The Experts below are selected from a list of 273 Experts worldwide ranked by ideXlab platform
Anne Greenough - One of the best experts on this subject based on the ideXlab platform.
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G11 Lung function, transfusion, Pulmonary Capillary blood volume and sickle cell disease
Archives of Disease in Childhood, 2016Co-Authors: Alan Lunt, Emily Mcghee, Polly Robinson, David C. Rees, Sue Height, Anne GreenoughAbstract:Aims Sickle cell disease is the most common inherited disorder in African and Caribbean populations. Restrictive lung function abnormalities become increasingly common in older patients and indeed are characteristic of sickle chronic lung disease. Young children with SCD, however, frequently have obstructive lung function abnormalities. It is not clear whether the obstructive abnormalities are due to asthma or the elevated Pulmonary Capillary blood volume seen in SCD children because of their chronic anaemia. Such data are essential to determine the most effective preventative strategies. Hence, our aim was to investigate whether blood transfusion in SCD children acutely increased Pulmonary Capillary blood volume (PCBV) and this was associated with increased airways obstruction. Methods Measurements of respiratory system resistance and spirometry were made before and after blood transfusion in 18 children, median age 14.2 (6.6–18.5) years. The respiratory system resistance was measured using impulse oscillometry and a frequency of 5 Hz (Rrs5) and was used to assess small airway function. Lung function results were expressed as the percent predicted for height. Pulmonary Capillary blood volume was measured using the single breath-hold method for gas transfer for carbon monoxide (DLCO) and nitric oxide (DLNO). Pulmonary membrane diffusing capacity (DMCO) and Pulmonary Capillary blood volume (PCBV) were then determined using the Roughton-Forster model. Results Post transfusion, the median Rrs5 increased from 127.4 to 141.3% predicted for height (p Conclusion Significant increases in Pulmonary Capillary blood volume and respiratory system resistance occurred immediately following blood transfusion in children with SCD. Furthermore, the increase in respiratory system resistance significantly correlated with the increase in Pulmonary Capillary blood volume. These results provide evidence of a potential interaction between the increased Pulmonary Capillary blood volume and Pulmonary function abnormalities seen in SCD children.
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lung function transfusion Pulmonary Capillary blood volume and sickle cell disease
Respiratory Physiology & Neurobiology, 2016Co-Authors: Alan Lunt, Emily Mcghee, Polly Robinson, David C. Rees, Sue Height, Anne GreenoughAbstract:Abstract Lung function abnormalities occur in children with sickle cell disease (SCD) and may be associated with elevated Pulmonary blood volume. To investigate that association, we determined whether blood transfusion in SCD children acutely increased Pulmonary Capillary blood volume (PCBV) and increased respiratory system resistance (Rrs5). Measurements of Rrs5 and spirometry were made before and after blood transfusion in 18 children, median age 14.2 (6.6–18.5) years. Diffusing capacity for carbon monoxide and nitric oxide were assessed to calculate the PCBV. Post transfusion, the median Rrs5 had increased from 127.4 to 141.3% predicted ( p p p = 0.0056) and vital capacity ( p = 0.0008) decreased. The increase in Rrs5 correlated with the increase in PCBV ( r = 0.50, p = 0.0493). Increased Pulmonary Capillary blood volume may at least partially explain the lung function abnormalities in SCD children.
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airways obstruction and Pulmonary Capillary blood volume in children with sickle cell disease
Pediatric Pulmonology, 2014Co-Authors: Catherine J Wedderburn, Alan Lunt, David C. Rees, Sue Height, Moira C Dick, Gerrard F Rafferty, Anne GreenoughAbstract:SummaryObjectives and Working Hypothesis Airways obstruction occurs in young children with sickle cell disease (SCD). Our aim was to test the hypothesis that increased Pulmonary Capillary blood volume at least in part explained the increased airways obstruction as this would inform which therapy might be most appropriate to treat the airway obstruction. Study design Observational study. Patient-subject selection Twenty-five SCD children and 25 ethnic origin matched controls were recruited. Methodology Respiratory system resistance, using impulse oscillometry at 5 Hz (R5 %pred), Pulmonary Capillary blood volume (Vc), alveolar volume (VA), and spirometry were assessed before and after bronchodilator (ipratropium bromide). Lung volume measurements were also made. Results The SCD children compared to the controls had a higher R5 %pred before (median 133 (range 88–181)% vs. 102 (83–184)%, P = 0.0046) and after (105 (79–150)% vs. 91 (64–147)%, P = 0.0489) bronchodilator and their median Vc/VA (ml/L) was higher before (26 (18–38) vs. 18 (14–28) P < 0.0001) and after (26 (19–41) vs. 18 (13–27) P < 0.0001) bronchodilator. There were similar decreases in R5 %pred post-bronchodilator in the two groups, but no significant changes in Vc/VA in either group. Vc/VA correlated significantly with R5 %pred in the SCD children only. Conclusions Increased Pulmonary Capillary blood volume contributes to the increased airways obstruction in children with SCD, hence, bronchodilators may be of limited benefit in reducing their airways obstruction. Pediatr Pulmonol. 2014; 49:716–722. © 2013 Wiley Periodicals, Inc.
