PORTAL HYPERTENSION – Etiology, Pathophysiology, Signs and Symptoms, Diagnostic Evaluation and Management
Portal hypertension refers to abnormally high pressure in the hepatic portal vein. It is defined as a portal pressure of 12 mm Hg or more (compared with the normal 5-10 mm Hg)
ETIOLOGY
- Prehepatic causes (congential atresia or stenosis, portal vein thrombosis, splenic vein thrombosis, extrinsic compression tumors)
- Hepatic cause (chronic hepatitis, myeloproliferative diseases, idiopathic portal hypertension, granulomata, nodular (nodular regenerative hyperplasia, partial nodular transformation), toxins, fibropolycystic disease (including congenital hepatic fibrosis)
- Posthepatic – blockage of hepatic veins or venules (Budd-Chiari syndrome (hepatic vein obstruction), constrictive pericarditis, right heart failure, sclerosing hyaline necrosis)
PATHOPHYSIOLOGY
Increased vascular resistance in the portal venous system-from various mechanical causes —- activation of stellate cells and myofibroblasts, contributing to the abnormal blood flow patterns —- increased blood flow in the portal veins-from splanchnic arteriolar —- vasodilatation, caused by an excessive release of endogenous vasodilators —- the raised portal pressure opens up venous collaterals, connecting the portal and systemic venous systems. These occur in various sites, gastroesophageal junction —- producing varices which are superficial and easily bleed —- portal hypertension —- decreased intravascular volume —- ascites
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Alcohol abuse and Malnutrition – Laennec’s cirrhosis
Infection and drugs – Post necrotic cirrhosis
Biliary obstruction – Biliary cirrhosis
These three conditions leads to —– Destruction of hepatocytes —- Fibrosis/Scarring —- Obstruction of blood flow, increased pressure in the venous and sinusoidal channels, fatty infiltration fibrosis/scarring —- Portal Hypertension
SIGNS AND SYMPTOMS
- Dilated veins in the anterior abdominal wall
- Splenomegaly
- Ascites
- Jaundice
- Spider veins
- Palmar erythema
- Confusion
- Enlarged or small liver
- Gynecomastia
- Testicular atrophy
DIAGNOSTIC EVALUATION
- Blood tests
- Abdominal ultrasound – for liver and spleen size, ascites, portal blood flow and thrombosis of the portal or splenic veins
- Doppler ultrasound – can show direction of flow in blood vessels
- CT scan, especially spiral CT, may show portal vasculature MRI scan – gives similar information to CT
- Endoscopy
- Portal hypertension measurement: portal pressure is indirectly measured in clinical practice by the hepatic venous pressure gradient (HVPG)
- Liver biopsy
- Vascular imaging: the site of the portal venous block can be demonstrated by examining the venous phase of a celiac or superior mesenteric arteriogram, by splenic portography following injection of dye into the splenic pulp, or by retrograde portography via a hepatic vein
- Hepatic venography is helpful when hepatic vein block or idiopathic portal hypertension is suspected
COMPLICATIONS
- Bleeding from esophageal or gastric
- Ascites
- Spontaneous bacterial peritonitis
- Hepatorenal syndrome
- Hepatic hydrothorax
- Pulmonary complications
- Liver failure
- Hepatic encephalopathy
- Cirrhotic cardiomyopathy
MANAGEMENT
Pharmacological Management
- Beta blockers: nonselective beta blockers reduce portal pressure in many patients
- Nitrates: added to beta blocker therapy, they contribute to reducing portal pressure and may reduce rates of variceal rebleeding
- Vasoactive drugs: terlipressin and octreotide are used to assist the control of acute variceal bleeding
Surgical Management
- Transjugular intrahepatic portosystemic shunt (TIPS): it is a radiological procedure, connecting the portal and hepatic veins using a stent. The purpose of TIPS is to decompress the portal venous system, to prevent rebleeding from varices or to reduce the formation of ascites
- Surgical portosystemic shunts
- Devascularizationn procedures: these include gastroesophageal devascularization, splenectomy and esophageal transaction
NURSING MANAGEMENT
Nursing Diagnosis
- Risk for infection related to ascites
- Activity intolerance related to weakness
- Risk for imbalanced fluid volume related to vomiting and edema
Interventions
- Administer medications, which may include diuretics
- Assist the health care provider with paracentesis, which removes the fluid (e.g. ascites) from the peritoneal cavity
- Measure and record abdominal girth and body weight daily, assess for abdominal fluid wave
- Promote measures to prevent or reduce edema
- Encourage the client to elevate the lower extremities and wear support to prevent lower-extremity edema
- Administer salt-poor albumin, which temporarily elevates the serum albumin level. This increases serum osmotic pressure, helping to reduce edema by causing ascetic fluid to be drawn back into the blood stream and eliminated by the kidneys
- Measure dietary intake by caloric count
- Weigh as indicated. Compare changes in fluid status, recent weight history, and skinfold measurement
- Encourage patient to eat, explain reasons for the types of diet. Include patient in meal planning to consider his or her preferences in food choices
- Encourage patient to eat all meals including supplementary feeding unless contraindicated
- Give small, frequent meals
- Provide salt substitutes, if allowed and avoid those containing ammonium
- Restrict intake of caffeine, gas-producing or spicy and excessively hot or cold foods
- Suggest soft foods, avoiding roughage, if indicated
- Encourage frequent mouth care, especially before meals
- Promote undisturbed rest periods, especially before meals
- Measure intake and output chart, weigh daily and note gain of more than 0.5 kg/day
- Assess respiratory status, noting increased respiratory rate and dyspnea
- Auscultate lungs, noting diminished breath sounds and developing adventitious sounds
- Monitor for cardiac dysrhythmias. Auscultate heart sounds, noting development of S3/S4 gallop rhythm
- Assess degree of peripheral edema
- Measure abdominal girth encourage bedrest when ascites is present
- Provide frequent mouth care, occasional ice chips (if NPO)
- Monitor serum albumin and electrolytes (particularly potassium and sodium)
- Monitor serial chest X-rays
- Restrict sodium and fluids as indicated
- Administer salt-free albumin, plasma expanders, positive inotropic drugs and arterial vasodilators
- Administer diuretics: spironolactone, furosemide, etc
