Diagnostic utility of spirometry for children with induced laryngeal obstruction or chronic non-specific cough

PURPOSE

To determine the diagnostic utility of spirometry in distinguishing children with Induced Laryngeal Obstruction (ILO) or chronic non-specific cough (a.k.a. tic cough) from those with mild or moderate to severe asthma.

METHODS

Retrospective cross sectional design. Children diagnosed with ILO (N = 70), chronic non-specific cough (N = 70), mild asthma (N = 60), or moderate to severe asthma (N = 60) were identified from the electronic medical record of a large children's hospital. Spirometry was completed before ILO, non-specific cough, or asthma diagnoses were made by pediatric laryngologists or pulmonologists. Spirometry was performed following American Thoracic Society guidelines and was interpreted by a pediatric pulmonologist. Forced Vital Capacity (FVC), Forced Expiratory Volume in 1 Second (FEV1), FEV1/FVC Ratio (FEV1/FVC), Forced Mid-Expiratory Flow 25--75 % (FEF25-75%), pulmonologist interpretation of flow volume loops, and overall exam findings were extracted from the medical record.

RESULTS

Ninety seven percent of children with ILO or chronic non-specific cough presented with spirometry values within normative range. Patients with ILO, non-specific cough, and mild asthma presented with FVC, FEV1, FEV1/FVC, and FEF25-75% values in statistically similar range. Children with moderate to severe asthma presented with significantly reduced FVC (p < .001), FEV1 (p < .001), FEV1/FVC (p < .001), and FEF25-75% (p < .001) values when compared with patients in the other groups. Flow volume loops were predominantly normal for children with ILO and non-specific cough.

CONCLUSIONS

Findings indicate that ILO and chronic non-specific cough can neither be diagnosed nor differentiated from mild asthma using spirometry alone. Spirometry should therefore be used judiciously with this population, bearing in mind the limitations of the procedure. Future research should determine the most effective and efficient ways of delineating ILO and non-specific cough from other respiratory conditions in children.

Functional Respiratory Disorders in Children

Functional respiratory disorders (FRDs) are those characterized by respiratory symptoms without anatomic or organic etiology. Clinicians caring for children encounter these disorders and should be familiar with diagnosis and treatment. FRDs encompass the habit cough syndrome and its variants, vocal cord dysfunction, hyperventilation disorders, functional dyspnea, and sighing syndrome. Failure to identify these disorders results in unnecessary testing and medication. This article reviews the clinical presentation, manifestation, and treatment of respiratory FRDs in children. How health care providers can successfully identify and treat these reversible conditions in the clinical setting is discussed.

Is hypnotherapy an acceptable treatment option for children with habit cough?

Habit cough is a chronic, persistent dry cough which occurs in children only when awake. It is considered functional (non-organic) and can have a significant impact on the quality of life of the child and their family. One possible treatment option for habit cough is hypnotherapy. At our centre we offered hypnotherapy sessions to patients diagnosed with habit cough, and conducted telephone interviews with patients' parents to determine the acceptability of this therapy. Nine patients' parents were interviewed, and despite being unsure of what to expect with hypnotherapy, all nine found it an acceptable treatment option. Parents reported that hypnotherapy appeared to result in cough reduction or cessation in 6 out of 9 cases.

Hypnosis in paediatric respiratory medicine

Hypnotherapy is an often misunderstood yet effective therapy. It has been reported to be useful within the field of paediatric respiratory medicine as both a primary and an adjunctive therapy. This article gives a brief overview of how hypnotherapy is performed followed by a review of its applications in paediatric patients with asthma, cystic fibrosis, dyspnea, habit cough, vocal cord dysfunction, and those requiring non-invasive positive pressure ventilation. As the available literature is comprised mostly of case series, retrospective studies, and only a single small randomized study, the field would be strengthened by additional randomized, controlled trials in order to better establish the effectiveness of hypnosis as a treatment, and to identify the processes leading to hypnosis-induced physiologic changes. As examples of the utility of hypnosis and how it can be taught to children with respiratory disease, the article includes videos that demonstrate its use for patients with cystic fibrosis.