Rapid maxillary expansion and nasal patency in mouth breathing children with maxillary atresia due to or not due to allergic rhinitis.

AIM: To evaluate the effects of rapid maxillary expansion (RME) on nasal patency in mouth breathing (MB) children with maxillary atresia due to or not due to allergic rhinitis (AR) associated with asthma. METHODS: Fifty-three MB children/adolescents (aged 7-14 years) with mixed or permanent dentition and maxillary atresia participated, with or without unilateral or bilateral crossbite. They formed the groups: RAD (AR + asthma; clinical treatment, RME); RAC (AR + asthma; clinical treatment, no RME); and D (mouth breathers; RME only). RAD and RAC patients received topical nasal corticosteroid and/or systemic H1 antihistamine (continuous use) and environmental exposure control. All were evaluated before RME (T1) and 6 months after (T2) with the CARATkids score, acoustic rhinometry, and nasal cavity computed tomography (CT). Patients RAD and D underwent RME (Hyrax® orthopedic appliance). RESULTS: A significant reduction in the CARATkids score occurred in the RAD (-4.06; p < 0.05), similarly when patient and parent/guardian scores were evaluated (-3.28 and -3.16, respectively). Acoustic rhinometry (V5) showed increased nasal volume in all groups, significantly higher in RAD patients than in RAC and D (0.99 × 0.71 × 0.69 cm3, respectively). CT of the nasal cavity documented increased volume in all three groups, with no significant differences between them. CONCLUSION: In MB patients with AR, asthma, and maxillary atresia, RME increased nasal cavity volume and improved respiratory symptoms. However, it should not be used as the only treatment for managing patients with respiratory allergies.

Local allergic rhinitis in children: A systematic review.

BACKGROUND: Local allergic rhinitis (LAR) is a well-defined and reported phenotype in adults, but data is scarce for children and adolescents, and it is probably an undiagnosed and highly underestimated condition in childhood. OBJECTIVES: The objectives of this systematic review were to identify original observational studies published on LAR in children and adolescents and to describe the prevalence and characteristics of this phenotype in the pediatric age group. METHODS: A systematic search was performed in PubMed and EMBASE databases. The search was limited to publications on humans, written in English, published between January 1, 2000 and September 20, 2021. Participants had to be under 18 years old and with a diagnosis of LAR confirmed by nasal allergen provocation test (NAPT). RESULTS: Ten articles were identified. Despite the wide variability of protocols, prevalence rates ranged from 3.7 to 83.3% among children previously diagnosed as having nonallergic rhinitis, being markedly lower in Eastern countries (3.7-16.6%) when compared to Western countries (22.3-83.3%). To date, no relevant clinical characteristics capable of differentiating LAR patients from other childhood rhinitis phenotypes have been identified. CONCLUSIONS: LAR is an allergic rhinitis phenotype also found in children. Population and regional differences and differences in NAPT protocols may explain the heterogeneity in LAR prevalence rates observed in different parts of the world. In addition to clarifying this large discrepancy, longitudinal studies are also needed to assess the clinical characteristics of the LAR phenotype in the pediatric age group, and its stability into adulthood must be confirmed.

Impulse oscillometry in children and adolescents with persistent asthma and its correlation with spirometry.

INTRODUCTION: Asthma is one of the most common chronic diseases of childhood. Spirometry is the traditional test for assessing lung function, while impulse oscillometrics is an alternative resource that measures the impedance of the respiratory system. OBJECTIVE: : To evaluate the pulmonary function of children and adolescents with asthma by impulse oscillometry and correlate the findings with those obtained by spirometry. METHODS: A cross-sectional study in which the pulmonary function of asthmatic children and adolescents aged between 6 and 18 years was evaluated, categorized by the level of disease control according to the Asthma Control Test (ACT) or Children Asthma Control Test (C-ACT) into controlled (ACT/C-ACT>19; n = 70) and uncontrolled (ACT/C-ACT ≤ 19; n = 60). RESULTS: A total of 130 asthmatic children and adolescents were evaluated (51% were males). There were no significant differences in the parameter values of both tests when patients were divided by the level of asthma control. Altered impulse oscillometry and spirometry were performed in 20 and 25% of the cases, respectively. Changes in impulse oscillometry were more frequent in patients with controlled asthma. R5 (%), X5 (%), and Fres showed moderate correlation with the main spirometric parameters, being stronger between X5 (%) and FEV1/FVC (%) (r: -0,58; P < 0,05) in patients with controlled asthma. Bronchodilator response was observed in a similar number of patients in both exams, but with reasonable agreement. CONCLUSIONS: Impulse oscillometry values showed a weak or moderate correlation with spirometry values.

