Quiz 3

(Ref: Harrison 19th edition, page 1799)
Uremic pericarditis is characterized by chest pain. The failed kidneys fail to excrete H+.
The decrease in GFR explains the increase of renin leading to hypertension.
Hyperkalemia is always a feature of Oliguric phase of ARF.

(Ref: Harrison 20th edition, p 2977; Harrison 19th p 2513)
Four forms of Alport syndrome are:
1. Classic AS, which is inherited as an X-linked disorder with hematuria, sensori-neural deafness, and conical deformation of the anterior surface of the lens (lenticonus);
2. A subtype of the X-linked form associated with diffuse leiomyomatosis;
3. An autosomal recessive form; and
4. An autosomal dominant form. Both autosomal recessive and dominant forms can cause renal disease without deafness or lenticonus.
Molecular Defects
Most patients have mutations in four of the six genes for the chains of type IV collagen (COL4A3, COL4A4, COL4A5, and COL4A6).
Diagnosis: The diagnosis of classic AS is based on X-linked inheritance of hematuria, sensorineural deafness, and lenticonus. The lenticonus together with hematuria is pathognomonic of classic AS. The sensorineural deafness is primarily in the high-tone range. It can frequently be detected only by an audiogram and is usually not progressive. The hematuria usually progresses to nephritis and may cause renal failure in late adolescence in affected males and at older ages in some women. Renal transplantation is usually successful.

(Ref: Harrison 20th edition, p 2123; Harrison 19th edition, p 1822-23)
 The fistula, graft, or catheter through which blood is obtained for hemodialysis is often referred to as a dialysis access.
 A native fistula created by the anastomosis of an artery to a vein (e.g., the Brescia-Cimino fistula, in which the cephalic vein is anastomosed end-to-side to the radial artery) results in arterialization of the vein.
 This facilitates its subsequent use in the placement of large needles (typically 15 Gauge) to access the circulation.
 Fistulas have the highest long-term patency rate of all dialysis access options
 The most important complication of arteriovenous graft is thrombosis of the graft and graft failure, principally due to intimal hyperplasia at the anastomosis between the graft and recipient vein.
 Many patients undergo placement of an arteriovenous graft (i.e., the interposition of prosthetic material, usually polytetrafluoroethylene, between an artery and a vein) or a tunneled dialysis catheter

(Ref: Harrison 19th p 932)
 The two close possible diagnoses for the patient are PNEUMOCYSTIS or NOCARDIA.
 The first step diagnosis is examination of sputum or pus for crooked, branching, beaded, gram-positive filaments 1 microm wide and up to 50 micron long which is diagnostic of Nocardia.
 In contrast pneurnocystis on toluidine blue staining looks like crushed ping pong balls, and causes diffuse infiltrates on CXR.
 Pneumonia, the most common form of nocardial disease in the respiratory tract, is typically subacute; symptoms have usually been present for days or weeks at presentation.
 The onset is occasionally more acute in immunosuppressed patients.
 Cough is prominent and produces small amounts of thick, purulent sputum that is not malodorous. Fever, anorexia, weight loss, and malaise are common; dyspnea, pleuritic pain, and hemoptysis are less common.
 Roentgenographic patterns vary, but some are highly suggestive of nocardial pneumonia. Infiltrates vary in size and are typically dense. Single or multiple nodules are common, sometimes suggesting tumors or metastases. Infiltrates and nodules tend to cavitate. Empyema is present in one-quarter of cases.
 Sulfonamides are the drugs of choice. The combination of sulfamethoxazole (SMX) and trimethoprim (TMP) is probably equivalent to a sulfonamide alone.

(Ref: Harrison 20th edition, p 289)
Casts— These urinary sediments are formed by coagulation of albuminous material in the kidney tubules. Casts are cylindrical and vary in diameter. Casts in the urine always indicate some form of kidney disorder and should always be reported. If casts are present in large numbers, the urine is almost sure to be positive for albumin.
There are seven types of casts. They are as follows:
1. Hyaline casts are the most frequently occurring casts in urine. Hyaline casts can be seen in even the mildest renal disease. They are colorless, homogeneous, transparent, and usually have rounded ends.
2. Red cell casts indicate renal hematuria. Red cell casts may appear brown to almost colorless and are usually diagnostic of glomerular disease. White cell casts are present in renal infection and in noninfectious inflammation. The majority of white cells that appear in casts are hyper-segmented neutrophils.
3. Granular casts almost always indicate significant renal disease. However, granular casts may be present in the urine for a short time following strenuous exercise. Granular casts that contain fine granules may appear grey or pale yellow in color. Granular casts that contain larger coarse granules are darker. These casts often appear black because of the density of the granules.
4. Epithelial casts are rarely seen in urine because renal disease that primarily affects the tubules is infrequent. Epithelial casts may be arranged in parallel rows or haphazardly
5. Waxy casts result from the degeneration of granular casts. Waxy casts have been found in patients with severe chronic renal failure, malignant hypertension, and diabetic disease of the kidney. Waxy casts appear yellow, grey, or colorless. They frequently occur as short, broad casts, with blunt or broken ends, and often have cracked or serrated edges.
6. Fatty casts are seen when there is fatty degene-ration of the tubular epithelium, as in degene-rative tubular disease. Fatty casts also result from lupus and toxic renal poisoning. A typical fatty cast contains both large and small fat droplets. The small fat droplets are yellowish-brown in color.
7. Broad casts seen in C.K.D.

(Ref: Harrison 20th edition, p 2156; Harrison 19th edition, p 1855)
Renal papillary necrosis (RPN) is characterized by coagulative necrosis of the renal medullary pyramids and papillae brought on by several associated conditions and toxins that exhibit synergism toward the development of ischemia.
A useful mnemonic device for the conditions associated with renal papillary necrosis is POSTCARDS, which stands for the following:
 Pyelonephritis
 Obstruction of the urinary tract
 Sickle cell hemoglobinopathies, including sickle cell trait
 Tuberculosis
 Cirrhosis of the liver, chronic alboholism
 Analgesic abuse
 Renal transplant rejection, radiation
 Diabetes mellitus
 Systemic vasculitis