Maternal hyperoxygenation in the treatment of intrauterine growth retardation. [Therapy of suspected intrauterine fetal retardation]. [Correlation between the inspired fraction of oxygen, maternal partial oxygen pressure, and fetal partial oxygen pressure during cesarean section of normal pregnancies]. [Is oxygen therapy truly useful and necessary during elective cesarean section under spinal anesthesia?]. Effects of maternal supplementary oxygen on the newborn for elective cesarean deliveries under spinal anesthesia. A double-blind randomised controlled trial of continuous oxygen therapy for compromised fetuses. Low-dose nitric oxide therapy for persistent pulmonary hypertension of the newborn. Clinical Inhaled Nitric Oxide Research Group. Inhaled nitric oxide and persistent pulmonary hypertension of the newborn. The Inhaled Nitric Oxide Study Group. Inhaled nitric oxide reduces the need for extracorporeal membrane oxygenation in infants with persistent pulmonary hypertension of the newborn.
In the current study the efficacy of maternal hyperoxygenation on growth-retarded fetuses was evaluated.
                Thirty-six pregnant women with intrauterine growth retardation were studied. The patients were divided in oxygen-treated (n = 17) and untreated (n = 19) groups. Doppler analysis of the fetal circulation was performed on the arrival to the hospital, after 12 hours, and thereafter on alternate days until delivery. Fetal blood was sampled by cordocentesis for immediate blood gas analysis at entrance to the study and the day of delivery.
                Significant improvement in Doppler flow patterns in treated patients were found when compared with untreated women. The Doppler variations were associated with complementary modifications in fetal blood gas. These differences resulted in a significant modification in perinatal mortality with an incidence of 29% and 68% (p less than 0.01) in treated and untreated groups, respectively.
                Our data suggest a benefit of maternal hyperoxygenation in the treatment of fetal growth retardation. In a randomized prospective study, performed on 45 pregnancies with clinical and sonographic suspicion for intrauterine fetal growth retardation, examinations were done to evaluate the therapeutic effect of bed rest and of additional daily administered glucose infusions or oral galactose applications respectively on the fetal growth, the hemodynamic, respiratory and endocrine insufficiency of the materno-feto-placental unit as well as selected biochemical parameters of the umbilical blood. There is no positive therapeutic effect, either on the impaired endocrine partial function nor on the reduced respiratory function of the feto-placental unit. It is obvious, that despite the improvement of the nutritional supply of the fetus and the revival of the regular fetal growth, the previous lack of fetal growth can not be altered. This can be demonstrated in all three therapeutic groups due to the fact of a resulting high hypotrophy-rate of the newborns. The results prove that the additional supply of the fetus with glucose or galactose does not remarkably improve the therapeutic effectivity as opposed by strict bed rest alone. Despite changes in pulmonary function, maternal oxygenation is maintained during obstetric regional blocks. But in those situations, the administration of supplementary oxygen to parturients is a common practice. Good fetal oxygenation is the main justification; however, this has not been proven. The objective of this randomized, prospective study was to test the hypothesis of whether maternal hyperoxia is correlated with an increase in fetal gasometric parameters in elective cesarean sections.
                Arterial blood gases of 20 parturients undergoing spinal block with different inspired fractions of oxygen were evaluated and correlated with fetal arterial blood gases.
                An increase in maternal inspired fraction of oxygen did not show any correlation with an increase of fetal partial oxygen pressure.
                Induction of maternal hyperoxia by the administration of supplementary oxygen did not increase fetal partial oxygen pressure. Fetal gasometric parameters did not change even when maternal parameters changed, induced by hyperoxia, during cesarean section under spinal block. To analyze maternal and fetal well-being with and without the application of oxygen therapy.
                Randomized trial of full-term parturients who had received prenatal care during pregnancy. The women were healthy and classified as ASA 1. They were scheduled for delivery by cesarean section under spinal anesthesia and randomized to 2 groups to breathe room air or air providing an inspired oxygen fraction of 40% through a face mask. We assessed the well-being of the neonate immediately after birth with the Apgar test and by measuring umbilical cord blood gases.
