Iowa Code § 321J.7: Dead or unconscious persons.

A person who is dead, unconscious, or otherwise in a condition rendering the person incapable of consent or refusal is deemed not to have withdrawn the consent provided by section 321J.6, and the test may be given if a licensed physician, physician assistant, or advanced registered nurse practitioner certifies in advance of the test that the person is unconscious or otherwise in a condition rendering that person incapable of consent or refusal. If the certification is oral, a written certification shall be completed by the physician, physician assistant, or advanced registered nurse practitioner within a reasonable time of the test.