Which circuits are suitable for IPPV?

• A. Mini lack, Lac
• B. Magill, Circle
• C. Lac, Magill
• D. Circle, T-piece, Bain, Humphreys

Answer: (D)

Intermittent positive pressure ventilation relies on a circuit that provides a reservoir and an easy, low-resistance path to deliver breaths by hand. The four circuits that fit this are circle, T-piece, Bain, and Humphrey's adapter because each includes a reservoir bag or a compatible arrangement that allows you to deliver controlled, manual breaths while maintaining the flow of anesthetic gases either through rebreathing (circle) or a non-rebreathing setup (the others). This makes them suitable for IPPV.

The Magill and Lack-type circuits don’t offer the same convenient reservoir setup or ventilation pathway for reliable manual breaths, so they’re not as well suited for IPPV.