Article

Normative data for pH of exhaled breath condensate

Division of Neonatology, Department of Pediatrics, University of Virginia, Charlottesville, VA 22908, USA.
Chest (Impact Factor: 7.13). 03/2006; 129(2):426-30. DOI: 10.1378/chest.129.2.426
Source: PubMed

ABSTRACT Measurement of pH is one of the simplest and most technically validated biomarkers studied in exhaled breath condensate (EBC). The pH of EBC has been found to be lower than controls in many respiratory disorders. Published data from normal control subjects have been reasonably consistent, but the data sets are not large. This study was undertaken to establish normative EBC pH reference values.
Four hundred four healthy subjects of all ages were enrolled.
Each participant provided a single EBC sample using a disposable collector at modest temperature so that EBC was collected as a liquid.
Samples of EBC were bubbled with argon gas to standardize for carbon dioxide, and pH was recorded with a calibrated and validated glass microelectrode on stabilization. The median EBC pH was 8.0 with interquartile (25 to 75%) range of 7.8 to 8.1. There were no differences based on age, sex, or race. The distribution is skewed, with 6.4% of EBC samples having a pH range < 7.4.
An extensive normal data set now exists that reveals EBC pH is maintained in a modestly alkaline and tight range in subjects who consider themselves healthy.

Download full-text

Full-text

Available from: Dorothy Bunyan, Aug 06, 2015
1 Follower
 · 
136 Views
  • Source
    • "Acidification occurs in several respiratory diseases (Borrill et al., 2008; Hunt, 2007; Horvarth et al., 2005). The level of EBC pH is unaffected by variables that include subject age, race, gender, collecting and storage temperature, acute airway obstruction, ammonia in the mouth, saliva pH, hyperand hypoventilation (Bloemen et al., 2007; Paget-Brown et al., 2006; Borrill et al., 2005; Wells et al., 2005; Vaughan et al., 2003). Acidification of EBC occurs in acidic materials generated from inflammatory cells (Hunt et al., 2002), and gastroesophageal reflux (Effros et al., 2005). "
    [Show abstract] [Hide abstract]
    ABSTRACT: Inhaled inorganic dusts, such as coal, can cause inflammation and fibrosis in the lungs, known as pneumoconiosis. Diagnosis of pneumoconiosis depends on morphological changes by radiological findings and functional change by pulmonary function test (PFT) . Unfortunately, current diagnostic findings are limited only to lung fibrosis, which is usually irreversibly progressive. Therefore, it is important that research on potential and prospective biomarkers for pneumoconiosis should be conducted prior to initiation of irreversible radiological or functional changes in the lungs. Analytical techniques using exhaled breath condensate (EBC) or exhaled gas are non-invasive methods for detection of various respiratory diseases. The objective of this study is to investigate the relationship between inflammatory biomarkers, such as EBC pH or fractional exhaled nitric oxide (FENO) , and pneumoconiosis among 120 retired coal miners (41 controls and 79 pneumoconiosis patients) . Levels of EBC pH and FENO did not show a statistically significant difference between the pneumoconiosis patient group and pneumoconiosis patients with small opacity classified by International Labor Organization (ILO) classification. The mean concentration of FENO in the low percentage FEV1 (< 80%) was lower than that in the high percentage (80% ≤) (p = 0.023) . The mean concentration of FENO in current smokers was lower than that in non smokers (never or past smokers) (p = 0.027) . Although there was no statistical significance, the levels of FENO in smokers tended to decrease, compared with non smokers, regardless of pneumoconiosis. In conclusion, there was no significant relationship between the level of EBC pH or FENO and radiological findings or PFT. The effects between exhaled biomarkers and pneumoconiosis progression, such as decreasing PFT and exacerbation of radiological findings, should be monitored.
    12/2010; 26(4):329-337. DOI:10.5487/TR.2010.26.4.329
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: In recent years, the analysis of exhaled breath condensate samples has been given great weight as a noninvasive methodology of studying physiology and lung diseases. The present study describes a device for measuring exhaled breath condensate that is affordable, easily constructed, portable and suitable for use in the field, as well as allowing the collection of simultaneous samples. The results obtained with this device in terms of the concentrations of pH, hydrogen peroxide and nitrite, metabolites related to inflammatory and oxidative damage, in exhaled breath condensate samples are comparable to those obtained with other devices previously described.
  • [Show abstract] [Hide abstract]
    ABSTRACT: A new approach for improving the yield of large area MOS-gated power devices is described based upon wafer repair using fusible links of aluminum or polysilicon to isolate defective segments from the rest of the device. Unlike previously reported wafer repair techniques, the proposed approach does not require any knowledge of the location of the fault (gate-to-source short) within the device. Work done on the development of power-MOS process compatible fusible links is described in this paper. Power MOSFET's and IGBT's have been successfully fabricated using these fusible links to perform wafer repair
    IEEE Transactions on Electron Devices 03/1996; DOI:10.1109/16.481738 · 2.36 Impact Factor
Show more