Ans. is 'c' i.e., Desflurane o All inhalational agents depress renal function by decreasing the renal blood flow. Direct toxicity is caused by fluorinated compounds due to production of Inorganic fluoride (F ).AgentFluoride level producedo Methoxyflurane50-80 mm (maximum)o Sevoflurane30 - 50 mmo Enflurane20 - 25 mmo Isoflurane4-8 mmo HalothaneProduces only in anaerobic conditionso DesfluraneNil (minimal)o Renal threshold beyond which fluoride levels are toxic is 50 mm. Methoxyflurane is most nephrotoxic -Causes high output (Polyuric) renal failure. Desflurane has no nephrotoxicity.o Sevoflurane & enflurane does not cause renal toxicity in normal person, but should be avoided in renal diseases.