Predictors of Clinical Outcome in the Newborns of Persistent Pulmonary Hypertension Treated with Inhaled Nitric Oxide

PURPOSE: Inhaled nitric oxide (iNO) has been known to improve oxygenation in newborns with persistent pulmonary hypertension (PPHN). This study was performed to evaluate the predictors of clinical outcome in the newborn infants with PPHN treated with iNO. METHODS: Between September 1998 and August 2002, 23 newborn infants with PPHN treated with iNO were enrolled in this study. Reduction of oxygenation index (OI) and AaDO2 to 30% or more were defined as clinical response. Accoding to the response time within or after 12 hours, the clinical response was sub-categorized as early or delayed response, respectively. RESULTS: The mean gestational age and birth weight of 23 newborn infants were 36.7+/-4.4 weeks and 2,644+/-907 g. The mean baseline OI and AaDO2 were 22.20+/-13.63 and 477.16+/-127.96. There were ten non-responsders, eight early responsders and five delayed responders. Eleven neonates showed sustained response for 24 hours. The mean AaDO2, and PaO2 were decreased after 12 hours (P<0.05), while there was no difference in oxygenation index, arteral pH and PaCO2. The mortality rates of non-responders or not- sustained responders were higher than those of responders or sustained responders (P< 0.05). The birth weight of death group was lower than that of survival group and AaDO2, and OI at 12 hours after iNO therapy in survival group were lower than those in death group. CONCLUSION: Predictors of the clinical outcome of iNO therapy were clinical response patterns after iNO therapy, time taken until clinical response, duration of response and change of oxygenation at 12 hours after iNO therapy.

Predictors of Clinical Outcome in the Newborns of Persistent Pulmonary Hypertension Treated with Inhaled Nitric Oxide

PURPOSE: Inhaled nitric oxide (iNO) has been known to improve oxygenation in newborns with persistent pulmonary hypertension (PPHN). This study was performed to evaluate the predictors of clinical outcome in the newborn infants with PPHN treated with iNO. METHODS: Between September 1998 and August 2002, 23 newborn infants with PPHN treated with iNO were enrolled in this study. Reduction of oxygenation index (OI) and AaDO2 to 30% or more were defined as clinical response. Accoding to the response time within or after 12 hours, the clinical response was sub-categorized as early or delayed response, respectively. RESULTS: The mean gestational age and birth weight of 23 newborn infants were 36.7+/-4.4 weeks and 2,644+/-907 g. The mean baseline OI and AaDO2 were 22.20+/-13.63 and 477.16+/-127.96. There were ten non-responsders, eight early responsders and five delayed responders. Eleven neonates showed sustained response for 24 hours. The mean AaDO2, and PaO2 were decreased after 12 hours (P<0.05), while there was no difference in oxygenation index, arteral pH and PaCO2. The mortality rates of non-responders or not- sustained responders were higher than those of responders or sustained responders (P< 0.05). The birth weight of death group was lower than that of survival group and AaDO2, and OI at 12 hours after iNO therapy in survival group were lower than those in death group. CONCLUSION: Predictors of the clinical outcome of iNO therapy were clinical response patterns after iNO therapy, time taken until clinical response, duration of response and change of oxygenation at 12 hours after iNO therapy.

The Usefulness of the CRIB ( Clinical Risk Index for Babies ) Score as a Prognostic Indicator in the Very Low Birth weight Infants

PURPOSE: This study was aimed to assess the ability of CRIB score as a prognostic indicator in the very low birth weight infants (VLBWI) compared with gestational age and birth weight. METHODS: The medical records of 85 newborns <1,500 g of birth weight were reviewed retrospectively. CRIB score was calculated from six factors (birth weight, gestational age, the presence of congenital malformation, maximum base excess, minimum and maximum appropriate inspired oxygen concentration in the first 12 hours). Neurological rnorbidities such as intraventricular hemorrhage (IVH), increased periventricular echogenicity (PVE), periventricular leukomalacia (PVL) were evaluated. RESULTS: The mean birth weight was 1,152229 g, average gestational age 293.8 weeks, average CRIB scores 5.3+/-4.14 (range 0-16). Mortality rate was 32% (27/85). Neurological morbidities were detected as IVH over grade II in 35 (41%), as increased PVE in 34 (40%) and as PVL in 9 (11%). CRIB score showed significant positive relation with themortality (P<0.05), but not with IVH, PVE, and PVL. CRIB score was a little better for the prediction of mortality than birth weight and gestational age without statistical significance (ROC of 0.784 with CRIB score, 0.708 with birth weight, 0.762 with gestational age). CRIB score was as good for the prediction of neurological morbidity as birth weight and gestational age. CONCLUSION: This study revealed that CRIB score is a useful method to predict the mortality of VLBWI. It is necessary to reevaluate the usefulness of CRIB score with a larger number of VLBWI in the future.

