International consensus on (ICON) pediatric asthma

Asthma is the most common chronic lower respiratory disease in childhood throughout the world. Several guidelines and/or consensus documents are available to support medical decisions on pediatric asthma. Although there is no doubt that the use of common systematic approaches for management can considerably improve outcomes, dissemination and implementation of these are still major challenges. Consequently, the International Collaboration in Asthma, Allergy and Immunology (iCAALL), recently formed by the EAACI, AAAAI, ACAAI, and WAO, has decided to propose an International Consensus on (ICON) Pediatric Asthma. The purpose of this document is to highlight the key messages that are common to many of the existing guidelines, while critically reviewing and commenting on any differences, thus providing a concise reference. The principles of pediatric asthma management are generally accepted. Overall, the treatment goal is disease control. To achieve this, patients and their parents should be educated to optimally manage the disease, in collaboration with healthcare professionals. Identification and avoidance of triggers is also of significant importance. Assessment and monitoring should be performed regularly to re-evaluate and fine-tune treatment. Pharmacotherapy is the cornerstone of treatment. The optimal use of medication can, in most cases, help patients control symptoms and reduce the risk for future morbidity. The management of exacerbations is a major consideration, independent of chronic treatment. There is a trend toward considering phenotype-specific treatment choices; however, this goal has not yet been achieved.

Perception of induced bronchoconstriction in a community sample of adolescents

BACKGROUND

Poor perception of asthma symptoms has been cited as a risk factor for asthma death, yet there is no consensus as to the best way to characterize perception, and little is known about perception in normative samples. Hypoperceivers are of clinical interest because of risks of undertreatment; hyperperceivers are at risk for adverse iatrogenic effects caused by overtreatment.

OBJECTIVE

This study investigates perception of methacholine-induced bronchoconstriction in 175 adolescents.

METHODS

Breathlessness was rated after each inhalation by using the Borg scale. Perception groups were calculated on the basis of change from placebo Borg to high Borg scores (perception score at the highest methacholine dose). Subjects were called hypoperceivers if their Borg change score was greater than 1 SD below the mean for their FEV(1) group, hyperperceivers if their Borg change score was greater than 1 SD above the mean for their FEV(1) group, and accurate perceivers otherwise.

RESULTS

For subjects with an FEV(1) drop of less than 10%, accurate perceivers had a change in Borg score of 1.4 or less, and hyperperceivers had a change of greater than 1.4. For a drop in FEV(1) between 10% and 19%, hypoperceivers had a change in Borg score of less than 0.2, accurate perceivers had a change between 0.2 and 2.1, and hyperperceivers had a change of greater than 2.1. For those with an FEV(1) drop of 20% or greater, hypoperceivers had a Borg change of less than 0.2, accurate perceivers had a change between 0.2 and 2.6, and hyperperceivers had a change of greater than 2.6. No differences in age, sex, placebo Borg ratings, baseline pulmonary functions, PC(20) values, or psychologic variables were found among perception groups.

CONCLUSION

This study provides reference Borg values during methacholine challenge for 175 community adolescents.

Measurement of children's asthma medication adherence by self report, mother report, canister weight, and Doser CT

BACKGROUND

Accurate assessment of medication adherence has been difficult to achieve but is essential to drug evaluation in clinical trials and improved outcomes in clinical care.

OBJECTIVE

This study was conducted to compare four adherence assessment methods: child report, mother report, canister weight, and electronic measurements of metered dose inhaler (MDI) actuation.

METHODS

Participants included 27 children with mild-to-moderate asthma who were followed prospectively for 6 months. All patients used an MDI equipped with an electronic Doser attached to their inhaled steroid. At each 2-month follow-up visit, Doser and canister weight data were recorded, while child and mother were interviewed separately regarding medication use.

RESULTS

Children and mothers reported, on average, over 80% adherence with the prescribed inhaled steroid. Canister weight revealed, on average, adherence of 69%, significantly lower than self-report. When adherence recorded by the electronic Doser was truncated to no more than 100% of prescribed daily use, average adherence was 50%. Older children and adolescents, nonwhite children, and those from poorer functioning families were least adherent.

CONCLUSIONS

Electronic adherence monitoring was significantly more accurate than self-report or canister weight measures. Such accuracy is an essential prerequisite to increasing understanding of the treatment, setting, and patient factors that influence adherence, and to the consequent design of effective intervention strategies.

Pharmacological interventions. Childhood asthma

Airway inflammation is present in early asthma. Chronic inflammation seems to be associated with airway remodelling and reduced growth of lung function. An inverse relationship between lung function and duration of asthma or an increase in bronchial reactivity with asthma duration has been reported in many studies. Several trials have found that late use of inhaled corticosteroids is associated with a smaller effect on bronchial hyperreactivity and lung function compared with early use. Furthermore, it has been suggested that early anti-inflammatory treatment may also influence long-term outcome. These findings have elicited the hope that it might be possible to cause disease resolution or modify the natural course of the disease. It has been hypothesized that there may be a window of opportunity in relation to the treatment of asthma after which remodelling and changes in lung function occur which cannot be reversed. However, just when this window of opportunity presents in the progression of the disease, or at what stage early intervention should be initiated, has not been clearly defined. Early pharmacological intervention in children <3 yrs of age is complicated by the fact that treatment will be given to a large number of children who will never develop persistent asthma. This must be considered when designing the studies addressing the various research questions about early pharmacological intervention. Studies in young children should probably be conducted in both high- and low-risk patients. Older patients with apparently mild disease are the main candidates for placebo-controlled trials. Patients with a greater disease severity are more suitable for studies comparing intervention with different drugs or different doses of drug.

Psychological change associated with theophylline treatment of asthmatic children: a 6-month study

Theophylline has been associated with a variety of behavioral side effects in asthmatic children. This study was a 6-month investigation of the relationship between theophylline treatment and psychological changes in 8 to 16 year old asthmatic children. Included were a group receiving theophylline (n = 19), a control group not receiving theophylline (n = 44), and a nonasthmatic control group (n = 24). The three groups had similar age, socioeconomic status, and IQ. The two groups of children with asthma demonstrated greater emotional dysfunction, characterized by tendency toward withdrawal and depression, than the nonasthmatic control group. Each of five assessment appointments (baseline and 1 week, 1 month, 3 months, and 6 months after beginning theophylline treatment) included measures of pulmonary function, attention, impulsivity, memory, fine motor control, activity level, self-reported mood, and parental observation of difficult behavior. Pulmonary functions were lower in the theophylline group at baseline but improved significantly after commencement of theophylline therapy. Over the 6-month interval, children in the theophylline group demonstrated improved scores on a laboratory measure of attention, while their parents reported increased conduct problems and hyperactivity. On the whole, psychological score changes were subtle, and no other between-group differences emerged in the remaining laboratory measures.

Beta-adrenergic receptors of human polymorphonuclear leukocytes

125I-iodohydroxybenzylpindolol (IHYP) is a beta-adrenergic antagonist used as a ligand for the characterization of beta-adrenergic receptors in various cell preparations. Since IHYP may be adsorbed to surfaces such as test tubes and pipet tips, it is necessary to measure the actual free concentration of IHYP in the incubation solution. With this modification, the number of beta-adrenergic receptors in human peripheral PMNs can be determined with greater precision.