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.

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.

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.

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.

Respiratory controversies in the critical care setting. Does airway pressure release ventilation offer important new advantages in mechanical ventilator support?

Airway pressure-release ventilation (APRV) is a mechanical ventilation strategy that is usually time-triggered but can be patient-triggered, pressure-limited, and time-cycled. APRV provides 2 levels of airway pressure (P(high) and P(low)) during 2 time periods (T(high) and T(low)), both set by the clinician. APRV usually involves a long T(high) and a short T(low). APRV uses an active exhalation valve that allows spontaneous breathing during both T(high) and T(low). APRV typically generates a higher mean airway pressure with a lower tidal volume (V(T)) and lower positive end-expiratory pressure than comparable levels of other ventilation strategies, so APRV may provide better alveolar recruitment at a lower end-inflation pressure and therefore (1) decrease the risk of barotrauma and alveolar damage in patients with acute lung injury or acute respiratory distress syndrome (ALI/ARDS), and (2) provide better ventilation-perfusion matching, cardiac filling, and patient comfort than modes that do not allow spontaneous breaths. However, if the patient makes a spontaneous breath during T(high), the V(T) generated could be much larger than the clinician-set target V(T), which could cause the end-inflation transpulmonary pressure and alveolar stretch to be much larger than intended or produced in other ventilation strategies. It is unknown whether a patient's inspiratory effort (and consequent larger V(T)) can damage alveoli in the way that mechanically delivered, positive-pressure breaths can damage alveoli in ALI/ARDS. Other ventilation modes also promote spontaneous breaths, but at overall lower end-inflation transpulmonary pressure. There is a dearth of data on what would be the optimal APRV inspiratory-expiratory ratio, positive end-expiratory pressure, or weaning strategy. The few clinical trials to date indicate that APRV provides adequate gas exchange, but none of the data indicate that APRV confers better clinical outcomes than other ventilation strategies.

Use of heliox in children.

For over 70 years, helium-oxygen mixture (heliox) has been promoted as adjunctive therapy to overcome airflow-obstructive disorders and lesions. In the past 2 decades heliox has gained widespread support in many pediatric emergency departments and intensive care units, in treatment of infants and children with both upper and lower airway obstruction. Because heliox is less dense than air or oxygen, it provides more laminar flow in obstructed airways, and it is purported to reduce work of breathing, respiratory distress, and postextubation stridor. Clinical evidence of the effectiveness of heliox in pediatric patients with airflow obstruction is relatively sparse and appears in the literature primarily as case presentations, case series, and small, uncontrolled studies. This article reviews the rationale and methods for heliox treatment of children with asthma, airway obstruction, bronchiolitis, and croup.

The history and physics of heliox.

Since the discovery of helium in 1868, it has found numerous applications in industry and medicine. Its low density makes helium potentially valuable in respiratory care applications, to reduce work of breathing, improve distribution of ventilation, reduce minute volume requirement, and improve aerosol delivery. This review includes a brief history of the use of heliox (a mixture of helium and oxygen) and addresses issues related to the physics of gas flow when heliox is used. Specifically covered are the Hagen-Poiseuille equation, laminar versus turbulent flow, the Reynolds number, orifice flow, Bernoulli's principle, Graham's law, wave speed, and thermal conductivity.

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.

Clinical pathways in treatment of asthma.

Although the number of medications for the treatment of status asthmaticus is relatively limited, strategies for the management of acute asthma vary widely both among and within institutions. The choice of drugs, doses, timing of administration, duration of treatment, and assessment measures are often left to the discretion of individual physicians; plans are often not formulated on the basis of data showing efficacy, but rather on local availability and the experience and preference of physicians. The elimination of treatment that adds cost but not improved quality of care can be an effective strategy to optimize the care of acute asthma.

Therapeutic gases for neonatal and pediatric respiratory care.

