Résumé
For the intensive care unit (ICU) physician, the diagnosis of pulmonary arterial hypertension (PAH) is difficult as it can easily be confounded with other forms of pulmonary hypertension (PH). The key issue is that PAH is a form of PH. On the opposite, PH does not automatically imply PAH. Pulmonary arterial hypertension must be differentiated from other causes of PH that are frequently seen in ICU. It was recently emphasized that pulmonary veno-occlusive disease (PVOD) must be differentiated from PH and PAH. The prognosis of PAH was consistently improved in the ten past years by introduction of selective pulmonary vasodilators and management by highly specialized medical teams. In ICU patients, PAH remains a severe disease with a high mortality rate. When PAH is suspected, a systematic diagnosis approach is of particular importance in order to rapidly eliminate left cardiac, thromboembolic and pulmonary causes of PH. Left cardiac disease is the most common cause of PH. Early recognition of PAH allows a rapid introduction of selective pulmonary vasodilators that can improve outcome. Idiopathic PAH is the most frequent cause but it can also be associated with scleroderma, HIV infection, anorexigen toxicity, thyroid disease, cirrhosis. Pulmonary vasodilators should be only a part of a general management including treatment of triggering factors, optimization of fluid balance, decrease of RV afterload by using pulmonary vasodilators while maintaining cardiac output and mean arterial pressure. The early contact of PH referral center or specialized physician is of particular importance.