“…However, there are no criteria for detecting IHCA based on patients’ objective monitored data. Several studies have suggested methods for recognizing deterioration in monitored patients based on combinations of ECG, ABP waveform, pulse oximetry, and end-tidal CO 2 , but none have been prospectively validated ( 28 , 33 , 34 ). We believe, based on our findings, that monitoring changes in an expanded range of derived physiologic variables, including proxies for CO, SV, and SVR, may permit more proactive recognition of deterioration and possibly earlier CPR initiation.…”