Evaluation of Endothelial Function on Atherosclerosis using Perfusion Index from Pulse Oximeter

Abstract

BackgroundEndothelial dysfunction is vascular phenomenon that plays an important role in atherosclerosis development. With the purpose of improving the prevention and treatment of atherosclerotic diseases, the searching for accurate, practical and cheaper methods for evaluating endothelial function have become of interest. ObjectivesVerify the potential of Peripheral Perfusion Index from pulse oximetry (IPP) as a method of endothelial dysfunction evaluation in patients with atherosclerotic diseases. MethodsThere were recruited 18 control patients and 24 patients with atherosclerotic diseases under optimized treatment, in basic health units. The values of IPP were evaluated before and after an endothelial-dependent stimulus, the reactive hyperemia. The values of IPP were also evaluated in period which the major contribution of Nitric Oxide (NO) for the vasodilation occurs (IPP90-120). The results of IPP were discussed using the literature and estimating their diagnostic and prognostic potential ResultsThe endothelium-dependent vasodilatory response measured by IPP was significantly lower in patients with atherosclerosis compared to control group, since 45 seconds after reactive hyperemia. Also, the values of IPP90-120 were significantly lower in patients with atherosclerosis [35% (4 - 53%) vs 73% (55 - 169%); p<0,001]. Similarly, the IPP values were lower in atherosclerosis group when it was separated by gender. ConclusionThe results of this study, in association with the low cost of pulse oximeter, suggest a good potential for IPP as an endothelial dysfunction evaluation method. New studies must be done in order to clarify this potential and possibly contribute with the prevention and treatment of atherosclerotic diseases.

Perfusion index for assessing microvascular reactivity in septic shock after fluid resuscitation

“…As previously described by our group, older patients present increased basal PI values and lower reactive hyperemia; further, cardiovascular risk factors such as hypertension, diabetes mellitus and smoking can influence the reactivity test. ( 17 ) Thus, these factors were controlled in our study.…”

“…Reactive hyperemia assessment using PI was also carried out in a convenience sample of subjects matched by age, sex and without signs of clinical infection or acute illness. Due to the importance of hypertension, diabetes mellitus and smoking to microvascular reactivity, ( 17 ) the groups were approximately matched for these factors.…”

“…Subsequently, a sphygmomanometer cuff was inflated around the homolateral arm, 30 - 50mmHg above the systolic pressure, to occlude the arterial flow for a period of 3 min. ( 4 , 6 , 17 )…”

“…( 14 ) Hypoperfusion measured with PI has been shown to be predictive of mortality in sepsis, ( 15 ) and recent reports have shown that reactive hyperemia can be evaluated using PI. ( 16 , 17 )…”

Os Estudos da Reatividade Microvascular Contribuem na Prática Clínica?

“…The endothelium on this occasion acts as a mechanotransducer, perceives the shear stress and modifies its paracrine constitution, releasing vasoactive factors. 7 In the presence of disease, this endothelium-dependent dilation is reduced or absent.…”