Pulmonary Function Testing Laboratories Research Articles

A simple method to assess dynamic hyperinflation outside a pulmonary function test laboratory: The metronome-paced tachypnea test

Lung dynamic hyperinflation (DH) is one of the main determinants of dyspnea in chronic respiratory disease patients. Producing evidence of DH is critical during dyspnea assessment, the objectives being to explain the cause, to target treatments, and to monitor their efficacy. The gold standard method consists in repeated measurement of inspiratory capacity (IC) during cardiopulmonary exercise testing (CPET). Unfortunately, access to CPET is limited and assessment of IC during CPET can be challenging in some patients. An alternative method consists in assessment of IC during the testing known as metronome-paced tachypnea (MPT) challenge. This method is feasible, repeatable, valid (i.e. corelated with dyspnea patients' activities of daily living), and responsive to treatments. However, while its diagnostic performance is acceptable, it is lacking in specificity. Methodological standardization is detailed in the present review, as are the differences between IC changes in CPET and in MPT. As a means of assessing DH, MPT challenge is not only applicable to patients outside a pulmonary function test laboratory, but also easily affordable to any chest physician equipped with a simple spirometry device. A diagnosis threshold of 11% for IC decrease during MPT challenge can be used, albeit while bearing in mind the possibility of a false positive result. Moreover, assessment of IC variations during MPT can help to monitor a patient's overall evolution and response to treatments.

Encuesta sobre la actividad de los laboratorios de función pulmonar. Efectos durante la pandemia por SARS-CoV-2

Following the SARS-CoV-2 pandemic in March 2020, pulmonary function testing (PFT) laboratories underwent a transformation, with a reduction in the number of tests or closure in some cases. The aim of this work was to know the activity of PFT in Spain and the modification of this activity due to the pandemic. A protocolised survey was carried out to members of the PFT laboratories through the Spanish Society of Pneumology and Thoracic Surgery (SEPAR). Thirty-nine hospitals in Spain responded. The pulmonary function tests most frequently performed in the PFT laboratories were forced spirometry with bronchodilator test (100%), body plethysmography (97.4%), CO transfer capacity (97.4%), respiratory muscle strength measured in the mouth (97.4%), 6-minute walking test (94.7%), measurement of exhaled fraction of nitric oxide (92.3%) and incremental exercise test (71.8%).The pandemic led to a significant decrease in the number of tests (35.4%) during 2020 with subsequent recovery in 2021, without reaching pre-pandemic values.The most important changes were increased examination times, working with personal protective equipment and ventilation of the rooms. The performance of the nasopharyngeal swab for SARS-CoV2 testing prior to the tests was not homogeneous in the PFT laboratories. Most hospitals are sufficiently equipped to perform the most common pulmonary function tests. The pandemic resulted in a loss of activity in all hospitals.

Area under the inspiratory flow-volume curve (AIN): Proposed normative values.

Area under expiratory flow-volume curve (AEX) has been shown to be a valuable functional measurement in respiratory physiology. Area under inspiratory flow-volume loop (AIN) also shows promise in characterizing upper and/or lower airflow obstruction. we aimed here to develop normative reference values for AIN, able to ascertain deviations from normal. We analyzed AIN in 4,980 spirometry tests recorded in non-smoking, healthy individuals in the Pulmonary Function Testing Laboratory. The mean (95% confidence interval, CI), standard deviation and median (25th-75th interquartile range) AIN were 16.05 (15.79-16.31), 9.08 and 14.72 (9.12-21.42) L2·sec-1, respectively. The mean (95% CI) and standard deviation of the best-trial measurements for square root of AIN (Sqrt AIN) were 3.84 (3.81-3.87) and 1.14; 4.15 (4.12-4.18) and 1.03 in men, and 2.68 (2.63-2.72) and 0.72 L·sec-1/2 in women. The mean (standard deviation) of pre- and post-bronchodilator Sqrt AIN were 3.71 (1.17) and 3.81 (1.19) L·sec-1/2, respectively. The mean (95% CI), standard deviation and lowest 5th percentile (lower limit of normal, LLN) of Sqrt AIN/Sqrt AEX (%) were 101.3 (100.82-101.88), 18.7, and 71.8%; stratified by gender, it was 102.2 (101.6-102.8), 18.6, and 72.8% in men, and 98 (96.9-99.2), 18.8, and 68.6% in women, respectively. The availability of area under the inspiratory flow-volume curve (AIN) and the derived indices offers a promising opportunity to assess upper airway disease (e.g., involvement of larynx, trachea or major bronchi), especially because some of these measurements appear to be independent of age, race, height, and weight.

