Physiologically driven, altitude-adaptive model for the interpretation of pediatric oxygen saturation at altitudes above 2,000 m a.s.l.

摘要

Measuring peripheral oxygen saturation (SpO(2)) with pulse oximeters at the point of care is widely established. However, since SpO(2) is dependent on ambient atmospheric pressure, the distribution of SpO(2) values in populations living above 2000 m a.s.l. is largely unknown. Here, we propose and evaluate a computer model to predict SpO(2) values for pediatric permanent residents living between 0 and 4,000 m a.s.l. Based on a sensitivity analysis of oxygen transport parameters, we created an altitude-adaptive SpO(2) model that takes physiological adaptation of permanent residents into account. From this model, we derived an altitude-adaptive abnormal SpO(2) threshold using patient parameters from literature. We compared the obtained model and threshold against a previously proposed threshold derived statistically from data and two empirical data sets independently recorded from Peruvian children living at altitudes up to 4,100 m a.s.l. Our model followed the trends of empirical data, with the empirical data having a narrower healthy SpO(2) range below 2,000 m a.s.l. but the medians never differed more than 2.3% across all altitudes. Our threshold estimated abnormal SpO(2) in only 17 out of 5,981 (0.3%) healthy recordings, whereas the statistical threshold returned 95 (1.6%) recordings outside the healthy range. The strength of our parametrized model is that it is rooted in physiology-derived equations and enables customization. Furthermore, as it provides a reference SpO(2), it could assist practitioners in interpreting SpO(2) values for diagnosis, prognosis, and oxygen administration at higher altitudes.