                One hundred thirty women were enrolled. Both groups were similar, with no differences in demographic or hemodynamic variables, time from uterine incision to fetal extraction, neonatal birth weight, presence of umbilical cord abnormalities, type of resuscitation required by the neonate, or Apgar score in the first or fifth minute. Oxygen saturation in maternal blood by pulse oximetry was higher after 10 minutes in the group of women who received supplemental oxygen through face masks. We also observed significant differences in umbilical cord arterial blood between the room air and supplemental oxygen groups, respectively, as follows: PaCO2, 51.14 mm Hg vs 54.33 mm Hg (P=.016); bicarbonate, 22.19 mEq L(-1) vs 23.23 mEq L(-1) (P=.012); lactate, 1.85 mmol L(-1) vs 1.64 mmol L(-1) (P=.038). The PO2 in venous blood also differed significantly: 25.53 mm Hg vs 28.13 mm Hg, respectively (P=033).
                Breathing supplemental oxygen or not during elective cesarean delivery of healthy parturients under spinal anesthesia does not have a significant effect on neonatal well-being. The aim of this investigation was to determine whether supplementary oxygen provided by either nasal cannula or face mask versus room air might affect fetal oxygenation during elective cesarean section under spinal anesthesia by assessing maternal and neonatal regional cerebral oxygenation (rSO(2)) with a cerebral oximeter.
                Ninety parturients were randomly allocated into three groups: two groups received 5 L/min oxygen by either nasal cannula (Group NC, n = 30) or face mask (Group FM, n = 30), respectively, and the third group was allowed to breathe room air (Group RA, n = 30). After maternal mean arterial pressure, heart rate and peripheral oxygen saturation had been monitored, rSO(2) was determined by cerebral oximeter. Umbilical artery (UA) and venous (UV) blood samples were collected for blood gas analysis. Neonatal rSO(2) and Apgar scores were recorded.
                The mean maternal rSO(2) which was recorded 3 and 5 min after administration of the spinal block in Group FM was lower than that of Group NC (p = 0.033 and 0.042, respectively). Neonatal rSO(2), UA pH, UV pH and UA base excess (BE) were lower in Group FM than in the other groups (p < 0.05). The Apgar score (1 min) in Group FM was lower than that of Group RA (p = 0.046).
                The effect of maternal supplementary oxygen on the newborn has been demonstrated by a cerebral oximeter monitor and supported by umbilical cord blood gas analysis and Apgar scores. To investigate the effect of chronic oxygen therapy in fetuses with absent end diastolic flow in the umbilical artery assessed by doppler analysis at 24-30 weeks of gestation.
                A double-blind, randomised control trial was performed with patients blindly allocated to receive humidified oxygen or humidified air.
                A tertiary referral hospital in South Africa.
                Thirty-two women who presented between 24 and 30 weeks of gestation with a confirmed finding of absent end diastolic flow in the umbilical artery.
                After randomisation patients were allocated to receive a 40% mixture of humidified oxygen or humidified air from uniform coloured gas cylinders which were marked either 'a' or 'b' All women received betamethasone from 27 weeks of gestation on a weekly basis. Cardiotocographs were used from 28 weeks of gestation; after 28 weeks of gestation an amniocentesis was considered to confirm fetal maturity. Women were expected to breath the allocated gas continuously apart from meals and visits to the toilet.
                Survival of the fetus was the main outcome measure with secondary outcome measures documenting improvement in the fetal condition in utero.
                There were 16 women randomised to receive oxygen and 16 to receive air. There were nine survivors in the oxygen group (56.3%) and six in the air group (37.5%) (relative risk 1.5, 95% confidence interval 0.7-3.2). There was a nonsignificant increase in mean birthweight in the oxygen group (858.3 grammes vs 774.4 grammes) and a nonsignificant increase in mean duration of treatment in the oxygen group (12.8 days vs 10.4 days).
                This study did not demonstrate that chronic oxygen therapy provides any benefits to compromised fetuses between 24 and 30 weeks of gestation. Larger studies with sufficient power are necessary to assess whether oxygen therapy can reduce perinatal mortality by a clinically useful amount in this group of patients. Inhaled nitric oxide improves gas exchange in neonates, but the efficacy of low-dose inhaled nitric oxide in reducing the need for extracorporeal membrane oxygenation has not been established.
                We conducted a clinical trial to determine whether low-dose inhaled nitric oxide would reduce the use of extracorporeal membrane oxygenation in neonates with pulmonary hypertension who were born after 34 weeks' gestation, were 4 days old or younger, required assisted ventilation, and had hypoxemic respiratory failure as defined by an oxygenation index of 25 or higher. The neonates who received nitric oxide were treated with 20 ppm for a maximum of 24 hours, followed by 5 ppm for no more than 96 hours. The primary end point of the study was the use of extracorporeal membrane oxygenation.
