Theophylline improves measurements of respiratory muscle efficiency.
نویسندگان
چکیده
To determine the effect of theophylline on respiratory muscle efficiency (RME), 12 normal subjects were given theophylline vs placebo in a double-blind, randomized crossover protocol. Spirometry, resting energy expenditure, minute ventilation, RME and oxygen cost of breathing were measured at baseline, after taking theophylline, and after placebo. RME was calculated by dividing the added work required to breathe through a threshold load by the added energy consumed during loaded breathing. Oxygen cost of breathing was calculated by dividing the increase in oxygen consumption induced by breathing an air/carbon dioxide mixture by the associated increase in minute ventilation. RME increased from 3.3 +/- 1.6% at baseline to 7.9 +/- 3.2% after theophylline (p < 0.01) but did not change significantly after placebo (4.8 +/- 2.4%). Oxygen cost of breathing decreased from 3.9 +/- 2.4 mL O2 per liter at baseline to 1.7 +/- 0.7 mL O2 per liter after theophylline (p < 0.05) but did not change significantly after placebo (2.8 +/- 1.3 mL O2 per liter). Theophylline use was also associated with an 18% increase in minute ventilation (p < 0.01) and a 15.7% increase in resting energy expenditure (p < 0.01). Theophylline improves measured RME and reduces oxygen cost of breathing in normal subjects. These effects are offset by increases in resting energy expenditure and minute ventilation.
منابع مشابه
Theophylline improves acute mountain sickness.
A randomized two-part study was conducted in order to determine the efficacy of theophylline in the treatment of acute mountain sickness during fast ascent to altitudes >2,500 m. Fourteen healthy male subjects participated in a randomized single-blind placebo-controlled crossover study carried out in a decompression chamber (simulated altitude 4,500 m). A second randomized single-blind, placebo...
متن کاملThe Effect of Bunium persicum (Boiss.) B. Fedtsch. Consumption on Metabolic Syndrome Indices, Muscle Strength, and Cardio-respiratory Function in Active Middle-aged Women: A Randomized Clinical Trial
Background: The effect of Bunium persicum (Boiss.) B. Fedtsch. on the metabolic syndrome and physical fitness of active people have been less studied. Objective: The purpose of this study was to investigate the effect of B. persicum consumption on metabolic syndrome indices, muscle strength, and cardio-respiratory function in active middle-aged women. Method: The research method was quasi-e...
متن کاملThe effect of aminophylline on respiratory and limb muscle contractility in man.
The effect of oral aminophylline on respiratory muscle and quadriceps femoris strength was compared with placebo in five normal subjects. A double-blind randomized cross-over protocol, spanning 2-3 wks, was followed. Aminophylline was taken before both placebo and active drug periods to establish correct dosage, to allow tolerance to side-effects to develop, and to keep the two limbs of the stu...
متن کاملEvaluation of Thoracic Kyphosis Angle and Respiratory Functions in Patients with Multiple Sclerosis
Background. Multiple Sclerosis (MS) is a chronic autoimmune demyelinating disease. Muscle weakness, tremors, balance disorders, and gait instability are observed in MS patients. Also, respiratory muscles weakness can lead to decreased respiratory capacity, resulting in pneumonia and acute respiratory failure. Objectives. This study evaluates thoracic kyphosis angle (TKA) and respiratory functi...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Chest
دوره 110 6 شماره
صفحات -
تاریخ انتشار 1996