The European respiratory journal : official journal of the European Society for Clinical Respiratory Physiology
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Randomized Controlled Trial Comparative Study Clinical Trial
Comparison of drug delivery from conventional versus "Venturi" nebulizers.
Attempts to improve drug delivery from conventional jet nebulizers have included the use of storage systems to reduce drug wastage during exhalation. Venturi nebulizers enhance drug delivery during inhalation, reducing treatment times and drug wastage. This study investigated the effect of age on inhaled dose from a conventional jet nebulizer (Acorn) used both with and without a storage chamber (Mizer), compared to two Venturi nebulizers (Ventstream and Pari LC). ⋯ Aerosol particle size using the Ventstream was lower than the other nebulizer systems. Drug output from both Venturi nebulizers was more efficient than from the jet nebulizer, used with and without the storage chamber, during inhalation by children with cystic fibrosis. The inhaled dose did not change with the patient's age or size using both types of nebulizer.
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Survival after lung transplantation is less than 50% after 5 yrs and is limited by infection and obliterative bronchiolitis. There is, therefore, a need for new immunosuppressive regimens if we are to attempt to improve long-term survival. ⋯ Recent novel approaches to the vexing problem of resistant lung rejection and obliterative bronchiolitis, such as the use of aerosolized cyclosporine, methotrexate, total lymphoid irradiation and phototherapy, are discussed. Finally an immunosuppressive regimen, using these new drugs in lung transplantation is suggested.
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The objective of this study was to compare the breathing pattern of patients who failed to wean from mechanical ventilation to the pattern during acute respiratory failure. We hypothesized that a similar breathing pattern occurs under both conditions. Breathing pattern, mouth occlusion pressure (P[0.1]) and maximum inspiratory pressure (P[I,max]) were measured in 15 patients during acute respiratory failure, within 24 h of the institution of mechanical ventilation, and in 49 patients during recovery, when they were ready for discontinuation from mechanical ventilation. ⋯ The P(I,max) of patients who failed to wean was similar to that of patients who weaned successfully. We conclude that patients who failed to wean had a breathing pattern similar to that during acute respiratory failure, despite a reduced mechanical load on the respiratory muscles and a relatively adequate inspiratory muscle strength. This suggests that strategies that enhance respiratory muscle endurance may facilitate weaning.
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In order to assess the relative contribution of the lung and the chest wall to the derangements of respiratory mechanics in chronic obstructive pulmonary disease (COPD) patients with acute ventilatory failure (AVF), we studied eight COPD patients undergoing controlled mechanical ventilation for AVF and nine normal subjects anaesthetized for surgery as a control group. With the use of the interrupter technique together with the oesophageal balloon technique we measured: static lung and chest wall elastances (E[st,L] and E[st,w], respectively), maximum (R[L,max]), minimum (R[L,min]) and additional (deltaR[L]) lung resistances, additional chest wall resistance (deltaRw) and, in the COPD group, total intrinsic positive end-expiratory pressure (PEEPtot). ⋯ We found that, in the COPD group: 1) both E(st,w) and deltaRw were higher than in the normal group; 2) R(L,max) was markedly increased due to an increase of both R(L,min) and deltaRL; 3) even low levels of PEEP increased PEEPtot; 4) PEEP did not reduce elastance or total resistance of either the lung or the chest wall. We conclude that chest wall mechanics are abnormal in chronic obstructive pulmonary disease patients with acute ventilatory failure undergoing controlled mechanical ventilation and that positive end-expiratory pressure does not seem to be effective in reducing either elastance or resistance of the lung or chest wall.
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Randomized Controlled Trial Clinical Trial
Lack of effect of high doses of inhaled morphine on exercise endurance in chronic obstructive pulmonary disease.
Systemic opiates may relieve dyspnoea and improve exercise tolerance in patients with chronic obstructive pulmonary disease (COPD). Small doses of inhaled opiates may have similar effects; however, recent studies have shown no benefit. We studied higher doses of inhaled morphine and measured systemic absorption to determine whether any beneficial actions are local or systemic. ⋯ The highest plasma concentration was measured immediately after nebulization, and this decreased steadily in the hour thereafter (p<0.002). There was no correlation between the change in walk distance and the change in plasma morphine concentration after either dose of nebulized morphine. We conclude that higher doses of nebulized morphine do not improve exercise endurance or relieve dyspnoea in patients with chronic obstructive pulmonary disease, and that morphine is rapidly absorbed systemically after inhalation.