Home nebulizer use among patients with cystic fibrosis

Indian Guidelines on Nebulization Therapy

Inhalational therapy, today, happens to be the mainstay of treatment in obstructive airway diseases (OADs), such as asthma, chronic obstructive pulmonary disease (COPD), and is also in the present, used in a variety of other pulmonary and even non-pulmonary disorders. Hand-held inhalation devices may often be difficult to use, particularly for children, elderly, debilitated or distressed patients. Nebulization therapy emerges as a good option in these cases besides being useful in the home care, emergency room and critical care settings. With so many advancements taking place in nebulizer technology; availability of a plethora of drug formulations for its use, and the widening scope of this therapy; medical practitioners, respiratory therapists, and other health care personnel face the challenge of choosing appropriate inhalation devices and drug formulations, besides their rational application and use in different clinical situations. Adequate maintenance of nebulizer equipment including their disinfection and storage are the other relevant issues requiring guidance. Injudicious and improper use of nebulizers and their poor maintenance can sometimes lead to serious health hazards, nosocomial infections, transmission of infection, and other adverse outcomes. Thus, it is imperative to have a proper national guideline on nebulization practices to bridge the knowledge gaps amongst various health care personnel involved in this practice. It will also serve as an educational and scientific resource for healthcare professionals, as well as promote future research by identifying neglected and ignored areas in this field. Such comprehensive guidelines on this subject have not been available in the country and the only available proper international guidelines were released in 1997 which have not been updated for a noticeably long period of over two decades, though many changes and advancements have taken place in this technology in the recent past. Much of nebulization practices in the present may not be evidence-based and even some of these, the way they are currently used, may be ineffective or even harmful. Recognizing the knowledge deficit and paucity of guidelines on the usage of nebulizers in various settings such as inpatient, out-patient, emergency room, critical care, and domiciliary use in India in a wide variety of indications to standardize nebulization practices and to address many other related issues; National College of Chest Physicians (India), commissioned a National task force consisting of eminent experts in the field of Pulmonary Medicine from different backgrounds and different parts of the country to review the available evidence from the medical literature on the scientific principles and clinical practices of nebulization therapy and to formulate evidence-based guidelines on it. The guideline is based on all possible literature that could be explored with the best available evidence and incorporating expert opinions. To support the guideline with high-quality evidence, a systematic search of the electronic databases was performed to identify the relevant studies, position papers, consensus reports, and recommendations published. Rating of the level of the quality of evidence and the strength of recommendation was done using the GRADE system. Six topics were identified, each given to one group of experts comprising of advisors, chairpersons, convenor and members, and such six groups (A-F) were formed and the consensus recommendations of each group was included as a section in the guidelines (Sections I to VI). The topics included were: A. Introduction, basic principles and technical aspects of nebulization, types of equipment, their choice, use, and maintenance B. Nebulization therapy in obstructive airway diseases C. Nebulization therapy in the intensive care unit D. Use of various drugs (other than bronchodilators and inhaled corticosteroids) by nebulized route and miscellaneous uses of nebulization therapy E. Domiciliary/Home/Maintenance nebulization therapy; public & health care workers education, and F. Nebulization therapy in COVID-19 pandemic and in patients of other contagious viral respiratory infections (included later considering the crisis created due to COVID-19 pandemic). Various issues in different sections have been discussed in the form of questions, followed by point-wise evidence statements based on the existing knowledge, and recommendations have been formulated.

Evaluation of Aerosol Therapy during the Escalation of Care in a Model of Adult Cystic Fibrosis

Lung disease is the main cause of morbidity and mortality in cystic fibrosis (CF). CF patients inhale antibiotics regularly as treatment against persistent bacterial infections. The goal of this study was to investigate the effect of clinical intervention on aerosol therapy during the escalation of care using a bench model of adult CF. Droplet size analysis of selected antibiotics was completed in tandem with the delivered aerosol dose (% of total dose) assessments in simulations of various interventions providing oxygen supplementation or ventilatory support. Results highlight the variability of aerosolised dose delivery. In the homecare setting, the vibrating mesh nebuliser (VMN) delivered significantly more than the jet nebuliser (JN) (16.15 ± 0.86% versus 6.51 ± 2.15%). In the hospital setting, using VMN only, significant variability was seen across clinical interventions. In the emergency department, VMN plus mouthpiece (no supplemental oxygen) was seen to deliver (29.02 ± 1.41%) versus low flow nasal therapy (10 L per minute (LPM) oxygen) (1.81 ± 0.47%) and high flow nasal therapy (50 LPM oxygen) (3.36 ± 0.34%). In the ward/intensive care unit, non-invasive ventilation recorded 19.02 ± 0.28%, versus 22.64 ± 1.88% of the dose delivered during invasive mechanical ventilation. These results will have application in the design of intervention-appropriate aerosol therapy strategies and will be of use to researchers developing new therapeutics for application in cystic fibrosis and beyond.

