American journal of respiratory and critical care medicine
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Am. J. Respir. Crit. Care Med. · Mar 1996
Randomized Controlled Trial Comparative Study Clinical TrialInhaled bronchodilators reduce dynamic hyperinflation during exercise in patients with chronic obstructive pulmonary disease.
Dynamic hyperinflation (DH) is a major pathophysiologic consequence of airflow limitation during exercise in patients with chronic obstructive pulmonary disease (COPD) and an important contributing factor to breathlessness. In this study we aimed to examine the effect of inhaled beta agonist therapy on DH during exercise in these patients and the relationship between changes in DH and breathlessness. In 13 COPD patients (mean age 65.1 +/- 2.0, FEV1 1.20 +/- 0.17, FEV1/FVC 40 +/- 3) we measured pulmonary function tests, exercise breathlessness by Borg score, and exercise flow volume and pressure volume loops on two separate days. ⋯ The relationships between delta Borg, delta resting volumes, and flow rates were not significant. We conclude that in patients with COPD, inhaled bronchodilator reduces exercise DH and improves inspiratory pressure reserve and neuroventilatory coupling. Changes in DH and neuroventilatory coupling were the main determinants of reduced breathlessness.
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Am. J. Respir. Crit. Care Med. · Mar 1996
Randomized Controlled Trial Comparative Study Clinical TrialDirect comparison of inhaled nitric oxide and aerosolized prostacyclin in acute respiratory distress syndrome.
Inhalation of NO and aerosolization of PGI2 have been suggested to achieve selective pulmonary vasodilation and improvement of arterial oxygenation in patients with ARDS. We directly compared these two modes of transbronchial vasodilator therapy in 16 ARDS patients mechanically ventilated (mean lung injury score [1] 2.75 +/- 0.05). Patients were randomized to receive either first NO and then PGI2, or vice versa. ⋯ Two further patients displayed an improvement of arterial oxygenation in response to either NO or PGI2. NO decreased mean pulmonary artery pressure from 34.8 +/- 2.2 to 33.0 +/- 1.8 mm Hg, and PGI2 from 35.0 +/- 2.2 to 31.9 +/- 1.7 mm Hg (p<0.05). We conclude that individually titrated doses of inhaled NO and aerosolized PGI2 effect selective pulmonary vasodilation and redistribute blood-flow from shunt-areas to well-ventilated regions with nearly identical efficacy profiles.
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Am. J. Respir. Crit. Care Med. · Mar 1996
Randomized Controlled Trial Comparative Study Clinical TrialSedation of critically ill patients during mechanical ventilation. A comparison of propofol and midazolam.
Propofol (P) and midazolam (M) are frequently given by continuous infusion for sedation in critically ill, mechanically ventilated patients. We compared these drugs with regard to: (1) time-to-awaken; (2) reproducibility of bedside assessments of level of sedation; (3) time-to-sedation; and (4) change in oxygen consumption (V O2) from awake to sedated state. Seventy-three patients were prospectively randomized to receive either P (n=37) or M (n=36). ⋯ Blinded versus unblinded observations had excellent correlation. Average time to sedate and decrease in V O2 were not different. We conclude that in this patient population: (1) both P and M achieved optimal sedation in a large fraction of patients when administered by specified dosing protocols; (2) P had a faster, more reliable, wake-up time; (3) assessments of time-to-awaken were objective and reproducible; (4) time to sedation was not significantly different; (5) V O2 decreased similarly with both.