Peripheral arterial tonometry, oximetry and actigraphy for ambulatory recording of sleep apnea

Abstract

Autonomous nervous functions change with sleep stages and show characteristic changes associated with sleep disorders. Therefore, continuous monitoring of autonomous nervous functions during sleep can be used for diagnostic purposes. Recently, the peripheral arterial tonometry (PAT) has been introduced to determine peripheral arterial vascular tone on the finger being determined by sympathetic activity. We investigate a new ambulatory recording system which uses PAT, oximetry and actigraphy (Watch-PAT) in order to detect sleep apnea and arousal. The Watch-PAT is battery operated and attached to the wrist and has two finger sensors. Twenty-one patients with suspected sleep apnea were recorded with cardiorespiratory polysomnography and the new system in parallel. Seventeen recordings could be evaluated. The correlation for the apnea/hypopnea index derived from the sleep laboratory and the respiratory disturbance index derived from the Watch-PAT was r = 0.89 (p < 0.01) and between arousals and the respiratory disturbance index was r = 0.77 (p < 0.01). The correlation for the total sleep time compared between the two systems was r = 0.15 (n.s.). The Watch-PAT detects apneas and hypopneas with a reasonable reliability and it is very sensitive to arousals. The number of Watch-PAT events lies between the sum of apneas plus hypopneas and arousals. Arousals are not unique to apnea events and therefore the specifity of the Watch-PAT is limited. In conclusion, the Watch-PAT is well suited to perform therapy control studies in patients suffering from sleep apnea and being treated.

Diagnosis of Obstructive Sleep Apnea by Peripheral Arterial Tonometry

“…However, 2 studies compared AHI between PSG and PAT conducted in a nonsimultaneous fashion. 22,26 This comparison demonstrated a correlation of 0.866 (95% CI, 0.466-0.972; P = .001). One study 23 also compared ODI between nonsimultaneously conducted PSG and PAT with a correlation value of 0.800 (95% CI, 0.613-0.902).…”

“…22,27,31 24 One additional study compared only AHI measured from home-based PAT and laboratorybased PSG. 23 The weighted AHI correlation between these 2 studies was 0.838 (95% CI, 0.581-0.943; P < .001).…”

Study Looking at End Expiratory Pressure for Altitude Illness Decrease (SLEEP-AID)

“…This device analyzes continuous oxygen saturation, oxygen desaturation events, pulse, sleep time, and stages (awake, light, deep, and REM sleep) (Herscovici et al, 2007;Bresler et al, 2008). The PAT detects transient vasoconstriction and tachycardic events that correlate pulsatile finger blood flow patterns with standard apnea-hypopnea scoring (Schnall et al, 1999;Pillar et al, 2002) to analyze sleep architecture and accurately diagnose sleep conditions Dvir et al, 2002;Penzel et al, 2004).…”

A critical review of peripheral arterial tone and pulse transit time as indirect diagnostic methods for detecting sleep disordered breathing and characterizing sleep structure

“…The pattern can also be easily identified visually and manually scored, [14] but software that performs this automatically has also been validated [13]. a reasonable sensitivity and positive predictive value [13,[15][16][17][18][19][20]. There is also an actigraphic apparatus embedded in a commercially available PAT device, which can estimate the presence of sleep and wakefulness and with an automated algorithm calculate actual respiratory disturbance index (RDI) using sleep time rather than recording time.…”