Resumen: Objective: Heart rate variability (HRV) is a non-invasive measure of the interaction between the autonomic nervous system (ANS) and the cardiovascular system and an indicator of physiologic stress. HRV is proposed as an alternative biomarker to the effect of high flow nasal cannula (HFNC) therapy, a non-invasive ventilation mode, in children with severe respiratory disease. Approach: Seven children with severe acute respiratory disease were included in this pilot study. All of them received HFNC treatment. Standard physiological variables, such as heart rate (HR), breathing rate (BR) and blood oxygen saturation (SpO2) were analyzed during HFNC therapy. HRV, which includes the time domain parameters defined by the mean of RR intervals (avRR), the standard deviation of RR intervals (stdRR), the root mean square of differences between adjacent RR intervals (rmsSD), and the frequency domain parameters defined by spectral powers of low frequency (LF, 0.04 Hz–0.15 Hz) and high frequency (HF, 0.15 Hz–0.4 Hz) bands was also analysed during therapy. Main results: Only the time domain parameter rmsSD showed a significant increase (from 0.03 to 0.08 s, p < 0.05) between the middle and the end of the therapy. No significant changes were observed in HR, BR and SpO2 throughout the therapy. Of these three variables, only HR and BR showed a high and statistically significant positive correlation. Significance: HRV analysis seems to be a promising alternative biomarker to monitor the effect of HFNC therapy on children with severe respiratory disease. Idioma: Inglés DOI: 10.1088/2057-1976/ab2d11 Año: 2019 Publicado en: Biomedical Physics and Engineering Express 5, 4 (2019), 045028 [8 pp.] ISSN: 2057-1976 Factor impacto SCIMAGO: 0.317 - Bioengineering (Q3) - Biophysics (Q3) - Health Informatics (Q3) - Biomedical Engineering (Q3) - Radiology, Nuclear Medicine and Imaging (Q3) - Computer Science Applications (Q3) - Physiology (Q4) - Biomaterials (Q4)