6.3 RENAL DISORDERS - INTERSTITIAL, RENAL FAILURE AND LITHIASIS Flashcards
What diseases are classified under interstitial disorders
Urinary Tract Infection (UTI),
Acute Pyelonephritis,
Chronic Pyelonephritis, and
Acute Interstitial Nephritis (AIN).
What interstitial disorder primarily involves infection of the bladder or upper urinary tract?
Urinary Tract Infection (UTI)
What are common symptoms of cystitis in a UTI?
Urinary frequency, burning sensation, and mild proteinuria or hematuria.
What is absent in the urinalysis that differentiates cystitis from pyelonephritis?
Pathological casts
What interstitial disorder involves infection of both the tubules and interstitium of the upper urinary tract?
Acute Pyelonephritis
What are the key symptoms of acute pyelonephritis?
Rapid onset of urinary frequency, burning during urination, and lower back pain.
What enhances the ascending movement of bacteria from the bladder in acute pyelonephritis?
Obstructions like renal calculi, pregnancy, or vesicoureteral reflux (VUR).
What urinalysis finding is the primary diagnostic value for acute pyelonephritis?
White blood cell (WBC) casts.
What additional urinalysis sediment may indicate tubule infection in acute pyelonephritis?
Bacterial casts.
What interstitial disorder is often caused by congenital urinary structural defects?
Chronic Pyelonephritis
What are the most common causes of chronic pyelonephritis?
Reflux nephropathy,
structural abnormalities, and
bladder reflux.
What urinalysis findings indicate advanced stages of chronic pyelonephritis?
Granular, waxy, and broad casts,
with increased proteinuria and hematuria
What decreases as chronic pyelonephritis progresses?
Renal concentration ability.
What interstitial disorder is marked by inflammation of the renal interstitium and tubules?
Acute Interstitial Nephritis (AIN)
What are common symptoms of acute interstitial nephritis (AIN)?
Rapid onset of oliguria, edema, fever, and skin rash
What primarily causes acute interstitial nephritis (AIN)?
Allergic reactions to medications.
Which medications are commonly associated with AIN?
Penicillin, methicillin, NSAIDs, sulfonamides, thiazide diuretics, and cephalosporins
What specific urinalysis findings are characteristic of AIN?
Eosinophils, eosinophil casts, hematuria, and WBC casts without bacteria.
What diagnostic test may confirm the diagnosis of AIN?
Differential leukocyte staining showing increased eosinophils.
What are the two main forms of renal failure?
Acute Renal Failure (ARF) and Chronic Renal Failure (CRF).
What distinguishes acute renal failure from chronic renal failure?
ARF has a sudden loss of renal function, often reversible, while CRF is a gradual and often irreversible process.
What are the primary causes of acute renal failure (ARF)?
Prerenal (decreased blood flow to kidneys), renal (acute glomerular and tubular disease), and postrenal (obstructions such as renal calculi or tumors).
What general symptoms are associated with ARF?
Decreased glomerular filtration rate, oliguria, edema, and azotemia
What urinalysis findings may indicate prerenal ARF?
Presence of renal tubular epithelial (RTE) cells and casts.
What urinalysis findings may indicate renal ARF?
RBCs suggest glomerular injury; WBC casts with or without bacteria indicate interstitial infection or inflammation.
What urinalysis findings may indicate postrenal ARF?
Normal or abnormal urothelial cells, possibly associated with malignancy.
What characterizes the progression to chronic renal failure (CRF)?
Marked decrease in GFR (<25 mL/min), azotemia,
electrolyte imbalance,
isosthenuric urine,
proteinuria,
renal glycosuria, and
broad casts.
What casts are often referred to as “renal failure casts”?
Broad casts.
What is another name for renal lithiasis?
Kidney stones
What symptoms are associated with small kidney stones?
Severe pain radiating from the lower back to the legs and possible microscopic hematuria
What are common constituents of renal calculi?
Calcium oxalate,
calcium phosphate,
magnesium ammonium phosphate (struvite), uric acid, and
cystine.
