Medical Musing of the Week: Hepatopulmonary Syndrome

Overview

  • Hypoxia in setting of patient with kown liver disease and likely Pulmonary HTN
  • Less common complication of Cirrhosis/ESLD (est 4-47%)
  • Triad:
    • Increased Arterial to alverolar O2 gradient
    • Pulmonary Vascular Vasodilation
    • Underlying Liver Disease

Pathophysiology

  • Type 1: Increasesd circulating vasodilators such as nitrous oxide, leading to vasodilation in capillary and precapillary beds of the lungs
  • Type 2: AVM’s
  • Overall patients have an increased in total number of dilated vessels

image

Clinical Manifestations

  • Platynea: Dyspnea when sitting up and relieved lying down
  • Orthodeoxia: Decreased arterial O2 tension (>4mmHg) or arterial oxyhemoglobin desaturation of >5% from lying to upright
  • Hypoxemia (not specific)
  • Liver disease present
  • Digital Clubbing
image
Digital Clubbing.

Diagnosis

  • O2 Therapy will temporarily improve patients with type 1 but not type 2 (because it is an AVM)
  • Contrast enhanced echocardiogram is preferred study for diagnosis–> contrast injected if normal will only opacify right chambers of the heart because they will be filtered by pulmonary capillary bed.
  • Intracardiac shunt is demonstrated if contrast is visualized in L heart within 3 beats.Β  Intrapulmonary shut (as in hepatopulmonary syndrome) will occur slightly later after 3 beats and usually within 3-6 beats
  • TEE is a better study but also more invasive and is contraindicated in patients with varices
image
God love radiologists. I can’t appreciate anything besides the right lung looks substantially different than the left. God speed to those who can πŸ™‚

Treatment

  • Type 1 patients can be offered improvement of symptoms with oxygen.
  • Type 2 patients will require embolizationΒ  as O2 therapy does not offer any relief in the setting ov AVM’s
  • Definitive treatment for both is Liver transplant.
Resources:
UpToDate & Principles of Critical Care (Sonali Sakaria & Ram M. Subramanian)

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