Measurement of effective pulmonary capillary pressure using the pressure profile after pulmonary artery occlusion

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Pulmonary veno-occlusive disease (PVOD) is currently classified as a subgroup of pulmonary arterial hypertension (PAH) and accounts for 5-10% of cases initially considered to be idiopathic PAH. PVOD has been described as idiopathic or complicating other conditions, including connective tissue diseases, HIV infection, bone marrow transplantation, sarcoidosis and pulmonary Langerhans cell granulomatosis. PVOD shares broadly similar clinical presentation, genetic background and haemodynamic characteristics with PAH. Compared to PAH, PVOD is characterised by a higher male/female ratio, higher tobacco exposure, lower arterial oxygen tension at rest, lower diffusing capacity of the lung for carbon monoxide, and lower oxygen saturation nadir during the 6-min walk test. High-resolution computed tomography (HRCT) of the chest can be suggestive of PVOD in the presence of centrilobular ground-glass opacities, septal lines and lymph node enlargement. Similarly, occult alveolar haemorrhage is associated with PVOD. A noninvasive diagnostic approach using HRCT of the chest, arterial blood gases, pulmonary function tests and bronchoalveolar lavage could be helpful for the detection of PVOD patients and in avoiding high-risk surgical lung biopsy for histological confirmation. PVOD is characterised by a poor prognosis and the possibility of developing severe pulmonary oedema with specific PAH therapy. Lung transplantation is the treatment of choice. Cautious use of specific PAH therapy can, however, be helpful in some patients.KEYWORDS: Alveolar haemorrhage, BMPR2, computed tomography, diffusing capacity of the lung for carbon monoxide, pulmonary arterial hypertension, pulmonary veno-occlusive disease P ulmonary arterial hypertension (PAH) is a severe condition characterised by elevated pulmonary artery pressure leading to right heart failure and death [1,2]. Pulmonary veno-occlusive disease (PVOD) is classified as a subgroup of PAH and accounts for 5-10% of histological forms of cases initially considered to be idiopathic PAH. Even though the first welldocumented case of PVOD was described .70 yrs ago, the characteristics and pathophysiology of this disease remain poorly understood [3,4]. While pulmonary vascular pathology of idiopathic or familial PAH is characterised by a major remodelling of small pre-capillary pulmonary arteries with typical plexiform and/or thrombotic lesions, PVOD preferentially affects the post-capillary venous pulmonary vessels [5,6]. Despite this anatomical histological difference, PVOD has a very similar clinical presentation to PAH but is characterised by a worse prognosis and the possibility that severe pulmonary oedema can develop with specific PAH therapy, justifying the importance of diagnosing this disease. A definitive diagnosis of PVOD requires histological analysis of a lung sample [7,8]; however, surgical lung biopsy is a high-risk procedure in these patients and the development of a less invasive diagnostic approach would be preferable [9][10][11]. The present manuscript will summa...

Section: Ppcwmentioning

confidence: 99%

Pulmonary veno-occlusive disease

Montani¹,

Price²,

Dorfmüller³

et al. 2008

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250

“…Clinically, capillary pressure is computed by analysing the PAP decay after single arterial occlusion by an intravascular balloon [53,84,85] (fig. 3).…”

Section: Pulmonary Resistance Partitioningmentioning

confidence: 99%

Haemodynamic evaluation of pulmonary hypertension

Chemla¹,

Castelain²,

Hervé³

et al. 2002

304

185

Haemodynamic evaluation of pulmonary hypertension. D. Chemla, V. Castelain, P. Hervé, Y. Lecarpentier, S. Brimioulle. #ERS Journals Ltd 2002. ABSTRACT: Pulmonary hypertension is characterised by the chronic elevation of pulmonary artery pressure (PAP) and pulmonary vascular resistance (PVR) leading to right ventricular enlargement and hypertrophy. Pulmonary hypertension may result from respiratory and cardiac diseases, the most severe forms occurring in thromboembolic and primary pulmonary hypertension.Pulmonary hypertension is most often defined as a mean PAP w25 mmHg at rest or w30 mmHg during exercise, the pressure being measured invasively with a pulmonary artery catheter. Doppler echocardiography allows serial, noninvasive follow-up of PAPs and right heart function. When the adaptive mechanisms of right ventricular dilatation and hypertrophy cannot compensate for the haemodynamic burden, right heart failure occurs and is associated with poor prognosis.The haemodynamic profile is the major determinant of prognosis. In both primary and secondary pulmonary hypertension, special attention must be paid to the assessment of pulmonary vascular resistance index (PVRI), right heart function and pulmonary vasodilatory reserve.Recent studies have stressed the prognostic values of exercise capacity (6-min walk test), right atrial pressure, stroke index and vasodilator challenge responses, as well as an interest in new imaging techniques and natriuretic peptide determinations. Overall, careful haemodynamic evaluation may optimise new diagnostic and therapeutic strategies in pulmonary hypertension.

“…The occlusion technique can be used in intact animals and patients for the partitioning of pulmonary vascular resistance (PVR) into an arterial segment (PVRa) and a capillary-venous segment, and for the determination of an effective pulmonary capillary pressure (Pc) [1,2]. The method identified a hydrostatic mechanism, with an important role accounting for early high-altitude pulmonary oedema [3].…”

mentioning

confidence: 99%

Single arterial occlusion to locate resistance in patients with pulmonary hypertension

Fesler

Pagnamenta²,

Vachiéry³

et al. 2003

The purpose of this study was to determine the site of increased resistance using the arterial occlusion technique in patients with severe pulmonary hypertension.Pulmonary vascular resistance was partitioned in arterial and venous components based on double exponential fitting analysis of the pulmonary artery pressure decay curve: after balloon occlusion in 36 patients with pulmonary arterial hypertension (PAH); at baseline and during the inhalation of 20 parts per million of nitric oxide (NO); in four patients with chronic thromboembolic pulmonary hypertension; and in two patients with pulmonary veno-occlusive disease.In the patients with PAH, at baseline, mean pulmonary artery pressure was 56¡2 mmHg (mean¡SE), with an arterial component of resistance of 63¡1%. Inhaled NO did not change the partition of resistance. The arterial component of resistance amounted on average to 42% and 77% in the patients with veno-occlusive disease and the patients with thromboembolic pulmonary hypertension, respectively. However, the partitioning of resistance did not discriminate between these three diagnostic categories.The occlusion technique may help to locate the predominant site of increased resistance in patients with severe pulmonary hypertension, but does not allow for a satisfactory differential diagnosis on an individual basis.