Risk factors for transmission in a COVID-19 cluster infection in a high school in the Republic of Korea

Objectives@#This study aimed to examine the scale, characteristics, risk factors, and modes of transmission in a coronavirus disease 2019 (COVID-19) outbreak at a high school in Seoul, Republic of Korea. @*Methods@#An epidemiological survey was conducted of 1,118 confirmed cases and closecontacts from a COVID-19 outbreak at an educational facility starting on May 31, 2021. Indepth interviews, online questionnaires, flow evaluations, and CCTV analyses were used todevise infection prevention measures. Behavioral and spatial risk factors were identified, and statistical significance was tested. @*Results@#Among 3rd-year students, there were 33 confirmed COVID-19 cases (9.6%). Students who used a study room in the annex building showed a statistically significant 4.3-foldelevation in their relative risk for infection compared to those who did not use the study room. Moreover, CCTV facial recognition analysis confirmed that 17.8% of 3rd-year students did not wear masks and had the lowest percentage of mask-wearers by grade. The air epidemiological survey conducted in the study room in the annex, which met the 3 criteria for a closed space, confirmed that there was only 10% natural ventilation due to the poor ventilation system. @*Conclusion@#To prevent and manage the spread of COVID-19 in educational facilities, advance measures that consider the size, operation, and resources of each school are crucial. In addition, various survey methodologies should be used in future studies to quickly analyze a wider range of data that can inform an evidence-based quarantine response.

Brain endothelial cell-derived extracellular vesicles with a mitochondria-targeting photosensitizer effectively treat glioblastoma by hijacking the blood‒brain barrier

Glioblastoma (GBM) is the most aggressive malignant brain tumor and has a high mortality rate. Photodynamic therapy (PDT) has emerged as a promising approach for the treatment of malignant brain tumors. However, the use of PDT for the treatment of GBM has been limited by its low blood‒brain barrier (BBB) permeability and lack of cancer-targeting ability. Herein, brain endothelial cell-derived extracellular vesicles (bEVs) were used as a biocompatible nanoplatform to transport photosensitizers into brain tumors across the BBB. To enhance PDT efficacy, the photosensitizer chlorin e6 (Ce6) was linked to mitochondria-targeting triphenylphosphonium (TPP) and entrapped into bEVs. TPP-conjugated Ce6 (TPP-Ce6) selectively accumulated in the mitochondria, which rendered brain tumor cells more susceptible to reactive oxygen species-induced apoptosis under light irradiation. Moreover, the encapsulation of TPP-Ce6 into bEVs markedly improved the aqueous stability and cellular internalization of TPP-Ce6, leading to significantly enhanced PDT efficacy in U87MG GBM cells. An in vivo biodistribution study using orthotopic GBM-xenografted mice showed that bEVs containing TPP-Ce6 [bEV(TPP-Ce6)] substantially accumulated in brain tumors after BBB penetration via transferrin receptor-mediated transcytosis. As such, bEV(TPP-Ce6)-mediated PDT considerably inhibited the growth of GBM without causing adverse systemic toxicity, suggesting that mitochondria are an effective target for photodynamic GBM therapy.

The Impact of Public Transfer Income on Catastrophic Health Expenditures for Households With Disabilities in Korea / 예방의학회지

Objectives@#Previous studies have reported that people with disabilities are more likely to be impoverished and affected by excessive medical costs than people without disabilities. Public transfer income (PTI) reduces financial strain in low-income households. This study examined the impact of PTI on catastrophic health expenditures (CHE), focusing on low-income households and households with Medical Aid beneficiaries that contained people with disabilities. @*Methods@#We constructed a panel dataset by extracting data on registered households with disabilities from the Korea Welfare Panel Study 2012-2019. We then used a generalized estimating equation model to estimate the impacts of PTI on CHE. A subgroup analysis was carried out to assess the moderating effects of family income levels and health insurance types. @*Results@#As PTI increased, the odds ratio (OR) of CHE in households that contained people with disabilities decreased significantly (OR, 0.92; 95% confidence interval [CI], 0.89 to 0.94; p<0.001). In particular, PTI effectively reduced the likelihood of CHE for low-income households (OR, 0.85; 95% CI, 0.81 to 0.89; p<0.001) and those who received medical benefits (OR, 0.78; 95% CI, 0.68 to 0.89; p<0.001). @*Conclusions@#This study highlights the positive effect of PTI on decreasing CHE. Household income and the health insurance type were significant effect modifiers, but economic barriers seemed to persist among low-income households with non-Medical Aid beneficiaries. Federal policies or programs should consider increasing the total amount of PTI targeting low-income households with disabilities that are not covered by the Medical Aid program.

