This study was designed to evaluate the performance of movement detectors (pedometers) in measuring daily activity of patients with chronic lung disease. Three groups of subjects were studied: group 1: 25 patients with stable nonhypercapnic chronic obstructive pulmonary disease (COPD) (forced expiratory volume in one second (FEV1) = 47+/-9% predicted) studied twice, one month apart; group 2: 25 patients with chronic respiratory failure studied before and three months after nasal nocturnal mechanical ventilation; and group 3: 25 normal healthy subjects studied once. The median level of activity in the healthy subjects (group 3) was three times greater than in either group of patients (groups 1 and 2). Activity levels were not correlated with age, sex or employment status. The repeatability of the activity counts in the nonhypercapnic COPD patients was high (intraclass correlation coefficient=0.94) and in these patients activity correlated significantly with FEV1 (r=0.54, p=0.006). In the respiratory failure patients, daytime arterial carbon dioxide pressure (Pa,CO2) improved following nasal nocturnal mechanical ventilation (NMV) (pre NMV: 8.5+/-1.2 kPa; post NMV: 6.2+/-0.5 kPa), health status improved (p<0.004) and daily movement count doubled (p<0.0001). This increase correlated with change in Pa,CO2 (r-0.53, p=0.006), but not with improved health status. We conclude that motion detectors may provide repeatable measures of daily activity that are related to physiological impairment and improvement following treatment. Activity counts appear to be complementary to estimates of exercise limitation obtained using health questionnaires.

We conclude that red blood cell transfusion in anemic patients with COPD leads to a significant reduction of both the minute ventilation and the WOB. In these patients, transfusion may be associated with unloading of the respiratory muscles, but it may also result in mild hypoventilation.

aaChronic respiratory insufficiency (CRI) is caused by a relative imbalance between the capacity of the respiratory muscles and the load placed upon them [1]. Noninvasive mechanical ventilation (NIMV) relieves symptoms of hypoventilation and improves daytime blood gases in CRI. The efficacy of nocturnal mechanical ventilation (nMV) has been convincingly demonstrated in patients with CRI due to restrictive lung and chest wall disorders and neuromuscular diseases [2].Hypoventilation in established CRI is found both during the day while the patient is awake and during sleep in the night. However, compared to daytime, the degree of nocturnal hypoventilation is usually more severe and appears earlier in the clinical course.Traditionally, mechanical ventilation for CRI is commonly used at night [3][4][5][6][7][8]. This is done both because nMV is more convenient to the patients (freeing them for daytime activities), but also because hypoventilation is usually more severe during sleep than during the day [9][10][11]. Indeed, some investigators consider that the sleep disordered breathing itself causes CRI [2,[10][11][12]. Therefore, we performed a prospective case controlled study comparing nMV and daytime mechanical ventilation (dMV) in patients with CRI in order to investigate whether the therapeutic effect of NIMV necessarily depends on the application being nocturnal. Materials and methods PatientsThe hospital in which this study was carried out is a regional referral centre for patients with CRI. All patients with CRI referred for mechanical ventilation to the hospital within 1 yr were assessed for recruitment to the study. Thus, 34 patients were enrolled. During the study the patients were not on long-term oxygen therapy. The patient's diagnoses and characteristics are presented in table 1. The protocol was approved by our ethical review committee and all subjects gave their informed written consent to participate. MeasurementsBaseline measurements were performed prior to the runin period of mechanical ventilation; the normal values for lung function data were those of the European Respiratory Society [13]. We measured spirometry and whole body plethysmography (Masterlab, Jäger, Würzburg, Germany). Peak static inspiratory mouth pressure (PI,max) was performed using a piezo-electric pressure sensor. PI,max was measured at residual volume at least five times, until a reproducible value was obtained; the maximum value obtained In order to test whether the efficacy of NIMV depends on it being applied during sleep, we conducted a prospective case-controlled study comparing daytime mechanical ventilation (dMV) in awake patients with nocturnal mechanical ventilation (nMV) given in equal quantities.We enrolled 34 clinically stable patients (age 56.1±12.1 yrs, 20 females, 14 males) with CRI due to restrictive lung and chest wall disorders and neuromuscular disease. Using a prospective case-control design, matched subjects were allocated alternately to dMV and nMV.After 1 month of NIMV there was considerable symptomatic im...

Acutely extubated patients in whom oxygen therapy is indicated may profit from eITO. This new technique works immediately and is thus an effective short-term intervention of potential value in the intensive care unit.