Background: Pulse oximetry, a ubiquitous, noninvasive method to monitor oxygen saturation (SpO2), requires larger, nonportable equipment. Smartphone pulse oximeter applications (apps) provide a portable, cost-effective option, but are untested in children. We hypothesize that smartphone pulse oximetry will not be inferior to standard pulse oximetry measured in healthy children.
Materials and methods: Two main types of pulse oximetry apps, a camera-based app (CBA) that uses a phone camera flash and lens and a probe-based app (PBA) that uses an external plug-in probe, were compared with standard pulse oximetry measured in children ages 2-13 years without a respiratory complaint and a triage SpO2 ≥97% seen in a pediatric Emergency Department. Two investigators obtained heart rate and SpO2 using each app. Inter-rater reliability was tested using interclass correlations (ICCs), and Bland-Altman method was used to compare app values to triage measurements.
Results: Eighty-one patients were enrolled. ICC for SpO2 for PBA and CBA were 0.73 and -0.24, respectively. The 95% limits of agreement between the PBA SpO2 and triage SpO2 were -2.8 to +2.5 compared with -4.1 to +3.5 for the CBA SpO2 and triage SpO2. Mean differences between triage SpO2 and the PBA SpO2 (-0.17%) and triage SpO2 and CBA SpO2 (-0.33%) were not statistically significant.
Discussion and conclusions: Smartphone-based pulse oximetry is not inferior to standard pulse oximetry in pediatric patients without hypoxia. Reliability was superior for PBA compared with CBA, with more precise agreement for the PBA compared with the CBA. Future studies should test pulse oximetry apps in a hypoxic pediatric population.
Keywords: home health monitoring; m-health; pediatrics; technology; telemedicine.