Different Responses of Ear and Finger Pulse Oximeter Wave Form to Cold Pressor Test

Awad, Aymen A.; Ghobashy, M.; Ouda, Wagih; Stout, Robert G.; Silverman, David G.; Shelley, Kirk H.

doi:10.1097/00000539-200106000-00026

Cited by 122 publications

(91 citation statements)

References 14 publications

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“…The vasoactivity of the blood vessels at the oximeter sensor site affects pulse oximeter performance [11][12][13]. Fingers have the greatest degree of vasoactivity with intense vasoconstriction.…”

Section: Discussionmentioning

confidence: 99%

The desaturation response time of finger pulse oximeters during mild hypothermia*

et al. 2004

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SummaryPulse oximeters may delay displaying the correct oxygen saturation during the onset of hypoxia. We investigated the desaturation response times of pulse oximeter sensors (forehead, ear and finger) during vasoconstriction due to mild hypothermia and vasodilation caused by glyceryl trinitrate. Ten healthy male volunteers were given three hypoxic challenges of 3 min duration under differing experimental conditions. Mild hypothermia increased the mean response time of finger oximeters from 130 to 215 s. Glyceryl trinitrate partly offset this effect by reducing the response time from 215 to 187 s. In contrast, the response times of the forehead and ear oximeters were unaffected by mild hypothermia, but the difference between head and finger oximeters was highly significant (p < 0.0001). The results suggest that the head oximeters provide a better monitoring site for pulse oximeters during mild hypothermia.

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Section: Discussionmentioning

confidence: 99%

The desaturation response time of finger pulse oximeters during mild hypothermia*

et al. 2004

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“…The developed technology was then used to investigate PPGs from the ear canal and the fingers simultaneously under simulated conditions of compromised peripheral perfusion by means of a cold pressor test as previously performed by Awad et al [15].…”

Section: Introductionmentioning

confidence: 99%

The human ear canal: investigation of its suitability for monitoring photoplethysmographs and arterial oxygen saturation

Budidha¹,

Kyriacou²

2014

Physiol. Meas.

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For the last two decades, pulse oximetry has been used as a standard procedure for monitoring arterial oxygen saturation (SpO2). However, SpO2 measurements made from extremities such as the finger, ear lobe and toes become susceptible to inaccuracies when peripheral perfusion is compromised. To overcome these limitations, the external auditory canal has been proposed as an alternative monitoring site for estimating SpO2, on the hypothesis that this central site will be better perfused. Therefore, a dual wavelength optoelectronic probe along with a processing system was developed to investigate the suitability of measuring photoplethysmographic (PPG) signals and SpO2 in the human auditory canal. A pilot study was carried out in 15 healthy volunteers to validate the feasibility of measuring PPGs and SpO2 from the ear canal (EC), and comparative studies were performed by acquiring the same signals from the left index finger (LIF) and the right index finger (RIF) in conditions of induced peripheral vasoconstriction (right hand immersion in ice water). Good quality baseline PPG signals with high signal-to-noise ratio were obtained from the EC, the LIF and the RIF sensors. During the ice water immersion, significant differences in the amplitude of the red and infrared PPG signals were observed from the RIF and the LIF sensors. The average drop in amplitude of red and infrared PPG signals from the RIF was 52.7% and 58.3%. Similarly, the LIF PPG signal amplitudes have reduced by 47.52% and 46.8% respectively. In contrast, no significant changes were seen in the red and infrared EC PPG amplitude measurements, which changed by +2.5% and −1.2% respectively. The RIF and LIF pulse oximeters have failed to estimate accurate SpO2 in seven and four volunteers respectively, while the EC pulse oximeter has only failed in one volunteer. These results suggest that the EC may be a suitable site for reliable monitoring of PPGs and SpO2s even in the presence of peripheral vasoconstriction.

