Other than the control of ICP and maintaining adequate cerebral perfusion pressure, there is no evidence that anything else affects outcome in TBI.
We have most control over the arterial pressure.
My goals are few and simple:
1. Check the pupils for a baseline.
2. Maintain an ICP below 20
- If there is no ICP monitor, and I suspect an elevated ICP, and if mannitol has not been given, I give 0.5 – 1 gm/kg
- Hypertonic saline is useful
- See post: https://trauma01.wordpress.com/2012/09/20/hyperosmolar-therapy-for-raised-intracranial-pressure-nejm/
- As an approximation, the following volumes of 3% NaCl are required to raise the serum Na concentration by 10 mmoles/liter (e.g., from 140 to 150):
Weight in Kg Volume of 3% NaCl needed 50 500 60 600 70 700 80 800 90 900 100 1000
Roughly 10 ml 3% NaCl per kg body weight. Give in 150 ml boluses.
3. Maintain a CPP of 50-70
- If there is no ICP monitor, I assume the ICP is 30 (could be higher)
- I maintain a CPP of 50-70 (with phenylephrine if necessary)
- MAP – (assumed ICP of 30) = CPP 50-70
- MAP needs to be 80-100!
- Even brief episodes of decreased MAP (CPP) worsens outcome
4. Maintain mild hypocarbia.
I do not worry about recall in these cases. I have yet to have a comatose patient complain about recall after regaining consciousness. I don’t normally deliver a vapor during these operations because they decrease MAP. I use vapors only to control HYPERTESION. If the MAP is good, I might dial in 0.4-0.5% isoforane.