Keratoprosthesis implantation is the only alternative method to restore vision in patients who might invariably fail allograft coneal transplantation. Seoul type keratoprosthesis adapted 20 micrometer pore sized expanded polytetrafluoroethyl-ene[PTFE, Gore-Tex]as a skirt material in this study. To evaluate compatibility of this material as a skirt we performed in vitro cell culture experiment and animal experiment. For in vitro experiment, expanded PTFE membrane was cultured with rabbit keratocytes in 24-well culture plate for a week.For animal experiment Seoul type keratoprosthesis was implanted in the rabbit cornea. Two months after the operation specimens for pathologic examination were retrieved. In culture experiment no keratocyte invaded pores. In animal experiment no keratocyte but only many inflammatory cells mainly polymorphonuclear leukocytes infiltrated pores of skirt and surrounding cornea. In conclusion, 20 micrometer pore sized expanded PTFE is not good as a skirt material of keratoprosthesis.
Allografts ; Animal Experimentation ; Cell Culture Techniques ; Cornea* ; Humans ; Membranes ; Neutrophils ; Polytetrafluoroethylene ; Seoul*

BACKGROUND: Dextromethorphan (DEX) is an NMDA receptor antagonist which has recently been introduced for the treatment of chronic pain mainly to reduce the central sensitization component of pain. It is also reported to reduce the pain from acute ischemia of an extremity in a rat model which has a similar mechanism as tourniquet pain. The purpose of this experiment was to see if dextromethorphan could reduce tourniquet pain in normal volunteers. METHODS: A double blind randomized cross-over test was done on ten healthy male volunteers. Each subject was orally administered with three different doses of DEX (placebo, 30, 60 mg) 1 h before the study according to a preallocated randomized table. The subject was not reallocated for the test within two weeks of the previous test. After a 10 minute acclimation period before each test, the degree of tourniquet pain measured by VAS, arterial blood pressure, heart rate, respiration rate, and pressure-evoked pain were measured before and every 5 minutes after inflation of the tourniquet until the subject felt unbearable pain. A mixed model for repeated measurement of data was used for statistical analysis (P < 0.05). RESULTS: There was no statistical difference between different doses of DEX including the placebo. Rather, there was a tendency that DEX increases the pain. And there also was a tendency that average time to reach unbearable pain was decreased by DEX (P > 0.05). CONCLUSIONS: DEX is not effective in controlling tourniquet pain in normal awake subjects.
Acclimatization ; Arterial Pressure ; Central Nervous System Sensitization ; Chronic Pain ; Dextromethorphan* ; Extremities ; Healthy Volunteers* ; Heart Rate ; Humans ; Inflation, Economic ; Ischemia ; Male ; Models, Animal ; N-Methylaspartate ; Respiratory Rate ; Tourniquets* ; Volunteers

BACKGROUND/AIMS: Many authors recommend performing a second-look endoscopy (SLE) to reduce the frequency of delayed bleeding after endoscopic submucosal dissection (ESD) for gastric neoplasms, but these recommendations have been made despite a lack of reliable evidence supporting the effectiveness of SLE. METHODS: From January 2012 to May 2013, we investigated 441 gastric neoplasms treated by ESD to assess the risk factors for delayed bleeding. Delayed bleeding occurred in four of these lesions within 1 postoperation day. Therefore, we enrolled the patients with the remaining 437 lesions to determine the utility of SLE performed on the morning of postoperative day 2. All lesions were randomly assigned to SLE (220 lesions) groups or non-SLE (217 lesions) groups. RESULTS: Delayed bleeding occurred in 18 lesions (4.1%). A large tumor size (>20 mm) was the only independent risk factor for delayed bleeding (p=0.007). The chance of delayed bleeding was not significantly different between the patients receiving a SLE (eight cases) and those patients not receiving a SLE (six cases, p=0.787). Furthermore, SLE for lesions with a large tumor size did not significantly decrease delayed bleeding (p=0.670). CONCLUSIONS: SLE had little or no influence on the prevention of delayed bleeding, irrespective of the risk factors.
Aged ; Dissection/*adverse effects ; Female ; Gastric Mucosa/*surgery ; *Gastroscopy ; Humans ; Male ; Middle Aged ; Postoperative Hemorrhage/*prevention & control ; Prospective Studies ; Risk Factors ; *Second-Look Surgery ; Single-Blind Method ; Stomach Neoplasms/complications/*surgery ; Time Factors

