Portal hypertension is responsible for:
1. Gastrointestinal bleeding
2. Ascites
3. Portosystemic encephalopathy
4. Hepato-renal syndrome
5. Pulmonary disease:
a. Hepato-pulmonary syndrome
b. Porto-pulmonary hypertension
A. Hepatopulmonary syndrome
It is characterized by:
i. Portal hypertension (with or without cirrhosis)
ii. Hypoxaemia (A-a gradient > 15 mmHg on room air)
iii. Evidence of pulmonary vascular dilatation
Diagnosis: Contrast enhanced echocardiography demonstrates delayed visualization of microbubbles (more than 3 cardiac cycles) into the left heart of injected agitated saline bubbles intravenously. This suggests intrapulmonary shunt, whereas immediate visualization would suggest intracardiac shunting.
Treatment: Oxygen therapy, exclusion of other causes of hypoxaemia (shunt) and liver transplant
B. Portopulmonary hypertension
It is characterized by:
i. Portal hypertension
ii. PCWP < 15 mmHg
iii. Pulmonary hypertension (mPAP > 25 mmHg at rest)
iv. Pulmonary vascular resistance > 120 dynes per m-5 (3 Woods units)
Diagnosis: Right heart catheterization with measurement of PAP is the 'gold standard for diagnosis.
Treatment is a liver transplant (LT). In appropriately selected subjects, LT can effectively treat all the complacations of endstage CLD. LT can be determined by calculation of the model for end-stage liver disease (MELD) score. It is contraindicated in severe pulmonary hypertension (mPAP > 50 mmHg) but can be considered in those who respond to treatment with oral or IV vasodilator therapy.
Reference: Manual of Intensive Care by Irwin and Rippe.
Questions: Forty year old man with history of hepatitis C presents with dyspnoea. On examination he is jaundiced, with spider naevi and ascites. Chest X-Ray and spirometry are normal. Pulse oximetry is performed: Standing 88% and Supine 97%. (From data interpretation in critical care medicine)
1. What is the likely diagnosis?
Answer: Hepatopulmonary syndrome in end-stage Hep C cirrhosis.
2. What is the postulated pathophysiological mechanisms?
Answer: Intrapulmonary vasodilation with right to left shunting. The process affects mainly the bases. Changes in posture that increase basal pulmonary blood flow (upright position) worsen gas exchange.
Orthodeoxia is hypoxaemia accentuated in the upright position.
Platypnoea is increased dyspnoea in upright position, improved by assuming the recumbent position. Causes are: a. Intracardiac shunts (intra-atrial shunt) with or without lung disease and b. Pulmonary vascular shunts (pulmonary artery-pulmonary vein communications) either anatomical or parenchymal.
3. What further investigation is indicated?
Answer: see above
4. Is liver transplantation likely to help?
Answer: Yes, over 80% of patients with hepatopulmonary syndrome have resolution or marked improvement in intrapulmonary vasodilatation with LT. This contrasts with portopulmonary hypertension which is considered a contraindication (see comment above).
1. Gastrointestinal bleeding
2. Ascites
3. Portosystemic encephalopathy
4. Hepato-renal syndrome
5. Pulmonary disease:
a. Hepato-pulmonary syndrome
b. Porto-pulmonary hypertension
A. Hepatopulmonary syndrome
It is characterized by:
i. Portal hypertension (with or without cirrhosis)
ii. Hypoxaemia (A-a gradient > 15 mmHg on room air)
iii. Evidence of pulmonary vascular dilatation
Diagnosis: Contrast enhanced echocardiography demonstrates delayed visualization of microbubbles (more than 3 cardiac cycles) into the left heart of injected agitated saline bubbles intravenously. This suggests intrapulmonary shunt, whereas immediate visualization would suggest intracardiac shunting.
Treatment: Oxygen therapy, exclusion of other causes of hypoxaemia (shunt) and liver transplant
B. Portopulmonary hypertension
It is characterized by:
i. Portal hypertension
ii. PCWP < 15 mmHg
iii. Pulmonary hypertension (mPAP > 25 mmHg at rest)
iv. Pulmonary vascular resistance > 120 dynes per m-5 (3 Woods units)
Diagnosis: Right heart catheterization with measurement of PAP is the 'gold standard for diagnosis.
Treatment is a liver transplant (LT). In appropriately selected subjects, LT can effectively treat all the complacations of endstage CLD. LT can be determined by calculation of the model for end-stage liver disease (MELD) score. It is contraindicated in severe pulmonary hypertension (mPAP > 50 mmHg) but can be considered in those who respond to treatment with oral or IV vasodilator therapy.
Reference: Manual of Intensive Care by Irwin and Rippe.
Questions: Forty year old man with history of hepatitis C presents with dyspnoea. On examination he is jaundiced, with spider naevi and ascites. Chest X-Ray and spirometry are normal. Pulse oximetry is performed: Standing 88% and Supine 97%. (From data interpretation in critical care medicine)
1. What is the likely diagnosis?
Answer: Hepatopulmonary syndrome in end-stage Hep C cirrhosis.
2. What is the postulated pathophysiological mechanisms?
Answer: Intrapulmonary vasodilation with right to left shunting. The process affects mainly the bases. Changes in posture that increase basal pulmonary blood flow (upright position) worsen gas exchange.
Orthodeoxia is hypoxaemia accentuated in the upright position.
Platypnoea is increased dyspnoea in upright position, improved by assuming the recumbent position. Causes are: a. Intracardiac shunts (intra-atrial shunt) with or without lung disease and b. Pulmonary vascular shunts (pulmonary artery-pulmonary vein communications) either anatomical or parenchymal.
3. What further investigation is indicated?
Answer: see above
4. Is liver transplantation likely to help?
Answer: Yes, over 80% of patients with hepatopulmonary syndrome have resolution or marked improvement in intrapulmonary vasodilatation with LT. This contrasts with portopulmonary hypertension which is considered a contraindication (see comment above).
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