Has the pandemic changed the test quality of the pulmonary function test laboratory?

Pulmonary function tests are used in the evaluation of the respiratory system. Maneuvers during spirometry can create aerosols and spread viruses such as SARS-CoV-2. Measures due to the pandemic can negatively affect both the number and the quality of the spirometry tests. There are no comparative studies on this subject. The tests conducted in the spirometry laboratory between November 2019 and November 2021 were evaluated. Four hundred forty patients were included in the study. 50.5% of the patients were male and the mean age was 61.8 ± 16.5 years. The age, gender, height, and weight of the patients were similar. 75.2% (331) of the tests were evaluated as successful. The most common errors in tests were early termination (84.1%), uncooperative patients (29%), and poor effort (22.4%). The types of errors were not different between the two periods. The median number of tests performed for each patient was six. The total number of spirometry tests performed were 262 and 178 for 2019 and 2021 (p= 0.011), but test success remained unchanged over the years (p= 0.513). There was no significant difference between the three operators and the test success (p= 0.909), which was similar for both periods. However, the number of tests performed until the successful maneuver varied significantly (p= 0.009), and fewer maneuvers were required before the pandemic. According to this study, the measures taken during the pandemic did not affect the quality of spirometry, but they did lead to more tests being done up until the successful maneuver was performed.

Surviving White-out: How to Manage Severe Noninfectious Acute Lung Allograft Dysfunction of Unknown Etiology.

Surviving White-out: How to Manage Severe Noninfectious Acute Lung Allograft Dysfunction of Unknown Etiology.

Assessing Airway Resistance Using Plethysmography as Lung Function Testing Among Asymptomatic Rheumatoid Arthritis Patients.

Pulmonary events in rheumatoid arthritis (RA) reflects the involvement of pleurae, lung interstitium, and airways. Overall, pulmonary manifestations are estimated to cause 10–20% of mortalities in RA. Respiratory system involvement as extra-articular presentations of RA is common among some Saudi patients. This study aims to evaluate specific airway conductance (sGaw), airway resistance (Raw), and specific airway resistance (sRaw), using plethysmography. Comparison for deployed methods is made by forced spirometer as an indicator for obstruction among patients with RA. The study sought to use the methods to enhance lung testing among RA patients. An analytical, hospital-based study was carried out at pulmonary function test laboratory, department of respiratory care King Saud Medical City (KSMC). RA patients were selected, with an age group of 18-75years. The tests for Forced spirometer and plethysmography were carried out to assess and analyze how the respiratory mechanism was impacted by the disease. Data collected was analyzed using Statistical Package for Social Sciences (SPSS), version 21. The obstructive and mixed ventilation patterns constituted 15%; the mean values of Raw and sRaw were significantly higher compared to mean values predicted for participants selected during the study, while sGaw was significantly lower compared to mean values predicted for participants selected. Monitoring of airway resistance parameters using plethysmography can be used as indicators of lung function testing among RA patients.

Pre-procedural SARS-CoV-2 PCR testing in the pulmonary function laboratory at a tertiary government hospital in Qatar: A clinical audit.