Effects of in-Person, in-Hospital Education for Stroke Patients by an Education-Specialized Nurse

BACKGROUND: We assessed the effects of customized in-hospital, in-person education provided by an education-specialized nurse in ischemic stroke patients. METHODS: All ischemic stroke patients who were hospitalized between April 2015 and December 2015 were included. They were provided with education about stroke by an education-specialized nurse during their hospital stay. The knowledge of stroke warning signs and appropriate responses was examined both before the in-hospital education and 3 months after discharge in 127 patients. RESULTS: The awareness of the following stroke warning signs increased significantly at 3 months after discharge compared to before receiving the education (all p values <0.001): sudden difficulty in speaking or in understanding speech (74.0→93.7%), sudden numbness or weakness (72.4→92.1%), sudden dizziness (71.7→89.8%), sudden severe headache (44.9→82.7%), and sudden visual impairment (38.6→69.3%). The proportion of patients with a good knowledge of stroke warning signs (defined as providing at least five correct answers) increased significantly, from 38.6% to 81.9%. Almost half of them (46.5%) correctly answered that they should call an ambulance first when someone shows stroke symptoms before receiving the education, with this proportion increasing to 68.5% at 3 months after discharge (p<0.001). The proportions of patients who understood the need for prompt treatment of stroke and the golden time window increased from 80.3% to 96.9% and from 66.1% to 86.6%, respectively (both p<0.001). The proportion of patients with knowledge of thrombolytic therapy for stroke also increased significantly after the in-hospital education, from 11.0% to 76.4% (p<0.001). CONCLUSIONS: In-hospital, in-person education was effective at increasing the understanding that patients have of stroke, even at 3 months after discharge. In-hospital education provided by an education-specialized nurse would be an effective intervention for increasing the likelihood of stroke patients reacting appropriately to stroke recurrence.

A Case of Washed Platelet Transfusion in a Patient with History of Recurrent Transfusion Reaction / 대한수혈학회지

Anaphylactic transfusion reaction is caused by deficiency of certain protein(s) in the recipient. We report on the experience of platelet count recovery using washed platelets for transfusion in a patient who developed an anaphylactic transfusion reaction. A 50-year old male diagnosed with angioimmunoblastic T-cell lymphoma was treated with chemotherapy followed by autologous hematopoietic stem cell transplantation. Immediately after starting transfusion of apheresis platelets, he began sweating and complained of visual impairment, chest discomfort, and abdominal pain. Both systolic and diastolic blood pressures and oxygen saturation monitored by pulse oximetry were decreased. Platelet transfusion was discontinued immediately and hydrocortisone was administered, and the symptoms and signs were resolved within two hours. Laboratory test using post-transfusion blood showed no apparent evidence of hemolysis. Platelet washing procedure using normal saline three times was newly set to prevent anaphylactic reaction in the patient. Transfusions of washed platelets were performed 20 times for 60 days, and the patient showed no anaphylactic reaction during this period. He showed no evidence of immunoglobulin A, haptoglobin, C3, or C4 deficiencies. We confirmed that washed platelet transfusion is highly effective for prevention of anaphylactic transfusion reaction.

