• Journal of Preventive Medicine and Public Health
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• v.25 no.1 s.37
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• pp.34-43
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• 1992

To investigate the effect of hyperoxia on EKG findings and to evaluate the applicability of EKG as noninvasive monitoring index of oxygen toxicity, 38 rabbits were continuously exposed to 6 different conditions-3 hyperbaric oxygenations (HBO-2.5, 3.5 and 5ATA, 100% $O_2$), normobaric oxygenation (NBO,100% $O_2$), hyperbaric aeration (HBA-5ATA, 21% $O_2$) and normobaric aeration (NBA, 21% $O_2$)-for 120 minutes and their EKG and time to dyspnea and convulsion were recorded. Dyspnea and death were observed in exposure conditions of HBO-3.5 and HBO-5 (Positive rate of dyspnea 10%, 100%, death : 10%, 25%, respectively) only, and convulsion in 4 oxygenation groups (NBO;20%, HBO-2.5;20%, HBO-3.5;20%, HBO-5;88%). Abnormal EKG findings included arrhythmia and ST-T changes and the incidences was increasing with doses(partial pressure of oxygen). In addition to EKG change, findings observed during exposure were dyspnea and convulsion in the order of appearance and when non specific ST-T change was accepted as positive(abnormal) finding, the frequency of abnormal EKG was statistically significant(p<0.01), but when it was excluded from positive results, the frequency of EKG change was not significant(p>0.05). These results suggest that the effect of hyperoxia on heart is myocardial ischemia and arrhythmia, that oxygenation more than 3.5ATA causes myocardial damage in 120 minutes exposure, and that EKG is valuable as monitoring index of oxygen toxicity.

• Journal of Trauma and Injury
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• v.27 no.4
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• pp.229-232
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• 2014

A 55 year-old man hit a vehicle while riding a bicycle. He was diagnosed as left hemopneumothorax, multiple rib fracture, cerebral hemorrhage, and skull fracture. Initially he suffered from hypoxia requiring 100% oxygen with a mechanical ventilator. Finally he became hypotensive. Venovenous extracorporeal membrane oxygenation (ECMO) was initiated to support patient's gas exchange. Because hypotension and left ventricular dysfuction persisted, we converted the mode of support to veno-arterio-venous ECMO. Over four days of intensive care, we could wean off ECMO. The patient went to rehabilitation facility after 45 days of hospitalization. Although trauma and bleeding are considered as relative contraindication of ECMO, careful decision making and management may enable us to use ECMO for trauma-related refractory heart and/or lung failure.

• Journal of Chest Surgery
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• v.32 no.1
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• pp.53-57
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• 1999

We describe a case of successful extracorporeal membrane oxygenation(ECMO) in a small infant with cardiopulmonary resuscitation(CPR) failure after an open heart surgery. A 35-day-old male infant weighing 4.4 kg who had congestive heart failure and pulmonary hypertension underwent patch closure of ventricular septal defect without any intraoperative event. Postoperative course was unremarkable in the intensive care uint for about 5 hours before the junctional ectopic tachycardia developed. Sudden cardiac decompensation with bradycardia occurred about 50 minutes after the development of junctional ectopic tachycardia. He was put on ECMO by arterial cannulation at the ascending aorta and by venous cannulation at the right atrial appendage after 4 hours' CPR. The hemodynamics were stable with enough urine output during ECMO. He was weaned from ECMO 38.5 hours after initiation. Delayed sternal closure was attempted. He was extubated on postoperative day 7 and discharged home on postoperative day 21 without any neurologic sequelae.

• Journal of Chest Surgery
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• v.25 no.2
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• pp.125-130
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• 1992

To evaluate the effect of oxygenation[95% O2+5% CO2] of St. Thomas Hospital No.2 cardioplegic solution[Plegisol], 20 isolated perfused rat hearts were studied under hyp-othermic[20oC] ischemic arrest for 2 hours with infusion of cardioplegic solution every 30 minutes throughout the ischemic period. Ten isolated hearts were studied with the oxygenated cardioplegic solution and 10 another isolated hearts with the nonoxygenated one. Mean oxygen tensions of the nonoxygenated and oxygenated cardioplegic solutions were 150mmHg and 470mmHg, respectively. Two in 10 hearts infused with the nonaxygenated cardioplegic solution were not recovered from nonworking heart due to persistent ventricular fibrillation. In comparing hem-odynamic parameters between both groups, the mean postischemic recovery[expressed as a percentage of its preischemic control value] was significantly greater with the oxygenated solution[in 10 recovered hearts] than the nonoxygenated solution[in 8 recovered hearts] [95.9$\pm$1.8% compared with 88.5$\pm$2.9% in peak aortic pressure, p<0.05, 75.7$\pm$5.2% compared with 43.5$\pm$6.5% in aortic flow, p<0.01, 75.5$\pm$4.6% compared with 54.1$\pm$5.6% in cardiac output, p<0.01, 78.3$\pm$4.6% compared with 60.3$\pm$4.6% compared with 60.3$\pm$6.2% in stroke volume, p<0.05, and 80.4$\pm$5.3% compared with 58.6$\pm$7.0% in dP/dT, p<0.05]. It is concluded that oxygenation of St. Thomas Hospital No.2 cardioplegic solution improves cardiac electrical stability and postischemic hemodynamic recovery after ischemic arrest in the isolated perfused rat heart.

