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Jon A. Hardie - One of the best experts on this subject based on the ideXlab platform.

  • Diffusion capacity and CT measures of emphysema and airway wall thickness - relation to Arterial Oxygen Tension in COPD patients.
    European Clinical Respiratory Journal, 2016
    Co-Authors: Eirunn Waatevik Saure, Per Bakke, Tomas M.l. Eagan, Marianne Aanerud, Robert L. Jensen, Thomas Blix Grydeland, Ane Johannessen, Roy Miodini Nilsen, Einar Thorsen, Jon A. Hardie
    Abstract:

    Background : Decreased diffusing capacity of the lung for carbon monoxide (DLCO) is associated with emphysema. DLCO is also related to decreased Arterial Oxygen Tension (PaO 2 ), but there are limited data on associations between PaO 2 and computed tomography (CT) derived measures of emphysema and airway wall thickness. Objective : To examine whether CT measures of emphysema and airway wall thickness are associated with level of Arterial Oxygen Tension beyond that provided by measurements of diffusion capacity and spirometry. Methods : The study sample consisted of 271 smoking or ex-smoking COPD patients from the Bergen COPD Cohort Study examined in 2007–2008. Emphysema was assessed as percent of low-attenuation areas

  • diffusion capacity and ct measures of emphysema and airway wall thickness relation to Arterial Oxygen Tension in copd patients
    European Clinical Respiratory Journal, 2016
    Co-Authors: Eirunn Waatevik Saure, Per Bakke, Tomas M.l. Eagan, Marianne Aanerud, Robert L. Jensen, Thomas Blix Grydeland, Ane Johannessen, Roy Miodini Nilsen, Einar Thorsen, Jon A. Hardie
    Abstract:

    Background : Decreased diffusing capacity of the lung for carbon monoxide (DLCO) is associated with emphysema. DLCO is also related to decreased Arterial Oxygen Tension (PaO 2 ), but there are limited data on associations between PaO 2 and computed tomography (CT) derived measures of emphysema and airway wall thickness. Objective : To examine whether CT measures of emphysema and airway wall thickness are associated with level of Arterial Oxygen Tension beyond that provided by measurements of diffusion capacity and spirometry. Methods : The study sample consisted of 271 smoking or ex-smoking COPD patients from the Bergen COPD Cohort Study examined in 2007–2008. Emphysema was assessed as percent of low-attenuation areas<−950 Hounsfield units (%LAA), and airway wall thickness as standardised measure at an internal perimeter of 10 mm (AWT-Pi10). Multiple linear regression models were fitted with PaO 2 as the outcome variable, and %LAA, AWT-Pi10, DLCO and carbon monoxide transfer coefficient (KCO) as main explanatory variables. The models were adjusted for sex, age, smoking status, and haemoglobin concentration, as well as forced expiratory volume in one second (FEV 1 ). Results : Sixty two per cent of the subjects were men, mean (SD) age was 64 (7) years, mean (SD) FEV 1 in percent predicted was 50 (15)%, and mean PaO 2 (SD) was 9.3 (1.1) kPa. The adjusted regression coefficient (CI) for PaO 2 was –0.32 (−0.04–(−0.019)) per 10% increase in %LAA ( p <0.01). When diffusion capacity and FEV 1 were added to the model, respectively, the association lost its statistical significance. No relationship between airway wall thickness and PaO 2 was found. Conclusion : CT assessment of airway wall thickness is not associated with Arterial Oxygen Tension in COPD patients. Emphysema score measured by chest CT, is related to decreased PaO 2 , but cannot replace measurements of diffusion capacity in the clinical evaluation of hypoxaemia. Keywords: Arterial Oxygen Tension; diffusion capacity; emphysema; airway wall thickness; computed tomography; COPD (Published: 12 May 2016) Citation: European Clinical Respiratory Journal 2016, 3: 29141 - http://dx.doi.org/10.3402/ecrj.v3.29141

  • Diffusion capacity and CT measures of emphysema and airway wall thickness - Relation to Arterial Oxygen Tension in COPD patients
    European Respiratory Journal, 2015
    Co-Authors: Eirunn Waatevik Saure, Per Bakke, Tomas M.l. Eagan, Marianne Aanerud, Robert L. Jensen, Thomas Blix Grydeland, Ane Johannessen, Einar Thorsen, Roy Miodini, Jon A. Hardie
    Abstract:

