A method for determining an efficacy of cardiopulmonary resuscitation (CPR) includes receiving a plethysmography signal from an oximetry sensor and an electrocardiogram (ECG) signal from an ECG sensor at a processor associated with a patient monitor, the oximetry sensor, or the ECG sensor. The method includes determining a first indicator related to the efficacy of CPR based on the plethysmography signal, using the processor. The method also includes determining a second indicator related to the efficacy of CPR based on the ECG signal, using the processor. The method further includes combining the first indicator and the second indicator to determine a combination metric indicative of the efficacy of CPR, using the processor.