Abstract
BACKGROUND: Unexplained or primary pulmonary hypertension results in an obliteration and obstruction of resistance pulmonary arteries. In these patients gas exchange is impaired and the measurement of gas transfer for carbon monoxide is usually reduced. This has been thought to represent a reduction in pulmonary alveolar capillary blood volume (Vc). A single breath test, measuring simultaneously the uptake of both nitric oxide (NO) and carbon monoxide (CO), provides a simple and practical measurement of membrane diffusion (Dm) and Vc. METHODS: A standard single breath test for the measurement of gas transfer for carbon monoxide (TLCO) was adapted to include NO (40 ppm) in the inhaled gas mixture and a breath-hold time at total lung capacity of 7.5 seconds was used. Twelve patients with primary pulmonary hypertension and 10 similar normal volunteers were studied while seated at rest. RESULTS: The patients had reduced values for TLCO and TLNO. The mean (SD) value of Dm in the patients was 36.7 (32.1) mmol/min.kPa compared with 52.8 (23.9) mmol/min.kPa in the normal subjects. Vc in the patients was 0.03 (0.03) 1 and 0.06 (0.01) 1 in the normal subjects. CONCLUSIONS: The simultaneous measurement of NO and CO uptake is possible in healthy volunteers and patients with primary hypertension. In these patients capillary blood volume is reduced compared with normal subjects.
Full text
PDFSelected References
These references are in PubMed. This may not be the complete list of references from this article.
- Bjornsson J., Edwards W. D. Primary pulmonary hypertension: a histopathologic study of 80 cases. Mayo Clin Proc. 1985 Jan;60(1):16–25. doi: 10.1016/s0025-6196(12)65277-x. [DOI] [PubMed] [Google Scholar]
- Borland C. D., Cox Y. Effect of varying alveolar oxygen partial pressure on diffusing capacity for nitric oxide and carbon monoxide, membrane diffusing capacity and lung capillary blood volume. Clin Sci (Lond) 1991 Dec;81(6):759–765. doi: 10.1042/cs0810759. [DOI] [PubMed] [Google Scholar]
- D'Alonzo G. E., Barst R. J., Ayres S. M., Bergofsky E. H., Brundage B. H., Detre K. M., Fishman A. P., Goldring R. M., Groves B. M., Kernis J. T. Survival in patients with primary pulmonary hypertension. Results from a national prospective registry. Ann Intern Med. 1991 Sep 1;115(5):343–349. doi: 10.7326/0003-4819-115-5-343. [DOI] [PubMed] [Google Scholar]
- Dantzker D. R., Bower J. S. Mechanisms of gas exchange abnormality in patients with chronic obliterative pulmonary vascular disease. J Clin Invest. 1979 Oct;64(4):1050–1055. doi: 10.1172/JCI109542. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Dantzker D. R., Bower J. S. Pulmonary vascular tone improves VA/Q matching in obliterative pulmonary hypertension. J Appl Physiol Respir Environ Exerc Physiol. 1981 Sep;51(3):607–613. doi: 10.1152/jappl.1981.51.3.607. [DOI] [PubMed] [Google Scholar]
- Davies N. J. Does the lung work? 4. What does the transfer of carbon monoxide mean? Br J Dis Chest. 1982 Apr;76(2):105–124. [PubMed] [Google Scholar]
- JONES N. L., GOODWIN J. F. RESPIRATORY FUNCTION IN PULMONARY THROMBOEMBOLIC DISORDERS. Br Med J. 1965 Apr 24;1(5442):1089–1093. doi: 10.1136/bmj.1.5442.1089. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Nadel J. A., Gold W. M., Burgess J. H. Early diagnosis of chronic pulmonary vascular obstruction. Value of pulmonary function tests. Am J Med. 1968 Jan;44(1):16–25. doi: 10.1016/0002-9343(68)90233-7. [DOI] [PubMed] [Google Scholar]
- Otulana B., Higenbottam T. The role of physiological deadspace and shunt in the gas exchange of patients with pulmonary hypertension: a study of exercise and prostacyclin infusion. Eur Respir J. 1988 Aug;1(8):732–737. [PubMed] [Google Scholar]
- Reeves J. T., Noonan J. A. Microarteriographic studies of primary pulmonary hypertension. A quantitative approach in two patients. Arch Pathol. 1973 Jan;95(1):50–55. [PubMed] [Google Scholar]
- Reid L. M. Structure and function in pulmonary hypertension. New perceptions. Chest. 1986 Feb;89(2):279–288. doi: 10.1378/chest.89.2.279. [DOI] [PubMed] [Google Scholar]
- Smith P., Heath D., Yacoub M., Madden B., Caslin A., Gosney J. The ultrastructure of plexogenic pulmonary arteriopathy. J Pathol. 1990 Feb;160(2):111–121. doi: 10.1002/path.1711600204. [DOI] [PubMed] [Google Scholar]