The second one is completed by parents and consists of three questions daytime complaints, daytime wheezing and awakenings at night with six response options.
The score ranges from 0 poorest asthma control to 27 optimal asthma control. The ACQ includes 7 questions, 5 related to symptoms, 1 on rescue treatment use and 1 on FEV1 finding; the control is assessed over the preceding week. For children with normal FEV1 a version of five-point questionnaire is preferable Other available scores include the Mini Asthma Quality of Life Questionnaire, validated for adults its counterparts for patients 7—17 years of age is the Pediatric Quality of life Questionnaire and the Royal College of Physicians 3 Questions 13 , The first values the control over the preceding 2 weeks and could be used to assess response to longer-term treatment trials.
The latter although not well validated in both adults and children, could be used in day-to-day clinical practice thanks to his simplicity. This score may be more sensible in children since it reflects the changes in asthma control over a short follow up period and take into account the assessment of exacerbations 18 , Nevertheless, children may experience more exacerbations during one season vs. SIGN guidelines also recommend the use of the Pediatric Asthma Quality of life Questionnaire PAQLQ to assess health-related QoL in children with asthma and including 23 questions that investigate 4 domains symptoms, activity limitations, emotional function, and environmental stimuli , validated for the age range 7—17 years 21 , A further questionnaire is the Asthma Therapy Assessment Questionnaire ATAQ , a item parent-completed questionnaire, developed to assist clinicians to identify children at risk for adverse outcomes of asthma and including 4 different domains on symptom control, behavior and attitude barriers, self-efficacy barriers, and communication gaps A new score defined Severe Asthma questionnaire SAQ is being validated in adults; it can be used to detect the impact of both asthma symptoms and treatment on quality of life Usually, in daily practice, the possibility of using asthma control questionnaires and above all quality of life measures is significantly higher in the pediatric clinical routine.
Certainly, in the pediatric age the supervision of parents ensures a further control and makes these scores more reliable than those compiled by asthmatic patients. Moreover, in the adulthood comorbidities play an important role in the care management, often with reduced time to apply these clinical tools by healthcare professionals. Concluding, we believe that asthma control scores are simple and useful monitoring tools, but the most of these refer to a short previous period and are often influenced by the subjective or caregivers' symptom perception, for this reason they should be combined, when possible, with more objective tests such as pulmonary function tests or a careful clinical follow-up.
Patients as well as parents should be encouraged to keep track of symptoms consequently healthcare practitioners should adequately train them on this issue. As recognized by several guidelines, many patients can benefit from a written action plan in which, according to the disease control, the patient is instructed to recognize the need for action e. A detailed education program for both adults and pediatric patients should cover: training on treatment adherence and correct use of medication, recognition and avoidance of triggers and risk factors for exacerbations or worsening of symptoms such as exposure to allergens, influenza virus or rhinoviruses, smoke both active and passive or other environmental factors, including workplace related factors 25 , Among adults, educational programs have been repeatedly proven effective in improving symptoms control, quality of life and treatment compliance therefore they potentially can prevent or reduce severe exacerbations conducive to urgent visits and hospital admissions 4 , 5.
A recent prospective randomized controlled trial including adults with asthma showed that a single 10 min, educational session provided by a respiratory specialist, could substantially improve asthma control determined by the ACT score after 3 months. The educational program included basic information about asthma treatment and instructions on inhalation technique for about 10 min More recently, new tools for the self-assessment of asthma control are available such as applications for smartphones, often produced by respiratory societies, which can often be obtained for free 28 , These applications enable patients to enter in their profile daily data such as symptoms and their frequency, ACT, PEF values etc.
The app can therefore calculate the level of asthma control. Some apps have up to date pollen maps and calendars, or have personalized acoustic memos to remind patients to take the inhaled therapy Vasbinder et al. The study failed to prove a significant improvement in asthma control, quality of life or asthma exacerbations with high costs in the intervention group, although RTMM with tailored SMS reminders improved adherence to ICS Nevertheless, e- devices may be precious tools for monitoring, especially in adolescence.
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Teenagers, in particular, may experience age-related difficulties as they accept responsibility for self-management from their parents; the negative impacts of asthma are largely preventable if adolescents engage in self-management behaviors, including symptom prevention as treatment adherence and trigger avoidance or symptom monitoring. The availability of these new promising resources certainly opens up new possibilities in the management and monitoring of asthma, even though a recent Cochrane meta-analysis including 21 studies in adults and children , concluded that tele-healthcare for asthma did not seems to improve QoL or reduce exacerbation rate in children Therefore, further evidences and studies will be needed to routinely recommend the use of these tools in the clinical practice.
