Compressor/nebulizers differences in the nebulization of corticosteroids. The CODE study (Corticosteroids and Devices Efficiency)

Background. Nebulization is a common method of medical aerosol generation and it is largely used by adults and children all over the world, both for emergency treatment of acute illness and for long-term home treatment of lung diseases. The aim of this study was to determine the differences in nebulization of inhaled corticosterolds among four representative types of compressor/nebulizers. Methods: Twelve compressor/jet nebulizers from four commercial sources were studied (three for each type): Clenny (MEDEL), Turbo Boy/LC Plus (PARI), Nebula Nuovo/MB5 (MARKOS MEFAR) and Maxaer (ARTSANA) compressor/Sidestream (Medic-Aid Ltd.) nebulizer. We compared the required time for the treatment (nebulization time), output/minutes, compressor pressures, and aerosol characteristics of inhaled corticosteroids: Beclomethasone dipropionate, Flunisolide, Fluticasone propionate and Budesonide. Results: Nebulization Times showed a significant difference between nebulizer and inhaled corticosteroids for Clenny, Turbo Boy, and Maxaer. A considerable difference in the output of nebulized drugs was observed through the compressors/nebulizers. MMAD of all inhaled corticosteroids was significantly different among the four nebulizers. The percentage of particles 90%), whereas with flunisolide was good only for Clenny (98.8%) and Maxaer (96.3%), and with fluticasone only for Clenny (98%), Turbo Boy (99.1%), and Maxaer (86%). Also percentage of particles < 2 pm showed significant variability among the devices. Conclusions: Our results clearly demonstrate that compressor/nebulizer unit plays a key role in the effectiveness of the treatment during inhaled corticosteroid t herapy, and that several differences exist in the performance of the different nebulizers studied. Therefore, the device has the same importance of the compound to reach the best clinical response in the inflammatory diseases of the lower airways

Effect of Postural Variations on Carbon Monoxide Diffusing Capacity in Healthy Subjects and Patients with Chronic Obstructive Pulmonary Disease

Background: The scientific literature does not supply enough information about the effects of postural changes on diffusing lung capacity for carbon monoxide (DL(CO)) in patients with chronic obstructive pulmonary disease (COPD), in particular regarding the prone position. Objectives: We evaluated posture-related changes in DL(CO) in healthy subjects and in COPD patients in order to especially assess how prone posture affects gas exchange. Methods: In this cross-sectional study, DL(CO) was measured in 10 healthy subjects and 30 COPD patients in standing, seated, supine and prone positions. Results: In healthy individuals, DL(CO) tended to improve from the upright to the supine position (21.42 +/- 2.90 and 26.07 +/- 5.11 ml/min/mm Hg, respectively); in the same group, changing the position from upright to prone also caused significant improvements in DL(CO) (absolute value, 21.42 +/- 2.90 vs. 24.80 +/- 4.39 ml/min/mm Hg, p < 0.05, or percent of predicted, 78.58 +/- 11.12 vs. 91.44 +/- 13.23, p < 0.05) and in DL(CO) proportional to alveolar volume (DL(CO)/VA; 4.52 +/- 0.57 vs. 5.66 +/- 1.48 ml/min/mm Hg/l, p < 0.05). No significant differences in DL(CO) have been observed in COPD patients from the standing to the prone position. Multivariate linear regression models showed that the posture-related changes in DL(CO), DL(CO) expressed as percent of predicted and in DL(CO)/VA are directly correlated with the transition from upright/sitting to supine/prone. Conclusions: In healthy subjects, the effect of postural changes on DL(CO) could be explained by a more homogeneous perfusion, whereas the lack of variations in COPD patients could be attributed to the increased rigidity of lung capillaries, which could represent an early sensitive marker of damage of the alveolar capillary interface in these patients. Copyright (c) 2008 S. Karger AG, Base

Mixed Acid-Base Disorders, Hydroelectrolyte Imbalance and Lactate Production in Hypercapnic Respiratory Failure: The Role of Noninvasive Ventilation

Background: Hypercapnic Chronic Obstructive Pulmonary Disease (COPD) exacerbation in patients with comorbidities and multidrug therapy is complicated by mixed acid-base, hydro-electrolyte and lactate disorders. Aim of this study was to determine the relationships of these disorders with the requirement for and duration of noninvasive ventilation (NIV) when treating hypercapnic respiratory failure. Methods: Sixty-seven consecutive patients who were hospitalized for hypercapnic COPD exacerbation had their clinical condition, respiratory function, blood chemistry, arterial blood gases, blood lactate and volemic state assessed. Heart and respiratory rates, pH, PaO2 and PaCO2 and blood lactate were checked at the 1st, 2nd, 6th and 24th hours after starting NIV. Results: Nine patients were transferred to the intensive care unit. NIV was performed in 11/17 (64.7%) mixed respiratory acidosis–metabolic alkalosis, 10/36 (27.8%) respiratory acidosis and 3/5 (60%) mixed respiratory-metabolic acidosis patients (p = 0.026), with durations of 45.169.8, 36.268.9 and 53.364.1 hours, respectively (p = 0.016). The duration of ventilation was associated with higher blood lactate (p,0.001), lower pH (p = 0.016), lower serum sodium (p = 0.014) and lower chloride (p = 0.038). Hyponatremia without hypervolemic hypochloremia occurred in 11 respiratory acidosis patients. Hypovolemic hyponatremia with hypochloremia and hypokalemia occurred in 10 mixed respiratory acidosis–metabolic alkalosis patients, and euvolemic hypochloremia occurred in the other 7 patients with this mixed acid-base disorder

