PURPOSE: The ratio of time to peak velocity(AT) and right ventricular ejection time(ET) as measured from the pulmonary artery Doppler waveform showed a close inverse correlation with pulmonary arterial pressure. The purpose of this study was to see the pattern of change in pulmonary arterial pressure assessed by AT/ET in preterm infants with respiratory distress syndrome (RDS). METHODS: The changes in pulmonary arterial pressure were assessed by serial AT/ET measurements in 18 preterm infants with RDS. RESULTS: The mean AT/ET was significantly lower in the acute phase of RDS. The pattern of change in AT/ET during recovery from RDS fell into three groups. In group 1(n=11), there was a normalization of AT/ET. Four infants showed a rapid normalization of the ratio within 24 hours of the oxygen requirements falling and the remaining 7 showed a delayed normalization. In group 2(n=4), AT/ET did not rise into the normal range during the time of study. All of the infants developed bronchopulmonary dysplasia(BPD). In 2 of the 4 infants, the ratio rose towards the normal range in the early recovery phase, but fell as the recovery period continued whereas in the remaining 2, the ratio remained at a consistent low level throughout the recovery period. One infant died of severe BPD at 36 days of age and 3 were breathing air at the time of discharge. In group 3(n=3), AT/ET decreased during a relatively short period, leading to death in all infants. CONCLUSION: Pulmonary hypertension in the acute phase of RDS is usually normalized during the recovery period. In infants who develop BPD, however, pulmonary pressure persistently remains high and in those with mortality, it is aggravated during a short-term interval.
Arterial Pressure* ; Echocardiography* ; Humans ; Hypertension, Pulmonary ; Infant ; Infant, Newborn ; Infant, Premature* ; Mortality ; Oxygen ; Pulmonary Artery ; Reference Values ; Respiration

No abstract available.
Down Syndrome* ; Leukemia, Megakaryoblastic, Acute*

Medical radiation is a very important part of modern medicine, and should be only used when needed and optimized. Justification and optimization of radiation examinations must be performed. The first step of reduction of medical exposure is to know the radiation dose in currently performed examinations. This review covers radiation units, how various imaging modalities report dose, and the current status of radiation dose reports and legislation. Also, practical tips that can be applied to clinical practice are introduced. Afterwards, the importance of radiology exposure related education is emphasized and the current status of education for medical personal and the public is explained, and appropriate education strategies are suggested. Commonly asked radiation dose related example questions and answers are provided in detail to allow medical personnel to answer patients. Lastly, we talk about computerized programs that can be used in medical facilities for managing patient dose. While patient dose monitoring and management should be used to decrease and optimize overall radiation dose, it should not be used to assess individual cancer risk. One must always remember that medically justified examinations should always be performed, and unneeded examinations should be avoided in the first place.
Humans ; *Radiation Dosage ; Radiation Protection ; Radiation, Ionizing ; Tomography, X-Ray Computed

PURPOSE: An umbilical arterial catheter (UAC) in the high position reduces the lumen of the aorta and may thereby impair blood supply to the intestine. Effects of UAC on intestinal blood flow were investigated. METHODS: With the measurement of the aortic diameter, pulsed Doppler ultrasonography was performed in 23 fasting newborns to measure blood flow velocities (peak systolic velocity, end-diastolic velocity, mean velocity, time velocity integral and resistive index) in the celiac trunk (CT) and the superior mesenteric artery (SMA) before and after removal of the UAC in the high position. RESULTS: UAC reduced the cross-sectional area of the aorta by 3.5-15.0% (mean 7.5%), with the percentage of reduction being inversely related to birth weight (r=-0.86, P<0.0001). Blood flow velocities in the CT and the SMA did not change significantly after removal of the UACl left in place for 7 days. There were also no differences in blood flow velocities pre- and postremoval of the UAC which stayed in place for 17.3 days and caused a mean aortic obstruction of 11.7%. However, a longer indwelling time of the UAC may lead to a higher velocity in the CT with UAC in place, as reflected by a correlation by multiple regression analysis (r=0.42, P=0.045). CONCLUSION: Although UAC remaining in place for up to 2 weeks in fasting newborns does not lead to direct alterations in blood supply to the intestine, the possibility of blood flow impairment to abdominal organs by prolonged use cannot be excluded.
Aorta ; Birth Weight ; Blood Flow Velocity ; Catheterization* ; Catheters* ; Fasting ; Hemodynamics* ; Humans ; Infant, Newborn ; Intestines ; Mesenteric Artery, Superior ; Ultrasonography, Doppler, Pulsed