PURPOSE: Myocardial scintigraphy has been reported to be useful in adults, but its usefulness in children is limited. This study was done to determine the feasibility and accuracy of 99mTc-MIBI SPECT(sestamibi , methoxy-isobutyl-isonitrarite myocardial single emirs sion computed tomography, Dp-SPECT) after dipyridamole infusion to detect coronary obstructive lesions in Kawasaki disease(KD). METHODS: Dp-SPECT was performed in 21 control(group 1), 8 with coronary aneurysm(group 2) and 16 with coronary obstructive lesion(group 3) in children with KD. The spatial distribution of Dp-SPECT was determined and analyzed visually. Group 2 and 3 underwent coronary angiogram within 3 months of Dp-SPECT. RESULTS: Chest pain occurred more frequently in group 2. No subject required supplemental oxygen or were complicated by myocardial ischemia. The specificity of Dp-SPECT for control subject was 95% & 62% if using a cut-off criterion of abnormality, utilizing moderate or mild perfusion defect, respectively. The false positive rate was high in anterior, apical and anteroseptal segments but not related to age. The abnormalities found on Dp-SPECT was observed in 25% of aneurysmal coronary arteries but not related to its size. The sensitivity, specificity, and accuracy of Dp-SPECT was 100%, 84.5% and 79% in coronary stenosis greater than 75%, respectively. CONCLUSION: The interpretation of Dp-SPECT should be careful in KD because of discrepancies between Dp-SPECT & angiography, But DP-SPECT is noninvasive and easily applicable. It monitors the occurrence and progression of coronary stenosis due to KD. Besides Dp-SPECT may be applicable after arterial switch operation or to myocardial sinusoid.
Adult ; Aneurysm ; Angiography ; Chest Pain ; Child ; Coronary Stenosis ; Coronary Vessels ; Dipyridamole ; Humans ; Mucocutaneous Lymph Node Syndrome* ; Myocardial Ischemia* ; Myocardial Perfusion Imaging ; Oxygen ; Perfusion* ; Sensitivity and Specificity

BACKGROUND: Nuss procedure used in pectus excavatum repair is preferred, because of its excellent effect from the cosmetic point of view and improved pulmonary function, but it cause severe pain due to thoracic expansion after the operation. This study was designed to evaluate effective fentanyl dose using an intravenous patient-controlled analgesia (IV-PCA) pump for pain control following pectus excavatum repair in pediatric patients. METHODS: Sixty patients undergoing elective thoracic surgery were randomly assigned to received fentanyl 0.5microgram/kg/hr (Group I, n = 20), 0.7microgram/kg/hr (Group II, n = 20), and 1.0microgram/kg/hr (Group III, n = 20) via an IV-PCA pump (basal, 1 ml/h; bolus, 0.5 ml; lock out interval, 30 min) after operation. A blind observer evaluated each patient using the Children's Hospital of Eastern Ontario pain scale (CHEOPS) and the faces scale (FS). Incidences of side effects and pain control satisfaction were assessed at postoperative 48 hrs. RESULTS: There were no significant differences in CHEOPS or FS score between the groups the postoperative 48 hrs period. CHEOPS and FS scores at 4 and 8 hrs in groups II and III were significantly lower than in group I (P<0.05), but all groups showed lower CHEOPS and FS scores during the first postoperative 48 hrs. Satisfaction of pain control assessment by mothers was significantly higher in groups II and III than in group I (P<0.05). CHEOPS and FS scores were highly correlated with each other (P<0.001). CONCLUSIONS: We conclude that infusion of fentanyl at 0.5microgram/kg/hr using an IV-PCA pump is effective for pain control of 5 years of age or older after Nuss procedure.
Analgesia, Patient-Controlled* ; Fentanyl* ; Funnel Chest* ; Humans ; Incidence ; Mothers ; Ontario ; Thoracic Surgery