    Background: There is limited data on the relationship between Arterial Oxygen Tension (PaO2) and computed tomography (CT) derived data on emphysema and airway wall thickness. Objective: To examine the predictive value of measures of emphysema and airway wall thickness from CT scans on PaO2. Methods: The study sample consisted of 271 smoking or ex-smoking COPD patients from the Bergen COPD Cohort Study examined in 2007-2008. Emphysema was assessed as percent of low-attenuation areas < -950 Hounsfield units (%LAA), and airway wall thickness as standardized measures at an internal perimeter of 10mm (Pi10). Multiple linear regression models were fitted with PaO2 as the outcome variable, and %LAA, Pi10, DLCO and/or KCO as predictor variables. Also, adjustments for gender, age, smoking status (current/ex), and haemoglobin (in analyses with DLCO and KCO) were made. Results: 62% of the subjects were men, mean(SD) age was 64(7) years, mean(SD) FEV1 in percent predicted was 50(15)%, and mean PaO2(SD) was 9.3(1.1) kPa. The adjusted regression coefficient (SE) for PaO2 was - 0.32 (0.06) per 10% increase in %LAA (p

  • diffusion capacity and ct measures of emphysema and airway wall thickness relation to Arterial Oxygen Tension in copd patients
    European Respiratory Journal, 2015
    Co-Authors: Eirunn Waatevik Saure, Per Bakke, Tomas M.l. Eagan, Marianne Aanerud, Robert L. Jensen, Thomas Blix Grydeland, Ane Johannessen, Einar Thorsen, Roy Miodini, Jon A. Hardie
    Abstract:

    Background: There is limited data on the relationship between Arterial Oxygen Tension (PaO2) and computed tomography (CT) derived data on emphysema and airway wall thickness. Objective: To examine the predictive value of measures of emphysema and airway wall thickness from CT scans on PaO2. Methods: The study sample consisted of 271 smoking or ex-smoking COPD patients from the Bergen COPD Cohort Study examined in 2007-2008. Emphysema was assessed as percent of low-attenuation areas < -950 Hounsfield units (%LAA), and airway wall thickness as standardized measures at an internal perimeter of 10mm (Pi10). Multiple linear regression models were fitted with PaO2 as the outcome variable, and %LAA, Pi10, DLCO and/or KCO as predictor variables. Also, adjustments for gender, age, smoking status (current/ex), and haemoglobin (in analyses with DLCO and KCO) were made. Results: 62% of the subjects were men, mean(SD) age was 64(7) years, mean(SD) FEV1 in percent predicted was 50(15)%, and mean PaO2(SD) was 9.3(1.1) kPa. The adjusted regression coefficient (SE) for PaO2 was - 0.32 (0.06) per 10% increase in %LAA (p <0.01). When DLCO was added to the equation, the significant relationship between level of emphysema and PaO2 disappeared. No relationship between airway wall thickness and PaO2 was found. Conclusion: Computed tomography assessment of airway wall thickness did not predict Arterial Oxygen Tension. Emphysema, on the other hand, predicts level of Arterial hypoxemia in COPD patients, but not beyond the information offered by DLCO.

  • serial measurements of Arterial Oxygen Tension are associated with mortality in copd
    COPD: Journal of Chronic Obstructive Pulmonary Disease, 2015
    Co-Authors: Marianne Aanerud, Eirunn Waatevik Saure, Per Bakke, Tomas M.l. Eagan, Marta Benet, Xavier Basagana, Josep M Anto, Judith Garciaaymerich, Jon A. Hardie
    Abstract:

    Background: Knowledge on factors associated with mortality can help identify patients with COPD that might benefi t from close monitoring and intervention. Arterial blood gases (ABGs) are related to mortality, but both Arterial Tension of Oxygen (PaO2) and Arterial Tension of carbon dioxide (PaCO2) vary over time. The aim of our study was to investigate the association between repeatedly measured ABGs and mortality in men and women with COPD. Methods: A cohort of 419 Norwegian subjects with COPD, GOLD stage II-IV, aged 40–75, was followed up with up to seven ABGs, measured during stable phase for three years. Cox proportional hazard models were used to quantify the relationship between both single and repeatedly measured ABGs and all-cause mortality after fi ve years, adjusting for age, sex, and the updated BODE index. Results: A total of 64 subjects died during follow-up. Mean initial Arterial Oxygen Tension (standard deviation) was signifi cantly higher in survivors compared to deceased, with PaO2 (in kPa) 9.4 (1.1) versus 8.8 (1.2), p<0.001. Corresponding numbers for PaCO2 were 5.3 (0.5) and 5.5 (0.7), p < 0.001. In analyses adjusting for age, sex, and the updated BODE index hazard ratios – HR(95% confi dence intervals) - for all-cause mortality were 0.73 (0.55, 0.97) and 1.58 (0.90, 2.76) for repeated measures of PaO2 and PaCO2, respectively. Conclusion: Both Arterial Oxygen and carbon dioxide Tension were related to mortality in this study, and Arterial Oxygen Tension added prognostic information to the updated BODE index in COPD.