Characterization of a prenatally diagnosed de novo der(X)t(X;Y)(q27;q11.23) of fetus

A 31-year-old woman, who was pregnant with twins, underwent chorionic villus sampling because of increased nuchal translucency in one of the fetuses. Cytogenetic analysis showed a normal karyotype in the fetus with increased nuchal translucency. However, the other fetus, with normal nuchal translucency, had a derivative X chromosome (der(X)). For further analysis, fluorescence in situ hybridization (FISH) and additional molecular studies including fragile X analysis were performed. FISH analysis confirmed that the Y chromosome was the origin of extra segment of the der(X). The X-chromosome breakpoint was determined to be at Xq27 by FMR1 CGG repeat analysis, and the Y-chromosome breakpoint was determined to be at Yq11.23 by the Y chromosome microdeletion study. To predict the fetal outcome, the X-inactivation pattern was examined, and it revealed non-random X inactivation of the der(X). To the best of our knowledge, the identification of an unbalanced Xq;Yq translocation at prenatal diagnosis has never been reported. This study was performed to identify precise breakpoints and the X-inactivation pattern as well as to provide the parents with appropriate genetic counseling.

Network Computer Management System Development for Blood Transfusion in ABO-Incompatible Stem Cell Transplantation / 대한수혈학회지

BACKGROUND: The majority of patients undergoing stem cell transplantation (SCT) require a blood transfusion until the complete engraftment. Because blood transfusion rules for patients with ABO-incompatible SCT are complicated, we developed an ABO-incompatible transfusion management system (ABO-ITMS) for accurate blood transfusion and improved manageability. METHODS: A committee composed of medical doctors, technicians, and a programmer developed ABO-ITMS during the eight months from July 2013 to February 2014. The program has been linked with other databases, including clinical and laboratory databases and resulted in a new subsystem of the health information system. Server computer's operating system was Window Server 2008, and the database manager program was Oracle 11g. Programming language was ASP.Net (VBScript, C #), and the server and client computer were used to connect to the web server using a web browser. RESULTS: ABO-ITMS was designed to follow three main steps by hematologic oncology clinic, laboratory physician, and blood bank. In the first step, a hematologic-oncology clinic doctor inputs SCT recipients' data and appropriate ABO group for each phase of post-transplantation. Laboratory physician enters the isoagglutinin titer and ABO group at the second step. Finally, blood bank workers enter the results of type, screening, and antibody identification. The patient's SCT information and the previous immunohematologic test results are shown on the screen. CONCLUSION: ABO-ITMS can replace the existing complicated system and workflow. ABO-ITMS will contribute to reducing medical error and improving quality of SCT recipient care.

Effects of Calcium Gluconate, a Water Soluble Calcium Salt on the Collagen-Induced DBA/1J Mice Rheumatoid Arthritis

This study examined the effects of calcium (Ca) gluconate on collagen-induced DBA mouse rheumatoid arthritis (CIA). A single daily dose of 200, 100 or 50 mg/kg Ca gluconate was administered orally to male DBA/1J mice for 40 days after initial collagen immunization. To ascertain the effects administering the collagen booster, CIA-related features (including body weight, poly-arthritis, knee and paw thickness, and paw weight increase) were measured from histopathological changes in the spleen, left popliteal lymph node, third digit and the knee joint regions. CIA-related bone and cartilage damage improved significantly in the Ca gluconate- administered CIA mice. Additionally, myeloperoxidase (MPO) levels in the paw were reduced in Ca gluconate-treated CIA mice compared to CIA control groups. The level of malondialdehyde (MDA), an indicator of oxidative stress, decreased in a dose-dependent manner in the Ca gluconate group. Finally, the production of IL-6 and TNF-alpha, involved in rheumatoid arthritis pathogenesis, were suppressed by treatment with Ca gluconate. Taken together, these results suggest that Ca gluconate is a promising candidate anti-rheumatoid arthritis agent, exerting anti-inflammatory, anti-oxidative and immunomodulatory effects in CIA mice.

