THE EFFECT OF CPAP ON THE EXPIRATORY BREATHING PATTERN IN PRETERM INFANTS
| Autor: | Peter Schaller, Hans-Jürgen Mädler, Andreas Schylze, Bieter Bayrok |
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| Rok vydání: | 1989 |
| Předmět: | |
| Zdroj: | Pediatric Research. 26:508-508 |
| ISSN: | 1530-0447 0031-3998 |
| DOI: | 10.1203/00006450-198911000-00053 |
| Popis: | The infant can defend or even elevate dynamically the functional residual capacity by additional respiratory muscles work: 1. early expiratory airflow(v) may be retarded by postinspiraton inspiratory muscle activity and/Dr laryngeal narrowing; 2. inspiration can start before expiration has been completed to the relaxation volume. To study the effect of CPAP on both phenomena, we elevated the airway pressure stepwise in 23 infants (BW 1746±417 g). A computerized bedside V-volume(V) technique was used for evaluation. In 16 “responders” early expiratory braking decreased and “preterm inspiratory interruption” was postponed at an appropriate CPAP. The linear segment (relaxation line) of the V-V-loop was lengthened with the expiratory time reaching a maximum. Elevation of CPAP beyond this level again produced a rapid, shallow pattern - often combined with V-acceleration late in expiration (recruitment of expiratory muscles). These latter signs of excessive airway pressure occured in the remaining 7 infants (nonresponders) already at the lowest CPAP-levels applied during the “titration trials”. Respiratory rate without CPAP was different between responders (84±17/min) and nonresponders (46±11). This approach to deciding the CPAP level might reduce the risk of respiratory muscle fatigue. |
| Databáze: | OpenAIRE |
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