A Jackson-Rees modification of the Mapleson E system is chosen for a spontaneously breathing infant undergoing short surgery. Compared with the classic Ayre's T piece, the key addition in this modification is:
- A An adjustable pressure limiting valve on the expiratory limb
- B A second coaxial fresh gas tube inside the corrugated limb
- C An open-ended reservoir bag attached to the expiratory limb ✓
- D A carbon dioxide absorber canister in the circuit
Correct answer: C. An open-ended reservoir bag attached to the expiratory limb
Explanation
The Jackson-Rees modification adds an open-ended (double-ended) reservoir bag to the expiratory limb of Ayre's T piece. This provides a visual monitor of spontaneous breathing, allows controlled ventilation by squeezing the bag, and permits apnoeic oxygenation with continuous positive pressure if needed. It adds negligible resistance because the bag end remains open. Adjustable pressure limiting valves are features of Mapleson A to D systems, and absorber canisters belong to circle systems, not T piece circuits.
Reference: Morgan and Mikhail's Clinical Anesthesiology, 5th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.