                Of 248 neonates enrolled, 126 were randomly assigned to the nitric oxide group and 122 to the control group. Extracorporeal membrane oxygenation was used in 78 neonates in the control group (64 percent) and in 48 neonates in the nitric oxide group (38 percent) (P=0.001). The 30-day mortality rate in the two groups was similar (8 percent in the control group and 7 percent in the nitric oxide group). Chronic lung disease developed less often in neonates treated with nitric oxide than in those in the control group (7 percent vs. 20 percent, P=0.02). The efficacy of nitric oxide was independent of the base-line oxygenation index and the primary pulmonary diagnosis.
                Inhaled nitric oxide reduces the extent to which extracorporeal membrane oxygenation is needed in neonates with hypoxemic respiratory failure and pulmonary hypertension. Persistent pulmonary hypertension of the newborn causes systemic arterial hypoxemia because of increased pulmonary vascular resistance and right-to-left shunting of deoxygenated blood. Inhaled nitric oxide decreases pulmonary vascular resistance in newborns. We studied whether inhaled nitric oxide decreases severe hypoxemia in infants with persistent pulmonary hypertension.
                In a prospective, multicenter study, 58 full-term infants with severe hypoxemia and persistent pulmonary hypertension were randomly assigned to breathe either a control gas (nitrogen) or nitric oxide (80 parts per million), mixed with oxygen from a ventilator. If oxygenation increased after 20 minutes and systemic blood pressure did not decrease, the treatment was considered successful and was continued at lower concentrations. Otherwise, it was discontinued and alternative therapies, including extracorporeal membrane oxygenation, were used.
                Inhaled nitric oxide successfully doubled systemic oxygenation in 16 of 30 infants (53 percent), whereas conventional therapy without inhaled nitric oxide increased oxygenation in only 2 of 28 infants (7 percent). Long-term therapy with inhaled nitric oxide sustained systemic oxygenation in 75 percent of the infants who had initial improvement. Extracorporeal membrane oxygenation was required in 71 percent of the control group and 40 percent of the nitric oxide group (P=0.02). The number of deaths was similar in the two groups. Inhaled nitric oxide did not cause systemic hypotension or increase methemoglobin levels.
                Inhaled nitric oxide improves systemic oxygenation in infants with persistent pulmonary hypertension and may reduce the need for more invasive treatments. We previously reported improved oxygenation, but no change, in rates of extracorporeal membrane oxygenation (ECMO) use or death among infants with persistent pulmonary hypertension of the newborn who received inhaled nitric oxide (NO) with conventional ventilation, irrespective of lung disease. The goal of our study was to determine whether treatment with inhaled NO improves oxygenation and clinical outcomes in infants with persistent pulmonary hypertension of the newborn and associated lung disease who are ventilated with high-frequency oscillatory ventilation (HFOV).
                Single-center, prospective, randomized, controlled trial.
                Newborn intensive care unit of a tertiary care teaching hospital.
                We studied infants with a gestational age of > or =34 wks who were receiving mechanical ventilatory support and had echocardiographic and clinical evidence of pulmonary hypertension and hypoxemia (PaO2 < or =100 mm Hg on FIO2 = 1.0), despite optimal medical management Infants with congenital heart disease, diaphragmatic hernia, or other major anomalies were excluded.
                The treatment group received inhaled NO, whereas the control group did not. Adjunct therapies and ECMO criteria were the same in the two groups of patients. Investigators and clinicians were not masked as to treatment assignment, and no crossover of patients was permitted.
                Primary outcome variables were mortality and use of ECMO. Secondary outcomes included change in oxygenation and duration of mechanical ventilatory support and supplemental oxygen therapy. Forty-two patients were enrolled. Baseline oxygenation and clinical characteristics were similar in the two groups of patients. Infants in the inhaled NO group (n = 21) had improved measures of oxygenation at 15 mins and 1 hr after enrollment compared with infants in the control group (n = 20). Fewer infants in the inhaled NO group compared with the control group were treated with ECMO (14% vs. 55%, respectively; p = .007). Mortality did not differ with treatment assignment.
                Among infants ventilated by HFOV, those receiving inhaled NO had a reduced need for ECMO. We speculate that HFOV enhances the effectiveness of inhaled NO treatment in infants with persistent pulmonary hypertension of the newborn and associated lung disease.
There is not enough evidence to evaluate the benefits and risks of maternal oxygen therapy for suspected impaired fetal growth. Further trials of maternal hyperoxygenation seem warranted.