Aerosol administration during nasal CPAP in newborns can be optimized.
- Jan Mazela
- Respiratory care
papers assessing drug delivery systems used to administer aerosols to infants and children. 2 The publication of these papers is notable for two reasons. The first, and most striking, is that they use radiolabelled aerosols and gamma scintigraphy to answer the questions posed. While there are now many such studies published in a variety of respiratory and paediatric journals, this journal has previously, on the basis of reviewers’ comments, declined to publish such papers on the grounds that it would appear to be “unethical” to administer radioactivity to children for such research purposes. In addition their publication occurs at a time when most journals have, quite reasonably, become increasingly resistant to publication of studies purporting to assess inhaler systems in vitro or in vivo which do not include evidence of clinical relevance. In most respects the ethical issues surrounding the use of radiolabelled deposition studies are no different to those involving children in other types of research. Issues surrounding the need on the one hand to act in an individual child’s best interest while on the other hand protecting children from the potential harmful effects of using inadequately tested drugs, and the difficulties of obtaining truly informed consent in young children involved in pharmaceutical trials have been discussed frequently in recent years. It is recognised that such studies are vital if therapeutic advances are to be achieved, but that there are potential risks to the child participating in the study, particularly when a new chemical entity (NCE) is being assessed. In order to justify any such risk, studies must be well designed and powered in order to provide adequate answers to questions regarding safety and efficacy. In addition the potential benefits of undertaking a study must justify any potential risk. Radiolabelled deposition studies differ from a clinical safety/efficacy study of a NCE in two respects. Firstly, the risk associated with radiolabelled studies can be quantified and minimised by careful design. In contrast, the risk posed by an NCE is not fully quantifiable since safety data available prior to a clinical study may be limited to animal studies and limited phase 2 studies in adults. The other important difference is that deposition studies cannot answer clinically important questions. While the information may be interesting and may modify future clinical studies, the results by themselves cannot answer fundamental questions regarding efficacy and safety. In this respect they are analogous to the phase 2 pharmacokinetic studies that precede clinical trials. For these reasons a clear understanding of the field of aerosol therapy, the options available when considering a particular question, and the limitations of deposition studies, is required when contemplating a study.