Chest Tube STAT!

I must confess that I love watching medical dramas on TV. Most physicians hate them because they exaggerate the way medicine is really practiced, but I think they're just plain entertaining and I've actually learned a thing or two from them.

But one thing does bother me. Every other patient who goes to the ER gets a chest tube. And it always happens the same way. Someone shouts, "we need a chest tube in here STAT!" A junior resident/student tries to insert the chest tube and fails. The senior resident angrily pushes him aside and easily slides in the chest tube. There's a gush of air and a change in the cadence of the beeping monitors. The patient coughs and sits straight up, clearly revived. Someone says, "good work, people". Two doctors start making out and then 3 episodes later, one has amnesia.

In my 5 years as a medical student and intern, I have never witnessed a STAT chest tube insertion in the ER, but I guess it makes for good drama on TV.

I thought I would explain exactly how breathing mechanics work and why chest tubes need to be inserted.

There are 2 fundamental structures involved in taking a breath. The lungs and the chest cavity. Lungs are really just a bag of air, like a balloon. It has blood vessels and some other tissue, but it mainly just holds air. The chest cavity (comprised of the rib cage and diaphragm) is a rigid scaffolding which protects the lungs and acts as an anchor for the muscles which allow breathing to occur.

The entire system can be thought of as a balloon within a balloon (the inside balloon is the lungs and the outside balloon is the chest cavity). Because the chest cavity has ribs, it is actually rigid so that it cannot really expand/contract as much as the inside balloon can. But the chest cavity does have a diaphragm.

The diaphragm is a muscle which can make the chest cavity bigger and smaller depending on how contracted it is. When you take a breath, the diaphragm contracts downward and expands the chest cavity. Because the rest of the chest cavity is rigid (because of the ribs), and the lungs are very elastic, air is sucked into the lungs. The lungs are now expanded with air.

Exhaling is mostly a passive process. The diaphragm relaxes, making the chest cavity smaller and allowing the lungs to blow air gently out.

That's all it takes to breath.

Chest tubes come into play when the lung collapses (in medical terms, a pneumothorax).
In real life, the lungs and chest cavity are not stuck together. There is actually a space separating the two (called the pleural space). But functionally, the lungs and chest cavity are stuck together because this space is usually sealed under a negative "sucking" pressure. So when your chest cavity pulls outward (expands), it pulls on the
pleural space, which in turn pulls on the lungs, which expands because the lungs are elastic.

When you lose the negative sucking pressure in the pleural space, the lung collapses. The lung is incredibly elastic. If nothing is holding it expanded, it will just collapse like a rubber band. This can happen if a bullet or knife penetrates the chest cavity, poking a hole into the pleural space and breaking the seal. When a chest tube is inserted, it is usually hooked up to a suction. The suction replaces that negative pressure and allows the lung to expand again until that hold is healed over and sealed once again.

Pneumothoraces can definitely be life threatening and need to be diagnosed in a timely fashion. They are always on your list of possible diagnoses when a patient presents with shortness of breath. But they are not nearly as common as seen on TV. Furthermore, when they do present, it is not always in such an acute fashion.