Background: Prior to pulmonary function testing (PFT), local and international recommendations advise pre-procedural screening. Pulmonary function tests generate aerosol droplets containing millions of viruses, significantly increasing the risk of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission not only to the individuals in and around the PFT office, but also to subsequent patients who undergo the test later in the same room.Methods: This clinical audit was carried out to establish the rate of positive pre-procedural SARS-CoV-2 PCR testing before a PFT. The data were obtained over a 6-week period from our ATS accredited pulmonary function laboratory at the Hamad General Hospital, Qatar (December 01, 2021, to January 10, 2022). The PFT laboratory was closed from January 10, 2022, till the date of this report (January 27, 2022) owing to an increase in COVID cases in the community in Qatar during the fourth wave.Results: All the patients scheduled for PFT were asymptomatic of COVID-19. A total of 331 individuals were scheduled for PFT, and 221 PFTs were performed. There were 109 no-shows for both the PCR and the PFT. Between weeks 1 and 4, all the pre-procedural SARS-CoV-2 PCR tests were negative. The weekly average number of COVID-19 cases in Qatar increased from 157 per 100,000 population in week 1 to 2,918 in week 6.2 There was a similar trend in the pre-procedural SARS-CoV-2 PCR tests that increased and resulted in identifying 9 cases with positive SARS-CoV-2 PCR test over weeks 5 and 6 (Figure 1).Conclusion: As the number of documented positive SARS-CoV-2 PCR tests in the community grew, so did the pre-procedural COVID-19 PCR positivity and the number of no-shows. The large number of no-shows may indicate greater worry or concern about contracting COVID-19 when visiting the hospital amid peak community cases. Our findings further call into question the utility of routinely performing pre-procedural PCR screening in asymptomatic cases when the prevalence of COVID-19 is low in the local population. Perhaps, it is time to consider replacing this with on-the-spot quick antigen testing for more effective use of resources.

Inferring COPD Severity from Tidal Breathing.

To develop an algorithm that can infer the severity level of a COPD patient's airflow limitation from tidal breathing data that is collected by a wearable device. Data was collected from 25 single visit adult volunteers with a confirmed or suspected diagnosis of chronic obstructive pulmonary disease (COPD). The ground truth airflow limitation severity of each subject was determined by applying the Global Initiative for Chronic Obstructive Lung Disease (GOLD) staging criteria to the subject's spirometry results. Spirometry was performed in a pulmonary function test laboratory under the supervision of trained clinical staff. Separately, the subjects' respiratory signal was measured during quiet breathing, and a classification model was built to infer the subjects' level of airflow limitation from the measured respiratory signal. The classification model was evaluated against the ground truth using leave-one-out testing. Severity of airway obstruction was classified as either mild/moderate or severe/very severe with an accuracy of 96.4%. Tidal breathing parameters that are measured with a wearable device can be used to distinguish between different levels of airflow limitation in COPD patients.

How Local SARS-CoV-2 Prevalence Shapes Pulmonary Function Testing Laboratory Protocols and Practices During the COVID-19 Pandemic

In March 2020, the World Health Organization declared COVID-19 a global pandemic.1 Initially, hospitals canceled numerous elective and outpatient medical services, including nonurgent pulmonary function tests (PFTs).2 Gradually, these services were resumed in accordance with national guidelines.3 Organizations including the American Thoracic Society (ATS) and others4,5 have since published recommendations regarding provision of respiratory services in the era of COVID-19. We aimed to evaluate which practices were being most widely adopted by PFT laboratories across the United States and to examine how community COVID-19 prevalence shaped those practices.

Evaluation of the relationship between laboratory parameters and pulmonary function tests in COVID-19 patients.

ObjectiveThe novel coronavirus SARS‐CoV‐2 (COVID‐19) rapidly escalated from its origin in an animal market in Wuhan, China in December 2019 to a global pandemic, and the lungs are the most frequently affected organ. The aim of this study was to investigate the relationship between pulmonary function test parameters and laboratory parameters in COVID‐19.MethodA total of 60 patients who were admitted to the chest diseases department and intensive care unit of our hospital and were diagnosed with COVID‐19 by real‐time PCR analysis of nasopharyngeal swabs were evaluated. Pulmonary function tests and laboratory parameters at admission and on day 7 of treatment were analysed.ResultsOn day 7 of treatment, white blood cell count, CRP, and fibrinogen level were significantly lower than at admission (P = .002, 0.001, and 0.001, respectively), while forced expiratory volume in the first second (FEV1) and forced vital capacity (FVC) values were significantly higher compared with admitting values (P = .001 for both). Correlation analysis showed that the decrease in CRP from admission to day 7 of treatment correlated with the increase in FEV1 (r = 0.616, P = .01) and FVC (r = 0.51, P = .01) during the same period. A decrease in the fibrinogen level was also correlated with an increase in FEV1 (r = 0.345, P = .01) and FVC (r = 0.357, P = .01).ConclusionFibrinogen and CRP levels are easily accessible parameters that may help identify improvement or deterioration in pulmonary function in COVID‐19 patients during follow‐up and discharge while reducing the risk of transmission.

