Syndrome of portal hypertension

Portal hypertension results from destruction and distortion of the hepatic vasculature leading to obstruction of blood flow and increasing backward pressure, resulting in hypertension in portal circulation. Normal pressure is 2-5 mmHg. Patients developing complications usually have portal pressure above 12 mmHg. On ultrasound maximum normal diameter of portal vein is 1 cm, it becomes dilated in portal hypertension.

Classification

Depending on the etiology and mechanism of developing there are the next forms of the portal hypertension syndrome:

I. Suprahepatic block:

- hepatic veins thrombosis;

- hepatic veins compression;

- vena cava inferior compression and/or thrombosis.

II. Intrahepatic block:

- chronic hepatitis;

- liver cirrhosis;

- tumor of the liver;

- metastatic liver damage.

III. Subhepatic block:

- congenital anomaly of vena porta;

- compression of a portal collector by a tumor;

- spasms.

 

The features of portal hypertension are as follows: splenomegaly, hypersplenism, collateral circulation and ascites.

Splenomegaly. Splenomegaly is a cardinal finding, and a diagnosis of portal hypertension is unlikely when splenomegaly can not be detected clinically or by ultrasonography. Clinical splenomegaly is present in 35-50% of cases.

Hypersplenism. When spleen becomes enlarged its function of removing cells from circulation also increases, this is called hypersplenism. Moderate thrombocytopenia frequently occurs (platelet count around l00x109/lit). Leukopenia occurs occasionally and anemia rarely.

By definition hypersplenism is characterized by: splenomegaly; cytopenia (thrombocytopenia, granulocytopenia or pancytopenia); normal bone marrow.

Collateral circulation. Increased portal vascular resistance leads to gradual reduction in the flow of portal blood to the liver and simultaneously to the development of collateral vessels, allowing the portal blood to bypass the liver and enter the systemic circulation directly. Collateral vessel formation is more prominent in the following areas:

• in the distal esophagus and proximal stomach (esophagogastric varices);

• in the distal rectum and anus(causing hemorrhoids);

• on the anterior abdominal wall which radiate prominently from the umbilicus forming "caput Medusae";

• renal, lumber, ovarian and testicular vessels (rare).

The most important collateral vessels are the esophagogastric varices as they can cause bleeding which is usually severe and acute. Bleeding from rectum and anus is rare.

Ascites. Accumulation of fluid in peritoneal cavity (ascites) in cirrhosis occurs, owing to two factors: portal hypertension and hepatic dysfunction. Portal hypertension causes transudation of fluid in peritoneal cavity from the portal circulation (due to increased hydrostatic pressure), while the hepatic dysfunction causes ascites by three mechanisms:

• salt and water retention occurs as a result of peripheral arterial vasodilatation and consequent reduction in effective blood volume. Nitric oxide is probably the vasodilator although prostaglandins and atrial natriuretic peptide may also be involved. The reduction in effective blood volume due to vasodilatation stimulates reninangiotensin system that promotes salt and water retention through stimulation of aldosterone. Failure of liver to metabolize aldosterone causes salt and water retention;

• liver is not able to synthesize sufficient proteins thus causing hypoalbuminemia, which results in decreased colloid osmotic pressure of the plasma resulting in leakage of fluid and development of edema and ascites;

• normally liver causes aldosterone metabolism, in case of hepatic dysfunction liver is unable to metabolize it, resulting in secondary hyperaldosteronism, and retention of sodium and water.

 

 

HEPATIC INSUFFICIENCY

Following are the features of hepatic insufficiency:

1. Jaundice: it is usually mild or absent. If occurs, it is mainly due to failure of bilirubin metabolism.

2. Circulatory changes: these changes result from increased peripheral circulation (hyperdynamic circulation) causing the following manifestations: palmar erythema: i t is mottled redness of the thenar and hypothenar eminences due to increased peripheral blood flow. Palmar erythema may also be present in normal old person, rheumatoid arthritis, pregnancy, thyrotoxicosis. Spider nevi: these are telangiectasia that result from arteriolar changes and comprise a central arteriole from which small vessels radiate. Spider nevi are confined to the area above the nipple and occurs on the face, necklace area, forearms and dorsum of hands.

