Year in Review 2014: Aerosol Delivery Devices.

After centuries of discoveries and technological growth, aerosol therapy remains a cornerstone of care in the management of both acute and chronic respiratory conditions. Aerosol therapy embraces the concept that medicine is both an art and a science, where an explicit understanding of the science of aerosol therapy, the nuances of the different delivery devices, and the ability to provide accurate and reliable education to patients become increasingly important. The purpose of this article is to review recent literature regarding aerosol delivery devices in a style that readers of Respiratory Care may use as a key topic resource.

How does adding and removing liquid from socket bladders affect residual-limb fluid volume?

Adding and removing liquid from socket bladders is a means for people with limb loss to accommodate residual-limb volume change. We fit 19 people with transtibial amputation using their regular prosthetic socket with fluid bladders on the inside socket surface to undergo cycles of bladder liquid addition and removal. In each cycle, subjects sat, stood, and walked for 90 s with bladder liquid added, and then sat, stood, and walked for 90 s again with the bladder liquid removed. The amount of bladder liquid added was increased in each cycle. We used bioimpedance analysis to measure residual-limb fluid volume. Results showed that the preferred bladder liquid volume was 16.8 +/- 8.4 mL (mean +/- standard deviation), corresponding with 1.7% +/- 0.8% of the average socket volume between the bioimpedance voltage-sensing electrodes. Residual-limb fluid volume driven out of the residual limb when bladder liquid was added was typically not recovered upon subsequent bladder liquid removal. Of the 19 subjects, 15 experienced a gradual residual-limb fluid volume loss over the test session. Care should be taken when implementing adjustable socket technologies in people with limb loss. Reducing socket volume may accentuate residual-limb fluid volume loss.

The science guiding selection of an aerosol delivery device.

Aerosol therapy continues to be considered as one of the cornerstones of the profession of respiratory care, even after 60 years. Aerosol therapy serves as a critical intervention for both exacerbations and chronic maintenance for a variety of respiratory care conditions. Aerosol therapy uniquely blends both the art and science of medicine together to produce the practical and necessary clinical outcomes for patients with respiratory diseases. This review was presented as part of the New Horizons Symposium on how to guide the scientific selection of an appropriate aerosol device.

Thinking outside the box: moving the respiratory care profession beyond the hospital walls.

For centuries, hospitals have served as the cornerstone of the United States healthcare system. Just like the majority of the general population, the respiratory care profession was born inside the hospital walls, just over 6 decades ago. While the knowledge, skills, and attributes of the respiratory therapist are critically necessary in acute care settings, the profession must move itself to a stronger position across the entire continuum of care of patients with acute and chronic cardiopulmonary diseases within the next several years to stay ahead of the curve of healthcare reform. In this paper, based on the 28th annual Philip Kittredge Memorial Lecture, I will examine the necessary strategies and values that the profession of respiratory care will need to successfully embrace to "think outside the box" and move the profession beyond the hospital walls for patient- and outcomes-focused, sustainable impact in the future healthcare delivery system.

Respiratory care year in review 2012: Asthma and sleep-disordered breathing.

Asthma has long been recognized as a common respiratory disease, and the recognition of sleep-disordered breathing is becoming more prevalent. Patients with these disorders are commonly seen by clinicians caring for patients with respiratory disease. There is also much academic interest in asthma and sleep-disordered breathing. The purpose of this paper is to review the recent literature related to asthma and sleep-disordered breathing in a manner that is most likely to have interest to the readers of Respiratory Care.

How do sock ply changes affect residual-limb fluid volume in people with transtibial amputation?

The purpose of this research was to investigate the influence of sock addition and removal on residual-limb fluid volume in people using prosthetic limbs. We used bioimpedance analysis to measure residual-limb extracellular fluid volume on 28 transtibial amputee subjects during 30 min test sessions. Upon addition of a one-ply polyester sock, residual-limb fluid volume changes ranged from -4.0% to 0.8% (mean -0.9 +/- 1.3%) of the initial limb fluid volume. Changes for sock removal ranged from -1.2% to 2.8% (mean 0.5 +/- 0.8%). Subjects who reduced in fluid volume with both addition and removal of a sock and subjects with high positive ratios between the fluid-volume loss upon sock addition and gain upon sock removal (high add/remove [AR] ratios) tended to have arterial disease, were obese, and were smokers. Subjects with low positive AR ratios, subjects who increased in fluid volume both with sock addition and removal, and a single subject who increased in fluid volume with sock addition and decreased with sock removal tended to be nonsmokers and either individuals in good health without complications or individuals without arterial problems. Results are relevant for the anticipation of limb volume changes during prosthetic fitting and toward the design of adjustable-socket technologies.

