Changes in the photoplethysmogram with tracheal intubation and remifentanil concentration

Abstract

SummaryAutonomic sympathetic activation, for instance following noxious stimuli, decreases the size and flattens the shape of the photoplethysmographic peripheral pulse waveform. We report a simple measure of the waveform shape, the ratio of mean-to-peak wave amplitude, for measuring nociception level during general anaesthesia. Fifty participants, anaesthetised with propofol and remifentanil, were randomly allocated to one of three different remifentanil effect-site concentrations (1, 3 and 5 ng.ml , were 0.49 (0.03), 0.48 (0.03) and 0.45 (0.04), respectively. Remifentanil therefore suppressed changes in the mean-to-peak ratio caused by tracheal intubation (p = 0.006). The ratio of the mean-to-peak plethysmographic amplitude may represent a simple measure of the balance of autonomic sympathetic and parasympathetic activity under general anaesthesia, and its performance following intubation was significantly different from peak amplitude (p = 0.046).

To clarify features of photoplethysmography in monitoring balanced anesthesia, compared with Cerebral State Index

“…A standard unit for measuring photoplethysmogram waveform amplitude does not exist, thus the index of the PPGA can only be recorded according to the tendency of context [17]. The baseline of photoplethysmogram waveform amplitude (PPGA (0) ) was recorded as 1 arbitrary unit, and PPGA of other points recorded as the ratio of PPGA (n) /PPGA (0) , and the PBI was extracted from the photoplethysmogram waveform.…”

“…The baseline of photoplethysmogram amplitude (PPGA (0) ) was recorded as 1 arbitrary unit (au), and the PPGA of other points was recorded as the ratio of PPGA (n) /PPGA (0) , and the PBI was extracted from photoplethysmogram waveform. Figure 1 clarifies the parameters from a standard photoplethysmogram wave that responds to nociception: photoplethysmogram amplitude (PPGA), notch amplitude (PPG n), pulse beat interval (PBI), and area under the curve (AUC) [16,17]. CSI and MAP were consecutively monitored and recorded.…”

Comparison of the effect of different infusion rates of sufentanil on surgical stress index during cranial pinning in children under general anaesthesia: a randomized controlled study

“…We based our sample size calculations on a previous study performed on adult patients [ 14 ], as there was no similar study in children, and used G*Power© software (version 3.1, Franz Faul, Universitaet Kiel, Germany). Differences in mean-to-peak ratios of PPG were assumed to be 0.02 and the standard deviation was assumed to be 0.02, according to the previous study.…”

“…Recently, a variety of methods have been suggested to monitor nociception during anaesthesia: pupillometry [ 7 ], surgical pleth index (SPI) [ 8 ], surgical stress index (SSI) [ 9 ], skin conductance [ 10 ], analgesia/nociception index [ 11 ], cardiovascular depth of analgesia index [ 12 ], wavelet transform cardiorespiratory coherence [ 13 ], photoplethysmogram amplitude (PPGA) [ 14 ], and nociception level index [ 15 ]. However, as most of these measurements require specific monitoring devices, they may be impossible to implement without the aid of specific devices that are not available in every clinical setting.…”

Methods of Extracting Feature from Photoplethysmogram Waveform for Non-Invasive Diagnostic Applications

“…HR can be extracted from PPG morphology by monitoring the peak-to-peak (P-P) interval of a PPG signal. HR is an important feature for detecting cardiac diseases [13]. DT is the time difference between systolic and diastolic peaks and is related to the time taken for the pressure wave to propagate from the heart to the periphery and back [31].…”