Approach to Undifferentiated Cardiac Arrest

The resuscitation of a patient who is in cardiac arrest of unknown etiology in PEA or asystole proceeds with the simultaneous management of the ABCs and addressing the likely elements in the differential. Think Hs and Ts.

– Hypoxia (Place LMA or ETT, provide 100% oxygen)
– Hypovolemia (Bedside ultrasound for free abdominal fluid/AAA, consider a NS bolus – if suspicion for hemorrhage is high, administer uncross-matched blood)
– Hypo/hyperkalemia (Consider calcium chloride, especially in the patient with suspected renal insufficiency)
– Hypoglycemia (Consider D50)
– Hypothermia (Warm the cold patient)
– Hydrogen ion/acidosis (Consider bicarb, especially if toxicology is suspected)
– Toxins (In addition to bicarb, consider empiric antidotes – cyanide kit, digibind, naloxone, intralipid)
– Tamponade (Perform bedside ultrasound)
– Tension pneumothorax (Perform bedside ultrasound / consider needle or tube thoracostomy)
– Thrombosis (Consider thrombolysis for AMI or, especially PE)
– Trauma (The entire cranium and posterior thorax should be inspected if occult trauma is entertained)

Although the administration epinephrine (and, formerly, atropine) is emphasized in codes, these agents do not benefit arrested patients. Your only chance to reanimate a patient in PEA or asystole is to reverse the underlying cause. Take your own pulse, take a step back, and think Hs and Ts.