Ontario Paramedic Practice Exam 2025 - Free Paramedic Practice Questions and Study Guide

The correct choice regarding the indications for initiating a medical termination of resuscitation (TOR) lies in the uniqueness of the arrest not being witnessed by Emergency Medical Services (EMS). When a cardiac arrest occurs and is not witnessed by EMS personnel, it suggests that there may be a lower likelihood of achieving a favorable outcome through resuscitation efforts. This guideline is based on studies indicating that when EMS arrives after an unwitnessed arrest, the prospects of survival and meaningful recovery decrease significantly, particularly if certain other criteria are not met during resuscitation attempts.

In contrast, scenarios such as having an altered level of awareness or no obvious return of spontaneous circulation (ROSC) may be involved in the decision-making process but do not strictly by themselves constitute indications for a termination of resuscitation. Observations like these can prompt further investigation or continued resuscitation efforts depending on the clinical judgment of the paramedics and existing protocols. Being equal to or over 30 days is not typically relevant to the immediate decisions surrounding initialization of a medical TOR, as it does not pertain to the specific circumstances of the cardiac arrest event at hand.