Microbiological contamination of nebulizers used by cystic fibrosis patients: an underestimated problem

Objective:

Home nebulizers are routinely used in the treatment of patients with cystic fibrosis (CF). This study aims to evaluate the contamination of nebulizers used for CF patients, that are chronically colonized by Pseudomonas aeruginosa, and the association of nebulizer contamination with cleaning, decontamination and drying practices.

Methods:

A cross-sectional, observational, multicenter study was conducted in seven CF reference centers in Brazil to obtain data from medical records, structured interviews with patients/caregivers were performed, and nebulizer’s parts (interface and cup) were collected for microbiological culture.

Results:

overall, 77 CF patients were included. The frequency of nebulizer contamination was 71.6%. Candida spp. (52.9%), Stenotrophomonas maltophilia (11.9%), non-mucoid P. aeruginosa (4.8%), Staphylococcus aureus (4.8%) and Burkholderia cepacia complex (2.4%) were the most common isolated pathogens. The frequency of nebulizers’ hygiene was 97.4%, and 70.3% of patients reported cleaning, disinfection and drying the nebulizers. The use of tap water in cleaning method and outdoor drying of the parts significantly increased (9.10 times) the chance of nebulizers’ contamination.

Conclusion:

Despite the high frequency hygiene of the nebulizers reported, the cleaning and disinfection methods used were often inadequate. A significant proportion of nebulizers was contaminated with potentially pathogenic microorganisms for CF patients. These findings support the need to include patients/caregivers in educational programs and / or new strategies for delivering inhaled antibiotics.

Repeated hot water and steam disinfection of Pari LC Plus® nebulizers alter nebulizer output

Currently, cystic fibrosis patients require daily nebulized treatments to achieve optimal lung health. Growth of pathogenic bacteria in patient nebulizers is well known, and disinfection guidelines have been established. In this short communication, we sought to discover what effect, if any, repeated nebulization/disinfection cycles had on nebulizer output. We nebulized saline repeatedly after exposure to boiling water, steam, and alcohol disinfection methods. While alcohol disinfection did not affect nebulizer output, boiling water and steam significantly decreased nebulizer output from baseline, 74.1 ± 5.9% (p = 0.022) and steam 63.6 ± 6.5% (p = 0.0048) after 60 cycles respectively. This decrease in nebulizer output could significantly increase the duration of nebulizer treatment time and negatively impact the burden of care on patients with cystic fibrosis.

Effect that an educational program for cystic fibrosis patients and caregivers has on the contamination of home nebulizers

OBJECTIVE:

To describe the pathogens found in home nebulizers and in respiratory samples of cystic fibrosis (CF) patients, and to evaluate the effect that a standardized instruction regarding cleaning and disinfection of nebulizers has on the frequency of nebulizer contamination.

METHODS:

We included 40 CF patients (22 males), all of whom used the same model of nebulizer. The median patient age was 11.2 ± 3.74 years. We collected samples from the nebulizer mouthpiece and cup, using a sterile swab moistened with sterile saline. Respiratory samples were collected by asking patients to expectorate into a sterile container or with oropharyngeal swabs after cough stimulation. Cultures were performed on selective media, and bacteria were identified by classical biochemical tests. Patients received oral and written instructions regarding the cleaning and disinfection of nebulizers. All determinations were repeated an average of two months later.

RESULTS:

Contamination of the nebulizer (any part) was detected in 23 cases (57.5%). The nebulizer mouthpiece and cup were found to be contaminated in 16 (40.0%) and 19 (47.5%), respectively. After the standardized instruction had been given, there was a significant decrease in the proportion of contaminated nebulizers (43.5%).

CONCLUSIONS:

In our sample of CF patients, nebulizer contamination was common, indicating the need for improvement in patient practices regarding the cleaning and disinfection of their nebulizers. A one-time educational intervention could have a significant positive impact.

Aerosol characteristics of admixture of budesonide inhalation suspension with a beta2-agonist, procaterol

BACKGROUND

Nebulized drugs for asthma treatment are often mixed together in order to simplify inhalation regimens, although not recommended. We therefore evaluated aerosol characteristics and physicochemical stability of the admixture of an inhaled corticosteroid suspension with a beta2-agonist solution.

METHODS

An 8-stage cascade impactor was used to measure the particle size distribution of admixture of Pulmicort® Respules® (budesonide, 0.5mg/2mL) with Meptin® Inhalation Solution Unit (procaterol hydrochloride, 30μg/0.3mL) from a jet nebulizer, PARI LC Plus®. Concentration of each drug was assayed with high-pressure liquid chromatography. Physicochemical compatibility was also assessed up to 24 hours after mixing.

