Final answer:
Consent may be unobtainable during CPR (cardiopulmonary resuscitation) due to its clinical urgency.
Step-by-step explanation:
In certain situations, consent may be unobtainable due to clinical urgency. One such situation is during CPR (cardiopulmonary resuscitation), where immediate action is necessary to save a person's life. In this case, consent may be precluded because delay in obtaining consent could be life-threatening. CPR is a procedure performed to restore blood circulation and breathing in a person who experiences cardiac arrest or respiratory failure.