Bulletin européen de physiopathologie respiratoire
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Bull Eur Physiopathol Respir · Jan 1986
Comparative StudyBronchial responsiveness in asthmatic children aged 3 to 8 years measured by forced pseudo-random noise oscillometry.
With the forced pseudo-random noise oscillation technique (FOT), resistance (Rrs) and reactance (Xrs) of the respiratory system can be measured simultaneously over a frequency spectrum of 2-26 Hz. As only passive cooperation of the child is needed, FOT is suitable for lung function measurements from the age of 2 1/2 years. Hence bronchial responsiveness can be measured in children who are not yet able to perform spirometry or flow-volume curves. ⋯ Threshold dose or provocative dose to histamine and methacholine showed a close correlation in asthmatic children aged 3.6 to 7.8 years. The 24 hour interval within-subject reproducibility of threshold dose and provocative dose to histamine in asthmatic children aged 3.9 to 8.5 years proved to be good. Bronchial responsiveness to histamine or methacholine measured by FOT was not influenced by baseline lung function or by bronchial smooth muscle tone.
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Bull Eur Physiopathol Respir · Jul 1985
Positive expiratory pressure (PEP-mask) physiotherapy improves ventilation and reduces volume of trapped gas in cystic fibrosis.
To investigate the lung function during positive expiratory pressure (PEP) physiotherapy in cystic fibrosis, the resistance tube of the PEP-mask was inserted into the expiratory outlet of our lung function equipment. This enabled us to measure a variety of lung function variables, while the lung function equipment functioned as a PEP-mask. ⋯ It is concluded that in cystic fibrosis PEP-mask physiotherapy evens the intrapulmonary distribution of the ventilation and opens up regions, that are otherwise closed off. The results support the clinical observation that PEP-mask physiotherapy increases the transcutaneous tension of oxygen and the expectoration of sputum.
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Bull Eur Physiopathol Respir · May 1985
ReviewVentilatory support for pulmonary failure of the head trauma patient.
Severe head trauma patients frequently develop pulmonary failure. The aetiology of this respiratory distress may be central (neurogenic pulmonary oedema, delayed neurogenic pulmonary dysfunction, abnormal respiratory patterns) or peripheral, due to chest trauma, multiple trauma or lung infection. Hypoxia and hypercarbia alter cerebral haemodynamics, increase intracranial pressure and cause secondary deterioration of neurological function. ⋯ The effects of PEEP on cerebral perfusion pressure and on intracranial pressure depend on the interaction of pulmonary compliance, cerebral pressure/volume relationship and cerebral vascular autoregulation. High levels of PEEP may be deleterious in patients with altered cerebral autoregulation. High frequency ventilation theoretically has less influence on intrathoracic pressures and on cerebral haemodynamics but has not been shown superior in the respiratory support of severe head trauma patients.
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Bull Eur Physiopathol Respir · May 1985
Comparative StudyConstant mean airway pressure with different patterns of positive pressure breathing during the adult respiratory distress syndrome.
Twenty-one ARDS patients were divided into two groups of severity according to FIO2 and PEEP required to maintain an adequate gas exchange. The 10 most severe patients (group A) underwent continuous positive pressure ventilation (CPPV) (I/E 3:1) with the mean airway pressure maintained at 21 +/- 6.2 cmH2O. The PEEP values were 12.6 +/- 4.3 cmH2O during CPPV and 6.5 +/- 3.7 cmH2O during IRV (p less than 0.01). ⋯ In five patients of each group, the SF6 shunt was measured as representative of true shunt. The results showed that gas exchange, including true shunt, and haemodynamics did not change between CPPV and IRV and between CPPV and CPAP tests. Taken with previous work on mean airway pressure, our results further support the concept that the main determinant of oxygenation and haemodynamics is the mean airway pressure, irrespective of the PEEP level and of the mode of ventilation.
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Bull Eur Physiopathol Respir · May 1985
Complement activation in the adult respiratory distress syndrome following cardiopulmonary bypass.
We investigated complement fractions in patients after extracorporeal circulation for coronary bypass operations or cardiac valve replacement, and in two cases developing an adult respiratory distress syndrome (ARDS) after this type of intervention. The patients presenting an ARDS had significantly increased levels of C3d (p less than 0.001), the small molecular breakdown product of C3, associated with decreased levels of total classic haemolytic activity (p less than 0.05) and of the complement component C1q (p less than 0.001) when compared to a group of 10 patients who had uneventful evolution after bypass. However, all patients undergoing cardiopulmonary bypass had significantly increased levels of C3d (p less than 0.005 or less) associated with significant decrease of various complement components within 24 h after bypass, when compared to a control group of 5 patients investigated after aorto-iliac bypass graft surgery. We conclude that significant complement activation can persist in patients 24 h after bypass and--at higher levels--be a pathogenic and biological marker of ARDS after extracorporeal circulation.