Area under the expiratory flow-volume curve: predicted values by regression and deep learning methods and recommendations for clinical practice

BackgroundIn spirometry, the area under expiratory flow-volume curve (AEX-FV) was found to perform well in diagnosing and stratifying physiologic impairments, potentially lessening the need for complex lung volume testing. Expanding...

Improving Screening for Alpha-1 Antitrypsin Deficiency with Direct Testing in the Pulmonary Function Testing Laboratory.

Alpha-1 antitrypsin deficiency (AATD) is a common but highly underdiagnosed genetic disorder that may lead to chronic obstructive pulmonary disease (COPD), bronchiectasis, and liver disease. Early diagnosis is key to altering the course of disease as well as informing family members of potential risk. This randomized, prospective observational study compares the different testing modalities for AATD testing of at-risk patients initiated in the pulmonary function testing (PFT) laboratory. Providing a recommendation with a prescription for serologic testing, providing a finger-stick testing method (AlphaKit), and providing a buccal swab testing method (AlphaID) were compared to the community standard of referring the patient back to the PFT-ordering provider only. Results show that testing directly in the PFT laboratory has an odds ratio (OR) for completing testing of 35.14 (5.33 - 999.99), p-value of <0.0001, for buccal swab testing and an OR of 17.09 (2.58 - 729.99), p-value of 0.0002, for finger-stick testing compared to the community standard. Providing a prescription was no better than referral back to the PFT-ordering provider with an OR of 2.61(0.33 - 119.36), p-value of 0.6412. Resources needed to have testing performed by the Respiratory Therapy department were minimal with an average time of 1 to 5 minutes per patient tested. Causes of testing refusal were also identified. In conclusion, direct testing for AATD by respiratory therapists at the conclusion of PFT testing shows a significant improvement in rates of testing, especially with testing that utilizes buccal swab sample collection.

Emerging Alternatives to Conventional Clinic Visits in the Era of COVID-19: Adoption of Telehealth at VCU Adult Cystic Fibrosis Center.

Cystic fibrosis (CF) is a genetic disease in which consistent follow-up care is required to avoid a decline in pulmonary and nutritional health. It is believed that if a CF patient ceases treatment for 2 days, this can result in an exacerbation. One week of missed treatments can result in a hospitalization and 1 month of missed treatments can result in an earlier demise. With a global pandemic that has affected more than 9 million people, many CF clinics were required to take steps to avoid transmission of this dangerous virus. This may result in delays in delivery of timely CF care due to closure of clinics and pulmonary function testing (PFT) laboratories and limited staff allowed on site for conducting in-person visits. These measures, along with suggestions from the Cystic Fibrosis Foundation (CFF) to extend the social distancing longer than traditional CDC recommendations for the CF community, create an urgent need to explore novel ways to deliver safer care via new standards in chronic health conditions like CF. Especially, as these preventive strategies may be necessary for long-term maintenance, few objective alternatives exist to guide clinicians and allied health professionals in CF centers how to proceed in this new era. This also presents an opportunity for novel approaches that could improve delivery of CF care with remote monitoring and real-time delivery of care in patients’ home environments. Such emerging approaches could benefit patient care, leading to reduced costs and readmissions and improved access to care, medication adherence, and patient communication. We summarize our own experience and discuss the emerging delivery of CF care which can be generalizable to other pulmonary illnesses.

Restoring Pulmonary and Sleep Services as the COVID-19 Pandemic Lessens. From an Association of Pulmonary, Critical Care, and Sleep Division Directors and American Thoracic Society-coordinated Task Force.

Background: In March 2020, many elective medical services were canceled in response to the coronavirus disease 2019 (COVID-19) pandemic. The daily case rate is now declining in many states and there is a need for guidance about the resumption of elective clinical services for patients with lung disease or sleep conditions.Methods: Volunteers were solicited from the Association of Pulmonary, Critical Care, and Sleep Division Directors and American Thoracic Society. Working groups developed plans by discussion and consensus for resuming elective services in pulmonary and sleep-medicine clinics, pulmonary function testing laboratories, bronchoscopy and procedure suites, polysomnography laboratories, and pulmonary rehabilitation facilities.Results: The community new case rate should be consistently low or have a downward trajectory for at least 14 days before resuming elective clinical services. In addition, institutions should have an operational strategy that consists of patient prioritization, screening, diagnostic testing, physical distancing, infection control, and follow-up surveillance. The goals are to protect patients and staff from exposure to the virus, account for limitations in staff, equipment, and space that are essential for the care of patients with COVID-19, and provide access to care for patients with acute and chronic conditions.Conclusions: Transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a dynamic process and, therefore, it is likely that the prevalence of COVID-19 in the community will wax and wane. This will impact an institution’s mitigation needs. Operating procedures should be frequently reassessed and modified as needed. The suggestions provided are those of the authors and do not represent official positions of the Association of Pulmonary, Critical Care, and Sleep Division Directors or the American Thoracic Society.

