You have arrived on the scene to find a dialysis patient. The patient is responding to verbal stimuli with incomprehensible words. You can palpate a weak radial pulse and the patient is breathing 12 times per minute. Which of the following is an appropriate treatment for this patient?

A. synchronized cardioversion with 50 joules
B. Begin immediate transcutaneous pacing
C. administration of a 1.5 mg/kg lidocaine bolus IV
D. administration of 1 g calcium chloride IV CONFIRM