To detect whether pulmonary vascular responsiveness is a factor which can aggravate the pulmonary hypertension induced by irreversible pulmonary fibrosis, we examined the acute hemodynamic effects of low-flow oxygen and of nifedipine both at rest and during exercise in 8 patients with idiopathic pulmonary fibrosis (IPF). During exercise, the increments in pulmonary artery pressure, pulmonary vascular resistance (PVR), and right ventricular stroke work index relative to resting values were blunted by both treatments. During exercise, both systemic vascular resistance and PVR decreased more significantly after nifedipine than on oxygen (p < 0.001). At exercise, nifedipine administration induced a greater increment in oxygen delivery (CaO₂ × CI) than that produced by oxygen breathing (p < 0.01). Our results in patients with IPF seem to confirm that active vasoconstriction of pulmonary vessels may contribute to the pulmonary hypertension during exercise. The evaluation of reversibility of pulmonary hypertension by nifedipine in IPF deserves further long-term studies

In a single-blind placebo-controlled trial in 12 patients with advanced chronic obstructive pulmonary disease (COPD) we compared the effects of nebulized salbutamol (1 mg), clenbuterol (30 μg) and placebo (4 ml of normal saline) on spirometric indices (FVC, FEV₁), maximal expiratory flows (Vmax50 and Vmax25), the distance walked in 6 min (6MD), assessment of breathlessness by visual analogue scale (VAS), and estimates by the patients of perceived exertion (RPE). Both clenbuterol and salbutamol produced significant increases in FEV₁, FVC, Vmax50 and Vmax25. With both drugs, 6MD increased significantly (p < 0.01) and breathlessness decreased significantly without an appreciable increase in RPE after exercise despite the extra distance covered. The absolute improvements in FEV₁ and 6MD after clenbuterol were correlated (r = 0.763, p < 0.01), but these indices were not correlated after salbutamol (r = 0.121, p > 0.1). The lack of correlation between the changes in 6MD and FEV₁ after salbutamol might indicate that relief of airways obstruction is not the only explanation for the effects on distance walked, at least with salbutamol.

A 48-yr-old male presented with cyanosis and dyspnoea at minimal exertion. Over the last year he had been complaining of progressively increasing exertional dyspnoea, and during this time was hospitalized twice for pneumonia. His medical problems started 5 yrs ago when after an episode of haematemesis, cryptogenic hepatic cirrhosis with portal hypertension was diagnosed. He subsequently underwent successful sclerotherapy for oesophageal varices. He had a 30 pack-yr smoking history and worked as a technician of electronic devices. One of his sisters has been diagnosed and treated for idiopathic pulmonary fibrosis.On admission he was cyanotic and complained of nonproductive cough. His temperature was 37uC, pulse rate 98?min -1 , respiratory rate was 30?min -1 and his blood pressure 160/90 mmHg. Physical examination revealed finger clubbing and two spider nevi on his thorax but absence of ascitic fluid, pleural effusions, peripheral oedemas or lymph node enlargements. The liver was not palpable, but the spleen showed marked enlargement. The chest was clear to auscultation. A 2/6 systolic murmur was heard at the pulmonary artery focus.Blood analysis showed reduction of both white cells (3300610 6 ?L -1 ) and platelets (27000610 6 ?L -1 ). Blood chemistry was within normal range except for the international normalized ratio (INR) (1. 7) and serum bilirubin (total 63.3 M, indirect 41 M).Arterial blood gases analysis (while breathing room air) indicated marked hypoxaemia (arterial oyxgen tension (Pa,O 2 ): 4.3 kPa, arterial carbon dioxide tension (Pa,CO 2 ): 3.7 kPa, pH: 7.46, bicarbonate: 20.2 mM). Supplemental 100% oxygen was administered without significant response. Arterial blood gases while breathing 100% oxygen proved to worsen at upright position while improving at supine position (Pa,O 2 : 4.7 kPa, Pa,CO 2 : 3.8 kPa, pH: 7.46 versus Pa,O 2 : 7.2 kPa, Pa,CO 2 : 3.8 kPa, pH: 7.46). The observed "orthodeoxia" was compatible with the clinical improvement noted during supine position (platypnoea).The chest radiographs ( fig. 1a and 1b), computed tomography (CT) of the chest ( fig. 2) and the 99 Tc albumin macroaggregate body scan ( fig. 3), were as shown.

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