RESULTS

With regard to budesonide, impactor parameters such as mass median aerodynamic diameter (MMAD) and respirable mass (RM) were comparable between admixtures and single-drug preparations (2.92 ± 0.03 vs 2.99 ± 0.14μm, 146.8 ± 2.9 vs 147.6 ± 8.2μg, respectively). On the other hand, delivery rates of procaterol increased when admixed with budesonide suspension, resulting in significantly higher RM (15.1 ± 0.8 vs 10.2 ± 0.5μg, p < 0.01). Variations from initial concentration in the percentages of drug remaining at any time point were less than 10%, and there were no appreciable changes in pH of the admixtures for up to 24 hours.

CONCLUSIONS

There is a possibility that admixture might influence of aerodynamic characteristics of procaterol, but not budesonide. In vivo data will be needed for the clinical implications of our findings.

[Inhalation therapy: provocation tests, infectious risks, acute bronchiolitis and ENT diseases. GAT aerosolstorming, Paris 2011]

Communications from the 2011 meeting of the GAT are reported in this second article on the practical management of bronchial provocation tests and infectious risks associated with the use of nebulization. Recent advances on the role of nebulized hypertonic saline in the treatment of acute bronchiolitis in infants and of the nebulization in sinusal diseases are also reported.

Challenges with current inhaled treatments for chronic Pseudomonas aeruginosa infection in patients with cystic fibrosis

BACKGROUND

Pseudomonas aeruginosa (Pa) is the predominant pathogen infecting the airways of patients with cystic fibrosis (CF). Initial colonization is usually transient and associated with non-mucoid strains, which can be eradicated if identified early. This strategy can prevent, or at least delay, chronic Pa infection, which eventually develops in the majority of patients by their late teens or early adulthood. This article discusses the management and latest treatment developments of Pa lung infection in patients with CF, with a focus on nebulized antibiotic therapy.

METHODS

PubMed was searched to identify English language articles published up until August 2011 using combinations of the following key words: 'antibiotics', 'chronic', 'cystic fibrosis', 'eradication', 'exacerbations', 'guidelines', 'inhaled', 'intravenous', 'lung infection', 'burden', 'adherence', 'patient segregation', 'pseudomonas aeruginosa' and 'resistance'.

FINDINGS

Antibiotics form a central part of the treatment regimens for chronic Pa lung infection. Current treatment guidelines recommend that patients with chronic pulmonary infection with Pa should receive long-term inhaled anti-pseudomonal therapy to preserve lung function, and to reduce the frequency of pulmonary exacerbations and hospital admissions. While antibiotic resistance seems to increase with frequent antibiotic use, this does not appear to impact on clinical outcome. Negative aspects of therapy include the time needed for drug administration and subsequent cleaning of the equipment. These factors cause a significant treatment burden and impact on adherence. The availability of more convenient formulations and delivery vehicles for anti-pseudomonal antibiotics may help overcome some of these challenges.

CONCLUSIONS

Current challenges in the management of CF patients with chronic Pa lung infection are numerous. The availability of novel anti-pseudomonal antibiotic formulations/devices is anticipated to improve treatment adherence in patients with CF, and could improve clinical outcomes. Thus, there is hope for improved survival in individuals with CF suffering from chronic pulmonary infection with Pa.

Nebulizers in cystic fibrosis: a source of bacterial contamination in cystic fibrosis patients?

OBJECTIVE

To determine whether nebulizers are a source of microbial contamination in patients with cystic fibrosis, as well as whether the technique and frequency of disinfection of these devices is appropriate.

METHODS

This was a cross-sectional, uncontrolled observational study. Samples were collected from 28 patients with cystic fibrosis. Samples were collected at the homes of the patients, who were not previously informed of the purpose of the visit. Three samples were collected from each patient: one from the nebulizer chamber, one from the mask/mouthpiece, and one from the patient (oropharyngeal swab /sputum). The samples were properly stored and taken for analyses. The patients, their parents, or their legal guardians completed a questionnaire regarding nebulizer cleaning and disinfecting methods.

RESULTS

We collected 84 samples from the 28 patients. Of those 28 patients, 15 (53.5%) were male. The median age of the patients was 11 years (range, 1-27 years). Of the 28 patients, 15 presented with positive oropharyngeal swab /sputum sample cultures. The most common bacterial isolates were Staphylococcus aureus (in 8 patients) and Pseudomonas aeruginosa (in 4 patients). Although the samples obtained from the nebulizers presented with various pathogens in culture, no specific species predominated. In 27 cases (96.7%), there were no associations between the samples obtained from the nebulizers and those obtained from the patients in terms of the results of the cultures. Cleaning and disinfection of nebulizers were inappropriate in 22 cases (78.6%).

