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

Abstract

Background and Purpose - Hypoxia is common after stroke, and monitoring by pulse oximetry is suggested in the acute phase. Physical changes on the affected 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 (Spo2) and heart rate (HR) were assessed simultaneously in the left and right hands in patients with hemiparetic stroke over 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 Spo2 (12 measurements per minute) were monitored. The maximum difference between simultaneous left and right arm readings was 2% Spo2. HR fluctuated more, but no affected/nonaffected side pattern was seen. Means for each patient of HR and Spo2 for the affected and nonaffected sides were compared by t tests. Mean Spo2 was 96% (SD, 1%) on both sides. Mean HR was 81 bpm (SD, 11 bpm) on the affected side and 80 bpm (SD, 10 bpm) on the nonaffected side. There was no significant difference between the 2 sides for either parameter (n=15; P=0.86 for Spo2 and P=0.91 for HR). Conclusions - Oximeters can be attached to either the affected or nonaffected side in hemiparetic stroke.