Determination of the neutron fluence spectra in the neutron therapy room of KIRAMS.

High energy proton induced neutron fluence spectra were determined at the Korea Institute of Radiological and Medical Sciences (KIRAMS) using an extended Bonner Sphere (BS) set from the Korea Atomic Energy Research Institute (KAERI) in a series of measurements to quantify the neutron field. At the facility of the MC50 cyclotron of KIRAMS, two Be targets of different thicknesses, 1.0 and 10.5 mm, were bombarded by 35 and 45-MeV protons to produce six kinds of neutron fields, which were classified according to the measurement position and the use or no use of a beam collimator such as the gantry of the neutron therapy unit. In order to obtain a priori information to unfold the measured BS data the MCNPX code was used to calculate the neutron spectrum, and the influence of the surrounding materials for cooling the target assembly were also reviewed through this calculation. Some dosimetric quantities were determined by using the spectra determined in this measurement. Dose equivalent rates of these neutron fields ranged from 0.21 to 5.66 mSv h(-1)nA(-1) and the neutron yields for a thick Be target were 3.05 and 4.77% in the case of using a 35 and a 45-MeV proton, respectively.

[Ventricular late potentials in patients with diabetes mellitus].

Ventricular late potentials (VLP) was measured in 31 normal subjects, 31 coronary heart disease (CHD) patients and 31 diabetic patients whose ECG and UCG were normal. Matched control study was used. The result revealed that the positive rates of VLP of CHD group (45.16%) was significantly higher than that of diabetic group without clinical cardiomyopathy (19.35%, P < 0.05), and diabetic group was significantly higher than that of normal subjects (0%, P < 0.05). Although electrocardiogram and echocardiography were normal in all the diabetic patients, the VLP positive rate was 19.35%. Experimental and clinical studies had shown a positive correlation between the duration of late potentials, malignent ventricular arrhythmia and sudden cardiac death so that measurement of VLP might be a new and valuable technique to detect subclinical diabetic cardiomyopathy, and to predict ventricular arrhythmia attack and sudden cardiac death in diabetic patients.

The experience of two-epidural-catheter for painless labor.

'Two epidural-catheters' method was used to relieve labor pain during the first and second stage of labor course. Six milliliters of a mixture of '0.15% bupivacaine +0.03% xylocaine +0.0005% fentanyl' was the main agent given through the epidural catheter every 2 hours when the cervix was 3-4 cm dilated with 4 ml of 1% xylocaine as test dose. Addition doses of the mixture were given when needed. Fifty two, ASA I-II, parturients (primigravida: 43, multipara: 9) were included in this study. The mode of delivery was: 59.6% by vacuum, 36.4% by normal spontaneous delivery (NSD), and 4% by Cesarean Section (C/S). 88.5% of newborns had Apgar score > or = 7 at 1 minute and all had Apgar score > or = 7 at 5 minutes. 38(73%) of 52 parturients were fully satisfied with the analgesic effect during the whole labor course and 14(27%) of 52 parturients were partially satisfied with the analgesic effect owing to 1) intolerable lower abdominal pain (11 cases), 2) mild painful episiotomy (1 case), and backache (2 cases). No motor block was noted. Good analgesic effect during the second stage labor course could be obtained by our 'Two-Epidural-Catheter' method and no significant complications of newborns and parturients were noted in our study.

Is routine preanesthetic hemoglobin test necessary in minor pediatric surgery?

The value of preanesthetic assessment of anemia and analysis of the hemoglobin level prior to a minor pediatric surgery has been recently questioned in some reports. This study was to retrospectively analyse 8859 pediatric patients who underwent minor surgery in the period from January 1987 to December 1990 in our hospital. They were all ASA class I-II in physical status with age ranging from one month to 19 years. Those patients with their hemoglobin values determined at other laboratories or hospitals in spite of our recognition and those suspected of having an immune or oncologic disease were excluded from this study. The mean hemoglobin value of the patients under study was 12.99 +/- 0.82 g/dl. 0.62% of the patients (55) were found to have hemoglobin values less than 10 g/dl which were similar to the results obtained by Wood et al (0.7%) in 1981 and Roy et al (0.5%) in 1990. Among the 55 anemic patients, 41 (74.5%) were at the age between 2 to 4 months (within the physiologic anemic period of infancy). Sampling of blood for routine preanesthetic hemoglobin determination which caused discomfort and pain was often rejected by pediatric patients and struggle for escape also upset the children very much. Based on the results from our analysis, we suggest that in healthy pediatric patient scheduled for minor surgery routine hemoglobin test could be excluded. Hemoglobin test is selectively performed in a patient is anemic or under suspicious circumstances. The value and shortcomings of selective hemoglobin test before surgery require further evaluation.