The Science Journal of the American Association for Respiratory Care

2010 OPEN FORUM Abstracts


Kenny Winn; Respiratory Care, Carolinas Medical Center, Charlotte, NC

Background: Traditionally a one-way-valve is necessary for delivery of inhaled Nitric Oxide (iNO) in conjunction with High Frequency Oscillatory Ventilation (HFOV). Conversely, we believe the one-way-valve does not create unidirectional flow during HFOV. We believe the flow is bidirectional through the one-way-valve during HFOV. Accordingly, the one-way-valve may not be necessary when delivering iNO in conjunction with HFOV. This study measures flow and pressure through the one-way-valve during HFOV. Method: 1. Set-up 3100A and 3100B HFOV circuits and place the one-way-valve pre-heater and performed pre-use procedure for both 3100A and 3100B. Connected test lung to 3100A and 3100B circuits. 2. 3100A: Set Bias Flow 10 L/min, Hz 15, DP 18 cmH2O. 3100B: Set Bias Flow 20 L/min, Hz 6, DP 70 cmH2O. 3. Measured change in pressure (DP) in cmH2O pre and post one-way-valve pre-heater for 3100A and 3100B. 4. Measured bias flow (L/min) pre and post one-way-valve for 3100A and 3100B. 5. Removed the one-way-valve and re-performed pre-use procedure for 3100A and 3100B. 6. Repeated measurements from steps 3 and 4. Results: 3100A: Measured DP pre and post one-way-valve: 4 cmH2O. The measured DP without one-way-valve: 4 cmH2O. Bias Flow measured 10 L/min pre and post one-way-valve and 10 L/min without one-way-valve. 3100B: The measured DP pre and post one-way-valve: 6 cmH2O. Measured DP without one-way-valve: 6 cmH2O. Bias Flow measured 20 L/min pre and post one-way-valve and 20 L/min without one-way-valve. Conclusion: These findings propose that the one-way-valve allows for bidirectional flow during HFOV. Hence, the one-way-valve may not be necessary when administering iNO during HFOV. Additionally, measured bias flow was consistent with and without the one-way-valve in both the 3100A and 3100B circuit. Accordingly, iNO injected into the HFOV circuit may be the same with or without the one-way-valve. Discussion: Both HFOV and iNO are technical in nature and entail utmost attention to detail when administering to the critically ill patient. Therefore, when combining these two modalities together it is valuable to eliminate unnecessary technical equipment to facilitate efficient patient care, decrease practitioner anxiety, and most importantly eliminate medical errors that may cause serious harm to the patient. Additional studies to determine necessity of the one-way-valve during HFOV and iNO are necessary. Sponsored Research - None