Predictors of correct technique in patients using pressurized metered dose inhalers

Background: Correct inhaler technique is recommended by guidelines for optimum asthma care. The objective of the study is to determine real life predictors of correct pressurized metered dose inhaler (pMDI) technique in Asthma and COPD patients. Methods: Two hundred eight adult patients aged 18+ from respiratory outpatients (69.2%) and the community on regular pMDI for a diagnosis of Asthma (78.9%) or COPD, were recruited. A questionnaire containing 31 possible predictors was administered and pMDI technique with or without spacer was observed by trained researchers on 12 point steps, of which 4 were considered critical. Results: 23.1% of patients had no errors in inhaler technique and 32.2% had no critical errors. Patients had a median of 10 correct steps (IQR9-11), and 3(IQR2-4) correct critical steps. Using binary logistic regression the predictors of 10 correct steps were, other healthcare professional (pharmacist, nurse, physiotherapist) explained OR 3.73(1.63–8.54, p = 0.001), male gender 2.70(1.35–5.39, p = 0.004), self-score 1–10 1.21(1.05–1.39, p = 0.007), spacer use 0.38(0.19–0.79, p = 0.007), inhaled steroid 3.71(1.34–10.25, p = 0.01), heart disease 0.31(0.13–0.77, p = 0.01), pneumococcal vaccine 2.48(1.0–6.15, p = 0.043), education level 1–4 1.44(1.00–2.06, p = 0.05) and respiratory physician explained 0–7 times, 1.11(0.99–1.26, p = 0.08). Using ordinal logistic regression, predictors for correct critical steps 0–4, were: technique self-score 1–10 1.2(1.05–1.42, p = 0.006), inhaled corticosteroid use 2.78(1.1–7.31, p = 0.03) and education level 1–4 1.41(1.02–1.95, p = 0.03 Times respiratory physician explained inhaler technique 0–7 1.1(0.98–1.24, p = 0.1), married status 1.55(0.85–2.82, p= 0.15), hypercholesterolaemia 0.52(0.25–1.01, p = 0.054) and male gender 1.76(0.97–3.18, p = 0.06). Conclusions: Known predictors of correct pMDI use, such as gender and education level were confirmed, while age and concomitant use of dry powder inhaler were not. Pneumococcal vaccination and awareness of steroid side effects were possible novel positive predictors, while the use of a spacer and co-morbidity with heart disease were found to be negative predictors. Patients’ self-assessment correlated well with actual performance. This information may be useful in defining approaches to optimize inhaler techniques which are so susceptible to human error.peer-reviewe

A respiratory/Hirschsprung phenotype in a three‐generation family associated with a novel pathogenic PHOX2B splice donor mutation

Background: Mutations in the PHOX2B gene cause congenital central hypoventilation syndrome (CCHS), a rare autonomic nervous system dysfunction disorder characterized by a decreased ventilatory response to hypercapnia. Affected subjects develop alveolar hypoventilation requiring ventilatory support particularly during the non-REM phase of sleep. In more severe cases, hypoventilation may extend into wakefulness. CCHS is associated with disorders characterized by the defective migration/differentiation of neural crest derivatives, including aganglionic megacolon or milder gastrointestinal phenotypes, such as constipation. Most cases of CCHS are de novo, caused by heterozygosity for polyalanine repeat expansion mutations (PARMs) in exon 3. About 10% of cases are due to heterozygous non-PARM missense, nonsense or frameshift mutations. Methods: We describe a three-generation Maltese-Caucasian family with a variable respiratory/Hirschsprung phenotype, characterized by chronic constipation, three siblings with Hirschsprung disease necessitating surgery, chronic hypoxia, and alveolar hypoventilation requiring non-invasive ventilation. Results: The sequencing of PHOX2B revealed a novel heterozygous c.241+2delT splice variant in exon 1 that segregates with the CCHS/Hirschsprung phenotype in the family. The mutation generates a non-functional splice site with a deleterious effect on protein structure and is pathogenic according to ACMG P VS1, PM2, and PP1 criteria. Conclusion: This report is significant as no PHOX2B splice-site mutations have been reported. Additionally, it highlights the variability in clinical expression and disease severity of non-PARM mutations.peer-reviewe

Additional file 1: of Predictors of correct technique in patients using pressurized metered dose inhalers

Dataset. (XLSX 56 kb

Additional file 2: of Predictors of correct technique in patients using pressurized metered dose inhalers

Questionnaire. (PDF 157 kb

An assessment of the performance of low dose CT thorax (CT pneumonia) as a screening tool in the diagnosis of Covid-19

The advent of the COVID-19 pandemic in Malta led to a number of innovations in terms of work practices, including the introduction of blanket swabbing of all hospital admissions for Covid-19 using PCR nasopharyngeal swab as well as the temporary indiscriminate use of Low dose CT Thorax (CT Pneumonia) as a screening tool in all patients with respiratory symptoms or fever, a recent positive contact, history of travel abroad and all health care workers presenting to hospital. Our aim was to assess the performance of CT pneumonia as a screening tool for Covid-19 in a cohort of patients presenting to large teaching hospital. 661 screening CTs performed between 29/3/20 and 14/4/20 were included. 4 CTs (0.6%) were reported as positive for Covid-19, 45 (6.8%) were reported as 'indeterminate' with the remaining 612 (92.6%) reported as ‘alternative diagnosis’ or negative. Covid-19-PCR-swab was positive in 21 patients (3.2%). Of these, 14 (66.7%) had a Negative CT Pneumonia, 6 (28.6%) had a CT reported as 'Alternative Diagnosis' and 1 (4.8%) had a positive CT for Covid-19. Among the remaining cases testing negative on PCR swab, 3 were reported as having a positive CT and in 2 of these cases, Covid-19 was confirmed using serology testing. Within the entire population of patients who underwent CT Pneumonia, the overall sensitivity for Covid-19 was 13.0%, specificity was 99.8%, positive predictive value was 75.0% and negative predictive value was 96.7%. CT Pneumonia had a low sensitivity for Covid-19 in our cohort of patients making it a poor screening tool, however it may have a role in those who test negative on PCR swab where a high index of suspicion persists.peer-reviewe