A 22-year-old patient is admitted with an acute traumatic brain injury with raised intracranial pressure. They also have a severe acute kidney injury requiring renal replacement therapy (RRT). Outline the potential issues of providing RRT, including your management of the issues
Not available.
This question is a reworded version of Question 21 from the first paper of 2018, which means readers can go there to see what the official college answer would likely have been.
| Domain | Recommendations | Rationale |
| Access | Avoid internal jugular lines | Promote venous drainage from the brain |
| Modality | Prefer CRRT | Produces a more gradual solute clearance; less likely to produce cerebral oedema |
| Low efficiency IHD/SLED | ||
| Frequency | Daily, if not continuous | Daily treatments decrease the fluctuations of urea |
| Blood flow | Start low, increase slowly | Minimise haemodynamic effects |
| Dialysate flow | Start low, increase slowly | Minimise solute clearance |
| Dose | Under-dialyse (by half) | Minimise solute clearance per unit time |
| Solute clearance | Pre-dilution haemofiltration | Minimise urea clearance: decrease the resulting urea gradient between brain parenchyma and blood, minimising cerebral oedema |
| Filtration | Low volume fluid removal | Minimise dialysis-associated hypotension to prevent cerebral hypoperfusion |
| Anticoagulation | Regional, or none | Prevent cerebral haemorrhage extension due to anticoagulation. Minimal anticoagulation is recommended for 2 weeks following TBI. |
| Dialysate | Add sodium | Minimise the hyponatremia which develops due to exposure to hyponatremic dialysate (to keep sodium around 145-150 mmol/L) |
| Add urea | Minimise urea clearance | |
| Minimise bicarbonate | Prevent intracellular acidosis (may be hypthetical) | |
| Fluid warmer | Temperature matching | Maintain therapeutic hypothermia if this is being used for ICP control |
Davenport, Andrew. "Renal replacement therapy in the patient with acute brain injury." American journal of kidney diseases37.3 (2001): 457-466.
Davenport, Andrew. "Renal replacement therapy for the patient with acute traumatic brain injury and severe acute kidney injury." Acute Kidney Injury. Vol. 156. Karger Publishers, 2007. 333-339.
Davenport, Andrew. "Practical guidance for dialyzing a hemodialysis patient following acute brain injury." Hemodialysis International 12.3 (2008): 307-312.
Yeh, Shih-Hao, Chen-Yu Wang, and Chien-Min Lin. "Preventing intracranial pressure fluctuation in severe traumatic brain injury during hemodialysis." Journal of Medical Sciences 36.4 (2016): 152.