Total antioxidant capacity and total oxidant status in perinatal asphyxia in relation to neurological outcome

Impact of the Neonatal Resuscitation Program-Recommended Low Oxygen Strategy on Outcomes of Infants Born Preterm

OBJECTIVE

To evaluate the impact of the Neonatal Resuscitation Program (NRP)-recommended low oxygen strategy (LOX) on neonatal morbidities, mortality, and neurodevelopmental outcomes in neonates born preterm.

STUDY DESIGN

In March 2011, Parkland Hospital changed from a high oxygen strategy (HOX) of resuscitation with initial 100% oxygen and targeting 85%-94% oxygen saturation for delivery room resuscitation to a LOX with initial 21% oxygen and titrating oxygen to meet NRP-recommended transitional target saturations. Neonates ≤28 weeks' gestational age born between August 2009 and April 2012 were identified. In this retrospective, observational study, neonates exposed to LOX vs HOX were compared for short-term morbidity, mortality, and long-term neurodevelopmental outcomes. Regression analysis was performed to control for confounding variables.

RESULTS

Of 199 neonates, 110 were resuscitated with HOX and 89 with LOX. Compared with HOX, neonates exposed to LOX had lower oxygen exposure in the delivery room (5.2 ± 1.5 vs 7.8 ± 2.8 [∑FiO2 × time min], P < .01), spent fewer days on oxygen (30 [5, 54] vs 46 [11, 82], P = .01), and had lower odds of developing bronchopulmonary dysplasia (aOR 0.4 [0.2, 0.9]). There was no difference in mortality (17 [20%] vs 20 [18%]), but neonates exposed to LOX had greater motor composite scores on Bayley Scales of Infant and Toddler Development-Third edition assessment (91 [85, 97] vs 88 [76, 94], P < .01).

CONCLUSION

The NRP-recommended LOX strategy was associated with improved respiratory morbidities and neurodevelopmental outcomes with no increase in mortality. Prospective trials to confirm the optimal oxygen strategy for the resuscitation of neonates born preterm are needed.

Status of vitamin D, antioxidant enzymes, and antioxidant substances in neonates with neonatal hypoxic-ischemic encephalopathy

OBJECTIVE

To investigate the concentration of vitamin D (VD), glutathione peroxidase (GP), superoxide dismutase (SOD), malondialdehyde (MDA), and advanced oxidation protein products (AOPP) in neonates with hypoxic-ischemic encephalopathy (HIE).

MATERIAL AND METHODS

This study was performed prospectively in term neonates treated for HIE. Samples were collected from the neonates in study and control groups at 6-14 h and on day 5 of their lives for 25-OH vitamin D3, antioxidant enzymes including GP and SOD and oxidants substances including MDA and AOPP.

RESULTS

This study was performed with 31 term neonates with HIE and 30 healthy term neonates. Maternal VD level was statistically lower in the study group (9.8 ± 6.8 ng/mL) than the control (16.4 ± 8.7 ng/mL) (p = 0.002). SOD and MDA levels were significantly high, and VD level was significantly low in the study group on the first day of life (p = 0.001 and p = 0.028, respectively). SOD and GP levels were significantly high in the study group on day 5 (p < 0.05). VD was significantly low in the study group on day 5 and the proportion of subjects with VD below 5 ng/ml was significantly lower in the control group (p= <0.05).

CONCLUSION

VD has neuroprotective and antioxidant properties. We detected VD levels were low in infants with HIE and their mothers. This finding may be useful for decreasing of brain damage.

Comparison of oxidative stress markers in umbilical cord blood after vaginal and cesarean delivery

Objective

The purpose of our study was to investigate the effect of the mode of delivery on the oxidant and antioxidant system in umbilical cord blood.

Methods

We performed gas analysis of umbilical venous blood and umbilical arterial blood immediately after delivery in 38 women; eighteen women had a vaginal delivery while 20 women delivered via cesarean section at over 37 weeks gestation. We examined lipid peroxide concentration by thiobarbituric acid reaction, protein carbonyl content by 2,4-dinitrophenylhydrazine reaction, and total antioxidant capacity by oxygen radical absorbance capacity assay.