Eirunn Waatevik Saure - One of the best experts on this subject based on the ideXlab platform.

  • Diffusion capacity and CT measures of emphysema and airway wall thickness - relation to Arterial Oxygen Tension in COPD patients.
    European Clinical Respiratory Journal, 2016
    Co-Authors: Eirunn Waatevik Saure, Per Bakke, Tomas M.l. Eagan, Marianne Aanerud, Robert L. Jensen, Thomas Blix Grydeland, Ane Johannessen, Roy Miodini Nilsen, Einar Thorsen, Jon A. Hardie
    Abstract:

    Background : Decreased diffusing capacity of the lung for carbon monoxide (DLCO) is associated with emphysema. DLCO is also related to decreased Arterial Oxygen Tension (PaO 2 ), but there are limited data on associations between PaO 2 and computed tomography (CT) derived measures of emphysema and airway wall thickness. Objective : To examine whether CT measures of emphysema and airway wall thickness are associated with level of Arterial Oxygen Tension beyond that provided by measurements of diffusion capacity and spirometry. Methods : The study sample consisted of 271 smoking or ex-smoking COPD patients from the Bergen COPD Cohort Study examined in 2007–2008. Emphysema was assessed as percent of low-attenuation areas

  • diffusion capacity and ct measures of emphysema and airway wall thickness relation to Arterial Oxygen Tension in copd patients
    European Clinical Respiratory Journal, 2016
    Co-Authors: Eirunn Waatevik Saure, Per Bakke, Tomas M.l. Eagan, Marianne Aanerud, Robert L. Jensen, Thomas Blix Grydeland, Ane Johannessen, Roy Miodini Nilsen, Einar Thorsen, Jon A. Hardie
    Abstract:

    Background : Decreased diffusing capacity of the lung for carbon monoxide (DLCO) is associated with emphysema. DLCO is also related to decreased Arterial Oxygen Tension (PaO 2 ), but there are limited data on associations between PaO 2 and computed tomography (CT) derived measures of emphysema and airway wall thickness. Objective : To examine whether CT measures of emphysema and airway wall thickness are associated with level of Arterial Oxygen Tension beyond that provided by measurements of diffusion capacity and spirometry. Methods : The study sample consisted of 271 smoking or ex-smoking COPD patients from the Bergen COPD Cohort Study examined in 2007–2008. Emphysema was assessed as percent of low-attenuation areas<−950 Hounsfield units (%LAA), and airway wall thickness as standardised measure at an internal perimeter of 10 mm (AWT-Pi10). Multiple linear regression models were fitted with PaO 2 as the outcome variable, and %LAA, AWT-Pi10, DLCO and carbon monoxide transfer coefficient (KCO) as main explanatory variables. The models were adjusted for sex, age, smoking status, and haemoglobin concentration, as well as forced expiratory volume in one second (FEV 1 ). Results : Sixty two per cent of the subjects were men, mean (SD) age was 64 (7) years, mean (SD) FEV 1 in percent predicted was 50 (15)%, and mean PaO 2 (SD) was 9.3 (1.1) kPa. The adjusted regression coefficient (CI) for PaO 2 was –0.32 (−0.04–(−0.019)) per 10% increase in %LAA ( p <0.01). When diffusion capacity and FEV 1 were added to the model, respectively, the association lost its statistical significance. No relationship between airway wall thickness and PaO 2 was found. Conclusion : CT assessment of airway wall thickness is not associated with Arterial Oxygen Tension in COPD patients. Emphysema score measured by chest CT, is related to decreased PaO 2 , but cannot replace measurements of diffusion capacity in the clinical evaluation of hypoxaemia. Keywords: Arterial Oxygen Tension; diffusion capacity; emphysema; airway wall thickness; computed tomography; COPD (Published: 12 May 2016) Citation: European Clinical Respiratory Journal 2016, 3: 29141 - http://dx.doi.org/10.3402/ecrj.v3.29141

