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Eucapnic Voluntary Hyperventilation Screen for Bronchospasm Risk During a SCUBA Dive
AB4 Abstracts
SATURDAY
13
Usefulness of Impulse Oscillometry In Children With Eosinophilic Bronchitis Y. Kim1, K. Kim1, J. Baek1, H. Park1, H. Lee2, M. Sohn1, K. Kim1; 1Department of Pediatrics and Institute of Allergy, Severance Biomedical Science Institute, Brain Korea 21 Project for Medical Science, Yonsei University College of Medicine, Seoul, REPUBLIC OF KOREA, 2Kwandong University College of Medicine, Goyang, REPUBLIC OF KOREA. RATIONALE: Eosinophilic bronchitis (EB) has been shown to resolve, whereas it has been shown to progress to asthma in some patients, despite treatment with inhaled steroids. It is controversial whether EB is a pre-form of asthma.We evaluated pulmonary function by impulse oscillometry (IOS) and airway inflammation by measuring fractional exhaled nitric oxide (FeNO) of children with EB in comparison of those with asthma and healthy children as a control. METHODS: A total of 232 children with asthma, 109 with EB, and 115 control subjects were enrolled. We compared pulmonary function test parameters and FeNO levels among three subject groups, and designated a cutoff value of FeNO combined with IOS parameters to distinguish EB from the control group. RESULTS: Pulmonary function and bronchodilator response for EB in spirometry were of normal range as well as for the control. In IOS, the percentage change in reactance at 5 Hz (D X5) and the percentage change in reactance area (D AX) of the EB as well as the asthma groups decreased significantly compared to the control (P < .0001). A cutoff value to distinguish EB from control was D X5 is 220% (sensitivity, 77.5%; specificity, 49.6%), and D AX is 230% (sensitivity, 75.0%; specificity, 46.0%) when FeNO is 20 ppb. CONCLUSIONS: Reversible airway obstruction in IOS and elevated FeNO levels can be useful for evaluation of EB in children. This would support that EB shows airway characteristics similar to those of asthma.
14
Eucapnic Voluntary Hyperventilation Screen for Bronchospasm Risk During a SCUBA Dive R. R. Rosenthal; Johns Hopkins School of Medicine, Baltimore, MD. RATIONALE: Eucapnic Voluntary Hyperventilation (EVH) may be used to duplicate the cold dry air exposure of a SCUBA dive. It should be useful to evaluate the likelihood of bronchospasm in potentially susceptible individuals who wish to dive. METHODS: A 15 year old female student who sought enrollment in a SCUBA diving class had an undocumented history of wheezing after a respiratory infection in the past, was on no medications presently and had normal pulmonary functions. Using a previously described simplified method, she was given an EVH challenge with a target ventilation of 25 times her FEV1 (62.5% of her estimated Maximum Voluntary Ventilation) for 6 minutes. RESULTS: The applicant had a 24.8% decrease in her FEV1 from baseline at 15 minutes after the challenge and required inhaled bronchodilator to restore her pulmonary function to baseline values. She was informed that she would be at risk of exercise induced bronchospasm triggered by the cold dry air of SCUBA exposure during actual dive conditions. This in turn would create the risk of arterial gas embolism, rupture of lung membranes, mediastinal emphysema or pneumothorax due to the expansion of trapped air upon ascent from depth and, accordingly, she was advised not to SCUBA dive. CONCLUSIONS: A simplified method for EVH may be conveniently used to evaluate individuals for the risks attendant to exercise induced bronchospasm triggered by the cold dry air typically ventilated during a SCUBA dive.
J ALLERGY CLIN IMMUNOL FEBRUARY 2012
15
BMI Does Not Correlate with PFTs in Asthma Screening L. A. Wiens; BreatheAmerica, Tulsa, OK. RATIONALE: There is a positive association between asthma and obesity, but the mechanism is unclear. Studies have compared this relationship based on clinical symptoms without correlating objective pulmonary function tests (PFTs) with body mass index (BMI). METHODS: Retrospective chart reviews were performed on 36 patients who had been evaluated for respiratory symptoms within the past 3 years. Initial PFT and BMI measurements were obtained prior to any intervention by the health care provider. RESULTS: Average age of subjects was 41.3 years with a range of 10 to 86 years. There were 10 males and 27 females. Knudson predive values were used for PFTs; BMI was calculated using the following formula: [wt(lbs)/ {ht(in)xht(in)}]x703. Average BMI was 24.5 with a range of 15.0-34.9. Average FEV1 was 82.8 % predicted with a range of 30.8 to146.6. Regression analysis using FEV1, FVC, and FEF25-75 as dependent variables showed no correlation with BMI. (FEV1, p50.783;FVC, p50.275; FEF25-75, p50.874) Correlation between FVC and BMI was (-.284), but did not reach statistical significance. CONCLUSIONS: The relationship between obesity and asthma is based primarily on clinical symptoms, and objective measurements of pulmonary obstruction cannot be predicted by BMI. This lack of correlation would suggest multiple factors are involved in the relationship between asthma and obesity depending on the phenotype of each disease under study. Screening for obesity and asthma in the same clinical setting is unlikely to yield more positive results than either test alone.
