The Science Journal of the American Association for Respiratory Care

2008 OPEN FORUM Abstracts

INCREASED CIRCUIT PRESSURES WITH A HIGH FLOW NASAL CANNULA SYSTEM

Jenni Raake1,3, Scott Pettinichi1, Brandy Seger1,2, Rick Amato1,4, James Johnson1, Susan Poynter1



Background: High Flow Nasal Cannula therapy is growing in practice, especially in neonatal and pediatric patients. The voluntary recall by Vapotherm (Vapotherm, Stevensville, MD) created a need for replacement high flow nasal cannula systems which various manufacturers have met. After successful use of one such system, we began experiencing equipment related issues which we suspected were caused by excessive pressures. We studied the system we were using to determine if the pressure was excessively high within the circuit.

Methods:
We used an RT 202 Adult High Flow Circuit (Fisher & Paykel, Irvine, CA) with a Salter Labs (Arvin, CA) adult high flow nasal cannula. Pressure measurements were obtained proximal to humidification chamber and distally to the end of the circuit (at the base of the nasal cannula) using a Criterion Pressure Monitor (Respironics, Inc, Murrysville, PA). With the circuit as packaged and with the addition of a pressure pop off.

Results:
Proximal pressure measurements without a pressure pop off ranged from 4 - 99 cm H2O with flow rates from 3 lpm up to 15 lpm and above, and distal pressures up to 80 cm H2O. The addition of a pop off result in proximal pressures ranging from 4 - 39 cm H2O, and distal pressures of up to 28 cm H2O.

Conclusions:
Significant pressures were noted which created a back pressure in the high flow cannula circuit. Pressures significantly increased at higher flow rates. The addition of a pressure pop off greatly reduced the pressure with the circuit and should be added to improve patient safety