CONCLUSIONS

In this sample of patients, despite the inappropriate disinfection techniques, nebulizers were not found to be a source of microbial contamination.

Toward modern inhalational bacteriophage therapy: nebulization of bacteriophages of Burkholderia cepacia complex

Antibiotic-resistant bacterial infections have renewed interest in finding substitute methods of treatment. The purpose of the present in vitro study was to investigate the possibility of respiratory delivery of a Burkholderia cepacia complex (BCC) bacteriophage by nebulized aerosol administration. Bacteriophages in isotonic saline were aerosolized with Pari LC star and eFlow nebulizers, at titers with mean value (standard deviation) of 2.15 x 10(8) (1.63 x 10(8)) plaque-forming unit (PFU)/mL in 2.5-mL nebulizer fills. The breathing pattern of an adult was simulated using a pulmonary waveform generator. During breath simulation, the size distributions of the nebulized aerosol were measured using phase doppler anemometry (PDA). Efficiency of nebulizer delivery was subsequently determined by collection of aerosol on low resistance filters and measurement of bacteriophage titers. These filter titers were used as input data to a mathematical lung deposition model to predict regional deposition of bacteriophages in the lung and initial bacteriophage titers in the liquid surface layer of each conducting airway generation. The results suggest that BCC bacteriophages can be nebulized successfully within a reasonable delivery time and predicted titers in the lung indicate that this method may hold potential for treatment of bacterial lung infections common among cystic fibrosis patients.

Compatibility of arformoterol tartrate inhalation solution with three nebulized drugs

OBJECTIVE

Arformoterol tartrate inhalation solution (15 microg/2 mL) is approved for the twice-daily, long-term maintenance treatment of bronchoconstriction in patients with chronic obstructive pulmonary diseases (COPD). This study assessed the chemical and physical compatibility of arformoterol (15 microg/2 mL) with ipratropium bromide (0.5 mg/2.5 mL), acetylcysteine (800 mg/4 mL), and budesonide (0.25 mg/2 mL and 0.5 mg/2 mL).

METHODS

Immediately (T(0)) and 30 min (T(30)) after preparation, the admixtures were tested by visual inspection, pH measurement, and HPLC assay of each active component.

RESULTS

For all admixtures, no visible signs of change were observed. The pH of all admixtures at T(0) ranged from 4.82 to 6.40, which was within the range of individual drugs. For all admixtures, no unacceptable changes (less than 1% or 0.1 pH unit) in the pH values were observed within 30 min compared with the initial pH values in the admixtures, which met acceptance criteria of not more than (NMT) 10.0%. At both T(0) and T(30), the assay of each active component in all admixtures ranged from 98.3% to 101.4% compared to the assay in control samples, which met acceptance criteria of NMT 10.0%. In addition, no changes (less than 8%) in the assay of each active component at T(30) were observed compared to the initial assay values, which met acceptance criteria of NMT 10.0%. This study did not evaluate the clinical efficacy or safety of mixing arformoterol in patients. Nor did the study assess the aerosol characteristics of these admixtures or any potential changes in drug output.

CONCLUSION

The results demonstrated that arformoterol was chemically and physically compatible with commercially available nebulized formulations of ipratropium bromide, acetylcysteine, and budesonide.

Microbial contamination of nebulizers in the home treatment of cystic fibrosis

BACKGROUND

Home nebulizers are in widespread use in cystic fibrosis (CF) and other chronic pulmonary diseases. Bacterial contamination may be a source of respiratory tract colonization.

OBJECTIVES

To investigate microbial contamination of home nebulizers in CF patients, compare with sputum cultures and relate to cleaning practices.

METHODS

A total of 29 home nebulizers of CF patients were cultured. Families were interviewed regarding cleaning routines and patients had sputum cultures for bacteria and fungi.

RESULTS

In total, 19/29 (65%) nebulizers were contaminated: 18 reservoir cups, 14 mouthpieces and five filters. Pseudomonas spp. were isolated from 10 nebulizers (35%) and all 10 had Pseudomonas aeruginosa airway infection although without genetic typing we could not be sure this was the same bacteria as that from their nebulizer unit. An additional 7/29 had Pseudomonas aeruginosa airway infection without a contaminated nebulizer (P=0.001). No nebulizers were contaminated with Aspergillus. Only 4/19 contaminated nebulizers (22%) had been cleaned after every use, compared with seven of the 10 (70%) uncontaminated nebulizers (P=0.017). Only 7/19 patients with contaminated nebulizers (37%) and 5/10 with clean nebulizers (50%) recalled receiving cleaning instructions (not significant).