Is Pneumocystis carinii vertically transmitted to neonatal rats?

Pneumocystis carinii is a pulmonary pathogen of immunocompromised humans or other mammals. Its infection results from activation of organisms involved in latent infection or from new infection through the air. Almost all children are known to be infected within 2 to 4 years of birth, though prenatal transplacental transmission has not yet been demonstrated. In this study we observed experimental P. carinii infection in neonatal rats, thus investigating the possibility of transplacental vertical transmission by Diff-Quik staining of the lung impression smears and in-situ hybridization for lung sections. The positive rate of P. carinii infection in immunosuppressed maternal rats was 100%, but that in normal maternal rats was 0%. Cystic forms of P. carinii were observed in three of six 1-week old neonatal rats born of heavily infected mothers, but none of them was positive by in-situ hybridization. Five weeks after birth, cystic forms were detected in four neonatal rats. In the lobes of the lungs, no predilection site of P. carinii was recognized. Counts of cystic forms on smears and the reactivity of in-situ hybridization in the lungs of neonatal rats were significantly lower than in maternal rats. The present findings suggest that P. carinii is rarely transmitted through the placenta and proliferates less successfully in the lungs of neonatal rats than in mothers.

Toxoplasma gondii antibody titers in sera of children admitted to the Seoul National University Children's Hospital

A total of 542 children under 10 years of age, admitted to the Seoul National University Children's Hospital, was examined for antibody titers of Toxoplasma gondii using indirect latex agglutination (ILA) test. Among them, 7.7% showed positive titers higher than 1:32, without significant difference between males (7.3%) and females (8.5%). The seropositive rate increased with age although the statistical significance was negligible (0.05 < P < 0.1). By residential areas, the prevalence appeared higher among children from southern provinces (Kyongsang-do and Cholla do) than those from other areas, but the statistical significance was also very low (0.05 < P < 0.1). When the seropositive cases were analyzed by coincidental diseases, the prevalence was significantly higher in patients with congenital diseases than in patients with non-congenital diseases (P < 0.05). The results showed that the seropositive rate of toxoplasmosis in children examined was not high compared with other endemic countries. Some correlations are suggested between toxoplasmosis and congenital anomalies in Korea.

Re-Evaluation of Neonatal Screening Tests for Inborn Errors of Metabolism with Dried Filter Paper Blood Spots

PURPOSE: There have been high rates of false positive and recall in neonatal screening test using the cut-off points set by the manufacturing company. So, it is necessary to re-evaluate the cut-off values to minimize the false positive rates. METHODS: We collected capillary blood in dry filter paper from 996 healthy neonates on the third day in cases of normal vaginal delivery or the fifth day in cases of Cesarean section. The levels of phenylalanine, galactose, 17-hydroxyprogesterone and branched-chain amino acids were measured using enzyme immunoassay. The results were compared with the original cut-off points set by the manufacturing company. RESULTS: The original cut-off points of four substances were 4.0mg/dL, 7.5mg/dL, 35ng/mL, and 8.0mg/dL, respectively, so that false-positive rates were 0.4, 1.6, 3.93, and 0.001%, respectively. When we set the cut-off point at 99.7 percentile using the data from healthy neonates, they should be 4.0mg/dL, 9.2mg/dL, 54.3ng/mL, and 8.0mg/dL, respectively. CONCLUSION: The false-positive and recall rates were higher in galactosemia and congenital adrenal hyperplasia when using the original cut-off points, suggesting that it would be reasonable to modify the cut-off point at 99.7 percentile after measuring those substances from enough of healthy neonates.

