Comparison of home, clinic, and catheterization oxygen saturations during the interstage period

Background: Home monitoring decreases mortality during the interstage period in patients with hypoplastic left heart syndrome. Oxygen saturations are used in medical decision making including hospitalization and timing of 2nd stage palliation. We examined if home, clinic, and catheterization saturations could be used interchangeably in making these decisions. Methods: Single center retrospective study of interstage patients from 2014 to 2018. Saturation data was compared between mean home and clinic saturations, catheterization pre-anesthesia saturation, and intra-catheterization saturations. Invasive saturations were obtained via co-oximetry. All other saturations were obtained via pulse oximetry. Home saturations were averaged over seven days centered around clinic dates or before catheterization date for comparison. Invasive saturations from the descending aorta were also compared to same day pre-anesthesia and intra-catheterization saturations. Results: 209 clinic saturations and a median of 11 home saturations per clinic visit were collected. Home saturations were 2% lower than clinic saturations (p < 0.001). Home and clinic saturations correlated (r = 0.34, p < 0.001). Mean home saturations were 4% higher than catheterization saturations from the descending aorta (p = 0.005) and did not correlate well. Same day pre-anesthesia saturations were 5% higher than catheterization saturations (p = 0.001) and were similar to the mean home saturations. Neither home saturations, clinic saturations, nor saturation trends were associated with adverse outcomes. Conclusions: Mean home saturations are lower than clinic saturations during the interstage period, but are within 2% and are correlative. Invasive catheterization saturations were significantly lower than home, clinic, and same day pre-anesthesia saturations.