The functional hallmark of asthma is a reversible airway obstruction and its detection is often required for the diagnosis of the disease. The severity of obstruction is a known risk factor for exacerbations, therefore functional monitoring is essential in order to achieve optimal control. Moreover, severity of obstruction does not always correlate with symptoms: a significant bronchial obstruction may be present also in asymptomatic children and adults. It has been shown that children with chronic obstruction are less likely to perceive the symptom of dyspnea than children with an acute obstruction For this reason, children with poor perception of chronic obstruction are at risk of developing severe exacerbations, associated with poor lung function.
Therefore, a regular assessment of lung function is crucial. The spirometry is the main test for detecting and measuring airway obstruction in children over 5 years old and adults and it has some precision for predicting future attacks. Reference values of the lung function tests suggested by several guidelines are reported in Table 2. Table 2.
Positive test threshold of objective tests in children aged 5 years and over and adults. The presence of expiratory airflow limitation should be valued at diagnosis or at the beginning of treatment in order to evaluate increase in treatment dose , after 3—6 months of controller therapy and then periodically depending on clinical course, although SIGN and GINA guidelines do not indicate clear recommendations on monitoring FEV1 in children 5 , 6.
NICE guidelines specify to perform a spirometry for monitoring asthma at each visit or at least after 3 or 6 months from the beginning of therapy and then every 1—2 years 8. Spirometer parameters should be adjusted according to sex, age, and ethnicity. Different guidelines often diverge in the choice of this cut-off according to NICE guidelines, it is 0.
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In general, a fixed threshold might lead to an overestimation of obstruction in elderly patients and an underestimation in young ones In Table 3 we reported the main lung function tests used in our clinical setting in monitoring asthma. Table 3.
Main lung function tests used in our clinical setting in monitoring asthma. In order to compare spirometry findings in children, Global Lung Initiative recommend that the spirometry values should be expressed in z score, even though these recommendation is poorly applied worldwide 5. Some authors have argued that other indices, such as FVC, should be also considered, as some patients with severe obstruction respond to bronchodilators with a significant increase in FVC but not FEV1 In order to compare spirometry findings in children, Global Lung Initiative recommend that the spirometry values should be expressed in z score, even though these recommendation is poorly applied worldwide 8.
The assessment of bronchodilator reversibility BDR can be useful not only to confirm the diagnosis but also in the asthma monitoring. In severe pediatric asthma, the spirometry should be always performed with a bronchodilator test to detect airway obstruction and its reversibility since it has been shown that these children have an increased bronchodilator response that may be associated with higher risk of impairment of lung function 42 , A persistent BDR may also be associated with poor therapy compliance or wrong inhaler technique and seems to correlate to some indices of airway inflammation, such as the exhaled nitric oxide fraction FeNO , therefore it might be predictive for a positive response to inhaled corticosteroids ICSs Regarding the most appropriate setting to perform lung function tests, although spirometry performed in the primary care setting may be a useful tool in asthma monitoring, concerns have been raised about the quality and standardization of this procedure compared to hospital-based or laboratory spirometry.
The spirometry provides objective data of lung function, but the outcome is often dependent on the operator. Therefore, in our opinion, expert personnel that spurs the patient to an optimal execution should perform it. Home monitoring of peak expiratory flow PEF may be use as an additional functional test in the monitoring of asthma. There is still lack of evidence that PEF monitoring over time might result in better disease control. PEF measurement can be used to document the variability of bronchial obstruction in asthma even if PEF is not related to FEV1 values and may underestimate the degree of airflow limitation and air trapping.
Moreover, PEF values vary depending on the meter used therefore it is advisable to compare its measurement with the best personal value obtained during the disease control phase or during maximum treatment using the same meter. According with most of the guidelines, PEF measurement should not be routinely used to monitor asthma in children, unlike in adults where it is recommended for subjects with severe asthma or with poor perception of airflow limitation 5 , 6 , 8. Certainly, PEF measurements do not give information about the obstruction characteristics obstructive or restrictive or site.
The ease of execution even in pediatric age and the possibility of being performed at home and during acute phase make this test easy to handle and reproducible, even though its monitoring does not improve asthma control in addition to clinical scores in adults and children 6 , For this reason, PEF assessment is not recommended in pediatric age in asthma monitoring.
During childhood, impulse oscillometry IOS and the technique of forced oscillations FOT may be used as an alternative technique to assess lung function, since measurements are made from tidal breathing and younger children are able to comply compared to spirometry. IOS measures respiratory resistance and reactance by analyzing responses to pressure waves of different frequency. The assessment of airflow resistance can be an indirect indicator of airway caliber, while spirometry mainly reflects airflow characteristics.