  • Diffusion capacity and CT measures of emphysema and airway wall thickness - Relation to Arterial Oxygen Tension in COPD patients
    European Respiratory Journal, 2015
    Co-Authors: Eirunn Waatevik Saure, Per Bakke, Tomas M.l. Eagan, Marianne Aanerud, Robert L. Jensen, Thomas Blix Grydeland, Ane Johannessen, Einar Thorsen, Roy Miodini, Jon A. Hardie
    Abstract:

    Background: There is limited data on the relationship between Arterial Oxygen Tension (PaO2) and computed tomography (CT) derived data on emphysema and airway wall thickness. Objective: To examine the predictive value of measures of emphysema and airway wall thickness from CT scans on PaO2. Methods: The study sample consisted of 271 smoking or ex-smoking COPD patients from the Bergen COPD Cohort Study examined in 2007-2008. Emphysema was assessed as percent of low-attenuation areas < -950 Hounsfield units (%LAA), and airway wall thickness as standardized measures at an internal perimeter of 10mm (Pi10). Multiple linear regression models were fitted with PaO2 as the outcome variable, and %LAA, Pi10, DLCO and/or KCO as predictor variables. Also, adjustments for gender, age, smoking status (current/ex), and haemoglobin (in analyses with DLCO and KCO) were made. Results: 62% of the subjects were men, mean(SD) age was 64(7) years, mean(SD) FEV1 in percent predicted was 50(15)%, and mean PaO2(SD) was 9.3(1.1) kPa. The adjusted regression coefficient (SE) for PaO2 was - 0.32 (0.06) per 10% increase in %LAA (p

  • diffusion capacity and ct measures of emphysema and airway wall thickness relation to Arterial Oxygen Tension in copd patients
    European Respiratory Journal, 2015
    Co-Authors: Eirunn Waatevik Saure, Per Bakke, Tomas M.l. Eagan, Marianne Aanerud, Robert L. Jensen, Thomas Blix Grydeland, Ane Johannessen, Einar Thorsen, Roy Miodini, Jon A. Hardie
    Abstract:

    Background: There is limited data on the relationship between Arterial Oxygen Tension (PaO2) and computed tomography (CT) derived data on emphysema and airway wall thickness. Objective: To examine the predictive value of measures of emphysema and airway wall thickness from CT scans on PaO2. Methods: The study sample consisted of 271 smoking or ex-smoking COPD patients from the Bergen COPD Cohort Study examined in 2007-2008. Emphysema was assessed as percent of low-attenuation areas < -950 Hounsfield units (%LAA), and airway wall thickness as standardized measures at an internal perimeter of 10mm (Pi10). Multiple linear regression models were fitted with PaO2 as the outcome variable, and %LAA, Pi10, DLCO and/or KCO as predictor variables. Also, adjustments for gender, age, smoking status (current/ex), and haemoglobin (in analyses with DLCO and KCO) were made. Results: 62% of the subjects were men, mean(SD) age was 64(7) years, mean(SD) FEV1 in percent predicted was 50(15)%, and mean PaO2(SD) was 9.3(1.1) kPa. The adjusted regression coefficient (SE) for PaO2 was - 0.32 (0.06) per 10% increase in %LAA (p <0.01). When DLCO was added to the equation, the significant relationship between level of emphysema and PaO2 disappeared. No relationship between airway wall thickness and PaO2 was found. Conclusion: Computed tomography assessment of airway wall thickness did not predict Arterial Oxygen Tension. Emphysema, on the other hand, predicts level of Arterial hypoxemia in COPD patients, but not beyond the information offered by DLCO.

  • serial measurements of Arterial Oxygen Tension are associated with mortality in copd
    COPD: Journal of Chronic Obstructive Pulmonary Disease, 2015
    Co-Authors: Marianne Aanerud, Eirunn Waatevik Saure, Per Bakke, Tomas M.l. Eagan, Marta Benet, Xavier Basagana, Josep M Anto, Judith Garciaaymerich, Jon A. Hardie
    Abstract:

