EM:RAP 2018 December

Robert: The major problem with CHF is that the pressures in the pulmonary capillaries are higher than the interstitial pressures allowing fluid to move from the capillaries into the alveoli. The source of the problem is the left ventricle's inability to pump blood against the pressure in the aorta (after load) leading to the back up of blood into the pulmonary circulation. BiLevel Positive Airway Pressure (BiPAP) systems increase the pressure in the pulmonary airways, increasing the pressure in the alveoli and providing a back pressure against the pulmonary capillary pressure. In addition, these systems increase the intra-thoracic pressure decreasing venous return to the right side of the heart which stops the right ventricle from forcing fluid into the overloaded pulmonary circulation. At the same time BiPAP creates an after load reducing effect on the left ventricle allowing it to empty out. Because of these pressure effects that don't exist with HFNC systems I think BIPAP or CPAP is the better respiratory support approach for CHF. Hope this helps.