Abstract
Rationale: Infants of mothers who smoked (S) or substance misused (SM) during pregnancy have an increased risk of sudden infant death syndrome (SIDS).
Objectives: To test the hypothesis that infants of S and SM mothers compared to infants of non substance misusing, non-smoking mothers (controls) would have a reduced ventilatory response to hypercarbia and that any reduction would be greater in the SM infants.
Methods: Infants were assessed before maternity/neonatal unit discharge. Maternal and infant urine samples were obtained and tested for cotinine, cannabinoids, opiates, amphetamines, methadone, cocaine and benzodiazepines.
Measurements and main results: Respiratory flow and tidal volume were measured using a pneumotachograph inserted into a face mask placed over the infant's mouth and nose. The ventilatory responses to three levels of inspired carbon dioxide (0% (baseline), 2% and 4% CO2) were assessed. Twenty-three SM, 34 S and 22 control infants were assessed. The birth weight of the controls was higher than the SM and S infants (p=0.017). At baseline, SM infants had a higher respiratory rate (p=0.003) and minute volume (p=0.007) compared to controls and S infants. Both the SM and S infants had a lower ventilatory response to 2% (p<0.001) and 4% (p<0.001) CO2 than the controls. The ventilatory response to CO2 was lower in the SM infants compared to the S infants (p=0.009).
Conclusions: These results are consistent with infants of smoking mothers and substance misuse/smoking mothers having a dampened ventilatory response to hypercarbia, which is particularly marked in the latter group.
Objectives: To test the hypothesis that infants of S and SM mothers compared to infants of non substance misusing, non-smoking mothers (controls) would have a reduced ventilatory response to hypercarbia and that any reduction would be greater in the SM infants.
Methods: Infants were assessed before maternity/neonatal unit discharge. Maternal and infant urine samples were obtained and tested for cotinine, cannabinoids, opiates, amphetamines, methadone, cocaine and benzodiazepines.
Measurements and main results: Respiratory flow and tidal volume were measured using a pneumotachograph inserted into a face mask placed over the infant's mouth and nose. The ventilatory responses to three levels of inspired carbon dioxide (0% (baseline), 2% and 4% CO2) were assessed. Twenty-three SM, 34 S and 22 control infants were assessed. The birth weight of the controls was higher than the SM and S infants (p=0.017). At baseline, SM infants had a higher respiratory rate (p=0.003) and minute volume (p=0.007) compared to controls and S infants. Both the SM and S infants had a lower ventilatory response to 2% (p<0.001) and 4% (p<0.001) CO2 than the controls. The ventilatory response to CO2 was lower in the SM infants compared to the S infants (p=0.009).
Conclusions: These results are consistent with infants of smoking mothers and substance misuse/smoking mothers having a dampened ventilatory response to hypercarbia, which is particularly marked in the latter group.
| Original language | English |
|---|---|
| Pages (from-to) | 933-938 |
| Number of pages | 6 |
| Journal | Annals of the American Thoracic Society |
| Volume | 11 |
| Issue number | 6 |
| DOIs | |
| Publication status | Published - Jul 2014 |