Assessment of right ventricular function by tissue Doppler imaging in patients with chronic obstructive pulmonary disease

Background. The evaluation of right ventricular function is clinically useful in patients with chronic obstructive pulmonary disease (COPD because the presence of right ventricular failure has prognostic implications. All invasive and non invasive techniques evaluating right ventricular performance have important limitations due to right ventricular complex geometry. The introduction of Doppler measurement of myocardial wall velocities (tissue Doppler imaging, TDI) and the recently developed strain rate (SR) imaging technique have made possible a more adequate assessment of global and regional systolic and diastolic right ventricular function. Our purpose was: 1) to compare TDI/SR parameters with conventional indices evaluating right ventricular function; 2) to assess the correlation among TDI/SR parameters and respiratory function tests . Methods. Twenty-nine patients (age 5313 years) with chronic obstructive pulmonary disease were included in the study. 15 patients had pulmonary artery pressure >35mmHg (group I), 14 patients had pulmonary artery pressure <35mmHg (group II). Sixteen age- and gender-matched healthy subjects who had normal cardiac findings served as controls (group III). Right ventricular ejection fraction (EF), fractional shortening (FS), and tricuspid flow filling parameters (E/A ratio, DT) were determined. Offline analysis of the myocardial velocity data sets was performed using dedicated software (Aplio, Toshiba Corp.). Velocity and strain traces from right ventricular free wall at 3 levels (basal, mid cavity, and apical) were processed from the same wall site in the apical 4-chamber view. Diastolic TDI values (Ew, Aw), peak systolic strain and systolic and diastolic strain rate values were determined. Echocardiographic parameters were evaluated after the respiratory function tests were performed ( FEV1= forced expiratory volume in one second; FEV1/VC = forced expiratory volume in one second / vital capacity; DLCO = single-breath diffusion capacity of the lung for carbon monoxide; DLCO/VA = carbon monoxide diffusion capacity per unit of alveolar volume ) . Results. Measurements of TDI/SR parameters were rapidly obtained with a low inter- and intra-observer variability. Ew/Aw ratio at apical and mid level was lower in Group I and II than in Group III (p<0.005). Peak systolic strain and systolic and diastolic strain rate at apical and mid level were lower in Group I and II than in Group III (p<0.001). Right ventricular EF, FS, E/A ratio, and DT were not different among the three groups. No correlation was found between EF, FS, E/A ratio, DT, and respiratory function tests. A highly significant relationship was shown between peak systolic strain at mid level and DLCO/VA (r=0.67, p<0.001) and peak systolic strain at mid level and FEV1/VC (r=0.69, p<0.001). Conclusion. Thus in COPD patients TDI/SR parameters can determine right ventricular dysfunction that is not shown by conventional echocardiographic indices and is correlated with respiratory function tests

Flow chart of the consecutive COPD patients with acute hypercapnic exhacerbation enrolled in the study.

<p>Flow chart of the consecutive COPD patients with acute hypercapnic exhacerbation enrolled in the study.</p

Assessment of right ventricolar function by strain Doppler echocardiography in patients with chronic obstructive pulmonary disease

The purpose of the current study was to compare right ventricular (RV) myocardial wall velocities (tissue Doppler imaging) and strain rate imaging (SRI) parameters with conventional echocardiographic indices evaluating RV function in chronic obstructive pulmonary disease (COPD) patients. In total, 39 patients with COPD and 22 healthy subjects were included in the current study. Seventeen patients had pulmonary artery pressure 35?mmHg (group II). Tissue Doppler imaging, strain and strain rate (SR) values were obtained from RV free wall (FW) and interventricular septum. Respiratory function tests were performed (forced expiratory volume in one second/vital capacity (FEV1/VC) and carbon monoxide diffusion lung capacity per unit of alveolar volume (DL,CO/VA)). Strain/SR values were reduced in all segments of group II patients compared with group I patients and controls with lowest values at basal FW site. A significant relationship was shown between peak systolic SR at basal FW site and radionuclide RV ejection fraction. A significant relationship was shown between peak systolic SR at basal FW site and DL,CO/VA and FEV1/VC. In conclusion, in chronic obstructive pulmonary disease patients, strain rate imaging parameters can determine right ventricular dysfunction that is complementary to conventional echocardiographic indices and is correlated with pulmonary hypertension and respiratory function tests

Patients demographics and clinical characteristics.

<p>Data expressed as Mean ± Standard Deviation.</p>a<p>Student t-test for unpaired data;</p>b<p>Chi-Squared Test. NIV = non invasive ventilation; BMI = Body Mass Index; SBP = Systolic Blood Pressure; DBP = Diastolic Blood Pressure; FEV₁ = Forced Expiratory Volume; GCS = Glasgow Coma Scale; APACHE II score = Acute physiology and chronic health evaluation II score.</p