Just wanted to say what a remarkable bunch of fans you all are, and to wish you all a fantastic 2014!
I really need to get out and get stuff done, so I’ll post a more (this sounds SOOOOO ridiculous) ummmm . . . detailed analysis (ahem) of the presser when I’m back. Meanwhile, a synthesis. 4 main conclusions for me, for now:
- Michael is in VERY good hands. It doesn’t matter a hoot that this or that famous neurosurgeon and/or neurointensivist would or wouldn’t do this or that element of Michael’s treatment, the point is that these guys are smart, they’re talking to each other and to the family, and they seem technically up to the job. Oh and by the way, the decision to evacuate the second, intracerebral, hematoma seems to me, a non neurointensivist, to make sense. But more on this later.
- It sounds retrospectively that MichaeL’s ICP was worrisomely and persistently high yesterday, despite the right sided bone flap not having been closed. This was a standard and totally normal decision Sunday in the OR. The ICP problem was so worrisome that they considered a dip to be a “respite” allowing them to scoot to the scan. Now remember, I’m piecing this together from the words used, so everything I say is therefore subject to interpretation. But we’ve all had patients like this and agonised over going to the scan, coz until just before (the respite they’re talking about) every time we TOUCHED them their ICP shot up. So the decision was made to gain some room, and drain what sounds like superficial left-sided hematoma. These are usually left alone, and it had previously (and reasonably) been decided NOT to touch this one. But given the ICP problem, and that overall the brain was less “angry”, it was decided to evacuate it, especially as this meant leaving the left sided bone flap off.
- This leads me to insist on just how sick Michael was yesterday. These guys were sweating bullets, doing everything known to man to help, and they deserve a lot of credit. But this was SERIOUSLY life threatening minute to minute yesterday.
- Lastly, I think we can A) reset all the countdown clocks we started yesterday (time to reduce sedation, time to wean from vent, etc). And B) insist on just how severely Michael is injured. Be patient. This is gonna take a long time.
First off, this press conference was rather more reassuring than what I expected. I’ll admit that I feared an announcement of a second operation for persistently elevated intracranial pressure (ICP), and the fact that that’s not been needed is good.
So what do we know now? We know that besides keeping Michael deeply asleep, they’ve also slightly lowered his body temperature. This is part of the strategy to optimise the brain’s metabolic state. Along with increasing the delivery of “good stuff” to the brain, reducing the temperature reduces the brain’s need for stuff. Therefore the supply:consumption relation is rendered more favorable.
We’ve’ been told that Michael has bilateral lesions. This mean the brain is wounded in both hemispheres. That shouldn’t surprise us. This was a hard hit. What kind of “lesions”? While we haven’t been told exactly, we can assume a mix of three types. First, the hematoma itself. This is a collection of blood that can be evacuated. That’s been done, and Michael will be examined and scanned regularly in order to detect the formation of any new hematomas, or re-accumulation of the original one.
Next are contusions. These are basically black-and-blue marks in the brain. They result from blunt forces, and consist of areas of swelling and blood that’s seeped out of the vessels into the tissues – just like when you hit your arm. In the brain, as elsewhere, that blood gets absorbed, and the damage heals. Usually fine, but sometimes leaving small cavities behind.
The third type of lesions are at the microscopic level. They consist of damage to the bundles of “cables” (axons) connecting groups of brain cells. This type of damage isn’t readily visible using standard imaging, but is often associated with “poor neurological outcome”. These lesions aren’t treated specifically; rather, they are managed by classic neuro intensive care principles – maximise brain happiness and avoid brain unhappiness.
Hope this helps!
We’re all going to be hearing a lot about intracranial pressure over the next hours and days, so I thought it would be useful to understand a bit about it. Here we go.
The brain is enclosed in a rigid closed box. Since the volume of the box is fixed in adults, the addition of any extra “stuff” won’t take up more space, it’ll increase the pressure. What kind of “stuff”? Well in this case, at least yesterday, the extra stuff was a blood clot. This clot now has crammed itself into the same snug volume as the brain, kinda like when your kids jump into bed with you. The pressure goes up. Treatment is obvious – take out the clot!
Another “extra” element which can try to stuff itself into the skull is the brain itself. Remember that what we call the brain actuall contains three things: brain tissue, cerebrospinal fluid (or CSF), and the blood volume contained in the arteries, veins and capillaries of the brain. An abnormal increase in the volume of any of these “compartments” can, if big enough, lead to increased pressure. In Michael’s case, what we don’t want to have happen is to see the brain tissue itself swell. This would mean the brain cells themselves are not maintaining their volume, implying a severe level of injury. This kind of edema (swelling) is also harder to treat. Here, one attempts to optimise the flow of CSF and blood return to the heart by nursing the patient 30° head up. The brain needs to be properly perfumed with blood containing the right amounts of oxygen and glucose to maintain healthy cellular metabolism. If the pressure is much too high, the patient will be deeply sedated in order to protect the brain by decreasing its metabolic requirements. Lastly, the neurosurgeon can remove a large flap of skull bone. The “box” is now open, the pressure is now normal, and the swelling now expresses itself as a brain that is actually swollen without many of the deadly side effects of elevated ICP. This extreme measure, regularly carried out with severe head injury, is called a decompressive craniectomy.
Why is elevated intracranial pressure (ICP) bad?
There are at least 3 reasons. First is that elevated ICP means something bad has happened to the brain. This primary injury, whatever it is, has already done damage and that’s of concern. Second, this pressure acts to compress the blood vessels nourishing the brain. The higher the ICP, the worse the blood flow. So there’s a vicious circle: the ICP goes up, blood flow down. The cells suffer from lowered oxygen delivery and start to swell, making the ICP worse. Bad news. The third reason is mechanical. The brain is held in place in the skull by tough sheaths, between the hemispheres, and between the brain and the cerebellum. When the ICP goes much too high, it can actually force the brain to slide under one or the other of these partitions, usually with catastrophic consequences.
Hope this helps!