Cavitation

The other night a man was brought into the trauma bay. He had been shot in the back, just inside his left wing-bone, and the bullet had traveled through his chest and exited just to the left of his sternum. “Through and through,” as we say. It never ceases to amaze me how small the wounds look on the skin. They so small, in fact, that they often fool us into thinking that they are not serious. A large chest tube was placed into his thorax, and two liters of blood rushed out. It was off to the OR.

With the help of a cardiac surgeon, we sawed through his sternum and exposed his heart. It actually looked pretty good – essentially injury free. We looked next at his left hilum, which is the beginning of his left lung and the confluence of arteries and veins there. It was a pulverized mass of destruction, hardly recognizable, with blood pouring out of a gigantic hole. He was dead, even as we identified the fatal blow.

When a bullet travels through someone it makes a track – a simple line of damage along the path of the missile. But it does something else as well. The kinetic energy of the bullet causes a cone-shaped area of destruction which is wider than the simple path. This is called cavitation.

The analogy that is often used is that of the wake of a boat. When a boat travels through the water – let’s just imagine for a moment that it’s off the coast of Maine in happier times – it obviously disturbs the water along its path. But the wake reminds us that the disruption extends much further than we might have imagined.

Personal relationships are the same way. I don’t know if it’s possible to have a serious relationship without cavitation – without that energy reaching far wider and wounding much deeper than imagined. The wounds on the surface may look deceptively small, but inside – right next to the heart – they cause massive, and potentially fatal, hemorrhage.