Bruce D Johnson - One of the best experts on this subject based on the ideXlab platform.
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targeting Pulmonary Capillary permeability to reduce lung congestion in heart failure a randomized controlled pilot trial
European Journal of Heart Failure, 2020Co-Authors: Glenn M Stewart, Bruce D Johnson, Dennis L Sprecher, Yogesh N V Reddy, Masaru Obokata, Steven R Goldsmith, Brad Bart, Anna OughtonAbstract:Aims Lung congestion in patients with heart failure (HF) has traditionally been treated using interventions that reduce Pulmonary Capillary hydrostatic pressure. The transient receptor potential vanilloid 4 (TRPV4) channel regulates fluid transit across the Pulmonary Capillary-interface, and represents a novel target to reduce lung water, independent of Pulmonary Capillary hypertension. This pilot study examined the safety and potential efficacy of TRPV4 blockade as a novel treatment for HF. Methods and results In this randomized, double-blind, placebo-controlled crossover pilot trial, 11 subjects with chronic, compensated HF were treated with a novel TRPV4 antagonist (GSK2798745) or placebo. The primary endpoint was lung diffusing capacity for carbon monoxide (DLCO ) after 7 days of treatment with GSK2798745 as compared to placebo. Secondary endpoints included additional diffusion parameters, spirometry and safety assessments. Compared to placebo, treatment with GSK2798745 resulted in a trend to improvement in DLCO (placebo: -0.336 mL/mmHg/min; GSK2798745: +0.458 mL/mmHg/min; treatment difference: +0.793 mL/mmHg/min; 95% confidence interval: -0.925 to 2.512) that was not statistically significant. GSK2798745 was well-tolerated with no serious adverse events. Conclusion In this pilot trial, GSK2798745 was found to be safe and well-tolerated, with a trend toward improved gas transfer. Further investigation is warranted in larger studies to determine whether treatment with TRPV4 antagonists or alternative treatments targeting Capillary permeability might be effective to improve lung congestion, Pulmonary gas transfer and clinical status in patients with acute or chronic HF.
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Pulmonary Capillary recruitment in response to hypoxia in healthy humans a possible role for hypoxic Pulmonary venoconstriction
Respiratory Physiology & Neurobiology, 2011Co-Authors: Bryan J Taylor, Jesper Kjaergaard, Eric M Snyder, Thomas P Olson, Bruce D JohnsonAbstract:We examined mechanisms by which hypoxia may elicit Pulmonary Capillary recruitment in humans. On separate occasions, twenty-five healthy adults underwent exposure to intravenous saline infusion (30 ml/kg ∼15 min) or 17-h normobaric hypoxia (FIO2=12.5%FIO2=12.5%). Cardiac output (Q˙) and Pulmonary Capillary blood volume (Vc) were measured before and after saline infusion and hypoxic-exposure by a rebreathing method. Pulmonary artery systolic pressure (sPpa) and left ventricular (LV) diastolic function were assessed before and after hypoxic-exposure via echocardiography. Saline infusion increased Q˙ and Vc (P < 0.05) with no change in Vc/Q˙ (P = 0.97). Hypoxic-exposure increased Vc (P < 0.01) despite no change in Q˙ (P = 0.25), increased sPpa (P < 0.01), and impaired LV relaxation. Multiple regression suggested that ∼37% of the hypoxia-mediated increase in Vc was attributable to alterations in Q˙, sPpa and LV diastolic function. In conclusion, hypoxia-induced Pulmonary Capillary recruitment in humans is only partly accounted for by changes in Q˙, sPpa and LV diastolic function. We speculate that hypoxic Pulmonary venoconstriction may play a role in such recruitment.
