Effetto di carichi elastici non uniformi sulle caratteristiche del respiro di soggetti anestetizzati e svegli

Agostoni, Emilio ; D'Angelo, Edgardo ; Torri, Giorgio ; Ravenna, Linda

Atti della Accademia Nazionale dei Lincei. Classe di Scienze Fisiche, Matematiche e Naturali. Rendiconti, Tome 60 (1976), p. 513-516 / Harvested from Biblioteca Digitale Italiana di Matematica

Résumé

In anesthetized subjects rib cage strapping (RCS) did not change tidal volume ($V_{T}$) and increased ventilation ($\dot{V}$), whereas abdomen strapping (AS) decreased markedly $V_{T}$ and $\dot{V}$. Both kinds of strapping decreased expiratory duration ($T_{E}$), but did not change inspiratory duration ($T_{I}$) and breathing rate. RCS and AS decreased lung volume by about 200 ml and increased the elastance of the respiratory system by 12 cm $H_{2}O/l$ and 9 cm $H_{2}O/l$, respectively. The changes produced are mainly due to mechanical factors, though reflexes seem to be also operating in some cases. In conscious subjects RCS decreased $V_{T}$, $T_{I}$, $T_{E}$ and did not change $\dot{V}$, whereas AS did not change these parameters. The different changes in conscious and anesthetized subjects show the effects of cortical influences, which explain also in part the different effect elicited in conscious subjects by RCS and AS. The effects produced by RCS are mainly due to the sensation of hindrance to rib cage expansion, rather than to that of rib cage sqeezing, as shown by experiments of RCS without reduction of rib cage volume.

Détail

Publié le : 1976-11-01

Bibliographie

Agostoni, E. (1970) - Kinematics. In: The Respiratory Muscles, Mechanics and Neural Control (E. J. M. Campbell, E. Agostoni and J. Newson Davis, Editors). Lloyd-Luke, London.

Bland, S., Lazerou, L., Dyck, G. e Cherniack, R. M. (1967) - The influence of the «chest wall» on respiratory rate and depth, «Respir. Physiol.», 3, 47-54.

Cambell, E. J. M., Dinnick, D. T. e Howell, J. B. L. (1961) - The immediate effects of elastic loads on the breathing of man, «J. Physiol. (London)», 156, 260-273.

Caro, C. G., Butler, J. e Du Bois, A. B. (1960) - Some effects of restrictions of chest cage expansion on pulmonary function in man: an experimental study, «J. Clin. Invest.», 39, 753-583.

Freedman, S. e Weinstein, S. A. (1966) - Effects of external elastic and threshold loading on breathing in man, «J. Appl. Physiol.», 20, 449-472.

Margaria, C. E., Iscoe, S., Pengelly, L. D., Couture, J., Don, H. e Milic-Emili, J. (1973) - Immediate ventilatory response to elastic loads and positive pressure in man, «Respir. Physiol.», 18, 347-369.

Mcilroy, N. B., Butler, J. e Finley, T. N. (1962) - Effects of chest compression on reflex ventilatory drive and pulmonary function, «J. Appl. Physiol.», 17, 701-705.