Critical Care Medicine-Neurologic Disorders>>>>>Encephalopathy and Delirium
Question 4#

A 69-year-old woman with type 2 diabetes has been diagnosed with diabetic nephropathy. If her disease continues to progress to endstage kidney disease, which of the following neurologic findings is most likely to lead to initiation of renal replacement therapy in this patient.

a. Acute-onset right hemiplegia
b. Glove-pattern paresthesia of upper extremities
c. Overt uremic encephalopathy presenting with seizures
d. Memory impairment and diminished ability to concentrate
e. Stupor progressing to coma

Correct Answer is D

Comment:

Correct Answer: D

In a patient with chronic kidney disease, progressive slow cognitive decline is more likely to lead to initiation of renal replacement therapy than overt uremic encephalopathy. There is a trend toward early initiation of renal replacement therapy at higher levels of kidney function, even though results of a large trial (IDEAL) did not support such an approach. Thus, chronic kidney disease patients are likely to start renal replacement therapy long before they develop life-threatening symptoms such as overt encephalopathy. Overt uremic encephalopathy typically develops in patients with estimated glomerular filtration rate of <5 mL/min/1.73 m2 and presents with severe cognitive impairment such as confusion, stupor, coma, or seizures (Answers C and E). The proposed mechanism for development of uremic seizures is activation of excitatory (NMDA) and inhibition of inhibitory (GABA) receptors.

The severity of uremic encephalopathy likely depends on the rate of renal function loss—encephalopathy may be more severe in acute kidney injury compared to chronic kidney disease. However, in patients with acute kidney injury, renal replacement therapy is likely to be initiated before development of overt encephalopathy for other clinical indications such as severe acidosis (pH < 7.1), diuresis-refractory volume overload, or hyperkalemia. Of note, a meta-analysis of studies comparing early versus late initiation of renal replacement therapy did not find the early initiation to be beneficial, although most of the included studies were described as low quality. 

Answers A and B are not consistent with typical presentation of uremic encephalopathy and should not lead to initiation of renal replacement therapy.

References:

  1. Stevens PE, Levin A; Kidney disease: improving global outcomes chronic kidney disease guideline development work group members. Evaluation and management of chronic kidney disease. Synopsis of the kidney disease: Improving global outcomes 2012 clinical practice guideline. Ann Intern Med. 2013;158:825-830.
  2. Seifter JL, Samuels MA. Uremic encephalopathy and other brain disorders associated with renal failure. Semin Neurol. 2011;31:139-143.
  3. Cooper BA, Branley P, Bulfone L, et al. A randomized, controlled trial of early versus late initiation of dialysis. N Engl J Med. 2010;363:609-619.