One of the tenets of neurosurgery, perhaps the principal tenet, is the Monro-Kellie doctrine: that the cranium, the bone that encases the brain, can fit only so much . Though it affords our brains a home and remarkable protection, that comes at a cost. If its tenant gets too big, the pressure inside rises, and there’s nowhere for the brain to go but down, a harbinger of death. When our patient bled, the blood that seeped into his cranium occupied space he didn’t have.

We can try to treat this pressure medically, but in an emergency like this, the definitive treatment is to place an external ventricular drain. Since the French surgeon Claude-Nicolas Le Cat first performed it in 1744, placing this fine tube into the brain has been used as a swift and durable way to drain some of the cerebrospinal fluid that buoys and nourishes the brain, creating space and relieving pressure.

It was my job to place it.

We calmed and sedated him, his cardiac monitor periodically reminding us of his starving heart muscle. I carefully shaved the little hair he had. I scrubbed his scalp with a soapy sponge, cleaned it with rubbing alcohol, and painted it with bactericidal iodine. The room was soon clad in hospital blue drapes, with him at the center, a light illuminating his crown. The light beamed hot over my mask and gown.

As I cut into his scalp, his blood spilled forth , as thinned blood does. That familiar scent immediately filled my nostrils. I scraped away the subcutaneous tissue revealing his ivory white cranium. I started drilling a hole, to break the cerebral seal we are all born with. Once through, I cut his dura mater, the rubbery sheath of tissue that encases the brain. He was now exposed. Using external anatomic landmarks as my guide, I gently passed the tube into his brain. You can’t help but to notice the brain’s jellylike consistency.

Crimson cerebrospinal fluid gushed out. Success.

With such insults to the brain, it isn’t as much a race against time. Yes, time is tissue. But really, this was a race against space. He now had a little more room to suffer his bleed.

I sutured the tube into place, and closed his incision. We took him upstairs to the neurological intensive care unit. Between his brain and his heart, the former was the priority. Remarkably, his heart never stopped beating.

Later that evening, his family and friends trickled into the unit to visit him. “What are his chances?” is always the first question. It was difficult to be certain, but his prognosis was poor. Even with our best efforts, he was now comatose, reacting very little to the world around him.