Post-doffing residual limb fluid volume change in people with trans-tibial amputation.

BACKGROUND: Residual limb volume may change after doffing, affecting the limb shape measured and used as a starting point for socket design. OBJECTIVES: The purpose of this study was to compare residual limb fluid volume changes after doffing for different test configurations. STUDY DESIGN: The study was a repeated measures experimental design with three conditions (Sit, Liner, and Walk). METHODS: Residual limb fluid volume on 30 people with trans-tibial amputation was measured using bioimpedance analysis. Three tests were conducted--Sit: sit for 10 minutes, remove the prosthesis, socks and liner, sit for 10 minutes; Liner: sit for 10 minutes, remove the prosthesis and socks but not the liner, sit for 10 minutes; Walk: conduct sit, stand and walk activities for 30 minutes, remove the prosthesis, socks and liner, sit for 10 minutes. RESULTS: The percentage fluid volume increase after doffing was significantly higher for Walk (2.8%) than for Sit (1.8%) (p = 0.03). The time to achieve a maximum or stable fluid volume was shorter for Liner (4.3 min) than for Sit (6.6 min) (p = 0.03). CONCLUSIONS: Activity before doffing intensified the post-doffing limb fluid volume increase. Maintaining a liner after doffing caused limb fluid volume to stabilize faster than removing the liner. Clinical relevance To minimize residual limb volume increase before casting or imaging, practitioners should have patients sit with their prosthesis donned for 10 minutes. Leaving a liner on the residuum will not reduce the post-doffing volume increase, but it will help to more quickly achieve a consistent limb fluid volume.

The role of nebulized therapy in the management of COPD: evidence and recommendations.

Current guidelines recommend inhalation therapy as the preferred route of drug administration for treating chronic obstructive pulmonary disease (COPD). Previous systematic reviews in COPD patients found similar clinical outcomes for drugs delivered by handheld inhalers - pressurized metered-dose inhalers (pMDIs), dry powder inhalers (DPIs) - and nebulizers, provided the devices were used correctly. However, in routine clinical practice critical errors in using handheld inhalers are highly prevalent and frequently result in inadequate symptom relief. In comparison with pMDIs and DPIs, effective drug delivery with conventional pneumatic nebulizers requires less intensive patient training. Moreover, by design, newer nebulizers are more portable and more efficient than traditional jet nebulizers. The current body of evidence regarding nebulizer use for maintenance therapy in patients with moderate-to-severe COPD, including use during exacerbations, suggests that the efficacy of long-term nebulizer therapy is similar, and in some respects superior, to that with pMDI/DPIs. Therefore, despite several known drawbacks associated with nebulized therapy, we recommend that maintenance therapy with nebulizers should be employed in elderly patients, those with severe disease and frequent exacerbations, and those with physical and/or cognitive limitations. Likewise, financial concerns and individual preferences that lead to better compliance may favor nebulized therapy over other inhalers. For some patients, using both nebulizers and pMDI/DPI may provide the best combination of efficacy and convenience. The impact of maintenance nebulizer treatment on other relevant clinical outcomes in patients with COPD, especially the progressive decline in lung function and frequency of exacerbations, needs further investigation.

Preliminary investigation of residual-limb fluid volume changes within one day.

The purpose of this research was to investigate rates of residual-limb fluid volume change within one day for people with transtibial limb loss. Rates of fluid volume change during 30 min test sessions of sitting, standing, and walking activities were measured twice a day, once in the morning and once in the afternoon, on 12 regular prosthesis users with the use of bioimpedance analysis. Between test sessions, all subjects consumed food and drink, and subject activity ranged from low to high. The rate of fluid volume change within sessions ranged from -8.5 to 5.9 %/h (median: -2.2%/h). The rate of fluid volume change between sessions ranged from -2.7 to 0.9 %/h (median: -1.0%/h). The between-session rate of fluid volume change correlated highly with afternoon within-session rates of change (r = 0.9) but was not well correlated with morning within-session rates of change (r = 0.8). Subjects with peripheral arterial complications showed greater fluid volume loss rates during test sessions than between sessions. Rate of fluid volume change may be affected by sitting, standing, and walking activities; presence of peripheral arterial complications; being female; time since amputation; and wearing the socket without doffing for extended periods.

Asthma: 2015 and beyond.

Asthma is a multifactorial, chronic inflammatory disease of the airways. The knowledge that asthma is an inflammatory disorder has become a core fundamental in the definition of asthma. Asthma's chief features include a variable degree of air-flow obstruction and bronchial hyper-responsiveness, in addition to the underlying chronic airways inflammation. This underlying chronic airway inflammation substantially contributes to airway hyper-responsiveness, air-flow limitation, respiratory symptoms, and disease chronicity. However, this underlying chronic airway inflammation has implications for the diagnosis, management, and potential prevention of the disease. This review for the respiratory therapy community summarizes these developments as well as providing an update on asthma epidemiology, natural history, cause, and pathogenesis. This paper also provides an overview on appropriate diagnostic and monitoring strategies for asthma, pharmacology, and newer therapies for the future as well as relevant management of acute and ambulatory asthma, and a brief review of educational approaches.