Change in characteristics of human vagal sigmoidal baroreflex curve during conscious state and general anesthesia / 대한마취과학회지

BACKGROUND: Volatile anesthetics have been shown to decrease baroreflex. In humans, cardiovagal baroreflex curve is best described to be sigmoidal and analysis of sigmoid model can provide more information, such as threshold (THR), saturation (SAT), maximal gain (Gmax), operating range (OR, difference between THR and SAT), operational point (OP, relative position of resting set point within the OR) in addition to the linear gain. We compared the changes in the sigmoid model of the systolic blood pressure (SBP)-RR interval relation between awake state and general anesthesia. METHODS: Sigmoid curve was obtained using the 'modified Oxford technique' (bolus sodium nitroprusside followed by bolus phenylephrine) to perturb SBP in awake group and 2 vol% sevoflurane anesthesia group. Radial arterial beat-by-beat SBP and raw RR interval data points were plotted and then binned in 2 mmHg SBP increments. Curve fittings were performed using symmetric four-parameter sigmoid model and asymmetric five-parameter sigmoid model. Gmax was calculated from the first derivative of the logistic function. RESULTS: Compared with awake control, general anesthesia caused decreases of linear gain, Gmax and OR. RR interval THR and SBP THR were unaffected, whereas SBP SAT increased and RR interval SAT decreased, resulting from reduced linear gain and curvature parameter. Resting set point fell and OP shifted significantly to THR region. CONCLUSIONS: Sigmoidal baroreflex curve revealed diminished gains, OR and OP during general anesthesia. Moreover, our results demonstrate that the analysis of sigmoid baroreflex arc across the entire baroreflex range provide more unique information beyond that of linear gain.

Effects of magnesium infusion on hemodynamic and autonomic changes in healthy volunteers / 대한마취과학회지

BACKGROUND: Magnesium has been used for treatments and preventions of various situations, such as cardiovascular disease and pre-eclampsia. And it also used for decreasing demands of anesthetics and analgesics during anesthesia. Activity of autonomic nervous system has important roles for homeostasis of cardiovascular system, and its dysfunction affects mortality and morbidity. Because there are few reports about effects of magnesium infusion on autonomic nervous system, we investigated effects of magnesium infusion on hemodynamic and autonomic changes using variable autonomic function tests in healthy volunteers. METHODS: Hemodynamic parameters, heart rate variability, blood pressure variability, and baroreflex sensitivity were evaluated before and after magnesium infusion of 30 mg/kg during 20 min in twenty healthy volunteers. Cold face test, valsalva maneuver were also performed before and after magnesium infusion. RESULTS: Low-frequency components of blood pressure variability decreased after magnesium infusion (P = 0.026). There were no significant differences in blood pressure, heart rate, cardiac output, stroke volume, total peripheral resistance, heart rate variablility and baroreflex sensitivity between before and after magnesium infusion. Increases of diastolic blood pressure during cold face test decreased significantly after magnesium infusion (P = 0.022). In addition, no significant hemodynamic and autonomic changes were found during valsalva maneuver. CONCLUSIONS: Central sympathetic vasomotor tone decreased after magnesium infusion of 30 mg/kg during 20 min in healthy volunteers. However, it had no effects on parasympathetic system and baroreflex sensitivity.

Airway Management of Patient with Ankylosing Spondylitis and Mental Retardation : A case report

Almost all anesthesiologists are encounter a difficult airway occasionally, which is probably the most important cause of anesthesia related morbidity and mortality. The Intubating Laryngeal Mask Airway (ILMA) is a modified laryngeal mask airway with the capability for guided tracheal intubation while maintaining ventilation. We report the successful use of this device in patient with ankylosing spondylitis, mental retardation and hearing disturbance. This case suggests that ILMA is a safe and useful method for airway management in anesthetic care of uncooperative patients.

Assessment of Fluid Space after Infusion of Hartmann's Solution and Hydroxethyl Starch Solutions during General Anesthesia / 대한마취과학회지