16
Patterns of Aeroallergen Sensitization and Development of Sputum Eosinophilia and Airway Hyperresponsiveness S. Kim1,2, W. Song1,2, T. Kim2, S. Lee2, H. Kang2, H. Park2, S. Kim2, Y. Chang1,2, S. Cho2, K. Min2; 1Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam, REPUBLIC OF KOREA, 2 Department of Internal Medicine, Seoul National University College of Medicine, Seoul, REPUBLIC OF KOREA. RATIONALE: Specific aeroallergen sensitization may have more influence on the development of airway inflammation and airway hyperresponsiveness (AHR). This study was aimed to investigate the relationship between aeroallergen sensitization pattern and development of sputum eosinophilia and AHR. METHODS: We retrospectively evaluated the data of skin prick test to aeroallergens, methacholine bronchial provocation test and induced sputum analysis from the patients who had performed all of three tests for the evaluation of their allergic and respiratory symptoms. RESULTS: Mean age of 1207 enrolled subjects was 49.9616.4 and 43.2% were male. 51.9% of them had positive skin test response to at least one _ 3%), and 23.3% had allergen, 38.8% had sputum eosinophilia (eosinophil > _ 16mg/ml). Both sputum eosinophilia and AHR were AHR (PC20 < significantly associated with sensitization to at least one perennial allergen(OR51.8, 95%CI: 1.4-2.3; OR52.6, 95%CI: 1.9-3.5, respectively) and individual allergen sensitizations to house dust mite, indoor mold, cat, and dog, after adjusting for age and gender. There was no significant relationship in seasonal allergens such as tree, grass and weed pollen, outdoor mold, and cockroach. CONCLUSION: Increased sputum eosinophilia and AHR are associated with specific allergen sensitization, especially sensitization to indoor perennial allergens.
SATURDAY
13
Usefulness of Impulse Oscillometry In Children With Eosinophilic Bronchitis Y. Kim1, K. Kim1, J. Baek1, H. Park1, H. Lee2, M. Sohn1, K. Kim1; 1Department of Pediatrics and Institute of Allergy, Severance Biomedical Science Institute, Brain Korea 21 Project for Medical Science, Yonsei University College of Medicine, Seoul, REPUBLIC OF KOREA, 2Kwandong University College of Medicine, Goyang, REPUBLIC OF KOREA. RATIONALE: Eosinophilic bronchitis (EB) has been shown to resolve, whereas it has been shown to progress to asthma in some patients, despite treatment with inhaled steroids. It is controversial whether EB is a pre-form of asthma.We evaluated pulmonary function by impulse oscillometry (IOS) and airway inflammation by measuring fractional exhaled nitric oxide (FeNO) of children with EB in comparison of those with asthma and healthy children as a control. METHODS: A total of 232 children with asthma, 109 with EB, and 115 control subjects were enrolled. We compared pulmonary function test parameters and FeNO levels among three subject groups, and designated a cutoff value of FeNO combined with IOS parameters to distinguish EB from the control group. RESULTS: Pulmonary function and bronchodilator response for EB in spirometry were of normal range as well as for the control. In IOS, the percentage change in reactance at 5 Hz (D X5) and the percentage change in reactance area (D AX) of the EB as well as the asthma groups decreased significantly compared to the control (P < .0001). A cutoff value to distinguish EB from control was D X5 is 220% (sensitivity, 77.5%; specificity, 49.6%), and D AX is 230% (sensitivity, 75.0%; specificity, 46.0%) when FeNO is 20 ppb. CONCLUSIONS: Reversible airway obstruction in IOS and elevated FeNO levels can be useful for evaluation of EB in children. This would support that EB shows airway characteristics similar to those of asthma.
