Pneumothorax and hemothorax: Nursing

Pneumothorax and hemothorax are conditions that affect the pleural space surrounding the lungs. When air leaks into this space, it’s called a pneumothorax; whereas when blood fills this space, it’s called a hemothorax.

Now, let’s quickly review the anatomy and physiology of the pleural space. The lungs are lined with a membrane called the visceral pleura, while the chest cavity is lined with the parietal pleura. The thin space between these two membranes is called the pleural space. The pressure within the pleural space is negative, meaning it’s below atmospheric pressure. Now, the lung tissue’s elastic recoil applies a constant force that tries to contract the lungs, kind of like a stretched out rubber band. To prevent the lungs from shrinking, the negative pleural pressure around the lungs pulls the lung parenchyma outwards and counteracts the elastic recoil.

When a person inhales, the alveolar pressure becomes lower than the atmospheric pressure, which allows the air to enter the lungs. During exhalation, the alveolar pressure becomes greater than the atmospheric pressure, letting air move out of the lungs. However, at all times, the pleural pressure will remain lower than both the atmospheric pressure and the alveolar pressure, which helps prevent the lung from completely collapsing. Now, if pneumothorax or hemothorax occur, this physiological function of the pleural space gets disrupted.

Pneumothorax is categorized as either open or closed, depending on its cause. An open pneumothorax is caused by an opening in the chest wall that allows air to enter the pleural cavity from outside the body. A common type is traumatic pneumothorax due to a penetrating injury like a knife wound.

On the other hand, a closed pneumothorax results from an injury to the lungs that allows air to escape into the pleural space. This could be due to a traumatic cause, such as a broken rib from blunt damage piercing the lung, or an iatrogenic cause where a central venous line punctures the apical lung tissue during insertion.