Though oxygen is the most frequently administered gas in respiratory care, the use of other specialty gases has become common practice in neonatal and pediatric intensive care and emergency departments across the United States. This report reviews the literature and evidence regarding 4 such specialty gases: heliox (helium-oxygen mixture), nitric oxide, hypoxic gas (ie, < 21% oxygen), and carbon dioxide. Because heliox is less dense than air or nitrogen, it offers less resistance and turbulence as an inhaled gas and therefore decreases the pressure and work of breathing necessary to ventilate the lung, which assists in the management of conditions that involve airway obstruction. Inhaled nitric oxide is a selective pulmonary vasodilator and during the last 2 decades research has focused on its potential value for treating disorders that involve pulmonary vasoconstriction. Hypoxic gas and carbon dioxide are used in the management of infants suffering hypoplastic left heart syndrome (a congenital heart defect), to equilibrate the pulmonary vascular resistance with the systemic vascular resistance, which is necessary to assure adequate oxygenation and tissue perfusion. Balancing the systemic and pulmonary vascular resistances requires increasing pulmonary vascular resistance and decreasing pulmonary blood flow; hypoxic gas does this by maintaining blood oxygen saturation at around 70%, whereas carbon dioxide does so by increasing P(aCO2) to the range of 45-50 mm Hg.

Accuracy of oxygen analyzers at subatmospheric concentrations used in treatment of hypoplastic left heart syndrome.

INTRODUCTION: The immediate survival of infants with hypoplastic left heart syndrome depends on success in achieving several therapeutic goals: (1) maintain patency of the ductus arteriosus, (2) assure adequate mixing of blood at the atrial level, and (3) establish and maintain a balance between systemic and pulmonary blood flow at or near unity. In accomplishing that final goal, various ventilatory strategies have been used to alter the physiologic modifiers of pulmonary vascular resistance and thus maintain balanced circulation, including ventilation with gas of subatmospheric oxygen concentration. However, no data on this subject have been published in the scientific literature, and commercial oxygen analyzers are specified for use within the range of 0.21 to 1.0 fraction of inspired oxygen (F(IO)(2)), leaving the accuracy of hypoxic gas delivery somewhat uncertain. We evaluated the performance of oxygen analyzers below F(IO)(2) 0.21. METHODS: Two commercially available analyzers were studied: the TED-190 (Teledyne) and the Mini-OX III. Five new analyzers of each model were tested. After a 2-point calibration (F(IO)(2) 1.0 and 0.21), all 5 analyzers of the same model were simultaneously exposed to precision-blended gases at 6 different concentrations of oxygen in nitrogen. Steady state was maintained for at least 2 min at each concentration before readings were recorded. Calibration was verified at F(IO)(2) 0.21 between each level. RESULTS: The mean +/- SD error was 0.0013 +/- 0.0021 for the Mini-OX III analyzers and -0.0004 +/- 0.0009 for the Teledyne analyzers. The upper and lower limits of the 95% confidence interval were 0.39% and -0.13% for the Mini-OX III analyzers and 0.07% and -0.15% for the Teledyne analyzers. The maximum difference between measured and known oxygen concentrations was 1% of full scale. CONCLUSIONS: The Mini-OX III and the Teledyne TED-190 provide accurate and reliable F(IO)(2) readings between 0 and 0.21 that are within the manufacturers' specifications for maximum error. These 2 analyzers are therefore acceptable for use in delivering subambient oxygen concentrations. The Mini-OX III displays oxygen concentration to the nearest 0.1% and may be more appropriate for precise control.

Care of the ventilator circuit and its relation to ventilator-associated pneumonia.

Ventilator circuits should not be changed routinely for infection control purposes. The maximum duration of time that circuits can be used safely is unknown. Evidence is lacking related to ventilator-associated pneumonia (VAP) and issues of heated versus unheated circuits, type of heated humidifier, method for filling the humidifier, and technique for clearing condensate from the ventilator circuit. Although the available evidence suggests a lower VAP rate with passive humidification than with active humidification, other issues related to the use of passive humidifiers (resistance, dead space volume, airway occlusion risk) preclude a recommendation for the general use of passive humidifiers. Passive humidifiers do not need to be changed daily for reasons on infection control or technical performance. They can be safely used for at least 48 hours, and with some patient populations some devices may be able to be used for periods of up to 1 week. The use of closed suction catheters should be considered part of VAP prevention strategy, and they do not need to be changed daily for infection control purposes. The maximum duration of time that closed suction catheters can be used safely is unknown. Clinicians caring for mechanically ventilated patients should be aware of risk factors for VAP (eg, nebulizer therapy, manual ventilation, and patient transport).

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.

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.

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.