TY - JOUR
T1 - Effect of oxygen and of carbon dioxide tension on the incidence of apnea in fetal lambs
AU - Bissonnette, John M.
AU - Hohimer, A. Roger
AU - Cronan, James Z.
AU - Paul, Marilyn S.
N1 - Funding Information:
This work was supported by Grants HD 00134, HD 11251, and HL 05711 from the United States Public Health Service.
PY - 1980
Y1 - 1980
N2 - Fetal breathing movements (FBM) in unanesthetized lambs in utero were correlated with measurements of arterial blood gases. One hundred and eighty-seven observations, consisting of the incidence of FBM during the hour preceding and the hour after the blood gas determinations, were made on 125 separate days in 30 fetuses of 117 to 146 days' gestational age. Fifty-eight percent of the observations with fetal apnea (FBM 0 to 9% in 2 hours) showed hypoxia (PaO2 ≤ 16 torr), whereas only 4% of the observations with FBM greater than 10% were associated with hypoxia. Seventy-eight percent of the hypoxic and normocarbic (PaCO2 42 to 53 torr) observations demonstrated apnea. However, only 44% of hypoxic plus hypercarbic (PaCO2 57 to 63 torr) fetuses were apneic, and with an elevated PaCO2, apnea tended to develop at a lower level of PaO2. We conclude that FBM may persist in the presence of hypercarbia with hypoxia.
AB - Fetal breathing movements (FBM) in unanesthetized lambs in utero were correlated with measurements of arterial blood gases. One hundred and eighty-seven observations, consisting of the incidence of FBM during the hour preceding and the hour after the blood gas determinations, were made on 125 separate days in 30 fetuses of 117 to 146 days' gestational age. Fifty-eight percent of the observations with fetal apnea (FBM 0 to 9% in 2 hours) showed hypoxia (PaO2 ≤ 16 torr), whereas only 4% of the observations with FBM greater than 10% were associated with hypoxia. Seventy-eight percent of the hypoxic and normocarbic (PaCO2 42 to 53 torr) observations demonstrated apnea. However, only 44% of hypoxic plus hypercarbic (PaCO2 57 to 63 torr) fetuses were apneic, and with an elevated PaCO2, apnea tended to develop at a lower level of PaO2. We conclude that FBM may persist in the presence of hypercarbia with hypoxia.
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U2 - 10.1016/0002-9378(80)90698-5
DO - 10.1016/0002-9378(80)90698-5
M3 - Article
C2 - 6770689
AN - SCOPUS:0018959289
SN - 0002-9378
VL - 137
SP - 575
EP - 578
JO - American Journal of Obstetrics and Gynecology
JF - American Journal of Obstetrics and Gynecology
IS - 5
ER -