Infant Pulmonary Function Testing Research Articles

Clinical prediction rule to diagnose post‐infectious bronchiolitis obliterans in children

Infant pulmonary function testing has a great value in the diagnosis of post-infectious bronchiolitis obliterans (BOs), because of characteristic patterns of severe and fixed airway obstruction. Unfortunately, infant pulmonary function testing is not available in most pediatric pulmonary centers. To develop and validate a clinical prediction rule (BO-Score) to diagnose children under 2 years of age with BOs, using multiple objectively measured parameters readily available in most medical centers. Study subjects, children under 2 years old with a chronic pulmonary disease assisted at R. Gutierrez Children's Hospital of Buenos Aires. Patients were randomly divided into a derivation (66%) and a validation (34%) set. ROC analyses and multivariable logistic regression included significant clinical, radiological, and laboratory predictors. The main outcome measure was a diagnosis of BOs. The performance of the BO-Score was tested on the validation set. Hundred twenty-five patients were included, 83 in the derivation set and 42 in the validation set. The BO-Score (area under ROC curve = 0.96; 95% CI, 0.9-1.0%) was developed by assigning points to the following variables: typical clinical history (four points), adenovirus infection (three points), and high-resolution computed tomography with mosaic perfusion (four points). A Score > or =7 predicted the diagnosis of BOs with a specificity of 100% (95% CI, 79-100%) and a sensitivity of 67% (95% CI, 47-80%). The BO-Score is a simple-to-use clinical prediction rule, based on variables that are readily available. A BO-Score of 7 or more predicts a diagnosis of post-infectious BOs with high accuracy.

Longitudinal assessment of lung function from infancy to childhood in patients with cystic fibrosis

Infant pulmonary function testing (IPFT) has become an important clinical tool for the evaluation of lung function in infants with Cystic Fibrosis (CF); however, it is still unclear whether lung function in infancy is predictive of lung function later in life. We hypothesized that measures of airflow obstruction by IPFT would correlate strongly with lung function by conventional spirometry later in childhood. A retrospective analysis was performed of all CF infants studied with IPFT at the University of Minnesota Children's Hospital between September 1994 and March 2003. A total of 41 patients underwent IPFT and had valid spirometry results available at age 6 or later. IPFT values, such as I:E ratio, respiratory rate, tidal volume, and T(ptef)/T(e), were calculated from tidal breathing loops. Passive respiratory system mechanics, which included C(rs), R(rs), and tau(rs), were measured by the single breath end-inspiratory occlusion technique. Forced expiratory flows, including V(max)FRC, FVC, FEF(50), and FEF(75), were obtained by rapid thoracic compression and included a full vital capacity maneuver by the multiple inflation method. FRC measurements were calculated from data obtained via nitrogen washout in a subset of patients. In addition, information on age at diagnosis and results of oropharyngeal (OP) cultures at diagnosis and on subsequent visits was recorded. Standard spirometry was performed in all patients starting at age 5. The first valid flow-volume loop after age six was selected for analysis. Significant correlations were observed for the R(rs) and the FEF(50) by IPFT and the FEV(1) and the FEF(25-75) by standard spirometry (r > 0.4 and P < 0.03 for all correlations). These correlations were the strongest for those IPFT measurements obtained within 1 month of diagnosis and when R(rs) was expressed as sG(rs). The correlations observed were independent of the effects of age at diagnosis, gender and presence of Pseudomonas in oropharyngeal cultures at the time of diagnosis. Mean R(rs) declined from 0.050 to 0.027 cm H(2)O/ml/sec with treatment (P < 0.0001). There were no other significant associations found between other IPFT values measured and FEV(1) by spirometry. Measures of airflow obstruction on IPFT, specifically R(rs), sG(rs), and FEF(50), were strongly correlated with future lung function. IPFT measurement of R(rs) in addition to forced expiratory flows may help select patients at the greatest risk of early lung function decline. This study supports the use of R(rs) as a surrogate variable to help assess the impact of early therapies in CF.

