What is the indication for vasopressin in CPR?

What is the indication for vasopressin in CPR?

Vasopressin, also known as antidiuretic hormone, is a potent vasoconstrictor when used at higher doses.

Vasopressin’s vasoconstrictive effect increases blood flow to the brain and heart during CPR. The vasoconstrictive effect is mediated via V₁ receptors and thus independent of the adrenergic-receptor-mediated effect of epineph-rine. Therefore, vasopressin seems to lack some of the β-adrenergic- mediated adverse effects of epinephrine, such as increased myocardial oxygen demand and tachycardia. Vasopressin currently holds a Class IIb recommendation in the treatment for pulseless VT/VF. It is not yet recom-mended for asystole and pulseless electrical activity, mainly because large studies showing improved outcome are still missing. Thus, vasopressin is currently recommended as a first-line alternative to epinephrine in patients with pulse-less VT/VF, given as a single dose of 40 U i.v. push. Because of the longer half-life of vasopressin (10–20 minutes) compared with epinephrine (3–5 minutes), and lack of supportive evidence in human trials, a second dose is not recommended at this point. Following vasopressin admin-istration and 10–20 minutes of continued CPR without the return of a perfusing rhythm, it is acceptable to return to 1 mg epinephrine every 3–5 minutes.