DHASMANA RESEARCH GROUPResearch at the University of St Andrews School of Medicine
Lower respiratory tract infections make up the 3rd leading cause of death worldwide, and the leading cause in low-income countries1. A diagnosis of ‘Pneumonia’ is given to those with severe infection in whom there is significant inflammation or consolidation of the lung evident on chest x-ray.
The word ‘Pneumonia’ has emerged from Greek origins that combine the word ‘pneumo-‘ reflecting the lungs with the suffix ‘-ia’ meaning ‘disease’. The literal meaning might be ‘disease of the lung’, although in the modern world this tends to be synonymous with infection. In clinical medicine, the term ‘Pneumonia’ is still used to describe various diseases of the lung outside of infection, most commonly where the ‘interstitial pneumonias’ are concerned; a group of disorders associated with significant inflammation without infection and of various underlying causes2.
The research interest in respiratory infection and in Pneumonia, in particular, is in how we can improve our detection of the causative pathogen, and in so doing how we can provide the best antibiotic strategy. The usual test of bacterial culture can take 48-72 hours to get a pathogen name and antibiotic sensitivities, by which time the patient has typically improved with empirical antibiotics given on arrival to hospital. It is often unclear at this point whether the patient improved because of the antibiotics, or despite them! Newer techniques involve PCR, and still newer techniques involve the quantification of viable genetic material of different types in a rapid typically semi-automated system that can provide the results within hours of receipt of the sample. However, there are many difficulties with such techniques, not least refining and validating the tests so that there is an appropriate combination of test robustness and cost-effectiveness that supports its use.
Interstitial Lung Disease
There are reported to be more than 200 types of interstitial lung disease (ILD) however, only a small number of them are relevant in mainstream respiratory medicine. ILD is the presence of inflammation and scar formation in the areas of the lung outside of the airways, in contrast to bronchiectasis which is an airway disease process, and the result is that the air sacs that normally mediate efficient gas transfer of oxygen into the bloodstream and carbon dioxide out of it are damaged. ‘Fibrosis’ reflects more established inflammation and scar formation, although the term ‘scar’ is probably an unhelpful term as it suggests a more fixed process that often it is not.
ILD leads typically to breathlessness and cough, and in time, can lead to significant disability and respiratory failure, even secondary heart failure. Of the many ILD types, the importance is in identifying those that are progressive, reversible and treatable, and then commencing appropriate therapy in this context.
Idiopathic Pulmonary Fibrosis (IPF) is the commonest type of ILD, and as the name implies has no single identifiable cause. However, it is nevertheless a distinct clinico-pathological entity and runs a distinct progressive clinical course. Whilst the speed of the progression is difficult to predict at the outset, it can be severe and can lead to a rapid decline. Indeed, the median survival is in the order of 3 years, and much more grim than most cancers in the UK.
We have an interest in better understanding ILD and IPF in Fife and are working with colleagues to improve this understanding further. We are keen to assess the size of the problem as we develop improved ways of managing those suspected to have the condition. From recent data, it has become apparent that IPF poses a significant burden in Fife and is associated with significant healthcare interaction and cost3. There are many aspects to care in ILD, and a number of research areas of interest to us, including related to infection and to imaging.
Remote oxygen sensing – through an Xbox!
Blood oxygen saturations are currently measured by various devices that either infer values from superficial contact probes, or take direct measurements from blood sampling. In the former, skin contact is required and can complicate the care of the patient and is prone to fluctuation and error. In the latter, the test is invasive, painful and can cause complications that include bleeding and formation of thrombus. Studies are currently under way to assess the potential of remote systems that utilize spectral differences in oxygenated and deoxygenated blood to calculate oxygen saturations. The challenge will be to produce a system that is robust, reproducible and cost-effective, but good progress is being made in Fife4.
Where there is permanent damage to airways, typically from a primary infection, patients can develop a vicious cycle of infection where new respiratory infection causes localized damage, inflammation and destruction and vulnerability to new respiratory infection, which then recurs, so causing further damage, inflammation, and so it goes on. The airways become permanently inflamed, thickened and then wider, so causing problems with clearance of viscid secretions. This leads to recurrent infections and can lead to significant disability and sometimes to respiratory failure.
The research interest in this group is in how we might better manage those patients with recurrent severe infections, and how to give them the best support, antibiotic and otherwise, both in the short-term and the long-term. There is a strong local interest in Fife and in neighbouring Tayside, and there is growing interest both nationally and internationally in better understanding and managing this chronic condition.
- Belloli, EA., Beckford, R, Hadley, R, & Flaherty, KR (2015). Idiopathic non-specific interstitial pneumonia. Respirology (Carlton, Vic.). http://doi.org/10.1111/resp.12674
- Dhasmana DJ, Harrison F, Hartley T, Szapiro D, Evaluation of the healthcare burden of Idiopathic Pulmonary Fibrosis (IPF) in Fife, Scotland (2016), ATS Abstracts, May 13-18th, San Francisco, USA http://med.st-andrews.ac.uk/dhasmana/publications/
- Harris-Birtill D, Morrison D, Dhasmana DJ, Remote sensing of heart rate and blood oxygenation using gaming camera-based technology (2015); ‘Transforming Healthcare with IT Conference, October, Bengaluru, India http://med.st-andrews.ac.uk/dhasmana/publications/