Biomedical subjects

Patricia Galster

Publications and source records attributed to Patricia Galster.

4 recordsLinked to original sources

PubMed2004

Upper airway dynamic responses in children with the obstructive sleep apnea syndrome.

Normal children have a smaller upper airway than adults, but, nevertheless, snore less and have less apnea. We have previously shown that normal children have an upper airway that is resistant to collapse during sleep. We hypothesized that this resistance to collapse is due to preservation of upper airway neuromotor responses during sleep. Furthermore, we hypothesized that upper airway responses would be diminished in children with the obstructive sleep apnea syndrome (OSAS). We therefore compared the upper airway pressure-flow relationship during sleep between children with OSAS and controls. Measurements were made by correlating maximal inspiratory airflow with the level of nasal pressure applied via a mask. Neuromotor upper airway activation was assessed by evaluating the upper airway response to 1) hypercapnia and 2) intermittent, acute negative pressure. We found that children with OSAS had no significant response to either hypercapnia or negative pressure during sleep, compared with the normal children. After treatment of OSAS by tonsillectomy and adenoidectomy, there was a trend for normalization of upper airway responses. We conclude that upper airway dynamic responses are decreased in children with OSAS but recover after treatment. We speculate that the pharyngeal airway neuromotor responses present in normal children are a compensatory response for a relatively narrow upper airway. Further, we speculate that this compensatory response is lacking in children with OSAS, most likely due to either habituation to chronic respiratory abnormalities during sleep or to mechanical damage to the upper airway.

Adenoidectomy↗

PubMed2004

Reliability of scoring arousals in normal children and children with obstructive sleep apnea syndrome.

STUDY OBJECTIVES: Scoring of arousals in children is based on an extension of adult criteria, as defined by the American Sleep Disorders Association (ASDA). By this, a minimum duration of 3 seconds is required. A few recent studies utilized modified criteria for the study of children, with durations as short as 1 second. However, the validity and reliability of scoring these shorter arousals have never been verified. Based on studies in adults, we hypothesized that interscorer agreement for scoring arousals shorter than 3 seconds was poor. DESIGN: Retrospective review of polysomnograms by 2 experienced sleep practitioners who independently scored arousals according to the ASDA 3-second criteria and modified duration criteria of 1 and 2 seconds. SETTING: Academic hospital. PATIENTS OR PARTICIPANTS: 20 polysomnographic studies from children aged 3 to 8 years with mild to severe obstructive sleep apnea syndrome, and 16 polysomnographic studies from normal children. INTERVENTIONS: None. MEASUREMENTS AND RESULTS: The intraclass correlation coefficient for scoring ASDA arousals was 0.90 (95% confidence interval: 0.81-0.95), indicating excellent interscorer agreement. The intraclass correlation coefficient for scoring modified 1-second and 2-second arousals were 0.35 (95% confidence interval: 0.02-0.61) and 0.42 (95% confidence interval: 0.12-0.65) respectively, indicating poor to fair interscorer agreement. Furthermore, modified 1-second and 2-second arousals accounted for less than 15% of all arousals scored. CONCLUSIONS: We conclude that there is much poorer interscorer agreement for scoring arousals shorter than 3 seconds, when compared to the standard ASDA criteria. We propose that scoring of arousals in children should follow the standard ASDA criteria.

Arousal↗

PubMed2004

Developmental changes in upper airway dynamics.

Normal children have a less collapsible upper airway in response to subatmospheric pressure administration (P(NEG)) during sleep than normal adults do, and this upper airway response appears to be modulated by the central ventilatory drive. Children have a greater ventilatory drive than adults. We, therefore, hypothesized that children have increased neuromotor activation of their pharyngeal airway during sleep compared with adults. As infants have few obstructive apneas during sleep, we hypothesized that infants would have an upper airway that was resistant to collapse. We, therefore, compared the upper airway pressure-flow (V) relationship during sleep between normal infants, prepubertal children, and adults. We evaluated the upper airway response to 1). intermittent, acute P(NEG) (infants, children, and adults), and 2). hypercapnia (children and adults). We found that adults had a more collapsible upper airway during sleep than either infants or children. The children exhibited a vigorous response to both P(NEG) and hypercapnia during sleep (P < 0.01), whereas adults had no significant change. Infants had an airway that was resistant to collapse and showed a very rapid response to P(NEG). We conclude that the upper airway is resistant to collapse during sleep in infants and children. Normal children have preservation of upper airway responses to P(NEG) and hypercapnia during sleep, whereas responses are diminished in adults. Infants appear to have a different pattern of upper airway activation than older children. We speculate that the pharyngeal airway responses present in normal children are a compensatory response for a relatively narrow upper airway.

Adolescent↗

PubMed2002

Night-to-night variability of polysomnography in children with suspected obstructive sleep apnea.

OBJECTIVES: To determine whether a single polysomnographic night was a valid measure of obstructive sleep apnea syndrome (OSAS) in children with symptoms of sleep-disordered breathing. STUDY DESIGN: The night-to-night variability of respiratory and sleep parameters was measured prospectively in 30 snoring children aged 1.6 to 11.3 years (mean +/- SD, 4.1 +/- 2) by using 2 nocturnal polysomnograms performed 7 to 27 days apart (14 +/- 5 days). RESULTS: The mean of the respiratory variables including apnea index, apnea/hypopnea index, arterial oxygen saturation, and end-tidal partial pressure of carbon dioxide were not significantly different from night to night. Among the sleep parameters, there was no significant night-to-night difference in sleep efficiency, arousal index, percent rapid eye movement, or percent of slow wave sleep. Only the percentage of stage 2 was significantly different between the nights. The polysomnographic clinical diagnosis remained the same on both nights for all children, although the disease severity differed slightly in 2 patients. CONCLUSIONS: There is little clinically significant night-to-night variability in pediatric polysomnography, and no first-night effect. These data suggest that a single polysomnographic night is an adequate measure of the OSAS in children with symptoms of sleep-disordered breathing.

Child↗