Medical Management of Acute Renal Failure - Essay Example

?Acute Renal Failure Acute renal failure (ARF), also known as acute kidney injury is defined as sudden decline in the renal filtration function. It is marked by rise in serum creatinine or by rise in blood urea nitrogen or both. These parameters, however, may be raised after some time. The only prominent sign of acute renal failure is decreased production of urine. There are basically 3 types of ARF and they are: prerenal, intrinsic and post renal. In prerenal, the nephrons are structural intact and ARF occurs because of adaptive response to volume depletion that is severe enough to cause hypotension. In intrinsic or renal type, structural and functional damage of nephrons occurs due to inflammatory, cytotoxic or inflammatory insults to the kidney. In postrenal kidney injury, there is obstruction to passage of urine. Acute renal failure can be oliguric or nonoliguric. In the former type, the daily urine volume is less than 400ml/day. The prognosis in this type is usually poor except in prerenal cases. Urine output of less than 100ml per day is anuria and occurs when there is bilateral obstruction or injury to both kidneys (Workeneh, and Batuman, 2011). 2. Tests useful in the management of acute renal failure are serum biochemistries, complete blood picture, urine analysis and urine electrolytes. Ultrasonography is useful is ascertaining the cause of renal failure, especially if the failure is due to obstruction. The hallmarks of acute renal failure are serum creatinine and blood urea nitrogen , both of which are elevated. However, the levels of these substances and the rate of rise depend on the degree of insult to kidneys. It is important to ascertain the ratio of BUN to creatinine. When the ratio is 20:1, is suggests enhanced absorption of urea, suggesting prerenal injury. BUN may be elevated in other conditions like gastrointestinal bleeding, steroid administration and loading of proteins. rise of serum creatinine by more than 1.5mg/dL/d warrants evaluation for rhabdomyolysis. Complete blood picture provides an overview of the anemia and leukocytosis. Peripheral smear shows schistocytes in conditions like hemolytic uremic syndrome. Increased formation of rouleax is suggestive of myeloma and the workup must be directed towards serum and urine immunophoresis. Other tests which help in detecting the etiology are presence of free hemoglobin, free myoglobin, increased levels of serum uric acid, serological tests like antinuclear antibody, antistreptolysin antibody and serum complement levels. Urine analysis is a very useful investigatory tool. In tubular necrosis, granular muddy brown casts will be seen. In some cases tubular cast cells or oxalate crystals may be seen. Cola colored urine or reddish brown urine is suggestive of hemoglobin. Presence of significant proteinuria is suggestive of tubular injury. Presence of red blood cells in urine is suggestive of inflammation of glomerulus or bleeding in the collecting system. Presence of white blood cells or their casts in urine is suggestive of acute interstitial nephritis or pyelonephritis. Presence of eosinophils indicates allergic interstitial nephritis (Schrier, 2004). There are basically 3 stages of acute renal failure and they are oliguric-anuric phase, early diuretic phase and late diuretic phase. In the oliguric-anuric phase, the urine output is less than 400 ml/day. There is electrolyte imbalance, metabolic acidosis and raised serum creatinine and blood urea nitrogen. The phase lasts for about 14 days. In the early diuretic phase, the patient passes large volumes of urine, about more than 3000ml per day. This is because; the glomeruli are functioning but the tubules are not. The tests reveal electrolyte imbalance, metabolic acidosis and even raised serum creatinine and blood urea nitrogen. In the late diuretic phase, the urine output is still above normal limits. The urine specific gravity is rising. Fluid and electrolyte balances and acid-base balances are within normal limits (Schrier, 2004) 3. More often than not, the only symptoms of acute renal failure is oliguria, which is defined as urine output of less than 400ml per day. If the urine output is less than 100 ml per day, it is known as anuria. other symptoms of acute renal failure include pedal edema, thirst and dry mouth, palpitations, dizziness, nausea and vomiting, loss of appetite, confusion, anxiousness, restlessness and sleepiness. The patient feels weak and this is known as asthenia. These are subjective symptoms. Objective features include severe dehydration, tachycardia, hypotension or even hypertension, seizures, irregular heart beat and pulmonary edema. The patient often has azotemia which may be defined as abnormal high levels of nitrogen-containing compounds, such as urea, creatinine, various body waste compounds, and other nitrogen-rich compounds in the blood. Rise in blood urea nitrogen is known as uremia. 4. The diet must have high carbohydrates, adequate fats, and low protein. This is because, high calories from carbohydrate and fat prevents breaking of protein for energy, which can be used for growth and repair. The potassium intake must be reduced. In oliguric renal failure, salt and fluid restriction must be adjusted to urine output and serum electrolyte levels. Potassium and phosphorus must be restricted in early oligiruc phase, but in polyuric phase, they can get depleted and hence must be replaced (Fry and farrington, 2006). 5. Medical management of acute renal failure includes renal replacement therapy in the form of dialysis. The dialysis can be continuous or intermittent. It can be peritoneal or hemodialysis. Indications for dialysis are uremia, severe azotemia, correction of severe acid-based imbalance refractory to regular management, hyperkalemia refractory to medical treatment and volume expansion that cannot be managed with diuretics. The patient must be advised complete rest and care must be organized to provide long term rest. This is because activity increases the rate of metabolism and also nitrogenous wastes. interventions must be provided to prevent infections and also complications of immotility. Metabolic acidosis and electrolyte disturbances must be corrected. Fluid balance must be maintained by adjusting input according to urine output. The patient must be observed for arrhythmias and cardiac arrest (Fry and Farrington, 2006). 6. Short term nursing goals in a patient with acute renal failure are (Bellomo ety al, 2004): 1. The patient will have normal fluid and electrolyte levels 2. The patient will experience no preventable complication like infection or cardiac arrest. Long term nursing goal includes that the patient will understand the means by which His/Her family members will implement health teaching after discharge. References Bellomo, R., Ronco, C., Kellum, J.A., Mehta, R.L., Palevsky, P. (2004). Acute renal failure - definition, outcome measures, animal models, fluid therapy and information technology needs: the Second International Consensus Conference of the Acute Dialysis Quality Initiative (ADQI) Group. Crit Care, 8(4), R204-12. Fry, A.C., and Farrington, K. (2006). Management of acute renal failure. Postgrad Med J., 82, 106-116. Schrier, R.W., Wang, W., Poole, B., Mitra, A. (2004). Acute renal failure: definitions, diagnosis, pathogenesis, and therapy. J Clin Invest., 114(1), 5-14. Workeneh, B.T., and Batuman, V. (2011). Acute renal failure. Medscape reference. Retrieved from http://emedicine.medscape.com/article/243492-overview Read More