BACKGROUND: Distribution and elimination of crystalloid or colloid solutions during inhalational anesthesia have not been adequately investigated. Hemoglobin dilution and fluid kinetic model have been shown to reveal the distribution and elimination of various kinds of fluids. Therefore, we assessed fluid space changes after Hartmann's solution or hydroxyethyl starch solution (HES) infusion during desflurane anesthesia. METHODS: We infused 20 ml/kg of Hartmann's solution, 8.5 ml/kg of Hextend(R) and 8.5 ml/kg of Voluven(R) during 20 min, after anesthesia induction and before surgical incision, and measured the hemoglobin changes. We used mass balance equations and a fluid kinetic model to evaluate the changes of fluid space. In the fluid kinetic model, we used one volume model, which allows estimation of the size of the body fluid space expanded by the fluid (V) and the elimination rate constant (kr). RESULTS: The expanded plasma volume of three different fluids, calculated using mass balance equations, showed a similar degree of expansion during infusion, however, after finishing infusion, the dilution effect of Hartmann's solution decreased rapidly and lasted less than HES. Fluid kinetic model shows the mean size of V of 12.3 +/-5.9 L for Hartmann' solution, 5.2 +/- 1.6 L for Hextend, and 4.5 +/- 1.6 L for Voluven. Corresponding kr values were 263.0 +/- 161.8, 36.5 +/- 31.8, and 34.1 +/- 21.3 ml/min, respectively. CONCLUSIONS: The distribution volume of intravenous fluids analyzed by kinetic model showed that crystalloid fluid has a similar volume distribution compared to extracellular fluid and HES distributed to a volume larger than blood volume. Analysis and simulation of plasma volume expansion using this model provide a helpful tool for anesthesiologists planning fluid therapy.

Pseudoisodicentric X chromosome in a female with primary amenorrhea

A 24-year-old female with primary amenorrhea was referred for a chromosome study. The karyotype of the patient was 46,X,der(X) under initial GTG-banding analysis. Fluorescence in situ hybridization (FISH) analysis with an LSI Kallmann (KAL) region probe [probes for Xp22.3(KAL) and CEP(X) for control] was carried out. The abnormal chromosome was KAL- and CEP(X)x2. In addition, interphase FISH analysis revealed the patient to be mosaic for two different cell lines: 90% of cells had three signals and 10% of the cells had only one signal for CEP(X). Based on these results, the karyotype of the patient was 45,X/46,X,psu idic(X)(p22.1), which is partial trisomy for Xqter-->Xp22.1 and partial monosomy for Xpter-->Xp22.1. This karyotype was considered a variant of Turner syndrome. In summary, Idic(X) and low-level mosaicism was successfully characterized by FISH analysis with a CEP(X) probe.

Intravenous Patient-controlled Analgesia using Remifentanil after Cardiac Surgery / 대한마취과학회지

BACKGOUND: For rapid onset and predictable elimination half life, remifentanil may be suitable for patients undergoing cardiac surgery with unstable vital sign and decreased metabolism. We evaluated the efficacy, safety and proper dosage of intravenous patient-controlled analgesia (IV PCA) using remifentanil in patients undergoing cardiac surgery. METHODS: Forty-nine patients scheduled for cardiac surgery with sternotomy were randomly allocated to three groups. Group F had IV PCA using fentanyl with basal rate of 0.3microgram/kg/h, bolus of 0.5microgram/kg and lockout time of 15 min. Group L had remifentanil IV PCA with basal rate of 4microgram/kg/h, and group S with basal rate of 1microgram/kg/h. Both of group L and group S had setting of bolus of 0.5microgram/kg and lockout time of 5 min. In 12, 24 and 36 hours after surgery, vital sign, arterial blood gas analysis, visual analog pain scale (VAS), sedation score, and incidences of side effects were evaluated. RESULTS: The VAS score of group L was significantly low until 24 hours after surgery compared with other groups (P < 0.001). In group L, sedation score and PaCO2 in 12 hours after surgery were significantly high compared with other groups (P < 0.05), but no treatments were needed. CONCLUSIONS: Remifentanil IV PCA with basal rate of 4microgram/kg/h showed lower VAS score compared with small dosage of remifentanil and fentanyl with basal rate of 0.3microgram/kg/h. In the safety and proper dosage, further evaluations were needed.

