Biphasic respiratory depression is usually seen after:: (A) Neuroleptanaesthesia, (B) Regional anaesthesia, (C) Halothane anaesthesia, (D) Isoflurane anaesthesia
Answer is A. Neuroleptanaesthesia is produced by droperidol + fentanyl. Fentanyl after IV injection is sequestered by stomach in significant amounts, released into circulation after 3-6 hours and can produce second phase of respiratory depression i.e., biphasic respiratory depression.