<prompt> Inhalational agent of choice for induction of anesthesia in Children?SevofluraneEnfluraneIsofluraneHalothane  <response>: Ans. a Sevoflurane Ref. Anaesthesia by Ajay yadav 3rd ed., p 65SEVOFLURANE Chemistry and Physical Properties- It is nonflammable and nonexplosive in mixtures of air or oxygen.- Care must be taken to ensure that sevoflurane is not used with an anesthesia machine in which the CO2 absorbent has been dried by prolonged gas flow through the absorbent.- Sevoflurane reaction with desiccated CO2 absorbent also can produce CO2 which can result in serious patient injury. Pharmacokinetics- rapid induction of anesthesia, and rapid emergence following discontinuation of administration.- Sevoflurane is metabolized in liver by CYP2E1 predominant product being hexafluoroisopropanol, Clinical Use- Sevoflurane is widely used, particularly for outpatient anesthesia, because of its rapid recovery.- Suited for inhalation induction of anesthesia particularly in children as it is not irritating to airway.- It the most effective clinical bronchodilator of the inhalational anesthetics.- Unlike isoflurane or desflurane, sevoflurane does not produce tachycardia and thus may be a preferable agent in patients prone to myocardial ischemia. Side Effects- Hypotensive effect- Sevoflurane produces effects on cerebral vascular resistance, cerebral metabolic O2 consumption, and cerebral blood flow that are very similar to those produced by isoflurane and desflurane.- Biochemical evidence of transient renal injury has been reported in human volunteers.- It is not known to cause hepatotoxicity.AnestheticSolubilityMAC Metabolism Unique side effectspropertiesNitrous oxide0.51000Low potency; because the MAC is 100, it cannot provide com plete anesthesia; good for induction; good anesthesia and amnesiaDesflurane0.46.50.1Pulmonary irritantSevoflurane0.72.03-Isoflurane1.41.30.2-Enflurane1.81.78ProconsultantHalothane2.30.820Halothane hepatitis; sensitizes heart to arrhythmogenic effects of catecholaminesMethoxyflurane120.270NephrotoxicityOil: gas partition approx. 150 MACEducational point: Fluoride ion liberation - M S E I D. Desflurane is a strong airway irritant, and can cause coughing, breath-holding, laryngospasm, and excessive respiratory secretions. Because of its irritant properties, desflurane is not used for induction of anesthesia. 