In the randomized controlled study comparing high- dose insulin to vasopressors or combination therapy in a porcine model of refractory propranolol-induced cardiogenic shock, why was it important to maintain a MAP of greater than 55 mmHg?
In humans, the literature suggests that cerebral blood flow is maintained provided that the cerebral perfusion pressure is within 50–150 mmHg. In refractory PICS, the MAP falls below the lower limit of autoregulation and cerebral ischemia occurs. While insulin may maintain the vasodilation in the brain to avoid microcapillary ischemia, the peripheral vasoconstriction and resultant increased MAP affected by the addition of the vasopressor may better maintain the animal in this range of autoregulation and stave off a drop in cerebral perfusion pressure.
Katzung KG, Leroy JM, Boley SP, Stellpflug SJ, Holger JS, Engebretsen KM. A randomized controlled study comparing high-dose insulin to vasopressors or combination therapy in a porcine model of refractory propranolol-induced cardiogenic shock. Clin Toxicol (Phila). 2019 Nov;57(11):1073-1079.
Contrbibuted by: Dawn Sollee, PharmD DABAT & Molly Stott, PharmD on behalf of the Florida/USVI Poison Information Center-Jacksonville