    Background: Knowledge on factors associated with mortality can help identify patients with COPD that might benefi t from close monitoring and intervention. Arterial blood gases (ABGs) are related to mortality, but both Arterial Tension of Oxygen (PaO2) and Arterial Tension of carbon dioxide (PaCO2) vary over time. The aim of our study was to investigate the association between repeatedly measured ABGs and mortality in men and women with COPD. Methods: A cohort of 419 Norwegian subjects with COPD, GOLD stage II-IV, aged 40–75, was followed up with up to seven ABGs, measured during stable phase for three years. Cox proportional hazard models were used to quantify the relationship between both single and repeatedly measured ABGs and all-cause mortality after fi ve years, adjusting for age, sex, and the updated BODE index. Results: A total of 64 subjects died during follow-up. Mean initial Arterial Oxygen Tension (standard deviation) was signifi cantly higher in survivors compared to deceased, with PaO2 (in kPa) 9.4 (1.1) versus 8.8 (1.2), p<0.001. Corresponding numbers for PaCO2 were 5.3 (0.5) and 5.5 (0.7), p < 0.001. In analyses adjusting for age, sex, and the updated BODE index hazard ratios – HR(95% confi dence intervals) - for all-cause mortality were 0.73 (0.55, 0.97) and 1.58 (0.90, 2.76) for repeated measures of PaO2 and PaCO2, respectively. Conclusion: Both Arterial Oxygen and carbon dioxide Tension were related to mortality in this study, and Arterial Oxygen Tension added prognostic information to the updated BODE index in COPD.

Richard A. Ehrenkranz - One of the best experts on this subject based on the ideXlab platform.

  • Changes in Arterial Oxygen Tension when weaning neonates from inhaled nitric oxide
    2020
    Co-Authors: Gregory M. Sokol, Naomi S. Fineberg, Linda L. Wright, Richard A. Ehrenkranz
    Abstract:

    We set out to evaluate changes in Arterial Oxygen Tension (PaO 2 ) when weaning neonates from inhaled nitric oxide (INO). We reviewed the records of 505 prospectively collected INO weaning attempts on 84 neonates with hypoxic respiratory failure. PaO 2 values before and 30 min after weaning attempts were recorded. Relationships between change in PaO 2 and decreases in INO concentrations were investigated using regression analysis and ANOVA. PaO 2 decreased (- 18.7 ± 1.8 torr; P < 0.001) when weaning INO. A stepwise decline in PaO 2 was observed weaning INO from 40 ppm. The greatest decline occurred when INO was discontinued (-42.1 ± 4.1 torr). Forward stepwise multiple regression using variables with significant relationships to the decline in PaO 2 identified the specific dose reduction (P

  • Changes in Arterial Oxygen Tension when weaning neonates from inhaled nitric oxide
    Pediatric Pulmonology, 2001
    Co-Authors: Gregory M. Sokol, Naomi S. Fineberg, Linda L. Wright, Richard A. Ehrenkranz
    Abstract:

    We set out to evaluate changes in Arterial Oxygen Tension (PaO2) when weaning neonates from inhaled nitric oxide (INO). We reviewed the records of 505 prospectively collected INO weaning attempts on 84 neonates with hypoxic respiratory failure. PaO2 values before and 30 min after weaning attempts were recorded. Relationships between change in PaO2 and decreases in INO concentrations were investigated using regression analysis and ANOVA. PaO2 decreased (−18.7 ± 1.8 torr; P 

  • changes in Arterial Oxygen Tension when weaning neonates from inhaled nitric oxide
    Pediatric Pulmonology, 2001
    Co-Authors: Gregory M. Sokol, Naomi S. Fineberg, Linda L. Wright, Richard A. Ehrenkranz
    Abstract:

    We set out to evaluate changes in Arterial Oxygen Tension (PaO2) when weaning neonates from inhaled nitric oxide (INO). We reviewed the records of 505 prospectively collected INO weaning attempts on 84 neonates with hypoxic respiratory failure. PaO2 values before and 30 min after weaning attempts were recorded. Relationships between change in PaO2 and decreases in INO concentrations were investigated using regression analysis and ANOVA. PaO2 decreased (−18.7 ± 1.8 torr; P < 0.001); when weaning INO. A stepwise decline in PaO2 was observed weaning INO from 40 ppm. The greatest decline occurred when INO was discontinued (−42.1 ± 4.1 torr). Forward stepwise multiple regression using variables with significant relationships to the decline in PaO2 identified the specific dose reduction 7(P < 0.001), the prewean PaO2 (P < 0.001), and surfactant therapy (P = 0.018) as the variables best describing the change in PaO2(P = 0.004, r = 0.51). In conclusion, a graded decline in PaO2 occurs when reducing INO. INO should be weaned to less than 1 ppm before discontinuing its use. Prior surfactant treatment appears to enhance the Oxygenation reserve when weaning INO. Pediatr Pulmonol. 2001; 32:14–19. © 2001 Wiley-Liss,Inc.

