Oxycodone is a medication used to relieve moderate to severe pain. In this clinical trial, it is administered through a patient-controlled analgesia (PCA) system, allowing patients to manage their pain by controlling the amount of medication they receive. The study aims to evaluate how oxycodone affects breathing, specifically looking at oxygen levels in the blood and breathing rates after cardiac surgery.

Coronary Artery Disease – This condition involves the narrowing or blockage of the coronary arteries, usually due to a buildup of cholesterol and fatty deposits called plaques. Over time, these plaques can harden or rupture, leading to reduced blood flow to the heart muscle. This can cause chest pain, known as angina, especially during physical activity or stress. If a plaque ruptures, it can lead to a heart attack. The disease progresses as the arteries become increasingly narrowed, potentially leading to more severe symptoms and complications.

Aortic Valve Disease – This disease affects the aortic valve in the heart, which controls blood flow from the heart to the aorta and onward to the rest of the body. It can involve either narrowing (stenosis) or leaking (regurgitation) of the valve. As the condition progresses, it can lead to symptoms such as shortness of breath, fatigue, and chest pain. Over time, the heart may have to work harder to pump blood, which can lead to heart failure if untreated.

Mitral Valve Disease – This condition affects the mitral valve, which regulates blood flow between the left atrium and left ventricle of the heart. It can involve mitral valve stenosis, where the valve does not open fully, or mitral valve regurgitation, where the valve does not close properly. As the disease progresses, it can cause symptoms like shortness of breath, fatigue, and irregular heartbeats. The heart may become enlarged or weakened over time due to increased workload.

Tricuspid Valve Disease – This disease affects the tricuspid valve, which controls blood flow between the right atrium and right ventricle. It can involve tricuspid stenosis or regurgitation, leading to improper blood flow through the heart. As the condition progresses, it can cause symptoms such as swelling in the abdomen or legs, fatigue, and irregular heart rhythms. Over time, it can lead to complications such as heart failure if not managed properly.