Re-Evaluation of Neonatal Screening Tests for Inborn Errors of Metabolism with Dried Filter Paper Blood Spots

PURPOSE: There have been high rates of false positive and recall in neonatal screening test using the cut-off points set by the manufacturing company. So, it is necessary to re-evaluate the cut-off values to minimize the false positive rates. METHODS: We collected capillary blood in dry filter paper from 996 healthy neonates on the third day in cases of normal vaginal delivery or the fifth day in cases of Cesarean section. The levels of phenylalanine, galactose, 17-hydroxyprogesterone and branched-chain amino acids were measured using enzyme immunoassay. The results were compared with the original cut-off points set by the manufacturing company. RESULTS: The original cut-off points of four substances were 4.0mg/dL, 7.5mg/dL, 35ng/mL, and 8.0mg/dL, respectively, so that false-positive rates were 0.4, 1.6, 3.93, and 0.001%, respectively. When we set the cut-off point at 99.7 percentile using the data from healthy neonates, they should be 4.0mg/dL, 9.2mg/dL, 54.3ng/mL, and 8.0mg/dL, respectively. CONCLUSION: The false-positive and recall rates were higher in galactosemia and congenital adrenal hyperplasia when using the original cut-off points, suggesting that it would be reasonable to modify the cut-off point at 99.7 percentile after measuring those substances from enough of healthy neonates.

The Efficacy of Fetal Ultrasonography and Postnatal Abdominal Ultrasonography for the Diagnosis of Neonatal Abdominal Mass

PURPOSE: Most neonatal abdominal masses are benign in nature, but early detection and management is important to avoid the development of complications. So, we studied the causes of neonatal abdominal masses and the efficacy of ultrasonography for early detection and diagnosis. METHODS: We reviewed 36 newborn infants with abdominal masses who had been admitted to the nursery and Neonatal Intensive Cave Unit of Seoul National University Children' s Hospital from Jan. 1, 1989 to Dec. 31, 1995. RESULTS: The mean gestational age was 38 weeks and the male to female ratio was 22 : 14. All masses were benign and the most common etiology was hydronephrosis (41.7%). The following etiologies were multicystic dysplastic kidney, polycystic kidney, ovarian cyst, hemangioendothelioma, teratoma, meconium peritonitis, mesenteric cyst and intestinal duplication cyst. All except one were detected before the first 48hours, and among them, 32 cases (88.9%) detected antenatally. All patients except one who died shortly after birth, were examined by abdominal ultrasonography, and 31 of 35 masses (88.6%) had the same diagnosis of ultrasonography. Five cases had associated abnormalities in the opposite kidney and other organs. CONCLUSION: The most common etiology of neonatal abdominal masses was hydronephrosis and majority of masses originated from genitourinary system. Most abdominal masses were detected antenatally and abdominal ultrasonography was an efficient method for the diagnosis of neonatal abdominal masses.

Perinatal Factors Influencing Clinical Response to Surfactant Replacement Therapy in Neonates with Respiratory Distress Syndrome

PURPOSE: Surfactant replacement therapy significantly decreases neonatal complications and mortality in neonates with respiratory distress syndrome (RDS), but clinical responses to the treatment is not consistent. An analysis of the perinatal factors influencing the clinical response to the therapy is important for early detection of high risk and prognosis. The purpose of this study is to analyze the clinical responses to the therapy and to assess the perinatal factors influencing the clinical response. METHODS: From April 1992 to Dec. 1995, 80 infants were enrolled in this study. Medical records were reviewed, and the clinical response to the therapy was defined by a change in the ventilatory index (VI). The perinatal factors were compared according to the clinical response. RESULTS: "Good" response was found in 58 infants (72.5%), "poor" in 14 infants (17.5%), and eight infants (10%) had a "relapse". The factor affecting the response to the therapy in the comparison among the three groups was pretreatment VI, reflecting the severity of the underlying disease. In the comparison between the initial response group and initial non-responders, pretreatment FiO2, pretreatment arterial pH, a/APO2, and VI were significantly different. With control of compounding variables, only pretreatment VI was a significant independent risk factor of the "poor" response. CONCLUSION: The clinical response to surfactant replacement therapy is only influenced by the severity of RDS. According to the results, we speculate that the dosage of surfactant in high pretreatment VI is needed to be increased, and further studies are required to determine the adequate dosage of surfactant in high risk infants.