CONCLUSIONS

Home nebulizers are frequently contaminated, particularly when cleaning instructions are inadequate, and may be a source of airway infection or reinfection especially following contamination from a patient chronically colonized with P. aeruginosa. Simple oral and written cleaning instructions should be offered.

Effect of dry powder inhaler resistance on the inspiratory flow rates and volumes of cystic fibrosis patients of six years and older

Several inhaled drugs for use by cystic fibrosis (CF) patients are formulated for nebulizer use only. This therapy is time consuming and includes the risk of contamination of the nebulizers. Dry powder inhalers (DPI) can be an attractive alternative for CF drugs. Inhaled flow rate and volume, and the device resistance are important determinants for optimal dispersion of drug from a DPI. It is important to understand how these variables interact in the CF population in order to properly design a new DPI formulation targeted for these patients. The objective of this study was to assess the inspiratory variables of a representative population of CF subjects 6 years and older with varying degrees of lung disease while inhaling through resistances that simulate DPI devices. Ninety-six stable CF patients were enrolled, ages 6-54 years, FEV(1) 19-126% predicted. Subjects inhaled forcefully through four different resistances (0.019, 0.024, 0.038, and 0.048 kP(0.5)/LPM, respectively), while inspiratory time (IT(DPI)), peak inspiratory flow (PIF(DPI)), and volumes (V(DPI)) were measured. For any resistance, inspired V(DPI) increased with the older age groups; PIF(DPI) was similar between adults and adolescents but lower in the children. Subjects with lower FEV(1) had lower V(DPI) and PIF(DPI). As resistance increased, PIF(DPI) decreased, IT(DPI) increased, with no significant change in V(DPI). At the lowest resistance mean PIF(DPI) was 105 LPM (range 45-163) for all patients; 112 LPM (range 75-163) in adults; and 89 LPM (45-126) in children. Mean inspired V(DPI) was 1.75 L for all patients; 2.2 L (0.8-3.7) in adults; and 1.2 L (0.5-1.8) in children. At the lowest resistance a minimal flow rate of 30, 45, and 60 LPM was attained in 100%, 99%, and 96% of all patients. Volumes of 1.0, 1.5, and 2.0 L were attained by 85%, 57%, and 30% of the patients. At the highest resistance mean PIF(DPI) was 52 LPM (range 26-70) for all patients; 55 LPM (40-70) in adults; and 47 LPM (26-62) in children. Mean inspired V(DPI) was 1.5 L in all patients; 1.9 L (0.9-3.5) in adults and 1.1 L (0.5-2.3) in children. At the highest resistance, a minimal flow rate of 30, 45, and 60 LPM was attained in 99%, 80%, and 22% of all patients. Volumes of 1, 1.5, and 2 L were attained in 84%, 45%, and 23% of the patients. We defined ranges for inspiratory variables in a diverse CF population for a range of device resistances that bracket those of current DPIs. The recorded inspiratory patterns can be used on the bench to design and test new dry powder formulations and devices to target the largest proportion of the CF population.

Mucoviscidose : le kinésithérapeute face au risque infectieux

INTRODUCTION

Respiratory infections play a deleterious role in the progression of patients suffering from cystic fibrosis. Cross infections and epidemics have been documented in these patients, justifying a rigorous prevention regime.

BACKGROUND

This prevention regime concerns all health workers and rests on various recommendations. Segregation of patients and hand hygiene are important factors. Respiratory equipment and, more specifically, nebulisers represent a potential source of bacterial contamination requiring special attention. In the same perspective the risks related to the health care environment, particularly the lung function laboratory, should not be ignored. The modalities of prevention sometimes have a significant psychological impact that may often be reduced by careful explanation.

CONCLUSIONS

In view of the time spent in contact with these patients the physiotherapists are naturally involved in this prevention regime which is an integral part of their treatment.

Nebulized Drug Admixtures: Effect on Aerosol Characteristics and Albuterol Output

Although not recommended, co-administration of drugs separately prescribed for nebulization is done in real life. The impact of this practice on drug output and aerosol characteristics is poorly understood. We studied the effect of drug admixtures (DA) on aerosol characteristics and drug output of nebulized albuterol delivered by a continuous output (CONT) and a breath enhanced nebulizer (BEN). Albuterol was nebulized alone (ALB) and combined with cromolyn sodium (A+CRO), ipratropium bromide (A+IB), tobramycin (A+TOB), flunisolide (A+FLU), and n-acetylcysteine (A+NAC). A BEN (PARI LC Plus) and a CONT (Hudson T UP-DRAFT II) were tested at 8 liters per minute (Lpm) for 2 and 5 min, respectively. Albuterol output and aerosol characteristics were determined by impaction and chemical analysis. Mass median aerodynamic diameter (MMAD; microm) A+CRO reduced MMAD from 2.57 (ALB) to 1.29 with CONT. A+FLU increased MMAD from 2.71 (ALB) to 3.40 with BEN. Geometric standard deviation (GSD) A+CRO increased GSD from 2.66 (ALB) to 3.36 with CONT. GSD was 2.33 for ALB and was not changed by DA with BEN. BEN generated a smaller and less heterodisperse aerosol than CONT. Respirable fraction (RF%) was 74% for ALB and was not changed by DA with CON. A+TOB and A+FLU decreased RF% from 75%, to 70% and 67% (respectively) with BEN. Respirable mass (RM; microg) for ALB was 935 and was not changed by DA with CONT. A+IB and A+FLU increased RM from 917 (ALB) to 1172 and 1240, respectively, with BEN. Co-nebulization of albuterol with other drugs can affect its output and aerosol characteristics. In vivo data is needed to asses the clinical implications of our findings.

