Uremic encephalopathy: Clinical sciences

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Introduction0:00–0:46

Uremic encephalopathy is a metabolic disorder characterized by progressive neurological dysfunction. Now, this typically occurs in the setting of acute kidney injury or AKI, progression of chronic kidney disease or CKD, or under dialysis.Normally, the kidneys are in charge of cleaning our bodies by excreting toxins like urea into the urine.
If our kidneys don’t function properly, these toxins can accumulate in the blood and eventually in the central nervous system, leading to progressive dysfunction, which can present with a wide range of neurologic symptoms, ranging from mild confusion and altered mental status to even coma.Now, if your patient presents with a chief concern suggesting uremic encephalopathy, you should first perform an ABCDE assessment to determine if they are unstable or stable.

Unstable Patient0:46–1:36

Patients with uremic encephalopathy generally present as unstable, so immediately begin acute management! Stabilize the airway, breathing, and circulation.
This means you might need to intubate the patient. Next, obtain IV access, and if your patient does not already have dialysis access, you’ll need to emergently place a dialysis catheter as well.
Also, don’t forget to put your patient on continuous vital sign monitoring including heart rate, blood pressure, and pulse oximetry, as well as cardiac telemetry.
Finally, if needed, provide supplemental oxygen.Okay, now that you’ve stabilized your patient, let’s look at your next step.

History and Physical 1:36–3:36

Start with obtaining a focused history and physical examination. You should also order labs like CMP and ABG, as well as a 12-lead ECG, and a chest X-ray.
The history will typically reveal mental status changes like confusion and lethargy, as well as other symptoms of uremia, such as muscle cramps and itching.
Additionally, the physical exam may reveal disorientation, impaired attention, and even hallucinations, but also tremor and asterixis.
In extreme cases, your patient might experience seizures or even a coma.On the flip side, labs will typically show elevated blood urea nitrogen or BUN, and creatinine, and may also reveal electrolyte imbalance including hyperkalemia, and an acid-base disorder, most commonly metabolic acidosis.
Keep in mind that these lab findings can also be seen in individuals with kidney failure without uremic encephalopathy! Next, ECG findings typically correlate with the degree of hyperkalemia.
The earliest change you’ll see is tall-peaked T waves, followed by P wave flattening, and prolongation of the PR interval.
In severe cases, you might even see the disappearance of P waves, the widening of the QRS complex, and the eventual development of a sine-wave appearance.
Finally, the chest x-ray might reveal pulmonary edema, which typically occurs as a result of fluid overload.At this point you can diagnose uremic encephalopathy!
But, keep in mind that you should always rule out other conditions that can cause mental status changes, such as sepsis, metabolic disorders, as well as intoxication or withdrawal.Now, once you diagnose uremic encephalopathy, proceed with treatment.

Urgent Dialysis3:36–5:19

This involves urgent hemodialysis, which is the most effective method to rapidly eliminate the accumulated toxins. It also helps address any related hyperkalemia, metabolic acidosis, and volume overload at the same time.
Here’s a high-yield fact! You can easily remember the indications for urgent dialysis with the mnemonic AEIOU, which stands for Acidosis; Electrolytes, principally hyperkalemia; Ingestion or overdose of medications or drugs; Overload of fluid causing heart failure; and Uremia leading to encephalitis or pericarditis.And now a clinical pearl to keep in mind!
Hemodialysis is a form of kidney replacement therapy where blood is removed from the patient’s body and filtered by a machine that removes toxic metabolites and excess body water.
This machine also replenishes electrolytes and buffers, like bicarbonate, and then sends the blood back to the patient. Keep in mind that your patient requires a temporary access catheter to handle this large amount of blood volume!
But, if you anticipate long-term dialysis, you should establish permanent dialysis access, which includes the surgical placement of either an arteriovenous fistula, arteriovenous graft, or a peritoneal dialysis catheter.
These are not practical for urgent manifestations of uremia, like encephalopathy or hyperkalemia, since they must heal for several weeks before you can use them to filter out the patient’s blood!Now, once your patient has been dialyzed, your next step is to assess for the underlying cause of uremic encephalopathy.

Underlying Cause: AKI5:19–6:01

If there’s no known history of kidney disease, but your patient presents with a prerenal cause of acute kidney injury, like hypovolemia; an intrarenal cause, such as exposure to nephrotoxic medications or contrast media; or a postrenal cause, like obstructive uropathy, diagnose acute kidney injury as what’s causing the uremic encephalopathy.
Once you diagnose it, treat the underlying cause. On the other hand, your patient might have a known history of chronic kidney disease, such as diabetic or hypertensive nephropathy.

Underlying Cause: CKD progression6:01–6:36

In this case, you can diagnose uremic encephalopathy due to progression of their chronic kidney disease. The management primarily relies on long-term dialysis, which requires permanent dialysis access, such as an arteriovenous fistula or peritoneal catheter.
Additionally, consult your surgery team for possible kidney transplantation.Finally, patients with known end-stage kidney disease who are already on long-term dialysis can sometimes present with uremic encephalopathy.

Underlying Cause: Underdialysis6:36–7:20

This is most commonly due to underdialysis from missed dialysis sessions or a change in the patient’s metabolic requirements.
If history reveals missed or prematurely-ended dialysis sessions, then work with your patient on addressing any barriers they may have.
On the other hand, if history reveals the patient is attending dialysis as prescribed, optimize their dialysis settings.
Additionally, consider consulting your surgery team for possible kidney transplantation.Alright, as a quick recap… Uremic encephalopathy is a metabolic disorder characterized by progressive neurological dysfunction.

Review7:20–8:31

Patients are generally unstable, so initiate acute management, including stabilization of the airway, breathing, and circulation; continuous cardiac telemetry and vital signs monitoring; and obtain dialysis access.
Next, obtain a focused H&P and labs, and if your patient has altered mental status in the setting of elevated BUN and creatinine, diagnose uremic encephalopathy.
Next, begin urgent hemodialysis. After your patient has been dialyzed, assess for an underlying cause of uremic encephalopathy.
If the patient has acute kidney injury, treat the underlying cause of the injury. On the flip side, if they have a progression of chronic kidney disease, initiate long-term dialysis, and consider consulting the surgery team for a kidney transplantation.
Lastly, if they are underdialyzed, then addressing any barriers, optimize their dialysis settings, and consider surgical consultation for a