A. Van Meerhaeghe

Functional Evaluation in Stage I Pulmonary Sarcoidosis

A functional evaluation was performed in 9 non-smoking patients suffering from sarcoidosis characterized, on chest roentgenograms, by hilar adenopathies (stage I). Frequency dependence of compliance (5 cases) and decreased conductance of the upstream segment (3 cases) were the major findings. From this it is concluded that, even at stage I, small-airway impairment may be documented in some patients, suggesting the existence of peribronchiolar granulomatous infiltration.

Unilateral Pulmonary Edema Secondary to Left Heart Failure

A 56-year-old man with a failing aortic prothesis involving aortic insufficiency and with a dissecting aneurysm of the aortic cross, developed a unilateral pulmonary edema. Although radiological liter

Breathing Pattern and Neuromuscular Drive During CO2 Rebreathing in Normal Man and in Patients with COPD

In 11 normal subjects and in 10 patients with chronic obstructive pulmonary disease we evaluated breathing pattern and mouth occlusion pressure (PO.1), while breathing room air and during reinhalation of a hypercapnic hyperoxic gas mixture. In the breathing pattern we analyzed the time and volume components of the respiratory cycle: tidal volume (VT), inspiratory time (Ti), expiratory time (Te), total time of respiratory cycle (Ttot); mean inspiratory flow (VT/Ti) and Ti/Ttot ratios, respiratory frequency (RF) and instantaneous ventilation (VE). In the normal subjects, increase in VE during rebreathing mainly depended on an increase in both VT and VT/Ti without significant changes in Ti. During CO2 rebreathing the patients exhibited a lesser increase in VE compared to normals, due to a lesser increase in VT. However, expressing VT in percent of resting inspiratory capacity showed that VT attained at the end of rebreathing (VTmax) was similar to that noted in the normal subjects at the same minute of rebreathing. Furthermore, percent increase in VE, VT, VT/Ti and PO.1 between resting value and that at 56 mm Hg (delta %), were significant in both groups with a major increase in the normal subjects for VE and VT/Ti. In comparison, delta % decreases in both Te and Ttot were found to be significant only in the normal subjects. VT/Ti was related to VE in a similar way in the two groups. In contrast, in the normal subjects, Ti/Ttot did not increase with increasing VE. During rebreathing increase in PO.1 was found to be similar in the normal subjects and in patients. However, for a given neuromuscular drive VE and VT/Ti were greater in the normal subjects than in the patients. These data show that in the patients as a whole no significant changes in breath intervals occur during CO2 rebreathing. Furthermore, in patients, in spite of a similar increase in neuromuscular drive, the efficiency by which inspiratory muscle output (PO.1) is converted into VT/Ti was found to be reduced.

Lactate production and exercise-induced metabolic acidosis: guilty or not guilty?

To the Editors: In the excellent and very interesting chapter concerning clinical exercise testing published in the European Respiratory Monograph on lung function testing, Roca and Rabinovitch 1 wrote the following. “Increased lactate production is responsible for the fall in muscle pH, which in turn may play a role in determining exercise intolerance in these patients (COPD patients). Premature lactic acidosis during exercise in COPD patients has been associated with reduced oxidative enzyme concentrations …

Functional Evaluation of Tracheal Stenosis before and after Surgical Management

14 patients affected by tracheal stenosis resulting from assisted ventilation underwent a tracheal resection (n = 12) or dilatation (n = 2). Lung function tests were performed before and after surgical treatment. Prior to surgery, we observed a significant increase in airway resistance (Raw) in all subjects and a negative exponential relationship between Raw and FEV1/VC. Expiratory flows were also reduced with an increase in FEV1/PEFR ratios. After surgical correction of the stenosis, Raw normalized in 10 out of 14 subjects. The observed changes were more significant than for the other functional tests. After surgery, the patients follow-up with Raw allowed the diagnosis of recurrent stenosis in 4 subjects lacking significant clinical symptoms. We conclude that measurement of Raw helps the clinical diagnosis and the appreciation of the possible changes in airway permeability after the surgical procedure.

Flow limitation and dynamic hyperinflation

To the Editors: In the January issue of the European Respiratory Journal , in a very well-written paper, Calverley and Koulouris 1 comprehensively reviewed the concepts of expiratory flow limitation and dynamic hyperinflation, and assessed their potential importance in pulmonary disease. They underlined the fact that, in nonintrathoracic …