Long-term gas exchange characteristics as markers of deterioration in patients with cystic fibrosis

Kraemer Richard, Latzin Philipp, Pramana Isabelle, Ballinari Pietro, Gallati Sabina, Frey, Frey Urs

Description

and Aim In patients with cystic fibrosis (CF) the architecture of the developing lungs and the ventilation of lung units are progressively affected, influencing intrapulmonary gas mixing and gas exchange. We examined the long-term course of blood gas measurements in relation to characteristics of lung function and the influence of different CFTR genotype upon this process. Methods Serial annual measurements of PaO 2 and PaCO 2 assessed in relation to lung function, providing functional residual capacity (FRC pleth ), lung clearance index (LCI), trapped gas (V TG ), airway resistance (sR eff ), and forced expiratory indices (FEV 1 , FEF 50 ), were collected in 178 children (88 males; 90 females) with CF, over an age range of 5 to 18 years. Linear mixed model analysis and binary logistic regression analysis were used to define predominant lung function parameters influencing oxygenation and carbon dioxide elimination. Results PaO 2 decreased linearly from age 5 to 18 years, and was mainly associated with FRC pleth , ( p < 0.0001), FEV 1 ( p < 0.001), FEF 50 ( p < 0.002), and LCI ( p < 0.002), indicating that oxygenation was associated with the degree of pulmonary hyperinflation, ventilation inhomogeneities and impeded airway function. PaCO 2 showed a transitory phase of low PaCO 2 values, mainly during the age range of 5 to 12 years. Both PaO 2 and PaCO 2 presented with different progression slopes within specific CFTR genotypes. Conclusion In the long-term evaluation of gas exchange characteristics, an association with different lung function patterns was found and was closely related to specific genotypes. Early examination of blood gases may reveal hypocarbia, presumably reflecting compensatory mechanisms to improve oxygenation.

Informations

• Publié par: biomed
• Publié le: 01 janvier 2009
• Nombre de lectures: 4
• Langue: English

Extrait

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Bio Med Central

Abstract Background and Aim: In patients with cystic fibrosis (CF) the architecture of the developing lungs and the ventilation of lung units are prog ressively affected, influencing intrapulmonary gas mixing and gas exchange. We examined the lo ng-term course of blood gas measurements in relation to characteristics of lung f unction and the influence of different CFTR genotype upon this process. Methods: Serial annual measurements of Pa assessed in relation to lung function, O 2 and PaCO 2 providing functional residual capacity (FRC pleth ), lung clearance index (LCI), trapped gas (V TG ), airway resistance (sR eff ), and forced expiratory indices (FEV 1 , FEF 50 ), were collected in 178 children (88 males; 90 females) with CF, over an age range of 5 to 18 years. Linear mixed model analysis and binary logistic regression anal ysis were used to define pred ominant lung function parameters influencing oxygenation and carbon dioxide elimination. Results: PaO 2 decreased linearly from age 5 to 18 year s, and was mainly associated with FRC pleth , ( p < 0.0001), FEV 1 ( p < 0.001), FEF 50 ( p < 0.002), and LCI ( p < 0.002), indicating that oxygenation was associated with the degree of pulmonary hyperinflation, ventilation inhomogeneities and impeded airway function. PaCO 2 showed a transitory phase of low PaCO 2 values, mainly during the age range of 5 to 12 years. Both PaO 2 and PaCO 2 presented with different progression slopes  within specific CFTR genotypes. Conclusion: In the long-term evaluation of gas exchan ge characteristics, an association with different lung function patterns was found and was clos ely related to specific genotypes. Early examination of blood gases may reveal hypo carbia, presumably reflecting compensatory mechanisms to improve oxygenation.

Published: 12 November 2009 Received: 4 August 2009 Respiratory Research 2009, 10 :106 doi:10.1186/1465-9921-10-106  Accepted: 12 November 2009 This article is available from: http://r espiratory-research.com/content/10/1/106 © 2009 Kraemer et al; licen see BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons. org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the orig inal work is properly cited.

Respiratory Research

Address: 1 Department of Paediatrics, University of Be rne, Inselspital CH-3010 Berne, Switzerland, 2 Division of Paediatric Respiratory Medicine, Department of Paediatrics, University of Be rne, Inselspital, CH-3010 Berne, Switzerland, 3 Division of Human Genetics, Department of Clinical Research, University of Berne, CH-3010 Berne. Switzerland and 4 Institute of Psychology, University of Berne, Muesmattstr. 45, CH-3000 Bern Switzerland Email: Richard Kraemer* - richard.kr [e-mail]; Philipp Latzin - philipp.latzin@ins el.ch; Isabelle Pramana - isabelle.pramana@insel. ch; Pietro Ballinari - [e-mail]; Sabina Gall ati - [e-mail]; Urs Frey - [e-mail] * Corresponding author

Research Open Access Long-term gas exchange characterist ics as markers of deterioration in patients with cystic fibrosis Richard Kraemer* 1 , Philipp Latzin 1,2 , Isabelle Pramana 1,2 , Pietro Ballinari 4 , Sabina Gallati 1,3 and Urs Frey 1,2