Central fabrication: carved positive assessment.

BACKGROUND: It is estimated that only 24% of practitioners use CAD/CAM regularly. Socket manufacturing error may be a source of the limited use of central fabrication. OBJECTIVES: The purpose of this study was to investigate the differences in shape between computer-manufactured, centrally fabricated carved models and electronic file shapes, to determine if carving was a major source of socket manufacturing error in central fabrication. STUDY DESIGN: Experimental, mechanical assessment. METHODS: Three different trans-tibial model shapes were sent electronically to each of 10 central fabrication facilities for the fabrication of positive foam models. A custom mechanical digitizer and alignment algorithm were used to measure the model shapes and then compare them with the electronic file shapes. RESULTS: Volume differences between the models and the electronic file shapes ranged from -4.2% to 1.0%, and averaged -0.9 (SD = 1.1)%. Mean radial error ranged from -1.2 mm to 0.3 mm and averaged -0.3 (SD = 0.3) mm. Inter-quartile range was between 0.3 mm and 2.7 mm and averaged 0.6 (SD = 0.5) mm. The models were significantly smaller than sockets made from the same electronic file shapes (p < 0.01), but the range of mean radial error and the interquartile range were not significantly different between the models and sockets. CONCLUSIONS: The results demonstrated that there was considerable variability in model quality among central fabricators in the industry, and that carving was not the sole source of socket fabrication error. CLINICAL RELEVANCE: The results provide insight into the severity and nature of carving error by central fabrication facilities. Because we found a wide range of model quality, there is not a consistent fabrication problem across the industry, but instead some central fabrication facilities practice the art of model fabrication better than others.

Effects of elevated vacuum on in-socket residual limb fluid volume: case study results using bioimpedance analysis.

Bioimpedance analysis was used to measure the residual limb fluid volume of seven transtibial amputee subjects using elevated vacuum sockets and nonelevated vacuum sockets. Fluid volume changes were assessed during sessions with the subjects sitting, standing, and walking. In general, fluid volume losses during 3 or 5 min walks and losses over the course of the 30 min test session were less for elevated vacuum than for suction. Numerous variables, including the time of day that data were collected, soft tissue consistency, socket-to-limb size and shape differences, and subject health, may have affected the results and had an equivalent or greater effect on limb fluid volume compared with elevated vacuum. Researchers should well consider these variables in the study design of future investigations on the effects of elevated vacuum on residual limb volume.

Evidence-based clinical practice guideline: inhaled nitric oxide for neonates with acute hypoxic respiratory failure.

Inhaled nitric oxide (INO) is a colorless, odorless gas that is also a potent pulmonary vasodilator. When given via the inhaled route it is a selective pulmonary vasodilator. INO is approved by the United States Food and Drug Administration (FDA) for the treatment of term and near-term neonates with hypoxemic respiratory failure associated with clinical or echocardiographic evidence of pulmonary arterial hypertension. A systematic review of the literature was conducted with the intention of making recommendations related to the clinical use of INO for its FDA-approved indication. Specifically, we wrote these evidence-based clinical practice guidelines to address the following questions: (1) What is the evidence for labeled use? (2) What are the specific indications for INO for neonates with acute hypoxemic respiratory failure? (3) Does the use of INO impact oxygenation, mortality, or utilization of extracorporeal membrane oxygenation (ECMO)? (4) Does INO affect long-term outcomes? (5) Is INO cost-effective therapy? (6) How is the appropriate dosing regimen and dose response to INO established? (7) How is the dose of INO titrated and weaned? (8) Which INO delivery system should be used? (9) How should INO be implemented with different respiratory support devices? (10) What adverse effects of INO should be monitored, and at what frequency? (11) What physiologic parameters should be monitored during INO? (12) Is scavenging of gases necessary to protect the caregivers? Using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) scoring system, 22 recommendations are developed for the use of INO in newborns.

Clinical utility of in-socket residual limb volume change measurement: case study results.

Bioimpedance analysis was used to measure conductive tissue extracellular fluid (ECF) volume changes in the residual limbs of four unilateral transtibial amputee subjects during standing and walking conditions. Results showed that all residual limbs experienced ECF volume decreases during 5 min standing intervals. During 5 min of walking immediately after a standing interval, the residual limbs of healthy subjects increased in ECF volume while those of diseased subjects, one with peripheral vascular disease and another with cardiovascular insufficiency and a high-salt intake, decreased. One subject demonstrated less absolute value ECF volume change during standing and walking at 12 months post-surgical revision compared with at six months. Presentation of bioimpedance data to patients improved compliance to practitioner recommendations and patient understanding. Results were useful towards clinical assessment, patient education, and decision-making about treatment.

