Response-dose ratio as an index of bronchial responsiveness to hypertonic saline challenge in an epidemiological survey of asthma in Polish children

Halotherapy-An Ancient Natural Ally in the Management of Asthma: A Comprehensive Review

The increasing production of modern medication emerges as a new source of environmental pollution. The scientific community is interested in developing alternative, ecological therapies in asthma. Halotherapy proved its benefits in asthma diagnosis, treatment, and prevention and may represent a reliable therapeutic addition to the allopathic treatment, due to its ecological and environment-friendly nature, in order to prevent or prolong the time to exacerbations in patients with asthma. We aimed to review up-to-date research regarding halotherapy benefits in asthma comprehensively. We searched the electronic databases of PubMed, MEDLINE, EMBASE for studies that evaluated the exposure of asthmatic patients to halotherapy. Eighteen original articles on asthma were included. Five studies in adults and five in children assessed the performance of hypertonic saline bronchial challenges to diagnose asthma or vocal cord dysfunction in asthmatic patients. Three papers evaluated the beneficial effects of halotherapy on mucociliary clearance in asthmatic adults. The therapeutic effect of halotherapy on acute or chronic asthma was appraised in three studies in adults and one in children. The preventive role was documented in one paper reporting the ability of halotherapy to hinder nocturnal asthma exacerbations. All studies seem to sustain the overall positive effects of halotherapy as adjuvant therapy on asthma patients with no reported adverse events. Halotherapy is a crucial natural ally in asthma, but further evidence-based studies on larger populations are needed.

Diagnostic value of the hypertonic saline bronchial provocation test in children with asthma using the high-power aerosol provocation system

Objective: This study aimed to evaluate the diagnostic value of the modified hypertonic saline bronchial provocation test (HS-BPT) for children with asthma by using the high-power Aerosol Provocation System (APS).Methods: A total of 330 children suspected of having asthma and receiving HS-BPT-APS were included in this prospective survey conducted in Guangzhou, China from February 2017 to September 2018. The positive rate of HS-BPT-APS and the volume and types of adverse reactions were observed. There was also a retrospective cohort of 123 children with suspected asthma who underwent a methacholine BPT from 2015 to 2017. Using the method of nearest neighbor matching, a comparison was made of the positive rate and adverse reaction between the methacholine BPT group and HS-BPT-APS group.Results: The total positive rate of HS-BPT-APS was 43.9%. Common adverse reactions included cough, wheezing and chest tightness. There were no serious adverse reactions. Results of nearest neighbor matching showed a difference in the positive rate between the methacholine BPT group and HS-BPT-APS group (8.1% vs 18.2%, p = 0.026), but there was no statistically significant difference between the age groups in patients who received the methacholine BPT or HS-BPT-APS. There was a similar adverse reaction rate in the two groups (p = 0.609).Conclusions: HS-BPT-APS is simple, safe, and time-saving, with few adverse reactions. The positive rate of HS-BPT-APS was higher than that of methacholine BPT in children with asthma. HS-BPT-APS may be a valuable tool in the diagnosis of children with asthma, and further study is required.

Avaliação da hiperresponsividade brônquica à solução salina hipertônica em crianças e adolescentes

OBJETIVO: Avaliar a hiperresponsividade brônquica à solução salina hipertônica a 4,5% como método alternativo a outros agentes broncoconstritores e sua relação com a sensibilização alérgica do paciente. MÉTODOS: Estudo transversal, experimental, com 85 indivíduos assim distribuídos: 45 no grupo de asmáticos e 17 no grupo controle não asmáticos e não alérgicos, que completaram o teste. Para nebulizar a solução salina hipertônica foi utilizado um nebulizador ultra-sônico de grande volume, sucessivamente durante 0,5, 1, 2, 4 e 8 minutos até haver queda > 15% em relação ao volume expiratório forçado no primeiro segundo basal. A dosagem de imunoglobulina E específica ao Dermatophagoides pteronyssinus por ImmunoCap foi considerada positiva quando > 0,35 kU/L. RESULTADOS: No grupo de asmáticos, 36 apresentaram queda média do volume expiratório forçado no primeiro segundo de 27,4% após nebulização de solução salina hipertônica. Nenhum do grupo controle (imunoglobulina E < 0,35 kU/L) apresentou resposta à solução salina hipertônica e a queda média do volume expiratório forçado no primeiro segundo foi de 9%. Nove asmáticos tiveram provocação brônquica negativa. A freqüência de provocação brônquica positiva foi maior nos indivíduos com imunoglobulina E específica elevada, o que indica uma relação entre hiperresponsividade brônquica e o nível sérico de imunoglobulina E específica. A sensibilidade do teste foi de 80% e a especificidade de 92%. CONCLUSÃO: A inalação de solução salina hipertônica é um método de provocação útil para avaliar hiperresponsividade brônquica em crianças e adolescentes, com adequadas sensibilidade e especificidade, além do baixo custo e necessidade de poucos equipamentos.