  • changes in Arterial Oxygen Tension when weaning neonates from inhaled nitric oxide
    1998 Pediatric Academic Societies' Annual Meeting, 2001
    Co-Authors: Gregory M. Sokol, Naomi S. Fineberg, Linda L. Wright, Richard A. Ehrenkranz
    Abstract:

    We set out to evaluate changes in Arterial Oxygen Tension (PaO 2 ) when weaning neonates from inhaled nitric oxide (INO). We reviewed the records of 505 prospectively collected INO weaning attempts on 84 neonates with hypoxic respiratory failure. PaO 2 values before and 30 min after weaning attempts were recorded. Relationships between change in PaO 2 and decreases in INO concentrations were investigated using regression analysis and ANOVA. PaO 2 decreased (- 18.7 ± 1.8 torr; P < 0.001) when weaning INO. A stepwise decline in PaO 2 was observed weaning INO from 40 ppm. The greatest decline occurred when INO was discontinued (-42.1 ± 4.1 torr). Forward stepwise multiple regression using variables with significant relationships to the decline in PaO 2 identified the specific dose reduction (P <0.001), the prewean PaO 2 (P < 0.001), and surfactant therapy (P=0.018) as the variables best describing the change in PaO 2 (P=0.004, r=0.51). In conclusion, a graded decline in PaO 2 occurs when reducing INO. INO should be weaned to less than 1 ppm before discontinuing its use. Prior surfactant treatment appears to enhance the Oxygenation reserve when weaning INO.

  • Arterial Oxygen Tension pao2 declines during inhaled nitric oxide dose reduction ino dr in neonates with hypoxic respiratory failure 1743
    Pediatric Research, 1998
    Co-Authors: Gregory M. Sokol, Richard A. Ehrenkranz
    Abstract:

    Arterial Oxygen Tension (PaO2) Declines During Inhaled Nitric Oxide Dose Reduction (INO DR) in Neonates with Hypoxic Respiratory Failure † 1743

Marianne Aanerud - One of the best experts on this subject based on the ideXlab platform.

  • Diffusion capacity and CT measures of emphysema and airway wall thickness - relation to Arterial Oxygen Tension in COPD patients.
    European Clinical Respiratory Journal, 2016
    Co-Authors: Eirunn Waatevik Saure, Per Bakke, Tomas M.l. Eagan, Marianne Aanerud, Robert L. Jensen, Thomas Blix Grydeland, Ane Johannessen, Roy Miodini Nilsen, Einar Thorsen, Jon A. Hardie
    Abstract:

    Background : Decreased diffusing capacity of the lung for carbon monoxide (DLCO) is associated with emphysema. DLCO is also related to decreased Arterial Oxygen Tension (PaO 2 ), but there are limited data on associations between PaO 2 and computed tomography (CT) derived measures of emphysema and airway wall thickness. Objective : To examine whether CT measures of emphysema and airway wall thickness are associated with level of Arterial Oxygen Tension beyond that provided by measurements of diffusion capacity and spirometry. Methods : The study sample consisted of 271 smoking or ex-smoking COPD patients from the Bergen COPD Cohort Study examined in 2007–2008. Emphysema was assessed as percent of low-attenuation areas

  • diffusion capacity and ct measures of emphysema and airway wall thickness relation to Arterial Oxygen Tension in copd patients
    European Clinical Respiratory Journal, 2016
    Co-Authors: Eirunn Waatevik Saure, Per Bakke, Tomas M.l. Eagan, Marianne Aanerud, Robert L. Jensen, Thomas Blix Grydeland, Ane Johannessen, Roy Miodini Nilsen, Einar Thorsen, Jon A. Hardie
    Abstract:

    Background : Decreased diffusing capacity of the lung for carbon monoxide (DLCO) is associated with emphysema. DLCO is also related to decreased Arterial Oxygen Tension (PaO 2 ), but there are limited data on associations between PaO 2 and computed tomography (CT) derived measures of emphysema and airway wall thickness. Objective : To examine whether CT measures of emphysema and airway wall thickness are associated with level of Arterial Oxygen Tension beyond that provided by measurements of diffusion capacity and spirometry. Methods : The study sample consisted of 271 smoking or ex-smoking COPD patients from the Bergen COPD Cohort Study examined in 2007–2008. Emphysema was assessed as percent of low-attenuation areas<−950 Hounsfield units (%LAA), and airway wall thickness as standardised measure at an internal perimeter of 10 mm (AWT-Pi10). Multiple linear regression models were fitted with PaO 2 as the outcome variable, and %LAA, AWT-Pi10, DLCO and carbon monoxide transfer coefficient (KCO) as main explanatory variables. The models were adjusted for sex, age, smoking status, and haemoglobin concentration, as well as forced expiratory volume in one second (FEV 1 ). Results : Sixty two per cent of the subjects were men, mean (SD) age was 64 (7) years, mean (SD) FEV 1 in percent predicted was 50 (15)%, and mean PaO 2 (SD) was 9.3 (1.1) kPa. The adjusted regression coefficient (CI) for PaO 2 was –0.32 (−0.04–(−0.019)) per 10% increase in %LAA ( p <0.01). When diffusion capacity and FEV 1 were added to the model, respectively, the association lost its statistical significance. No relationship between airway wall thickness and PaO 2 was found. Conclusion : CT assessment of airway wall thickness is not associated with Arterial Oxygen Tension in COPD patients. Emphysema score measured by chest CT, is related to decreased PaO 2 , but cannot replace measurements of diffusion capacity in the clinical evaluation of hypoxaemia. Keywords: Arterial Oxygen Tension; diffusion capacity; emphysema; airway wall thickness; computed tomography; COPD (Published: 12 May 2016) Citation: European Clinical Respiratory Journal 2016, 3: 29141 - http://dx.doi.org/10.3402/ecrj.v3.29141

  • Diffusion capacity and CT measures of emphysema and airway wall thickness - Relation to Arterial Oxygen Tension in COPD patients
    European Respiratory Journal, 2015
    Co-Authors: Eirunn Waatevik Saure, Per Bakke, Tomas M.l. Eagan, Marianne Aanerud, Robert L. Jensen, Thomas Blix Grydeland, Ane Johannessen, Einar Thorsen, Roy Miodini, Jon A. Hardie
    Abstract:

    Background: There is limited data on the relationship between Arterial Oxygen Tension (PaO2) and computed tomography (CT) derived data on emphysema and airway wall thickness. Objective: To examine the predictive value of measures of emphysema and airway wall thickness from CT scans on PaO2. Methods: The study sample consisted of 271 smoking or ex-smoking COPD patients from the Bergen COPD Cohort Study examined in 2007-2008. Emphysema was assessed as percent of low-attenuation areas < -950 Hounsfield units (%LAA), and airway wall thickness as standardized measures at an internal perimeter of 10mm (Pi10). Multiple linear regression models were fitted with PaO2 as the outcome variable, and %LAA, Pi10, DLCO and/or KCO as predictor variables. Also, adjustments for gender, age, smoking status (current/ex), and haemoglobin (in analyses with DLCO and KCO) were made. Results: 62% of the subjects were men, mean(SD) age was 64(7) years, mean(SD) FEV1 in percent predicted was 50(15)%, and mean PaO2(SD) was 9.3(1.1) kPa. The adjusted regression coefficient (SE) for PaO2 was - 0.32 (0.06) per 10% increase in %LAA (p

  • diffusion capacity and ct measures of emphysema and airway wall thickness relation to Arterial Oxygen Tension in copd patients
    European Respiratory Journal, 2015
    Co-Authors: Eirunn Waatevik Saure, Per Bakke, Tomas M.l. Eagan, Marianne Aanerud, Robert L. Jensen, Thomas Blix Grydeland, Ane Johannessen, Einar Thorsen, Roy Miodini, Jon A. Hardie
    Abstract:

    Background: There is limited data on the relationship between Arterial Oxygen Tension (PaO2) and computed tomography (CT) derived data on emphysema and airway wall thickness. Objective: To examine the predictive value of measures of emphysema and airway wall thickness from CT scans on PaO2. Methods: The study sample consisted of 271 smoking or ex-smoking COPD patients from the Bergen COPD Cohort Study examined in 2007-2008. Emphysema was assessed as percent of low-attenuation areas < -950 Hounsfield units (%LAA), and airway wall thickness as standardized measures at an internal perimeter of 10mm (Pi10). Multiple linear regression models were fitted with PaO2 as the outcome variable, and %LAA, Pi10, DLCO and/or KCO as predictor variables. Also, adjustments for gender, age, smoking status (current/ex), and haemoglobin (in analyses with DLCO and KCO) were made. Results: 62% of the subjects were men, mean(SD) age was 64(7) years, mean(SD) FEV1 in percent predicted was 50(15)%, and mean PaO2(SD) was 9.3(1.1) kPa. The adjusted regression coefficient (SE) for PaO2 was - 0.32 (0.06) per 10% increase in %LAA (p <0.01). When DLCO was added to the equation, the significant relationship between level of emphysema and PaO2 disappeared. No relationship between airway wall thickness and PaO2 was found. Conclusion: Computed tomography assessment of airway wall thickness did not predict Arterial Oxygen Tension. Emphysema, on the other hand, predicts level of Arterial hypoxemia in COPD patients, but not beyond the information offered by DLCO.

