Intervention and Placebo
The intervention consists of 10 mL calcium chloride 0,5 mmol/mL (5 mmol ) given as soon as possible after the first and second dose of adrenaline.
Calcium is the most abundant mineral in the body, and it is routinely given to critically ill patients either to treat hypocalcemia or in the face of iatrogenic hypocalcemia (blood transfusions, thyroidectomy, or large fluid administrations). When given intravenously, calcium has been shown to give a short hemodynamic boost, and it may help to balance out the hyperkalemic/hypocalcemic state known to present during and immediately after cardiac arrest.
The placebo consists of 10 mL sodium chloride (NaCl 9 mg/mL, “normal saline”) given as soon as possible after the first and second dose of adrenaline.
NaCl is indistinguishable from CaCl in that it is colorless and without any identifying features. It will be stored in 10 mL ampoules that are identical to the CaCl ampoules. Furthermore, except for potential slight and temporary hypercalcemia, CaCl has no distinctive rapid effects resulting in possible identification. The risk of unblinding is therefore at an absolute minimum.