Effect of hemiparetic stroke on pulse oximetry readings on the affected side

Background and Purpose-Hypoxia is common after stroke, and monitoring by pu lse oximetry is suggested in the acute phase. Physical changes on the affec ted side or intravenous infusions may affect oximeter readings. This study was designed to test whether pulse oximetry recordings are the same on the affected and nonaffected sides in stroke patients. Methods-Oxygen saturation (Spo(2)) and heart rate (HR) were assessed simult aneously in the left and right hands in patients with hemiparetic stroke ov er a 3-hour period with 2 Minolta Pulsox-3i oximeters attached to the index fingers. Results-Fifteen patients (53% men: 67% left hemiparesis; mean age, 73 years [SD, 7.5 years]) were recruited. HR and Spo(2) (12 measurements per minute ) were monitored. The maximum difference between simultaneous left and righ t arm readings was 2% Spo(2). HR fluctuated more. but no affected/nonaffect ed side pattern was seen. Means for each patient of HR and Spo(2) for the a ffected and nonaffected sides were compared by t tests. Mean Spo(2) was 96% (SID, 1%) on both sides. Mean HR was 81 bpm (SID, I I bpm) on the affected side and 80 bpm (SID, 10 bpm) on the nonaffected side. There was no signif icant difference between the 2 sides for either parameter (n = 15; P = 0.86 for Spo(2) and P = 0.91 for HR). Conclusions-Oximeters can be attached to either the affected or nonaffected side in hemiparetic stroke.