Acute Renal Failure (ARF)
Acute Renal Failure (ARF)-
Chronic kidney disease- develops slowly over months to years and necessitates the initiation of dialysis or transplantation. Chronic kidney disease is not a critical care issue. Although it is seen regularly in an ICU setting, it is generally not the reason for admission to the ICU.
Acute renal failure (ARF) -is a clinical syndrome characterized by rapid decline in renal function → progressive azotemia and increase ↑creatinine. It is associated with oliguria which can progress over hours or days with in increase↑ BUN, creatinine, and K+ with or without oliguria.
The 3 types of acute renal failure include:
- Prerenal failure- Caused by conditions such as hemorrhage, myocardial infarction, heart failure, cardiogenic shock, sepsis, and anaphylaxis → impaired blood flow to kidneys → hypoperfusion of kidneys → retention of excessive amount of nitrogenous compounds → intense vasoconstriction →↓glomerular filtration rate (GFR). Patient can recover if fluid is replaced.
- Intrarenal failure-Caused by burns, crush injuries, infections, glomerulonephritis, lupus erythematosus, diabetes mellitus, malignant HTN, nephroseptic agents → acute tubular necrosis → afferent arteriole vasoconstriction → hypoperfusion of the glomerular apparatus →↓GFR → obstruction of tubular lumen by debris and casts, interstitial edema, or release of intrarenal vasoactive substances. A nonrecovery is common.
- Postrenal failure- Caused by any obstruction such as bladder tumors, renal calculi, enlarged prostate, or blocked catheter between the kidneys and urethral meatus →↑ pressure in kidney tubules →↓GFR.
ARF presents as-
- Critical illness
- Persistent nausea and vomiting
- Dry skin and mucous membrane from dehydration
- Muscle twitching
Signs of ARF include: -
- Urine <400 mL/24 hours
- ↑Serum urea and creatinine
- Peripheral and systemic edema
- ↓ BP → fluid overload → pulmonary and peripheral edema
- ↓ BP → dehydration/sepsis
- Abnormal, irregular pulse → cardiac arrhythmia
- Kussmaul’s respirations → metabolic acidosis
- ↑Temperature → infection
- ↓ level of consciousness (LOC)/seizures
- Electrolyte imbalance (increased serum BUN, creatinine, K+, Na+, phosphate; decreased serum calcium)
- Serum BUN, creatinine, electrolytes, CBC, coagulation studies (PT/PTT), serum osmolarity, chemistry panel
- Urinalysis with microscopic examination for protein and casts
- Urine culture and sensitivity
- Urine electrolytes and urine osmolarity
- 24-hour urine for creatinine clearance
- Renal ultrasound scanning
- Chest x-ray
- Renal biopsy
- GFR rate
- Kidney-ureters-bladder (KUB) x-ray
- Intravenous pyelogram (IVP)
- CT scan or MRI of kidneys
- Renal arteriogram
- Monitor fluid and electrolytes. Assess for acid-base imbalances.
- Assess respiratory status and monitor oxygenation. Administer O2 as indicated.
- Institute cardiac monitor and observe for arrhythmias.
- Insert indwelling Foley catheter.
- Restrict fluid intake and measure intake and output strictly. Assess for edema.
- Assess color, clarity, and amount of urine output. Check specific gravity.
- Institute renal diet with adequate protein and low K+, Na+, and phosphorus. Protein may be restricted if BUN and creatinine greatly elevated. Treat anorexia, nausea, and vomiting.
- Monitor daily weight.
- Insertion of a large-bore central line.
- Administer medications, including calcium channel blockers, beta blockers, and diuretics such as bumetanide (Bumex) and furosemide (Lasix).
- Administer iron supplement.
- Monitor hemoglobin and hematocrit levels for anemia and O2-carrying capacity of hemoglobin.
- Administer blood products or erythropoietin products as needed.
- Maintain meticulous skin care to prevent skin breakdown.
- Ensure prevention of secondary infections.
- Assess for gastrointestinal and cutaneous bleeding.
- Assess neurological status for changes in LOC and confusion.
- Administer dialysis (hemodialysis, peritoneal dialysis).
- Provide patient and family support.