Can Pulse Oximetry Plethysmography Waveform Amplitude in Respiratory Variations Predict fluid Responsiveness on Spontaneously Breathing Adult Shock Patients?

ABSTRACT

PURPOSE: It is difficult to predict volume responsiveness in hemodynamically unstable patients with spontaneous breathing activity. Our objective was to test whether the respiratory variations in pulse oximetry plethysmography (POP) waveform amplitude could predict fluid responsiveness to fluid resuscitation (FR) in spontaneously breathing adult shock patients. METHODS: We investigated 21 patients presenting with shock in the Emergency Room. We assessed hemodynamic status and calculated the respiratory variations in POP waveform amplitude before and after FR. Heart rate, blood pressures (MAP, SBP), maximal POP (POPmax), minimal POP (POPmin) and deltaPOP, defined as deltaPOP = (POPmax - POPmin) / ([POPmax + POPmin] / 2) were recorded. We measured hemodynamic parameters by doppler ultrasound, USCOM(R). RESULTS: Comparisons of hemodynamic parameters between before and after FR showed no significant difference in heart rate, but POP showed significant differences in changes in SBP, MAP, cardiac index, stroke volume index and respiratory variations. In response group(> or =15% in delta CI), the change in cardiac index, stroke volume index, and the respiratory variation in the POP were not significantly different. CONCLUSION: In spontaneously breathing patients with shock, we suggest that delta POP is not a reliable parameter in the prediction of fluid responsiveness.