IOS is easily performed during tidal breathing therefore it only need a partial collaboration of small patients, even though it is not available in all centers and in some cases, it is difficult to interpret. Several studies showed a significant association between findings of the IOS and those of spirometry. In asthma, IOS has been used to assess the bronchodilator response and the therapeutic response to different treatments.
In studies utilizing both IOS and spirometry, the first one has proved to be more useful than spirometry in early detection of asthmatic children from normal cohorts Many evidence showed that peripheral airways PAW in children as in adults are the initial site of inflammation and obstruction in asthmatic disease IOS can evaluate peripheral airways more accurately than spirometry identifying a PAW impairment before symptoms and spirometric abnormalities occur. For these reasons, it could be used to guide an early therapeutic approach to prevent clinical symptoms and further lung damage In adulthood, excluding patients with severe chronic asthma and marked airway obstruction, an expiratory flow limitation ELF at rest is seldom observed, unless under severe and prolonged bronchoconstriction.
When the oscillatory pressure applied at the mouth does not reach alveoli during expiration due to a flow-limiting segment in the bronchial tree, the reactance signal, instead of reflecting the mechanical properties of the lung parenchyma and airways, is influenced only by those of the airways and becomes much more negative with a clear distinction between inspiration and expiration. This application of the FOT is useful to identify flow limitation during tidal breathing, but the closure of intrathoracic airways eventually occurring at end expiratory lung volume EELV must be considered as an important limiting factor of this technique, since the distortion of the reactance signal is similar 52 , In addition, when EFL originates in the peripheral airways, it is mainly due to the viscous, density-independent, flow-limiting mechanism, while the speed wave, density-dependent, flow-limiting mechanism is substantially involved when the EFL originates in the central airways.
Despite several potential applications of FOT and oscillometry, larger longitudinal studies will be needed to confirm the usefulness of these techniques as routinely monitoring tools in asthma. The ideal tool for this purpose is represented by the cell count on BAL during bronchoscopy. The invasive nature of the procedure has obviously limited the number of subjects studied, therefore the scientific community has sought surrogates that allowed the identification of different asthma phenotypes such as eosinophils count in induced sputum and the peripheral eosinophilia.
Based on the sputum analysis, patients with asthma can be grouped in four different inflammatory phenotypes: eosinophilic asthma, neutrophilic asthma, mixed granulocytic asthma, and paucigranulocytic asthma.
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Several studies have found higher levels of sputum eosinophils in uncontrolled asthmatics, therefore sputum analysis may be a useful method of objectively monitoring asthma Moreover, the short-term response to inhaled corticosteroids depends on the amount of eosinophils present in the sputum therefore this technique may be a guide for modulating steroid therapy A recent study by Fleming et al. It is difficult for children to collect sputum because they tend to swallow more than expectorate. Among pediatric patients with bronchial hyperactivity, induced sputum, through stimulation with hypertonic saline, may allow to understand the type of inflammation, the presence of cells and lower respiratory tract mediators 59 — In clinical practice, the use of these tools for the diagnosis and monitoring of asthma certainly has limitations, however among pulmonologists and also in our center these may be a precious help for the assessment of the type of inflammation, the diagnostic confirmation and the adjustment of the preventive therapy.
High eosinophil count in peripheral blood is a recognized risk factor for disease severity and for future exacerbations 58 , During childhood, the asthma predictive index API also include blood eosinophils within minor criteria as predictor of future recurrent wheezing 65 , Nadif et al. For these reasons, the bronchial and peripheral eosinophilia could be considered a potentially useful biomarker for the selection of patients who will respond to anti IL5 therapy, a monoclonal antibody used in patient older than 12 years with refractory eosinophilic asthma.
As already mentioned, the detection of different asthma phenotypes guided the scientific community searching for specific biomarkers that could guide and improve the disease monitoring and the therapeutic approach. The monitoring of asthma should also include the determination of minimally invasive inflammatory markers. Fractional exhaled nitric oxide FeNO measurement correlates with eosinophilic airway inflammation and therefore with the most common asthma endotype, independently of gender, and age. FeNO levels are higher in asthmatic children compared to non-asthmatic children and in one study values rose further during exacerbations and rapid decline after oral steroid treatment 68 — Agency for Healthcare Research and Quality AHRQ , recently conducted a systematic review including studies about the role of FeNO in the diagnosis, treatment and monitoring of asthma.
