Abstract 13379: The Prognostic Value of Pulse Oximetry Plethysmographic Waveform During CPR

Introduction: A facile, early predictor of the outcome of resuscitation is needed. Pulse oximetry, which noninvasively detects the blood flow of peripheral tissue, has achieved widespread clinical use. We noticed that the better the quality of CPR was, the better the appearance of pulse oximetry plethysmographic waveform (POP) was. Hypothesis: We assessed the hypothesis that the amplitude of POP (Amp) and the area under the curve of POP (AUC) could be utilised as a tool to predict the outcome of resuscitation. Methods: 617 cardiac arrest patients from 14 hospital in 10 cities were enrolled in the study and retrospectively assigned to two groups: ROSC group and non-ROSC group. Estimation of prognosis of cardiac arrested patients through the analysis of change of POP parameters during CPR. Results: POP parameters in chest compressions stage [Amp (111.0 (66.0,210.5) vs 41.0 (23.0,119.8)) PVA, AUC (3243.5±30.8 vs 2334.0 (1827.0,3229.0)) PVPG (Figure 1)] and PETCO2 [(23.1±4.0 vs 13.0(8.0,23.0)) mmHg (Figure 2)] were statistically different between ROSC group and non-ROSC group (P < 0.01). Cut-off values for ROSC in CPR patients were shown in Table 1. Conclusions: In conclusion, POP parameters could help predict the prognosis of the patients during CPR. The prognostic value of POP parameters was non inferiority to PETCO2, and this method was noninvasive, safe, economy.

Comparison between Respiratory Variations in Pulse Oximetry Plethysmographic Waveform Amplitude and Arterial Pulse Pressure during Major Abdominal Surgery

Background To assess preload dependence, the variation of the plethysmographic waveform of pulse oximetry (ΔPOP) has been proposed as a surrogate of the pulse pressure variation (ΔPP). The aim of the study was to assess the ability of the pulse oximeter-derived plethysmographic analysis to accurately trend ΔPP in patients undergoing major abdominal surgery by using standard monitors. Methods A continuous recording of arterial and plethysmographic waveform was performed in 43 patients undergoing abdominal surgery. ΔPP and ΔPOP were calculated on validated respiratory cycles. Results For analysis, 92,467 respiratory cycles were kept (73.5% of cycles recorded in 40 patients). The mean of intrapatient coefficients of correlation was low (r = 0.22). The Bland and Altman analysis showed a systematic bias of 5.21; the ΔPOP being greater than the ΔPP, this bias increased with the mean value of the two indices and the limits of agreement were wide (upper 21.7% and lower -11.3%). Considering a ΔPP threshold at 12% to classify respiratory cycles as responders and nonresponders, the corresponding best cutoff value of ΔPOP was 13.6 ± 4.3%. Using these threshold values, the observed classification agreement was moderate (κ = 0.50 ± 0.09). Conclusions The wide limits of agreement between ΔPP and ΔPOP and the weak correlation between both values cast doubt regarding the ability of ΔPOP to substitute ΔPP to follow trend in preload dependence and classify respiratory cycles as responders or nonresponders using standard monitor during anesthesia for major abdominal surgery.