Respiratory depression is LEAST after induction dose of which agent?

Respiratory depression is LEAST after induction dose of which agent?

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

Answer: (B)

The key idea is how different induction agents affect breathing. Ketamine stands out because it is a dissociative anesthetic that tends to maintain spontaneous ventilation and airway reflexes. After an induction dose, patients given ketamine usually continue to breathe on their own with preserved tidal volumes and respiratory drive, so respiratory depression is minimal. In contrast, propofol and methohexital cause dose-dependent respiratory depression and can lead to apnea after induction. Etomidate is relatively stable for ventilation, but apnea can still occur with the injection in some cases. So, among these agents, ketamine produces the least respiratory depression after an induction dose.

The key idea is how different induction agents affect breathing. Ketamine stands out because it is a dissociative anesthetic that tends to maintain spontaneous ventilation and airway reflexes. After an induction dose, patients given ketamine usually continue to breathe on their own with preserved tidal volumes and respiratory drive, so respiratory depression is minimal.

In contrast, propofol and methohexital cause dose-dependent respiratory depression and can lead to apnea after induction. Etomidate is relatively stable for ventilation, but apnea can still occur with the injection in some cases. So, among these agents, ketamine produces the least respiratory depression after an induction dose.