Ans. b (Halothane). (Ref. Lee's synopsis of Anesthesia 12th ed. 163)Ether may cause a transient depression of liver function but does not cause significant damage.HALOTHANE# Dose: 0.5% (MAC 0.75%)# Actions: analgesic, anaesthetic# Advantages:- Potent and effective,- Allows for high FI02 delivery,- Bronchodilatation,- Low irritant,- Nice smell; can be used for induction# Disadvantages:- CVS depression,- Cerebral Vasodilatation- | ICP,- Respiratory depression, Airway irritation,- "halothane hepatitis",- Arrhythmias,- Myocardial depression,- Incidence of malignant hyperpyrexiaISOFLURANE# An isomer of enflurane.# It is a stable agent, so, no need of preservative.# It does not depress myocardium, so good for cardiac surgery.# Sensitizes heart to catecholamines, but not nephro/hepatotoxic.# Commonly used in neurosurgery.# Can cause coronary-steal syndrome.ENFLURANE# Nonirritating and noninflammable Liquid# Stimulates salivary and respiratory secretions slightly# Heart rate decreases little and reduction of cardiac output is less marked.# Does not sensitize the heart to adrenaline, arrhythmias are rare.# Bronchodilatation is similar to halothane.# It is a better skeletal muscle relaxant.# Contraindicated in epilepsy.METHOXYFLURANE# It has highest amount of fluoride content.# It can be converted into oxalate in the liver and can cause oxalate renal stone formation.# It is nephrotoxic and causes high out put renal failure.# Not used commonly.SEVOFLURANE# Induction and emergence from anaesthetic are fast and rapid changes in depth can be achieved.# Acceptability is good by pediatric patients.# Sevoflurane does not cause sympathetic stimulation and airway irritation even during rapid induction. Amount of fluoride liberated is safe for kidney and liver.# It is degraded by soda lime - not recommended for use in closed circuit.# Sevoflurane has rapid induction (1-2 min) and also emergence from anesthesia is more rapid than Isoflurane, and is comparable with than seen after continuous Propofol anesthesia. This makes it suitable for day -stay surgery.DESFLURANE# Anaesthetic for out patient surgery.# Induction and recovery are very fast.# Postanaesthetic cognitive and motor impairment is short-lived.# Desflurane is less potent than isoflurane; may induce coughing, breath holding and laryngospasm.# Desflurane can serve as a good alternative to isoflurane for routine surgery.