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Pulmonary Capillary recruitment in response to hypoxia in healthy humans: a possible role for hypoxic Pulmonary venoconstriction?
Respiratory Physiology & Neurobiology, 2011Co-Authors: Bryan J Taylor, Jesper Kjaergaard, Eric M Snyder, Thomas P Olson, Bruce D JohnsonAbstract:We examined mechanisms by which hypoxia may elicit Pulmonary Capillary recruitment in humans. On separate occasions, twenty-five healthy adults underwent exposure to intravenous saline infusion (30 ml/kg ∼15 min) or 17-h normobaric hypoxia (FIO2=12.5%FIO2=12.5%). Cardiac output (Q˙) and Pulmonary Capillary blood volume (Vc) were measured before and after saline infusion and hypoxic-exposure by a rebreathing method. Pulmonary artery systolic pressure (sPpa) and left ventricular (LV) diastolic function were assessed before and after hypoxic-exposure via echocardiography. Saline infusion increased Q˙ and Vc (P
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calculating alveolar Capillary conductance and Pulmonary Capillary blood volume comparing the multiple and single inspired oxygen tension methods
Journal of Applied Physiology, 2010Co-Authors: Maile L Ceridon, Thomas P Olson, Kenneth C Beck, Jordan A Bilezikian, Bruce D JohnsonAbstract:Key elements for determining alveolar-Capillary membrane conductance (Dm) and Pulmonary Capillary blood volume (Vc) from the lung diffusing capacity (Dl) for carbon monoxide (DlCO) or for nitric ox...
Alan Lunt - One of the best experts on this subject based on the ideXlab platform.
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G11 Lung function, transfusion, Pulmonary Capillary blood volume and sickle cell disease
Archives of Disease in Childhood, 2016Co-Authors: Alan Lunt, Emily Mcghee, Polly Robinson, David C. Rees, Sue Height, Anne GreenoughAbstract:Aims Sickle cell disease is the most common inherited disorder in African and Caribbean populations. Restrictive lung function abnormalities become increasingly common in older patients and indeed are characteristic of sickle chronic lung disease. Young children with SCD, however, frequently have obstructive lung function abnormalities. It is not clear whether the obstructive abnormalities are due to asthma or the elevated Pulmonary Capillary blood volume seen in SCD children because of their chronic anaemia. Such data are essential to determine the most effective preventative strategies. Hence, our aim was to investigate whether blood transfusion in SCD children acutely increased Pulmonary Capillary blood volume (PCBV) and this was associated with increased airways obstruction. Methods Measurements of respiratory system resistance and spirometry were made before and after blood transfusion in 18 children, median age 14.2 (6.6–18.5) years. The respiratory system resistance was measured using impulse oscillometry and a frequency of 5 Hz (Rrs5) and was used to assess small airway function. Lung function results were expressed as the percent predicted for height. Pulmonary Capillary blood volume was measured using the single breath-hold method for gas transfer for carbon monoxide (DLCO) and nitric oxide (DLNO). Pulmonary membrane diffusing capacity (DMCO) and Pulmonary Capillary blood volume (PCBV) were then determined using the Roughton-Forster model. Results Post transfusion, the median Rrs5 increased from 127.4 to 141.3% predicted for height (p Conclusion Significant increases in Pulmonary Capillary blood volume and respiratory system resistance occurred immediately following blood transfusion in children with SCD. Furthermore, the increase in respiratory system resistance significantly correlated with the increase in Pulmonary Capillary blood volume. These results provide evidence of a potential interaction between the increased Pulmonary Capillary blood volume and Pulmonary function abnormalities seen in SCD children.
