Risk factors for hypoxic-ischemic encephalopathy in asphyxiated newborn infants.

OBJECTIVE: To determine the risk factors for hypoxic-ischemic encephalopathy (HIE) in asphyxiated newborn infants. MATERIAL AND METHOD: A retrospective study of 17,706 newborns, who were admitted to the Neonatal Unit of King Chulalongkorn Memorial Hospital, from July 1999 till the end of December 2000. 84 infants with perinatal asphyxia were enrolled in the present study. All of the possible risk factors that might have contributed to asphyxia were identified and recorded HIE was diagnosed based on the Modified Sarnat-Sarnat Score for the diagnosis of neonatal encephalopathy. The clinical data of the HIE group were compared with those of the HIE negative group. The categorical data were analyzed for statistical significance (p < 0.05) by Chi-square test or Fisher exact test, or Student t-test. The odds ratio and 95% CI were calculated for those with statistical significance. Stepwise multiple logistic regression analysis used to determine the independent factors that may predispose an infant to HIE. RESULTS: Inappropriate antenatal care (OR 9.4; 95%CI: 2.6-35.4), post-term gestation (OR 7.4; 95%CI: 1.4-34.8), vacuum extraction (OR 5.4; 95%CI: 1.1-26.8), male (OR 4.8; 95%CI: 1.3-19.1), prolapsed cord (p = 0.01) and 1 and 5-minute Apgar scores, (p < 0.0001) were significant risk factors for HIE. However, by multiple regression analysis, only a 5-minute Apgar score was significantly associated with HIE (p = 0.001). CONCLUSION: Sophisticated or expensive equipment is not necessary for the treatment of HIE patient. HIE depends mainly on adequate and effective supportive strategy. The delivery of high risk pregnancies, under obstetric facilities and with appropriate intervention and with good neonatal resuscitation, may prevent the perinatal asphyxia and thereby minimize the occurring of HIE.

Transepidermal water loss during conventional phototherapy in nonhemolytic hyperbilirubinemia term infants.

The evaporation rate from the skin was measured in 40 healthy term infants and 40 non-hemolytic jaundice term infants who required phototherapy. All infants were born at the gestational age of 38-41 weeks. The method for measurement of evaporation rate was based on determination of the water pressure gradient close to the skin surface. Conventional phototherapy was given in open cribs. In the phototherapy group, non of the infants had received phototherapy before the start of measurement. Evaporation rate was measured at the chest, interscapular and buttock. The measurement was made before phototherapy, 30 minutes, and 6 hours after starting phototherapy. The mean evaporation rate increased from 7.2 to 7.8 and 8.4 g/m2 h, respectively (p<0.001). In the control group, the measurement was made at the consecutive time as in the phototherapy group. The mean of the evaporate rate was 7.3, 7.6 and 7.5 g/m2 h (p=0.30). We conclude that conventional phototherapy in full term infants in open cribs increases transepidermal water loss.

Effects of clear topical ointment on transepidermal water loss in jaundiced pretermm infants receiving phototherapy.

Thirty jaundiced preterm infants, gestational age < or = 34 weeks and postnatal age < or = 7 days, receiving conventional phototherapy for hyperbilirubinemia of prematurity in incubators were included. 1.5 ml of clear topical ointment was applied on the right side of the trunk and extremities while the left side was used as control. Data collection included transepidermal water loss (TEWL), ambient temperature and ambient humidity, before and at 30 minutes, 4-6 hours after application of the ointment during phototherapy. The measurements were executed both the right and left side in 3 positions; upper arm, back, lower leg. TEWL was reduced by 29 per cent (P value < 0.002) and 26 per cent (P value < 0.011) at 30 minutes and 4-6 hours after the application of clear topical ointment, respectively. Ambient temperature and humidity were not significantly different (P value > 0.18). We concluded that application of clear topical ointment on the skin of jaundiced preterm infants receiving conventional phototherapy in incubators reduced TEWL significantly.

