Critically unwell PH patients have high mortality
Factors predicting poor outcome include relative hypoxaemia (low SpO2/FiO2 ratio), low cardiac output (base deficit, lactate, renal failure), and venous congestion (hepatic / renal failure)
Requirement for invasive ventilation confers high risk, often not appropriate
On the other hand, RRT may be of benefit in selected patients
Discussion with a regional centre is advised