• Clinical and Experimental Pediatrics
• /
• v.48 no.10
• /
• pp.1096-1101
• /
• 2005

Purpose : Recently, early surfactant replacement and tidal volume based gentle ventilation has been a fundamental treatment of respiratory distress syndrome(RDS). The aims of this study were to survey the changes in ventilator care duration and rate of complication in RDS groups. Methods : We performed a retrospective study of 255 newborn infants less than 1,500 g admitted to the neonatal intensive care unit(NICU) and discharged from January 1999 to December 2003. 141 of 255 newborn infants were RDS groups that required invasive management, such as endotracheal intubation, surfactant replacement and assisted ventilation. We analyzed epidemiologic data to study the changes in ventilator care duration and outcome of RDS groups. Results : Of 141 RDS groups, 135 were mild to moderate RDS groups and only 6 were severe RDS groups. 24(17.8%) of 135 mild to moderate RDS groups and 3(50%) of 6 severe RDS groups were antenatal no use of maternal dexamethasone. 127(90.1%) of 141 RDS groups underwent replacement of surfactant during 3 hours after birth. 121(85.9%) weaned within 48 hours. Conclusion : Our study shows a decreased frequency of severe RDS by a antenatal use of maternal dexamethasone and decreased duration of ventilator care by early surfactant replacement and gentle ventilation.

• Clinical and Experimental Pediatrics
• /
• v.46 no.11
• /
• pp.1073-1079
• /
• 2003

Purpose : Recently there has been a decrease in ventilator care rate and duration of very low birth weight infants(VLBWI) in Fatima Hospital. The aims of this study were to survey the frequency and duration of ventilation in VLBWI and to develop a non-invasive neonatal intensive care unit (NICU) policy. Methods : We performed a retrospective study of 284 newborn of infants less than 1,500 gm admitted to NICU and discharged from January 1998 to December 2001. Patients were intubated or applied continuous positive airway pressure(CPAP) via nasal prong immediately after presenting signs of respiratory distress. We analyzed epidemiologic data to study the changes in ventilator care rate, duration and outcome of ventilator care groups. Results : Of 284 newborn infants, 146 required invasive management, such as endotracheal intubation and assisted ventilation. The characteristics, the severity of clinical symptoms and laboratory findings in ventilator care groups at birth showed no significant differences. The annual proportion of infants requiring assisted ventilation decreased according to increasing gestational age. The median duration of ventilation decreased markedly from 6.0 days in 1998 to 2.7 days in 2001. Final complications and outcomes in ventilator care groups showed no significant differences. Conclusion : Our study shows a significant reduction in the invasiveness of the treatment of VLBW infants, which was not associated with an increased mortality or morbidity. A non-invasive strategy for the VLBW infant with minimal to moderate respiratory distress after birth in NICU is better than immediate invasive management. Non-invasive nasal CPAP is a simpler and safer method than invasive assisted ventilation.

• Progress in Medical Physics
• /
• v.24 no.1
• /
• pp.76-83
• /
• 2013

Previous studies about effect of respiratory motion on diagnostic imaging and radiation therapy have been performed by monitoring external motions but these can not reflect internal organ motion well. The aim of this study was to develope the artificial pulmonary nodule able to perform non-invasive implantation to dogs in the thorax and to evaluate applicability of the model to respiratory motion studies on PET image acquisition and radiation delivery by phantom studies. Artificial pulmonary nodule was developed on the basis of 8 Fr disposable gastric feeding tube. Four anesthetized dogs underwent implantation of the models via trachea and implanted locations of the models were confirmed by fluoroscopic images. Artificial pulmonary nodule models for PET injected $^{18}F$-FDG and mounted on the respiratory motion phantom. PET images of those acquired under static, 10-rpm- and 15-rpm-longitudinal round motion status. Artificial pulmonary nodule models for radiation delivery inserted glass dosemeter and mounted on the respiratory motion phantom. Radiation delivery was performed at 1 Gy under static, 10-rpm- and 15-rpm-longitudinal round motion status. Fluoroscpic images showed that all models implanted in the proximal caudal bronchiole and location of models changed as respiratory cycle. Artificial pulmonary nodule model showed motion artifact as respiratory motion on PET images. SNR of respiratory gated images was 7.21. which was decreased when compared with that of reference images 10.15. However, counts of respiratory images on profiles showed similar pattern with those of reference images when compared with those of static images, and it is assured that reconstruction of images using by respiratory gating improved image quality. Delivery dose to glass dosemeter inserted in the models were same under static and 10-rpm-longitudinal motion status with 0.91 Gy, but dose delivered under 15-rpm-longitudinal motion status was decreased with 0.90 Gy. Mild decrease of delivered radiation dose confirmed by electrometer. The model implanted in the proximal caudal bronchiole with high feasibility and reflected pulmonary internal motion on fluoroscopic images. Motion artifact could show on PET images and respiratory motion resulted in mild blurring during radiation delivery. So, the artificial pulmonary nodule model will be useful tools for study about evaluation of motion on diagnostic imaging and radiation therapy using laboratory animals.