Results

Lipid peroxide levels in umbilical venous blood were significantly higher in patients delivering by planned cesarean section (1.81 ± 0.06 nmol/mg protein) than those with vaginal delivery (1.24 ± 0.05 nmol/mg protein) (P < 0.05). Antioxidant capacity in umbilical venous blood was significantly higher in patients delivering by planned cesarean section (119.70 ± 0.13 µM/µL) than those with a vaginal delivery (118.70 ± 0.29 µM/µL) (P < 0.05). There was no significant difference in the carbonyl content of umbilical venous blood or in the lipid peroxide, carbonyl content, and total antioxidant capacity of umbilical arterial blood.

Conclusion

Lipid peroxidation levels and antioxidant capacity in umbilical venous blood were higher in patients delivering by planned cesarean section than those with a vaginal delivery. Therefore, we propose that both the mother and neonate are exposed to higher oxidative stress during cesarean section delivery.

Prooxidant-antioxidant balance in perinatal asphyxia

OBJECTIVE

To determine the prooxidant-antioxidant balance (PAB) in neonatal asphyxia and compare it with values for PAB in healthy neonates.

METHODS

In a prospective observational study, serum PAB of umbilical cord blood of 30 neonates with asphyxia [pH < 7.2, low Apgar score, signs of respiratory distress syndrome (RDS)] as the case group and 35 healthy neonates (without an abnormal clinical event at birth and after the first week) as the control group were compared.

RESULTS

Among the 35 neonates in the control group, the average level of serum PAB was 20.00 HK units, which was significantly lower than for the 30 neonates within the case group (40.46 HK units; p = 0.019). The blood pH in the case group was significantly lower than for control group (P < 0.001). In controls, HCO3 (-) and pCO2 were 18.6 mmol/L and 38.5 mmHg respectively, whilst in the case group these values were 15.5 mmol/L and 45.7 mmHg respectively (p < 0.05).

CONCLUSIONS

Determination of PAB may be useful in the early diagnosis of perinatal asphyxia and is consistent with HCO3 (-), pCO2 and Apgar score.

Effects of phototherapy using different light sources on oxidant and antioxidant status of neonates with jaundice

BACKGROUND/AIM

Neonates have limited antioxidant protective capacity. It has recently been demonstrated that phototherapy used for treatment of neonatal jaundice produces oxidative stress. Various phototherapy devices using different light sources are available for phototherapy. We aimed to investigate the effects of phototherapy applied with different light sources on the global oxidant/antioxidant status in neonates.

METHODS

Term and late-preterm (≥35 weeks) newborn infants hospitalized to receive phototherapy for non-hemolytic jaundice in the 2-9 days of life were enrolled. Infants who received conventional phototherapy with fluorescent lamps were defined as group 1, intensive light emitting diode (LED) phototherapy as group 2, and fiberoptic phototherapy as group 3. The serum total antioxidant capacity (TAC) and total oxidant status (TOS) were measured before and 24 h after phototherapy. Oxidative stress index (OSI) was calculated.

RESULTS

Twenty nine patients were included in each group. At the beginning of phototherapy serum TAC, TOS and OSI levels were similar in all groups. After phototherapy serum TAC decreased significantly in all three groups (p < 0.001). Total oxidant status increased significantly in group 1 (p < 0.001) and group 2 (p = 0.001) whereas a statistically insignificant increase was observed in group 3 (p = 0.057). After phototherapy OSI increased significantly in group 1 (p < 0.001), group 2 (p = 0.001), and group 3 (p = 0.038).

CONCLUSION

As indicated by increased OSI, oxidant/antioxidant balance is disturbed in favor of oxidants after blue fluorescent light, LED and fiberoptic phototherapy.

Chest compressions for bradycardia or asystole in neonates

When effective ventilation fails to establish a heart rate of greater than 60 bpm, cardiac compressions should be initiated to improve perfusion. The 2-thumb method is the most effective and least fatiguing technique. A ratio of 3 compressions to 1 breath is recommended to provide adequate ventilation, the most common cause of newborn cardiovascular collapse. Interruptions in compressions should be limited to not diminishing the perfusion generated. Oxygen (100%) is recommended during compressions and can be reduced once adequate heart rate and oxygen saturation are achieved. Limited clinical data are available to form newborn cardiac compression recommendations.