1 edema

Editor's Notes

• #4: Ref: Robbin’s Path Figure 4-1  Factors affecting fluid balance across capillary walls. Capillary hydrostatic and osmotic forces are normally balanced so that there is no net loss or gain of fluid across the capillary bed. However, increased hydrostatic pressure or diminished plasma osmotic pressure leads to a net accumulation of extravascular fluid (edema). As the interstitial fluid pressure increases, tissue lymphatics remove much of the excess volume, eventually returning it to the circulation via the thoracic duct. If the ability of the lymphatics to drain tissue is exceeded, persistent tissue edema results.
• #9: Body Fluid Compartments: The total body fluid is distributed mainly between two compartments: the extracellular fluid and the intracellular fluid (Figure 25–1). The extracellular fluid is divided into the interstitial fluid and the blood plasma. There is another small compartment of fluid that is referred to as transcellular fluid. This compartment includes fluid in the synovial, peritoneal, pericardial, and intraocular spaces, as well as the cerebrospinal fluid; it is usually considered to be a specialized type of extracellular fluid, although in some cases, its composition may differ markedly from that of the plasma or interstitial fluid. All the transcellular fluids together constitute about 1 to 2 liters.
• #12: 1-Fluid intake: intake via the gut or parenterally may exceed the ability of the kidneys to eliminate water. 2-Integrity of the kidneys: Damage to the renal parenchyma may diminish the elimination of fluid. 3-Hormone activity: Aldosterone (increases resorption of sodium by distal tubule which in turn results in retention of water). ADH (increases reabsorption of water by distal and collecting tubules).
• #15: Subcutaneous edema may have different distributions depending on the cause. It can be diffuse, or it may be relatively more conspicuous at the sites of highest hydrostatic pressures. In the latter case, the edema distribution is typically influenced by gravity and is termed dependent. Edema of the dependent parts of the body (e.g., the legs when standing, the sacrum when recumbent) is a prominent feature of congestive heart failure, particularly of the right ventricle. Edema as a result of renal dysfunction or nephrotic syndrome is generally more severe than cardiac edema and affects all parts of the body equally. It may, however, initially manifest itself in tissues with a loose connective tissue matrix, such as the eyelids; thus, periorbital edema is a characteristic finding in severe renal disease. Finger pressure over substantially edematous subcutaneous tissue displaces the interstitial fluid and leaves a finger-shaped depression, so-called pitting edema. Pulmonary edema is a common clinical problem ( Chapter 15 ) most typically seen in the setting of left ventricular failure but also occurring in renal failure, acute respiratory distress syndrome ( Chapter 15 ), pulmonary infections, and hypersensitivity reactions. The lungs are two to three times their normal weight, and sectioning reveals frothy, blood-tinged fluid representing a mixture of air, edema fluid, and extravasated red blood cells. Edema of the brain may be localized (e.g., owing to abscess or neoplasm) or may be generalized, as in encephalitis, hypertensive crises, or obstruction to the brain's venous outflow. Trauma may result in local or generalized edema depending on the nature and extent of the injury. With generalized edema, the brain is grossly swollen, with narrowed sulci and distended gyri, showing signs of flattening against the unyielding skull.
• #16: Clinical Correlation. Effects of edema may range from merely annoying to fatal. Subcutaneous tissue edema in cardiac or renal failure is important primarily because it signals underlying disease; however, when significant, it can also impair wound healing or the clearance of infection. Pulmonary edema can cause death by interfering with normal ventilatory function. Not only does fluid collect in the alveolar septa around capillaries and impede oxygen diffusion, but edema fluid in the alveolar spaces also creates a favorable environment for bacterial infection. Brain edema is serious and can be rapidly fatal; if severe, brain substance can herniate (extrude) through, for example, the foramen magnum, or the brain stem vascular supply can be compressed. Either condition can injure the medullary centers and cause death.
• #17: The term edema signifies increased fluid in the interstitial tissue spaces. In addition, depending on the site, fluid collections in the different body cavities are variously designated hydrothorax, hydropericardium, and hydroperitoneum (the last is more commonly called ascites). Anasarca is a severe and generalized edema with profound subcutaneous tissue swelling.
• #19: Taken from Guyton & Hall – Human Physiology and Mechanisms of Disease
• #25: The Budd-Chiari Syndrome: syndrome hepatic venous obstruction. Note the grossly dilated veins in the abdominal wall, in which the flow of blood was upwards. The patient had continued to work as a builder's labourer without symptoms, until he was admitted with coincidental appendicitis. The cause of his hepatic venous obstruction was unclear.
• #32: varicosities-1 Varicose veins around the foot and medial leg varicosites-2 Varicose veins around the knee and thigh.
