The Science Journal of the American Association for Respiratory Care

2012 OPEN FORUM Abstracts


Jeanette M. Merrill-Henry1,2, Micheal H. Terry1,2, Michael Tiras2, Douglas Deming3,4; 1Respiratory Care, Loma Linda University Medical Center, Loma Linda, CA; 2Respiratory Care, Loma Linda Unversity Children’s Hospital, Loma Linda, CA; 3Department of Pediatrics, Loma Linda University Children’s Hospital, Loma Linda, CA; 4School of Medicine, Loma Linda University, Loma Linda, CA

Background: Neonatal Intensive Care Units often discharge patients to living environments where the elevation may be higher than that of the hospital. While newborns may maintain normal SPO2 in the hospital setting, there is no guarantee that level will be sustained at an increased elevation. Neonates that fail to oxygenate well are at risk for hypoxemia, tachypnea, increased work of breathing, tachycardia, and bradycardia, leading to respiratory failure. To insure that newborns being discharged, or traveling to an increased elevation, do not experience hypoxemia and its adverse side effects, we developed a method for performing High Altitude Simulation Testing (HAST) to assess a newborn’s response to changes in elevation prior to discharge. We sought to answer two fundamental questions. Did the HAST alter discharge plans? Was there a correlation between discharge elevation and oxygen dose? Method: Patients were referred for testing by their attending neonatologist and generally met the pre-testing requirements of being born at 37 weeks gestation or younger, with a planned discharge or travel to an elevation = 4000 feet. Infants were placed into a sub-ambient O2 environment to simulate the expected PIO2 at a specified elevation. We collected target elevation, pre and post test oxygen requirements, test outcome and its effect on discharge planning. We examined the correlation between oxygen dose and discharge elevation using the Microsoft Excel function CORREL. Results: We examined the results and conditions of all HAST studies performed for Loma Linda University Children’s Hospital between July 1, 2010 and December 31, 2011 (n=80). As a direct result of these HAST studies, the discharge plan changed for 50% of the patients tested (n=40). Of the eighty tests conducted, 64 (80%) began with an FIO2 of 0.21 and 16 (20%) began with an FIO2 greater than 0.21. Of the patients beginning the test with an FIO2 =0.21, 28 (43.8%) required oxygen to maintain target SPO2 at simulated elevation. The patients beginning the test with FIO2 >0.21, 12 (75%) had an increased oxygen requirement at elevation. For the patients requiring oxygen at discharge we did not observe a correlation between discharge elevation and O2 dose, R=0.017. Conclusion: High altitude simulation testing altered discharge oxygen dose. There was no correlation between elevation and O2 dose requirement in this population. Sponsored Research - None