Comparison of Continuous Versus Intermittent Infusion of Indomethacin in PDA of Preterm Infants

PURPOSE: Patent ductus arteriosus (PDA) of prematurity is very important disease to study because it causes many cases of perinatal morbidity and its incidence is now increasing. Nowadays indomethacin is the drug of choice for PDA closure, but its use has been limited due to its side effects. Therefore, we compared the effect and side effects of indomethacin according to the infusion method, continuous versus intermittent infusion, to find better an administration method. METHODS: Twenty-five preterm infants who were admitted to Seoul National University Children's Hospital (SNUCH) NICU from March 1995 to August 1996 with a diagnosis of respiratory distress syndrome (RDS) and PDA, were enrolled. They were randomly assigned to intertmittent lV group or continuous lV group. Each group received three intermittent doses or continuous infusion over 36 hours, respectively. We analyzed the perinatal history, time of diagnosis and treatment of PDA, size of PDA, and compared the laboratory parameters, intraventricular hemorrhage (IVH), periventricular echogenecity (PVE), ductal closure and perinatal morbidity before and 48 hours after indomethacin administration between the two groups. RESULTS: Fourteen infants (birth weight 1,149 +/- 373g) were intermittent lV group and eleven infants (birth weight 1,212 +/- 504g) were continuous lV group. There were no significant difference between the groups in perinatal history, pretreatment laboratory parameters, ductal closure, and perinatal morbidity. Patients with IVH of grade 2 or more increased significantly in intermittent lV group (50%) compared to continuous lV group (9%), and PVE progressed significantly in intermittent lV group (64%) compared to continuous lV group (18%). CONCLUSION: Continuous infusion of indomethacin for PDA closure in preterm infants with RDS appears to be as effective as intermittent infusion of indomethacin in closing PDA and have less side effects such as IVH and PVE progress.

Statistical Study of Extremely Low Birth Weight (ELBW) Infants / 대한주산의학회잡지

PURPOSE: The purpose of our study was to review the perinatal clinical characteristics of extremely low birth weight(ELBW) infants and determine their risk factors of their deaths. METHODS: The medical records of 96 infants weighing less than 1,000g, who were born at Seoul National University Hospital and admitted to our neonatal intensive care unit(NICU) were analyzed retrospectively on the basis of clinical characteristics, obstetrical problems, postnatal complications and outcome. RESULTS: The annual birth rate of ELBW infants was 0.11% to 0.90% of total live births and the mean annual birth rate was 0.56% at Seoul National University Hospital. Preeclampsia was the most common obstetrical problem(34.4%), followed by incompetent internal os of cervix(IIOC) (13.5%), multiple pregnancy(13.5%) and in vitro fertilization(IVF)(13.5%). Respiratory distress syndrome(RDS) was the most common postnatal complication(78.1%), followed by sepsis(60.4%) and apnea(39.6%). Comparing the ELBW infants weighing less than 750g with those weighing more than 751g, sepsis was more frequent in the latter group(p<0.05), whereas high grade intraventricular hemorrhage(grade Ill) was more frequent in the former group(p<0.05). Otherwise there was no statistically significant difference concerning the frequency of perinatal complications between two groups. Comparing the ELBW infants born before the year 1991, when surfactant treatment started to be used routinely at our NICU, with those born after the year 1991, apnea and sepsis could be observed more frequent in the latter group(p<0.05). Otherwise there was no statistically significant difference in the frequency of perinatal complications between two groups, The survival rate of ELBW infants was 0.0% in 1986, 50.0% in 1991 and 40.0% in 1995. The risk factors of neonatal deaths of ELBW infants included birth weight, gestational period, mode of delivery, IIOC, RDS, apnea, pneumonia, pneumothorax, acute renal failure(ARF) and infections(except pneumonia), but analyzing these risk factors by multivariate logistic regression analysis, the resultant significant independent risk factors consisted only of birth weight, RDS and pneumonia(p<0.05). There was no statistically significant difference in survival rate between ELBW infants born before and after the year 1991, but there was a tendency toward increasing survival rates in the latter group. CONCLUSION: Recently, the survival rate of ELBW infants is improving steadily, but is still lower than that of western countries and postnatal morbidity remains high. Therefore, there is an urgent need to give more efforts to the neonatal intensive care of ELBW inFants in order to increase survival rates and reduce postnatal morbidity. But it is more important to reduce preterm birth by the treatment of preventable obstetrical risk factors.

