Abstract
To investigate whether the supine posture caused sustained bronchoconstriction and could thus contribute to the development of nocturnal asthma, nine patients with nocturnal asthma were studied on two consecutive days, lying supine for four hours on one day and sitting upright for four hours on the other, the order of the two postures being randomised. Peak expiratory flow (PEF), forced expiratory volume in one second (FEV1), and forced vital capacity (FVC) were measured immediately before and after the four hours and over the subsequent hour. There was no significant difference between the erect and supine posture for PEF (248 v 248 l/min), FEV1 (1.31 v 1.22 l), or FVC (2.34 v 2.28 l) at the end of the four hours, nor did any significant change develop subsequently. Thus the supine posture is not associated with prolonged bronchoconstriction. As each patient had previously shown an average overnight fall in PEF of more than 20%, this study strongly suggests that the supine posture is not an important cause of overnight bronchoconstriction.
Full text
PDF![579](https://cdn.ncbi.nlm.nih.gov/pmc/blobs/5a11/461961/c9d97782ef9f/thorax00283-0053.png)
![580](https://cdn.ncbi.nlm.nih.gov/pmc/blobs/5a11/461961/a9b4f402c580/thorax00283-0054.png)
![581](https://cdn.ncbi.nlm.nih.gov/pmc/blobs/5a11/461961/72462f33255b/thorax00283-0055.png)
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Carpentiere G., Marino S., Castello F. Effects of inhaled fenoterol on the circadian rhythm of expiratory flow in allergic bronchial asthma. Chest. 1983 Feb;83(2):211–214. doi: 10.1378/chest.83.2.211. [DOI] [PubMed] [Google Scholar]
- Clark T. J., Hetzel M. R. Diurnal variation of asthma. Br J Dis Chest. 1977 Apr;71(2):87–92. doi: 10.1016/0007-0971(77)90087-0. [DOI] [PubMed] [Google Scholar]
- Coe C. I., Barnes P. J. Reduction of nocturnal asthma by an inhaled anticholinergic drug. Chest. 1986 Oct;90(4):485–488. doi: 10.1378/chest.90.4.485. [DOI] [PubMed] [Google Scholar]
- Douglas N. J. Asthma at night. Clin Chest Med. 1985 Dec;6(4):663–674. [PubMed] [Google Scholar]
- Douglas N. J., Calverley P. M., Leggett R. J., Brash H. M., Flenley D. C., Brezinova V. Transient hypoxaemia during sleep in chronic bronchitis and emphysema. Lancet. 1979 Jan 6;1(8106):1–4. doi: 10.1016/s0140-6736(79)90451-3. [DOI] [PubMed] [Google Scholar]
- Jönsson E., Mossberg B. Impairment of ventilatory function by supine posture in asthma. Eur J Respir Dis. 1984 Oct;65(7):496–503. [PubMed] [Google Scholar]
- Morrison J. F., Pearson S. B., Dean H. G. Parasympathetic nervous system in nocturnal asthma. Br Med J (Clin Res Ed) 1988 May 21;296(6634):1427–1429. doi: 10.1136/bmj.296.6634.1427. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Mossberg B., Larsson K. Effect of sleep deprivation on overnight bronchoconstriction in nocturnal asthma. Thorax. 1987 Apr;42(4):319–319. doi: 10.1136/thx.42.4.319. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Turner-Warwick M. On observing patterns of airflow obstruction in chronic asthma. Br J Dis Chest. 1977 Apr;71(2):73–86. doi: 10.1016/0007-0971(77)90086-9. [DOI] [PubMed] [Google Scholar]