• Clinical and Experimental Pediatrics
• /
• v.46 no.12
• /
• pp.1200-1206
• /
• 2003

Purpose : This study was conducted for the use of nasal continuous positive airway pressure (CPAP), by comparing the early use of non-invasive nasal CPAP with low intermittent mandatory ventilation(low IMV) and endotracheal CPAP in weaning a mechanical ventilator from infants with moderate respiratory distress syndrome(RDS). Methods : Thirty infants in the study group, with moderate RDS from November 2001 to June 2002, were administered surfactants and treated with the mechanical ventilator, and applied the nasal CPAP in weaning. Thirty infants of the control group, from January 1999 to September 2001, were applied low IMV and endoctracheal CPAP in weaning. Results : There were no significant differences in the characteristics, the severity of clinical symptoms, the initial laboratory findings and settings of the mechanical ventilator. After weaning, the study group showed no significant changes in $PaCO_2$. However, the control group showed a slight $CO_2$ retension after one and 12 hours. Twenty eight infants(93.3%) of the study group and 24 infants(80%) of the control group were successfully extubated. The primary cause of failure was apnea. There were no significant differences in the duration of weaning and the mechanical ventilator treatment between the groups. Complications in weaning were related to the fixation of nasal CPAP and the mechanical problems caused by endotracheal tube. Conclusion : Aggressive weaning is possible for moderate RDS, in which the nasal CPAP was used without the low IMV and the endotracheal CPAP process. It had no difficulties. In conclusion, the nasal CPAP is an adequate weaning method for moderate RDS.

• Tuberculosis and Respiratory Diseases
• /
• v.44 no.6
• /
• pp.1326-1331
• /
• 1997

Background : Weaning is the process of switching a patient from mechanical ventilator to spontaneous breathing. A number of different weaning techniques can be employed. At recent study, conventional spontaneous breathing trial was superior to other techniques, such as intermittent mandatory ventilation(IMV) or pressure support ventilation(PSV). But adequate observation time of the spontaneous breathing trial was not determined. We reported the effectiveness of weaning and extubation following a 60 minutes spontaneous breathing trial with simple oxygen supply through the endotrachial tube. In this study, we tried to shorten the spontaneous breathing time from 60 minutes to 30 minutes. If weaning success was predicted after 30 minutes spontaneous breathing, extubation was done without reconnection with ventilator. Methodes : Subjects consisted of 42 mechanically ventilated patients from August 1994 to July 1995. The weaning trial was done when the patients recovered sufficiently from respiratory failure that originally required ventilatory assistance, the patients became alert and showed stable vital sign, and arterial $O_2$ tension was adequated($PaO_2$ > 55 mmHg) with less than 40% of inspired oxygen fraction. We conducted a careful physical examination when the patients was breathing spontaneously through the endobronchial tube for 30 minutes. We terminated the trial if a patients was any of following signs of distress; cyanosis, diaphoresis, tachypnea(above 30 breaths per minute), and extreme tachycardia. Patients who had none of this features during spontaneous breathing for 30 minutes were extubated promptly. Result : 17 weaning trials of 15 patients were done in 42 mechanically ventilated patients. Successful weaning and extubation was possible in 14 trials of total 17 trials. In this 14 patients, 8 patients were extubated after 30 minutes spontaneous breathing, 3 patients were extubated after 60 minutes spontaneous breathing, and 3 patients needed over 3 hours for extubation from weaning. We found similar overall success rate compared with weaning following a 60 minutes spontaneous breathing trial. Conclusion : From the result of present study, we believe that weaning and extubation from mechanical ventilation following a 30 minutes spontaneous breathing with $O_2$ supply through the endotracheal tube is a simple and effective method.