PULMONARY DYSFUNCTIONS AS MEASURED BY IMPULSE OSCILLOMETRY (IOS) AMONG PATIENTS WITH MORQUIO'S SYNDROME (MUCOPOLYSACCHARIDOSIS TYPE IVA)

PURPOSE: Morquio's Syndrome (MS) is an inherited metabolic disorder caused by a deficiency of a specific lysosomal enzyme. Patients develop respiratory failure secondary to reduced chest wall compliance, reversible and irreversible airway obstruction, chronic obstructive lung disease and obstructive sleep apnea. Formal respiratory function tests are difficult to perform and to interpret owing to the small size of these patients and to poor patient cooperation. The advent of infant pulmonary function testing (IOS) may identify MS children with significant pulmonary limitations. The aim of this study is to evaluate this hypothesis.

Early lung disease in young children with primary ciliary dyskinesia

Primary ciliary dyskinesia (PCD) is an autosomal recessive disease in which ciliary dysfunction leads to chronic lung, sinus, and middle ear disease. PCD is often not diagnosed until late childhood due to its presumed rarity and the technical expertise necessary for diagnosis; as such, little is known about lung disease in young children with PCD. We report on 3 young children with PCD who had evidence of lung disease on infant pulmonary function testing, bronchoscopy, and/or computed tomography (CT) of the chest before 3 years of age.

High-Resolution Computed Tomography of the Lung in Children with Cystic Fibrosis: Technical Factors

A standard technique that controls for respiratory motion and lung volumes during imaging is necessary if high-resolution computed tomography is to be used as an outcome measure in children with cystic fibrosis. End-inspiratory and expiratory imaging allows for the detection and differentiation of early lung disease. In children ages 0-5 years, a noninvasive controlled ventilation technique is ideal, and can be used in combination with raised-volume infant pulmonary function tests. In older children, a spirometric-assisted or spirometric-triggered technique should be used. With optimal technique, radiation dose settings (kVp and mA) can be lowered to achieve a diagnostic screening high-resolution computed tomography of the lungs at a dose equivalent to that of the chest radiograph.

Pulmonary Manifestations in ΔF508/R117H: In Reply

We appreciate Dr Ren's comments regarding our report of 4 children with the genotype ΔF508/R117H-7T.1 He reports the case of another child identified by a positive immunoreactive trypsinogen/DNA cystic fibrosis (CF) newborn screen with a ΔF508/R117H-7T genotype who grew Pseudomonas aeruginosa from an oropharyngeal culture and demonstrated airway obstruction on infant pulmonary-function testing. We believe these 5 cases, along with those reported by Lording …

Interrupter resistance: What's feasible?

Interrupter resistance (Rint) is one of the easiest ways to assess respiratory resistance during tidal breathing with minimal subject cooperation. This article enclosed current knowledge on technical and practical aspects such as how to measure Rint, and how to calculate Rint. Issues on repeatability of the technique and bronchial responsiveness are discussed. Recommendations on Rint technique are provided on behalf of the Interrupter Technique Subcommittee of the ATS/ERS Working Group on Infant and Young Children Pulmonary Function Testing.

Assessment of bronchial responsiveness in preschool children

Preschool children have a short concentration span and relatively poor cooperation with pulmonary function tests (PFTs). This combination complicates the inhalation protocol and the assessment of bronchodilation/bronchoconstriction in this age group. Bronchial responsiveness can be studied after bronchodilator administration or during bronchial challenge using miscellaneous PFTs. This article enclosed information on when to consider significant a PFT change, and published proposed cutoffs for bronchodilation/bronchoconstriction test. Issues on interpretation of bronchial test are also discussed. Recommendations are provided on behalf of the Interrupter Technique Subcommittee of the ATS/ERS Working Group on Infant and Young Children Pulmonary Function Testing.