Psychological stress in asthma: repercussions on epigenetics-genetics, immune responses, and pulmonary function in the pediatric population.

In the assessment of childhood asthma, identifying the risk factors associated with exacerbations and broadening this view to understand psychological stress and its repercussions on the inflammatory process of asthma allow a different perspective on this biopsychosocial disease. Psychological stress, as a risk factor for the onset and noncontrol of asthma, has been increasingly evaluated from the perspective of the repercussions on the body of the stimulus generated in the hypothalamic-pituitary axis and adrenal glands, with cortisol release and immune system action. These processes trigger changes in T helper 2 cells, which polarize allergic processes, and dysfunctions in immune tolerance mechanisms, with a decrease in regulatory T cells. Genetic and epigenetic changes in ß2-adrenergic and glucocorticoid receptors, with decreased response to these drugs, were also identified in studies, in addition to changes in respiratory function patterns, with worsening of obstruction and inflammation identified via decreased forced expiratory volume in one second and increased exhaled inflammatory gases in allergic asthma. Therefore, the present review sought to identify studies on the effect of personal and parental acute or chronic psychological stress, emphasizing the repercussions on genetics, epigenetics, and immune and pulmonary functional and inflammatory responses in the pediatric population.

Heart rate recovery in asthmastic children and adolescents after clinical field test.

BACKGROUND: Inflammation caused by chronic lung disease in childhood may lead to delayed heart rate recovery (HRR) however, there is lack of evidence on HRR in this population. The aim was to assess HRR after functional capacity testing in asthmatic children and adolescents and to compare with severity and disease control. METHOD: This was a study secondary to a randomized control trial. The modified shuttle test (MST) was performed to assess functional capacity and HRR. This is an externally cadenced test in which the distance walked is the outcome. HRR was assessed after MST and was defined as HR at exercise peak minus HR in the second minute after the end of exercise. Asthma control was assessed by the Asthma Control Test (ACT). Data normality was tested by Shapiro Wilk and the comparison between groups was made by Student's t test or Mann Whitney test for numerical variables, and by Chi-square test for categorical variables. Statistical significance was considered when p < 0.05. SPSS version 20 was used in the analyzes. RESULTS: The sample included 77 patients diagnosed with asthma (asthma group - AG) who were regularly treated for asthma. Control group (CG) consisted of 44 volunteers considered healthy, matched in age and gender to AG. The median age of CG was 12 (10-14) years and in AG 11 (9-13 years) being classified as mild to moderate asthmatic, and 57% of the sample had controlled asthma by ACT. Distance walked in the CG was 952 ± 286 m and AG 799 ± 313 m, p = 0.001. HRR was more efficient in CG (79 ± 15 bpm) compared to AG (69 ± 12 bpm), p = 0.001. The mild (69 ± 12 beats) and severe (72 ± 15 beats) AG presented worse HRR compared to control group (79 ± 15 bpm), p < 0.05. CONCLUSIONS: Asthmatic children and adolescents have delayed HRR after modified Shuttle test compared to their peers, suggesting that asthma leads to autonomic nervous system imbalance. TRIAL REGISTRATION: Registered in Clinical Trials under number NCT02383069 and approved by the Universidade Nove de Julho - UNINOVE Research Ethics Committee, protocol number 738192/2014.

Asthma, allergic sensitization and lung function in sickle cell disease.

