Our Editor's Choice paper this month is by Rubin and colleagues. It relates to the role of guaifenesin as a cough suppressant and expectorant in adolescents and adults with an acute respiratory tract infection. This was an 8-day, multi-center, clinical trial conducted to study the effect of extended-release guaifenesin. There were no significant dif-ferences between guaifenesin and placebo groups for sputum volume, percent solids, interfacial tension, elasticity, viscos-ity, or mechanical impedance. As O'Connell indicates in his editorial, the FDA's progressive requirements in demonstrat-ing proof of efficacy for new over the counter medications will, in time, increase pressure to show efficacy of already available over-the-counter medications that entered the mar-ket prior to the current requirements
Lellouche et al assessed the humidification performances of passive and active heat and moisture exchangers (HME). In an in vitro study, they evaluated a device with passive and active humidification properties, and 2 passive hydrophobic/hygroscopic HMEs. The devices were tested at 3 ambient temperatures and 2 minute ventilation settings. In addition to the bench study, they clinically measured hygrometry of in-spired gases in 2 clinical studies. In these studies, both passive and active HME had stable humidification performances with negligible influence of ambient temperature and minute ven-tilation. An important point made by Wilkes in his editorial is that, what is really needed is the definitive study to determine the optimum level of humidification required for mechanical ventilation.
The Nationwide Inpatient Sample was used by Rahul et al to identify patients discharged with a principal diag-nosis of acute asthma. The proportion of admissions where invasive mechanical ventilation was used decreased from 1.4% in 2000 to 0.73% in 2008, but noninvasive ventilation (NIV) increased from 0.3% to 1.9%. Hospital mortality was unchanged over this time. Venkateshiah points out that ran-domized controlled trials are necessary to address the man-agement of asthma exacerbations. The efficacy of NIV for acute asthma is yet to be determined.
A meta-analysis was conducted by Tian and colleagues related to tiotropium versus placebo for inadequately con-trolled asthma. There were 6 trials that met the inclusion criteria. The results of the analysis suggest that addition of tiotropium to standard treatment has significantly improved lung function without increasing adverse events in patients with inadequately controlled asthma.
Stoller and colleagues hypothesized that respiratory ther-apists (RTs) could improve the detection rate of individuals with alpha-1 antitrypsin (AAT) deficiency. They found that a program to educate RTs about AAT deficiency was associated with referral of patients for AAT deficiency testing and higher rates of detecting individuals with severe deficiency of AAT.
The aim of the study by Mueller et al was to evaluate 3 different Acapella devices and a water bottle positive expira-tory pressure device, to determine the optimal device and set-ting for effective secretion removal. They were able to iden-tify the optimal setting for each device. They also suggest that the Acapella device might be more efficient for secretion mobilization than the water bottle method.
Guimarães et al evaluated the acute mechanical effects and sputum clearance of an expiratory rib cage compression (ERCC) protocol. Sputum production and respiratory me-chanics were evaluated in mechanically ventilated subjects submitted to 2 interventions. Although ERCC increased ex-piratory flow, it had no clinically relevant effects in improv-ing the sputum production and respiratory mechanics.
The objective of the study by Longest and colleagues was to improve the delivery of aerosol during mechanical ventila-tion by redesigning circuit components using a streamlining approach. The streamlining approach eliminates sharp chang-es in flow direction and tubing diameter that lead to flow disruption. They found that streamlined components can im-prove the delivery of aerosols during mechanical ventilation.
Wibmer et al evaluated the effects of nasal positive expiratory pressure on dynamic hyperinflation and 6-min walk test in subjects with COPD. They found that the use of flow-dependent expiratory pressure, applied with a nasal mask and a positive expiratory pressure device, can promote reduction of dynamic hyperinflation during walking.
A meta-analysis was conducted by Ricci and colleagues to evaluate physical training and NIV in stable subjects with COPD. A similar effect between NIV and placebo was ob-served for the outcomes considered despite differences be-tween studies. However, subjects experienced a relevant and significant improvement after rehabilitation for most of the outcomes considered.
Teopompi et al investigated the effect of the fat-free mass (FFM) on maximal exercise capacity in subjects with COPD, and the relationship with changes in operational lung vol-umes during exercise. They found that FFM depletion plays a part in the reduction of exercise capacity of patients with COPD patients, regardless of dynamic hyperinflation, and is associated with poor cardiovascular response to exercise and to leg fatigue, but not to dyspnea.
Using a simulation model, L'Her et al evaluated manual ventilation and an automatic manually-triggered device. They found that the use of an automatic, manually-triggered device might improve ventilation efficiency and decrease the risk of pulmonary over-distension, while decreasing the ventilation rate.
Adams et al examined patterns of intubation by an emer-gency airway team at a large academic center. This was a retrospective analysis of 1,482 intubations performed by an emergency airway team over a 3 y period. They found that emergency airway service utilization is highest during daytime hours, with seasonal variations comprised of higher consults in the winter and lower consults in the summer.
The prevalence of supranormal pulmonary function tests (PFTs) between a military and non-military cohort was as-sessed by Morris and colleagues. They found no significant difference in the proportion of supranormal to normal PFTs in an active duty versus non-active duty population of the same age range. Thus, no assumption should be made that supranormal PFTs are more common in military personnel. Interpretation of normal PFTs in active duty personnel under-going evaluation should not differ from any typical patient.
Agarwal and colleagues conducted a randomized trial comparing the diagnostic yield of rigid and semirigid tho-racoscopy in undiagnosed pleural effusions. Rigid thoraco-scopy was found to be superior to semirigid thoracoscopy overall, but the diagnostic yield was similar if pleural biopsy could be successfully performed.
Depression and COPD share some clinical features, such as reduced physical activity and impaired nutritional status. The aim of the study by Di Marco et al was to evaluate max-imal and daily physical activity and the nutritional status of subjects with COPD affected or not by depression. They found that subjects with COPD who are depressed have a reduced daily and maximal exercise capacity compared to those who are not depressed.
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