Aerosolised antibiotics: a critical appraisal of their use

Aerosolised antimicrobial agents have been used in clinical practice since the 1950s. The main advantage of this route of administration is the targeted drug delivery to the site of infection in the lung. Exploitation of this targeted delivery can yield high concentrations at the site of infection/colonisation while minimising systemic toxicities. It is important to note that the ability of a drug to reach the target area in the lung effectively is dependent on a number of variables, including the nebuliser, patient technique, host anatomy and disease-specific factors. The most convincing data to support the use of aerosolised antimicrobials has been generated with tobramycin solution for inhalation (TOBI, Chiron Corp.) for maintenance treatment in patients with cystic fibrosis. In addition to cystic fibrosis, the use of aerosolised antimicrobials has also been studied for the treatment or prevention of a number of additional disease states including non-cystic fibrosis bronchiectasis, ventilator-associated pneumonia and prophylaxis against pulmonary fungal infections. Key studies evaluating the benefits and shortcomings of aerosolised antimicrobial agents in these areas are reviewed. Although the theory behind aerosolised administration of antibiotics seems to be sound, there are limited data available to support the routine use of this modality. Owing to the gaps still existing in our knowledge base regarding the routine use of aerosolised antibiotics, caution should be exercised when attempting to administer antimicrobials via this route in situations falling outside clearly established indications such as the treatment of patients with cystic fibrosis or Pneumocystis pneumonia.

In vitro evaluation of efficacy of 5 methods of disinfection on mouthpieces and facemasks contaminated by strains of cystic fibrosis patients

INTRODUCTION

Home-nebulizers are a potential source of bacterial infection of the respiratory tract in patients suffering from cystic fibrosis. Recommendations for disinfecting this equipment are often arbitrary and sometimes contradictory.

OBJECTIVE

To assess in vitro the effectiveness of 5 methods of disinfecting this equipment.

METHODS

160 mouthpieces and 160 masks of nebulizers were artificially and massively contaminated with 16 strains of germs found in patients with cystic fibrosis (Staphylococcus aureus, Pseudomonas aeruginosa, Stenotrophomonas maltophilia, Burkholderia cenocepacia, Alcaligenes xylosoxydans). A controlled comparison was carried out of the five methods of disinfection (hypochlorite solution (0.02% active chlorine), acetic acid 3.5%, Hexanios 0.5%, washing-up detergent 0.5% and a dishwasher), tested with and without drying. Standardised bacteriological sampling took place 4 h after disinfecting.

RESULTS

Following treatment, the disappearance of the germ was recorded in 84.1% of cases, and effective disinfecting (reduction>5 log CFU/mL) in another 10.6%. Disinfection failure (5.3%) was found almost only in the case of acetic acid against Staphylococcus aureus.

CONCLUSION

With the exception of acetic acid, the methods of disinfecting tested in this study appeared to be effective against common bacterial pathogens in cystic fibrosis.

Bacterial contamination of inhalation chambers: results of a pilot study

Spacers are used in the treatment of children with asthma. It is advised to clean the spacers regularly. However, cleaning can influence drug delivery. One obvious reason to clean a spacer is prevention of bacterial contamination. Whether spacers are contaminated or not is unknown. We cultured spacers, brought in by children with asthma or recurrent wheeze who visited our outpatient clinic during a 4-month period. The spacers of 64 children were studied, and 24 (38%) were contaminated; most often (13 cases), Bacillus species were found. Only one spacer grew a potential pathogenic bacterium (Pseudomonas aeruginosa). No correlation with type of inhaler, duration of usage, drug, or visual aspect was found. Spacers, cleaned according to national guidelines, were not less contaminated. Bacterial contamination of spacers is frequent, but the bacteria cultured are not pathogenic. Intensive cleaning of spacers does not influence the level of contamination with environmental bacteria.