Operation and nursing of infant pulmonary function test

目的 检测婴幼儿患呼吸系统疾患时肺功能状况,研究探讨2600型小儿肺功能仪操作方法,以协助临床诊断并指导治疗.方法采用SensorMedics2600型小儿肺功能仪,对611例呼吸系统疾患婴幼儿进行睡眠时潮气呼吸流速容量(TBFV)环、被动呼气流速容量(PFV)曲线检查,部分患儿进行功能残气量(FRC)测定.结果611例患儿中检出肺功能异常者558例(91.32%).其中表现小气道阻力升高505例(82.65%),大气道阻力升高401例(65.63%);同时有大、小气道阻力升高348例(56.96%);呼吸系统静态顺应性降低149例(24.39%),增高6例(0.98%).279例功能残气量测试,增高46例(16.49%),减少104例(37.28%).162例支气管舒张试验阳性68例(41.98%);阴性94例(58.02%).各项指标均正常53例(9.33%).结论本检测方法客观地反映了患儿潮气通气量指标、气道阻力、颇应性、功能残气量情况及气道可逆性,对指导临床诊断治疗及疗效判断有重要的应用意义,正确的操作方法保证了测试结果的准确性和可靠性。

Preoperative polysomnograms and infant pulmonary function tests do not predict prolonged postoperative mechanical ventilation in children following scoliosis repair.

Our objective was the identification of children with scoliosis at higher risk of prolonged postoperative mechanical ventilation (MV) permits improved pre- and perioperative respiratory care to reduce postoperative complications. Pulmonary function testing (PFT) predicts prolonged postoperative MV in children who can reliably perform PFT, but some children cannot perform PFT. The objective of this study was to determine if polysomnography (PSG) or infant pulmonary function testing (IPFT) could predict prolonged postoperative MV (defined as MV >3 days) in children undergoing scoliosis surgery who could not reliably perform PFT. We studied 110 patients (age range, 10.8 +/- 4.9 [SD] years) who had preoperative PSG, and 18 patients (age range, 4.0 +/- 2.9 [SD] years) who had preoperative IPFT prior to undergoing any type of scoliosis repair by the Children's Hospital of Los Angeles Division of Orthopedic Surgery from January 1990- July 2001. The following information was reviewed and correlated: preoperative PSG parameters (baseline and nadir S(aO(2) ), baseline and peak P(ETCO(2) ), and apnea hypopnea index [AHI]), preoperative IPFT parameters (respiratory system compliance [C(rs)], respiratory system resistance [R(rs)], tidal volume [V(T)], and FRC), and length of postoperative MV. Twenty-seven patients (25%) who had PSG and 5 patients (28%) who had IPFT required postoperative MV >3 days. There was no association between baseline and nadir S(aO(2) ) <or= 92%, baseline and peak P(ETCO(2) ), or AHI, and length of postoperative MV. There was no association between IPFT (C(rs), R(rs), V(T), and FRC) and length of postoperative MV. We conclude that neither PSG nor IPFT can predict the need for prolonged postoperative MV following scoliosis surgery in children who could not reliably perform PFT.

The Role of Pulmonary Function Testing in Infants

Tests of pulmonary function are used routinely in school-age and older children to augment or confirm clinical findings obtained by a careful history and physical examination. Spirometry allows both detection of airway obstruction even before wheezing can be heard and objective assessment of medical interventions. Measurement of lung volumes separates those processes that cause restriction from those that do not affect lung size or those that cause air trapping. Serial measurements have yielded important insights into the normal growth and aging of the lung as well as showing how various diseases affect lung and airway growth and repair. Although techniques to measure lung function in infants and toddlers have been available for more than 40 years, they have not been used clinically to the same degree that pulmonary function testing has been used in older children and adults. Possible reasons for infant pulmonary function testing not to be performed routinely relate both to the testing conditions and to the information gained. Chief among the former is the need to sedate all but the youngest infants to perform many of these studies. Both parents (1) and physicians (2) express concern over the need to sedate sick infants, even though the sedation typically is tolerated well. Some tests, such as respiratory inductive plethysmography or the forced oscillation technique, do not require sedation of the infant. Other procedural barriers include what must be done to the infant to obtain the necessary information. For example, measurements of dynamic pulmonary compliance and resistance require placement of an esophageal balloon or catheter and, therefore, are considered invasive. Forced expiratory flows by the rapid thoracic compression (“squeeze”) technique may appear uncomfortable for the infant, although infants do not demonstrate any physiologic signs of distress or discomfort during the testing. Some parents have expressed negative feelings after …

Rational approach to the wheezy infant.

