Second-degree type II AV block is characterized by intermittent non-conducted P waves with a consistent PR interval in conducted beats. First-degree block prolongs PR without dropped beats, type I shows progressive PR lengthening, and third-degree block demonstrates complete AV dissociation.

Hypertensive emergencies are defined by acute end-organ damage. Severe neurologic findings such as seizures, focal deficits, blindness, and vomiting suggest intracranial involvement. Mild symptoms without neurologic compromise indicate urgency rather than emergency and do not require immediate aggressive blood pressure reduction.

This patient’s airway is severely compromised by massive facial trauma, but he is conscious, maintaining his own airway, and oxygenating adequately at this time. The best course is to keep him upright, provide frequent suctioning, and transport rapidly. Attempting intubation risks worsening the injury, and lying him down may obstruct his airway completely. Surgical cricothyrotomy is premature since he is still ventilating.

The most common limitation of transcutaneous pacing is failure to achieve capture due to poor pad contact, chest wall impedance, or inadequate current. Battery failure is uncommon, R-on-T is not a pacing issue, and implanted pacemakers do not prevent external pacing when properly applied.