Implementation of standardized cystic fibrosis care algorithm to improve the center data-quality improvement project international collaboration.

BACKGROUND: A collaboration between the University of Michigan (U of M) Cystic Fibrosis Center (CFC) and Marmara University (MU) CFC was initiated to improve the health status of people with cystic fibrosis (pwCF) at MU through implementing Quality Improvement (QI) initiatives. The main aim was to improve lung function in children with FEV1pp <80. The secondary aim was to assess the changes in health related quality of life. METHODS: Included in the project were pwCF who received cystic fibrosis (CF) care at the MU CFC and were 6-18 years of age with an FEV1pp <80. Flow charts were created and a standardized CF care algorithm was implemented. Weekly case review were done to develop individualized treatment plans. Appropriate intervention was applied and patient data were assessed at baseline, 3, 6, 9 and 12 months. The Cystic Fibrosis Revised Questionnaire (CFQ-R) was completed. RESULTS: 55 pwCF were included (mean age:11.8 ± 3.3 years). Mean FEV1pp (SD) at baseline, 6 and 12 month was 63.7 (14.6), 66.9 (16.6), 70.4 (19.2), respectively, with a relative increase of 5.0% in 6 months (p:0.002) and 10.5% in 12 months compared to baseline (p<0.001). Physical functioning, eating problems and respiratory symptoms domains of the CFQ-R questionnaire were improved at the end of the one year for 6-13 (p = 0.024, p = 0.009, p = 0.002) and 13-18 year olds (p = 0.013, p = 0.002, p = 0.038). CONCLUSION: There was significant improvement in pwCF with FEV1<80%pp after implementing this QI project. The processes and assessments used can be adopted by other low-middle income countries to improve similar measures.

Improvements in body mass index of children with cystic fibrosis following implementation of a standardized nutritional algorithm: A quality improvement project.

BACKGROUND: A collaboration between the University of Michigan (UM) Cystic Fibrosis Center (CFC) and Marmara University (MU) CFC was initiated in MU through conducting Quality Improvement projects (QIP). The global aim was to improve nutritional status of children with CF (cwCF), with a specific aim to increase the mean BMI percentile (BMIp) for cwCF by 10 percentile points in 12 months. METHODS: Body mass index (BMI) percentiles of cwCF were categorized as: nutritionally adequate (BMIp ≥ 50%); at risk (BMIp 25%-49%); urgently at risk (BMIp 10%-25%); critically at risk (BMIp < 10%). Appropriate interventions were made according to BMIp category every three months. Forced expiratory volume in one-second percent predicted (FEV1pp), and health-related quality of life (HRQoL) were evaluated. RESULTS: One hundred and eight-two cwCF with a mean age of 9.1 ± 4.3 years were included in the project. Baseline BMIp increased from 25.6 to 37.2 at the 12th month (p < 0.001). In the critically at-risk group BMIp increased from 3.6 to 20.5 (p < 0.001), in the urgently at risk group from 15.9 to 30.8 (p < 0.001), in the at risk group from 37.0 to 44.2 (p < 0.079) and in the nutritionally adequate group the increase was from 66.8 to 69.5 (p < 0.301). FEV1pp also improved significantly, from 81.3 ± 20.6 to 85.9 ± 20.8 (p < 0.001). Physical functioning, eating problems, and respiratory symptoms domains of the HRQoL evaluation improved (p < 0.05). CONCLUSION: This project has led to significant improvements in BMIp, FEV1pp and HRQoL of cwCF; similar projects could easily be implemented by centers in other developing countries.

Assessing the Utility of an Outpatient Exercise Program for Children With Cystic Fibrosis: A Quality Improvement Project.

Children with cystic fibrosis (CF) (cwCF) suffer from inadequate weight gain, failure to thrive, and muscle weakness. The latter may be secondary to disuse atrophy (muscle wasting or reduction in muscle size associated with reduced physical activity and inflammation). Handgrip strength (HGS) is a reliable surrogate for muscle strength and lean body mass. Data from our CF center have shown an association between low HGS and forced expiratory volume in 1 s (FEV1) in cwCF. High-intensity interval training (HIIT) improves physical strength. Therefore, we devised a project to assess implementing a HIIT exercise program in the home setting, in order to improve physical strength in cwCF with HGS ≤ 50th percentile. Patients were instructed to complete 3-5 sessions of HIIT exercises per week. Wilcoxon matched-pairs signed-rank tests were used to compare HGS, FEV1, and body mass index (BMI) percentile at baseline and at a follow-up clinic visit. Follow-up was limited due to the COVID pandemic. Adherence to the HIIT regimen was poor. A total of twenty-nine cwCF participated in the program. However, a total of 13 individuals reported some form of moderate activity at follow-up and therefore constituted our final study population. There was a statistically significant increase in absolute grip strength (AGS) and FEV1 for these individuals. Even though the home HIIT protocol was not followed, the project demonstrated that moderate physical activity in cwCF can lead to significant improvement in HGS and overall physical strength.

