eMedicine Specialties > Emergency Medicine > Genitourinary

Renal Failure, Acute: Treatment & Medication

Author: Peter R Peacock Jr, MD, Director of Information and Systems, Department of Emergency Medicine, Kings County Hospital; Informatics Director, EM Physicians of Brooklyn
Coauthor(s): Richard H Sinert, DO, Associate Professor of Emergency Medicine, Clinical Assistant Professor of Medicine, Research Director, State University of New York College of Medicine; Consulting Staff, Department of Emergency Medicine, Kings County Hospital Center
Contributor Information and Disclosures

Updated: Aug 8, 2008

Treatment

Prehospital Care

Stabilize acute life-threatening conditions and initiate supportive therapy. Watch for electrocardiographic evidence of hyperkalemia. 

Emergency Department Care

Treatment of acute renal failure (ARF) ideally should begin before the diagnosis of ARF is firmly established. A high index of suspicion often is necessary to diagnose early ARF. Significant decreases in GFR frequently occur before indirect measures of GFR reveal a problem. All seriously ill medical patients (eg, elderly patients, diabetic patients, hypovolemic patients) should have ARF included early in their differential diagnosis.

• Physicians can play a pivotal role in reversing many of the underlying causes and preventing further iatrogenic renal injury if ARF is recognized early. After providing an adequate airway and ventilation, focus on fluid management of the patient with ARF.
• Fluid management
  • Patients with ARF represent challenging fluid management problems.
  • Hypovolemia potentiates and exacerbates all forms of ARF.
  • Reversal of hypovolemia by rapid fluid infusion often is sufficient to treat many forms of ARF. However, rapid fluid infusion can result in life-threatening fluid overload in patients with ARF.
  • Accurate determination of a patient's volume status is essential and may require invasive hemodynamic monitoring if physical examination and laboratory results do not lead to a definite conclusion.
  • Bedside sonographic evaluation including IVC measurement may give additional useful information.
• Urinary catheter placement
  • Urinary obstruction often is an easily reversible cause of ARF.
  • Placement of a urinary catheter early in the workup of a patient with ARF not only allows diagnosis and treatment of urethral and bladder outlet urinary obstruction but also allows for accurate measurement of urine output.
  • If available, bedside ultrasonography can quickly identify a large and distended bladder.
  • Routine use of urinary catheters should be tempered by consideration of their inherent risks of introducing infections.
• Renal replacement therapy
  • The principal methods of renal replacement therapy (RRT) are intermittent hemodialysis (IHD), continuous venovenous hemodiafiltration (CVVHD), and peritoneal dialysis (PD). Each has advantages and limitations.
  • IHD is widely available, has only moderate technical difficulty, and is the most efficient way of removing a volume or solute from the vascular compartment quickly. Unfortunately, dialysis-associated hypotension may adversely affect remaining renal function, particularly in patients who are hemodynamically unstable. This is one reason CVVHD is widely recommended in this setting.
  • Continuous RRT techniques are more expensive, associated with increased bleeding risk and not universally available; however, in addition to avoiding hypotension, they are believed to achieve better control of uremia and clearance of solute from the extravascular compartment. CVVHD may also preserve cerebral perfusion pressure more effectively. Although several studies have sought to directly compare CVVHD to IHD, no study has shown a convincing advantage for one therapy over the other.
  • Peritoneal dialysis is inexpensive, widely available, and does not result in hypotension. However, it is not capable of removing large volumes of fluid or solute. Its use may be most common in children and in developing countries.
  • Indications for and timing of initiation of RRT are also important and somewhat controversial subjects. Widely accepted indications for initiation of RRT include the following:
    • Volume overload
    • Hyperkalemia (K⁺ >6.5 or rising)
    • Acid-base imbalance
    • Symptomatic uremia (pericarditis, encephalopathy, bleeding dyscrasia, nausea, vomiting, pruritus)
    • Uremia (BUN >100)
    • Dialyzable intoxications
  • Severe dysnatremia (<115 or >165), and dysthermia may also be appropriate indications for RRT.
  • Significant intoxications with a dialyzable agent (eg, methanol, ethylene glycol, theophylline, aspirin, lithium) may be the strongest single indication for emergent dialysis because other effective therapeutic interventions are available for most of other complications of ARF. Volume overload can be treated with nitrates and phlebotomy; hyperkalemia can be treated with calcium, insulin, glucose, bicarbonate, binding resins, and beta-agonists.
  • The timing of initiation of RRT in the absence of these indications is controversial, although the consensus that RRT itself contributes to the resolution of ARF may be growing.
  • Intensity of RRT is another area of active controversy and research; some studies suggest that more is better. In a study of CVVH intensity in which patients with ARF were randomly given standard or supernormal levels of ultrafiltration, the patients with more intense RRT had significantly lower mortality rates. A second randomized trial compared daily IHD with traditional every-other-day IHD in patients with ARF and found that the mortality rate (28% vs 46%) and speed of renal recovery (9 d vs 16 d) were significantly improved. However, before these studies, no significant evidence indicated that increased dialysis dosage improved outcomes.

