The American review of respiratory disease
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Am. Rev. Respir. Dis. · Feb 1990
Randomized Controlled Trial Comparative Study Clinical TrialBreath-stacking increases the depth and duration of chest expansion by incentive spirometry.
Although the objective of incentive spirometry is to achieve and hold high lung volumes, many patients with pain or weakness are unable to sustain the effort needed to perform effective exercises. We questioned whether using a one-way valve to prevent exhalation would allow rest between inspiratory efforts and cause volume to cumulate during successive tidal efforts, improving both the depth and duration of the inspiratory maneuver. We studied 26 cooperative but naive patients recovering from surgery, trauma, or critical illness whose pain or weakness impaired ability to achieve and sustain deep inspiration. ⋯ When compared with IC, "breath stacking" (valved) maneuvers increased inspired volume by an average of 15 to 20% (p less than 0.05). More importantly, there was a severalfold increase in the time over which high lung volume was sustained (p less than 0.001). Our results indicate that one-way valving helps to achieve and sustain deep inspiration, even in uncoached patients.
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Am. Rev. Respir. Dis. · Oct 1989
Randomized Controlled Trial Comparative Study Clinical TrialUse and misuse of metered-dose inhalers by patients with chronic lung disease. A controlled, randomized trial of two instruction methods.
Metered-dose inhalers are often used incorrectly by patients with chronic airflow obstruction, and there is a lack of controlled studies designed to evaluate methods to teach the correct use of these devices. Therefore, we screened 100 consecutive stable outpatients for correct or incorrect inhaler use and then conducted a randomized trial of two methods to teach correct use. Patients were classified as correct or incorrect users with a modified metered-dose inhaler containing a thermistor that detected inspiration, inhaler activation, and the duration of breath-holding. ⋯ For all subjects, the proportion using correct technique declined over time, particularly for incorrect users. We also examined a series of patient characteristics, obtained by questionnaire and spirometry, to determine whether they could be used in the clinical setting to identify incorrect users. By discriminant analysis, a group of four variables predicted correct metered-dose inhaler use: bronchodilator responsiveness, a history of additional about proper technique, verbal knowledge of the correct inhaler maneuvers, and the patient's perception of whether it is important to use an inhaler.(ABSTRACT TRUNCATED AT 250 WORDS)
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Am. Rev. Respir. Dis. · Jan 1989
Randomized Controlled Trial Clinical TrialCan mild bronchospasm reduce gastroesophageal reflux?
During attacks of asthma, changes in the transdiaphragmatic pressure gradient may impair the antireflux barrier and provoke gastroesophageal reflux (GER). If GER triggers asthma and asthma causes GER, a vicious circle could arise with an increase in the severity of asthma symptoms. The aim of this investigation was to determine whether postprandial reflux in asthmatics with GER disease is increased during histamine-induced bronchospasm and also if theophylline increases GER during provoked episodes of bronchospasm. ⋯ GER was not more pronounced during the provoked bronchospasm period irrespective of theophylline treatment or not. It seems unlikely that mild bronchospasm provokes reflux in patients with asthma and GER. It would appear that mild bronchospasm is rather protective against gastroesophageal reflux.
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Am. Rev. Respir. Dis. · Sep 1987
Randomized Controlled Trial Comparative Study Clinical TrialA prospective study of lung water measurements during patient management in an intensive care unit.
We prospectively evaluated a protocol that included extravascular thermal volume (ETV) as a measure of extravascular lung water (EVLW) instead of pulmonary artery wedge pressure (Ppaw) measurements to guide the hemodynamic management of 48 critically ill patients. Patients were randomized to either a protocol management (PM), or to a routine management (RM) group. In the RM group, EVLW measurements were unknown to the primary care physicians. ⋯ Mortality for the groups as a whole was similar, but was significantly better (p less than 0.05) for PM patients with initially high EVLW and normal Ppaw (predominantly patients with sepsis or the adult respiratory distress syndrome). For both groups, patients with an initial EVLW greater than 14 ml/kg had a significantly greater mortality than did those with a lesser amount of EVLW: 13 of 15 (87%) versus 13 of 32 (41%), p less than 0.05. We conclude that management based on a protocol using EVLW measurements is safe, may hasten the resolution of pulmonary edema, and may lead to improved outcome in some critically ill patients.
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Am. Rev. Respir. Dis. · Apr 1987
Randomized Controlled Trial Comparative Study Clinical TrialRespiratory stimulants and sleep periodic breathing at high altitude. Almitrine versus acetazolamide.
We studied the effects of almitrine, acetazolamide, and placebo on the hypoxic ventilatory response (HVR), sleep periodic breathing, and arterial oxygen saturation (SaO2) in 4 healthy climbers. In a laboratory on Denali (Mt. McKinley) at 4,400 m (PB = 440 mm Hg), we used a double-blind, randomized, three-way crossover design. ⋯ The HVR (delta VE/delta SaO2%) was doubled with almitrine (p less than 0.05), but unchanged with acetazolamide. The HVR was positively related to periodic breathing (p less than 0.05). We conclude that periodic breathing during sleep at high altitude is related to the hypoxic ventilatory response, and that acetazolamide is a superior agent to almitrine for ameliorating periodic breathing.