Abstract
Background
The time at which claudication symptoms are reported is used to modulate exercise intensity in clinical treatment of patients with peripheral arterial disease, but tissue oxygenation values at that point are unknown.
Objective
To describe tissue oxygen supply measured using Near-Infrared Spectroscopy (NIRS) when patients report initial and maximum claudication symptoms during exercise tests.
Methods
Nine patients (eight men) aged 65.63 ± 6.02 years and previously diagnosed with peripheral arterial disease performed constant load exercise testing and incremental load exercise testing while tissue oxygenation levels were monitored by NIRS. Oxygen saturation values at the times at which each patient reported initial onset of claudication symptoms and maximum claudication symptoms were compared with values obtained during the arterial occlusion maneuver, using the 95% confidence interval of the difference.
Results
It was found that saturation values at the time of both initial and maximum claudication symptoms were statistically different from saturation during the arterial occlusion maneuver, but on the basis of percentage analysis they were similar from a clinical point of view.
Conclusions
Oxygen saturations at the time patients report initial and maximum claudication symptoms are very close to saturations during arterial occlusion. From a clinical perspective, subjective patient report of symptoms is an appropriate parameter on which to base exercise prescription.
Keywords:
peripheral arterial disease; near-infrared spectroscopy; exercise test; intermittent claudication