Guidance on Mitigating the Risk of Transmitting Respiratory Infections During Nebulization by the COPD Foundation Nebulizer Consortium.

BACKGROUND: Nebulizers are used commonly for inhaled drug delivery. Because they deliver medication through aerosol generation, clarification is needed on what constitutes safe aerosol delivery in infectious respiratory disease settings. The COVID-19 pandemic highlighted the importance of understanding the safety and potential risks of aerosol-generating procedures. However, evidence supporting the increased risk of disease transmission with nebulized treatments is inconclusive, and inconsistent guidelines and differing opinions have left uncertainty regarding their use. Many clinicians opt for alternative devices, but this practice could impact outcomes negatively, especially for patients who may not derive full treatment benefit from handheld inhalers. Therefore, it is prudent to develop strategies that can be used during nebulized treatment to minimize the emission of fugitive aerosols, these comprising bioaerosols exhaled by infected individuals and medical aerosols generated by the device that also may be contaminated. This is particularly relevant for patient care in the context of a highly transmissible virus. RESEARCH QUESTION: How can potential risks of infections during nebulization be mitigated? STUDY DESIGN AND METHODS: The COPD Foundation Nebulizer Consortium (CNC) was formed in 2020 to address uncertainties surrounding administration of nebulized medication. The CNC is an international, multidisciplinary collaboration of patient advocates, pulmonary physicians, critical care physicians, respiratory therapists, clinical scientists, and pharmacists from research centers, medical centers, professional societies, industry, and government agencies. The CNC developed this expert guidance to inform the safe use of nebulized therapies for patients and providers and to answer key questions surrounding medication delivery with nebulizers during pandemics or when exposure to common respiratory pathogens is anticipated. RESULTS: CNC members reviewed literature and guidelines regarding nebulization and developed two sets of guidance statements: one for the health care setting and one for the home environment. INTERPRETATION: Future studies need to explore the risk of disease transmission with fugitive aerosols associated with different nebulizer types in real patient care situations and to evaluate the effectiveness of mitigation strategies.

Review of aerosol delivery in the emergency department.

Aerosol delivery is a vital therapeutic strategy for both adult and pediatric patients presenting to the emergency department with respiratory distress. Aerosolized bronchodilators are frequently used as rescue medications for patients with diagnoses of asthma, chronic obstructive pulmonary disease (COPD), or pneumonia. Historically, emergency department providers utilized jet nebulizers (JNs) for medication delivery, but were challenged by a need for increasingly higher bronchodilator doses to elicit the desired response. Advancements in technology have led to the development of newer specialized aerosol delivery devices and treatment strategies which provide clinicians with improved options for aerosol delivery but may also cause some uncertainty regarding appropriate device selection. Initial investigations comparing these devices presented valuable evidence of in vitro benefit but were unable to demonstrate corresponding improvement in clinical results. More recently there has been an influx of clinical evidence that suggests improved clinical outcomes associated with more efficient aerosol delivery devices such as vibrating mesh nebulizers (VMN) compared to the standard JN device. VMN will likely become an increasingly important tool in emergency department treatment of patients with respiratory distress. Additional controlled studies are needed both to examine the effects of VMN on patient outcomes, as well as to analyze how performance differences between aerosol devices may affect dosing strategies. Future efforts should also focus on applying new evidence in the form of updated consensus guidelines and standardized treatment strategies.

Aerosol Delivery Through Adult High Flow Nasal Cannula With Heliox and Oxygen.

BACKGROUND: Heliox (helium-oxygen mixture) has been shown to reduce turbulence and improve aerosol delivery in a range of clinical settings. We questioned whether heliox as compared with oxygen via high-flow nasal cannula (HFNC) would affect aerosol delivery. We hypothesized that heliox would have a significant effect on aerosol delivery as compared with oxygen with both quiet and distressed breathing patterns. METHODS: A vibrating mesh nebulizer was placed at the inlet of a humidifier via HFNC with small adult cannula distal to the heated-wire circuit with prongs placed into simulated nares with a T-shaped trap and absolute filter connected to a breath simulator set to adult quiet and distressed breathing parameters. Albuterol sulfate (0.083% 2.5 mg/3 mL) was aerosolized with heliox (80:20) and oxygen (100%) at 10, 30, and 50 L/min. Drug eluted from the filter was assayed with UV spectrophotometry (276 nm). Descriptive statistics, Kruskal-Wallis test, and Mann-Whitney U test were used for data analysis. P < .05 was considered statistically significant. RESULTS: Increasing flows with heliox and oxygen significantly decreased percentage inhaled dose (inhaled dose) of aerosol with a quiet breathing pattern (P = .02 and P = .030, respectively). In contrast, with a distressed breathing pattern, inhaled dose at 10 L/min was lower than at 30 and 50 L/min (P = .009 and P = .01, respectively) with both oxygen and heliox (P = .009 and P = .009, respectively). Despite a trend to higher aerosol deposition with heliox versus oxygen, the differences were not significant. CONCLUSIONS: With a distressed breathing pattern, aerosol delivery was greater at 30 and 50 L/min than with a quiet breathing pattern. Trends toward higher inhaled dose with heliox during HFNC were not significant.