Related Experiment Videos
Absent hypoxic and hypercapneic arousal responses in children with myelomeningocele and apnea
Insights
Infants with myelomeningocele and Arnold-Chiari malformation show impaired arousal responses to low oxygen and high carbon dioxide levels during sleep. These deficits may contribute to breathing problems and poorer outcomes in affected infants.
Area of Science:
- Pediatric Neurology
- Respiratory Physiology
- Developmental Neuroscience
Background:
- Myelomeningocele and Arnold-Chiari malformation can affect brainstem function.
- Apnea and hypoventilation are common complications in infants with these conditions.
- Arousal from sleep is a critical protective mechanism against respiratory compromise.
Purpose of the Study:
- To investigate hypoxic and hypercapneic arousal responses in infants with myelomeningocele and Arnold-Chiari malformation.
- To compare these responses to those of healthy control infants.
- To determine if arousal deficits are present in this vulnerable infant population.
Main Methods:
- Seven infants with myelomeningocele and symptomatic apnea/hypoventilation were studied.
- Nine healthy infants served as controls.
- Hypoxic arousal was tested by decreasing inspired oxygen (PO2) to an end-tidal PO2 of 45 mm Hg.
- Hypercapneic arousal was tested by increasing inspired carbon dioxide (PCO2) to an end-tidal PCO2 of 60 mm Hg.
Main Results:
- Only 18.2% of infants with myelomeningocele aroused to hypoxia, compared to 89% of controls.
- 37.5% of infants with myelomeningocele aroused to hypercapnea, compared to 100% of controls.
- Three infants with myelomeningocele died during the study period.
Conclusions:
- Infants with myelomeningocele, Arnold-Chiari malformation, and apnea/hypoventilation exhibit significant arousal deficits.
- These arousal deficits represent a failure to respond to respiratory challenges.
- The findings highlight a critical vulnerability in cardiorespiratory regulation in these infants.
Abstract:
Hypoxic and hypercapneic arousal responses from quiet sleep were tested in seven infants with myelomeningocele and Arnold-Chiari malformation who were symptomatic with apnea and/or hypoventilation. All infants with myelomeningocele required tracheostomy and posterior fossa decompression. Responses were compared with those of nine healthy control infants. To assess hypoxic arousal, inspired PO2 was decreased until the end-tidal (alveolar) PO2 reached 45 mm Hg for a maximum of three minutes. Eleven studies were performed in seven infants with myelomeningocele, and arousal occurred in only two studies (18.2%). Eight of nine control infants aroused to hypoxia (89%). To test hypercapneic arousal, inspired PCO2 was increased until end-tidal PCO2 reached 60 mm Hg for a maximum of three minutes. Eight studies were performed on six infants with myelomeningocele, and arousal occurred in three studies (37.5%). All seven control infants studied aroused to hypercapnea (100%). Three infants with myelomeningocele subsequently died. Infants with myelomeningocele, Arnold-Chiari malformation, and apnea or hypoventilation have arousal deficits to respiratory stimuli.