Early intervention and prevention of lung disease in cystic fibrosis: a European consensus

In patients with cystic fibrosis (CF), early intervention and prevention of lung disease is of paramount importance. Principles to achieve this aim include early diagnosis of CF, regular monitoring of the clinical status, various hygienic measures to prevent infection and cross-infection, early use of antibiotic courses in patients with recurrent or continuous bacterial colonisation and appropriate use of chest physiotherapy.

Infection control recommendations for patients with cystic fibrosis: microbiology, important pathogens, and infection control practices to prevent patient-to-patient transmission

Infection Control Recommendations for Patients With Cystic Fibrosis: Microbiology, Important Pathogens, and Infection Control Practices to Prevent Patient-to-Patient Transmissionupdates, expands, and replaces the consensus statement,Microbiology and Infectious Disease in Cystic Fibrosispublished in 1994. This consensus document presents background data and evidence-based recommendations for practices that are intended to decrease the risk of transmission of respiratory pathogens among CF patients from contaminated respiratory therapy equipment or the contaminated environment and thereby reduce the burden of respiratory illness. Included are recommendations applicable in the acute care hospital, ambulatory, home care, and selected non-healthcare settings. The target audience includes all healthcare workers who provide care to CF patients. Antimicrobial management is beyond the scope of this document.

Aerosol characterization of nebulized intranasal glucocorticoid formulations

Inhaled glucocorticoids (GCs) are the mainstay of long-term therapy for asthma. The lack of suitable preparations in the United States has induced clinicians to use intranasal (IN) GC formulations as "nebulizer suspensions" for off-label therapy. However, no data are available regarding aerosol production and characteristics. The aim of this study was to characterize drug outputs and aerodynamic profiles of four nebulized IN GC formulations with further analysis of flunisolide (Flu), and to test the influence of different delivery system/formulation combinations. The aerodynamic profiles and drug outputs were determined by impaction and chemical analysis. The solution output was determined by the gravimetric technique. Triamcinole acetonide (TAA), fluticasone propionate (Flut), beclomethasone dipropionate (Bec), and Flu (550, 500, 840, and 250 microg, respectively) diluted to 4 mL with saline solution were tested with the Sidestream (SID) and Aero-Tech II (AT2) nebulizers. Subsequently, Flu was tested with four additional nebulizers (Pari LC + [PARI] Acorn II, Hudson T Up-draft II, and Raindrop). All the aerosols were heterodisperse and had a particle size range optimal for peripheral airway deposition (1.85 to 3.67 microm). Flu had the highest drug output in the respirable range (22.8 and 20.3 microg/min with the AT and SID, respectively). Flu was 5-11 times more efficiently nebulized than the other formulations tested. No differences were detected in the solution outputs (0.25 to 0.3 mL/min). In subsequent testing of Flu, the PARI, AT, and SID showed the best performances. The LC+ achieved the highest drug and solution output (27.4 microg/min and 0.89 mL/min, respectively). In conclusion, Flu showed the best aerosol performance characteristics. These data do not endorse the off-label utilization of nebulized IN GC, but underscores the importance of in vitro testing before selecting any formulation/nebulizer combinations for clinical use.

Technical report: precautions regarding the use of aerosolized antibiotics. Committee on Infectious Diseases and Committee on Drugs

In 1998, the Food and Drug Administration (FDA) approved the licensure of tobramycin solution for inhalation (TOBI). Although a number of additional antibiotics, including other aminoglycosides, beta-lactams, antibiotics in the polymyxin class, and vancomycin, have been administered as aerosols for many years, none are approved by the FDA for administration by inhalation. TOBI was approved by the FDA for the maintenance therapy of patients 6 years or older with cystic fibrosis (CF) who have between 25% and 75% of predicted forced expiratory volume in 1 second (FEV(1)), are colonized with Pseudomonas aeruginosa, and are able to comply with the prescribed medical regimen. TOBI was not approved for the therapy of acute pulmonary exacerbations in patients with CF nor was it approved for use in patients without CF. Currently, no other antibiotics are approved for administration by inhalation to patients with or without CF. The purpose of this statement is to briefly summarize the data that supported approval for licensure of TOBI and to provide recommendations for its safe use. The pharmacokinetics of inhaled aminoglycosides and problems associated with aerosolized antibiotic treatment, including environmental contamination, selection of resistant microbes, and airway exposure to excipients in intravenous formulations, will be discussed.