BACKGROUND: Pulmonary disease is a frequent acute and chronic manifestation in sickle cell disease (SCD), presenting high morbidity and mortality. OBJECTIVES: To identify the prevalence and association of asthma, allergic sensitization and altered pulmonary function in patients with SCD (SS and Sßo). METHODS: A single-center, cross-sectional study was conducted, in which 70 patients with SCD and 44 controls, aged six to 18 years, responded to the questionnaire of the International Study of Asthma and Allergies in Childhood (ISAAC), complemented with an anamnesis regarding the associated clinical outcomes. All patients underwent immediate hypersensitivity skin tests with aeroallergens and a pulmonary function evaluation (spirometry). Regarding the statistical analysis, parametric and non-parametric methods were used, depending on the variables studied. Tests were considered significant when p<0.05. RESULTS: There was no significant difference between the patients and controls regarding the prevalence of asthma and allergic sensitization (p>0.05). The number of occurrences of acute chest syndrome per patient per year was significantly higher for asthmatic patients than for non-asthmatic patients (p=0.04). Obstructive pulmonary function occurred in 30.9% of the patients and in 5.4% of the controls, and restrictive pulmonary function occurred in 5.5% of the patients and 5.4% of the controls. Asthma and wheezing in the last 12months had significant associations with obstructive pulmonary function (p=0.014 and p=0.027, respectively). CONCLUSIONS: The occurrence of asthma, allergic sensitization and alteration in lung function in patients with SCD reinforces the importance of routine monitoring of these diagnoses, which allows for early treatment and prevention of the evolution of pulmonary disease in adulthood.

Lung Function in Infants with Sickle Cell Anemia.

Lung volumes and forced expiratory flows were evaluated in 22 infants with sickle cell anemia and compared with a control group. Forced expiratory flows showed significantly lower values in the sickle cell group. The majority of infants had normal lung function, and obstruction was the most common pattern of abnormality.

Control of Allergic Rhinitis and Asthma Test for Children (CARATKids): Validation in Brazil and cutoff values.

BACKGROUND: The Control of Allergic Rhinitis and Asthma Test for Children (CARATKids) assesses asthma and allergic rhinitis control in children younger than 12 years. OBJECTIVE: To validate the Brazilian Portuguese version of the CARATKids and to define the cutoff values for identifying uncontrolled disease. METHODS: Children aged 6 to 12 years with asthma and allergic rhinitis were studied (n = 102). CARATKids, childhood Asthma Control Test (cACT), total nasal symptom score (TNSS), and visual analog scale (VAS) scores were obtained at baseline and after 4 to 6 weeks. Internal consistency, test-retest reliability, responsiveness, and validity of the Brazilian CARATKids were assessed according to the Consensus-based Standards for the Selection of Health Measurements Instruments checklist. The minimal clinically important difference (MCID) was evaluated using distribution and anchor methods. Spearman correlations were used to compare CARATKids scores with external measures of control. Receiver operating characteristic curve analysis was performed to establish cutoff values. RESULTS: Fifty children completed both visits. The Cronbach α and intraclass correlation coefficient of CARATKids were 0.81 and 0.85, respectively. The Guyatt responsiveness index was -1.34, and within-patient change in clinically unstable patients (n = 31) was significant (P = .02). As for cross-sectional and longitudinal validity, correlation coefficients ranged from 0.58 to 0.77 (P < .001) and 0.30 to 0.57 (P < .05), respectively. The estimated MCID for CARATKids was 3. The optimal cutoffs (sensitivity and specificity) to exclude uncontrolled and controlled disease were 3 or less (97% and 67%) and 6 or greater (56% and 96%), respectively. CONCLUSION: CARATKids is a reliable and valid tool to assess asthma and allergic rhinitis control in Brazilian children. A score of 6 or higher on CARATKids identifies uncontrolled disease, and a score of 3 or lower excludes poor disease control.

Quality of life of asthmatic children and adolescents: Portuguese translation, adaptation, and validation of the questionnaire "Pediatric Quality of Life (PedsQL) Asthma Module".

OBJECTIVE: The objectives of the study were to translate, validate, and verify the psychometric properties of the Portuguese version of the instrument "Pediatric Quality of Life Asthma Module" (PedsQL Asthma) culturally adapted for the Brazilian culture. METHODS: After being translated to Portuguese and being culturally adapted, the questionnaire was answered by 200 asthmatic children and adolescents (aged 2-18) as well as the adults responsible for them. Validation required the use of the following instruments: PedsQL Asthma Children (applied to children and adolescents), PedsQL Asthma Parents (applied to adults responsible for children and adolescents), Pediatric Asthma Quality of Life (PAQLQ), Asthma Control Test (ACT) or Childhood Asthma Control Test (C-ACT), as well as socioeconomic and personal information questionnaires. A group of 45 clinically stable children repeated the questionnaires 15-60 days after answering the first questionnaire. RESULTS: Correlations between the scores of PedsQL Children and PedsQL Parents (r  =  0.67), PedsQL Children and PAQLQ (r  =  0.66), and PedsQL Parents and PAQLQ (r  =  0.64) were moderate and significant. Correlations were higher for men (r  =  0.72) when analyzing the children's and parents' answers to PedsQL according to gender. The 5- to 7-year-old age group had the strongest correlations with PAQLQ (r  =  0.79). Cronbach's alpha coefficient for PedsQL Children and Parents had values of 0.85 and 0.87, respectively. A high concordance was observed in both tests at different times, with kappa values of 0.89 and 0.87 for PedsQL Children and Parents, respectively. CONCLUSION: The instrument used in this study was considered valid, consistent, and reproducible and has acceptable psychometric properties for the Brazilian population.