No abstract available.
Truncus Arteriosus*

PURPOSE: Percutaneous closure with occluding coils has been recently described as a method of nonsurgical treatment of the small patent ductus arteriosus (PDA). The snare-assisted technique or detachable coil has been newly developed, improving coil delivery and eliminating the incidence of coil embolization. This method is also applicable to residual PDA following surgical ligation or device implantation. The study purpose is to discuss our experience with percutaneous closure of the small patent ductus arteriosus by occluding coils. METHODS: Between February 1995 and September 1996, 41 patients underwent coil occlusion. Thirty-one patients had native PDAs and 10 residual PDAs. Mean age was 5.0 +/- 3.2 years (1.5 to 14.0 years), and mean body weight 18.0 +/- 7.2kg (8.7 to 45kg). Mean ductal diameter was 1.9 +/- 0.6mm (1.0 to 3.5mm). Occlusion was performed by using the snare technique in 34 patients and by using a detachable coil in 6 patients. Follow-up was done at week 1, 3, 6, and a 12-month postprocedure was dont by echocardiography. RESULTS: Of the 41 patients with successful coil implantation, 32 patients (78%) had no residual shunting, 8 trace residual shunting, and 1 small residual shunting shown by angiogram immediately after coil embolization. All the patients except for one were followed up for 6.5 +/- 4.5 months (1 day to 12 months). Complete closure was confirmed in 38 patients (95%) at 6 months after implantation (34/40 at 1 month, 37/40 at 3 months, 38/40 at 6 months). There were no significant complications. CONCLUSION: Percutaneous occlusion of PDA can be safely and effectively performed in patients with small PDA, irrespective of native or residual nature, by using the snare technique or a detachable coil.
Body Weight ; Ductus Arteriosus, Patent* ; Echocardiography ; Embolization, Therapeutic* ; Follow-Up Studies ; Humans ; Incidence ; Ligation ; SNARE Proteins

PURPOSE: The adverse reactions of prostaglandin E1(PGE1) are troublesome in the preoperative management of critical patients with ductus dependent congenital heart disease, and a preparation with less adverse reactions is preferable. The effects of Lipo PGE1, a new preparation of PGE1 contained in lipid microspheres, were compared with those of conventional PGE1(PGE1-CD). METHODS: Lipo PGE1 was infused at a rate of 5 ng/kg/min in 19 patients, PGE1-CD at a rate between 10 and 50 ng/kg/min in 15 patients. The effects of drugs were assessed in terms of clinical response rate and overall safety. RESULTS: Clinically, both treatment were effective in relieving cyanosis and hypoxemia except in patients already having either a closed ductus or severe hypoxemia and acidosis. The increments of PaO2 1 hour after infusion were 10.9 and 6.2 mmHg (p>0.1), respectively and those 4 hours postinfusion were 16.0 and 7.8 mmHg(p<0.05), respectively. Even though there was no significant difference in clinical response rate(78.9 vs 60.0%, p>0.1), the mean dose of Lipo PGE1 at appearance of response was about 1/5 of that of PGE1-CD in overall patients and also in patients with ductus dependent pulmonary circulation(6.7 vs 31.7 ng/kg/min, p<0.005). The adverse reactions occurred in 52.6% of the patients given Lipo PGE1, while it was 86.7% in those administered PGE1-CD(p<0.05). The adverse reactions in Lipo PGE1 group was much less severe than that in PGE1-CD group. There was a significant difference in overall safety between the two drugs(84.2 vs 40%, p<0.01). As the incidence of the adverse reactions increased at dose over 5 ng/kg/min, the initial dose of 5 ng/kg/min seemed to be appropriate for Lipo PGE1. CONCLUSIONS: Lipo PGE1 was effective at a lower dose than was PGE1-CD, and was associated with fewer or less severe adverse reactions, and is therefore judged to be more suitable for clinical use than conventional PGE1-CD.
Acidosis ; Alprostadil ; Anoxia ; Cyanosis ; Heart Defects, Congenital* ; Humans ; Incidence ; Microspheres