Immune responses to measles immunization and the impacts on HIV-infected children.

This prospective cohort study was conducted to determine the seroconversion rate and the pattern of antibody response to measles vaccine administered at age 9 months in HIV infected and non-infected children born to HIV-1 seropositive mothers. Thirty children born to HIV-1 seropositive mothers and 3 born to HIV-1 seronegative mothers were recruited. One single dose of Schwarz strain of measles virus vaccine (Rouvax) was given to every child at 9 months of age. Clinical status and measles antibody levels were evaluated at the time just before vaccination, 2 and 12 weeks post-vaccination. Antibody was measured by an enzyme immunoassay commercial kit (Enzygnost, Dade Behring Manufacturer, Germany). Children were classified into 3 groups, groups 1 and 2 were children with and without HIV infection respectively. Group 3 children were those born to HIV-1 seronegative mothers. Of the 33 enrolled children, 16, 14 and 3 were classified as groups 1, 2 and 3 respectively. Four children, 2 of each, in groups 1 and 3 did not complete the study. Group 3 was excluded due to the small number of children recruited. There was no short term complication and no measles infection noted during the course of study. None of the children had pre-existing antibodies. The median (range) of CD4 count and CD4/CD8 ratio measured at the time of vaccination were statistically different between groups 1 and 2 children. Group 2 children had better antibody response than group 1 in terms of seroconversion rate and median of antibody levels at 12 weeks post-vaccination. Only 7 of 29 children (24.1%) had detectable measles antibodies at 2 weeks post-vaccination. A decrease in antibody was noted in 2 symptomatic HIV infected children as their disease had progressed. Various potential predictors of measles vaccine responses in HIV infected children including CD4 count and CD4/CD8 ratio were not statistically different between the responders and non-responders. All 4 asymptomatic HIV infected children were responders. This study demonstrated that all of the children had already lost their maternal acquired antibodies at age 9 months. HIV infected children had a poorerantibody response to measles vaccine than the non-infected children.

Safety and immunogenicity of Bacillus Calmette-Guerin vaccine in children born to HIV-1 infected women.

This prospective cohort study was conducted to determine the complication of Bacillus Calmette-Guerin (BCG) vaccination given to newborn infants born to HIV-1 seropositive mothers and to compare the tuberculin reaction 9 months after BCG vaccination between HIV-1 infected and non infected children. Two hundred and twenty-three infants with BCG immunization at birth were examined. No BCG complication was noted. Tuberculin skin tests were performed on 126 children (56.5%). Eleven of them were excluded because of failure to have skin tests read at 48 hours. Of the 115 infants enrolled to this study, 15 (13%) had no BCG scar and 50 (43.5%) had no tuberculin reaction. Twenty-six children were classified as group 1 or HIV-1 infected children and 89 children were group 2 or HIV-1 non infected. Group 1 children had a smaller tuberculin skin response (X+SD) than group 2 (1.15 +/- 2.82 vs 4.64 +/- 4.29 mm; p < 0.0001). Mean weight + SD of group 1 children was also significantly less than those in group 2 (8,013 +/- 741 vs 8,540 +/- 984 g; p < 0.05). The proportion of children with non reactivity to the tuberculin test, a negative tuberculin test and no BCG scar in group 1 was significantly higher than that in group 2 (76.9% vs 33.7%, 92.3% vs 52.8% and 36.4% vs 6.7% respectively; p < 0.0001 for all). But, the proportion of non reactivity to the tuberculin test in children with or without BCG scar of each group was not different (p > 0.05). Positive tuberculin tests were 7.7% and 47.2% in group 1 and 2 respectively. None of the children with positive tuberculin tests had clinical evidence of tuberculosis. The findings of this study indicate that BCG vaccine given to newborn infants of HIV-1 seropositive mothers is safe. Although tuberculin skin responses of HIV-1 infected children are less than those of HIV-1 non-infected children, it is possible that BCG vaccine might protect these children from developing severe tuberculosis.