Is allergen immunotherapy a model of personalized treatment in pediatric respiratory allergy?

PURPOSE OF REVIEW: To review recent evidence on allergen immunotherapy (AIT) as a model of personalized medicine in the treatment of children and adolescents with respiratory allergies. RECENT FINDINGS: Meta-analysis and systematic review studies continue to point out that AIT is an effective treatment for children with respiratory allergies. Molecular allergy allows the understanding of patient sensitization profiles that frequently change the prescription of AIT. There is still a lack of evidence showing that this personalized prescription of AIT is associated with better clinical outcomes. The nasal allergen challenge has extended the indications of AIT for a new group of subjects with local allergic rhinitis. Patient selection of allergens involved in the increasingly personalized composition of extracts to be used in AIT increasingly characterizes it as personalized medicine. SUMMARY: Despite the numerous studies carried out to identify the best biomarker to evaluate the response to AIT, there is still much disagreement, and clinical assessment (symptoms, quality of life, among others) continues to be the best way to evaluate the therapeutic success of AIT.

Behavioral disorders in children and adolescents with atopic dermatitis.

OBJECTIVES: To assess the prevalence and pattern of behavioral problems in children and adolescents with atopic dermatitis (AD) and to study their associations with clinical data and severity. METHODS: This was a single-center, cross-sectional study of patients (6-17 years) with AD. Assessment of competencies and syndrome scale scores of behavioral problems was performed by applying the Child Behavior Checklist 6-18 (CBCL 6-18) and AD severity using the Eczema Area Severity Index (EASI) score. RESULTS: Of the 100 patients with AD, 56% were male, with a mean age of 11±3 years, and 43% had moderate/severe AD. Borderline or abnormal values were found in 75% of the patients for total social competence, 57% for internalization, 27% for externalization, and 18% for aggressive behavior. A higher prevalence of aggressive behavior (27.9% vs. 10.5%; p = 0.02) and sleep disorders (32.6% vs. 15.8%; p = 0.04) was observed in patients with moderate/severe AD than in those with mild AD. Children with current or previous use of immunosuppressants/immunobiological tests had a lower frequency of normal social competence (53% vs. 83%, p = 0.012). Regarding the critical questions, 8% responded affirmatively to suicidal ideation. CONCLUSION: A high prevalence of behavioral problems was observed among children and adolescents with AD, with a predominance of internalizing profiles, mainly anxiety and depression. Children with moderate/severe AD have a higher prevalence of aggressive behaviors and sleep disorders. These findings highlight the importance of multidisciplinary teams, including mental health professionals, in caring for patients with AD.

V Brazilian Consensus on Rhinitis - 2024.

Since we published the "IV Brazilian Consensus on Rhinitis", in2017, several advances have been achieved and have enabled a further understanding of the different aspects of "Rhinitis". This new guideline, developed jointly by ASBAI, SBP and SBORL, represents a relevant milestone in the updated and integrated management of the different forms of the disease, and it aims to unify evidence-based approaches to improve the diagnosis and treatment of this common and often underestimated condition. The document covers a wide range of topics, including clear definitions of the different phenotypes and endotypes of rhinitis, risk factors, updated diagnostic criteria, and recommended methods for clinical and laboratory investigation. We stress the importance of detailed clinical history and objective assessment, as well as tools for control and assessing severity tools an accurate diagnostic approach to the disease. Regarding treatment, it emphasizes the treatment customization, considering the severity of symptoms, the presence of comorbidities and the impact on the patient's quality of life. We discuss different drug treatment, in addition to non-pharmacological measures, such as environmental control and specific immunotherapy; and the possible role of immunobiological agents. Furthermore, the consensus addresses issues related to patient education, prevention and management of special situations, such as rhinitis in children, in pregnant women and in the elderly. In short, the "V Brazilian Consensus on Rhinitis" represents a comprehensive and updated guide for healthcare professionals involved in the diagnosis and management of rhinitis, aiming to improve patients' quality of life through an integrated and evidence-based approach.