14
Eucapnic Voluntary Hyperventilation Screen for Bronchospasm Risk During a SCUBA Dive R. R. Rosenthal; Johns Hopkins School of Medicine, Baltimore, MD. RATIONALE: Eucapnic Voluntary Hyperventilation (EVH) may be used to duplicate the cold dry air exposure of a SCUBA dive. It should be useful to evaluate the likelihood of bronchospasm in potentially susceptible individuals who wish to dive. METHODS: A 15 year old female student who sought enrollment in a SCUBA diving class had an undocumented history of wheezing after a respiratory infection in the past, was on no medications presently and had normal pulmonary functions. Using a previously described simplified method, she was given an EVH challenge with a target ventilation of 25 times her FEV1 (62.5% of her estimated Maximum Voluntary Ventilation) for 6 minutes. RESULTS: The applicant had a 24.8% decrease in her FEV1 from baseline at 15 minutes after the challenge and required inhaled bronchodilator to restore her pulmonary function to baseline values. She was informed that she would be at risk of exercise induced bronchospasm triggered by the cold dry air of SCUBA exposure during actual dive conditions. This in turn would create the risk of arterial gas embolism, rupture of lung membranes, mediastinal emphysema or pneumothorax due to the expansion of trapped air upon ascent from depth and, accordingly, she was advised not to SCUBA dive. CONCLUSIONS: A simplified method for EVH may be conveniently used to evaluate individuals for the risks attendant to exercise induced bronchospasm triggered by the cold dry air typically ventilated during a SCUBA dive.
J ALLERGY CLIN IMMUNOL FEBRUARY 2012
15
BMI Does Not Correlate with PFTs in Asthma Screening L. A. Wiens; BreatheAmerica, Tulsa, OK. RATIONALE: There is a positive association between asthma and obesity, but the mechanism is unclear. Studies have compared this relationship based on clinical symptoms without correlating objective pulmonary function tests (PFTs) with body mass index (BMI). METHODS: Retrospective chart reviews were performed on 36 patients who had been evaluated for respiratory symptoms within the past 3 years. Initial PFT and BMI measurements were obtained prior to any intervention by the health care provider. RESULTS: Average age of subjects was 41.3 years with a range of 10 to 86 years. There were 10 males and 27 females. Knudson predive values were used for PFTs; BMI was calculated using the following formula: [wt(lbs)/ {ht(in)xht(in)}]x703. Average BMI was 24.5 with a range of 15.0-34.9. Average FEV1 was 82.8 % predicted with a range of 30.8 to146.6. Regression analysis using FEV1, FVC, and FEF25-75 as dependent variables showed no correlation with BMI. (FEV1, p50.783;FVC, p50.275; FEF25-75, p50.874) Correlation between FVC and BMI was (-.284), but did not reach statistical significance. CONCLUSIONS: The relationship between obesity and asthma is based primarily on clinical symptoms, and objective measurements of pulmonary obstruction cannot be predicted by BMI. This lack of correlation would suggest multiple factors are involved in the relationship between asthma and obesity depending on the phenotype of each disease under study. Screening for obesity and asthma in the same clinical setting is unlikely to yield more positive results than either test alone.
16
Patterns of Aeroallergen Sensitization and Development of Sputum Eosinophilia and Airway Hyperresponsiveness S. Kim1,2, W. Song1,2, T. Kim2, S. Lee2, H. Kang2, H. Park2, S. Kim2, Y. Chang1,2, S. Cho2, K. Min2; 1Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam, REPUBLIC OF KOREA, 2 Department of Internal Medicine, Seoul National University College of Medicine, Seoul, REPUBLIC OF KOREA. RATIONALE: Specific aeroallergen sensitization may have more influence on the development of airway inflammation and airway hyperresponsiveness (AHR). This study was aimed to investigate the relationship between aeroallergen sensitization pattern and development of sputum eosinophilia and AHR. METHODS: We retrospectively evaluated the data of skin prick test to aeroallergens, methacholine bronchial provocation test and induced sputum analysis from the patients who had performed all of three tests for the evaluation of their allergic and respiratory symptoms. RESULTS: Mean age of 1207 enrolled subjects was 49.9616.4 and 43.2% were male. 51.9% of them had positive skin test response to at least one _ 3%), and 23.3% had allergen, 38.8% had sputum eosinophilia (eosinophil > _ 16mg/ml). Both sputum eosinophilia and AHR were AHR (PC20 < significantly associated with sensitization to at least one perennial allergen(OR51.8, 95%CI: 1.4-2.3; OR52.6, 95%CI: 1.9-3.5, respectively) and individual allergen sensitizations to house dust mite, indoor mold, cat, and dog, after adjusting for age and gender. There was no significant relationship in seasonal allergens such as tree, grass and weed pollen, outdoor mold, and cockroach. CONCLUSION: Increased sputum eosinophilia and AHR are associated with specific allergen sensitization, especially sensitization to indoor perennial allergens.