  • serial measurements of Arterial Oxygen Tension are associated with mortality in copd
    COPD: Journal of Chronic Obstructive Pulmonary Disease, 2015
    Co-Authors: Marianne Aanerud, Eirunn Waatevik Saure, Per Bakke, Tomas M.l. Eagan, Marta Benet, Xavier Basagana, Josep M Anto, Judith Garciaaymerich, Jon A. Hardie
    Abstract:

    Background: Knowledge on factors associated with mortality can help identify patients with COPD that might benefi t from close monitoring and intervention. Arterial blood gases (ABGs) are related to mortality, but both Arterial Tension of Oxygen (PaO2) and Arterial Tension of carbon dioxide (PaCO2) vary over time. The aim of our study was to investigate the association between repeatedly measured ABGs and mortality in men and women with COPD. Methods: A cohort of 419 Norwegian subjects with COPD, GOLD stage II-IV, aged 40–75, was followed up with up to seven ABGs, measured during stable phase for three years. Cox proportional hazard models were used to quantify the relationship between both single and repeatedly measured ABGs and all-cause mortality after fi ve years, adjusting for age, sex, and the updated BODE index. Results: A total of 64 subjects died during follow-up. Mean initial Arterial Oxygen Tension (standard deviation) was signifi cantly higher in survivors compared to deceased, with PaO2 (in kPa) 9.4 (1.1) versus 8.8 (1.2), p<0.001. Corresponding numbers for PaCO2 were 5.3 (0.5) and 5.5 (0.7), p < 0.001. In analyses adjusting for age, sex, and the updated BODE index hazard ratios – HR(95% confi dence intervals) - for all-cause mortality were 0.73 (0.55, 0.97) and 1.58 (0.90, 2.76) for repeated measures of PaO2 and PaCO2, respectively. Conclusion: Both Arterial Oxygen and carbon dioxide Tension were related to mortality in this study, and Arterial Oxygen Tension added prognostic information to the updated BODE index in COPD.

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  • the impact of Arterial Oxygen Tension on venous Oxygen saturation in circulatory failure
    Shock, 2007
    Co-Authors: Kwok M Ho, Richard Harding, Jenny Chamberlain
    Abstract:

    Central and mixed venous Oxygen saturations have been used to guide resuscitation in circulatory failure, but the impact of Arterial Oxygen Tension on venous Oxygen saturation has not been thoroughly evaluated. This observational study investigated the impact of Arterial Oxygen Tension on venous Oxygen saturation in circulatory failure. Twenty critically ill patients with circulatory failure requiring mechanical ventilation and a pulmonary artery catheter in an intensive care unit in a tertiary hospital in Western Australia were recruited. Samples of Arterial blood, central venous blood, and mixed venous blood were simultaneously and slowly drawn from the Arterial, central venous, and pulmonary artery catheter, respectively, at baseline and after the patient was ventilated with 100% inspired Oxygen for 5 min. The blood samples were redrawn after a significant change in cardiac index (≥10%) from the baseline, occurring within 24 h of study enrolment while the patient was ventilated with the same baseline inspired Oxygen concentration, was detected. An increase in inspired Oxygen concentration significantly increased the Arterial Oxygen Tension from 12.5 to 38.4 kPa (93.8-288 mmHg) (mean difference, 25.9 kPa; 95% confidence interval [CI], 7.5-31.9 kPa; P < 0.001) and the venous Oxygen saturation from 69.9% to 76.5% (mean difference, 6.6%; 95% CI, 5.3% - 7.9%; P < 0.001). The effect of Arterial Oxygen Tension on venous Oxygen saturation was more significant than the effect associated with changes in cardiac index (mean difference, 2.8%; 95% CI, -0.2% to 5.8%; P = 0.063). In conclusion, Arterial Oxygen Tension has a significant effect on venous Oxygen saturation, and this effect is more significant and consistent than the effect associated with changes in cardiac index.