Rethinking respiratory function laboratories in the era of coronavirus disease 2019: Considerations for today and the day after

Rethinking respiratory function laboratories in the era of coronavirus disease 2019: Considerations for today and the day after

An Observational and Comparative Study of Diurnal Variation of Spirometry Test Parameters among First and Second Year Normal and Healthy Medical Undergraduate Students

Introduction: This study was designed to assess and compare diurnal variability of FEF25, FEF50, FEF75,FEF25-75, PEF and FEV1 by measuring these parameters during morning and evening hours in normalhealthy subjects.Materials and Method: 190 students were enrolled and divided intogroupsof 8-10 students. Each groupwere directed to appear at different dates in Pulmonary Function Test (PFT) Laboratory at 7:30 AM and againat 5:00 PM for spirometry testing. Spirometry was performed with Spiro Excel 1.1 as per the ATS guidelinesand by trained technician. Finally, data from 169 subjects was found to be complete and appropriate andwas taken for the analysis.Diurnal variability in FEF25, FEF50, FEF75, FEF25-75, PEF and FEV1 weredetermined and compared.Results: Allparameters were more in male than female. All the parameters were significantly high in eveningtests as compared to morning tests except FVC. Diurnal variability among different spirometry parameterswas significantly different (ANOVA, p&lt;0.05) in morning and evening tests. The diurnal variability washighest in large airways as reflected by FEF75 and lowest in smaller airways as reflected by FEF25.The diurnal variability was lowest for FEV1%. It revealed that all parameters exhibit significant diurnalvariability.Conclusion: FEV1, FEF and PEF had shown diurnal variability which was directly related to the airwaycalibre. Greater variability was seen in PEF as compared to FEV1 i.e. proximal airways showed greaterdiurnal variation than distal airways.

Current Bronchodilator Responsiveness Criteria Underestimate Asthma in Older Adults.

Asthma is common in older adults and is confirmed by demonstration of variable expiratory air-flow limitations, typically evaluated by spirometric assessment of bronchodilator responsiveness. However, many patients with clinically suspected asthma and documented air-flow obstruction do not exhibit a post-bronchodilator response that meets or exceeds current established guidelines. We investigated if extending the time from bronchodilator administration to assessment of bronchodilator response increases the yield of spirometry for the diagnosis of asthma in older adults. This was a cross-sectional study. The subjects were non-smokers, ≥ 60y old, and with suspected asthma. Subjects were characterized as (1) those with a positive bronchodilator response on the 30-min post-bronchodilator spirometry, (2) those with a positive bronchodilator response on the 60-min post-bronchodilator spirometry, and (3) those without a positive bronchodilator response but with a positive methacholine challenge test. Factors associated with a late response to bronchodilator were evaluated by using bivariate analysis and by multivariate analysis by using a logistic regression model. This study enrolled 165 subjects. Of these, 81 (49.1%) had a positive bronchodilator response on 30-min post-bronchodilator spirometry; 25 (15.2%) had a positive bronchodilator response on the 1-h post-bronchodilator spirometry; and 59 (35.8%) had no positive bronchodilator response but had a positive methacholine challenge test. On multivariable regression analysis, those with a higher baseline percentage of predicted FEV1, higher scores on a standard asthma control test, and wheezing and/or cough after exercise were more likely to either have a late bronchodilator response or no bronchodilator response. Our study showed that a late positive response to bronchodilator use was more common than previously presumed in older subjects with suspected asthma. Pulmonary function testing laboratories should consider routinely reassessing spirometry at 1 h after bronchodilator use if the earlier assessment did not reveal a significant response.