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lung function transfusion Pulmonary Capillary blood volume and sickle cell disease
Respiratory Physiology & Neurobiology, 2016Co-Authors: Alan Lunt, Emily Mcghee, Polly Robinson, David C. Rees, Sue Height, Anne GreenoughAbstract:Abstract Lung function abnormalities occur in children with sickle cell disease (SCD) and may be associated with elevated Pulmonary blood volume. To investigate that association, we determined whether blood transfusion in SCD children acutely increased Pulmonary Capillary blood volume (PCBV) and increased respiratory system resistance (Rrs5). Measurements of Rrs5 and spirometry were made before and after blood transfusion in 18 children, median age 14.2 (6.6–18.5) years. Diffusing capacity for carbon monoxide and nitric oxide were assessed to calculate the PCBV. Post transfusion, the median Rrs5 had increased from 127.4 to 141.3% predicted ( p p p = 0.0056) and vital capacity ( p = 0.0008) decreased. The increase in Rrs5 correlated with the increase in PCBV ( r = 0.50, p = 0.0493). Increased Pulmonary Capillary blood volume may at least partially explain the lung function abnormalities in SCD children.
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airways obstruction and Pulmonary Capillary blood volume in children with sickle cell disease
Pediatric Pulmonology, 2014Co-Authors: Catherine J Wedderburn, Alan Lunt, David C. Rees, Sue Height, Moira C Dick, Gerrard F Rafferty, Anne GreenoughAbstract:SummaryObjectives and Working Hypothesis Airways obstruction occurs in young children with sickle cell disease (SCD). Our aim was to test the hypothesis that increased Pulmonary Capillary blood volume at least in part explained the increased airways obstruction as this would inform which therapy might be most appropriate to treat the airway obstruction. Study design Observational study. Patient-subject selection Twenty-five SCD children and 25 ethnic origin matched controls were recruited. Methodology Respiratory system resistance, using impulse oscillometry at 5 Hz (R5 %pred), Pulmonary Capillary blood volume (Vc), alveolar volume (VA), and spirometry were assessed before and after bronchodilator (ipratropium bromide). Lung volume measurements were also made. Results The SCD children compared to the controls had a higher R5 %pred before (median 133 (range 88–181)% vs. 102 (83–184)%, P = 0.0046) and after (105 (79–150)% vs. 91 (64–147)%, P = 0.0489) bronchodilator and their median Vc/VA (ml/L) was higher before (26 (18–38) vs. 18 (14–28) P < 0.0001) and after (26 (19–41) vs. 18 (13–27) P < 0.0001) bronchodilator. There were similar decreases in R5 %pred post-bronchodilator in the two groups, but no significant changes in Vc/VA in either group. Vc/VA correlated significantly with R5 %pred in the SCD children only. Conclusions Increased Pulmonary Capillary blood volume contributes to the increased airways obstruction in children with SCD, hence, bronchodilators may be of limited benefit in reducing their airways obstruction. Pediatr Pulmonol. 2014; 49:716–722. © 2013 Wiley Periodicals, Inc.
Sue Height - One of the best experts on this subject based on the ideXlab platform.
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G11 Lung function, transfusion, Pulmonary Capillary blood volume and sickle cell disease
Archives of Disease in Childhood, 2016Co-Authors: Alan Lunt, Emily Mcghee, Polly Robinson, David C. Rees, Sue Height, Anne GreenoughAbstract:Aims Sickle cell disease is the most common inherited disorder in African and Caribbean populations. Restrictive lung function abnormalities become increasingly common in older patients and indeed are characteristic of sickle chronic lung disease. Young children with SCD, however, frequently have obstructive lung function abnormalities. It is not clear whether the obstructive abnormalities are due to asthma or the elevated Pulmonary Capillary blood volume seen in SCD children because of their chronic anaemia. Such data are essential to determine the most effective preventative strategies. Hence, our aim was to investigate whether blood transfusion in SCD children acutely increased Pulmonary Capillary blood volume (PCBV) and this was associated with increased airways obstruction. Methods Measurements of respiratory system resistance and spirometry were made before and after blood transfusion in 18 children, median age 14.2 (6.6–18.5) years. The respiratory system resistance was measured using impulse oscillometry and a frequency of 5 Hz (Rrs5) and was used to assess small airway function. Lung function results were expressed as the percent predicted for height. Pulmonary Capillary blood volume was measured using the single breath-hold method for gas transfer for carbon monoxide (DLCO) and nitric oxide (DLNO). Pulmonary membrane diffusing capacity (DMCO) and Pulmonary Capillary blood volume (PCBV) were then determined using the Roughton-Forster model. Results Post transfusion, the median Rrs5 increased from 127.4 to 141.3% predicted for height (p Conclusion Significant increases in Pulmonary Capillary blood volume and respiratory system resistance occurred immediately following blood transfusion in children with SCD. Furthermore, the increase in respiratory system resistance significantly correlated with the increase in Pulmonary Capillary blood volume. These results provide evidence of a potential interaction between the increased Pulmonary Capillary blood volume and Pulmonary function abnormalities seen in SCD children.