The Influence of Sevoflurane Anesthesia on Various Kinds of Spontaneous Baroreflex Sensitivities / 대한마취과학회지

BACKGROUND: In contrast to classic drug injection method, various types of noninvasive spontaneous baroreflex sensitivity (SBRS) methods have been developed using the computer analysis of the spontaneous fluctuation of heart rate and arterial blood pressure for baroreflex evaluation. In this study, we evaluated the effects of sevoflurane anesthesia on SBRS by comparing various SBRS estimates and their correlations before and after sevoflurane anesthesia. METHODS: Radial arterial pressure and electrocardiography were recorded in 50 patients before and after sevoflurane anesthesia. We derived six SBRS indices from the methods including sequence, alpha-index, transfer function analysis and impulse response function. The sequence method measured an average of baroreflex sequences. The alpha-index used the average of the square roots of the ratios between the RRI and SBP spectral power. The transfer function index used RRI and SBP cross-spectral magnitude for this index. The impulse response function method employed an inverse Fourier transform. RESULTS: All SBRS and accompanying correlations were reduced after sevoflurane anesthesia. Low (44%) and high (4%) frequency transfer function gain and sequence SBRS (4%) failed to be computed out of some patients after sevoflurane anesthesia due to poor coherence and absence of a valid sequence. CONCLUSIONS: Sevoflurane anesthesia caused marked depression of SBRS and weakened their correlations. Therefore, it is necessary to understand the characteristics of each SBRS method for selecting an appropriate method during anesthesia.

The Effect of Sevoflurane Anesthesia on the Phase Relationship between Systolic Blood Pressure and Heart Rate / 대한마취과학회지

BACKGROUND: The phase relationship indicates the time delay between the input signal (systolic blood pressure, SBP) and output signal (R-R interval, RRI). In contrast to the awake state, little is known about the effects of general anesthesia on the phase shift. In the present study, we tested the hypothesis that sevoflurane anesthesia causes a phase change between the two signals. METHODS: We assessed changes in phase, coherence, and baroreflex sensitivity between SBP and RRI by the use of transfer function analysis in 50 ASA 1 patients during the awake state and during end-tidal 2% sevoflurane-50% N2O anesthesia. RESULTS: SBP and RRI decreased significantly during sevoflurane anesthesia (P < 0.001). The phase in the low frequency (LF) region remained unchanged, but the phase in the high frequency (HF) region changed significantly from -29.52 +/- 50.70 to 27.28 +/- 80.22 degrees during sevoflurane anesthesia (P < 0.001). Coherence and baroreflex sensitivity between the two signals in the LF and HF regions decreased significantly during sevoflurane anesthesia (P < 0.001, respectively). CONCLUSIONS: We found that in the HF region and not in the LF region, sevoflurane anesthesia provokes the shift of the SBP-RRI phase relationship, suggesting that this change is inconsistent with a vagally mediated response.

Assessment of the Mechanism of Arterial Blood Pressure Change during Sevoflurane Induction: Beat-to-Beat Analysis of Hemodynamic Variables Using a Modelflow Method / 대한마취과학회지

BACKGROUND: A modelflow method provides beat-to-beat analysis of cardiovascular variables based on arterial pulse pressure analysis. In this study, we assessed the mechanism of arterial blood pressure (ABP) change during sevoflurane induction by the analysis of beat-to-beat hemodynamic changes using a modelflow method. METHODS: Beat-to-beat ABP was measured during a stable conscious state (baseline) and vital capacity induction with sevoflurane 6 vol% and oxygen 8 L/min in 18 healthy living liver transplant donors. Alterations of beat-to-beat systolic ABP, mean ABP, diastolic ABP, heart rate (HR), stroke volume (SV), cardiac output (CO), and total peripheral resistance (TPR) by sevoflurane induction were estimated noninvasively using a modelflow method simulating aortic input impedance from an ABP waveform. RESULTS: After sevoflurane induction, ABP, SV, CO, and TPR decreased significantly (all P < 0.05), but HR did not change significantly. After tracheal intubation, ABP, CO, and TPR did not change significantly compared with baseline, but HR increased and SV decreased significantly (both P < 0.05). CONCLUSIONS: Using a modelflow beat-to-beat analysis of cardiovascular variables, we found that ABP did not change significantly compared to baseline after tracheal intubation during sevoflurane induction, indicating the counteraction of increased HR and decreased SV, and that the reduction of SV by tracheal intubation suggests the suppression by increased HR and TPR compared with that after sevoflurane induction.