Use of Recordings of Real Patients to Improve Clinical Integration of a First Year Medical Student Pulmonary Function Testing Laboratory

The Lewis Katz School of Medicine at Temple University annually welcomes 200 students to the MD program. We aim to create an interactive and collaborative experience to promote deep levels of learning for large groups of students. The curriculum is being transitioned from a two‐pass to a single‐pass model (AY 2020–21) with early integration of the basic and clinical sciences.The pulmonary function testing (PFT) laboratory in a first year organ systems course has been redeveloped. Previously, the lab utilized Collins spirometers to allow students to gain experience recording and determining lung volumes and capacities and discussing concepts related to lung function testing and respiratory system mechanics. Advantages of the lab included visualization of the mechanics of the test, and hands‐on data collection and analysis. Disadvantages included frequent technical difficulties with aged spirometers and the lack of direct observation of abnormal lung mechanics, and therefore a disconnect to the pathophysiology learned in a subsequent course.Our goal was to address these issues while encouraging collaboration of basic science and clinical faculty, therefore better connecting physiology concepts with pathophysiologic mechanisms of disease. We redeveloped the lab to use the existing structure of calculations and discussion questions while adding the data and experiences of real patients from the Temple Lung Center who underwent modern pulmonary function testing. A patient with obstructive lung disease, a patient with restrictive lung disease, and a person with normal lung function, were recruited to participate in a video recording.In the session, the students watch a video which includes an explanation of the equipment, review of the procedure, and review of lung volumes/capacities previously learned in lecture format. The footage includes patients performing the lung function testing alongside real time flow‐volume loops and volume‐time graphs. The patients with abnormal lung function are introduced in vignette form with radiographic images. Students discuss each case with faculty and predict what they expect to observe with regards to lung volumes/capacities before watching the patients perform the tests. Students are then asked to use and apply real data collected from the patient in the video with normal lung function and complete discussion questions in their small groups (6/group).The reimagined PFT laboratory allows first year students the opportunity to apply basic science knowledge to real and relevant patient cases. This session allows students to achieve the learning objectives as per the APS Medical Curriculum Objectives Project (www.the‐aps.org/MedPhysObj).This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Evaluation of dynamic lung volumes and capacities in farm laborers exposed to occupational pesticide spraying

Background: The exposure to pesticide spraying during the process of farming in the fields is becoming a health concern among the farm laborers. The frequent and unprotected inhalation of chemical pesticides during spraying process adversely affects the lung functions secondary to development of obstructive lung disorders. Aims and Objectives: The objectives were to evaluate the effect of chemical pesticide spraying on Dynamic lung function tests (DLFT’s) and to compare the various parameters such as forced expiratory volume in 1 s (FEV1), FEV1/forced vital capacity (FVC) ratio, forced expiratory flow 25–75% (FEF25–75%), and maximal voluntary ventilation (MVV) in affected individuals with the normal healthy controls. Materials and Methods: The study samples were divided into two groups, study and control groups. An analytical study was conducted by including 60 individuals with age- and occupation-matched criteria (control group – 30 and study group – 30). Participants were selected randomly from the outpatient department (OPD) premises, with the age group between 20 and 40 years, and both sexes were included. Dynamic lung volumes and capacities were recorded on the computerized RMS HELIOS 702 Spirometer. Results: Dynamic lung volumes and capacities such as FEV1, FEV1/FVC ratio, FEF25–75%, and MVV were evaluated on OPD basis in the pulmonary function test laboratory. Our findings showed that all the DLFT parameter values in case of exposed and affected population were significantly less as compared to the normal healthy controls. This indicates the presence of obstructive lung diseases in such individuals. There was a significant difference between the means of study and control groups, and the affected individuals exposed to chemical pesticides had lower lung function tests as compared to normal population. Conclusion: The findings of the present study provide us with useful evidence about the association of pesticide inhalation exposure with adverse respiratory effects among farm laborers. This occupational hazard requires special attention and preventive measures, as it may increase the risk of pulmonary dysfunctions and mortality associated with these diseases.

