Speed and Profile of the Arterial Peripheral Chemoreceptors as Measured by Ventilatory Changes in Preterm Infants
| Autor: | Z. Weintraub, Donald B. Cates, Kim Kwiatkowski, Henrique Rigatto, Ruben Alvaro |
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| Rok vydání: | 1992 |
| Předmět: |
Inhalation
business.industry Respiration Infant Newborn Peripheral chemoreceptors Apnea Gestational age Arteries Chemoreceptor Cells Hypoventilation Oxygen Anesthesia Pediatrics Perinatology and Child Health medicine Breathing Humans medicine.symptom business Infant Premature Tidal volume Respiratory minute volume |
| Zdroj: | Pediatric Research. 32:226-229 |
| ISSN: | 1530-0447 0031-3998 |
| DOI: | 10.1203/00006450-199208000-00020 |
| Popis: | To measure the response time of the peripheral chemoreceptors, we studied 13 preterm infants [birth weight 1602 ± 230 g (mean ± SEM); gestational age 31 ± 1 wk; postnatal age 15 ± 1 d] during inhalation of 21% O2 (15 ± 5 s) followed by 100% O2 (1 min). We used a flow-through system to measure ventilation and gas analyzers to measure alveolar gases. Hypoventilation was observed at 3.6 ± 0.6 s and was maximal at 6.8 ± 1 s after O2 began. This maximal response was always associated with an apnea (>3 s). Alveolar Po2 increased from 13.5 ± 0.1 kPa (101 ± 0.8 torr) (control) to 28.0 1.2 kPa (210 ± 9 torr) (1st O2 breath), to 42.0 ± 2.4 kPa (315 ± 18 torr) (1st hypoventilation), to 45.9 ± 4.1 kPa (344 ± 31 torr) (breath preceding maximal response), and to 53.6 ± 4.1 kPa (402 ± 31 torr) (at maximal response). Minute ventilation was 0.192 ± 0.011 (control), 0.188 ± 0.011 (1st O2 breath), 0.088 ± 0.016 (1st hypoventilation; p < 0.0001), 0.122 ± 0.016 (breath preceding maximal response; p < 0.0002), and 0.044 ± 0.011 L/min/kg at maximal response (p < 0.0001). This decrease in ventilation was due to a decrease in frequency with no appreciable change in tidal volume. The initial period of hypoventilation (19 ± 4 s) was followed by a breathing interval (10 ± 2 s) and a second period of hypoventilation (14 ± 3 s) before continuous breathing resumed. These findings suggest that the peripheral chemoreceptors in these infants have a high baseline activity and a fast response time. |
| Databáze: | OpenAIRE |
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