What condition is associated with magnesium ammonium phosphate (struvite) stones?
Urinary infections involving urea-splitting bacteria, with a urine pH >7.0
What dietary and metabolic factors may contribute to uric acid stones?
High purine intake and uromodulin-associated kidney disease, with a urine pH <7.0.
What hereditary condition is linked to cystine stones?
Disorders of cystine metabolism.
What urinalysis finding is common in patients with renal calculi?
Microscopic hematuria caused by tissue irritation from moving calculi.
What are the key management strategies for preventing renal calculi formation?
Maintaining urine pH incompatible with crystallization, adequate hydration, and dietary restrictions.
What are the key laboratory indicators for Chronic Renal Failure (CRF)?
Decreased glomerular filtration rate (GFR)
Increased serum BUN (blood urea nitrogen)
Increased serum creatinine levels (azotemia)
Electrolyte imbalances (e.g., hyperkalemia, hyperphosphatemia, hypocalcemia)
Proteinuria (often with increased albumin excretion)
Renal glycosuria (glucose in urine despite normal blood glucose levels)
Broad, granular, and waxy casts, often referred to as a telescoped urine sediment
How does renal concentrating ability change in chronic renal failure?
There is a loss of renal concentrating ability, leading to isosthenuria, where the urine specific gravity becomes fixed at around 1.010, indicating the kidney’s inability to concentrate or dilute urine appropriately
What are some clinical manifestations of chronic renal failure (CRF) apart from laboratory findings?
Fatigue and weakness
Edema, often in the lower extremities
Nausea and vomiting
Loss of appetite (anorexia)
Hypertension
Uremic symptoms (uremic frost, pruritus, mental confusion, and seizures in advanced stages)
refers to the accumulation of nitrogenous waste products, primarily urea and creatinine, in the blood due to decreased kidney function, often seen in both acute and chronic renal failure.
Azotemia
What risk factors contribute to the formation of renal calculi (kidney stones)?
Dehydration and low fluid intake
Diet high in calcium, oxalate, and purine-rich foods (e.g., red meat, shellfish)
Obesity
Hypercalciuria (excess calcium in urine)
Hyperoxaluria (excess oxalate in urine)
Hyperuricosuria (excess uric acid in urine)
Certain metabolic disorders, such as hyperparathyroidism or cystinuria
Urinary tract infections (UTIs) with urea-splitting organisms
How do pH levels influence the formation of renal calculi?
Alkaline urine (pH > 7.0) favors the formation of calcium phosphate and magnesium ammonium phosphate (struvite) stones.
Acidic urine (pH < 7.0) favors the formation of uric acid and cystine stones.
occurs when the concentration of certain substances in the urine exceeds their solubility, leading to the formation of crystals that can aggregate into stones.
Urine supersaturation
Factors influencing supersaturation include
low urine volume, high urinary excretion of stone-forming substances, and the pH of urine.
are large, branching stones that typically form in the renal pelvis and extend into the calyces. They often result from chronic urinary tract infections and can cause significant obstruction, leading to renal damage and possible loss of kidney function if not treated.
Staghorn calculi
What are the potential complications associated with untreated renal calculi?
hydronephrosis
Recurrent urinary tract infections (UTIs)
Renal damage and loss of kidney function
Painful renal colic
swelling of the kidney due to urine buildup
hydronephrosis
What is the typical management for patients passing renal calculi?
Pain management with analgesics
Hydration to promote stone passage
Medications such as alpha-blockers (e.g., tamsulosin)
Lithotripsy (shockwave treatment)
Surgical removal for very large stones
How is the composition of renal calculi analyzed in the laboratory?
Chemical analysis
X-ray crystallography
Determines the chemical composition of the stone, often revealing calcium oxalate, calcium phosphate, uric acid, magnesium ammonium phosphate, or cystine.
Chemical analysis
Provides detailed structural analysis of the stones, helping to identify less common components.
X-ray crystallography
refers to the presence of crystals in the urine
Crystalluria
