Which intravenous anesthetic is commonly used for rapid induction and may be given as a bolus or continuous rate infusion?

• A. Ketamine
• B. Thiopental
• C. Etomidate
• D. Propofol

Answer: (D)

Propofol is an ultra-short-acting intravenous anesthetic chosen for rapid induction because it produces hypnosis within seconds and wears off quickly as it redistributes and is metabolized. This rapid onset and short duration make it ideal for giving as a bolus to quickly induce anesthesia and then using a continuous rate infusion to maintain anesthesia without prolonged recovery. It doesn’t provide much pain relief on its own, so analgesia is often added with other drugs.

Ketamine can provide analgesia and maintains airway reflexes, but its induction is less smooth and recovery can be dissociative or irregular, so it isn’t as ideal for a straightforward rapid induction with a clean, maintainable course. Thiopental induces anesthesia quickly but can cause apnea and a less predictable, longer recovery, and isn’t as suitable for ongoing infusion. Etomidate preserves cardiovascular stability and has minimal respiratory depression, but its use is limited by possible adrenal suppression and other side effects, making it less common for routine bolus-plus-infusion maintenance.