Comparison of Continuous versus Intermittent Infusion of Indomethacin in PDA of Preterm Infants

PURPOSE: Patent ductus arteriosus (PDA) of prematurity is very important disease to study because it causes many cases of perinatal morbidity and its incidence is now increasing. Nowadays indomethacin is the drug of choice for PDA closure, but its use has been limited due to its side effects. Therefore, we compared the effect and side effects of indomethacin according to the infusion method, continuous versus intermittent infusion, to find better an administration method. METHODS: Twenty-five preterm infants who were admitted to Seoul National University Children's Hospital (SNUCH) NICU from March 1995 to August 1996 with a diagnosis of respiratory distress syndrome (RDS) and PDA, were enrolled. They were randomly assigned to intertmittent lV group or continuous lV group. Each group received three intermittent doses or continuous infusion over 36 hours, respectively. We analyzed the perinatal history, time of diagnosis and treatment of PDA, size of PDA, and compared the laboratory parameters, intraventricular hemorrhage (IVH), periventricular echogenecity (PVE), ductal closure and perinatal morbidity before and 48 hours after indomethacin administration between the two groups. RESULTS: Fourteen infants (birth weight 1,149 +/- 373g) were intermittent lV group and eleven infants (birth weight 1,212 +/- 504g) were continuous lV group. There were no significant difference between the groups in perinatal history, pretreatment laboratory parameters, ductal closure, and perinatal morbidity. Patients with IVH of grade 2 or more increased significantly in intermittent lV group (50%) compared to continuous lV group (9%), and PVE progressed significantly in intermittent lV group (64%) compared to continuous lV group (18%). CONCLUSION: Continuous infusion of indomethacin for PDA closure in preterm infants with RDS appears to be as effective as intermittent infusion of indomethacin in closing PDA and have less side effects such as IVH and PVE progress.

Association of Early Postnatal Neutropenia and Development of Bronchopulmonary Dysplasia in Preterm Infants

PURPOSE: To see if a similar relationship exists between the decreased number of circulating neutrophils and the development of bronchopulmonary dysplasia (BPD) in preterm infants, we tried to test the hypothesis that claims that preterm infants, who develop BPD, have decreased number of circulating neutrophils than those who do not develop BPD. METHODS: A retrospective cohort study was conducted in 167 preterm infants from August 1995 to July 1997, who were admitted in the neonatal intensive care unit (NICU) of Seoul National University Children's Hospital. RESULTS: BPD was diagnosed in 16% (27/167) of preterm infants. We compared the clinical characteristics of the study population according to the presence or absence of BPD. Compared to non-BPD group, the BPD group had a lower gestational age (29.4 +/- 2.7weeks versus 32.7 +/- 1.7 weeks), lower birth weight (1,240 +/- 486g versus 1,780 +/- 420g), lower incidence of prenatal steroid use (2/27 versus 41/140), decreased number of circulating neutrophils (3,622 +/- 4,866/microliter versus 7,586 +/- 4,545/microliter) at 1 day of life. After adjusting for the variables of the above risk factors, neutropenia (<2,500/microliter) in the peripheral blood increased the odds ratio of developing BPD (OR : 46.3, 95% CI : 17.3-117.2). CONCLUSION: Early postnatal neutropenia might be an important risk factor for the development of BPD and lung injury responsible for the development of BPD might begin at the early postnatal period.

