Abstract
Aspiration is common and often complicates recovery from ventilator therapy in the neonate. The object of this study was to examine the upper airway sites which determine the respiratory responses to an irritant challenge. Twelve lambs were studied awake at a mean postnatal age of 26 days and with a mean weight of 6.7kg. Via a tracheostomy (Ty) and system of balloons, it was possible to instill selectively 1 ml of S, or CA, onto firstly only the mid-tracheal area (MT), secondly only the laryngeal area (LA) and thirdly only the lower tracheal area (LT). During the studies spontaneous breathing occurred via an endotracheal tube placed in the Ty. Minute ventilation (VE), recorded as changes from baseline, was measured at 30 seconds (s), 1 and 2 minutes (m), after the challenge. Arterial blood gas changes were measured at 30s and 2m. Significant increases in VE resulted only when either S or CA were given into the LT. The mean CA increase at 30s was significantly greater than the S one (587 v 78 ml/kg/min). A lesser difference persisted at 1 and 2 m. After LT S PaO2, fell at 30s (-8mmHg) and at 2 m (-9mnHg). At 30s and 2m LT CA resulted in a rise in pH (0.08; 0.02), ll in PaCO2 (-7mmHg; -4mmHg) and no changes in BE. At 30s an 2m LA CA caused a fall in PaO2 (-14mmHg; -10mmHg) while LT CA caused a rise in PaO2 at 30s (16mmHg) and a fall at 2m (-3mmHg). The response to an irritant challenge in the airway consistently resulted in increased ventilation only when the lower tracheal site was stimulated but delayed hypoxemia occurred. The laryngeal site VE response was inconsistent but associated with significant hypoxemia. The mid-tracheal site response was minimal.
Article PDF
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Hutchison, A., Reyes, L., Evans, S. et al. 1418 EFFECT OF AIRWAY CITRIC ACID (CA) AND SALINE (S) UPON VENTILATION AND BLOOD GASES IN NEWBORN LAMBS. Pediatr Res 19, 347 (1985). https://doi.org/10.1203/00006450-198504000-01442
Issue Date:
DOI: https://doi.org/10.1203/00006450-198504000-01442