This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Anaesthesia
Thiopentone is contraindicated in ? 
Select and explain. 
A. Acute intermittant porphyria, B. Electro convulsive therapy, C. Sarcoidosis, D. Diabetic patients
A: Acute intermittant porphyria
Answer: A: Acute intermittant porphyria 
Explanation: Ans. is 'a' i.e., Acute intermittant porphyria Thiopentone It is an ultrasho acting barbiturate. It has sho duration of action due to rapid redistribution. It causes fall in BP due to vasodilatation - Cardiovascular collapse may occur if hypovolemia, shock or sepsis are present. It can cause respiratory depression. It has anticonvulsant action - agent of choice for neurosurgical procedures. It is the agent of choice for cerebral protection. because it decreases ICT, and cerebral metabolic rate. Miller 6th/e - 330, 332 .o It is poor analgesic -f painful procedure should not be done.It produces hyperalgesia. It has poor muscle relaxant propey. Extravasation of the solution or inadverent intraerial injection produces intense pain - thrombosis and vasoconstriction can cause necrosis and gangrene. Treatment of this condition includes. Leaving needle insitu Brachial block Heparin injection to - prevent thrombosis Dilution of thiopentol t by injection of saline into the aery. Papaverine injection - to relieve spasm. Urokinase, streptokinase, vasodilators, steroid and lignocaine can also be used. Contraindications Acute intermittant porphyria Cardiovascular instability or shock. Respiratory obstruction No availibility of airway equipments. Status asthmaticus