BACKGROUND: Maze operation is aimed for the restoration of sinus rhythm. But restoration of atrial mechanical function has not been demonstrated in all patients converted to sinus rhythm. METHOD: From Apr. 1994 to Feb. 1996, maze operations were performed in 32 pts (M:F=13:19, mean age 47.1+/-9.0 years) combined with valvular surgery(n=26), CABG(n=3), and others(n=3). Presence of atrial mechanical function was serially examined before discharge, in 3mo, 6mo and 1 yr using Doppler echocardiography. RESULTS: In 22 patients(pts), sinus rhythm was maintained without antiarrhythmic agents. In 4 patients antiarrhythmic agent was required to maintain sinus rhythm while in another 4 patients showed paroxysmal Af despite of the treatment with antiarrhythmic agents. In 30 pts with sinus rhythm or paroxysmal Af, right atrial function was restored in all pts while left atrial function was restored in only 19/30(63%). Peak A velocity and A/E ratio were 0.38+/-0.12m/s, 0.74, respectively on tricuspid inflow(TI), and 0.46+/-0.14m/s, 0.40, respectively on mitral inflow(MI ). MI peak A velocity and A/E ratio were significantly lower than the 16 control postoperative pts (0.75<0.29, 0.80 : p+/-0.01). In pts with atrial mechanical function, the duration of Af was significantly shorter than patients without atrial function (1.9+/-2.9 yr vs 7.1+/-3.0 yr : p<0.01), but no significant differences in the LA size and volume. CONCLUSION: Maze operation is effective in restoring sinus rhythm. But restoration of sinus rhythm was not always associated with restoration of atrial mechanical function, and the restored atrial function was incomplete. The duration of Af could be a markker for predicting the restoration of atrial function.
Atrial Fibrillation ; Atrial Function ; Atrial Function, Left ; Atrial Function, Right ; Echocardiography, Doppler ; Humans

BACKGROUND: Maze operation is aimed for the restoration of sinus rhythm. But restoration of atrial mechanical function has not been demonstrated in all patients converted to sinus rhythm. METHOD: From Apr. 1994 to Feb. 1996, maze operations were performed in 32 pts (M:F=13:19, mean age 47.1+/-9.0 years) combined with valvular surgery(n=26), CABG(n=3), and others(n=3). Presence of atrial mechanical function was serially examined before discharge, in 3mo, 6mo and 1 yr using Doppler echocardiography. RESULTS: In 22 patients(pts), sinus rhythm was maintained without antiarrhythmic agents. In 4 patients antiarrhythmic agent was required to maintain sinus rhythm while in another 4 patients showed paroxysmal Af despite of the treatment with antiarrhythmic agents. In 30 pts with sinus rhythm or paroxysmal Af, right atrial function was restored in all pts while left atrial function was restored in only 19/30(63%). Peak A velocity and A/E ratio were 0.38+/-0.12m/s, 0.74, respectively on tricuspid inflow(TI), and 0.46+/-0.14m/s, 0.40, respectively on mitral inflow(MI ). MI peak A velocity and A/E ratio were significantly lower than the 16 control postoperative pts (0.75<0.29, 0.80 : p+/-0.01). In pts with atrial mechanical function, the duration of Af was significantly shorter than patients without atrial function (1.9+/-2.9 yr vs 7.1+/-3.0 yr : p<0.01), but no significant differences in the LA size and volume. CONCLUSION: Maze operation is effective in restoring sinus rhythm. But restoration of sinus rhythm was not always associated with restoration of atrial mechanical function, and the restored atrial function was incomplete. The duration of Af could be a markker for predicting the restoration of atrial function.
Atrial Fibrillation ; Atrial Function ; Atrial Function, Left ; Atrial Function, Right ; Echocardiography, Doppler ; Humans