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lung function transfusion Pulmonary Capillary blood volume and sickle cell disease
Respiratory Physiology & Neurobiology, 2016Co-Authors: Alan Lunt, Emily Mcghee, Polly Robinson, David C. Rees, Sue Height, Anne GreenoughAbstract:Abstract Lung function abnormalities occur in children with sickle cell disease (SCD) and may be associated with elevated Pulmonary blood volume. To investigate that association, we determined whether blood transfusion in SCD children acutely increased Pulmonary Capillary blood volume (PCBV) and increased respiratory system resistance (Rrs5). Measurements of Rrs5 and spirometry were made before and after blood transfusion in 18 children, median age 14.2 (6.6–18.5) years. Diffusing capacity for carbon monoxide and nitric oxide were assessed to calculate the PCBV. Post transfusion, the median Rrs5 had increased from 127.4 to 141.3% predicted ( p p p = 0.0056) and vital capacity ( p = 0.0008) decreased. The increase in Rrs5 correlated with the increase in PCBV ( r = 0.50, p = 0.0493). Increased Pulmonary Capillary blood volume may at least partially explain the lung function abnormalities in SCD children.
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airways obstruction and Pulmonary Capillary blood volume in children with sickle cell disease
Pediatric Pulmonology, 2014Co-Authors: Catherine J Wedderburn, Alan Lunt, David C. Rees, Sue Height, Moira C Dick, Gerrard F Rafferty, Anne GreenoughAbstract:SummaryObjectives and Working Hypothesis Airways obstruction occurs in young children with sickle cell disease (SCD). Our aim was to test the hypothesis that increased Pulmonary Capillary blood volume at least in part explained the increased airways obstruction as this would inform which therapy might be most appropriate to treat the airway obstruction. Study design Observational study. Patient-subject selection Twenty-five SCD children and 25 ethnic origin matched controls were recruited. Methodology Respiratory system resistance, using impulse oscillometry at 5 Hz (R5 %pred), Pulmonary Capillary blood volume (Vc), alveolar volume (VA), and spirometry were assessed before and after bronchodilator (ipratropium bromide). Lung volume measurements were also made. Results The SCD children compared to the controls had a higher R5 %pred before (median 133 (range 88–181)% vs. 102 (83–184)%, P = 0.0046) and after (105 (79–150)% vs. 91 (64–147)%, P = 0.0489) bronchodilator and their median Vc/VA (ml/L) was higher before (26 (18–38) vs. 18 (14–28) P < 0.0001) and after (26 (19–41) vs. 18 (13–27) P < 0.0001) bronchodilator. There were similar decreases in R5 %pred post-bronchodilator in the two groups, but no significant changes in Vc/VA in either group. Vc/VA correlated significantly with R5 %pred in the SCD children only. Conclusions Increased Pulmonary Capillary blood volume contributes to the increased airways obstruction in children with SCD, hence, bronchodilators may be of limited benefit in reducing their airways obstruction. Pediatr Pulmonol. 2014; 49:716–722. © 2013 Wiley Periodicals, Inc.
David C. Rees - One of the best experts on this subject based on the ideXlab platform.
