A rare cause of specific cough in a child: the importance of following-up children with chronic cough

Clinical pathways for chronic cough in children

BACKGROUND

Chronic cough (a cough lasting longer than four weeks) is a common problem internationally. Chronic cough has associated economic costs and is distressing to the child and to parents; ignoring cough may lead to delayed diagnosis and progression of serious underlying respiratory disease. Clinical guidelines have been shown to lead to efficient and effective patient care and can facilitate clinical decision making. Cough guidelines have been designed to facilitate the management of chronic cough. However, treatment recommendations vary, and specific clinical pathways for the treatment of chronic cough in children are important, as causes of and treatments for cough vary significantly from those in adults. Therefore, systematic evaluation of the use of evidence-based clinical pathways for the management of chronic cough in children would be beneficial for clinical practice and for patient care. Use of a management algorithm can improve clinical outcomes; such management guidelines can be found in the guidelines for cough provided by the American College of Chest Physicians (ACCP) and the British Thoracic Society (BTS).

OBJECTIVES

To evaluate the effectiveness of using a clinical pathway in the management of children with chronic cough.

SEARCH METHODS

The Cochrane Register of Controlled Trials (CENTRAL), the Cochrane Airways Group Specialised Register, MEDLINE, EMBASE, review articles and reference lists of relevant articles were searched. The latest search was conducted in January 2014.

SELECTION CRITERIA

All randomised controlled trials of parallel-group design comparing use versus non-use of a clinical pathway for treatment of chronic cough in children (< 18 years of age).

DATA COLLECTION AND ANALYSIS

Results of searches were reviewed against predetermined criteria for inclusion. Two review authors independently selected studies and performed data extraction in duplicate.

MAIN RESULTS

One study was included in the review. This multi-centre trial was based in five Australian hospitals and recruited 272 children with chronic cough. Children were randomly assigned to early (two weeks) or delayed (six weeks) referral to respiratory specialists who used a cough management pathway. When an intention-to-treat analysis was performed, clinical failure at six weeks post randomisation (defined as < 75% improvement in cough score, or total resolution for fewer than three consecutive days) was significantly less in the early pathway arm compared with the control arm (odds ratio (OR) 0.35, 95% confidence interval (CI) 0.21 to 0.58). These results indicate that one additional child will be cured for every five children treated via the cough pathway (number needed to treat for an additional beneficial outcome (NNTB) = 5, 95% CI 3 to 9) at six weeks. Cough-specific parent-reported quality of life scores were significantly better in the early-pathway group; the mean difference (MD) between groups was 0.60 (95% CI 0.19 to 1.01). Duration of cough post randomisation was significantly shorter in the intervention group (early-pathway arm) compared with the control group (delayed-pathway arm) (MD -2.70 weeks, 95% CI -4.26 to -1.14).

AUTHORS' CONCLUSIONS

Current evidence suggests that using a clinical algorithm for the management of children with chronic cough in hospital outpatient settings is more effective than providing wait-list care. Futher high-quality randomised controlled trials are needed to perform ongoing evaluation of cough management pathways in general practitioner and other primary care settings.

Therapy for cough: where does it fall short?

Studies on cough have come a long way but many shortfalls still exist. These shortfalls can be attributed to: the lack of randomized controlled studies with a focus on cough; studies not using robust cough outcome measures, poor definition of target groups in studies and guidelines, the lack of safe and efficacious treatments; difficulty in defining etiological factors, and the lack of data on the predictors of response to therapies for cough dominant etiologies. Addressing shortfalls in cough therapy that focuses on improving the lives of people with cough requires a systematic approach that includes better medications, high quality studies, improved multidisciplinary guidelines and education (of both health professionals and patients). To achieve new cough therapeutics requires an improved understanding of cough in humans (i.e., not just in animals). Development of new medications without substantial adverse events is long awaited for cough.

Clinical pathways for chronic cough in children

BACKGROUND

Chronic cough (a cough lasting longer than 4 weeks) is a common symptom presenting to primary care in Australia and internationally. Chronic cough costs the community, is distressing to parents, and ignoring cough may lead to delayed diagnosis and illness progression of serious underlying respiratory disease. Clinical guidelines have been shown to provide more efficient and effective patient care and can clarify clinical decision making. Cough guidelines have been designed to facilitate management of chronic cough, however treatment recommendations vary and specific clinical pathways for the treatment of chronic cough in children are important, as the cause and treatments for cough in a child vary significantly adults. Therefore, it would be beneficial to clinical practice to systematically evaluate the use of clinical pathways for the treatment of chronic cough in children.

