title: Photoplethysmographic variability analysis in critical care--current progress and future challenges.
abstract: The concept of early goal-directed therapy emphasizes the need for early diagnosis and intervention to achieve better therapeutic outcomes in critical care. There has been rapidly growing interest in the use of the photoplethysmogram (PPG), also known as the "pulse oximetry waveform", as a noninvasive diagnostic tool in this clinical setting. The peripheral PPG exhibits beat-to-beat variability driven by physiological mechanisms such as respiration and sympathetic vascular activity. This paper provides an overview of the current progress towards the application of PPG waveform variability (PPGV) in emergency and intensive care. Studies to date have demonstrated the potential value of PPGV for assessing a range of pathophysiological conditions including blood loss, sepsis and low systemic vascular resistance. Translation of research findings into clinical practice poses several future challenges, including the need for large scale validation studies with appropriate measurement systems, more robust solutions to signal quality issues (such as motion artifacts), and better physiological understanding of the information-rich PPGV.
authors.affiliation: School of Electrical Engineering and Telecommunications, University of New South Wales, Sydney, NSW 2052, Australia. gregchan@unsw.edu.au
authors.forename: Gregory S H
authors.initials: GS
authors.lastname: Chan
authors.forename: Paul M
authors.initials: PM
authors.lastname: Middleton
authors.forename: Nigel H
authors.initials: NH
authors.lastname: Lovell
mesh_terms: D016477:Artifacts; D044362:Australasia; D001811:Blood Volume Determination / Q000379:methods / Q000639:trends*; D003422:Critical Care / Q000639:trends*; D016638:Critical Illness; D042241:Early Diagnosis; D005544:Forecasting; D006470:Hemorrhage / Q000175:diagnosis*; D006801:Humans; D017156:Photoplethysmography / Q000379:methods / Q000639:trends*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D018805:Sepsis / Q000175:diagnosis*