Manage UsersNCLEX Study Guide


Renal system


Member since: April 2011
(Boynton Beach,FL)

Normally, kidneys excrete approx 1 ml of urine per kg of body weight per hr, which is about 1-2 l in a 24-hr period for adults.
There are 3 phases of acute renal failure:  oliguric, diuretic, recovery.
Oliguric phase

  • Increased BUN and creatinine
  • Hyperkalemia, hyponatremia, acidosis, hypervolemic, urine specific gravity >1.020

Diuretic phase

  • Hypovolemia
  • Hypokalemia, hyponatremia, low urine specific gravity <1.020

Some persons in ARF may not experience the oliguric phase but may progress directly to the diuretic phase, during which the urine output may be as much as to L/day.

Kayexalate may be prescribed if K is too high.

Body weight is a good indicator of fluid retention and renal status.

Excess fluid volume:

  • Dyspnea
  • Tachycardia
  • JVD
  • Peripheral edema
  • Pulmonary edema

Fluid deficient volume:

  • Decreased urine output
  • Reduction in body weight
  • Decreased skin turgor
  • Dry mucous membranes
  • Hypotension
  • Tachycardia

Watch for signs of hyperkalemia: dizziness, weakness, cardiac irregularities, muscle cramps, diarrhea, and nausea. Potassium containing foods – bananas, avocados, spinach, fish, and salt substitutes.

Clients with renal failure retain sodium.  With water retention, the sodium becomes diluted and serum levels may appear near normal.  With excessive water retention, the sodium levels appear decreased (dilutional).  Limit fluid and sodium intake in AARF clients.

During oliguric phase, minimize protein breakdown and prevent rise in Bun by limiting protein intake.  When BUN and creatinine return to normal, ARF is determined to be resolved.

Chronic renal failure: end stage renal disease

Accumulation of waste products form protein metabolism is the primary cause of uremia.  Protein must be restricted in CRF clients.  However, if protein intake is inadequate, a negative nitrogen balance occurs, causing muscle wasting.  The GFR is most often used as an indicator of the level of protein consumption.

Encourage protein intake to be of high biological value – eggs, milk, meat, because the client is on a low-protein diet.

Dialysis covered by Medicare.

The major difference bt dialysate for hemodialysis and peritoneal dialysis is the amt of glucose.  Peritoneal dialysate is much higher in glucose.  For this reason, if the dialysate is left in the peritoneal cavity too long, hyperglycemia may occur.

Administer aluminum hydroxide antacids to bind phosphates because client is unable to excrete phosphates (no magnesium based antacids).

As kidneys fail, meds must be adjusted.  Digoxin toxicity bc digitalis preparations are excreted by the kidneys.  Signs of toxicity in adults include nausea, vomiting, anorexia, visual disturbances, restlessness, headache, cardiac arrhythmias, and pulse <60.

Location of pain can help to determine the location of stones.

  • Flank pain usually means the stone in the kidney or upper ureter.  If the pain radiated to the abd or scrotum, the stone is likely to be in the ureter or bladder.
  • Excruciating, spastic-type pain is called colic.
  • During kidney stone attacks, it is preferable to administer pain medications at regularly scheduled intervals rather than PRN to prevent spasm and optimizing comfort.
  • Strain all urine.

Maintain high fluid intake 3-4 L/d and follow prescribed diet rt composition of stone.

Bladder spasms frequently occur after TURP.  Inform the client that the presence of the oversized balloon on the catheter will cause a continuous feeling of needing to void.  The client should not try to void around the catheter bc this can precipitate bladder spasms.

Use only sterile saline for bladder irrigation after TURP bc the irrigation must be isotonic to prevent fluid and electrolyte imbalance.

Inform the client prior to discharge that some bleeding is expected after TURP.  Large amounts of blood or frank bright bleeding should be reported.  However, it is normal for the client to pass small amounts of blood during the healing process as well as small clots.  He should rest quietly and continue drinking large amounts of fluid.

After TURP avoid strenuous activity, lifting, intercourse, and engaging in sports during the first 3-4 wks after surgery.