Both in adults and in children FeNO results can predict which patients will respond to inhaled corticosteroid therapy, therefore the use of this marker in long-term managing of treatments can reduce the frequency of exacerbations. Nevertheless, regarding the asthma monitoring in preschooler children authors concluded that there is insufficient evidence supporting the use of FeNO in this category for predicting a future diagnosis of asthma Two recent Cochrane reviews, including both pediatric and adulthood studies, showed that tailoring asthma medications based on FeNO levels decreased the frequency of asthma exacerbations but did not impact on day-to-day clinical symptoms or inhaled corticosteroid dose 71 — In conclusion, FeNO role in asthma management has not been concretely proven due to incomplete evidence therefore it is not routinely recommended in all patients, at least in monitoring, even though it may be useful in subjects who respond poorly to inhaled corticosteroids Nevertheless, the use of biomarkers as tools for phenotyping asthma and personalizing therapy is certainly attractive but it has not yet entered clinical practice.
A hallmark feature of asthma is increased responsiveness of the airways to inhaled stimuli. The assessment of bronchial responsiveness through provocation tests can be useful for both research purposes and clinical practice. Monitoring of bronchial hyper-responsiveness BHR is not routinely recommended in current guidelines, since its role is more typically confined to the diagnostic process. However, some data seem to indicate a potential usefulness of BHR among asthmatic adults, as an indicator of exacerbation risk and inhaled corticosteroid response 75 , Bronchial provocations tests are not usually performed in asthmatic children and several papers support this recommendation including one clinical trial Nevertheless, BHR assessments could have a role in asthma monitoring among children with exercise limitations or with reduced perception of symptoms Within the pediatric population, the exercise test may be a precious tool for the evaluation of indirect BHR A reduction in post-exercise FEV1 compared to the baseline is considered a sign of bronchial obstruction induced by exercise.
Both for adults and children, the detection of potentially modifiable risk factors for exacerbations may be useful in asthma monitoring and includes the exposure to specific allergens, smoking, high SABA use, poor adherence to therapy and incorrect inhaler technique. As already mentioned, GINA guidelines state that a previous sever exacerbation in last 12 months and a history of access into an intensive care or intubation are major independent risk factors for exacerbations 5.
Moreover, the asthma monitoring cannot be separated from an early identification and management of associated comorbidities Table 4. Comorbidities are obviously more frequent in adults and may significantly complicate the management of asthma throughout all its stages, from diagnosis to treatment. All guidelines present this point as relevant in the workup of asthma. The most frequent comorbidities among adult population include upper airway diseases rhinitis, chronic rhinosinusitis , obesity, COPD, gastro-esophageal reflux disease GERD , bronchiectasis; in elderly patients, heart failure is very common.
From an epidemiological point of view, rhinitis, and rhinosinusitis are the most frequent comorbidities of asthma for all ages and the former seems to be associated with an increased risk of exacerbations The presence of GERD is associated with worse asthma symptoms and poorer quality of life while obesity can worsen asthma by compromising lung function, inducing corticosteroid insensitivity and systemic inflammation 81 — All these conditions often exacerbate or simulate symptoms of asthma causing a poor response to treatment.
For these reasons, it is essential to assess and carefully monitor these comorbidities also by implementing integrated care pathways. Other conditions that may present with elevated blood eosinophilia and a clinical picture mimicking a severe refractory asthma, such as chronic eosinophilic pneumonia, Churg-Strauss syndrome, allergic bronchopulmonary aspergillosis ABPA , should be taken into account during asthma monitoring Finally, a subset of adult patients usually over 40 years of age present a combination of both asthma and COPD features which is known as Asthma-COPD overlap syndrome ACOS , likely resulting from different phenotypes of airway disease.
Interpretation of Pulmonary Function Tests: A Practical Guide by Robert E. Hyatt
They are often smokers, but may have allergies and a family or personal history of asthma with a not completely reversible airway obstruction 5. Additional diagnostic findings include eosinophilic airway inflammation, a good response to corticosteroid therapy, and high concentrations of exhaled nitric oxide, which should be assessed in the monitoring of these patients Since ACOS outcome is generally worse than asthma with higher treatment needs, the management should be especially careful therefore it might be advisable to refer these patients to specialized center.
Each asthmatic patient is different, so each action plan will be too. The asthma action plan should be based on symptoms trend or peak expiratory flow PEF measurements and is individualized according to the pattern of the patient's disease. In children, symptom-based plans are preferred.
Inclusion of PEF measurements in the asthma action plan can be beneficial for adults with more severe or difficult-to-control asthma and those with poor symptoms perception.