No abstract

One of the most important determinants of physical and mental well-being of people with chronic obstructive pulmonary disease (COPD) is participation in physical activity. The ability to alter the sensation of dyspnoea during exercise may improve both exercise duration and intensity. Despite the low density, inert nature, strong safety profile and multiple applications of helium gas, the potential benefit of helium-oxygen gas mixtures as an adjunct therapy to modify disease symptoms and exercise capabilities in obstructive lung diseases has only recently been explored. This is a systematic review of the available peer-reviewed evidence exploring whether symptom modification (perceived levels of dyspnoea) and exercise performance in COPD (either intensity or duration of work) are modified by inhalation of Heliox. Eight experimental studies met inclusion for this review. A variety of methodologies and outcome variables were used negating metaanalysis and hampering direct comparison between interventions. Overall, there was high level of evidence with a low risk of bias supporting Heliox's effectiveness in improving the intensity and endurance of exercise when compared to room air for people with COPD. Little conclusive evidence was found to determine whether Heliox altered the sensation of dyspnoea during exercise.

Rapid intravenous (iv) infusion of 0.9% saline alters respiratory mechanics in healthy subjects. However, the relative cardiovascular and respiratory effects of bolus iv crystalloid vs. colloid are unknown. Six healthy male volunteers were given 30 ml/kg iv 0.9% saline, 4% albumin, and 5% glucose at a rate of 100 ml/min on 3 separate days in a double-blinded, randomized crossover study. Impulse oscillometry, spirometry, lung volumes, diffusing capacity (DLCO), and blood samples were measured before and after fluid administration. Lung ultrasound B-line score (indicating interstitial pulmonary edema) and Doppler echocardiography indices of cardiac preload were measured before, midway, immediately after, and 1 h after fluid administration. Infusion of 0.9% saline increased small airway resistance at 5 Hz (P = 0.04) and lung ultrasound B-line score (P = 0.01) without changes in Doppler echocardiography measures of preload. In contrast, 4% albumin increased DLCO, decreased lung volumes, and increased the Doppler echocardiography mitral E velocity (P = 0.001) and E-to-lateral/septal e' ratio, estimated blood volume, and N-terminal pro B-type natriuretic peptide (P = 0.01) but not lung ultrasound B-line score, consistent with increased pulmonary blood volume without interstitial pulmonary edema. There were no significant changes with 5% glucose. Plasma angiopoietin-2 concentration increased only after 0.9% saline (P = 0.001), suggesting an inflammatory mechanism associated with edema formation. In healthy subjects, 0.9% saline and 4% albumin have differential pulmonary effects not attributable to passive fluid filtration. This may reflect either different effects of these fluids on active signaling in the pulmonary circulation or a protective effect of albumin.

Recently, buffered salt solutions and 20% albumin (small volume resuscitation) have been advocated as an alternative fluid for intravenous resuscitation. The relative comparative efficacy and potential adverse effects of these solutions have not been evaluated. In a randomized, double blind, cross-over study of six healthy male subjects we compared the pulmonary and hemodynamic effects of intravenous administration of 30 ml/kg of 0.9% saline, Hartmann's solution and 4% albumin, and 6 ml/kg of 20% albumin (albumin dose equivalent). Lung tests (spirometry, ultrasound, impulse oscillometry, diffusion capacity, and plethysmography), two- to three-dimensional Doppler echocardiography, carotid applanation tonometry, blood gases, serum/urine markers of endothelial, and kidney injury were measured before and after each fluid bolus. Data were analyzed with repeated measures ANOVA with effect of fluid type examined as an interaction. Crystalloids caused lung edema [increase in ultrasound B line ( P = 0.006) and airway resistance ( P = 0.009)], but evidence of lung injury [increased angiopoietin-2 ( P = 0.019)] and glycocalyx injury [increased syndecan ( P = 0.026)] was only observed with 0.9% saline. The colloids caused greater left atrial stretch, decrease in lung volumes, and increase in diffusion capacity than the crystalloids, but without pulmonary edema. Stroke work increased proportionally to increase in preload with all four fluids ( R2 = 0.71). There was a greater increase in cardiac output and stroke volume after colloid administration, associated with a reduction in afterload. Hartmann’s solution did not significantly alter ventricular performance. Markers of kidney injury were not affected by any of the fluids administrated. Bolus administration of 20% albumin is both effective and safe in healthy subjects. NEW & NOTEWORTHY Bolus administration of 20% albumin is both effective and safe in healthy subjects when compared with other commonly available crystalloids and colloidal solution.

Our study measures effects of the Spirometry Learning Module (SLM) on health-care professionals’ knowledge of spirometry test quality and perceived confidence, experience, and understanding of spirometry measurements and interpretation. Professionals from both primary and hospital-based settings enrolled in the SLM, a training model focusing on spirometry test performance and interpretation, including an online interactive learning component and a face-to-face workshop. Participants were asked to submit patient spirometry assessment worksheets for feedback on quality and interpretation. Data were collected at baseline, SLM completion (20 weeks), and 12 months after SLM completion. Knowledge of spirometry test quality was evaluated with questions relating to five case-based assessments of common spirometric patterns. Perceived confidence, experience, and knowledge in test performance were measured using a 7-point Likert scale. The Friedman test combined with post hoc analyses were used to analyse differences between baseline, 20-week, and 12-month post completion. Qualitative interviews were performed to assess reasons for non-completion. Of the 90 participants enrolled in the SLM and consented to research, 48 completed the 20-week measurement and 11 completed the 12-month measurement. Statistically significant improvements were detected in all outcomes in participants who completed the SLM to 20-week and 12-month follow-up assessments (all p values < 0.01). Barriers to completion were limited access to patients requiring spirometry, high clinic workload, and having a different spirometer at the workplace compared to the one used during SLM demonstrations. Our data suggest that participants’ confidence, experience, and knowledge regarding spirometry may improve through SLM completion.