OBJECTIVES

To evaluate the effectiveness of using a clinical pathway in the management of children with chronic cough.

SEARCH STRATEGY

The Cochrane Register of controlled Trials (CENTRAL), the Cochrane Airways Group Specialised Register, MEDLINE, EMBASE, review articles and reference lists of relevant articles were searched. The search was carried out in May 2007.

SELECTION CRITERIA

All randomised controlled trials with parallel group design comparing use vs non-use of a clinical pathway for treatment of chronic cough in children.

DATA COLLECTION AND ANALYSIS

Results of searches were reviewed against the pre-determined criteria for inclusion. Two reviewers independently selected the studies and it was planned that data extraction would have been done in duplicate.

MAIN RESULTS

The search identified 471 potentially relevant titles but no studies met criteria for inclusion in the review.

AUTHORS' CONCLUSIONS

Without further available evidence, recommendations for the use of clinical pathways for the treatment of chronic cough in children cannot be made. Until further evidence is available, the decision for further investigation and treatment for the child presenting with chronic cough should be made on an individual basis (i.e. dependent on symptoms and signs) with consideration for existing data from other Cochrane reviews on specific treatments for cough. Trials are required to provide evidence on the effectiveness of clinical pathways for the treatment of chronic cough in children.

Analysis and evaluation of environmental tobacco smoke exposure as a risk factor for chronic cough

Exposure to environmental tobacco smoke (ETS) and active tobacco smoking has been shown to increase symptoms of bronchial asthma such as bronchoconstriction but effects on other respiratory symptoms remain poorly assessed. Current levels of exposure to tobacco smoke may also be responsible for the development of chronic cough in both children and adults. The present study analyses the effects of tobacco smoke exposure as potential causes of chronic cough. A panel of PubMed-based searches was performed relating the symptom of cough to various forms of tobacco smoke exposure. It was found that especially prenatal and postnatal exposures to ETS have an important influence on children's respiratory health including the symptom of cough. These effects may be prevented if children and pregnant women are protected from exposure to ETS. Whereas the total number of studies adressing the relationship between cough and ETS exposure is relatively small, the present study demonstrated that there is a critical amout of data pointing to a causative role of environmental ETS exposure for the respiratory symptom of cough. Since research efforts have only targeted this effect to a minor extent, future epidemiological and experimental studies are needed to further unravel the relation between ETS and cough.

Analysis of airway secretions in a model of sulfur dioxide induced chronic obstructive pulmonary disease (COPD)

Hypersecretion and chronic phlegm are major symptoms of chronic obstructive pulmonary disease (COPD) but animal models of COPD with a defined functional hypersecretion have not been established so far. To identify an animal model of combined morphological signs of airway inflammation and functional hypersecretion, rats were continuously exposed to different levels of sulfur dioxide (SO2, 5 ppm, 10 ppm, 20 ppm, 40 ppm, 80 ppm) for 3 (short-term) or 20–25 (long-term) days. Histology revealed a dose-dependent increase in edema formation and inflammatory cell infiltration in short-term-exposed animals. The submucosal edema was replaced by fibrosis after long-term-exposure. The basal secretory activity was only significantly increased in the 20 ppm group. Also, stimulated secretion was significantly increased only after exposure to 20 ppm. BrdU-assays and AgNOR-analysis demonstrated cellular metaplasia and glandular hypertrophy rather than hyperplasia as the underlying morphological correlate of the hypersecretion.

In summary, SO2-exposure can lead to characteristic airway remodeling and changes in mucus secretion in rats. As only long-term exposure to 20 ppm leads to a combination of hypersecretion and airway inflammation, only this mode of exposure should be used to mimic human COPD. Concentrations less or higher than 20 ppm or short term exposure do not induce the respiratory symptom of hypersecretion. The present model may be used to characterize the effects of new compounds on mucus secretion in the background of experimental COPD.