Fig. 4

Clinical pilot data comparing oxygen-sparing nasal reservoir cannula (OSNRC) and standard nasal cannula (SNC) in hypoxemic Ugandan children. a and b. Normalization of hypocapnia with resolving tachypnea was observed in patients using both OSNRC and SNC, with no evidence of greater CO₂ retention in the OSNRC group relative to the SNC group. c and d. Capillary blood gas pH changes were similar in OSNRC and SNC groups. e. Evidence of oxygen sparing by the OSNRC. Peripheral oxygen saturation (SpO₂) increased with increasing oxygen flow rate in patients using both OSNRC and standard nasal cannula (SNC), but was comparatively higher at several flow rates with the OSNRC. In a linear mixed-effects model, the increase in SpO₂ was 1.6% for each 1 L/min increase in flow rate and was 1.4% higher for OSNRC, relative to SNC (p < 0.0001)