Medication use in home care patients with COPD

Effects of appropriate-intensity treadmill exercise on skeletal muscle and respiratory functions in a rat model of emphysema

The number of patients with chronic obstructive pulmonary disease (COPD), a typical respiratory disorder, is rapidly increasing globally. The purpose of this study was to determine the effects of appropriate-intensity treadmill exercise on skeletal muscle and respiratory functions in a rat model of emphysema. Twenty-one Wistar rats were randomly divided into three groups: the sham (SH) group, pulmonary emphysema (PE) group, and emphysema + exercise (EX) group. Cigarette smoke solution and lipopolysaccharide were intratracheally administered for 4 weeks in the PE and EX groups. The rats in the EX group were made to run on treadmills in the latter 2 weeks of the experiment. Lung tissue was stained with anti-macrophage antibodies; the specific force (contractile force per unit cross-sectional area) of the diaphragm and hind-limb muscles was measured, and blood was analyzed for serum cytokine levels. Many macrophages were observed in the lung tissue of the PE group. In the EX group, the population of macrophages was smaller, and the specific force of the diaphragm and extensor digitorum longus muscles was higher than in the PE group. Moreover, the degree of inflammation in the pulmonary tissue was reduced in the EX group. These results suggest that adaptive exercise may improve not only respiratory and muscle functions but also inflammation of the pulmonary tissue associated with emphysema.

The effects of hypoventilation disorder on physiological and biochemical properties of the hindlimb muscles

The purpose of this study was to determine the physiological and biochemical properties of hindlimb muscles after hypoventilation (HPO) induced by bilateral phrenic nerve denervation. Male Wistar rats (10 weeks-old) underwent HPO by the phrenic nerve denervation at the cervical level or sham surgery. Analyses were performed 4, 8, and 12 weeks after the surgery. The myosin heavy chain (MHC) isoform profile and in vitro isometric contractile properties of the soleus (SOL) and extensor digitrum longus muscles (EDL) were analyzed. From the postoperative period, HPO induced characteristic changes in SpO2 such as hypoventilation disorder. After 12 weeks, significant increases in MHC1 and significant decreases in MHC2a were observed in the MHC isoform composition in SOL. Moreover, significant increases in MHC2a and significant decreases in MHC2b were also observed in the MHC isoform composition in EDL muscles in the HPO compared with sham (SHM) group. In our study, the tidal volume after unilateral phrenic nerve denervation decreased by approximately 12%, and that after bilateral phrenic nerve denervation decreased by approximately 35%. We concluded that the reduction in behavioral activity levels in the HPO group may have resulted in changes of the peripheral skeletal muscles as a result of disuse atrophy.

Survival on long-term oxygen therapy in chronic airflow limitation: from evidence to outcomes in the routine clinical setting

BACKGROUND

Two previous randomized controlled trials (RCT) demonstrated that the administration of long-term oxygen therapy (LTOT) improved survival in selected patients with hypoxic chronic obstructive pulmonary disease (COPD) or chronic airflow limitation (CAL).

AIMS

The aim of the present study was to investigate whether the survival of CAL patients prescribed LTOT at Flinders Medical Centre (FMC) was gender and age related, and equivalent to that of the previous RCT.

METHODS

A list of patients prescribed domiciliary oxygen therapy for CAL at FMC was generated from Respiratory Unit records and hospital financial records for the supply of this therapy. Survival was compared with that reported for the original RCT, and for Swedish and Belgian COPD patients. Factors influencing survival were studied.

RESULTS

Five hundred and five (249 males, 256 females) patients were prescribed LTOT for CAL at FMC during the study period and included in the survival analysis. The patients were elderly with multiple comorbidities. Survival was less than for the control arms of the previous RCT (apart from the Medical Research Council Working Party (MRC) female group) but comparable with recent overseas data. Overall crude survival was 75.1%, 51.3%, 18.9% and 1.1% at 1, 2, 5 and 10 years respectively. Females experienced longer survival than males. Multivariate analysis indicated that age, forced expiratory volume in 1 s, body mass index (BMI) and the number of comorbidities were prognostic indicators for females; BMI was a prognostic indicator for males. A survival advantage existed for females using at least 19 h concentrator oxygen per day.

CONCLUSIONS

In routine practice, survival of unselected CAL patients with multiple comorbidities is less than that reported in the original RCT.