Week 50: Renal Failure

Although the patient’s examination is consistent with BPH (associated with increased rates in asymptomatic hematuria), he is also at risk for urologic malignancies and needs urgent referral to urology for further evaluation. His urinalysis and lack of symptoms rule out a urinary tract infection as a cause for the hematuria. If urolithiasis is suspected, a noncontrast CT scan should be ordered to confirm the diagnosis.

Diuresis in an already dehydrated and therefore pre-renal patient may lead to worsening renal function due to renal ischemia. A “trial of diuretics” is not generally advised and is not without risk to the patient. There is no compelling evidence that the combination of diuretics and dopamine helps to prevent progression to end-stage renal disease for oliguric acute renal failure patients. Therefore neither can be considered “routine” therapeutic interventions.

Peritonitis is a fairly common occurrence in patients maintained on CAPD. It is usually initially recognized when peritoneal fluid is noted to be cloudy at the time it is drained for a routine exchange. With prompt medical attention, including microbiologic evaluation of peritoneal fluid, patients can be treated with intraperitoneal antibiotics as outpatients after an initial intraperitoneal dose is given in the ED. The prognosis of uncomplicated peritonitis is generally excellent, and patients are typically asked to follow up in 2 days. Free air seen on abdominal plain film is most often due to air being introduced during a previous fluid exchange. CT scanning is not indicated unless there is severe abdominal pain and tenderness or other findings suggestive of perforation.

Vascular access infections are not uncommon in hemodialysis patients, and patients may present with fever alone, and no local or systemic findings. Although bacteremia is often found, endocarditis is unusual in the absence of prolonged or recurrent fever, or of the usual risk factors for infective endocarditis. The hemodialysis procedure itself rarely causes fever.

A 25-year-old man is brought from the hemodialysis unit because of hypotension that occurred during dialysis. His blood pressure is currently 94/60, pulse is 84, and he is afebrile. Physical examination is otherwise normal. An ECG is unchanged from a previous tracing. Which of the following is most accurate?

This patient is presenting with likely rhabdomyolysis. Rhabdomyolysis has numerous causes, and there are two prominent electrolyte disorders that may precipitate/predispose the patient to developing rhabdomyolysis: hypophosphatemia and hypokalemia. Hypophosphatemia and rhabdomyolysis has been associated in chronic alcoholics.

Rhabdomyolysis, once developed, is characterized by muscle necrosis, with the release of intracellular contents. Typical electrolyte sequelae seen as a consequence of rhabdomyolysis include hyperkalemia, hyperphosphatemia, hyperuricemia, and hypocalcemia.

This EKG shows wide-complex tachycardia. Given the history of end-stage renal disease on hemodialysis, and patient is likely due for hemodialysis, one must suspect hyperkalemia. When wide-complex tachycardia is secondary to hyperkalemia, the treatment is calcium to stabilize the myocardium.  Insulin and D50 may also be given, as well as kayexalate.  The definitive treatment will be dialysis but this patient must be stabilized. The other treatments of other causes of wide-complex tachycardia will not work in this condition.

The patient has nephritic syndrome which classically manifests as hypertension, azotemia, edema, and hematuria (with RBC casts). There are many causes, including post-streptococcal, systemic diseases, infections, drugs, and autoimmune. In this patient’s case, the recent URI suggests a post-streptococcal infection.  Further, the other answer choices are more likely to cause nephrotic syndrome, not nephritic syndrome.  Post-strep glomerulonephritis is thought to be caused by immune complex deposition.  Management is supportive care.

Minimal change disease is the most common cause of nephrotic syndrome in young children.  It can also occur in adults but is much less common. This patient’s red blood cell casts is more suggestive of a nephritic syndrome. Focal segmental glomerularsclerosis is a cause of kidney failure in children and adults.  In adults it accounts for 35 percent of all cases of nephrotic syndrome (50% among African American patients).  Classically it is associated with HIV infection.  This patient’s URI prior to symptom onset however is more suggestive of post-strep glomerulonephritis.  Further, the hematuria and red blood cell casts suggests a nephritic, not nephrotic syndrome.

This young woman presents with sudden-onset headache, and is hypertensive with renal insufficiency. One must consider polycystic kidney disease. In polycystic kidney disease, patients typically present with flank pain, hematuria, hypertension and renal insufficiency. In addition to cysts in the kidneys, patients may also develop liver cysts and cerebral aneurysm. In setting of a sudden-onset headache, a head CT should be obtained to evaluate for a ruptured aneurysm.

Generalized malaise, decreased urine output, and elevated creatinine level are suggestive of acute renal failure. There are three etiologies of renal failure: prerenal, intrinsic, and postrenal. In this case, patient is immunocompromised and is recently started on a medication for an infection, presumably an antiviral for CMV retinitis. Many antivirals and antiretrovirals are nephrotoxic, and cause intrinsic renal failure. In acute tubular necrosis (ATN), which is the most common form of intrinsic renal failure, fractional excretion of sodium is typically > 2%, with low urine osmolality due to the loss of concentrating ability of damaged tubules and impaired response to anti-diuretic hormone. Hyaline casts can be observed with concentrated urine, but generally are non-specific. Heme-granular casts, or “muddy brown” casts, are classically seen with ATN.