Association of Early Postnatal Neutropenia and Development of Bronchopulmonary Dysplasia in Preterm Infants

PURPOSE: To see if a similar relationship exists between the decreased number of circulating neutrophils and the development of bronchopulmonary dysplasia (BPD) in preterm infants, we tried to test the hypothesis that claims that preterm infants, who develop BPD, have decreased number of circulating neutrophils than those who do not develop BPD. METHODS: A retrospective cohort study was conducted in 167 preterm infants from August 1995 to July 1997, who were admitted in the neonatal intensive care unit (NICU) of Seoul National University Children's Hospital. RESULTS: BPD was diagnosed in 16% (27/167) of preterm infants. We compared the clinical characteristics of the study population according to the presence or absence of BPD. Compared to non-BPD group, the BPD group had a lower gestational age (29.4 +/- 2.7weeks versus 32.7 +/- 1.7 weeks), lower birth weight (1,240 +/- 486g versus 1,780 +/- 420g), lower incidence of prenatal steroid use (2/27 versus 41/140), decreased number of circulating neutrophils (3,622 +/- 4,866/microliter versus 7,586 +/- 4,545/microliter) at 1 day of life. After adjusting for the variables of the above risk factors, neutropenia (<2,500/microliter) in the peripheral blood increased the odds ratio of developing BPD (OR : 46.3, 95% CI : 17.3-117.2). CONCLUSION: Early postnatal neutropenia might be an important risk factor for the development of BPD and lung injury responsible for the development of BPD might begin at the early postnatal period.

Control of clonorchiasis by repeated praziquantel treatment and low diagnostic efficacy of sonography

In Korea, Clonorchis sinensis infection is still highly prevalent because case detection in the field is difficult and the detected cases used to be incompletely cured due to treatment failure. The present study tried to control clonorchiasis in an endemic village by repeated treatments with praziquantel every 6 months and to evaluate sonography as a diagnostic measure. By stool examinations, the egg positive rate in the endemic village was 22.7%, but it decreased to 19.6% at 6 months, 15.1% at 12 months. 12.2% at 18 months, 6.3% at 24 months, 11.4% at 30 months, and 6.3% at 42 months after the beginning of repeated praziquantel administration. The sonography showed 61 (49.6%) positive cases of 123 screened residents: among egg-positives the sonography positive rate was 52.2% and among egg-negatives it was still 49%. The rate among cured cases was 64.3% after 6 months, 50.0% after 12 months, 50.0% after 18 months, and 66.7% after 24 months. In a non-endemic village, 64 residents were found egg-negative by fecal examination, but 20 (31.3%) of them were positive by sonography. The present findings indicate that control of clonorchiasis in an endemic village by repeated praziquantel treatment for 42 months is still insufficient and sonography is of little value for diagnosis of clonorchiasis.

Neonatal Statistics of Korea in 1996: Collective Results of Live - Births , Neonatal Mortality , and Incidence of Dischage Against Medical Advice at 64 Hospitals

PURPOSE: To evaluate the nation-wide results of statistics related to the neonatal period of 1996, we collected data of a total of 64 hospitals in Korea (42 university hos- pitals and 22 general hospitals). METHODS: We obtained the results of 129,175 inboms and 9,379 outborns, and analyzed the statistics of live-births, ig, distribution of live-births by gestational age and birth weight, incidence of pre-term infants and low birth weight infants (LBWI), neonatal mortality, and incidence of discharge against medical advice (DAMA). RESULTS: According to birth weight, incidence of LBWI, normal birth weight, infant and high birth weight infants was 3.6%, 86.6% and 9.8%, respectively in the case of inborn group. But incidence of LBWI was higher in outborn group as compared with the inbom group. According to gestational age, incidence of preterm, term, and post-term was 11.1%, 87.1Yo and 1.8% respectively in the inbom group. The incidence of preterm in outborn group was higher than that of inborn group, because of the influnce of transpor- tation of high risk neonates to 2nd or 3rd levels of neonatal intensive care units (NICU). Overall neonatal mortality per 1,000 live-births was 9.3 in the inborn group amd 37.6% in the outborn group. These data revealed a high neonatal mortality, because the numbers of DAMA cases was also included. The incidence of DAMA was 0.44% and 1.15% in inborn and outborn groups, respectively. The percentage of the DAMA among the numbers of neonatal mortality was 47.2-48.8M in the inborn group. CONCLUSIONS: We obtained the statistics related to live-birth, incidence of prematurity and LBWI, neonatal mortality, and incidence of DAMA in Korea. The data revealed high levels of neonatal mortality (which included the sum of neonatal death and the number of DAMA) and incidence of DAMA in Korea at present. To achieve a low-level of neonatal mortality, more efforts to decrease the incidence of DAMA are needed. Also, a greater facility for NICU and a stronger support system from a nation-wide govemment policy and system of insurance are seen to be necessary.