Development of an Interdisciplinary Telehealth Care Model in a Pediatric Cystic Fibrosis Center.

Background: People with cystic fibrosis (PCF) have unique physical and emotional needs, which are best met through interdisciplinary care (IDC). In the midst of the pandemic, our center aimed to begin a telehealth care model with an objective to increase successful care visits from baseline of 0-95% by June 26, 2020, including meeting cystic fibrosis (CF) care standards of IDC visits that are coproduced through agenda setting with PCF. Methods: Shifting IDC for pediatric CF patients to telehealth was part of a quality improvement initiative. Our team used asynchronous virtual visits (VVs), with the IDC team members' VVs done on different days than the physician's. Multiple plan-do-study-act cycles were completed to address evolving telehealth needs, including IDC team member flow logistics, communication with PCF, and surveying PCF for the patient perspective. Rates of IDC and agenda setting were measured from March 16, 2020 to June 26, 2020. Results: IDC VVs were at 86% in March 2020 with fluctuations until mid-May when we reached 100% and achieved sustainability. Agenda setting was reached at 100% and maintained. With continued effort, an additional 46.3% of PCF registered for the patient portal, totaling 90.6% with access. Our survey revealed 100% of PCF were able to see IDC team members that they needed to, with 87% "extremely satisfied" and 13% "somewhat satisfied" with their telehealth experience. Conclusions: Successful telehealth in pediatric CF IDC can be achieved through continuous communication, optimal utilization of available technologies, and may help foster unique opportunities to help improve health outcomes.

Quality improvement initiative to improve pulmonary function in pediatric cystic fibrosis patients.

BACKGROUND: Our Cystic Fibrosis (CF) Center initiated a Quality Improvement (QI) project in November 2017 with the goal of improving our patients' forced expiratory volume in 1 second (FEV1) percent predicted (pp) and continued for 1 year. Our specific aim was to increase the relative mean FEV1 pp by 5% in 12 months for CF patients 6 to 21 years old with FEV1 ≤ 80 pp. METHODS: We identified patients with FEV1 ≤ 80 pp, developed cause and effect diagrams (fishbones) to identify contributing factors to FEV1 ≤ 80 pp, and created flowcharts to address barriers. The barriers to adherence that may result in FEV1 ≤ 80 pp were studied using a fishbone. A standardized approach across providers was implemented to individualize care for each patient. Each discipline developed a flowchart to address barriers to improving FEV1. RESULTS: Forty patients were identified (43% male). Their mean age was 16.8 years (range 8.2-21.5 years). Mean FEV1 pp at baseline was 58.6 (range 30-80). The fishbone identified needs for continuing education for patients/families, and providing a treatment plan at each clinic visit. After 6 months of implementation, patients had an improvement in mean FEV1 pp by 6.4% (CI, 0.4%-12.9%). At 12 months, mean FEV1 pp had improved by 14% (CI, 6.5%-21.4%), which exceeded our goal of 5%. CONCLUSION: Through this ongoing project, team members, patients, and families partnered to improve lung function in pediatric CF patients. Flowcharts facilitated a standardized approach across providers to develop individualized treatment plans for patients, which resulted in improved lung function.

3D-printed, externally-implanted, bioresorbable airway splints for severe tracheobronchomalacia.

