There is provided herein a decision support system for cardiopulmonary resuscitation (CPR), the system comprising: a medical monitoring device configured to produce CO2 waveforms of exhaled breath of a subject undergoing CPR, and a computing unit configured to extract one or more features related to the CO2 waveforms and/or a trend thereof produced by said device, obtain one or more parameters/variables selected from a group of one or more background parameters, one or more physiological variables and one or more baseline parameters related to the subject undergoing CPR, and determine effectiveness of CPR and/or CPR outcome based at least on the one or more features and/or the trend thereof and on the one or more parameters/variables.