Consultations

Consider consultation with a nephrologist or critical care specialist in patients with newly diagnosed ARF.

Medication

Diuretics and vasodilators are used commonly to treat ARF. Unfortunately, in large randomized studies, these agents have failed to prove effective.

Atrial natriuretic factor also has been tested in a randomized double-blind study in ARF but failed to improve the course of ARF.

Calcium channel blockers have been shown in animal models to be protective in ARF if given before renal insult. Their only benefit in humans is preventing ARF in renal transplant patients receiving cyclosporine.

Infusion of mannitol is reported to be protective of myoglobinuric ARF if given within 6 hours of rhabdomyolysis. In addition, mannitol infusion has been shown to decrease the rate of ARF if given before cardiothoracic surgery and radiocontrast agents. No controlled studies have shown any benefit to mannitol infusion in patients with established ARF. In fact, mannitol given in high doses has been associated with ARF. Significant risks of prescribing large doses of mannitol to patients with ARF include fluid overload and hyperkalemia.

Renal Vasodilator

Fenoldopam is a potent dopamine A-1 receptor agonist that increases blood flow to the renal cortex and outer medulla and evidence to date suggests that it reduces mortality and provides renal protection in critically ill patients with or at risk of renal failure. Because it is titratable and it reliably controls severe hypertension, fenoldopam may be ideal for treating hypertensive emergencies where the affected end organ is the kidneys. 

Fenoldopam (Corlopam)

Selective postsynaptic dopamine agonist (1-receptors), which exerts hypotensive effects by decreasing peripheral vasculature resistance with increased renal blood flow, diuresis, and natriuresis.
In patients with renal insufficiency, fenoldopam provides an alternative to nitroprusside without the threat of cyanide and thiocyanate toxicity. Permits precise titration to the desired blood pressure level. Studies demonstrate safety of administration without invasive monitoring; however, clinician may choose invasive monitoring because fenoldopam causes rapid blood pressure changes.

Diuretics

Patients with nonoliguric (rather than oliguric) ARF have better mortality and renal recovery rates, prompting many to recommend diuretics in oliguric ARF. Unfortunately, randomized double-blind controlled trials fail to show benefit. Studies conclude that diuretics are useful only in management of fluid-overloaded patients and venodilators and dialysis are more effective interventions for this indication.

Furosemide (Lasix)

Increases excretion of water by interfering with chloride-binding cotransport system, which, in turn, inhibits sodium and chloride reabsorption in ascending loop of Henle and distal renal tubule. Also is potent vasodilator of medullary vessels, serving to wash out concentration gradient of countercurrent system, resulting in marked diuresis.

Vasodilators

Renal vascular vasodilators in ARF make a great deal of sense from theoretical and experimental viewpoints. However, effective blood-volume restoration is the best physiologic vasodilator.

Low-dose dopamine is a potent vasodilator, increasing RBF in ARF. Unfortunately, most clinical studies fail to show that it improves recovery or mortality rates. In the majority of ARF studies, dopamine was associated only with an increase in urine output. Current recommendations for dopamine favor its use in patients with ARF and concomitant hypodynamic heart failure. Balance benefits of diuretic action with proarrhythmic side effects.

Dopamine (Intropin)

Stimulates both adrenergic and dopaminergic receptors. Hemodynamic effect depends on dose; lower doses stimulate mainly dopaminergic receptors that produce renal and mesenteric vasodilation; cardiac stimulation and renal vasodilation produced by higher doses.
After initiating therapy, dose may be increased by 1-4 mcg/kg/min q10-30min until satisfactory response attained; maintenance doses <20 mcg/kg/min usually satisfactory for 50% of patients treated.

• Search for CME/CE on This Topic »

• Acute Tubular Necrosis (Pediatrics: General Medicine)
• Acute Tubular Necrosis (Nephrology)
• Acute Renal Failure (Nephrology)
• Hemorrhagic Fever With Renal Failure Syndrome (Pediatrics: General Medicine)

• Acute Kidney Failure Overview
• Acute Kidney Failure Treatment
• Diabetes Center
• Acute Kidney Failure Causes
• Acute Kidney Failure Symptoms

• Acute Kidney Injury Impacts Liver Transplantation Outcome
• Higher-Intensity Continuous Renal Replacement May Not Reduce Mortality Risk From Acute Kidney Injury
• WCN 2009: Biomarker Allows Early Diagnosis of Acute Kidney Injury

• Novel Biomarkers in Early Diagnosis of Acute Myocardial Infarction Compared With Cardiac Troponin T
• Determinants of Postoperative Acute Kidney Injury
• The Risk of Acute Renal Failure in Patients with Chronic Kidney Disease

• Acute Leukemia Resource Center
• Pancreatitis Resource Center
• Prostatitis Resource Center

• Depressive and acute manic episodes in bipolar disorder