3. Endocrine abnormalities:

• gynecomastia (because liver is unable to metabolize estogen, it may also develop as a side effect of diuretic spironolactone that is commonly used in cirrhosis;

• loss of libido;

• impotence and testicular atrophy in man;

• breast atrophy and amenorrhea.

4. Hemorrhagic tendency: it occurs in advanced liver failure and is due to underproduction of coagulation factors. The manifestations of hemorrhagic tendency may be:

• bruising, purpura;

• epistaxis;

• menorrhagia;

• GIT bleeding.

5. Skin changes:

• pigmentation occurs in cirrhosis (especially caused by hemochromatosis) and cirrhosis due to any reason as a result of cholestasis;

• clubbing of fingers and toes may also present.

6. Dupuytren's contracture associated with alcoholic cirrhosis and is very rare.

7. Hepatic encephalopathy. The cerebral disturbance or encephalopathy develops due to the following two factors:

• collateral venous circulation in cirrhosis bypasses the liver and allows nitrogenous substances from the gut to reach the systemic circulation through which they reach to the brain directly and produce cerebral disturbance;

• liver is responsible for detoxification of substances. When there is severe loss of liver function the un-detoxified substances such as ammonia reach to the brain, and produce cerebral dysfunction.

8. Renal failure (hepatorenal syndrome). It presents as low urine output, raised urea and creatinine, hyponatremia, low urinary sodium and hypotension. Kidneys are histologically normal and can work normally if transplanted to non-cirrhotic person. It occurs in advanced cirrhosis mostly with ascites is caused by decreased effective blood volume and hypotension as a result of vasodilatation due to release of nitric oxide from the liver. Details are given in the section of complications of ascites.

9. Hepatopulmonary syndrome. Incirrhosis pulmonary arteriovenous shunts also develop, leading to hypoxia and eventually central cyanosis, this is called hepatopulmonary syndrome.

 

Literature

1. Internal diseases an introductory course. - Vasilenko V., Grebenev A. - M.: Mir. Publishers, 1990. - 647 p

2. Propedeutics to internal medicine. Part 1.-Vinnytsya: NOVA KNYHA, 2006.- 424 p.

3. Propedeutics to internal medicine. Part 2.-Vinnytsya: NOVA KNYHA, 2007.- 264 p.

4. Introduction to the course of internal diseases. Book 1. Diagnosis: [Textbook/Zh.D. Semidotskaya, O.S. Bilchenko, et al.].-Kharkiv: KSMU, 2005. -312p.

5. Michael Swash Hutchison’s clinical methods / XIX edition. ELBS, 1989. -618p.

6. Mark H., Beers M.D., Robert Berkow The Merck Manual of diagnosis and therapy / XVII edition.- Published by Merk research laboratories, 1999.- 2833 p.

7. Harrison΄s principles off internal medicine / Fauci, Braunwald, Isselbacher and al.-XIV edition. - Vol. 1 and 2. - International edition, 1998.

 

 

Topic 13. The Main Symptoms and Syndromes in Renal Disease - Acute and Chronic Glomerulonephritis and Pyelonephritis.

 

Class lasts: 3 hours

Chronological class structure:

Control of initial standard of knowledges- 20 min.

Teacher′s demonstration of practical skills - 60 min.

Sudents′ independent work: - 30 min.

Control of ultimate standard of knowledges- 15 min.

Sum up of the class, homework- 10 min.

Questions for theoretical preparation: The definition and modern classification of glomerulonephritis and pyelonephritis. The main mechanisms of developing glomerulonephritis and pyelonephritis. Patient’s complaints in kidneys disorders and physical examination data in patients with glomerulonephritis and pyelonephritis. Edematous syndrome and syndrome of arterial hypertension in kidneys disease. The possibilities of instrumental diagnostics of kidneys pathology. Laboratory examination of urine, the analysis and the interpretation of the results of general clinical analysis of urine. The examination of urine by Nechiporenko, Ambjurrhe, Adiskakovsky, Zymnitskyj methods. Urinary, nephritic syndromes in renal diseases. The results of biochemical blood examination in kidneys pathology. The syndromes of renal insufficiency and renal colic.