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“…12,13 Additionally, it is clear that changes in autonomic tone induced by both temperature and pharmacology impact the PPG waveform. [14][15][16] Despite this complexity, the predominant contributor to the pulsatility exhibited in PPG tracing is the arterial pressure waveform.…”

Section: Physiology Of the Ppgmentioning

confidence: 99%

“…17,18 Systemic vascular resistance (SVR) and stroke volume While several investigators have documented the impact of autonomic tone on the PPG waveform, initially, no attempts were made to quantify this relationship. [14][15][16] Then, in 2007, Shelley's group attempted to use the PPG waveform to develop a quantitative estimate of SVR. 19 Specifically, this group proposed that pulse width was correlated with SVR (Pearson correlation r = 0.56) as measured in patients undergoing cardiac surgery.…”

Section: Physiology Of the Ppgmentioning

confidence: 99%

“…92 Given that about half of the measurements in this study were obtained in a state of local vasoconstriction (defined as a 50% reduction in the PPG amplitude), the authors concluded satisfactory performance of finger blood pressure measurements in this study. The PPG amplitude is widely accepted to reflect changes in local vasomotor tone; 15 whether these changes translate to global changes in vascular resistance is discussed in the Systemic vascular resistance section, above.…”

Section: Advances In Photoplethysmography 1319mentioning

confidence: 99%

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Advances in photoplethysmography: beyond arterial oxygen saturation

Bartels

Thiele

2015

Can J Anesth/J Can Anesth

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Purpose Photoplethysmography permits continuous measurement of heart rate and peripheral oxygen saturation and has been widely used to inform clinical decisions. Recently, a myriad of noninvasive hemodynamic monitoring devices using this same technology have been increasingly available. This narrative review aims to summarize the principles that form the basis for the function of these devices as well as to comment on trials evaluating their accuracy and clinical application. Principal findings Advanced monitoring devices extend photoplethysmography technology beyond measuring oxygen concentration and heart rate. Quantification of respiratory variation of the photoplethysmographic waveform reflects respiratory variation of the arterial pressure waveform and can be used to gauge volume responsiveness. Both the volume-clamp and physiocal techniques are extensions of conventional photoplethysmography and permit continuous measurement of finger arterial blood pressure. Finger arterial pressure waveforms can subsequently inform estimations of cardiac output. Conclusions Although respiratory variations of the plethysmographic waveform correlate only modestly with the arterial blood pressure waveform, fluid responsiveness can be relatively consistently assessed using both approaches. Continuous blood pressure measurements obtained using the volume-clamp technique may be as accurate as conventional brachial noninvasive blood pressure measurements. Most importantly, clinical comparative effectiveness studies are still needed in order to determine if these technologies can be translated into improvement of relevant patient outcomes. RésuméObjectif La photopléthysmographie permet la mesure continue de la fréquence cardiaque et de la saturation en oxygène périphérique, et elle est largement utilisée pour les prises de décisions cliniques. Depuis peu, un très grand nombre de dispositifs non invasifs de surveillance hémodynamique utilisant la même technologie envahit le marché. Cette synthèse narrative vise à résumer les principes à la base du fonctionnement de ces dispositifs et à commenter les essais évaluant leur exactitude ainsi que leurs applications cliniques. Constatations principales Les dispositifs de surveillance avancée étendent la technologie de photopléthysmographie au-delà de la mesure de la concentration en oxygène et de la fréquence cardiaque. La quantification de la variation respiratoire du tracé photopléthysmographique reflète la variation respiratoire du tracé de pression artérielle et peut servir à jauger la réactivité au volume. Les deux techniques de compression volumique (volume-clamp) au doigt et la technique physiocal sont des prolongements de Author contributions Karsten Bartels wrote approximately 50% of the manuscript and critically edited the remainder. Robert H. Thiele wrote approximately 50% of the manuscript and critically edited the remainder.

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Different Responses of Ear and Finger Pulse Oximeter Wave Form to Cold Pressor Test

Cited by 122 publications

References 14 publications

The desaturation response time of finger pulse oximeters during mild hypothermia*

The desaturation response time of finger pulse oximeters during mild hypothermia*

The human ear canal: investigation of its suitability for monitoring photoplethysmographs and arterial oxygen saturation

Advances in photoplethysmography: beyond arterial oxygen saturation

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