A system is provided including a ventilator detection module, a circulatory detection module, and an analysis module. The ventilator detection module is configured to detect ventilator information representative of a ventilation activity. The circulatory detection module is configured to detect circulatory information representative of the circulation of the patient. The analysis module is configured to obtain a ventilator waveform based at least in part on the ventilator information, obtain a circulatory waveform based at least in part on the circulatory information, combine the ventilator waveform and the circulatory waveform to provide a mixed waveform, and isolate a portion of the mixed waveform to identify a ventilator responsiveness waveform representative of an effect of the ventilator.