 

GLOMERULONEPHRITIS

Glomerulonephritis is immune-inflammatory renal disease with obligatory glomerulus's injury and including to the pathological process of all renal structures.

In more cases glomerulonephritis is an independent nozological form but may be a result of systemic pathology or pathological states.

Classification

I. Acute glomerulonephritis

1. According to the variant:

- with urinary syndrome;

- with nephritic syndrome;

- with hypertension syndrome;

- mixed.

2. According to the duration:

- recidivated;

- lingering.

II. Subacute glomerulonephritis

III. Fast advance glomerulonephritis

IV. Chronic glomerulonephritis

1. According to the variant:

- with urinary syndrome;

- with nephritic syndrome;

- with hypertension syndrome;

- mixed;

- latent.

2. According to the stage:

- anhypertensive;

- hypertensive;

- renal failure:

• the period of anuria/oliguria;

• the period of diuresis reparation;

• the period of complete renal function reimbursement.

3. According to the duration:

- stable;

- progressive.

4. According to the phase:

- remission;

- aggravation.

Etiology

1. Influence of infection agent (primary streptococcus);

2. Endogenous antigens:

- systemic connective tissue diseases;

- systemic vasculitis;

- diabetes mellitus I or II type;

- viral hepatitis B or C type;

- the syndrome of arterial hypertension;

- later hystosis;

- other reasons.

3. Exogenous antigens:

- alcohol;

- toxic substances;

- poisons;

- bite of animals and insect;

- drugs.

4. Hereditary origin.

 

ACUTE GLOMERULONEPHRITIS

Acute glomerulonephritis is acute immuno-inflammatory renal disease with obligatory glomerulus's injury and afterward including to the pathological process of all renal structures.

Acute nephritis typically arises not during an infectious disease but only following a period of time, usually 2-3 weeks later. Attempts to isolate the streptococcus from the kidney tissue end in failure. Thus, the onset of acute nephritis usually coincides with the period when antibodies to streptococcus are produced.

Clinical features

The main complaint in patients with acute glomerulonephritis are weakness, thirst, pain in the back, dyspnea, palpitation, headache, nausea, vomiting, edema and lost of vision.

Objective examination: General patient's condition is from moderate grave to extremely grave. In general inspection detect "faces nephritica" - the face is edematous and often pale. Swelling usually appears first around the eyes in the morning and eyes may become slit like when edema is pronounced.

The color of the skin characterized by pathological pale, observed decreased turgor and elasticity of the skin, scars on the abdomen and hips due to the over stretching of the skin.

Edema in patients with nephritic syndrome (edema renalis) characterized by symmetrical localization, in initial stages arises on the face in the morning, has descending character and spreads on extremities, loin region with next fluid accumulation in cavities (hydrothorax, hydropericardium and anasarca). The skin over edema is glossy.

The apex beat is somewhat shifted to the left. In heart percussion observed displacement of the left border of the heart to the left. In heart auscultation detects tachycardia and gallops rhythm. Arterial pressure is increased.

Complications: acute renal failure, acute heart failure, encephalopathy, stroke, eclampsia, transitory vision impair.

Outcomes of disease: complete recovery, transformation to the chronic form.

Additional methods of examination

Clinical blood analysis: leukocytosis and increase of accelerated ESR.

Clinical urine analysis: in macroscopic study - urine is "meat wastes" color, cloudiness, without odor, olyguria, low specific gravity and moderate or significant proteinuria: in microscopic study observed large amount of altered erythrocytes (hematuria), cylinders (hyaline, erythrocytes and waxy casts) and leucocytes (non-constant).

Zimnitsky's test: izostenuria.

Nechiporenko's method: prevalence of erythrocytes under leucocytes; casts more 250 in ml.

Biochemistry of the blood: hypoproteinemia (hypoalbuminemia) and dysproteinemia.

Electrocardiography reveals signs of hypertrophy and overload of the left-ventricular myocardium. The amplitude of ECG waves decreases.

Renal biopsy: use for differential diagnosis and determination of the glomerulonephritis cause.