No abstract available.
Angioplasty* ; Child* ; Humans ; Takayasu Arteritis*

Air reduction is a safe, effective, and fast initial treatment for pediatric intussusception. There is low dose radiation exposure. Factors affecting outcomes of air reduction were analyzed by reviewing the clinical features and results of treatment. A total of 399 out of 485 patients with pediatric intussusceptions were treated at the Seoul National University Children's Hospital from 1996 to 2009. All of the patients received air reduction as the first line of treatment. Clinical features such as gender, age, seasonal variation, symptoms, signs, types, pathologic leading point, and treatment results including success rate, complication, recurrence, NPO time, and duration of hospitalization were reviewed. The Pearson chi-square, student T-, and logistic regression tests were used for statistical analysis. P-value less than 0.05 was considered to be statistically significant. The prevalent clinical features were: male (65.4%), under one-year of age (40.3%), ileocolic type (71.9%), abdominal pain (85.4%), and accompanying mesentery lymph node enlargement (2.2%). The overall success rate for air reduction was 78.4% (313 of 399 patients), and the perforation rate during reduction was 1.5%. There were 23 recurrent cases over 21.6 months. All were successfully treated with re-do air reduction. Reduction failures had longer overall NPO times (27.067hrs vs. 43.0588hrs; p=0.000) and hospitalization durations (1.738d vs. 6.975d; p=0.000) compared to the successful cases. The factors affecting success rates were fever (p=0.002), abdominal distension (p=0.000), lethargy (p=0.000) and symptom duration (p=0.000) on univariate analysis. Failure rates were higher in patients with symptom durations greater than 24 hours (p=0.023), and lethargy (p=0.003) on multivariate analysis. Air reduction showed high success rates and excellent treatment outcomes as the initial treatment for pediatric intussusception in this study. Symptom duration and lethargy were significantly associated with reduced success rates.
Abdominal Pain ; Fever ; Hospitalization ; Humans ; Intussusception ; Lethargy ; Logistic Models ; Lymph Nodes ; Male ; Mesentery ; Multivariate Analysis ; Recurrence ; Seasons

Peritoneal dialysis (PD) has been utilized for the children with end stage renal disease. Nevertheless, it is thought to promote inguinal hernia by increasing intraabdominal pressure. To investigate the clinical characteristics of inguinal hernia in children on PD, 155 cases of PD in children between January 1996 and June 2007 at Seoul National University Children's Hospital were reviewed retrospectively. Inguinal hernia developed in 16 cases (10.3%, M:F=8:8). Hernia occurrence was not correlated to age. Eleven cases (69%) of inguinal hernia developed in first 6 months after initiation of PD. All inguinal hernias were surgically repaired. No complications occurred related to inguinal hernia or surgery. Recurrent hernia developed in 1 patient (6.3%) of 2 cases who had PD postoperatively on the day of surgery. In conclusion, inguinal hernia developed more frequently with children on PD than general population (3.5~5%). The rate of hernia development was highest within the first 6 months following initiation of PD. After repair of hernia, we recommend to discontinue PD immediate postoperatively to prevent recurrence.
Child ; Hernia ; Hernia, Inguinal ; Humans ; Kidney Failure, Chronic ; Peritoneal Dialysis ; Retrospective Studies