Mike: Hello, I'm Mike Clarke, podcast editor for the Cochrane Library. There are more than 100 Cochrane Reviews relevant to the care of people with cystic fibrosis and an update for the one looking at the effects of nebulisers was published in November 2023. Here's the new lead author, Gemma Stanford, from the Royal Brompton Hospital in London UK to tell us about it.

Gemma: Cystic fibrosis is a genetic condition which causes sticky mucus to build up in the lungs. This is hard to get rid of and can cause infection if it builds up. I updated this review, with my physiotherapy colleagues Lisa Morrison and Catherine Brown to provide the latest evidence on different nebuliser systems for giving inhaled medications to people with the condition.
Inhaled medications, some taken through nebuliser systems, target a patient's lungs to control symptoms and disease progression. Nebuliser systems change a liquid medication into a mist, so that it can be breathed in, and new systems are developing quickly and becoming more complex. They are also becoming “intelligent” in order to fit better with a person's breathing, to switch off independently and to record data in more detail than ever before.
As physiotherapists, we are often involved in suggesting the equipment that patients might use for different medications. Updating this review highlights for us and others what systems are available and the evidence base for these.
We wanted to know how well the different nebuliser systems deliver different inhaled medications and how they affect people with cystic fibrosis. We wanted to look at treatment burden, adherence to treatment, quality of life and what (if any) side effects arise from using them.
We looked at five different nebuliser systems. These are: 

• Conventional systems, which push out a constant mist of medication.
• Adaptive aerosol delivery systems, which are like conventional systems but also monitor breathing and only deliver the medication while the person is breathing in.
• Vibrating mesh technology systems, which move the liquid medication through a metal mesh to generate a mist with similar‐sized droplets which is delivered constantly.
• Adaptive aerosol delivery systems that combine the adaptive features and vibrating mesh technology.
• And ultrasonic systems which use a crystal to vibrate the liquid medication at a high frequency and turn it into a mist which is delivered constantly.

Different types of nebuliser systems are used with different drugs, with some drugs only being suitable for use with specific systems. With this in mind, we compared nebuliser systems for delivering two antibiotics, tobramycin and colistin; Dornase alfa and hypertonic saline, which help to loosen sputum (called mucoactives) and other aerosolised medications which included drugs such as salbutamol which works to open up the airways.
For each medication, we compared conventional systems with any other identified nebuliser delivery system or with another type of conventional system. We considered “conventional systems” to be a compressor combined with a jet nebuliser handset, including open‐vent jet systems and breath‐assisted open‐vent systems. We also included comparisons of breathing modes with the same nebuliser system. In this way, we tried to make the review as comprehensive as possible.
In total, we included 33 studies which had studied nearly 2300 adults and children with CF. But, data were not available for all of the comparisons.
In terms of the results, we found that conventional systems with faster air flows and smaller medication droplets decrease treatment time and deliver more medication into the lung than other conventional systems. However, nebulisers that use newer technologies, such as an adaptive aerosol delivery system or vibrating mesh technology, deliver the medication faster and may deliver more of the medication into the lung than conventional systems. These newer systems appear safe when used with the correct amount of medication, and the amount of medication needed may be different to that used in a conventional system. Some studies also suggested that people with cystic fibrosis may prefer these newer systems and may take more of their medication when using them.
However, there are still important gaps in our knowledge. More research is needed into what dose of medication is needed for the different systems, which medications suit which technologies best and how these newer nebuliser technologies affect quality of life, burden of treatment, additional treatment needed (such as oral or intravenous antibiotics) and treatment costs.
To sum up, the key take-away messages are that the newer nebuliser technologies do seem to have advantages over conventional systems in terms of deposition of the drug to the lung. This is important when prescribing a medication, but also brings advantages in treatment time which can hugely affect treatment burden for patients and improve adherence to the medication.  Nebulised therapies can be very time-consuming for people to take, and awareness that a quicker compressor system could be available to safely take a medication is important for clinicians. However, it is also important to acknowledge that at present, not all medications are suitable for all compressor systems.

Mike: Thanks Gemma. Listeners who would like to learn more about these benefits and limitations can find the review online. A visit to Cochrane Library dot com and a search for 'nebuliser systems for cystic fibrosis' will find it.