

answer c. suxamethonium also called succinyl choline

-- succinyl choline or suxamethonium causes increases in

1.intracranial pressure, 2.intraocular pressure, 3.intragastric pressure . this question was asked in AIIMS November 2002 paper .

2q: the use of succinyl choline is not contraindicated in ?

a. tetanus
b. closed head injury
c. cerebral stroke
d. hepatic failure

answer d. hepatic failure

 succinyl choline is short acting muscle relaxant as it is rapidly metabolized by pseudocholinesterase secreted both by liver and plasma . in liver failure this enzyme is reduced ,so succinyl choline concentration is increased during liver failure and is also maintained for greater periods .
 but this does not mean that succinyl choline should be contraindicated in liver failure. The duration of paralysis produced by succinyl choline is increased during liver failure but this does not require succinyl choline to be contraindicated in liver failure .

conditions where succinyl choline use is contraindicated due to hyperkalemia caused by succinyl choline are :

1. tetanus
2. stroke
3. closed head injury
4. myopathy
5. burns
6. acidosis
7. massive trauma
8. prolonged body immobilization
9. guillian barre syndrome
10. spinal cord injury
11. paraplegia
12. severe intraabdominal infection

-- this question was also asked in AIIMS November 2002 paper .

3q: a six year old boy is scheduled for examination of the eye under anaesthesia. The father informed that for the past six months , the child is developing progressive weakness of both legs. His elder sibling had died at age of 14 years. Which drug would you definitely avoid during the anaesthetic management ?

 

1. succinyl choline
2. thiopentone
3. nitrous oxide
4. vecuronium

answer a. succinyl choline

-- weakness of the legs indicate that the boy is suffering from myopathy ( most probably duchenes muscular dystrophy ). Succinyl choline is contraindicated in myopathy due to increased risk of hyperkalemia .

-- this question was also asked in the november 2002 AIIMS paper .