Methods for "indirect" challenge tests including exercise, eucapnic voluntary hyperpnea, and hypertonic aerosols

Bronchial provocation tests that use stimuli that act indirectly to cause airway narrowing have a high specificity for identifying people with active asthma who have the potential to respond to treatment with antiinflammatory drugs. The first test to be developed was exercise and it was used to assess the efficacy of drugs such as sodium cromoglycate. Eucapnic voluntary hyperpnea was developed later, as a surrogate test for exercise. Hypertonic aerosols were introduced to mimic the dehydrating effects of evaporative water loss that occurs during hyperpnea. A wet aerosol of 4.5% saline or a dry powder formulation of mannitol is used. At present the indirect challenge tests are becoming increasingly recognised as appropriate for monitoring treatment with inhaled steroids. Indirect tests identify those with potential for exercise-induced bronchoconstriction, an important problem for some occupations, such as the defence forces, fire fighters and the police force and for some athletic activities. The advantage in using an indirect challenges, over a direct challenge with a single pharmacological agonist, is that a positive response indicates that inflammatory cells and their mediators (prostaglandins, leukotrienes and histamine) are present in the airways in sufficient numbers and concentration to indicate that asthma is active at the time of testing. The corollary to this is that a negative test in a known asthmatic indicates good control or mild disease. Another advantage is that healthy subjects do not have significant airway narrowing to indirect challenge tests. The protocols used for challenge with indirectly acting stimuli are presented in detail.

Hypertonic saline challenge tests in the diagnosis of bronchial hyperresponsiveness and asthma in children

The hypertonic saline challenge test is the recommended method to assess bronchial hyperresponsiveness in the International Study of Asthma and Allergies in Childhood (ISAAC). The sensitivity of this procedure to assess asthma symptoms, however, has been reported to vary among study centers. The purpose of our study was to evaluate the value of this provocation test in an epidemiological survey in children, and to relate the degree of bronchial hyperresponsiveness to the severity of asthma symptoms. All 11-13-year-old children from 16 randomly selected schools in Linköping, Sweden received a questionnaire regarding respiratory symptoms and allergic disease. Skin prick tests with eight inhalant allergens were performed. In addition, all children with wheeze over the past 12 months (current wheeze) and a random sample of children without current wheeze were invited to perform hypertonic saline provocation tests. A complete data set was available for 170 children, including 50 with and 120 without current wheeze. Bronchial hyperresponsiveness (BHR) was defined as at least 15% decline in FEV1. The degree of BHR was represented by the response/dose ratio, i.e. the fall in FEV1 divided by total dose of inhaled saline. The severity of asthma symptoms was classified by the number of wheezing episodes over the past 12 months. 'Asthma ever' was defined by a combination of symptoms in the questionnaires. Children with 'asthma ever' and current wheeze were considered as having current asthma. Current atopic asthma was defined as current asthma with at least one positive skin prick test. The sensitivity of the procedure to detect 'asthma ever', current asthma and current atopic asthma was 62, 61 and 83%, and the specificity 83, 81 and 60%, respectively. The positive challenge rate was 52, 34, 13 and 7% among current wheezers, previous wheezers, non-wheezers with a history of allergy and healthy children. The degree of bronchial hyperresponsiveness increased with the number of wheezing episodes. Thus, the median and range of the response/dose ratio were 4.8%/ml (2.1-14.8), 2.6%/ml (0.7-8.6) and 1.3%/ml (0.8-2.7), respectively, for children with >/= 4 episodes, 1-3 episodes and no wheezing episodes over the past 12 months (p<0.001). In conclusion, hypertonic saline provocation test is useful as a tool to detect asthma in epidemiological studies in children. The degree of bronchial hyperresponsiveness, as represented by the response/dose ratio, reflects the severity of asthma symptoms.