A 42-year-old man with a history of insulin-dependent diabetes mellitus, hypertension, and end-stage renal disease on hemodialysis is admitted to the surgical ICU after a motor vehicle collision resulting in femur fracture and subdural hematoma. The patient is alert and oriented. His vital signs are:
His blood work is significant for:
The patient states that he missed a dialysis session two days ago and that he was on his way to the dialysis center when he had the car accident.
Which of the following dialysis modalities is INAPPROPRIATE for this patient?
A. Intermittent hemodialysis (iHD)Correct Answer: A
Intermittent hemodialysis (iHD) is associated with an increased risk of causing dialysis disequilibrium syndrome (DDS). DDS is characterized by different neurological symptoms of varying severity. Its symptoms range from nausea, headache, dizziness to seizure, coma, and death. DDS is primarily caused by fluid shifts that result in brain edema. Removal of urea across the blood-brain barrier occurs at a much slower rate than urea removal from plasma. This cause the brain cells to be “relatively” hyperosmolar to plasm and promotes water movement to brain cells.
Moreover, patients with end-stage renal disease are in a chronic hyperosmolar state; this leads to the development of “idiogenic osmoles,” which add to the “relative” hyperosmolarity of the brain following dialysis. It has been reported that brain volume increases by an average of 3% after hemodialysis, which makes iHD inappropriate for patients with head trauma, intracranial bleeding, stroke, or any intracranial pathology that leads to increased intracranial pressure.
The use of dialysis modality that removes solute and fluid at lower rates do not cause significant elevation of intracranial pressure and lower the risk for DDS. CRRT, SLED, and EDD can be used for patients at risk for DDS, and they all have similar effects on intracranial pressure and hemodynamics.
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