BACKGROUND:We tested the hypothesis that ventilatory drive in hypoxia and hypercapnia is inversely correlated with the number of hypopneas and obstructive apneas per hour of sleep (obstructive apnea hypopnea index, OAHI) in children.METHODS:Fifty children, 6 to 12 years of age were studied. Participants had an in-home unattended polysomnogram to compute the OAHI. We subsequently estimated ventilatory drive in normoxia, at two levels of isocapnic hypoxia, and at three levels of hyperoxic hypercapnia in each subject. Experiments were done during wakefulness, and the mouth occlusion pressure measured 0.1 seconds after inspiratory onset (P0.1) was measured in all conditions. The slope of the relation between P0.1 and the partial pressure of end-tidal O2 or CO2 (PETO2 and PETCO2) served as the index of hypoxic or hypercapnic ventilatory drive.RESULTS:Hypoxic ventilatory drive correlated inversely with OAHI (r = -0.31, P = 0.041), but the hypercapnic ventilatory drive did not (r = -0.19, P = 0.27). We also found that the resting PETCO2 was significantly and positively correlated with the OAHI, suggesting that high OAHI values were associated with resting CO2 retention.CONCLUSIONS:In awake children the OAHI correlates inversely with the hypoxic ventilatory drive and positively with the resting PETCO2. Whether or not diminished hypoxic drive or resting CO2 retention while awake can explain the severity of sleep-disordered breathing in this population is uncertain, but a reduced hypoxic ventilatory drive and resting CO2 retention are associated with sleep-disordered breathing in 6-12 year old children.
| Identifer | oai:union.ndltd.org:arizona.edu/oai:arizona.openrepository.com:10150/610096 |
| Date | January 2004 |
| Creators | Fregosi, Ralph, Quan, Stuart, Jackson, Andrew, Kaemingk, Kris, Morgan, Wayne, Goodwin, Jamie, Reeder, Jenny, Cabrera, Rosaria, Antonio, Elena |
| Contributors | Department of Physiology, The University of Arizona, Tucson, USA, Arizona Respiratory Center, The University of Arizona, Tucson, USA, Steele Memorial Children's Research Center, The University of Arizona, Tucson, USA, Department of Pediatrics, The University of Arizona, Tucson, USA, Department of Medicine, The University of Arizona, Tucson, USA, Department of Biomedical Engineering, Boston University, Boston, USA |
| Publisher | BioMed Central |
| Source Sets | University of Arizona |
| Language | English |
| Detected Language | English |
| Type | Article |
| Rights | © 2004 Fregosi et al; licensee BioMed Central Ltd. This is an Open Access article: verbatim copying and redistribution of this article are permitted in all media for any purpose, provided this notice is preserved along with the article's original URL. |
| Relation | http://www.biomedcentral.com/1471-2466/4/4 |
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