Pediatric allergy and immunology in Brazil.

The subspecialty of pediatric allergy and immunology in Brazil is in its early years and progressing steadily. This review highlights the research developed in the past years aiming to show the characteristics of allergic and immunologic diseases in this vast country. Epidemiologic studies demonstrated the high prevalence of asthma in infants, children, and adolescents. Mortality rates and average annual variation of asthma hospitalization have reduced in all pediatric age groups. Indoor aeroallergen exposure is excessively high and contributes to the high rates of allergy sensitization. Prevalence of food allergy has increased to epidemic levels. Foods (35%), insect stings (30%), and drugs (23%) are the main etiological agents of anaphylaxis in children and adolescents. Molecular diagnosis of primary immunodeficiencies (PID) showed a high incidence of fungal infections including paracoccidioidomycosis in X-linked hyper-IgM syndrome, and the occurrence of BCG adverse reactions or other mycobacterial infections in patients with chronic granulomatous disease. Education in pediatric allergy and immunology is deficient for medical students, but residency programs are effective in training internists and pediatricians for the practice of allergy. The field of PID requires further training. Last, this review is a tribute to Prof. Dr. Charles Naspitz, one of the pioneers of our specialty in Brazil.

Risk factors for wheezing disorders in infants in the first year of life living in São Paulo, Brazil.

The objective of this study was to identify risk factors for wheezing disorders in the first year of life in infants living in São Paulo (SP), Brazil, applying the standardized protocol of the Estudio Internacional de sibilancia en lactentes-Phase 1. A total of 1014 parents or caregivers of infants, who attended for routine evaluation and immunization in public health centers were interviewed in Southern SP city. Risk factors significantly associated with recurrent wheezing were: history of previous pneumonia, daycare attendance, consumption of processed food, presence of a cat at home, more than five upper respiratory infection (URI) episodes and the first URI before the age of sixth month. Most of these risk factors for wheezing can be avoided or controlled. Prospective studies on wheezing, especially in children with a severe presentation, are needed to analyze the impact of these risk factors and the effect of preventive actions.

Incidence, triggering factors, symptoms, and treatment of anaphylaxis in a pediatric hospital.

Objective: Assess the incidence of anaphylaxis in the emergency room (ER) of a private pediatric hospital in the city of São Paulo, Brazil, and describe associated factors. Method: This was a cross-sectional, retrospective, and observational study based on the medical records of patients from 0 to 18 years old seen at the emergency unit during the years of 2016-2019, who had a diagnosis potentially related to anaphylaxis according to ICD-10. All medical records were individually reviewed for the presence of compatible signs and symptoms that identified "possible" cases of anaphylaxis. Cases were considered probable anaphylaxis when medical history was compatible and indicative of anaphylaxis in the opinion of at least 2 allergists. Results: The incidence of anaphylaxis was 0.013%. Among the 56 patients identified (mean age 4.2 years), food was the most predominant suspected factor (53%), followed by unknown factors (32%), and drugs (12.5%). All patients presented with cutaneous symptoms, 74% with respiratory, and 53% with gastrointestinal. Allergic disease as a comorbidity was found in 39% of the children and 11% had a history of previous anaphylaxis. There were neither cases of syncope or shock, nor deaths. Intramuscular (IM) adrenaline was prescribed in 37.5% of cases. Conclusions: The incidence of anaphylaxis was low when compared to the worldwide incidence. The severity of most cases was mild, cutaneous symptoms were predominant, and food was the suspected trigger most frequently associated with reactions.

Mucopolysaccharidosis patients have reduced functional capacity.

