Saturday, April 12, 2008

The thrill of victory and the agony of defeat

Sometimes in neurosurgery the greatest technical triumphs coincide with the greatest patient care defeats. That is, often those tasks that require the most manual dexterity or technical proficiency only present themselves because your patient is in a dire situation. I can provide an example from a recent call night. We had a patient come in with a severe subarachnoid hemorrhage. Here's a CT scan:


That whitish stuff towards the center of the picture (worse on the right, which, in the backwards world of radiological imaging, refers to the patient's left) is hemorrhage that's not supposed to be there. The astute interpreter of head CT scans will also note significant cerebral edema, with effacement of the basal cisterns. That is to say that the cisternal spaces around the brainstem, in which cerebrospinal fluid normally circulates freely in a healthy brain, have been compacted by the pressure in the cranium. Not surprisingly, this patient was what we would term moribund; on the five point grading scale of severity of subarachnoid hemorrhage, he was a five. When he arrived in the emergency department he showed practically no sign of neurological function.

However, this patient happened to be quite young--so young, in fact, that we wanted to give him every possible chance at recovery. In this case that included administering a medication, Mannitol, to reduce the intracranial pressure (ICP), as well as hyperventilating him (which also reduces ICP). The next option to entertain for treating high ICP is to drain off some cerebrospinal fluid from the ventricles of the brain. Here's another scan:


This is an image of the patient's brain at the level of the foramen of Monroe. Those two little darker slits towards the center/front of the scan are the lateral ventricles where they come together and drain into the third ventricle through the foramen of Monroe. When we place a ventriculostomy catheter, which is a rubber drain that we slide into the brain for the purposes of draining off spinal fluid, we try to put our catheter in one of the lateral ventricles with the tip right at the forament of Monroe. Normally we do this in patients with hydrocephalus, who have scans that look more like this, with very large ventricles...

...which clearly provide a much easier target than I could shoot for with my patient. Under normal circumstances if we have to put a ventricular catheter in someone with ventricles that small, we use special computer-assisted image guidance to ensure that we can place the catheter appropriately.

My point here is that a ventriculostomy in this particular patient was to be no small task. In fact, it would be the sort of thing that a neurosurgery junior resident could brag about.

So here I am, it's 2:00 am, and I'm dealing with this extraordinarily sick patient who needs a catheter slid into his infinitesimal ventricles. So I run up to the neuro ICU, gather my supplies, and set up for a ventriculostomy. I talk to the family, and explain to their stunned and barely comprehending faces that their loved one is in exceptionally critical condition, and that this procedure, though unlikely to help, is the only thing we can offer that might make any difference to his neurologic outcome (this sort of glum prognostication is par for the course in neurosurgery).

After the family agrees to proceed, I hurry back into the patient's room, which has now collected a handful of interested onlookers. Usually we perform these procedures in our neuro ICU, where the placement of a ventriculostomy hardly garners a shrug, but in the ED its novelty usually attracts an audience of several techs, nurses, and residents.

I act fast, because I know that every second matters for this patient's already poor prognosis. I shave the scalp, mark out my landmarks on the skull, and tape the head to the bed to keep it still. Then I prep the skin and ready my supplies. After placing sterile drapes over the area, my first move is to confirm my landmarks (this is of utmost importance when the ventricles are small), and then slice a 2 cm opening in the scalp. The most nauseating move--for the onlookers, that is, the uninitiated--comes next, which is using a hand-held drill to (quite indelicately) drill a hold through the skull. After puncturing through the inner margin of skull you need to clean up all the errant bone chips, at which time the only thing separating you from the brain is a thick lining of connective tissue called the dura mater. This I puncture open, and now all that's left before I can relax is the passage of my rubber catheter into the slit-like ventricles six centimeters deep.

Any time I advance a catheter into the brain and pull out the stylet, I expect to hit paydirt with the first shot. I have to have that expectation--after all, this is somebody's brain. But sometimes you pull out the stylet and nothing comes out, and you drop the catheter down below the level of the ear to help the fluid flow out and still nothing comes, and you feel this sense of visceral free-fall as if you've just crested the top of a roller coaster and your gut knows you're sinking before your brain does. I hate that feeling. It's guilt and fear and shame and regret all rolled into one. So then you have the pull the catheter back out and reassess everything--your landmarks on the skull, your angle of approach, the size and position of the patient's ventricles--everything. Because you have to get it right the next time.

In this case, it took me a couple of passes to find this patient's very small ventricles. But I found them. Spinal fluid shot out of the catheter tip, with an opening pressure of 45 cm of water (measured according to the height of a fluid column). That's three times the upper limit of normal, and this despite the mannitol and the hyperventilation. That is, as we say in the business, bad.

But I nailed it. Not with the first pass, but I managed to pass a rubber catheter blindly into someone's head and hit a target about the size of a poker chip turned on its side. I should have felt proud. I should have bragged about how I managed to place an impossible ventriculostomy under less-than-perfect circumstances in the middle of the night. I should have printed out the patient's next head CT scan and run proudly around the department with it.

Except the patient didn't survive to have a second head CT scan. The ventriculostomy didn't help. So instead of a victory celebration, I had to explain to the family that their loved one continued, despite our best efforts, to have no sign of neurologic function.

Technical victory. But defeat in every way that matters.

3 Comments:

At 6:53 PM, Blogger phoenix said...

I just got home from vacation and I see that I have some catch up reading to do here. I will tomorrow I promise but I wanted you to know that I am sorry you have a defeat to mess up that victory dance you should have been able to take. It is never easy, but it is what makes us grow as people. Hugsssssss Ian.

 
At 7:49 AM, Blogger Ian said...

Thanks, Phoenix! I think you're the only one who reads my blog. Thanks for sticking with me!

 
At 1:35 AM, Blogger Unknown said...

Thank you for this post and it's very inspiring for me.
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