OBJECTIVES/HYPOTHESIS: To report the clinical safety and efficacy of three-dimensional (3D)-printed, patient-specific, bioresorbable airway splints in a cohort of critically ill children with severe tracheobronchomalacia. STUDY DESIGN: Case series. METHODS: From 2012 to 2018, 15 subjects received 29 splints on their trachea, right and/or left mainstem bronchi. The median age at implantation was 8 months (range, 3-25 months). Nine children were female. Five subjects had a history of extracorporeal membrane oxygenation (ECMO), and 11 required continuous sedation, six of whom required paralytics to maintain adequate ventilation. Thirteen were chronically hospitalized, unable to be discharged, and seven were hospitalized their entire lives. At the time of splint implantation, one subject required ECMO, one required positive airway pressure, and 13 subjects were tracheostomy and ventilator dependent, requiring a median positive end-expiratory pressure (PEEP) of 14 cm H2 O (range, 6-20 cm H2 0). Outcomes collected included level of respiratory support, disposition, and splint-related complications. RESULTS: At the time of discharge from our institution, at a median of 28 days postimplantation (range, 10-56 days), the subject on ECMO was weaned from extracorporeal support, and the subjects who were ventilated via tracheostomy had a median change in PEEP (discharge-baseline) of -2.5 cm H2 O (range, -15 to 2 cm H2 O, P = .022). At median follow-up of 8.5 months (range, 0.3-77 months), all but one of the 12 surviving subjects lives at home. Of the 11 survivors who were tracheostomy dependent preoperatively, one is decannulated, one uses a speaking valve, six use a ventilator exclusively at night, and three remain ventilator dependent. CONCLUSIONS: This case series demonstrates the initial clinical efficacy of the 3D-printed bioresorbable airway splint device in a cohort of critically ill children with severe tracheobronchomalacia. LEVEL OF EVIDENCE: 4 Laryngoscope, 129:1763-1771, 2019.

Emergency airway and ventilator procedures for community based home care staff validation of an educational program.

BACKGROUND: Children discharged home with tracheostomy and chronic mechanical ventilator support are at high risk for complications and adverse events. Private duty nursing and home respiratory care services are a critical support necessary for successful discharge. The literature suggests that there are opportunities for home care staff (HCS) to improve upon the skills necessary to assess and intervene in an emergency thereby increasing the likelihood of improving long-term outcomes. METHODS: HCS (RN, LPN, RRT) participated in a 4-h session comprised of lecture and simulation. Lecture content focused on tracheostomy safety, operation of the Trilogy and LTV home ventilators, and review of their common alarms. Simulation included two scenarios simulating tracheostomy decannulation and mucous plugging events. Participant comfort with tracheostomy and ventilator management skills were measured on a five item self-assessment tool and clinical knowledge was measured using an 11 item multiple choice skills test, both of which were completed before and after the session. We tested to see if there was a change in test scores from pre- to post-intervention. RESULTS: Fifty-four HCS participated in the program and provided complete data sets. The vast majority (68%) were registered nurses, followed by licensed practical nurses (19%) and respiratory therapists (12%). Participant self-reported comfort with emergency skills prior to intervention was 3.2/5 which increased to 4.1/5 after intervention (P > 0.0001). Average test score prior to intervention was 62%, post intervention score increased to 82% which represented significant improvement (P > 0.0001). DISCUSSION: HCS are generally unprepared to intervene in an acute airway or ventilator emergency. This short, manageable program provided education that resulted in a significant improvement in both skill level and confidence.

Infant lung function tests as endpoints in the ISIS multicenter clinical trial in cystic fibrosis.

BACKGROUND: The Infant Study of Inhaled Saline (ISIS) in CF was the first multicenter clinical trial to utilize infant pulmonary function tests (iPFTs) as an endpoint. METHODS: Secondary analysis of ISIS data was conducted in order to assess feasibility of iPFT measures and their associations with respiratory symptoms. Standard deviations were calculated to aid in power calculations for future clinical trials. RESULTS: Seventy-three participants enrolled, 70 returned for the final visit; 62 (89%) and 45 (64%) had acceptable paired functional residual capacity (FRC) and raised volume measurements, respectively. Mean baseline FEV0.5, FEF75 and FRC z-scores were 0.3 (SD: 1.2), -0.2 (SD: 2.0), and 1.8 (SD: 2.0). CONCLUSIONS: iPFTs are not appropriate primary endpoints for multicenter clinical trials due to challenges of obtaining acceptable data and near-normal average raised volume measurements. Raised volume measures have potential to serve as secondary endpoints in future clinical CF trials.

Improving nutritional status in a pediatric cystic fibrosis center.

