Heart Lung Machine Research Paper

Literary Review-Group 1-Afolabi-Baker-Buckley-Forristal-Hanna

History of the Heart-Lung Machine( Cardiopulmonary Bypass Pump) The inventor of the Heart Lung Machine was John Heysham Gibbon (Bellis, 2016). Gibbon spent twenty-three years working on this project before the first successful application was built. He studied at the Jefferson Medical College of Philadelphia and went on to complete his residency at Pennsylvania Hospital (Colm, 2003).

The first successful prototype was used to keep a cat alive for 26 minutes. His research was interrupted due to the outbreak of World War 2 (Bellis, 2016). After the war, he recommenced his research and developed a new design. By

perform the function of the lungs). There are two main types of oxygenators, “Bubble” and “Membrane”. High., Bashien, Kurusz (2008) describes these oxygenators. Usually in a bubble oxygenator there is two chambers. In the first chamber venous/deoxygenated blood enters. In here the blood is mixed with a mixture of fresh oxygen and carbon dioxide bubbles (Before the gas enters the chamber it is passed through a special screen which causes the gas bubbles to form). In the mixing chamber the oxygen and carbon dioxide bubbles diffuse into the blood. Enough time must be allowed in this section so that an adequate amount of gas exchange to happen. In the next chamber defoaming occurs and any excess bubbles are removed. Membrane Oxygenators work much like the human lung. There is a thin membrane separating the gas and the blood, which the oxygen and carbon dioxide molecules diffuse across much like in the lung where they diffuse across the wall of the Alveolus and into the Capillaries. There is less of a risk of gas emboli (This is where bubbles cause a blockage in a blood vessel, it is more commonly known as “the bends” and can be lethal) occurring when using a membrane oxygenator as unlike the bubble oxygenator it does not force bubbles into the blood. However the cost of making the membrane oxygenators is a lot higher than bubble oxygenators and membrane oxygenators can only be used in complex open-heart surgery. A clinical trial (Fenchel et al.1979) performed on two similar groups of patients having cardiac surgery showed that there is no major difference in performance up until 90 minutes had passed. After this time the membrane oxygenator starts to massively outperform the bubble oxygenator, particularly when it comes to hemolysis occurring (this is where red blood cells rupture and flood the surrounding cells and area with their