In conclusion, the patient's physiological reserve capacity is an important outcome predictor for cardiac arrest, and one that is seldom reported due to recording limitations. The simplest MEWS system is a composite of vital sign parameters and not only can be used as premonitory clinical information to prevent death and trigger early aggressive treatment, but the score could also be considered as an independent predictor of mortality after resuscitation. It could be viewed as another factor in the decision regarding the termination of resuscitation of a patient, especially in patients with multiple comorbidities with low physiological reserves.