BACKGROUND: The nutritional status of patients with cystic fibrosis (CF) is strongly associated with pulmonary function, respiratory status and survival. Malnutrition could result from a discrepancy between energy needs and food intake while malabsorption results from pancreatic insufficiency which occurs in 85% of people with CF. METHODS: A quality improvement (QI) project was designed to improve the nutritional status of patients with CF with low Body Mass Index (BMI) between 3 and 19 years of age. An algorithm was developed which included clinic-based assessments of patients' nutritional status and periodic assessment by a dietitian, social worker and/or psychologist during the project. Gastrostomy tube placement and feeding was offered as a last resort to improve caloric intake. RESULTS: 173 patients seen during January-June, 2010, were included in this project. They were classified into four BMI groups and data were collected quarterly through June, 2012. The project target population (BMI percentile ≤ 24) had a median BMI percentile at the start of the project of 11.8. At the end of the project median BMI percentile was 22 (46% improvement). CONCLUSION: Improving nutrition and BMI for patients with CF is achievable. There must be a motivated, multi-disciplinary team that includes patients and families. A patient-specific combination of interventions must be used. These interventions could be quite basic for patients with BMI percentile ≥ 25, yet more elaborate for patients with BMI percentile <25. Clinic-based algorithms such as ours can successfully improve the BMI percentile in patients with CF.

Hypervitaminosis A causing hypercalcemia in cystic fibrosis. Case report and focused review.

Hypercalcemia is a rare complication of hypervitaminosis A. We report a pediatric patient with cystic fibrosis (CF) and pancreatic insufficiency who was found to have hypervitaminosis A causing hypercalcemia, complicated by nephrocalcinosis and renal impairment. The patient is a 4-year-old girl with pancreatic-insufficient CF, gastroesophageal reflux, oral aversion, and failure to thrive requiring gastrostomy tube placement. She was prescribed Source CF vitamins, but rarely received the full dose, due to emesis and intolerance. She had routine annual labs that revealed hypercalcemia with elevated blood urea nitrogen and creatinine, which were not present in her previous annual labs. Upon further questioning, her mother reported that she seemed more fatigued for a few weeks, had abdominal pain, and was urinating more frequently. Upon admission to the hospital, laboratory results revealed elevated HCO3, while serum levels of potassium, phosphorus, and albumin were within normal limits. Vitamin D (25-hydroxy) level was low, and vitamin A level was elevated. Extensive metabolic and hormonal workup for the etiology of the hypercalcemia revealed evidence of chronic renal insufficiency and elevated vitamin A levels. She had a renal ultrasound that revealed bilateral nephrocalciosis. Diagnosis of chronic hypervitaminosis A complicated by hypercalcemia was made and was managed by holding vitamin A supplements, aggressive diuresis, and prednisolone. This case emphasizes the importance of regular vitamin A monitoring in patients with CF. There is a wide variability for the lowest intake required to cause toxicity, and the lower limit to cause toxicity has not been determined.

Predictors of early lung function in patients with congenital diaphragmatic hernia.

PURPOSE: Long-term pulmonary outcomes of congenital diaphragmatic hernia (CDH) have demonstrated airflow obstruction in later childhood. We examined pulmonary function data to assess what factors predict lung function in the first three years of life in children with CDH. METHODS: This was a retrospective study of patients treated for CDH who underwent infant pulmonary function testing (IPFT) between 2006 and 2012. IPFT was performed using the raised volume rapid thoracoabdominal compression technique and plethysmography. RESULTS: Twenty-nine neonates with CDH had IPFTs in the first 3years of life. Their mean predicted survival using the CDH Study Group equation was 63%±4%. Fourteen infants (48%) required extracorporeal membrane oxygenation (ECMO). The mean age at IPFT was 85.1±5weeks. Airflow obstruction was the most common abnormality, seen in 14 subjects. 12 subjects had air trapping, and 9 demonstrated restrictive disease. ECMO (p=0.002), days on the ventilator (p=0.028), and days on oxygen (p=0.023) were associated with restrictive lung disease. CONCLUSION: Despite following a group of patients with severe CDH, lung function revealed mild deficits in the first three years of life. Clinical markers of increased severity (ECMO, ventilator days, and prolonged oxygen use) are correlated with reduced lung function.

Bronchodilator responsiveness in wheezy infants and toddlers is not associated with asthma risk factors.

