Principles and role of photoplethysmography in anesthesiology and intensive care medicine
DOI:
https://doi.org/10.66166/cjaim.2.1.3Keywords:
photoplethysmography, anesthesiology, intensive care medicineAbstract
Photoplethysmography (PPG) is a non-invasive optical method that detects blood volume changes in the skin microcirculation. Since it's first description in 1938, PPG has evolved from a research tool into a key component of clinical monitoring, particularly with pulse oximetry. This narrative review summarizes the principles, waveform characteristics, contemporary theories, as well as future application of finger PPG in anesthesiology and intensive care medicine. A literature search was conducted using PubMed and Google Scholar with the keywords "photoplethysmography," "anesthesiology," and "intensive care medicine." OpenEvidence AI was used as a supplementary tool. Retrieved articles were independently reviewed for relevance and methodological quality. Finger PPG signals comprise pulsatile and non-pulsatile components, reflecting cardiac cycle. Waveform morphology is influenced by microcirculatory blood volume, arterial pressure, autonomic tone, and vascular compliance. Clinically, PPG underlies pulse oximetry and provides information on nociceptive stimuli, anesthesia depth, and sympathetic activity. Parameters such as perfusion index (PI), pulse transit time (PTT), and area under the photoplethysmographic curve (AUCPPG) have been explored to assess regional anesthesia efficacy and volume status. Emerging technologies enable continuous, non-invasive arterial pressure and cardiac output monitoring via algorithmic interpretation of PPG-derived signals. Finger PPG is a versatile, non-invasive tool with established and emerging applications in anesthesiology and critical care. Advances in signal analysis and device technology are expanding it's role in continuous hemodynamic monitoring, potentially enhancing patient management and safety in perioperative and intensive care settings.
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