The infant or child presenting to the physician's office with persistent or recurrent wheezing during the first two year's of life poses a diagnostic dilemma. A careful medical history should document risk factors for persistent wheezing, including maternal smoking, feeding practices, environmental history, and family history of asthma or cystic fibrosis (CF). A suggested diagnostic approach to the causes of infantile wheezing is outlined. A chest radiograph is non-specific, but may suggest a congenital airway anomaly. Infant pulmonary function testing (IPFT) can help differentiate between central airflow (intrathoracic, extrathoracic, or fixed) and peripheral airflow obstruction. The infant with either intrathoracic, extrathoracic, or fixed airflow obstruction on the PFT may benefit from flexible fiberoptic bronchoscopy. The infant with either an intrathoracic or fixed airway obstruction should undergo an upper gastrointestinal (UGI) series to evaluate the anatomy for extrinsic tracheal compression. The response to treatment with anti-inflammatory therapy may suggest an inflammatory disease such as asthma or CF. The infant with peripheral airflow obstruction and a good response to bronchodilators (> or =25%) using the forced exhalation technique is given the diagnosis of infantile asthma. The infant with peripheral airflow obstruction and no response to bronchodilators should be evaluated further for possible gastroesophageal reflux disease (GERD), and for other causes, which are associated with wheezing symptoms.

Infant pulmonary testing -- techniques, physiological perspectives and clinical applications.

KEYWORDS infant pulmonary function; pulmonary function; infant; thoracic compression technique; infant physiology A number of technologies have been developed to assess airway physiology in health and disease in infancy. The most commonly used in research related publications include assessment of resistance and compliance of the respiratory system, analyses of tidal volume parameters, various methods of measurements of flow, assessment of lung volume by gas washout or plethysmography, and measurements of gas mixing to assess ventilation inhomogeneity. Physiologic measurements of the infant airway have been most frequently used in longitudinal studies of populations. Such applications have elucidated aspects of airway and lung development, and have given insights into airway size as a contributing factor to wheezing, airway hyperreactivity, as well as the natural history of diseases such as RSV infection, bronchopulmonary dysplasia, and cystic fibrosis. A frequently quoted example of an important application of infant pulmonary function tests (IPFT) is the series of studies conducted in Tucson, Arizona, over the last 2 decades, which were seminal in furthering the understanding of the development of wheezing in infancy and early childhood. 1 The utility of these techniques for assessment of health and disease in individuals, has been more limited. A comprehensive review of the whole range of IPFT is unrealistic within the scope of this session on the wheezy infant, and I will therefore focus on

Effect of forced deflation maneuvers upon measurements of respiratory mechanics in ventilated infants.

To determine the effect of forced deflation maneuvers on respiratory mechanics and to assess the reproducibility of such measurements in intubated infants with lung disease. Prospective study in the pediatric intensive care unit of a university children's hospital. Ten clinically stable infants requiring mechanically assisted ventilation for acute pulmonary disease, mean age 5.9 months (1-18), mean weight 5.8 kg (3.2-13). Two sets of measurements of compliance (Crs) and resistance (Rrs) were obtained at 20-min intervals both before and after +40/-40 cmH(2)O forced deflation maneuvers. Forced deflation measurements were repeated at the end of the study. . Forced deflation caused a significant increase in Crs from 0.53+/-0.09 and 0.58+/-0.11 ml/cmH(2)O/kg to 0.71+/-0.11 and 0.68+/-0.11 ml/cmH(2)O/kg. Rrs measurements did not differ. The low coefficients of variation for repeated measures of the baseline measurements (Crs 4.2+/-0.5%, Rrs 7.1+/-0.8%, for forced vital capacity 8.6+/-2.5%, maximum expiratory flows at 25% vital capacity 16.0%+/-3.3%) confirmed the good reproducibility during stable conditions. Inflation and deflation maneuvers affect subsequent measurements of respiratory system compliance but not measurements of maximum expiratory flow-volume relationships in intubated infants, probably through recruitment of lung volume. Careful interpretation and planning of the sequence of infant pulmonary function testing is necessary to reassure that changes are not related to short-term alterations in volume history.

