urolithiasis word.docx

Over View of urolithiasis For patients with stones containing uric acid, struvite, or cystine, a thoroughphysical examination and metabolic workup are indicated because of associated disturbances contributing to the stone formation. Uric acid stones account for 72% of stones in men (Flagg & Join...

Over View of urolithiasis For patients with stones containing uric acid, struvite, or cystine, a thoroughphysical examination and metabolic workup are indicated because of associated disturbances contributing to the stone formation. Uric acid stones account for 72% of stones in men (Flagg & Joiner, 2017). These may be seen in patients with gout or myeloproliferative disorders. Seventy-two percent of stones diagnosed in women are struvite stones (Flagg & Joiner, 2017) which form in persistently alkaline, ammonia-rich urine caused by the presence of bacteria such as Proteus, Pseudomonas, Klebsiella, Staphylococcus, or Mycoplasma. Predisposing factors for struvite stones include neurogenic bladder, foreign bodies, and recurrent UTIs (Norris, 2019). Several conditions, as well as certain metabolic risk factors, predispose patients to stone formation. These include anatomic derangements such as polycystic kidney disease, horseshoe kidneys, chronic strictures, and medullary sponge disease. Urinary stone formation can occur in patients with inflammatory bowel disease and in those with an ileostomy or bowel resection because these patients absorb more oxalate. Medications known to cause stones in some patients include antacids, acetazolamide, vitamin D, laxatives, and high doses of aspirin (Comerford & Durkin, 2020). However, in many patients, no cause may be found. Signs and Symptoms Stones in the renal pelvis may be associated with an intense, deep ache in the costovertebral region. Hematuria is often present; pyuria may also be noted. Pain originating in the renal area radiates anteriorly and downward toward the bladder in the female and toward the testes in the male. If the pain suddenly becomes acute, with tenderness over the costovertebral area, and nausea and vomiting occur, the patient is having an episode of renal colic. Diarrhea and abdominal discomfort are due to renointestinal reflexes and the anatomic proximity of the kidneys to the stomach, pancreas, and large intestine. Stones lodged in the ureter (ureteral obstruction) cause acute, excruciating, colicky, wavelike pain that radiates down the thigh and to the genitalia. Often, the patient has a desire to void, but little urine is passed, and it usually contain blood because of the abrasive action of the stone. This group of symptoms is called ureteral colic. Colic is mediated by prostaglandin E, a substance that increases ureteral contractility and renal blood flow and that leads to increased intraureteral pressure and pain. In general, the patient is able to pass stones 0.5 cm in diameter (Norris, 2019). Stones larger than 1 cm in diameter usually must be removed or fragmented (broken up by lithotripsy) so that they can be removed or passed spontaneously. Stones lodged in the bladder usually produce symptoms of irritation and may be associated with UTI and hematuria. If the stone obstructs the bladder neck, urinary retention occurs. If infection is associated with a stone, the condition is far more serious, with the potential for urosepsis developing. Medical Management The goals of management are to eradicate the stone, determine the stone type, prevent nephron destruction, control infection, and relieve any obstruction that may be present. The immediate objective of treatment of renal or ureteral colic is to relieve the pain until its cause can be eliminated. Opioid analgesic agents are given to prevent shock and syncope that may result from the excruciating pain. Nonsteroidal anti-inflammatory drugs (NSAIDs) are effective in treating renal calculus pain because they provide specific pain relief. They also inhibit the synthesis of prostaglandin E, reducing swelling and facilitating passage of the stone. Generally, once the stone has passed, the pain is relieved. Unless the patient is vomiting or has heart failure or any other condition requiring fluid restriction, fluids are encouraged. This increases the hydrostatic pressure behind the stone, assisting it in its downward passage. A high, around-the clock fluid intake reduces the concentration of urinary crystalloids, dilutes the urine, and ensures a high urine output. Preventing Renal Calculi: Avoid protein intake to decrease urinary excretion of calcium and uric acid. Limit sodium intake to 3 to 4 g/day. Table salt and high-sodium foods should be reduced, because sodium competes with calcium for reabsorption in the kidneys. Be aware that low-calcium diets are not generally recommended, except for true absorptive hypercalciuria. Evidence shows that limiting calcium, especially in women, can lead to osteoporosis and does not prevent calculi. Avoid intake of oxalate-containing foods (e.g., spinach, Swiss chard, chocolate, peanuts, pecans). Drink fluids (ideally water) every 1 to 2 hours during the day and one glass of cranberry juice per day. Drink two glasses of water at bedtime and an additional glass at each nighttime awakening to prevent urine from becoming too concentrated during the night. Avoid activities leading to sudden increases in environmental temperatures that may cause excessive sweating and dehydration. Types of stones: Calcium Stones Historically, patients with calcium-based renal calculi were advised to restrict calcium in their diet. However, evidence has questioned this practice, except for patients with type 2 absorptive hypercalciuria (half of all patients with calcium stones), as stones in these patients are clearly the result of excess dietary calcium. Liberal fluid intake is encouraged. Medications such as ammonium chloride may be used, and if increased parathormone production (resulting in increased serum calcium levels in blood and urine) is a factor in the formation of stones, therapy with thiazide diuretics may be beneficial in levels (Cahill & Haras, 2017). Uric Acid Stones For uric acid stones, the patient is placed on a low-purine diet to reduce the excretion of uric acid in the urine. Foods high in purine (shellfish, anchovies, asparagus, mushrooms, and organ meats) are avoided, and other proteins may be limited. Allopurinol may be prescribed to reduce serum uric acid levels and urinary uric acid excretion, and to dissolve or reduce the size of existing stones (Cahill & Haras, 2017). Cystine Stones A low-protein diet may be prescribed, the urine is alkalinized with potassium alkali salts, and fluid intake is increased (Norris, 2019). Oxalate Stones A dilute urine is maintained through increasing fluid intake, and the intake of oxalate is limited. Many foods contain oxalate including spinach, Swiss chard, chocolate, peanuts, and pecans (Norris, 2019). Interventional procedures: Methods of treating renal calculi: During ureteroscopy, which is used for removing small stones located in the ureter close to the bladder, a ureteroscope is inserted into the ureter to visualize the stone. The stone is then fragmented or captured and removed. Extracorporeal shock water lithotripsy is used for most symptomatic, nonpassable upper urinary stones. Electromagnetically generated shock waves are focused over the area of the renal calculus. The high-energy dry shock waves pass through the skin and fragment the stone. Percutaneous nephrolithotomy is used to treat larger stones. A percutaneous tract is formed, and a nephroscope is inserted through it. Then, the stone is extracted or pulverized.