• Tuberculosis and Respiratory Diseases
• /
• v.46 no.6
• /
• pp.803-810
• /
• 1999

Background : The patient's work of breathing(WOBp) during assisted ventilation may vary according to many factors including ventilatory demand of the patients and applied ventilatory setting by the physician. Pressure-controlled ventilation(PCV) which delivers gas with decelerating flow may better meet patients' demand to improve patient-ventilator synchrony compared with volume-controlled ventilation(VCV) with constant flow. This study was conducted to compare the difference in WOBp in two assisted modes of ventilation, PCV and VCV with constant flow. Methods : Ten patients with respiratory failure were included in this study. Initially, the patients were placed on VCV with constant flow at low tidal volume($V_{T,\;LOW}$)(6-8 ml/kg) or high tidal volume($V_{T,\;HIGH}$)(10-12 ml/kg). After a 15 minute stabilization period, VCV with constant flow was switched to PCV and pressure was adjusted to maintain the same tidal volume($V_T$) received on VCV. Other ventilator settings were kept constant. Before changing the ventilatory mode, WOBp, $V_T$, minute ventilation($V_E$), respiratory rate(RR), peak airway pressure (Ppeak), peak inspiratory flow rate(PIFR) and pressure-time product(PTP) were measured. Results : The mean $V_E$ and RR were not different between PCV and VCV during the study period. The Ppeak was significantly lower in PCV than in VCV during $V_{T,\;HIGH}$. HIGH ventilation(p<0.05). PIFR was significantly higher in PCV than in VCV at both $V_T$ (p<0.05). During $V_{T,\;LOW}$ ventilation, WOBp and PTP in PCV($0.80{\pm}0.37\;J/min$, $164.5{\pm}74.4\;cmH_2O.S$) were significantly lower than in VCV($1.06{\pm}0.39J/mm$, $256.4{\pm}107.5\;cmH_2O.S$)(p<0.05). During $V_{T,\;HIGH}$ ventilation, WOBp and PTP in PCV($0.33{\pm}0.14\;J/min$, $65.7{\pm}26.3\;cmH_2O.S$) were also significantly lower than in VCV($0.40{\pm}0.14\;J/min$, $83.4{\pm}35.1\;cmH_2O.S$)(p<0.05). Conclusion : During assisted ventilation, PCV with decelerating flow was more effective in reducing WOBp than VCV with constant flow. But since individual variability was shown, further studies are needed to confirm these results.

• The Journal of the Convergence on Culture Technology
• /
• v.9 no.5
• /
• pp.167-173
• /
• 2023

The purpose of this study was to analyze the accuracy of artificial respiration and chest compressions using CPR mannequins for university students. First, in the number of chest compressions, subjects A, F, H, I, and J showed similar numbers from 60 to 63, respectively, which were much lower than the standard. Subjects B, D, E, and G showed 90 to 91 times, maintaining the normal range. However, C was rather high with 119 times. Second, the depth of chest compression was 58.60mm, and most of them were deeply compressed. Subject C was close to normal at 51mm, and subjects A to J were significantly higher at 55mm to 62mm. The reason seems to be the result of an unstable psychological state with no experience of chest compressions and a lack of self-confidence. Third, in terms of accuracy, subject E showed the lowest accuracy at 12%, and A~J showed 33%~80%. Experiment subject B showed 95% accuracy, which seems to be the result of D accurately recognizing the chest compression point through theoretical training during military service.