BACKGROUND: Beyond its current function as a rescue therapy in acute respiratory distress syndrome (ARDS), extracorporeal membrane oxygenation (ECMO) may be applied in ARDS patients with less severe hypoxemia to facilitate lung protective ventilation. The purpose of this study was to evaluate the efficacy of extended ECMO use in ARDS patients. METHODS: This study reviewed 223 adult patients who had been admitted to the intensive care units of 11 hospitals in Korea and subsequently treated using ECMO. Among them, the 62 who required ECMO for ARDS were analyzed. The patients were divided into two groups according to pre-ECMO arterial blood gas: an extended group (n=14) and a conventional group (n=48). RESULTS: Baseline characteristics were not different between the groups. The median arterial carbon dioxide tension/fraction of inspired oxygen (FiO2) ratio was higher (97 vs. 61, p<0.001) while the median FiO2 was lower (0.8 vs. 1.0, p<0.001) in the extended compared to the conventional group. The 60-day mortality was 21% in the extended group and 54% in the conventional group (p=0.03). Multivariate analysis indicated that the extended use of ECMO was independently associated with reduced 60-day mortality (odds ratio, 0.10; 95% confidence interval, 0.02–0.64; p=0.02). Lower median peak inspiratory pressure and median dynamic driving pressure were observed in the extended group 24 hours after ECMO support. CONCLUSION: Extended indications of ECMO implementation coupled with protective ventilator settings may improve the clinical outcome of patients with ARDS.
Adult ; Anoxia ; Carbon Dioxide ; Extracorporeal Membrane Oxygenation ; Humans ; Intensive Care Units ; Korea ; Lung ; Mortality ; Multicenter Studies as Topic ; Multivariate Analysis ; Oxygen ; Respiration, Artificial ; Respiratory Distress Syndrome, Adult ; Retrospective Studies ; Ventilation ; Ventilators, Mechanical

BACKGROUND: Beyond its current function as a rescue therapy in acute respiratory distress syndrome (ARDS), extracorporeal membrane oxygenation (ECMO) may be applied in ARDS patients with less severe hypoxemia to facilitate lung protective ventilation. The purpose of this study was to evaluate the efficacy of extended ECMO use in ARDS patients. METHODS: This study reviewed 223 adult patients who had been admitted to the intensive care units of 11 hospitals in Korea and subsequently treated using ECMO. Among them, the 62 who required ECMO for ARDS were analyzed. The patients were divided into two groups according to pre-ECMO arterial blood gas: an extended group (n=14) and a conventional group (n=48). RESULTS: Baseline characteristics were not different between the groups. The median arterial carbon dioxide tension/fraction of inspired oxygen (FiO2) ratio was higher (97 vs. 61, p<0.001) while the median FiO2 was lower (0.8 vs. 1.0, p<0.001) in the extended compared to the conventional group. The 60-day mortality was 21% in the extended group and 54% in the conventional group (p=0.03). Multivariate analysis indicated that the extended use of ECMO was independently associated with reduced 60-day mortality (odds ratio, 0.10; 95% confidence interval, 0.02–0.64; p=0.02). Lower median peak inspiratory pressure and median dynamic driving pressure were observed in the extended group 24 hours after ECMO support. CONCLUSION Extended indications of ECMO implementation coupled with protective ventilator settings may improve the clinical outcome of patients with ARDS.

Objectives: Sepsis is a leading global cause of mortality, and predicting its outcomes is vital for improving patient care. This study explored the capabilities of ChatGPT, a state-of-the-art natural language processing model, in predicting in-hospital mortality for sepsis patients. Methods: This study utilized data from the Korean Sepsis Alliance (KSA) database, collected between 2019 and 2021, focusing on adult intensive care unit (ICU) patients and aiming to determine whether ChatGPT could predict all-cause mortality after ICU admission at 7 and 30 days. Structured prompts enabled ChatGPT to engage in in-context learning, with the number of patient examples varying from zero to six. The predictive capabilities of ChatGPT-3.5-turbo and ChatGPT-4 were then compared against a gradient boosting model (GBM) using various performance metrics. Results: From the KSA database, 4,786 patients formed the 7-day mortality prediction dataset, of whom 718 died, and 4,025 patients formed the 30-day dataset, with 1,368 deaths. Age and clinical markers (e.g., Sequential Organ Failure Assessment score and lactic acid levels) showed significant differences between survivors and non-survivors in both datasets. For 7-day mortality predictions, the area under the receiver operating characteristic curve (AUROC) was 0.70–0.83 for GPT-4, 0.51–0.70 for GPT-3.5, and 0.79 for GBM. The AUROC for 30-day mortality was 0.51–0.59 for GPT-4, 0.47–0.57 for GPT-3.5, and 0.76 for GBM. Zero-shot predictions using GPT-4 for mortality from ICU admission to day 30 showed AUROCs from the mid-0.60s to 0.75 for GPT-4 and mainly from 0.47 to 0.63 for GPT-3.5. Conclusions GPT-4 demonstrated potential in predicting short-term in-hospital mortality, although its performance varied across different evaluation metrics.