• Transactions on Electrical and Electronic Materials
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• v.3 no.3
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• pp.21-24
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• 2002

Two kinds of $Nd_{1+X}Ba_{2-X}Cu_3O_{7-{\delta}}$, the sintering samples and zone melting samples, were heat-treated under pure Ar at 950$^{circ}C$. The substitution of Nd ion for Ba ion in the $Nd_{1+X}Ba_{2-X}Cu_3O_{7-{\delta}}$ before and after the heat treatment was investigated by XRD. In order to confirm the effects of the heat treatment, the Tc and Jc of samples with/without the heat treatment under Ar were comparatively studied. $Nd_{1+X}Ba_{2-X}Cu_3O_{7-{\delta}}$ samples were oxygenated under pure oxygen at $300^{circ}C$. From the XRD pattern it was found that the sample with x<0.4 was transferred from tetragonal phase to orthorhombic phase after the oxygenation, while the sample with x>0.4 did not show the phase transition even after a long time oxygenation. Therefore, the low oxygen partial pressure (Ar+1 % O$_2$) was used for the ambient atmosphere of the zone-melting samples, which could reduce the melting temperature and depress the substitution of Nd for Ba. After the improvement in the zone-melting process, the Jc value was increased to 2 x $10^4$A/$cm^2$ (0 T, 78 K). The particle orientation and the structure of zone-melted NdBaCuO were studied by the XRD and SEM analysis.

• Archives of Plastic Surgery
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• v.38 no.5
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• pp.585-589
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• 2011

Purpose: Microcirculation of diabetic patients is commonly comporomised, regardless of the condition of the macrocirculation. Therefore, direct tissue oxygenation measurement is recommended in determining tissue viability and predicting wound healing potential. This study was designed to determine cut-off value of the tissue oxygenation in predicting wound healing in diabetic foot patients. Methods: This study included 41 feet of 41 diabetic foot patients who were treated in the Diabetic Wound Center of author's institution between January and June, 2009. Main inclusion criteria were type 1 or 2 diabetes and a foot ulcer (duration > 3 weeks) and ulcer area (from 1 $cm^2$ to 4 $cm^2$). Measurements of the area of diabetic foot ulcer were carried out before treatment. Transcutaneous oxygen pressure ($TcpO_2$) was measured at adjacent site of ulcer. The healing wound was defined as complete wound closure within 12 weeks. Results: Average diabetic foot ulcer areas with healing and nonhealing wounds were $2.67{\pm}0.76$ and $2.59{\pm}0.75\;cm^2$, respectively. There was no significant difference in the wound area between the groups. Average foot $TcpO_2$ in healing and nonhealing wounds were $68.56{\pm}23.07$ and $30.98{\pm}16.66$ mmHg, respectively ($p$ <0.01). The rate of healing wound increased as $TcpO_2$ increased. In particular, $TcpO_2$ lower than 40 mmHg and higher than 40 mmHg showed the most significant difference (wound healing rates of 25% and 71%, respectively). Conclusion: Based on the results of the study, the minimal $TcpO_2$ value thought to be required for adequate wound healing in diabetic wounds (cut-off value) is 40 mmHg.

• Journal of Trauma and Injury
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• v.34 no.3
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• pp.162-169
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• 2021

Purpose: For severe lung injuries or acute respiratory distress syndrome that occurs during critical care due to trauma, extracorporeal membrane oxygenation (ECMO) may be used as a salvage treatment. This study aimed to describe the experiences at a single center with the use of ECMO in trauma patients. Methods: We enrolled a total of 25 trauma patients who were treated with ECMO between January 2015 and December 2019 at a regional trauma center. We analyzed and compared patients' characteristics between survivors and non-survivors through a medical chart review. We also compared the characteristics of patients between direct and indirect lung injury groups. Results: The mean age of the 25 patients was 45.9±19.5 years, and 19 patients (76.0%) were male. The mean Injury Severity Score was 26.1±10.1. Ten patients (40.0%) had an Abbreviated Injury Scale (AIS) 3 score of 4, and six patients (24.0%) had an AIS 3 score of 5. There were 19 cases (76.6%) of direct lung injury. The mortality rate was 60.0% (n=15). Sixteen patients (64.0%) received a loading dose of heparin for the initiation of ECMO. There was no significant difference in heparin use between the survivors and non-survivors (70% in survivors vs. 60% in non-survivors, p=0.691). When comparing the direct and indirect lung injury groups, there were no significant differences in variables other than age and ECMO onset time. Conclusions: If more evidence is gathered, risk factors and indications will be identified and we expect that more trauma patients will receive appropriate treatment with ECMO.