Influence of Anesthesia Induction with Ketamine on Baroreflex Control of Heart Rate / 대한마취과학회지

BACKGROUND: It is reported that ketamine increases central sympathetic activity as well as catecholamine reuptake inhibition. However, little has been known about baroreflex control of heart rate in ketamine anesthetized humans. Thus, the aim of this study was to analyze the effect of ketamine on spontaneous baroreflex sensitivity (BRS) during ketamine induction of anesthesia. METHODS: Beat-by-beat arterial blood pressure and electrocardiogram at 5 min before and 10 min after ketamine administration (2 mg/kg) were recorded in twenty healthy living liver transplant donors. Spontaneous BRS was assessed by sequence method and transfer function analysis method. RESULTS: Spontaneous BRS assessed by sequence method, BRSsequence, decreased from 13.7 +/- 6.3 to 7.8 +/- 4.5 ms/mmHg (P < 0.001). Spontaneous BRS assessed by low frequency transfer function method decreased from 10.9 +/- 5.4 to 7.0 +/- 4.1 ms/mmHg and by high frequency transfer function method from 14.8 +/- 9.2 to 8.7 +/- 8.8 ms/mmHg, respectively (P < 0.05). CONCLUSIONS: The spontaneous BRS was decreased during ketamine induction of general anesthesia. These results suggest that anesthesia induction with ketamine impairs baroreflex control of heart rate, which may provoke hemodynamic instability.

Assessment of Cardiovascular Autonomic Function in Patients with Liver Cirrhosis Using Heart Rate Variability, Blood Pressure Variability and Baroreflex Sensitivity / 대한마취과학회지

BACKGROUND: Liver cirrhosis is associated with several hemodynamic abnormalities, including an impairment of autonomic nervous system reflexes, but very few have compared the disease severity with cardiovascular autonomic dysfunction assessed by spectral analysis of blood pressure and electrocardiogram. The aim of this study was to investigate the relationship between Child-Turcotte-Pugh (CTP) score and autonomic indices in patients with liver cirrhosis using the heart rate variability (HRV), blood pressure variability (BPV) and baroreflex sensitivity (BRS). METHODS: Fifty patients scheduled for liver transplantation recipients under general anesthesia were enrolled in the study. Beat-to-beat blood pressure and RR interval were measured for five minutes before anesthesia induction. HRV and BPV were estimated by power spectral analysis of RR interval and systolic blood pressure. BRS was estimated by both the sequence method (Sequence BRS) and high frequency (HF) gain of transfer function analysis (HF BRS). RESULTS: Significant inverse correlations between CTP score and Sequence BRS (r = -0.61), HF BRS (r = -0.59), low frequency (LF) and HF power of HRV (r = -0.57, r = -0.46), LF power of BPV (r = -0.37) were found. However, no significant correlations were observed between CTP score and LF/HF ratio of HRV (r = -0.02) and HF power of BPV (r = 0.27). CONCLUSIONS: These results showed that autonomic dysfunction assessed by spectral analysis was associated with increasing severity of liver cirrhosis. Further study will be needed to clarify relationship between our findings and hemodynamic fluctuations during anesthesia for liver transplantation.

Airway Management of a Patient with Esophago-tracheal Perforation by Endotracheal Tube: A case report / 대한마취과학회지

Although uncommon and rarely reported, tracheo-esophageal perforation during traumatic intubation is life threatening and associated with a high mortality rate. It may result in severe airway complications such as a pneumothorax, pneumomediastium, pneumonia, and mediastinitis. The mortality rate of esophageal perforation has been reported to range from 6 to 34%, and up to 56% if the diagnosis is delayed by more than 12 hours after the event. In our case, the patient had been intubated for 3 weeks with an esophago-tracheal perforation. The perforation was not found by the physician because he had no signs of esophageal perforation, the tip of endotracheal tube was well in the trachea and balloon of the tube was sufficient to prevent air leakage. After the failure of extubation for three times, the diagnosis was carried out by gastrofibroscopy, bronchoscopy and chest 3-dimensional computed tomography. His tracheal and esophageal walls were injured with severe inflammation. Therefore, primary repair could not be done and only a tracheostomy was performed.