Cough quality in children: a comparison of subjective vs. bronchoscopic findings

BACKGROUND: Cough is the most common symptom presenting to doctors. The quality of cough (productive or wet vs dry) is used clinically as well as in epidemiology and clinical research. There is however no data on the validity of cough quality descriptors. The study aims were to compare (1) cough quality (wet/dry and brassy/non-brassy) to bronchoscopic findings of secretions and tracheomalacia respectively and, (2) parent's vs clinician's evaluation of the cough quality (wet/dry). METHODS: Cough quality of children (without a known underlying respiratory disease) undergoing elective bronchoscopy was independently evaluated by clinicians and parents. A 'blinded' clinician scored the secretions seen at bronchoscopy on pre-determined criteria and graded (1 to 6). Kappa (K) statistics was used for agreement, and inter-rater and intra-rater agreement examined on digitally recorded cough. A receiver operating characteristic (ROC) curve was used to determine if cough quality related to amount of airway secretions present at bronchoscopy. RESULTS: Median age of the 106 children (62 boys, 44 girls) enrolled was 2.6 years (IQR 5.7). Parent's assessment of cough quality (wet/dry) agreed with clinicians' (K = 0.75, 95%CI 0.58–0.93). When compared to bronchoscopy (bronchoscopic secretion grade 4), clinicians' cough assessment had the highest sensitivity (0.75) and specificity (0.79) and were marginally better than parent(s). The area under the ROC curve was 0.85 (95%CI 0.77–0.92). Intra-observer (K = 1.0) and inter-clinician agreement for wet/dry cough (K = 0.88, 95%CI 0.82–0.94) was very good. Weighted K for inter-rater agreement for bronchoscopic secretion grades was 0.95 (95%CI 0.87–1). Sensitivity and specificity for brassy cough (for tracheomalacia) were 0.57 and 0.81 respectively. K for both intra and inter-observer clinician agreement for brassy cough was 0.79 (95%CI 0.73–0.86). CONCLUSIONS: Dry and wet cough in children, as determined by clinicians and parents has good clinical validity. Clinicians should however be cognisant that children with dry cough may have minimal to mild airway secretions. Brassy cough determined by respiratory physicians is highly specific for tracheomalacia

Change in Fev1 and Feno Measurements as a Predictor of Future Asthma Outcomes in Children

BACKGROUND: Repeated measurements of spirometry and fractional exhaled nitric oxide (FeNO) are recommended as part of the management of childhood asthma, but the evidence base for such recommendations is small. We tested the hypothesis that reducing spirometric indices or increasing FeNO will predict poor future asthma outcomes. METHODS: A one-stage individual patient data meta-analysis used data from seven randomised controlled trials where FeNO was used to guide asthma treatment, and where spirometric indices were also measured. Change in %FEV1 and % change in FeNO between baseline and three months were related to having poor asthma control and to having an asthma exacerbation between three and six months after baseline. RESULTS: Data were available from 1112 children (mean age 12.6 years, mean %FEV1 94%). A 10% reduction in %FEV1 between baseline and three months was associated with 28% increased odds for asthma exacerbation [95% CI 3, 58] and with 21% increased odds for having poor asthma control [95% CI 1, 45] six months after baseline. A 50% increase in FeNO between baseline and three months was associated with 11% increase in odds for poor asthma control six months after baseline [95% CI 0, 16]. Baseline FeNO and %FEV1 were not related to asthma outcomes at three months. CONCLUSIONS: Repeated measurements of %FEV1 which are typically within the “normal” range add to clinical risk assessment of future asthma outcomes in children. The role of repeated FeNO measurements is less certain since large changes were associated with small changes in outcome risk

Cough sounds

Cough is an important protective reflex that is essential to protect the airways yet can also signify disease as a symptom of airway disease. It is the most common symptom that results in new medical consultations at least in regions where data is available. Both children and adults can cough for a myriad of reasons. This ranges from cough associated with simple viral infections to cough secondary to serious airway or lung disorders. Consequently evaluating causes of cough can be quite challenging. The mechanism of cough involves the central and peripheral neural systems, muscular and airway mechanisms. The sound of cough is influenced by various physiological factors such as age and sex and by pathological factors such as muscle weakness, airway obstruction and excessive mucus production. This chapter briefly reviews factors influencing cough sounds and recorders. As cough is a cardinal symptom of airway diseases and many respiratory illnesses, a description of typical cough quality in various respiratory conditions is provided. We also briefly discuss the availability and developments in software, apps and cough measurement devices that unfold a new exciting field of study and research in our era of advancing technology