VOL: 97, ISSUE: 07, PAGE NO: 3
Anna Edwards, BSc, RGN, is senior nurse, infection control, Royal Brompton Hospital and Harefield NHS Trust, LondonPatients with both acute and chronic respiratory conditions often require respiratory support, which necessitates the use of nebulised solutions via a variety of nebulising devices. These may facilitate the delivery of drugs, such as antibiotics and bronchodilators, or saline to aid sputum production.
Patients with both acute and chronic respiratory conditions often require respiratory support, which necessitates the use of nebulised solutions via a variety of nebulising devices. These may facilitate the delivery of drugs, such as antibiotics and bronchodilators, or saline to aid sputum production.
There is a current climate of heightened awareness of the need for good infection control practices. Never before, with the numerous Department of Health guidance on decontamination of medical devices (HSC 1999/178, HSC1999/179, HSC 2000/032, DoH 2001), has there been a more high-profile requirement by all health care workers to ensure that all equipment used in direct patient care is regularly decontaminated and does not pose a cross-infection risk.
Levels of decontamination
When formulating hospital policies or local practice guidelines it is essential that an initial risk assessment is undertaken (Ayliffe et al, 1993). The assessment must take into account the use for which the device is to be put, the patient's susceptibility to infection and the level of decontamination required.
Other factors include the nature of contact anticipated with the patient, for instance, with intact skin, with broken skin, with mucous membrane or inside a body cavity or normally sterile body area.
The method and degree of decontamination used on a medical device may be determined by the material from which the device is constructed, the type of microorganisms involved and the level of contact with the patient (Box 1).
Many medical devices, including nebulisers, are designed for single use or single patient use and are then discarded. Information will be clearly identified on the product wrapping (Fig 1 and 2). The Medical Devices Agency (2000) clearly identifies that items marked for single patient use/single use must not be reused under any circumstances. The legal implications for doing so are that the person reprocessing or using a reprocessed item takes full responsibility for its safety and effectiveness.
Design and use of nebulisers
Nebulisers used in the management of patients with respiratory disease may be of varied design and application. The most common and widely used is the 'side stream'(often referred to as an acorn). It may be used for the nebulised delivery of bronchodilatory drugs, such as salbutamol, and in the treatment of patients in more specialist units, such as those for cystic fibrosis, for the administration of nebulised mucolytics, for instance recombinant human deoxyribonuclease.
An antibiotic nebuliser circuit used in the delivery of antibiotics comprises more components and has more complex requirements for decontamination.
The 'bird circuit' may be used to administer intermittent positive pressure ventilation (IPPV), delivery of brochodilators or saline. It is relatively complex in design and includes both expiratory and inspiratory components, thus varying the opportunity for contamination.
Sources of contamination
Patients requiring the use of nebulised agents often have pre-existing respiratory tract infections with a number of pathogens. These may be bacterial (some of which may be antibiotic-resistant), viral or fungal in origin. In particular, gram-negative bacteria such as Pseudomonas aeruginosa are commonly found to contaminate nebulisers. This bacterium may originate either from a patient's own respiratory tract or may be an environmental contaminant. Additionally, any residual fluid left in a nebuliser system will very rapidly become colonised with bacteria from environmental sources. Therefore decontamination processes must include thorough drying before storage and re-use.
Nebuliser decontamination process
In hospital, the use of single use items is usually fairly short in duration and therefore discarded in a short period of time. There is no hard and fast rule regarding the duration of single patient-use nebulisers, but a commonsense approach would be to review the integrity of the equipment and at the earliest signs of stickiness or cracking of the fabric to discard the item.
Patients using equipment at home will have less opportunity for cross-infection than those in hospital. In addition to thorough washing and drying weekly, disinfection in a chlorine-releasing solution (for instance, Milton) is advisable. However, some sidestream nebulisers designed for home use will withstand boiling.
Sidestream nebulisers should never be reprocessed for multiple patient use, as the materials used in their production are not designed to withstand sterilising processes.
Some antibiotic nebuliser circuits are autoclaveable and may be reused for up to one year, after which the manufactures do not guarantee the integrity of the materials used.
All the components (with exception of the mouthpiece, which is disposable), of the bird circuit are autoclaveable. Disposable circuits are now available.
Even when nebuliser components are recyclable a full cost analysis of the process should be undertaken. The time and materials, plus the time out of use in the decontamination process can amount to a greater cost than using disposable alternatives. Most important of all is the need to ensure that there is no opportunity for cross-infection to occur.