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G11 Lung function, transfusion, Pulmonary Capillary blood volume and sickle cell disease
Archives of Disease in Childhood, 2016Co-Authors: Alan Lunt, Emily Mcghee, Polly Robinson, David C. Rees, Sue Height, Anne GreenoughAbstract:Aims Sickle cell disease is the most common inherited disorder in African and Caribbean populations. Restrictive lung function abnormalities become increasingly common in older patients and indeed are characteristic of sickle chronic lung disease. Young children with SCD, however, frequently have obstructive lung function abnormalities. It is not clear whether the obstructive abnormalities are due to asthma or the elevated Pulmonary Capillary blood volume seen in SCD children because of their chronic anaemia. Such data are essential to determine the most effective preventative strategies. Hence, our aim was to investigate whether blood transfusion in SCD children acutely increased Pulmonary Capillary blood volume (PCBV) and this was associated with increased airways obstruction. Methods Measurements of respiratory system resistance and spirometry were made before and after blood transfusion in 18 children, median age 14.2 (6.6–18.5) years. The respiratory system resistance was measured using impulse oscillometry and a frequency of 5 Hz (Rrs5) and was used to assess small airway function. Lung function results were expressed as the percent predicted for height. Pulmonary Capillary blood volume was measured using the single breath-hold method for gas transfer for carbon monoxide (DLCO) and nitric oxide (DLNO). Pulmonary membrane diffusing capacity (DMCO) and Pulmonary Capillary blood volume (PCBV) were then determined using the Roughton-Forster model. Results Post transfusion, the median Rrs5 increased from 127.4 to 141.3% predicted for height (p Conclusion Significant increases in Pulmonary Capillary blood volume and respiratory system resistance occurred immediately following blood transfusion in children with SCD. Furthermore, the increase in respiratory system resistance significantly correlated with the increase in Pulmonary Capillary blood volume. These results provide evidence of a potential interaction between the increased Pulmonary Capillary blood volume and Pulmonary function abnormalities seen in SCD children.
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lung function transfusion Pulmonary Capillary blood volume and sickle cell disease
Respiratory Physiology & Neurobiology, 2016Co-Authors: Alan Lunt, Emily Mcghee, Polly Robinson, David C. Rees, Sue Height, Anne GreenoughAbstract:Abstract Lung function abnormalities occur in children with sickle cell disease (SCD) and may be associated with elevated Pulmonary blood volume. To investigate that association, we determined whether blood transfusion in SCD children acutely increased Pulmonary Capillary blood volume (PCBV) and increased respiratory system resistance (Rrs5). Measurements of Rrs5 and spirometry were made before and after blood transfusion in 18 children, median age 14.2 (6.6–18.5) years. Diffusing capacity for carbon monoxide and nitric oxide were assessed to calculate the PCBV. Post transfusion, the median Rrs5 had increased from 127.4 to 141.3% predicted ( p p p = 0.0056) and vital capacity ( p = 0.0008) decreased. The increase in Rrs5 correlated with the increase in PCBV ( r = 0.50, p = 0.0493). Increased Pulmonary Capillary blood volume may at least partially explain the lung function abnormalities in SCD children.
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airways obstruction and Pulmonary Capillary blood volume in children with sickle cell disease
Pediatric Pulmonology, 2014Co-Authors: Catherine J Wedderburn, Alan Lunt, David C. Rees, Sue Height, Moira C Dick, Gerrard F Rafferty, Anne GreenoughAbstract:SummaryObjectives and Working Hypothesis Airways obstruction occurs in young children with sickle cell disease (SCD). Our aim was to test the hypothesis that increased Pulmonary Capillary blood volume at least in part explained the increased airways obstruction as this would inform which therapy might be most appropriate to treat the airway obstruction. Study design Observational study. Patient-subject selection Twenty-five SCD children and 25 ethnic origin matched controls were recruited. Methodology Respiratory system resistance, using impulse oscillometry at 5 Hz (R5 %pred), Pulmonary Capillary blood volume (Vc), alveolar volume (VA), and spirometry were assessed before and after bronchodilator (ipratropium bromide). Lung volume measurements were also made. Results The SCD children compared to the controls had a higher R5 %pred before (median 133 (range 88–181)% vs. 102 (83–184)%, P = 0.0046) and after (105 (79–150)% vs. 91 (64–147)%, P = 0.0489) bronchodilator and their median Vc/VA (ml/L) was higher before (26 (18–38) vs. 18 (14–28) P < 0.0001) and after (26 (19–41) vs. 18 (13–27) P < 0.0001) bronchodilator. There were similar decreases in R5 %pred post-bronchodilator in the two groups, but no significant changes in Vc/VA in either group. Vc/VA correlated significantly with R5 %pred in the SCD children only. Conclusions Increased Pulmonary Capillary blood volume contributes to the increased airways obstruction in children with SCD, hence, bronchodilators may be of limited benefit in reducing their airways obstruction. Pediatr Pulmonol. 2014; 49:716–722. © 2013 Wiley Periodicals, Inc.
