Monitoring of Cardiovascular Reactivity to Cold Stress Using Digital Volume Pulse Characteristics in Health and Diabetes

Abstract

This preliminary study suggests that the collective responses of PPG amplitude and PTT can be used to objectively quantify the sympathetic reactivity to cold stress in health as well as to detect the deficits of vascular reactivity in diabetes. Further studies would substantiate the simple PPG technique in quantifying the neuronal and vascular dysfunction.

Postoperative Pain Assessment Indices Based on Photoplethysmography Waveform Analysis

“…These results can be explained by increased blood vessel resistance shown in pulse area change or decreased maximum blood volume due to vasoconstriction. From a similar viewpoint, significant increase in L sys indicates that contracted vessels might have increased the vascular resistance due to vasoconstriction of the sympathetic nerves (Jaryal et al, 2009; Hickey et al, 2016). TriA, TriA sys , and TriA dia in the area of a triangle where the waveform of the high frequency component such as harmonics was removed showed similar patterns as those of A, A sys , and A dia , respectively.…”

Diabetes and impaired glucose metabolism is associated with more cold-related cardiorespiratory symptoms

“…Diabetic complications in the extremities, such as peripheral vascular disease, as well as peripheral neuropathy alter the ability to regulate heath loss in the extremities [20]. For instance, the vasoconstriction response towards local cooling is impaired in those with diabetes [18,29] which could favor heat loss in a cold environment. On the other hand, tissue perfusion may be decreased in autonomic neuropathy [30] and cooling of the skin may further reduce blood flow to the extremities and their tissues in subjects with diabetes [19], especially in those with cardiovascular autonomic neuropathy [17].…”

Area difference ratio for assessing nociceptive balance during laryngoscopy and intubation under intravenous anaesthesia

“…Because the contour of the PPG is modulated mainly by the cardiovascular system as a whole, rather than peripheral perfusion, it should not be subject to these influences. 3 In an earlier study, 4 we found that the area difference ratio (ADR) could configure the contour of the PPG and was related to the product of peripheral resistance R and total arterial compliance C. 5,6 In this study, we investigated the performance of ADR in assessing the balance of nociception during and after intubation under general anaesthesia by comparing it with PPGA. We hypothesised that ADR would be a better measurement of the balance of nociception under general anaesthesia.…”