Pilot Results from an Integrated Pediatric Pulmonary Clinic on Outcomes in Children with Sickle Cell Disease

Abstract Introduction In children with sickle cell disease (SCD), asthma is a common comorbidity and is associated with increased disease severity when compared to children with SCD without asthma. Other pulmonary conditions, such as obstructive sleep apnea (OSA), are also more common in SCD and adversely affect clinical outcomes. Despite the well-established burden of pulmonary disease in children with SCD, optimal treatment paradigms are not well defined. Methods An integrated pediatric SCD and pulmonary clinic guided by the chronic care model was implemented at the University of Florida in July 2017 with the goal of coordinating subspecialty care and improving the treatment of concomitant pulmonary conditions. Prior to the formation of this clinic (pre-intervention phase), patients were managed separately by pulmonologists and hematologists in a tertiary academic medical center. During the intervention phase, patients received care in an interdisciplinary clinic composed of a pediatric pulmonologist, a pediatric hematologist with expertise in SCD, a respiratory therapist with access to an onsite pulmonary function testing (PFT) laboratory, asthma educator, and a SCD nurse educator/clinic coordinator. The objective of this abstract is to evaluate preliminary clinical outcomes of the integrated SCD-pulmonary clinic during the intervention phase (July 2017-June 2018) compared to 24 months prior to implementation (July 2015-June 2017). We hypothesized an integrated clinic model would improve access to specialized pulmonary care for children with SCD and reduce hospitalizations for vaso-occlusive episodes (VOEs). The primary endpoints are adherence to pulmonary clinic appointments and unplanned acute healthcare utilization for SCD-related complications and/or asthma exacerbations. Secondary endpoints are the number of unplanned packed red blood cell (PRBC) transfusions, percentage of patients able to complete PFTs, and new diagnoses or prescribed treatments during the intervention phase. Results During the intervention phase, 24 unique patients accounted for 40 clinic visits. Reasons for referral to the integrated SCD-pulmonary clinic included asthma (16), a history of severe and/or recurrent acute chest syndrome (12), OSA (3), hypoxia (1), shortness of breath (1), and concern for pulmonary hypertension (1). The mean age of participants was 10 years (range 2-18 years); 79% were male, 22 had hemoglobin (Hb) SS disease, 16 (67%) were being treated with hydroxyurea, and 2 were on chronic transfusion therapy. Mean baseline Hb and reticulocyte count were 9.1 gm/dL (SD 1.2) and 8.5% (SD 4.5), respectively. PFTs were successfully completed in 21 (88%) patients and reported as pre-treatment percent predicted values after adjusting for age, gender, height, and race. Mean forced expiratory volume in 1 second (FEV1) was 90% (SD 12.5), forced vital capacity (FVC) 94% (SD 12), and diffusing capacity of the lungs for carbon monoxide (DLCO) corrected for Hb was 103% (SD 26, measured in 12 patients). Mean duration of follow-up was 8 months (range 1-12 months). During the pre-intervention phase, this cohort accounted for 76 hospitalizations, 42 emergency department (ED) visits, 31 transfusions, and 26 missed pulmonary appointments. During the intervention phase, there were 9 hospitalizations, 7 ED visits, 3 transfusions, and 5 missed appointments. This represents an 86% reduction in unplanned acute healthcare utilization (mean difference (MD) 2.8, 95% CI 1.8-3.7; p&lt;0.0001), a 90% reduction in PRBC transfusions (MD 1.9, 95% CI 0.96-2.78; p&lt;0.001), and an 81% increase in adherence to pulmonary appointments (MD 1.3, 95% CI 0.71-1.92; p&lt;0.001). Twenty-two patients had a confirmed asthma diagnosis, and 8 were diagnosed with OSA. Interventions included personalized asthma action plans (22 patients), inhaled corticosteroids (16), supplemental oxygen during sleep (5), tonsillectomy and adenoidectomy (2), and the initiation of hydroxyurea (1). Conclusions These results demonstrate that interdisciplinary clinics can improve access to subspecialty pulmonary care for children with SCD and support the continued development and implementation of integrated care models. With limited follow-up, the results also suggest integrated SCD and pulmonary care can reduce hospitalizations and ED visits for VOEs, though additional follow-up is required to determine the true treatment effect. Disclosures Black: Bioverativ: Membership on an entity's Board of Directors or advisory committees; NIH: Research Funding; Pfizer: Research Funding; Sancilio Pharmaceuticals: Research Funding; Prolong Pharmaceuticals: Consultancy.