Infant pulmonary function testing.

Pulmonary function tests in infants have been used for many years, but they have been largely relegated to specialized centers and research purposes. More recently, development of commercial equipment and newer techniques has allowed for more broad use and application of these tests. This review describes different techniques that have been used to study infants and toddlers, and their clinical applications.

Bronchodilator Responsiveness in Normal Infants and Young Children

Purpose of the Study. To evaluate the baseline airway responsiveness to a bronchodilator, albuterol, in normal infants and young children using changes in maximal expiratory flow rates. Study Population. In 2 major children’s hospitals, healthy infants <3 years old were recruited for the study. Exclusion criteria included preterm (<36 weeks’ gestation) birth, congenital malformations, or 2 or more episodes of recurrent wheezing with lower respiratory tract infections. Infants who had chronic respiratory conditions were also excluded. At the time of the study, they had to be free of any respiratory tract symptoms and have not had a cold for the previous 2 weeks. Methods. Questions were asked about prenatal and postnatal smoke exposure. Infant pulmonary function testing was performed at each institution using technologies well-established at each institution (Columbus Children’s Hospital, Columbus, Ohio, and James …

Monitoring early inflammation in CF. Infant pulmonary function testing.

Infant pulmonary function tests (iPFTs) have primarily been used as research tools to further define physiologic pulmonary abnormalities in infants and young children with cystic fibrosis (CF). Methodologies used to measure pulmonary function in infants are described, with particular relevance to CF. A comprehensive review of studies and findings in CF infants using iPFTs is presented. Further goals in improving methodologies and in defining pulmonary disease in CF are presented.

Early pulmonary infection, inflammation, and clinical outcomes in infants with cystic fibrosis.

A thorough understanding of the early natural history of cystic fibrosis (CF) lung disease is critical for the development of effective interventions in the youngest patients. We assessed the evolution of pulmonary infection, inflammation, and clinical course among 40 infants over a 2-year period through annual bronchoalveolar lavage (BAL) for culture and measurements of pro- and anti-inflammatory cytokines, semiannual infant pulmonary function testing, and quarterly clinical evaluations. Both the prevalence of CF pathogens and their density in BAL fluid increased with age. Infants had neutrophilic lower airway inflammation and elevated IL-8 concentrations independent of whether CF pathogens were recovered. Total leukocyte and neutrophil densities and IL-8 concentrations increased with density of CF pathogens in BAL fluid, whether the isolated organism was P. aeruginosa or another pathogen. IL-10 concentrations were similar in CF subjects and non-CF historical controls. Infants generally had suboptimal growth (low weight and height percentiles) and obstructive lung disease (decreased expiratory flows and air trapping). Subjects from whom CF pathogens were isolated at > 10(5) cfu/mL had the worst air trapping and lowest Brasfield chest X-ray scores. Our findings provide a foundation for future studies of early intervention in CF lung disease, including antimicrobial and anti-inflammatory therapy.