Changes of Respiratory Indices and Clinical Response to the Different Modes of Delivery for Administration of Surfactant Replacement Therapy in the Respiratory Distress Syndrome

PURPOSE: Factors affecting the response to surfactant replacement therapy are considered as types of surfactant, and strategies of treatment including prophylactic vs rescue therapy, single vs multiple doses, methods of mechanical ventilation, and modes of surfactant delivery. Among those factors, response to surfactant replacement therapy according to the modes of surfactant delivery was rarely studied in the world. In preterm infants with RDS, we studied the efficacy and adverse effects of surfactant replacernent therapy according to the differences in the modes of surfactant delivery. METHOD: Preterm infant weighing 500-2,500g with RDS who required assisted ventilation were divided into two groups. One group is as follows five fractional doses with five positional changes after removal from ventilator by feeding tube technique. The other group is as follows; two fractional doses with two positional changes by side-port adaptor technique. Of the 30 infants enrolled, 15 were randomly assigned to each group. We compared the respiratory indices, chest radiologic response, clinical outcome after surfactant replacement, and adverse effects during dosing procedure. RESULT: There were no diffrences of patient profile between two groups. There were significant improvernent in FiO2, a/APO2, MAP, OI, and chest radiologic response following surfactant replacement therapy in both groups. No significant differences were noted in the adverse effects during dosing procedure and incidence of complication. CONCLUSION: In initial phase of RDS treatment with surfactant replacement therapy, two fractional doses with two positional changes by side-port adaptor technique improve respiratory indices, radiologic response without dernonstrable harmful effects as five fractional doses with five positional changes after removal from ventilator by feeding tube technique, however two fractional dosing procedure is more recommendable because of #more simple and convenient procedure.

Hemodynamic Effect of Nitric Oxide Inhalation in the Acute Hypoxic Pulmonary Hypertension Induced Newborn Piglet

