A paradoxical effect of bronchodilators.

Lactic acidosis previously has been reported during treatment of asthma with beta-2 agonists. However, this metabolic disturbance never had any clinical consequence. We report a case of a patient with asthma in whom beta-2 agonist administration increased dyspnea by metabolic acidosis due to a sharp increase in lactate levels (hyperlactatemia) and led to inappropriate intensification of bronchodilator therapy.

[Treatments for pulmonary arterial hypertension]. / Traitement de l'hypertension artérielle pulmonaire.

PURPOSE: Pulmonary arterial hypertension (PAH) is characterized by vasoconstriction, in situ thrombosis and vascular remodeling of small pulmonary arteries inducing a fixed pulmonary arterial obstruction and persistent elevation of pulmonary arterial resistance. Conventional treatment is based on simple measures (exercise limitation) and non-specific drugs (warfarine, diuretics, oxygen). CURRENT KNOWLEDGE AND KEY POINTS: Pure vasodilators like calcium channel antagonists have little or no effect on the vast majority of patients, presumably because fixed pulmonary arteriopathy predominate over vasoconstriction. Intravenous prostacyclin (epoprostenol) and endothelin receptor antagonists have vasodilator and antiproliferative properties. Epoprostenol therapy has resulted in significant improvements in prognosis of this disease and this drug remains the first-line treatment of the most severe patients. Bosentan is an interesting first-line treatment for NYHA functional class III patients. Availability of novel specific drugs (endothelin receptor type A antagonists, prostacyclin analogues, type 5 phosphodiesterase inhibitors) open new perspectives in treatment of PAH. The long-term benefit of these drugs remains to be evaluated and their respective place in treatment of these patients is still uncertain. We here present the different therapeutic alternatives available in the PAH and propose an algorithm for treatment of these patients. FUTURE PROSPECTS AND PROJECTS: The evolution of therapy from vasodilators to antiproliferative agents reflects the advancement in our understanding of the mechanisms mediating pulmonary arterial hypertension.

[Pulmonary hypertension complicating systemic diseases other than connective tissue diseases]. / Les hypertensions artérielles pulmonaires compliquant des maladies systémiques en dehors des connectivites.

A COMPLICATION OF CERTAIN SYSTEMIC DISEASES: Pulmonary hypertension (PH) can complicate the progression of certain systemic diseases such as sarcoidosis, histiocytosis X and some vasculites. The mechanisms at the origin of PH are varied and always require rigorous analysis in order to optimise treatment. DEPENDING ON THE DISEASE: PH associated with sarcoidosis is essentially related to specific lung parenchymal fibrosis and is poorly responder to corticosteroids. Other mechanisms may be more rarely incriminated (compressive andenopathies, mediastinal fibrosis, florid sarcoidosis concomitant to a pulmonary occlusive vascular disease...). During histiocytosis X, the ventilatory limitation of these patients does not always correlate with the severity of the respiratory failure, suggesting the existence of a pulmonary vascular disease progressing independently of the pulmonary parenchymal lesions. The pulmonary artery damage during Takayasu's arteritis and other auto-immune pulmonary arteritis may lead to potentially life-threatening complications, notably through stenosis and/or obstruction of the pulmonary arteries. Pulmonary hypertension is exceptional during Wegener's disease or periateritis nodosa. CONCLUSION: PH can complicate the progression of certain systemic diseases. The physiopathological mechanisms responsible are unclear (specific parenchymal fibrosis, isolated vascular involvement...). Globally, available treatments are disappointing.

[Pulmonary hypertension and obesity]. / Hypertension artérielle pulmonaire et obésité

Obesity is a morbid condition with hemodynamic consequences affecting the systemic and pulmonary circulations leading to a risk of pulmonary hypertension. Data in the literature do not argue in favor of a direct relationship between pulmonary hypertension and obesity. These two conditions appear to be two distinct entities, the different co-morbidities observed in obesity favoring pulmonary hypertension. Certain co-morbidities, for instance use of anorexic agents, exhibit a clear relationship with pulmonary hypertension. There is also a possible relationship with left ventricular failure, hypoxemia, and other respiratory disorders (including obstructive sleep apnea), hypothyroidism, and thomboembolism.

Mycobacterium heckeshornense: an emerging pathogen responsible for a recurrent lung infection.

Mycobacterium heckeshornense was responsible for a severe, recurrent and chronic pulmonary infection in an immunocompetent 65-year-old woman. The pathogen, initially identified as Mycobacterium xenopi and considered as a contaminant, led to a delayed adapted antimicrobial treatment. Although M. heckeshornense is phenotypically closely related to M. xenopi, its pathogenicity is noticeably higher. Accurate molecular diagnosis methods and treatment guidelines are needed to improve the management of patients infected by this uncommon pathogen.

Splenectomy and chronic thromboembolic pulmonary hypertension.

BACKGROUND: An increased prevalence of splenectomy has been reported in patients with idiopathic pulmonary arterial hypertension. Examination of small pulmonary arteries from these subjects has revealed multiple thrombotic lesions, suggesting that thrombosis may contribute to this condition. Based on these findings, we hypothesised that splenectomy could be a risk factor for chronic thromboembolic pulmonary hypertension (CTEPH), a condition defined by the absence of thrombus resolution after acute pulmonary embolism that causes sustained obstruction of the pulmonary arteries and subsequent pulmonary hypertension. METHODS: The medical history, clinical characteristics, thrombotic risk factors and haemodynamics of 257 patients referred for CTEPH between 1989 and 1999 were reviewed. In a case-control study the prevalence of splenectomy in patients with CTEPH was compared with that of patients evaluated during the same period for idiopathic pulmonary hypertension (n=276) or for lung transplantation in other chronic pulmonary conditions (n=180). RESULTS: In patients with CTEPH, 8.6% (95% CI 5.2 to 12.0) had a history of splenectomy compared with 2.5% (95% CI 0.7 to 4.4) and 0.56% (95% CI 0 to 1.6) in cases of idiopathic pulmonary arterial hypertension and other chronic pulmonary conditions, respectively (p<0.01). CONCLUSION: Splenectomy may be a risk factor for chronic thromboembolic pulmonary hypertension.