BACKGROUND: There are limited data assessing bronchodilator responsiveness (BDR) in infants and toddlers with recurrent wheezing, and factors associated with a positive response. OBJECTIVES: In a multicenter study of children ≤ 36 months old, we assessed the prevalence of and factors associated with BDR among infants/toddlers with recurrent episodes of wheezing. METHODS: Forced expiratory flows and volumes using the raised-volume rapid thoracic compression method were measured in 76 infants/toddlers [mean (SD) age 16.8 (7.6) months] with recurrent wheezing before and after administration of albuterol. Prior history of hospitalization or emergency department treatment for wheezing, use of inhaled or systemic corticosteroids, physician treatment of eczema, environmental tobacco smoke exposure, and family history of asthma or allergic rhinitis were ascertained. RESULTS: Using the published upper limit of normal for post bronchodilator change (FEV(0.5) ≥ 13% and/or FEF(25-75) ≥ 24%) in healthy infants, 24% (n = 18) of children in our study exhibited BDR. The BDR response was not associated with any clinical factor other than body size. Dichotomizing subjects into responders (defined by published limits of normal) or by quartile to identify children with the greatest change from baseline (4th quartile vs. other) did not identify any other factor associated with BDR. CONCLUSIONS: Approximately one quarter of infants/toddlers with recurrent wheezing exhibited BDR at their clinical baseline. However, BDR in wheezy infants/toddlers was not associated with established clinical asthma risk factors.

Longitudinal measures of lung function in infants with bronchopulmonary dysplasia.

We previously demonstrated that infants with a history of bronchopulmonary dysplasia (BPD) exhibit airflow obstruction and air trapping. The purpose of this study was to assess longitudinal changes in pulmonary function in infants with a history of BPD over the first 3 years of life, and the relationship to somatic growth. Spirometry was measured using the raised volume rapid thoracoabdominal compression technique, and lung volumes measured by plethysmography. Eighteen infants (mean gestational age ± SD 27.3 ± 2.2 weeks, birthweight 971 ± 259 g) underwent two lung function studies. Average age at first test was 58.8 weeks. Spirometry demonstrated significant reductions in forced expiratory volume in 0.5 sec (FEV(0.5), 76.0 ± 15.9% predicted, Z-score -2.13 ± 1.69), forced expiratory flow at 75% of expired forced vital capacity (FEF(75), 54.8 ± 31.1%, -3.58 ± 2.73), and FEF(25-75) (67.8 ± 33.3%, -1.79 ± 1.76). Group mean total lung capacity (TLC) was in the low normal range (82.9 ± 13.5% predicted) and residual volume (RV)/TLC was mildly elevated (122.4 ± 38.2% predicted). Repeat testing was performed an average of 32.7 weeks after initial testing. At re-evaluation, group mean lung volumes and flows tracked at or near their previous values; thus, in general, there was a lack of catch-up growth. However, compared to infants with below average or average somatic growth (as represented by g/day), infants with above average growth showed significantly greater improvements in percent predicted FVC, FEV(0.5), TLC, and RV/TLC (all P < 0.05, ANOVA). We conclude that longitudinal measures of pulmonary function in infants and young children with BPD demonstrate significant airflow obstruction and modest restriction, which tends to persist with time. On the other hand, infants with above average somatic growth showed greater lung growth than their peers. Additional studies examining the effects of various nutritional regimens on lung function are warranted.

Predictors of insufficient sweat production during confirmatory testing for cystic fibrosis.

Michigan's Newborn Screening (NBS) Program began statewide screening for cystic fibrosis (CF) in October 2007. Confirmatory sweat testing is performed in infants having initial immunoreactive trypsinogen concentrations ≥ 99.8th percentile or ≥ 96 th percentile and at least one CF mutation identified by DNA analysis. Some infants fail to produce a sufficient quantity of sweat (QNS-quantity not sufficient) to test for CF, meaning disease confirmation is delayed and sweat testing is later repeated. In this study, we evaluate predictors of QNS results. Information from the linked birth certificates and NBS diagnostic confirmation data were used. The study population was resident infants born in Michigan in 2008 who underwent a sweat test. Bivariate analyses revealed that preterm birth, low birth weight, CF care center, and race were significantly associated with QNS sweat testing results. Adjusted analyses indicated that preterm infants were 2.4 times more likely to have QNS results (95% CI 0.9, 6.4). When age at time of test, accounting for gestational age (gestational age at delivery plus postdelivery age of life=corrected age), was used in the multivariable model, infants <39 weeks were 7.4 times more likely to have QNS results (95% CI 2.5, 21.8). Waiting to sweat test until an infant is aged 39 weeks or more (corrected age) would likely reduce the rate of QNS results, thereby reducing the burden of repeat sweat testing on families and healthcare providers. Further research is necessary to understand the impact of potential delays in diagnosis/treatment relative to postponing sweat testing.