Purposes : Nitric oxide (NO) is classified as toxic gas in native states, but in most biologic systems NO acts as a messenger molecule. NO is known as endothelium derived relaxing factor that modulates tone of vascular smooth muscle. Inhaled NO has been reported to act as a selective pulmonary vasodilator and we expect that NO inhalation can be used as a successful treatment modality in the management of persistent pulmonary hypertension of the newborn. We used the newborn piglet to create acute hypoxic pulmonary hypertension and examined the hemodynamic effect of inhlaled NO and dose-response characteristics in different concentrations of NO in this model. The aims of this study were to investigate the feasibility and safety of administering NO to a neonatal model and to get a useful informations about clinical applications of administering NO. METHODS: Nine 2-to 9-d-old piglets with an average weight of 3.1+/-0.86kg were anesthetized, intubated and instrumented in order to measure the hemodynamic variables. NO in nitrogen in a concentration of 800 ppm in 47 liter sylinder was obtained and injected into the inspiratory line of a time-cycled pressure-limited neonatal ventilator after reducing of pressure using 3 staged regulator. Gas mixture in downstream of the injection site was analyzed for NO and NO2 using electrochemical analyzer. Statistical analyses were done using with SAS software ver. 6.04. RESULTS: Baseline hemodynamic parameters in normoxic breathing such as mean systemic arterial pressure, mean pulmonary arterial pressure, systemic vascular resistance, pulmonary vascular resistance and cardiac index were 79+/-18mmHg, 16+/-4mmHg, 0.20+/-0.09mmHg, mL-1, min, kg, 0.04+/-0.02mmHg, mL-1, min, kg, and 399+/-201mL/min/kg respectively. Inhaling 20 and 80 ppm NO during ventilation at FIO2 0.21 did not produce any significant changes in hemodynamic indices. Pulmonary hypertension was induced by reducing the fraction of inspired oxygen to 0.10 to 0.15 and arterial oxygen saturation between 35 and 45%. The hypoxic challenge caused a significant increase in pulmonary arterial pressure, pulmonary vascular resistance and the ratio of pulmonary to systemic vascular resistance of 105% (P<0.001), 92% (P<0.02), 72% (P<0.01) respectively. Systemic arterial pressure increased by 20% (P<0.05), but systemic vascular resistance and cardiac index were not changed significantly. Inhaled NO was then administered in concentrations of 10, 20, 40, 80, and 100 parts per million in random order. All concentrations of NO were associated with a rapid decrease in pulmonary arterial pressure and pulmonary vascular resistance (P<0.02, P<0.001). The ratios of pulmonary to systemic vascular resistance decreased with all levels of inhaled NO (P<0.05). There was no significant difference between the different doses of NO in their effects. There was no significant increase in circulating methemoglobin, and the NO2 levels in the inspiratory limb of ventilator never exceeded 1.5 ppm. Plasma nitrite and nitrate increased in a dose-dependent manner (P<0.05). CONCLUSIONS: In acute hypoxic pulmonary hypertension induced newborn piglets NO inhalation with all the varying concentrations led to reduction of pulmonary arterial pressure promptly and safely without significant increase of methemoglobin and NO2 levels.

Influence of Phototherapy on Incidence of Patent Ductus Arteriosus in Very Low Birth Weight Infants

PURPOSE: Patent ductus arteriosus (PDA) is a common disease in very low birth weight infants (VLBWI). Hemodynamically significant PDA increases the morbidity and mortality of premature infants. Based on experimental model, light inhibits the constriction of immature piglet's ductal rings. No specific mechanism adequately explains the effect of light on the relaxation of PDA. Several hypotheses, including activation of photosensitive metabolites, alterations in receptors, or alterations in prostaglandin metabolism, have been postulated. The purpose of this study was to evaluate the influence of phototherapy on incidence of PDA in VLBWI. Mehtods : Sixty-three infants with birth weights less than 1,500 gm from March 1994 to February 1996 who were admitted in NICU of Seoul National University Children's Hospital were included. Thirty-four infants from March 1995 to February 1996 were shielded with aluminium foils on left chest during phototherapy (Shield group) and twenty-nine infants from March 1994 to February 1995 were not shielded (No shield group : control group). We investigated the incidence and the perinatal risk factors of PDA. RESULTS: 1) The incidence of PDA was 18% in shield group and 41% in control group. There was statistically significant between the two groups (P<0.05). 2) There was not statistically significant between two groups with gestational age, birth weight, sex, delivery mode, etc. 3) The perinatal risk factors which were statistically significant were group and presence of respiratory distress syndrome (RDS), and use of artificial surfactant. With linear logistic regression analysis, only group (OR=8.3, 95% CI=1.17-58.69) and presence of RDS (OR=21.3, 95% CI=1.39-329.81) were proved to be related to the occurrence of PDA. CONCLUSIONS: We conclude that chest shielding during phototherapy is a simple and inexpensive method to decrease the incidence of PDA.

A case of Adenovirus Infection in the Neonate

Adenovirus is an important etiologic agent in the pediatric population with fever and respiratory disease, but in newborn period, it has been known rarely to cause illness. But, its tendency of dissemination in immunocompromized host makes the neonate a high risk group of severe adenoviral infection. A newborn girl who presented with pneumonia, pulmonary hemorrhage, hepatitis, and disseminated intravascular coagulation continued to deteriorate in spite of the antibiotic therapy and maximal ventilatory support. The autopsy revealed adenoviral infection in the lung by electron microscopy. Adenoviral infection should be also suspected when a newborn infant has pneumonia, hepatitis, neurologic symptoms, and disseminated intravascular coagulation and especially his or her bacterial culture results are negative.