• Neonatal Medicine
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• v.28 no.1
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• pp.14-21
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• 2021

Purpose: Premature infants have immature respiratory control and cerebral autoregulation. We aimed to investigate changes in cerebral oxygenation during apnea with and without peripheral oxygen desaturation in premature infants. Methods: This prospective observational study was conducted at Inha University Hospital. Near-infrared spectroscopy (NIRS)-monitored regional cerebral oxygen saturation (rScO₂) and pulse oximeter-monitored peripheral oxygen saturation (SpO₂) were assessed during the first week of life in 16 stable, spontaneously breathing preterm infants. Apneic episodes that lasted for ≥20 seconds or were accompanied by desaturation or bradycardia were included for analysis. The average rScO₂ value during the 5-minute prior to apnea (baseline), the lowest rScO₂ value following apnea (nadir), the time to recover to baseline (recovery time), the area under the curve (AUC), and the overshoot above the baseline after recovery were analyzed. Results: The median gestational age and birth weight of the infants were 29.2 weeks (interquartile range [IQR], 28.5 to 30.5) and 1,130 g (IQR, 985 to 1,245), respectively. A total of 73 apneic episodes were recorded at a median postnatal age of 2 days (IQR, 1 to 4). The rScO₂ decreased significantly following apneic episodes regardless accompanied desaturation. There were no differences in baseline, nadir, or overshoot rScO₂ between the two groups. However, the rScO₂ AUC for apnea with desaturation was significantly higher than that for apnea without desaturation. Conclusion: Cerebral oxygenation can significantly decrease during apnea, especially when accompanied by reduced SpO₂. These results add the evidence for the clinical utility of NIRS in monitoring premature infants.

• Journal of Chest Surgery
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• v.54 no.1
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• pp.36-44
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• 2021

Background: Extracorporeal membrane oxygenation (ECMO) has become increasingly accepted as a life-saving procedure for patients with severe acute respiratory distress syndrome (ARDS). This study investigated the relationship between cumulative fluid balance (CFB) and outcomes in adult ARDS patients treated with ECMO. Methods: We retrospectively analyzed the data of adult ARDS patients who received ECMO between December 2009 and December 2019 at Korea University Anam Hospital. CFB was calculated during the first 7 days after ECMO initiation. The primary endpoint was 28-day mortality. Results: The 74 patients were divided into survivor (n=33) and non-survivor (n=41) groups based on 28-day survival. Non-survivors showed a significantly higher CFB at 1-7 days (p<0.05). Cox multivariable proportional hazard regression revealed a relationship between CFB on day 3 and 28-day mortality (hazard ratio, 3.366; 95% confidence interval, 1.528-7.417; p=0.003). Conclusion: In adult ARDS patients treated with ECMO, a higher positive CFB on day 3 was associated with increased 28-day mortality. Based on our findings, we suggest a restrictive fluid strategy in ARDS patients treated with ECMO. CFB may be a useful predictor of survival in ARDS patients treated with ECMO.

• Journal of Chest Surgery
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• v.54 no.1
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• pp.17-24
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• 2021

Background: Although extracorporeal membrane oxygenation (ECMO) is generally performed percutaneously, the technology is deployed under sedation and necessitates endotracheal intubation. However, in some patients, the use of venoarterial (VA) ECMO without intubation may be beneficial. Herein, we describe our experiences with VA ECMO performed without prior endotracheal intubation. Methods: A total of 783 patients treated with VA ECMO at a single center between January 2013 and July 2018 were reviewed retrospectively. We included patients who underwent successful VA ECMO implementation without prior endotracheal intubation, and excluded those who were younger than 18 years, had ongoing cardiopulmonary resuscitation status, and had poor quality of the vessels needed for percutaneous cannulation. The primary study outcome was in-hospital survival. Results: In total, 50 patients were included in this study, 94% of whom showed cardiogenic shock. The mean age of the study participants was 56.3±14.5 years. The median VA ECMO support time was 7 days (range, 2-13 days). Twenty-one patients (42%) did not receive ventilator care during the VA ECMO support period, while 29 patients (58%) progressed to intubation after VA ECMO implementation. The rates of survival at discharge and weaning success were 82% (n=41) and 92% (n=46), respectively, and 80% (n=40) of patients presented good Glasgow-Pittsburgh Cerebral Performance Categories scores at discharge. Conclusion: Even in patients with cardiogenic shock, percutaneous VA ECMO can be introduced safely without prior endotracheal intubation by an experienced care team. The application of nonintubated VA ECMO might be a feasible strategy in selected cases.