• Tuberculosis and Respiratory Diseases
• /
• v.46 no.3
• /
• pp.363-371
• /
• 1999

Background: Because of the widespread use and availability of agricultural insecticides, acute organophosphate poisoning as a suicide or an accident is becoming the most common type of poisoning and serious problem in Korea. The mortality of organophosphate poisoning varied from 10 to 86 percent. The cause of death was thought to be a combination of excessive bronchial secretion, bronchospasm, respiratory muscle paralysis and depression of respiratory center, summarily respiratory failure. We evaluated the respiratory complications in patients with acute organophosphate intoxication to determine the predisposing, factors to respiratory failure and to reduce the incidence of respiratory failure or mortality. Method: We conducted a retrospective study of 111 patients with the discharge diagnosis of organophosphate poisoning who were hospitalized at Yenugnam University Hospital during the 5 years. The diagnosis of organophosphate poisoning has based on the followings (1) a history of exposure to an organophosphate compounds. (2) the characteristic clinical signs and symptoms. (3) decrease in the cholinesterase activity in the serum. Results: Respiratory failure developed in 31(28%) of 111 patients with acute organophosphate poisoning. All cases of respiratory failure developed within 96 hours after poisoning and within 24 hours in 23 patients. The 80 patients who did not develop respiratory failure survived. In 31 patients with respiratory failure, 15(44%) patients were dead. The patients with respiratory failure had more severe poisoning, that is, the lower level of serum cholinesterase activity on arrival, the higher mean dosage of atropine administered within first 24 hours. In 16 patients with pneumonia, 14 patients developed respiratory failure. In 5 patients with cardiovascular collapse, 2 patients developed respiratory failure. There was no correlation to between age, sex, the use of pralidoxime and respiratory failure. The serum cholinesterase level in survivors at time of respiratory failure and weaning was $66.05{\pm}85.48U/L$, $441{\pm}167.49U/L$, respectively. Conclusion: All the respiratory failure complications of acute organophosphate poisoning occurred during the first 96 hours after exposure. The severity of poisoning and pneumonia were the predisposing factors to respiratory failure. Aggressive treatment and prevention of the above factors will reduce the incidence of respiratory failure.

• Fire Science and Engineering
• /
• v.30 no.2
• /
• pp.87-91
• /
• 2016

Recently, it has been increasing an incidence of heart diseases which is a causative factor in sudden death as Korean population structure has been changing to an aging society. There is growing needs for A portable ventilator which automatically be operated by the pressure of the supplied oxygen and has been spread worldwide. So, we would like to present test methods in accordance with the performance requirements which are important for components of a respirator and a portable ventilator itself. And also would like to find the most suitable condition of internal pressure reduction for the performance requirements according to the changing conditions of internal pressure reduction setting of a portable ventilator.

• Clinical and Experimental Pediatrics
• /
• v.45 no.10
• /
• pp.1204-1212
• /
• 2002

Purpose : Early surfactant therapy with either gentle ventilation, high-frequency ventilation or aggressive weaning of mechanical ventilation are principles for the treatment of respiratory distress syndrome(RDS). We studied to determine the accessibility of noninvasive nasal continuous positive airway pressure(CPAP) rather than mechanical ventilation by invasive intubation after early surfactant therapy. Methods : The study group consisted of 14 infants who were born and diagnosed with moderate respiratory distress syndrome and received early surfactant therapy with nasal CPAP of PEEP 5-6 cm $H_2O$ within two hours after birth in the Fatima neonatal intensive care unit for two years from January 1999 to August 2001. The control group consisted of 15 infants who were diagnosed with the disease and could be weaned from mechanical ventilator within five days after birth during the same period. Results : The characteristics, the severity of clinical symptoms and laboratory findings in the two groups at birth showed no significant difference. Neither did the interim analysis of laboratory data in two groups. Of 14 infants in the study group who received nasal CPAP after early surfactant therapy, only two infants showed weaning failure with this therapy. In the response cases, duration of CPAP was five days and mean airway pressure was $5.4{\pm}0.5cm$ $H_2O$. Two had the complication of CPAP with abdominal distension. Final complications and outcomes in the two groups showed no signifcant difference(P>0.05). Conclusion : The clinical courses in the two groups showed no significant difference. Therefore, we suggest that early surfactant therapy with noninvasive nasal CPAP is a simple and safe method rather than aggressive weaning after invasive mechanical ventilation in moderate respiratory distress syndrome.