Ans. is 'a' i.e., Acute intermittant porphyria o Thiopentone is contraindicated in acute intermittant porphyria.1. Thiopentoneo It is an ultrashort acting barbiturate.o It has short duration of action due to rapid redistribution.o It causes fall in BP due to vasodilatation - Cardiovascular collapse may occur if hypovolemia, shock or sepsis are present.o It can cause respiratory depression.o It has anticonvulsant action - agent of choice for neurosurgical procedures.o It is the agent of choice for cerebral protection. because it decreases ICT, and cerebral metabolic rate. -- Miller 6th/e - 330, 332o It is poor analgesic - painful procedure should not be done.o It produces hyperalgesia.o It has poor muscle relaxant property.o Extravasation of the solution or inadverent intrarterial injection produces intense pain - thrombosis and vasoconstriction can cause necrosis and gangrene.o Treatment of this condition includes.# Leaving needle insitu# Brachial block# Heparin injection - to prevent thrombosis# Dilution of thiopentol by injection of saline into the artery.# Papaverine injection - to relieve spasm.# Urokinase, streptokinase, vasodilators, steroid and lignocaine can also be used.o Contraindications# Acute intermittant porphyria# Respiratory obstruction# Status asthmaticus# Cardiovascular instability or shock.# No availibility of airway equipments.2. Methohexitoneo Another ultrashort acting barbiturateo 3 times more potent than thiopentoneo It induces convulsion (contrast thiopentone is an anticonvulsant) - used for ECT.o Excitment during induction and recovery are more common than thiopentone.