• #36: Fig-1: A large amount of the thrombi extracted with a Fogarty catheter. Fig-2: The photograph on the left shows a massive thrombus in the femoral vein of the leg. This large thrombus dislodged, formed a thromboembolus, which traveled to the lung and resulted in pulmonary embolus. The photograph on the right shows the thromboembolus after removal from the pulmonary vessels. A large thromboembolus that completely occludes the entire pulmonary artery by lodging at the bifurcation of the pulmonary trunk is often fatal, as it was in this case. DVT = deep vein thrombosis; PE = pulmonary embolism. Sources: Cotran RS, Kumar V, Robbins SL. Robbins Pathologic Basis of Disease. 5th ed. Philadelphia, Pa: WB Saunders; 1994:111; Yonkman FF, ed.
• #37: Superior vena cacval syndrome: Superior vena cava obstruction causing dilated veins and plethora of the upper trunk and neck in a patient with bronchial carcinoma. Patients with SVC obstruction are occasionally referred to dermatologists with suspected contact allergy (eyelid swelling) or angioedema (facial or hand swelling).
• #39: A pleural effusion occurs when fluid collects in the potential space between the parietal pleura on the lung and the visceral pleura on the chest wall. In this case, the fluid is red (serosanguinous), while the presence of clear fluid would be called a serous effusion--a transudate with few or no cells. However, an exudate would include cells and protein and have a cloudy appearance.
• #40: -The right pleural cavity is filled with a cloudy yellowish-tan fluid, characteristic for a chylothorax, which is uncommon. In this case, malignant lymphoma involving the lymphatics of the chest and abdomen led to the collection of chylous fluid. The right lung is markedly atelectatic.
• #41: The chest radiograph here demonstrates a large pleural effusion nearly filling the left chest cavity. This fluid collection occurred postoperatively following a left pneumonectomy.
• #55: Hydrops: is excessive accumulation of watery fluid in existing organ cavities such as gall bladder. Special forms of hydrops include hydrocephalus and ascitis.
• #56: Sclerosis: persistent lymphedema stimulates proliferation of stromal fibroblasts which form collagen. This leads to fibortic hardening of tissue that was formerly soft and edematous.
• #61: peau d'orange (orange peel): Such a finely pitted appearance results from an accentuation of depressions in the skin at the site of hair follicles.
• #63: There are prominent linear white markings outlining lung lobules as seen on the external surface of this lung. The metastases are following the lymphatics between the lobules. The cut surface of this lung reveals linear interstitial markings and nodules in a case of lymphangitic spread of metastatic carcinoma, one of the less common pattern of metastasis. Th chest CT scan above in lung window and below in bone window both demonstrate a diffuse reticular and nodular pattern of involvement by metastatic carcinoma spreading into the lymphatic channels of the lung. There is also a large malignant pleural effusion on the left.
• #64: A nest of metastatic infiltrating ductal carcinoma from breast is seen in a dilated lymphatic channel in the lung. Carcinomas often metastasize via lymphatics. Prostatic adenocarcinoma is famous for metastasizing to the lungs in a "lymphangitic" pattern in which streaks of tumor appear between lung lobules and beneath the pleura in lymphatic spaces.
• #72: The right pleural cavity is filled with a cloudy yellowish-tan fluid, characteristic for a chylothorax, which is uncommon. In this case, malignant lymphoma involving the lymphatics of the chest and abdomen led to the collection of chylous fluid. The right lung is markedly atelectatic.
• #92: coldurticaria1: ice cube test for cold urticaria
• #101: The smooth, glistening pleural surface of a lung is shown here. This patient had marked pulmonary edema, which increased the fluid in the lymphatics that run between lung lobules. Thus, the lung lobules are outlined in white.
• #103: At high magnification, the alveoli in this lung are filled with a smooth to slightly floccular pink material characteristic for pulmonary edema. Note also that the capillaries in the alveolar walls are congested with many red blood cells. Congestion and edema of the lungs is common in patients with heart failure and in areas of inflammation of the lung.
• #104: Pulmonary congestion with dilated capillaries and leakage of blood into alveolar spaces leads to an increase in hemosiderin-laden macrophages, as seen here. Brown granules of hemosiderin from break down of RBC's appear in the macrophage cytoplasm. These macrophages are sometimes called "heart failure cells" because of their association with pulmonary congestion with congestive heart failure.
• #107: Ref: Robbin’s Path Figure 4-2  Sequence of events leading to systemic edema due to primary heart failure, primary renal failure, or reduced plasma osmotic pressure (as in malnutrition, diminished hepatic protein synthesis, or loss of protein owing to the nephrotic syndrome). ADH, antidiuretic hormone; GFR, glomerular filtration rate.
• #110: Distended Jugular Veins: This patient with severe mitral stenosis is sitting upright. Note the distention of the jugular veins almost to the mandible, reflecting elevated pressures in right heart pressure.
• #112: OP=oncotic pressure.
• #117: pretibialmyxedema2: Pretibial myxedema demonstrating the peau d’orange appearance which is typical of diffuse cutaneous mucin deposition. pretibialmyxedema1: Pretibial myxedema in thyrotoxicosis. Deposition of mucin in this condition is often variable in degree, leading to a cobblestoned appearance of the lower legs. Toes are also often affected.