Non-Rebreathing System Used for patients weighing: <15 pounds Some clinics may use a rebreather for patients as small as 6 pounds Less than 6 pounds: non-rebreather is a MUST There are many types: we will be discussing the Jackson-Rees (in detail) and the Bain coaxial

Non-Rebreathing System Attach a clear, long, plastic hose to the fresh gas outlet (this tube comes from the vaporizer outlet port) Flow of gas differs from rebreathing circuit now!! Fresh gas goes directly to the patient Not through the unidirectional valves! The same gas exchange happens in the patient…

Non-Rebreathing System Exhaled gas comes directly out through a separate hose. This plastic hose is corrugated, short and much wider. Gas now flows through the pop-off and then either into a reservoir bag OR scavenging hose. WAG are scavenged the same way as a rebreather

What’s Missing Here?? What parts on the rebreathing system are missing from the non-rebreathing system? 1. 2. 3. How do we compensate for this? CO2 canister, flutter valves, pressure manometer; high O2 flow rates and extra careful when PPV

Non-Rebreathing System Benefits: 1. Less parts = less ________________ Smaller animals need this feature! 2. Quicker changes in Ax depth Disadvantages: 1. Higher amount of oxygen used due to patient not-rebreathing any gas 2. Patient is only breathing cold, dry fresh gas What can we do about this? Resistance Warm the inspiratory tube

Non-Rebreathing Systems Jackson-Rees Norman Mask Elbow

Non-rebreathing Systems Bain coaxial Tube within a tube- helps with warming http://asevet.com/resources/circuits/index.htm

Universal Bain Block Has a pressure manometer!

Oxygen Flow Rate Non-rebreathing system: High b/c removal of CO2 is dependent on flow in the system Can go up to 600 ml/kg/min! Note: An inadequate fresh gas supply will result in your patient re-breathing gases…remember, there is no CO2 absorber! 300 ml/kg/min

Non-rebreathing Oxygen Flow Rate Practice problem: Patient weighs 4.65 kg How many ml/min of oxygen does the patient need? Flow rates need to be in L/min:

Leak Testing (Both Breathing Circuits) Performed before every anesthesia to check the system for leaks The last thing you do on your anesthetic machine *Hint: this will also tell you if your machine is hooked up correctly Top three most common leaky parts: 1. 2. 3. Fresh gas inlet not connected, CO2 canister misaligned, reservoir bag damaged

Leak Testing – Low Pressure Test Steps: close pop-off valve AND cover end of breathing tube with something Turn on flow meter to 2 L/min and let oxygen fill reservoir bag Once full, turn down the O2 to 0.2 L/min Gently squeeze the bag and listen/feel for leaks If none, maintain a full bag for: __________ at _______________. If the bag doesn’t hold pressure (remain full), you have a leak! 30 psi for 30 seconds

Things to Consider Which breathing system may help keep a patient from becoming hypothermic? Which rebreathing circuit provides the least resistance to the patient? Which breathing system is more costly to use? Which breathing system allows for the quickest change in anesthetic depth? Any coaxial Circle with y piece Non-rebreather