Most potent analgesic agent among following:

Ans. a. Nitrous oxide (Ref: Wiley and Churchill-Davidson A Practice of Anesthesia 7/e p536; Miller 7/e p813)Out of the above options, most potent analgesic agent is Nitrous oxide."Nitrous oxide- 50:50 nitrous oxide and oxygen has revolutionized it as analgesic agent; it has been used as an analgesic agent in obstetric surgeries: dental procedures; in acute trauma; burn dressings and cardiac pain as well."- Wiley and Churehill-Davidson A Practice of Anesthesia 7/e p536Miller says "Nitrous oxide produce analgesia that is in part because of release of proenkephalin derived family of endogenous opioids."Physical properties of N2OIt is colourless, non-irritating and sweet smellingBoiling point is -89degCQ.Critical temperature is 36.5degCQ which is above room temperature, therefore it can be kept in liquefied state.Stored as liquid in blue color cylindersQ35 times more soluble than nitrogenQRemember: Anesthesia withNo analgesia* HalothaneQOnly analgesia* N2OQProfound analgesia* KetamineQBest/maximum analgesia* TrileneQ