Limited Interchangeability of Shunt‐Side SpO ₂ Measurements During Hemodialysis

Introduction During hemodialysis, SpO 2 is measured on the non‐shunt side, restricting movement. This single‐center, prospective, observational study evaluated shunt‐side interchangeability. Methods Forty‐five patients underwent double‐sided finger‐sensor SpO 2 monitoring at five time points. Between‐site agreement was assessed using Lin's concordance correlation coefficient (CCC), Deming regression, Bland–Altman analysis, and accuracy root mean square (Arms). Confidence intervals were calculated using subject‐level cluster bootstrap resampling (2000 iterations; seed = 42). Using vector‐type visualization, relationships between paired measurements were illustrated. Results SpO 2 showed similar distributions between sites. The Spearman correlation was ρ = 0.705. CCC was 0.720 (95% CI: 0.590–0.811). Deming regression yielded y = 0.989 x + 1.087. Bland–Altman bias was 0.060% (limits of agreement, ±3%). Arms were 1.41%, and the visualization showed minimal angular deviation (median |θ−45°| = 0.29°). Conclusion Shunt‐side SpO 2 may be acceptable in selected clinical contexts, although interindividual variability warrants caution. These findings are not applicable to hypoxic states (SpO 2 < 90%).