Lit Matters 1: Should we give calcium for OHCA?

Routine calcium during out-of-hospital cardiac arrest with pulseless electrical activity appears harmful, not helpful. In suspected hyperkalemic arrest, ECG patterns like peaked T waves or a widened QRS did not identify a subgroup that benefited from calcium in the COCA trial analysis.

Calcium in PEA OHCA

• Routine calcium signal: Calcium chloride given during OHCA after epinephrine was associated with worse outcomes, with ROSC and 30-day survival both lower than placebo in the COCA dataset.
• PEA rhythm focus: PEA was the key subgroup because hyperkalemia commonly deteriorates into PEA, but that physiologic logic still did not translate into better resuscitation outcomes with calcium.
• ECG hyperkalemia markers: Peaked T waves, widened QRS complexes, and even ST-elevation were examined as possible selectors for benefit, and none reliably identified patients who improved with calcium. We get into the bedside implications in the episode.
• Potassium reality check: Among patients who achieved ROSC, potassium values were not markedly elevated, reinforcing that presumed hyperkalemia in undifferentiated OHCA is often less certain than the ECG suggests.
• Rhythm change after calcium: Calcium did not produce meaningful rhythm or ECG improvement after administration, undercutting the idea that an empiric dose will quickly reverse a hyperkalemic-looking arrest.
• Reasonable exception bucket: Routine use is hard to justify, but true hyperkalemia, calcium channel blocker overdose, and severe hypocalcemia remain plausible exception states where calcium may still belong.