The ventilatory response to carbon dioxide in high risk infants.
OBJECTIVE
To examine the ventilatory response to inspired carbon dioxide in infants considered to be at risk for sudden infant death syndrome or apnea.


METHODS
Clinical data measurement.


METHODS
Infant apnea evaluation program of a university division of neonatology.


METHODS
Fifty nine infants were full term characterized by the following diagnoses; siblings of infants who had died from sudden infant death syndrome (SIDS) (n = 7), apparent life threatening event (ALTE) (n = 24), apnea/cyanosis in the newborn nursery (n = 21), and controls. Sixty-nine infants were preterm and consisted of patients suffering from idiopathic apnea (n = 61), and bronchopulmonary dysplasia (n = 8).


METHODS
The ventilatory response to carbon dioxide was measured with a computerized waveform analyzer.


RESULTS
Among full term infants no significant differences in the ventilatory slope in response to CO2 was seen. The range of mean slope was 19.4 +/- 7.6 in siblings of SIDS and 36 +/- 17 in control infants. Greater number of sibling of SIDS had slopes less than 20 ml/kg/min/mmHg in comparison to control infants. Sibling of SIDS had less increase in minute ventilation and inspiratory flow in response to CO2 administration in comparison to control infants. Preterm infants had similar slopes with a mean of 33 ml/kg/min/mmHg in infants with idiopathic apnea and 28 ml/kg/min/mmHg in infants with bronchopulmonary dysplasia.


CONCLUSIONS
The large intragroup variability in the ventilatory response to inspired CO2, confirming previously reported data, comprises the benefit of this test. Thus, ventilatory response to CO2 administration is not useful in unselected patients at risk of SIDS or apnea.
Anwar
M
M
Department of Pediatrics, UMDNJ-Robert Wood Johnson Medical School, St. Peter's Medical Center, New Brunswick 08903.
Marotta
F
F
Fort
M D
MD
Mondestin
H
H
Mojica
C
C
Walsh
S
S
Hiatt
M
M
Hegyi
T
T
D001049:Apnea / Q000503:physiopathology*; D001997:Bronchopulmonary Dysplasia / Q000503:physiopathology*; D002245:Carbon Dioxide / Q000008:administration & dosage / Q000494:pharmacology*; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature / Q000502:physiology*; D012119:Respiration / Q000187:drug effects*; D012307:Risk Factors; D013398:Sudden Infant Death / Q000235:genetics
D002245:Carbon Dioxide