Acute Kidney Failure Health Article

Peritoneal dialysis

Peritoneal dialysis may be used if the patient in AKF is stable and not in immediate crisis. In peritoneal dialysis (PD), the lining of the patient's abdomen, the peritoneum, acts as a blood filter. A flexible tube-like instrument (catheter) is surgically inserted into the patient's abdomen. During treatment, the catheter is used to fill the abdominal cavity with dialysate. Waste products and excess fluids move from the patient's bloodstream into the dialysate solution. After a certain time period, the waste-filled dialysate is drained from the abdomen, and replaced with clean dialysate. There are three types of peritoneal dialysis, which vary according to treatment time and administration method.

Peritoneal dialysis is often the best treatment option for infants and children. Their small size can make vein access difficult to maintain. It is not recommended for patients with abdominal adhesions or other abdominal defects (like a hernia) that might reduce the efficiency of the treatment. It is also not recommended for patients who suffer frequent bouts of an inflammation of the small pouches in the intestinal tract (diverticulitis).

Prognosis

Because many of the illnesses and underlying conditions that often trigger AKF are critical, the prognosis for these patients many times is not good. Studies have estimated overall death rates for AKF at 42-88%. Many people, however, die because of the primary disease that has caused the kidney failure. These figures may also be misleading because patients who experience kidney failure as a result of less serious illnesses (like kidney stones or dehydration) have an excellent chance of complete recovery. Early recognition and prompt, appropriate treatment are key to patient recovery.

Survival statistics also depend on the type of AKF the patient has, age at time of onset, and general health. If the patient has prerenal AKF, there is a good recovery prognosis, but the mortality rate is higher among those who fail to respond to diuretics and vasodilator therapy. Since 1980, age has become a risk factor that increased mortality in patients with acute tubular necrosis (ATN), an intrinsic form of AKF.

Up to 10% of patients who experience AKF will suffer irreversible kidney damage. They will eventually go on to develop chronic kidney failure or end-stage renal

disease. These patients will require long-term dialysis or kidney transplantation to replace their lost renal functioning.

Health care team roles

The patient who suffers from AKF will come in contact with a number of different health care professionals during both the diagnosis and treatment phase of the illness. Patients will require (according to the type and severity of their condition) laboratory work, diagnostic radiology services, pharmaceutical and nutritional interventions, dialysis (in some cases), nursing care, and disease management by a nephrologist.

The medical history, taken by a physician in the emergency room, the patient's family doctor, a fellow nurse practitioner, physician's assistant (PA), or a nephrologist is the most essential tool in determining the cause and type of AKF. The admitting physician or nephrologist will conduct a thorough physical, looking at the following areas for specific clues.

Skin. Checking the patient for areas of small, purple or red spots (petechiae), hemorrhage beneath the skin (purpura), and bluish discoloration of a fairly large area of the skin (ecchymosis) can lead to a diagnosis of an inflammatory or vascular cause for the AKF.

Eyes. Certain conditions in the eyes can point to a diagnosis of interstitial nephritis (inflammation between the cells and tissues of the kidney) or necrotizing vasculitis (inflammed blood vessels).

Cardiovascular and volume status. Evaluating the condition of the heart and the rest of the circulatory system plus volume status (fluid balance) is the most important part of diagnosing and managing AKF. Nurses and nurses' aides will measure and chart daily intake and output (measuring how much fluid the patient takes in and how much he or she excretes in a 24-hour period of time). This is one of the best ways to get a good estimate of volume status. The pulse rate and blood pressure will be taken by the physician, nurses, and nurses' aides often in both the upright (standing or sitting on the side of the bed with legs dangling down) and supine (lying down) positions. The physician will also check the pulse in the neck, examine the heart and lungs, and check for edema (fluid buildup) in the arms and legs. Different combinations of the results of these assessments point to different causes for and types of AKF.

Abdomen. The physician will feel for signs of urinary tract obstruction by palpating (pressing) on the bladder and the upper corners of the abdomen that may reveal an obstruction in the ureter (tube between the kidney and the bladder) somewhere. If the entire abdomen is unusually swollen and filled with fluid (ascites), the AKF may be the result of liver failure.

Arms and legs (extremities). The physican and nursing staff will check the patients arms and legs for edema at the time of diagnosis and throughout treatment. Edema in the arms and legs is a sign of a decrease in oxygenated blood (ischemia), muscle tenderness from rhabdomyolysis (disease of the skeletal muscle), or arthritis. The presence and degree of edema is helpful in pinpointing the cause of AKF and in measuring the patient's progress with treatment.

Nervous system. The physician will assess the patient's degree of mental clarity and nerve responses, as abnormalities in these areas of the nervous system are often common symptoms of AKF. The nursing staff also monitors the patient's mental status during the course of treatment.

Laboratory personnel will draw blood and collect urine samples to help diagnose AKF and later, to evaluate treatment. Increases in BUN (blood urea nitrogen) and creatinine (substance formed from the metabolism of creatine) are indicators of AKF.

The urinalysis is the most important test run in the early stage of AKF evaluation. Significant color changes point to an intrinsic cause for AKF. Urine dipstick tests that prove positive for proteinuria (too much protein) and blood are helpful in diagnosing many causes of AKF. The different types of sediment readings from spun urine samples can further help to distinguish the cause and type of AKF. Urine electrolytes indicate how well the tubules (part of the kidney's nephron) are working.

Nurses and nurses' aides will keep track of fluids the patient takes in (intake) and eliminates (output) to help determine the type of AKF the patient is in and to help the physician manage the patient's course of treatment. Fluid management is critical in the patient with AKF, regardless of the cause.

Patients in AKF may undergo further evaluation in the Radiology Department to determine the cause of their disease and to plan an appropriate plan of treatment. They may undergo an ultrasound examination, doppler scan, nuclear scan, MRI, renal angiography, or a renal biopsy. The ultrasound, doppler scan, and MRI are the least invasive of the procedures. Contrast material is injected for the angiogram and the renal biopsy requires taking tissue samples from the kidney itself. These procedures are performed by trained and licensed radiologic technologists and radiologists.

Nutrition is crucial to the effective management of the patient in AKF. The dietician will work closely with the patient, physician, nursing staff, and pharmacist to ensure proper electrolyte balance, whether the patient eats regular foods or is nourished by total parenteral nutrition (TPN, nutrients mixed and fed through a tube).

Some patients will require kidney dialysis that will be performed by nurses and technicians from the renal or urology department.

Since many different medications are eliminated through the kidneys, the physician works closely with the pharmacist to modify dosing and minimize the use of medications that are toxic to the kidneys.