Photoplethysmographic characterization of vascular tone mediated changes in arterial pressure: an observational study
- 40 Downloads
To determine whether a classification based on the contour of the photoplethysmography signal (PPGc) can detect changes in systolic arterial blood pressure (SAP) and vascular tone. Episodes of normotension (SAP 90–140 mmHg), hypertension (SAP > 140 mmHg) and hypotension (SAP < 90 mmHg) were analyzed in 15 cardiac surgery patients. SAP and two surrogates of the vascular tone, systemic vascular resistance (SVR) and vascular compliance (Cvasc = stroke volume/pulse pressure) were compared with PPGc. Changes in PPG amplitude (foot-to-peak distance) and dicrotic notch position were used to define 6 classes taking class III as a normal vascular tone with a notch placed between 20 and 50% of the PPG amplitude. Class I-to-II represented vasoconstriction with notch placed > 50% in a small PPG, while class IV-to-VI described vasodilation with a notch placed < 20% in a tall PPG wave. 190 datasets were analyzed including 61 episodes of hypertension [SAP = 159 (151–170) mmHg (median 1st–3rd quartiles)], 84 of normotension, SAP = 124 (113–131) mmHg and 45 of hypotension SAP = 85(80–87) mmHg. SAP were well correlated with SVR (r = 0.78, p < 0.0001) and Cvasc (r = 0.84, p < 0.0001). The PPG-based classification correlated well with SAP (r = − 0.90, p < 0.0001), SVR (r = − 0.72, p < 0.0001) and Cvasc (r = 0.82, p < 0.0001). The PPGc misclassified 7 out of the 190 episodes, presenting good accuracy (98.4% and 97.8%), sensitivity (100% and 94.9%) and specificity (97.9% and 99.2%) for detecting episodes of hypotension and hypertension, respectively. Changes in arterial pressure and vascular tone were closely related to the proposed classification based on PPG waveform.
Clinical Trial Registration NTC02854852.
KeywordsArterial pressure Photoplethysmography Vasodilation Vasoconstriction Vascular tone
Compliance with ethical standards
Conflict of interest
No potential conflicts of interest exist except for Matías Madorno who is partner and manager of MBMed S.A; a company that produce respiratory monitoring equipments.
Informed consent was obtained from all individual participant included in the study.
- 1.Walsh M, Devereaux PJ, Garg AX, Kurz A, Turan A, Rodseth RN, Cvwinski J, Thabane L, Sessler DI. Relationship between intraoperative mean arterial pressure and clinical outcomes after noncardiac surgery. Toward an empirical definition of hypotension. Anesthesiology. 2013;119:507–15.CrossRefGoogle Scholar
- 26.Randall OS, Westerhof N, van den Bos GC, Alexander B. Reliability of stroke volume to pulse pressure ratio for estimating and detecting changes in arterial compliance. J Hypertens. 1986;4:293–6.Google Scholar
- 28.Broch O, Renner J, Gruenewald M, Meybohm P, Höcker J, Schöttler J, Steinfath M, Bein B. Variation of left ventricular outflow tract velocity and global end-diatolic volume index reliability predict fluid responsiveness in cardiac surgery patients. J Crit Care. 2012;27:325e7–14.CrossRefGoogle Scholar
- 38.Hashimoto J, Chonan K, Aoki Y, Nishimura T, Ohkubo T, Hozawa A, Suzuki M, Matsubara M, Michimata M, Araki T, Imai Y. Pulse wave velocity and the second derivative of the finger photoplethysmogram in treated hypertensive patients: their relationship and associating factors. J Hypertens. 2002;20:2415–22.CrossRefGoogle Scholar
- 39.Peñaz J. Criteria for set point estimation in the volume clamp method of blood pressure measurement. Physiol Meas. 1992;41:5–10.Google Scholar
- 48.Fischer GW, Levin MA. Vasoplegia during cardiac surgery: current concepts and management. Semin Thorac Surg. 2010;22:140–4.Google Scholar