Infant's Airway Responsiveness Predicts Asthma at 6 Years of Age

Pulmonology| July 01 2001 Infant’s Airway Responsiveness Predicts Asthma at 6 Years of Age AAP Grand Rounds (2001) 6 (1): 9–10. https://doi.org/10.1542/gr.6-1-9 Views Icon Views Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Cite Icon Cite Search Site Citation Infant’s Airway Responsiveness Predicts Asthma at 6 Years of Age. AAP Grand Rounds July 2001; 6 (1): 9–10. https://doi.org/10.1542/gr.6-1-9 Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search toolbar search search input Search input auto suggest filter your search All PublicationsAll JournalsAAP Grand RoundsPediatricsHospital PediatricsPediatrics In ReviewNeoReviewsAAP NewsAll AAP Sites Search Advanced Search Topics: airway device, airway structure, asthma, histamine, wheezing Source: Palmer LJ, Rye PJ, Gibson NA, et al. Airway responsiveness in early infancy predicts asthma, lung function, and respiratory symptoms by school age. Am J Respir Crit Care Med. 2001;163:37–42. The purpose of this study by investigators at the University of Western Australia and the TVW Telethon Institute for Child Health Research in Perth, Australia, was to determine the relationship between airway hyper-responsiveness in healthy neonates at 1 month of age and the subsequent development of asthma, atopy, lower respiratory tract symptoms, and lung function at 6 years of age. The subjects were randomly recruited from a metropolitan hospital prior to birth between 1987 and 1991. Initial pulmonary function and histamine challenge were performed at approximately 1 month of age, prior to any lower respiratory tract infection or clinical illness. Of the initial 253 children, 120 could be contacted and all agreed to participate in follow-up studies on about their sixth birthday. Comparing the infants available for follow-up with those lost to follow-up identified no significant differences at 1 month of age for any parameters of interest. The infant pulmonary function testing was achieved by the rapid thoracic compression technique measuring maximal flow at functional residual capacity (VmaxFRC). The histamine challenge consisted of increasing doses of nebulized histamine from .125g/L to a maximum of 8.0g/L; the provocation concentration producing a 40% decrease in VmaxFRC was estimated from the log dose-response curve. Skin reactivity was assessed for dust mites, rye grass, cow’s milk and egg white. Pulmonary function testing at 6 years of age was done by conventional spirometry according to American Thoracic Society standards. Repeated pulmonary function testing after increasing nebulized doses of histamine was used to establish the dose-response slope to histamine challenge. Skin testing at this time included the same allergens as before in addition to mixed grass, cat and dog. Careful family histories for respiratory and allergic diseases were obtained at both data intervals. Generalized linear models were constructed to investigate the relationships between the histamine responsiveness at 1 month of age and the respiratory outcome at age 6 years. Of the 120 6-year-olds, 14.2% reported wheezing apart from colds, 35.0% reported wheezing with colds, 25.8% had a usual cough and 32.5% had current or previous physician-diagnosed asthma. The histamine sensitivity at 1 month of age was significantly associated with physician-diagnosed asthma (ever) (P=.003), physician-diagnosed current asthma (P<.001), wheeze with colds (P=.003), wheeze apart from colds (P<.001), and usual cough (P=.05). The subjects with the greatest response to histamine at both 1 month and 6 years of age had the lowest forced expiratory volume at 1 second (FEV1) at 6 years of age. There was no significant association between the histamine sensitivity at 1 month and the atopy-associated factors such as eosinophil count, total serum IgE, and positive skin test reactivity assessed at 6 years of age. The authors conclude from this data that airway... You do not currently have access to this content.

Evaluation of the wheezy infant.

The infant with persistent or recurrent wheezing during the first 2 years of life poses a diagnostic dilemma, which can be a source of anxiety to both physicians and parents. A suggested diagnostic approach to the causes of infantile wheezing is outlined. 1. To review the physiologic considerations of the infant's airways that predispose to wheezing. 2. To discuss the key physical findings, family history, and risk factors associated with wheezing in infants. 3. To develop a rational approach to the differential diagnosis and management of infantile wheezing. The MEDLINE database as well as our clinical experience pertaining to infantile wheezing. This review discusses the diagnostic evaluation and treatment of the wheezing infant. We suggest that infant pulmonary function testing may be used as one diagnostic aid in the workup of the wheezing infant.