Inhaled tobramycin and bronchial hyperactivity in cystic fibrosis

The use of inhaled tobramycin for prophylaxis and treatment of respiratory symptoms in cystic fibrosis (CF) is now widespread. There have been concerns that inhaling the intravenous (I.V.) formulation of tobramycin causes bronchoconstriction. Previous studies using this formulation have either not specified the nebulizing equipment, or studied older, more severely affected patients. This study investigated the incidence of bronchoconstriction with tobramycin inhalation in children with mild to moderate CF. We studied 26 patients between the ages of 7 and 17 years, with mild to moderate CF (20 female). Prior to being placed on prolonged inhaled tobramycin therapy, they underwent a "tobramycin challenge." FEV(1) was measured pre and post challenge. For the test, standard I.V. solution (80 mg/2 mL) diluted with 2 mL of normal saline was nebulized, using the Hudson (Temecula, CA) RCI Updraft II nebulizer. The nebulization lasted 2 min. There was a 3-min "quiet period," following which FEV(1) was measured. A decrease in FEV(1) by at least 10% post-tobramycin inhalation was considered to be a positive test. Results were analyzed using the Pearson Chi-square test. Five of 26 (19%) had a positive reaction to tobramycin. Sixteen of 26 (61.5%) were using salbutamol on a daily basis at the time of testing but not for 48 hr before the challenge, and 16 of 26 (61.5%) had a pre-tobramycin FEV(1) of < or =80%. Neither an FEV(1) of <80% (P = 0.93) nor regular use of salbutamol (P = 0. 34) were associated with a positive tobramycin challenge. This study suggests that, while bronchoconstriction does occur, many patients do not exhibit bronchoconstriction in response to the standard I.V. preparation and, as prior work suggests, this may be reduced further by pretreatment with salbutamol.

Lung delivery of aerosolized dextran

The ability of nebulizers to deliver dextran (nominal molecular mass, 4,000 g/mol) to the lung as an inhaled aerosol is evaluated by in vitro experimental methods and mathematical models. Dextran in isotonic saline was aerosolized by four nebulizer types (Pari LC STAR, Hudson T-Updraft II, Acorn II, and Sonix 2000) at dextran concentrations </= 400 mg/ml and with 2.5- and 4-ml volume fills. Aerosols inhaled during breath simulation were characterized by in-line phase Doppler anemometry, filter collection, osmometry, and gravimetry. Mathematical models were used to estimate amounts of the characterized aerosols depositing in the different regions of lung models, and mathematical models of mucous thickness were then developed to estimate initial concentrations of the depositing dextran in the mucus of each conducting airway generation. Models of three subjects (4 yr old, 8 yr old, and adult) were used. The high viscosity of the dextran solutions tested (up to seven times that of water) negatively impacts nebulization, and results in poor performance with most delivery systems tested. Our results suggest that airway mucosal dextran concentrations associated with efficacy in previous animal and in vitro models are achievable with reasonable delivery times (</= 12 min) with only one of the delivery systems/formulations tested: the Pari LC STAR nebulizer, using a 2. 5-ml volume fill and a dextran concentration of 200 mg/ml.

Aerosol therapy for asthma

Inhaled drugs play an important role in asthma management. The correct use of an appropriate delivery device is necessary to achieve the desired therapeutic effects of the drug. Currently, chlorofluorocarbon-propelled metered-dose inhalers, with or without spacers, are the most popular aerosol delivery devices. With the planned phase out of the chlorofluorocarbon metered-dose inhalers, the use of other delivery devices is being emphasized. To achieve optimal therapeutic effects, the drug and the delivery device should be considered a "couple". Aerosol delivery devices should provide an adequate "drug dose to the lung", be cost effective, simple to operate, minimize oropharyngeal deposition and systemic side effects, and match the patient's requirements. A new generation of aerosol delivery devices, incorporating the latest advances in aerosol technology, is likely to fulfill many of the goals mentioned above.

Effects of repetitive use and cleaning techniques of disposable jet nebulizers on aerosol generation

STUDY OBJECTIVE

Patients with cystic fibrosis use disposable jet nebulizers for the self-administration of antibiotics, DNase, and bronchodilators several times per day. Most patients elect to reuse their disposable nebulizers. The purpose of this study was to determine if significant changes in particle size distribution or output (mL/min) occurred with reuse.

DESIGN

In vitro studies were performed using four disposable models and one durable jet nebulizer for up to 100 runs; measurements of particle size and output were obtained at 10 run intervals, using saline solution alone, tobramycin, gentamicin, or a mixture of albuterol and cromolyn. Particle size determinations were made with a laser diffraction analyzer.

RESULTS

There was no significant difference between the baseline performance of the four disposable models and the durable Pari LC, when measuring particle size distribution of the aerosol; the Pari LC had an output rate two to three times higher than the four disposable models. For each of the four solutes tested, there was no clinically significant change in performance for up to 100 cycles, when the nebulizers were properly cleaned between uses. Unwashed units containing tobramycin started to fail by 40 runs.

CONCLUSIONS

When properly maintained, there was no trend of deterioration of performance with repeated use of disposable nebulizers. Microbial contamination was not addressed in this study and must be considered prior to recommendations for the reuse of disposable nebulizers.