Renal Disorders

Renal Disorders


Acute kidney injury, formerly known as acute renal failure, is the sudden interruption of renal function. Acute kidney injury can be caused by obstruction, poor circulation, or underlying kidney disease. It may be prerenal, intrarenal, or postrenal in origin; it usually passes through three distinct phases: oliguric, diuretic, and recovery.


Prerenal Kidney Injury

  • Arrhythmias, cardiac tamponade, cardiogenic shock, heart failure, and myocardial infarction

  • Prolonged hypotension

  • Burns, trauma, sepsis, and tumor

  • Dehydration and hypovolemic shock

  • Diuretic overuse and antihypertensive drugs

  • Hemorrhage, arterial embolism, arterial or venous thrombosis, and vasculitis

  • Disseminated intravascular coagulation

  • Eclampsia and malignant hypertension Intrarenal Kidney Injury

  • Poorly treated prerenal failure

  • Nephrotoxins

  • Obstetric complications

  • Crush injuries

  • Myopathy

  • Transfusion reaction

  • Acute glomerulonephritis, acute interstitial nephritis, acute pyelonephritis, bilateral renal vein thrombosis, malignant nephrosclerosis, and papillary necrosis

  • Polyarteritis nodosa

  • Renal myeloma

  • Sickle cell disease

  • Systemic lupus erythematosus

  • Vasculitis

Postrenal Kidney Injury

  • Bladder, ureteral, or urethral obstruction


Acute tubular necrosis, also known as acute tubulointerstitial nephritis, accounts for about 75% of all cases of acute renal failure and is the most common cause of acute renal failure in hospitalized patients. Acute tubular necrosis injures the tubular segment of the nephron, causing renal failure and uremic syndrome. Mortality ranges from 40% to 70%, depending on complications from underlying diseases. Nonoliguric forms of acute tubular necrosis have a better prognosis.


Acute tubular necrosis results from ischemic or nephrotoxic injury, most commonly in debilitated patients, such as the critically ill or those who have undergone extensive surgery.

Ischemic Injury

  • Sepsis

  • Severe hypotension

  • Dehydration

  • Heart failure

  • Surgery

  • Anesthetics

  • Transfusion reactions

  • Burns

Nephrotoxic Injury

  • Certain medications such as aminoglycosides

  • Contrast media


Cancer of the bladder is the most common cancer of the urinary tract.

Workers in certain industries (rubber workers, weavers and leather finishers, aniline dye workers, hairdressers, petroleum workers, and spray painters) are at high risk for bladder cancer. The period between exposure to the carcinogen and development of symptoms is about 18 years.


Primary cause unknown

Predisposing Factors

  • Smoking is most common causative factor

  • Transitional cell tumors — certain environmental carcinogens, including 2-naphthylamine, benzidine, tobacco, and nitrates

  • Squamous cell carcinoma of the bladder:

    • chronic bladder irritation or infection; for example, from kidney stones, indwelling urinary catheters, and cystitis from cyclophosphamide

    • schistosomiasis.


Cystitis and urethritis, the two forms of lower urinary tract infection (UTI), are nearly 10 times more common in women than in men and affect about 10% to 20% of all women at least once. Lower UTI is also a prevalent bacterial disease in children, most commonly in girls. Men are less vulnerable because their urethras are longer and their prostatic fluid serves as an antibacterial shield. In both men and women, infection usually ascends from the urethra to the bladder. UTIs generally respond readily to treatment, but recurrence and resistant bacterial flare-up during therapy are possible.


Ascending infection by a single, gram-negative, enteric species of bacteria, the most common being Escherichia (commonly Escherichia coli). Other less common organisms include Klebsiella, Proteus, Enterobacter, Pseudomonas, Staphylococcus saprophyticus, or Serratia.

In Women

  • Predisposition to infection by bacteria from vagina, perineum, rectum, or a sexual partner, a possible result of a short urethra

In Men and Children

  • Commonly related to anatomic or physiologic abnormalities


  • In 99% of patients, reinfection by the same organism or a new pathogen

  • Persistent infection — usually from renal calculi, chronic bacterial prostatitis, or a structural anomaly that harbors bacteria

Sep 22, 2018 | Posted by in ANATOMY | Comments Off on Renal Disorders
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