Lack of the mechanoreceptor influences on ventilatory control during halothane anesthesia in humans
- 21 Downloads
Mechanical influences independent of chemoreceptor function on ventilatory control were studied in halothane-anesthetized, artificially ventilated patients using the technique reported by Altose et al. (Respir Physiol 66: 171–180, 1986). Contribution of mechanical factor was indirectly assessed by comparing the values of arterial carbon dioxide tension at which the subjects started breathing efforts during CO2 loading induced by the following two methods. 1) Partial rebreathing of expired gas and 2) Mechanical hypoventilation (successive decrease in inflation volume). These two maneuvers resulted in a similar rate of increase in end-expiratory carbon dioxide tension. However, contrary to the observation made by Altose et al. in awake volunteers, we found comparable values of ventilatory recruitment threshold for PaCO 2. Thus, we speculate that halothane anesthesia and/or loss of consciousness impair transmission of afferent information from the lung and/or chest wall musculature. Such effects may be responsible for the depression of load compensatory mechanism during anesthesia.
Key wordshalothane ventilatory recruitment threshold carbon dioxide tension mechanoreceptor afferent
Unable to display preview. Download preview PDF.
- 5.Remmers JE, Tsiaras WG: Effects of lateral cervical cord lesions on the respiratory rhythm of anesthetized decerebrated cats after vagotomy. J Physiol (Lond) 233:63–74, 1973Google Scholar
- 6.Jamme Y, Buchler B, Delpierre S, et al: Phrenic afferents and their role in inspiratory control. J Appl Physiol 60:854–860, 1986Google Scholar
- 7.Duron B: Intercostal and diaphragmatic muscle endings and afferents. In: Hornbein TF eds. Regulation of Breathing, part I. Lung Biology in Health and Disease vol. 17. New York, Marcel Dekker 473–540, 1981Google Scholar
- 8.Duron B: La fonction respiratoire pendant Ie sommeil physiologique. Bull Physiol PathoI Respir 8:1031–1057, 1972Google Scholar
- 9.Prechter GC, Nelson SB, Hubmayr RD: The ventilatory recruitment threshold for carbon dioxide. Am Rev Repir Dis 141:758–764, 1990Google Scholar