text: Early CPR has been shown to be predictive of survival to hospital discharge,5-7 and minimizing time between compressions and defibrillation was shown to increase the likelihood of shock success for VF/VT arrests.8,9 Studies such as these demonstrate the importance of early, high-quality, uninterrupted chest compressions, whereas other cardiac arrest therapies such as advanced airways and certain medications have not been proven to increase survival rates.10-16 Further research has demonstrated that providers often take too long to check for a pulse17,18 and that pausing for a pulse check after a defibrillation may decrease myocardial perfusion during the critical postdefibrillation period.4
  In place of manual pulse checks, the ACLS guidelines propose using physiologic measurements to identify ROSC, such as central venous oxygen saturation (SCVO2) or end-tidal CO2 (PETCO2).