What happens when pressure in the chest cavity becomes greater than atmospherics pressure?

When pressure in the chest cavity becomes greater than atmospheric pressure, it can lead to several consequences:

1. Collapsed Lungs: If the pressure inside the chest cavity exceeds the atmospheric pressure outside, the lungs may collapse. This condition is called atelectasis. It occurs when the alveoli, the tiny air sacs in the lungs, are compressed and cannot expand fully, leading to reduced lung volume and difficulty breathing.

2. Difficulty Breathing: The increased pressure in the chest cavity can make it challenging to breathe. This is because the muscles involved in breathing, such as the diaphragm and intercostal muscles, have to work harder to overcome the higher pressure to inflate the lungs.

3. Reduced Lung Compliance: Lung compliance refers to the lungs' ability to expand and contract with ease. When pressure in the chest cavity is elevated, the lungs become stiffer and less compliant. This reduced compliance makes breathing even more difficult.

4. Cardiovascular Effects: Increased pressure in the chest cavity can also affect the cardiovascular system. It can put pressure on the heart, making it harder to pump blood effectively. This can lead to a decrease in cardiac output, affecting the overall circulation and oxygen delivery to tissues.

5. Mediastinal Shift: In severe cases, the increased pressure in the chest cavity can cause the mediastinum, the space between the lungs, to shift to one side. This shift can put pressure on structures in the mediastinum, such as the heart, major blood vessels, and airways, leading to further complications.

6. Respiratory Distress: If the pressure imbalance becomes severe and breathing becomes extremely difficult, it can result in respiratory distress. This condition requires immediate medical attention as it can lead to respiratory failure and life-threatening complications.

It is important to note that sudden and significant increases in chest cavity pressure are usually associated with specific medical conditions or events, such as trauma, respiratory illnesses, or mechanical ventilation. Prompt evaluation and management by healthcare professionals are crucial in these situations to address the underlying cause and minimize potential complications.