The Daily Mail has done it again. With today’s headline they’ve “forced” me to take to my blog to help clarify some of what’s being said.
As with everything that I’ve said, tweeted or written since Michael’s accident, I need to make clear that I have not seen Michael, not seen his scans, and not had any contact with the medical team caring for him. I’m going to base the following on what has been said by his care team, on the things that have not been said (by anyone), and on my clinical experience (and that of colleagues) with similarly injured patients.
What is likely happening now? Michael is almost certainly still in the Intensive Care Unit (ICU). I say this primarily because it is rather likely that he still requires this level of care given his injuries, but also because had he been moved from the ICU to a normal room, this would have been sufficiently newsworthy to have almost certainly been announced. If Michael’s breathing is still handled by a respirator, he will almost certainly have had a tracheostomy done. This is more comfortable for the patient, spares the patient from potential damage to the vocal cords, and can make weaning from the respirator easier. It can also be easily closed later, when appropriate.
More importantly is the question of the “artificial coma”. Now those of you who’ve been reading me since the beginning have no doubt noticed that I HATE the term “artificial coma”. It’s confusing and doesn’t transmit any useful information. Initially Michael was no doubt maintained at a VERY deep level of sedation, deep enough to virtually suppress most electric activity in the cerebral cortex (the outer layer of the brain, responsible for higher intellectual functioning). This was done to help manage what were extremely high and dangerous levels of intracranial pressure (ICP, see previous blog entries).
Now that the acute phase of the injury has largely passed, it is almost certain that ICP is no longer problematic. The swelling and bruising are being resorbed. This means that the sedation will certainly have been lightened. Remember that having a tube in the windpipe is a pretty significant and painful stimulus. So sedation is almost always needed to help the patient tolerate the tube, to allow mechanical ventilation, and permit all the other “aggressions” that are part of day-to-day ICU routine. If this is the case, then the care team will be repeatedly, and considerably, lightening the sedation, in order to start weaning Michael from the ventilator, and to allow neurologic evaluation.
This would be good – if the sedation is light, and if respiratory weaning (getting Michael to breathe by himself) is progressing, with a neurological status that allows this, then we can relax for a few weeks, and see how the situation evolves. This situation would mean progress has been made, and renders further prognostication impossible. Progress will continue at an unknown and unknowable speed, and will stop at an unknown and unknowable level of function.
It is also conceivable, at the other end of the “goodness” spectrum, that the sedation has been turned off, that Michael is tolerating the tube, but is neither breathing adequately on his own nor showing significant signs of emerging. You understand that tolerating a tube with no sedation implies rather severe problems with deep levels of the brain, as does the lack of adequate breathing despite stopping the sedatives. At three weeks post injury, this is the worst outcome we could hope for, as it would indicate a rather high probability that normal consciousness will not be regained.
A brief word about the terms “critical” and “stable”. First of all, as used with respect to the condition of hospitalised patients, neither is precisely defined. So it’s important to see them rather more like an impressionistic image than as an accurate statement of physiology. Critical means imminent life threat or threat to a vital system. Stable means that something is not changing, and is usually being maintained within normal limits. So Michael is no longer CRITICAL (the ICP has normalised), and STABLE, as his physiological parameters are now acceptably “constant”.
Ok let’s get down to the hard stuff here. What are the possible outcomes? I’ll look at some of them, mostly with an eye to defining terms we’re likely to see thrown about in the near future, so that we can be precise ourselves, and be critical when faced with imprecise, ambiguous, or misleading information from others (are you listening Daily Mail?).
Now remember, all we know with certainty about Michael’s injuries comes from the press conferences given by his care team. After explaining the how and why of evacuating the right-side extradural hematoma (on the Sunday) and then the left-sided intracerebral hematoma (on the Monday), the neurosurgeon let slip a VERY telling statement.
I’m almost quoting him here, translating from the French. He said “don’t think that we evacuated two hematomas and that’s it”. “Michael has lots of hematomas in his brain, on the left, on the right, and in the middle”.
Damn. See, the “middle” is where all the important stuff happens – awareness, arousal, control of blood pressure, respiration, swallowing etc. And the left – well that’s usually language. Etc etc. The neurosurgeon, intentionally or not, painted a rather catastrophic neurologic picture.
First off let me say that it is EXTREMELY unlikely (I’d honestly say virtually impossible) that the Michael we knew prior to this fall will ever be back.
I think that it will have to be considered to be a triumph of human physical resiliency, and of modern neurointensive care, if Michael is able to walk, feed himself, dress himself, and if he retains significant elements of his previous personality. If recovery proceeds to this point (which is totally POSSIBLE, if perhaps rather improbable), it is an open question as to how well the “higher functions” (memory, concentration, reading, planning, etc) will recover. Please note, I would love to be proven wrong about this!
At the other end of the spectrum would be continued coma. Coma is defined as a state where there is neither wakefulness nor awareness (the patient cannot be woken by stimuli), no meaningful interaction with the environment, and no voluntary actions. This is obviously catastrophic. This outcome is entirely possible based on what we know about the brain’s primary injuries (the fall, the hematomas, bruises, etc) as well as the relatively long period with high ICP.
It happens that patients in coma emerge sufficiently to show spontaneous eye-opening, and even sleep-wake cycles (demonstrating wakefulness or arousal), but show no interaction with the environment, and no signs of any higher function (thought, speech, etc). This is called a vegetative state. Definitions vary somewhat, but usually after four weeks it is termed a persistent vegetative state, and after one year it is called a permanent vegetative state. Very roughly speaking, about 50% of head trauma patients who are in a vegetative state one month after injury become conscious, often with significant neurologic impairment. If the vegetative state persists for six months, this falls to roughly 20%, usually with severe impairment. After one year, resumption of normal consciousness is very rare, and, when it happens, function is usually gravely altered.
Whereas a patient in a vegetative state shows no signs of awareness, a patient in a minimally conscious state will show definite signs of awareness of either self and/or of the environment. This may include obeying simple orders, some intelligible language use, or other behaviors that seem “goal directed”. Examples would be appropriate emotional responses, appropriate eye tracking, consistent and appropriate movement or vocalisation in response to language (not just sounds). These signs usually fluctuate through the day, and over time. Importantly, the chances of meaningful recovery from a minimally conscious state are higher than from a vegetative state. They are however, still disappointingly low.
There is certainly reason for worry – lot’s of worry. But no reason to lose hope. Everyone who works with head-injured patients has seen VERY severely injured patients (who were not expected to do well) recover acceptably. All we can do is wait, pray, and be behind Michael and his loved ones.
A Former F1 Doc Writes 