Techniques for predicting fluid responsiveness or fluid unresponsiveness are described. A processor can determine a first prediction of fluid responsiveness or unresponsiveness based on a plethysmograph variability parameter associated with a plethysmograph waveform, and can determine a second prediction of fluid responsiveness or unresponsiveness based on a fluid responsiveness parameter that is associated with an elevation of one or more limbs of the patient. The processor can determine an overall prediction of fluid responsiveness or unresponsiveness based on the first and/or second predictions. Based on overall prediction, the processor can cause administration of fluids and/or termination of administration of fluids.
