Dyspnea in Children: What is driving it and how to approach it

Comparison of the modified shuttle walk test in children with cystic fibrosis and healthy controls

OBJECTIVE

To evaluate and compare performance in the modified shuttle walk test (MSWT) with cardiorespiratory parameters and respiratory muscle strength in children with cystic fibrosis (CF) and healthy controls.

METHODS

A cross-sectional study with children divided into the CF group (CFG) and healthy control group (HCG). Two MSWTs were performed and the data from the test with the longest distance walked and its cardiorespiratory parameters (blood pressure, respiratory rate, heart rate (HR), oxygen saturation, and dyspnea sensation) were considered, the last three every 4 levels. Respiratory muscle strength was evaluated using a manometer. The Wilcoxon test was used to compare the parameters before and after the MSWT, and the Mann-Whitney and independent t-tests were applied to compare the data between the groups. The distance walked and its association with the variation in cardiorespiratory parameters and respiratory muscle strength were analyzed by Spearman's correlation.

RESULTS

Sixty-two children (31 in each group) participated, with an average age of 10.2 (2.1) years. Children with CF had poorer performance in the average distance walked (CFG 716.7 (274.3)) when compared to the HCG (948.0 (202.8)). Both groups exhibited an increase in all the cardiorespiratory parameters at the end of the test, but the CFG displayed less variation in some parameters. Children with CF presented a positive correlation between distance walked and respiratory muscle strength, HR variation, and systolic blood pressure.

CONCLUSIONS

There was no difference in respiratory muscle strength between the groups. In the CFG, the greater the respiratory muscle strength, the better the performance in the MSWT. The CFG exhibited less variation in cardiorespiratory parameters than the HCG.

Impact of Forced Exhalation Maneuvers During Spirometry on Airway Resistance Measured by Oscillometry in Healthy Children

OBJECTIVE

To analyze the impact of repeated forced spirometry maneuvers on oscillometry parameters of healthy children.

METHODS

This is a cross-sectional study with healthy children (6-12 y old) from schools in Florianopolis-SC/Brazil. Good health condition was confirmed through questionnaires, health history, and normal spirometry. Spirometry maneuvers and impulse oscillometry were conducted according to the American Thoracic Society guidelines. The school children were grouped according to the number of spirometry maneuvers performed: 1) 3 maneuvers; 2) 4 maneuvers and 3) 5 to 8 maneuvers. The following oscillometry values were considered: at rest (T₀); after the first spirometry maneuver (T₁); and after the last maneuver (T₂), according to the groups' allocation. The mixed model ANOVA was applied to verify the interaction of oscillometry parameters in all 3 moments and groups. The Friedman test was used for analysis of Fres (p < 0.05).

RESULTS

In 149 school children (mean age: 9.13 y old ± 1.98), there was a significant increase in Z5, R5, R20, and X5 values at rest and after the first spirometry maneuver, and values at rest and after the last maneuver in all groups. The effects on analyzed variables were significant in Z5 (F: 12.35; gl: 2; p < 0.001), R5 (F: 11.14; df: 2, p < 0.001), R20 (F: 7.53; df: 2, p < 0.001), and X5 (F: 4.30; df: 2, p = 0.014).

CONCLUSION

There were changes in respiratory mechanics after spirometry, like the increase in baseline Z5, R5, R20, and X5 after the first forced spirometry maneuver, and in comparison to the last maneuver obtained.

Exercise-Induced Bronchoconstriction in Children

Exercise-induced bronchoconstriction (EIB) is a transient airflow obstruction, typically 5-15 min after physical activity. The pathophysiology of EIB is related to the thermal and osmotic changes of the bronchial mucosa, which cause the release of mediators and the development of bronchoconstriction in the airways. EIB in children often causes an important limitation to physical activities and sports. However, by taking appropriate precautions and through adequate pharmacological control of the condition, routine exercise is extremely safe in children. This review aims to raise awareness of EIB by proposing an update, based on the latest studies, on pathological mechanisms, diagnosis, and therapeutic approaches in children.

The Need for Testing-The Exercise Challenge Test to Disentangle Causes of Childhood Exertional Dyspnea

Exertional dyspnea is a common symptom in childhood which can induce avoidance of physical activity, aggravating the original symptom. Common causes of exertional dyspnea are exercise induced bronchoconstriction (EIB), dysfunctional breathing, physical deconditioning and the sensation of dyspnea when reaching the physiological limit. These causes frequently coexist, trigger one another and have overlapping symptoms, which can impede diagnoses and treatment. In the majority of children with exertional dyspnea, EIB is not the cause of symptoms, and in asthmatic children it is often not the only cause. An exercise challenge test (ECT) is a highly specific tool to diagnose EIB and asthma in children. Sensitivity can be increased by simulating real-life environmental circumstances where symptoms occur, such as environmental factors and exercise modality. An ECT reflects daily life symptoms and impairment, and can in an enjoyable way disentangle common causes of exertional dyspnea.

Pediatric Dysfunctional Breathing: Proposed Components, Mechanisms, Diagnosis, and Management

Dysfunctional breathing (DB) is an overarching term describing deviations in the normal biomechanical patterns of breathing which have a significant impact on quality of life, performance and functioning. Whilst it occurs in both children and adults, this article focuses specifically on children. DB can be viewed as having two components; breathing pattern disorder (BPD) and inducible laryngeal obstruction (ILO). They can be considered in isolation, however, are intricately related and often co-exist. When both are suspected, we propose both BPD and ILO be investigated within an all-encompassing multi-disciplinary dysfunctional breathing clinic. The MDT clinic can diagnose DB through expert history taking and a choice of appropriate tests/examinations which may include spirometry, breathing pattern analysis, exercise testing and laryngoscopic examination. Use of the proposed algorithm presented in this article will aid decision making regarding choosing the most appropriate tests and understanding the diagnostic implications of these tests. The most common symptoms of DB are shortness of breath and chest discomfort, often during exercise. Patients with DB typically present with normal spirometry and an altered breathing pattern at rest which is amplified during exercise. In pediatric ILO, abnormalities of the upper airway such as cobblestoning are commonly seen followed by abnormal activity of the upper airway structures provoked by exercise. This may be associated with a varying degree of stridor. The symptoms, however, are often misdiagnosed as asthma and the picture can be further complicated by the common co-presentation of DB and asthma. Associated conditions such as asthma, extra-esophageal reflux, rhinitis, and allergy must be treated appropriately and well controlled before any directed therapy for DB can be started if therapy is to be successful. DB in pediatrics is commonly treated with a course of non-pharmaceutical therapy. The therapy is provided by an experienced physiotherapist, speech and language therapist or psychologist depending on the dominant features of the DB presentation (i.e., BPD or ILO in combination or in isolation) and some patients will benefit from input from more than one of these disciplines. An individualized treatment program based on expert assessment and personalized goals will result in a return to normal function with reoccurrence being rare.