INTRODUCTION: Mucopolysaccharidoses (MPSs) are a group of rare diseases caused by an intralysosomal accumulation of glycosaminoglycans, resulting in a multisystemic clinical condition characterized by variable degrees of physical-functional impairment. OBJECTIVE: To evaluate the functional capacity (FC) of MPS patients and compare with a healthy control group. METHODS: This is a cross-sectional study of 6- to 39-year-old patients followed at a medical reference center and compared with their control peers, matched by age and sex. FC was assessed using the Sit-to-Stand Test (SST) and Incremental Shuttle Walk Test (ISWT). Heart rate (HR) and Borg rating of perceived exertion were measured before and after ISWT. HR recovery (HRR) was defined as the HR at the end of the test minus the HR in the second minute after ISWT. RESULTS: Nineteen (19) MPS patients, 69% with type II MPS and mean age 17 ± 11 years were evaluated. Every patient was under enzyme replacement therapy. The time to perform the SST was longer in the MPS group (10.6 ± 2.5 s vs. 6.7 ± 1.2 s; p < .01). The MPS group achieved lower values of distance covered on the ISWT (407.6 ± 329.8 m vs. 1131.9 ± 183.3 m; p < .01), with a significantly higher Borg (6 [5-8] vs. 2 [1-4]; p = .02). The MPS group's HRR was slower than the controls (32.9 ± 20.2 beats per minute [bpm] vs. 69.1 ± 25.9 bpm; p < .001). DISCUSSION: We observed a pronounced reduction in the MPS group's FC compared to their healthy peers and a worse HRR after completing the test.

Is the modified shuttle test a maximal effort test in children and adolescents with asthma?

PURPOSE: Whether the modified shuttle test (MST) achieves maximal effort in children and adolescents with asthma is unclear. The aim was to compare the physiological responses of MST to the cardiopulmonary exercise test (CPET) in pediatric patients with asthma, to observe its convergent validity. PATIENTS AND METHODS: A cross-sectional study with volunteers with asthma (6-17 years of age) under regular treatment. The MST is an external-paced test, and the participants were allowed to walk/run. CPET was performed on a cycle ergometer to compare with MST. Gas exchange (VO2 , VCO2 , and VE) and heart rate (HR) were the outcomes and were continuously assessed in both tests. RESULTS: Forty-seven volunteers were included, normal lung function expiratory forced volume at 1st second/forced vital capacity (FEV1 /FVC) 88.6 (7.7). VO2peak was higher at MST (2.0 ± 0.6 L/min) compared to CPET (1.6 ± 0.5 L/min), p < 0.001. Similar results was observed to VE at MST (50 ± 16 L/min) versus VE at CPET (40 ± 13 L/min), and to VCO2 at MST (2.1 ± 0.8 L/min) versus VCO2 at CPET (1.7 ± 0.6 L/min), p < 0.001. HR was also higher at MST (94 ± 6%pred) versus CPET (87 ± 8%pred), p = 0.002. VO2peak in MST correlated to the CPET (r = 0.78, p < 0.001). The ICC of VO2peak between tests was 0.73 (0.06-0.89), p < 0.001, and VO2peak Bland-Altman analysis showed a bias of 0.46 L/min. CONCLUSION: The MST showed a maximal physiologic response in children and adolescents with asthma. It is a valid test and can be used as an alternative to evaluating exercise capacity.

Prolonged slow expiration technique in infants: effects on tidal volume, peak expiratory flow, and expiratory reserve volume.

BACKGROUND: Prolonged slow expiration (PSE) is a physiotherapy technique often applied in infants to reduce pulmonary obstruction and clear secretions, but there have been few studies of PSE's effects on the respiratory system. OBJECTIVE: To describe PSE's effects on respiratory mechanics in infants. METHODS: We conducted a cross-sectional study with 18 infants who had histories of recurrent wheezing. The infants were sedated for lung-function testing, which was followed by PSE. The PSE consisted of 3 sequences of prolonged manual thoraco-abdominal compressions during the expiratory phase. We measured peak expiratory flow (PEF), tidal volume (V(T)), and the frequency of sighs during and immediately after PSE. We described the exhaled volume during PSE as a fraction of expiratory reserve volume (%ERV). We quantified ERV with the raised-volume rapid-thoracic-compression technique. RESULTS: The cohort's mean age was 32.2 weeks, and they had an average of 4.8 previous wheezing episodes. During PSE there was significant V(T) reduction (80 ± 17 mL vs 49 ± 11 mL, P < .001), no significant change in PEF (149 ± 32 mL/s vs 150 ± 32 mL/s, P = .54), and more frequent sighs (40% vs 5%, P = .03), compared to immediately after PSE. The exhaled volume increased in each PSE sequence (32 ± 18% of ERV, 41 ± 24% of ERV, and 53 ± 20% of ERV, P = .03). CONCLUSIONS: It was possible to confirm and quantify that PSE deflates the lung to ERV. PSE caused no changes in PEF, induced sigh breaths, and decreased V(T), which is probably the main mechanical feature for mucus clearance.