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Oxygen therapy for intrauterine growth retardation
Aerobic and anaerobic faecal cultures were performed on 27 normal full-term infants, 32 preterm infants not subjected to antimicrobial therapy, and 1% infants during and after treatment with various antibiotic regimes. There were differences among the untreated infants relating to mode of delivery but not to preterm birth. Caesarean section led to a reduced colonisation by Bifidobacteria and by Bacteroides, and a proneness to colonisation KlebsiellaIEnterobacter. During antibiotic treatment, the anaerobic microflora disappeared in 85% of the cases, also when antibiotics with a narrow spectrum were used. There was a prompt colonisation by Klebsiella/Enterobacter in almost all infants during treatment. After treatment, there was a slow regrowth of Bifidobacterium but no Bacteroides sp. There was a gradual decrease of Klebsiella/Enterobacter colonisation after treatment in most but not all infants. This species tended to persist in larger numbers when there was a concomitant paucity of anaerobic bacteria, especially of Bifidobacterium sp. During 1%9-84, late-onset septiacaemia caused by Klebsiella/Enterobacter or other Gram-negative bacteria except E. cob, occurred only in infants who had been subjected to antibiotic treatment prior to diagnosis. Disturbances of the microbial ecology by Caesarean section or antibiotic treatment may play an etiological role in some cases of neonatal septicaemia. and a few examples will be presented.
Oxygen therapy for intrauterine growth retardation. K.H. Nicolaides, Greenough, King’s College Hospital, Denmark Hill, London, U.K.
R.J.
Bradley
and
A.
Severe intrauterine growth retardation (IUGR) and oligohydramnios in the second trimester of pregnancy indicate a very poor prognosis for the fetus. The present management is to wait in the hope that the fetus reaches the stage of viability and may be delivered prematurely before intrauterine death occurs. In the present study we investigated whether prolonged maternal oxygen administration would benefit the previable hypoxaemic growth retarded fetus. Oxygen therapy (continuous administration of humidified 55% oxygen via an MC mask) was given to 5 patients who fulfilled the following criteria: (1) ultrasound abdominal circumference < 5th centile; (2) oligohydramnios; (3) abnormal fetal blood velocity waveforms as measured by Doppler; (4) fetal PO2 < 5th centile; rise in fetal PO2 with maternal hyperoxygenation. Four of the pregnancies (5 babies) were successfully delivered and the infants are well. One the pregnancies ended in an intrauterine death.
Maturation of peripheral chemoreceptors
in ?orm~l ? newborn infants. R. A. Wilkie, M.H. Bryan, S. Gaston and A.C. Bryan, Research Institute Hospital for Sick Children, Toronto, Ninewells Hospital and Medical School, Dundee.
Blanc0 et al. (J. Physiol., 351 (1984) 25) have shown in lambs that the carotid chemoreceptors do not respond to hypoxia in the first week of life. We studied the carotid chemoreflex in human infants in the fist 6 months of life and showed marked maturational changes. Ventilatory response to a single breath of 1OOOro oxygen was studied in 23 term infants (2-126 days post-natal age). Most infants were studied at least twice at different ages during quiet sleep. Tidal volume (Vt) and frequency were measured with a pneumotachograph. Baseline values for Vr and minute ventilation (Vi) were calculated from the 4 breaths preceding the 100% 02 single breath. Vf and Vi for each of the next 4 breaths were compared to the control breaths and expressed as % change. Four 100% 02 single breath studies were done on each infant and a mean value derived for the maximum response in Vt and Vi. The infants were grouped by age. Using an Anova we found the response of Vt and Vi to a single breath of 100% 02 at 1.7 days to be significantly smaller (P < 0.01) than the response in older infants.
Oxygen therapy for intrauterine growth retardation. K.H. Nicolaides, Greenough, King’s College Hospital, Denmark Hill, London, U.K.
R.J.
Bradley
and
A.
Severe intrauterine growth retardation (IUGR) and oligohydramnios in the second trimester of pregnancy indicate a very poor prognosis for the fetus. The present management is to wait in the hope that the fetus reaches the stage of viability and may be delivered prematurely before intrauterine death occurs. In the present study we investigated whether prolonged maternal oxygen administration would benefit the previable hypoxaemic growth retarded fetus. Oxygen therapy (continuous administration of humidified 55% oxygen via an MC mask) was given to 5 patients who fulfilled the following criteria: (1) ultrasound abdominal circumference < 5th centile; (2) oligohydramnios; (3) abnormal fetal blood velocity waveforms as measured by Doppler; (4) fetal PO2 < 5th centile; rise in fetal PO2 with maternal hyperoxygenation. Four of the pregnancies (5 babies) were successfully delivered and the infants are well. One the pregnancies ended in an intrauterine death.
Maturation of peripheral chemoreceptors
in ?orm~l ? newborn infants. R. A. Wilkie, M.H. Bryan, S. Gaston and A.C. Bryan, Research Institute Hospital for Sick Children, Toronto, Ninewells Hospital and Medical School, Dundee.
Blanc0 et al. (J. Physiol., 351 (1984) 25) have shown in lambs that the carotid chemoreceptors do not respond to hypoxia in the first week of life. We studied the carotid chemoreflex in human infants in the fist 6 months of life and showed marked maturational changes. Ventilatory response to a single breath of 1OOOro oxygen was studied in 23 term infants (2-126 days post-natal age). Most infants were studied at least twice at different ages during quiet sleep. Tidal volume (Vt) and frequency were measured with a pneumotachograph. Baseline values for Vr and minute ventilation (Vi) were calculated from the 4 breaths preceding the 100% 02 single breath. Vf and Vi for each of the next 4 breaths were compared to the control breaths and expressed as % change. Four 100% 02 single breath studies were done on each infant and a mean value derived for the maximum response in Vt and Vi. The infants were grouped by age. Using an Anova we found the response of Vt and Vi to a single breath of 100% 02 at 1.7 days to be significantly smaller (P < 0.01) than the response in older infants.