Guidelines for asthma management: a review and comparison of 5 current guidelines.

The first clinical practice guidelines for the assessment and management of asthma were published over 20 years ago in New Zealand and Australia. During the same period, British and Scottish groups were collaborating on a United Kingdom version of asthma guidelines. Shortly after the introduction of the New Zealand and Canadian guidelines, the National Heart, Lung, and Blood Institute of the United States National Institutes of Health participated in 2 additional asthma guideline endeavors, which were published in the early 1990s. The National Heart, Lung, and Blood Institute formed the National Asthma Education and Prevention Program to develop asthma guidelines for the United States, and participated with an international task force to develop guidelines for the treatment of asthma in all countries, which resulted in the formation of the Global Initiative for Asthma in the mid-1990s. The asthma guidelines issued by professional societies and other groups prior to the late 1990s were primarily based on consensus or expert opinion in each guideline committee, though those opinions were based on the available studies. The early guidelines played a vital role in bridging the gap between various treatment options and recent discoveries in basic science, and served as the vehicle to implementation into daily clinical practice. Asthma guidelines have been published and revised in dozens of countries around the world and have become reputable directives or "road maps" in asthma diagnosis, treatment, and management for patients of all ages. The guidelines have similar formats. The dissemination and implementation of the early guidelines was inconsistent, and they were criticized for not being evidence-based. As the knowledge of asthma pathophysiology continues to expand, along with basic science research on asthma diagnosis, treatment, and management, as well as education of the asthma patient, it is essential that the asthma guidelines be frequently updated and based on evidence-based-medicine processes.

Asthma disease management and the respiratory therapist.

The role of the respiratory therapist (RT) is expanding with the growing acceptance and use of the disease-management paradigm for managing chronic diseases. RTs are key members of the asthma disease-management team, in acute-care settings, patients' homes, out-patient clinics, emergency departments, and in the community. Utilizing RTs as disease managers allows patients to be treated faster and more appropriately, discharged to home sooner, and decreases hospital admissions. RT are leaders in the emerging field of asthma disease management.

Positive expiratory pressure and oscillatory positive expiratory pressure therapies.

Airway clearance techniques, historically referred to as chest physical therapy, have traditionally consisted of a variety of breathing maneuvers or exercises and manual percussion and postural drainage. The methods and types of airway clearance techniques and devices have rapidly increased in an effort to find a more efficacious strategy that allows for self-therapy, better patient adherence and compliance, and more efficient durations of care. Mechanically applied pressure devices have migrated from European countries over the last several decades to clinical practice in the United States. I conducted a comprehensive MEDLINE search of two such devices: positive expiratory pressure (PEP) and oscillatory positive expiratory pressure (OPEP) and their role in airway clearance strategies. This was followed by a comprehensive search for cross-references in an attempt to identify additional studies. The results of that search are contained and reported in this review. From a methods standpoint, most of the studies of PEP and OPEP for airway clearance are limited by crossover designs and small sample sizes. While PEP and OPEP do not definitively prove superiority to other methods of airway clearance strategies, there is no clear evidence that they are inferior. Ultimately, the correct choice may be an airway clearance strategy that is clinically and cost effective, and is preferred by the patient so that adherence and compliance can be at the very least supported.

Respiratory therapies in the critical care setting. Should every mechanically ventilated patient be monitored with capnography from intubation to extubation?

One of the most important aspects of caring for a critically ill patient is monitoring. Few would disagree that the most essential aspect of monitoring is frequent physical assessments. Complementing the physical examination is continuous monitoring of heart rate, respiratory rate, and blood oxygen saturation measured via pulse-oximetry, which have become the standard of care in intensive care units. Over the past decade one of the most controversial aspects of monitoring critically ill patients has been capnography. Although most clinicians use capnography to confirm endotracheal intubation, few clinicians use continuous capnography in the intensive care unit. This article reviews the medical literature on whether every mechanically ventilated patient should be monitored with capnography from intubation to extubation. There are numerous articles on capnography, but no definitive, randomized study has even attempted to address this specific question. Based on the available literature, it seems reasonable to use continuous capnography, for at least a subset of critically ill patients, to ensure integrity of the endotracheal tube and other ventilatory apparatus. However, at this point definitive data are not yet available to clearly support continuous capnography for optimizing mechanical ventilatory support. We hope that as new data become available, the answer to this capnography question will become clear.