(b) When the patient exhales, he directs the gas, via the other
breathing tube, to the exhalation check valve. The exhalation check valve opens, the
breathing bag expands, and the inhalation check valve closes. When the patient
inhales, the exhalation check valve closes, the breathing bag contracts, and the
inhalation check valve opens.
(c) Gas flowing through the exhalation valve enters the absorber and
flows downward through the soda lime canisters. The soda lime absorbs the carbon
dioxide (CO2) from the exhaled mixture. The remaining gases recycle out of the
absorber to the inhalation check valve to rejoin the fresh gas flow. The cycle then
(d) There are two relief valves within the breathing circuit: the gas
evacuator/relief valve and the nonadjustable pressure relief valve. If the gases within
the breathing circuit exceed an established pressure, these valves release excess gas
to the atmosphere.
c. The Breathing Circuits: Pediatric Partial Re-breathing Circuit. Refer to
(1) Pediatric partial re-breathing circuit components. The pediatric partial
re-breathing circuit consists of the following items and components:
(a) The pediatric supply tube with connector and TEE.
(b) The short corrugated breathing tube with connectors.
The small (1 liter) breathing bag with the scavenging valve.
(d) The patient connections (elbow and mask).
Pediatric partial re-breathing circuit flow.
(a) The adjusted total flow of gases from the vaporizer travels through
the pediatric supply tube to the TEE connector. The gas takes two directions at the tee
connector flowing to the patient and to the small breathing bag.
(b) Gas which the patient has exhaled flows to the small breathing bag
along with whatever fresh gas was not inhaled.