BiPAP and CPAP: Answering all your questions
Your question : How high can you set CPAP? What are the disadvantages of CPAP that is too high? My answer . This is a good question. According to Egans, CPAP is a continuous flow of pressure on inspiration and expiration.If there are alveoli that are collapsed due to atelectasis, CPAP acts to recruit them, and open them up. It thereby acts as a splint to keep them open to improve oxygenation. If CPAP levels are set too high, alveoli will be over-distended, and this may result in air trapping. (1, page 1066) Another thing to keep in mind here is that CPAP acts to reduce venous return to the heart so the heart doesn't have to work so hard to pump blood through the body. This is the advantage of using CPAP to treat heart failure. If CPAP is set too high, this pressure may ultimately reduce venous return enough as to cause a reduction in cardiac output, which can be measured by a drop in blood pressure. Over-distended alveoli and air trapping can also result in a drop in oxygen levels,...