Clinical Applications of Pediatric Pulmonary Function Testing: Lung Function in Recurrent Wheezing and Asthma.

Pulmonary function testing remains the gold standard for the diagnosis and management of wheezing disorders in older children and adults. Although wheezing disorders are among the most common clinical problems in pediatrics, most young children and toddlers cannot perform most of the currently clinically available pulmonary function tests. In this article, we review the different types of pulmonary function tests available and discuss the applicability and utility in the different age groups with specific reference to suitability in the diagnosis and management of wheezing disorders.

Isolation of tracheal aspirate mesenchymal stromal cells predicts bronchopulmonary dysplasia.

BACKGROUND: We have isolated mesenchymal stem cells (MSCs) from tracheal aspirates of premature infants with respiratory distress. Under the influence of transforming growth factor ß, MSCs differentiate into α-smooth-muscle actin-expressing myofibroblasts. Myofibroblasts are increased in the lungs of patients with bronchopulmonary dysplasia (BPD), a chronic lung disease of prematurely born infants. OBJECTIVE: We tested whether isolation of MSCs from tracheal aspirates of premature infants with respiratory distress during the first week of life correlates with BPD. METHODS: Eighty-four infants born at a gestational age of <33 weeks and requiring mechanical ventilation were studied. Aspirates were collected during suctioning and centrifuged. Cell pellets were resuspended in culture medium and plated. Adherent cells were grown to confluence. RESULTS: MSCs were isolated from the tracheal aspirates of 56 infants; 28 aspirate samples showed no MSCs. There was no statistical difference in gestational age or birth weight between the MSC and no-MSC groups. In the MSC group, 12 infants died and 25 developed BPD, as defined by a requirement for supplemental oxygen at 36 weeks' postmenstrual age. In the no-MSC group, 6 infants died and 1 developed BPD. Accounting for potential influences of gender, birth weight, gestational age, number of tracheal aspirate samples taken, and the duration of endotracheal intubation (up to 7 days), isolation of MSCs increased the adjusted odds ratio of BPD more than 21-fold (95% confidence interval: 1.82-265.85). CONCLUSIONS: Isolation of tracheal aspirate MSCs predicts the development of BPD, which suggests that MSCs play an important role in the pathogenesis of this disease.

Pulmonary function in bronchopulmonary dysplasia.

The purpose of this study was to examine lung function and bronchodilator responsiveness in infants with a history of prematurity and bronchopulmonary dysplasia (BPD), using the raised volume rapid thoracoabdominal compression technique as well as with whole-body plethysmography. Spirometric measurements were obtained in 28 infants with a history of BPD, defined as preterm birth with O2 requirement at 36 weeks postmenstrual age (gestational age at birth, 26.4 +/- 2.1 weeks, mean +/- SD; birthweight, 898 +/- 353 g; age at study, 68.0 +/- 35.6 weeks). Fractional lung volumes were measured in 27 subjects. Values were expressed as percentage of predicted normal values. Compared to normal infants, those with a history of BPD exhibited decreases in forced expiratory flows including forced expiratory volume in 0.5 sec (76.3 +/- 19.6%), forced expiratory flow at 75% of expired forced vital capacity (FEF75; 59.5 +/- 30.7%), and FEF(25-75) (74.0 +/- 26.8%; P<0.01 for all). Functional residual capacity (107.9 +/- 25.3%), residual volume (RV, 124.5 +/- 42.7%), and RV/total lung capacity (RV/TLC, 128.2 +/- 35.3%) were increased in infants with a history of BPD (P<0.05 for each). There was no difference in TLC between groups. Seventeen infants were studied both pre- and postalbuterol, and 6 (35%) demonstrated significant bronchodilator responsiveness. Infants with recurrent wheezing showed greater expiratory flow limitation, hyperinflation, and airways responsiveness, whereas those without wheezing showed only modest airway dysfunction. We conclude that infants with a history of BPD have pulmonary function abnormalities characterized by mild to moderate airflow obstruction and air trapping.