Question 28

Compare and contrast hepato-pulmonary syndrome, porto-pulmonary hypertension and hepatorenal syndrome. Use the following headings in your answer: definitions, pathophysiology, and specific treatment of these conditions. You may tabulate your answer.

[Click here to toggle visibility of the answers]

College answer

This question scored low, as many candidates could not define the different entities and therefore the subsequent aspects of the question were poorly answered.

Discussion

Below, for the pulmonary syndromes, the definitions are from the ERS task force statement of 2005, and the hepatorenal definition is from the 2012 ADQI consensus conference. Hepato-pulmonary pathophysiology and management options are from Benz et al (2020).

Hepato-pulmonary syndrome Porto-pulmonary hypertension Hepatorenal syndrome
Definitions
  • "An arterial oxygenation defect induced by intrapulmonary vascular dilatations associated with hepatic disease"
  • "Pulmonary arterial hypertension associated with portal hypertension, with or without hepatic disease" 
  • "Kidney injury resulting from renal vasoconstriction in the setting of systemic and splanchnic arterial vasodilatation in patients with advanced cirrhosis"
Pathophysiology
  • Increased vasodilator molecule release due to liver disease (NO, CO, endothelin-1)
  • Thus, impaired hypoxic pulmonary vasoconstriction and  enhanced angiogenesis,  producing V/Q mismatch and arteriovenous shunts
  • Decreased hepatic metabolism of vasoconstrictor substances
  • Hyperdynamic pulmonary circulation (thus, shear stress in the pulmonary vessels)
  • Increased inflammatory cytokines 
  • Thromboembolic phenomena originating in the portal circulation
  • Splanchnic arterial and venous vasodilation due to increase NO, CO, endothelin-1
  • Blood volume sequestration in  the splanchnic circulation
  • Compensatory renin-angiotensin-aldosterone overactivity and sympathetic overactivity
  • Thus,  renal arterial vasoconstriction
Specific treatment
  • Long term home oxygen
  • Cavoplasty
  • Angioembolisation of shunting AVMs
  • TIPS
  • Transplant
  • Oral and inhaled pulmonary vasodilators:
  • Prostacyclin
  • Phosphodiesterase inhibitors
  • Endothelin receptor antagonists
  • Noradrenaline
  • Albumin
  • Terlipressin
  • Octreotide
  • TIPS
  • Transplant

References

Vogel, Todd R., Rebecca Symons, and David R. Flum. "The incidence and factors associated with graft infection after aortic aneurysm repair." Journal of Vascular Surgery 47.2 (2008): 264-269.

Benz, Fabian, et al. "Pulmonary complications in patients with liver cirrhosis." Journal of translational internal medicine 8.3 (2020): 150-158.

Huang, Pei-Ming, et al. "The morphology of diaphragmatic defects in hepatic hydrothorax: thoracoscopic finding." The Journal of thoracic and cardiovascular surgery 130.1 (2005): 141-145.

Rodriguez-Roisin, R., et al. "Pulmonary–hepatic vascular disorders (PHD)." European Respiratory Journal 24.5 (2004): 861-880.

Krowka, Michael J. "Hepatopulmonary syndrome and portopulmonary hypertension: the pulmonary vascular enigmas of liver disease." Clinical Liver Disease 15.Suppl 1 (2020): S13.