• Journal of Microbiology and Biotechnology
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• v.13 no.5
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• pp.717-724
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• 2003

A newly isolated Citrobacter sp. Y19 catalyzes the CO-dependent $H_2$ production (biological water-gas shift reaction) by the actions of CO dehydrogenase (CODH) and hydrogenase. Y 19 requires $O_2$ for fast growth, but its $H_2$ production activity is significantly inhibited by $O_2$. In the present study, the effect of $O_2$ on the activities of CODH ard hydrogenase was investigated quantitatively in both whole cells and broken cells, based on CO-dependent or methyl viologen (MV)-dependent $H_2$ production in addition to CO-dependent MV reduction. In crude cell extracts, CODH activity was mostly found in the soluble fraction. Inactivation of CODH and hydrogenase activities by $O_2$ followed the first-order decay kinetics, and the dependence of the rate constants on $O_2$ partial pressure could be expressed by the Michaelis-Menten equation. In whole cells, the maximum deactivation rate constants ($k_{d,max}$ of hydrogenase and CODH were quite similar: $0.07{\pm}0.03 min^{-1}\;and\;0.10{\pm}0.04 min^{-1}$, respectively. However, the first-order rate constant ($k_{d,max}/K_s$) of CODH ($0.25\;min^{-1}\;atm^{-1}$) at low $O_2$ partial pressures was about 3-fold higher than that of the hydrogenase, since the half-saturation constant ($K_s$) of CODH was about half of that of hydrogenase. In broken cells, both enzymes became significantly more sensitive to $O_2$ compared to the unbroken cells, while $k_{d,max}/K_s$ increased 37-fold for hydrogenase and 6.7-fold for CODH. When whole cells were incubated under anaerobic conditions after being exposed to air for 1 h, hydrogenase activity was recovered more than 90% in 2 h suggesting that the deactivation of hydrogenase by $O_2$ was reversible. On the contrary, CODH activity was not recovered once deactivated by $O_2$ and the only way to recover the activity was to synthesize new CODH. This study indicates that $O_2$ sensitivity of $H_2$ production activity of Citrobacter sp. Y19 is an important drawback as in other $H_2-producing$ bactria.

• Journal of Korean Academy of Nursing
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• v.53 no.4
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• pp.468-479
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• 2023

Purpose: This study aimed to evaluate the use of the respiratory rate oxygenation (ROX) index, ROX-heart rate (ROX-HR) index, and saturation of percutaneous oxygen/fraction of inspired oxygen ratio (SF ratio) to predict weaning from high-flow nasal cannula (HFNC) in patients with respiratory distress in a pediatric intensive care unit. Methods: A total of 107 children admitted to the pediatric intensive care unit were enrolled in the study between January 1, 2017, and December 31, 2021. Data on clinical and personal information, ROX index, ROX-HR index, and SF ratio were collected from nursing records. The data were analyzed using an independent t-test, χ² test, Mann-Whitney U test, and area under the curve (AUC). Results: Seventy-five (70.1%) patients were successfully weaned from HFNC, while 32 (29.9%) failed. Considering specificity and sensitivity, the optimal cut off points for predicting treatment success and failure of HFNC oxygen therapy were 6.88 and 10.16 (ROX index), 5.23 and 8.61 (ROX-HR index), and 198.75 and 353.15 (SF ratio), respectively. The measurement of time showed that the most significant AUC was 1 hour before HFNC interruption. Conclusion: The ROX index, ROX-HR index, and SF ratio appear to be promising tools for the early prediction of treatment success or failure in patients initiated on HFNC for acute hypoxemic respiratory failure. Nurses caring for critically ill pediatric patients should closely observe and periodically check their breathing patterns. It is important to continuously monitor three indexes to ensure that ventilation assistance therapy is started at the right time.

• Journal of Korean Academy of Fundamentals of Nursing
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• v.17 no.1
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• pp.45-54
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• 2010

Purpose: The purpose of this study was to develop and test an explanatory model of dyspnea in patients with chronic lung disease (CLD). Methods: Participants were 181 patients with CLD, recruited from the outpatient pulmonary clinic of one university hospital in Korea. Data were collected using questionnaires, as well as measurement of 6-minute walking distance (6MWD), oxygen saturation ($SpO_2$), FEV1% predicted, and Body Mass Index (BMI). Results: The results indicated a good fit between the proposed dyspnea model and the collected data [$x^2$=91.27, p= .13, $x^2$/d.f.=1.17, Normal Fit Index= .934]. Oxygenation ($SpO_2$, = -.530), self-efficacy (= -.429), anxiety (= .253), depression (= .224), exercise endurance (6MWD, = -.211), and pulmonary function (FEV1% predicted, = -.178) had a direct effect on dyspnea (all p< .05) and these variables explained 74% of variance in dyspnea. BMI, smoking history, and social support had an indirect effect on dyspnea. Conclusion: The findings of this study suggest that comprehensive nursing interventions should focus on recovery of respiratory health and improvement of emotions, exercise ability, and nutritional status. From this perspective, pulmonary rehabilitation would be an effective strategy for managing dyspnea in patients with CLD.

• Journal of Dental Anesthesia and Pain Medicine
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• v.21 no.2
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• pp.119-128
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• 2021

Background: This study assessed anticipatory dental anxiety levels among 8- to 12-year-old children based on subjective and physiological measures and their correlation. The variations in anxiety based on sex, age, temperament, and academic performance were evaluated. Methods: An observational study was conducted in 60 children recruited from the waiting room over a 6-month period. The operator recorded subjective anxiety in the children using a novel visual facial anxiety scale. The operator also noted the demographic details and child's temperament using the nine dimensions of the Thomas and Chess criteria, and graded children as "easy," "slow to warm-up," and "difficult." The academic performance of the children was graded (parental ratings) on a five-point Likert scale. Physiological variables (heartrate [HR], oxygen saturation[SpO2], and blood pressure [BP]) were recorded by another evaluator. The correlation between anxiety levels and physiological variables was also assessed. The effects of age, sex, temperament, and academic performance on anxiety were evaluated. Results: The study included 60 children aged 8-12 years, including 36 boys and 24 girls. Seventy percent of children had mild to moderate levels of pre-extraction anxiety, while 30% of children demonstrated high anxiety. A significant positive correlation was noted between anxiety levels and HR (rs = 0.477, P < 0.001⁎) and systolic BP (rs = 0.294, P < 0.05), while a significant but inverse correlation was observed with SpO2 (rs = -0.40, P < 0.05). Anxiety did not influence diastolic BP. Children with difficult temperament and poor academic performance had significantly higher anxiety. Conclusion: A high percentage (70%) of children aged 8-12 years had mild to moderate anxiety prior to the extraction procedure. Increased HR, systolic BP, and reduced SpO2 were significantly associated with high levels of anticipatory dental anxiety. Pre-extraction anxiety was significantly related to the temperament and scholastic performance.

• Journal of Korean Clinical Nursing Research
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• v.14 no.3
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• pp.73-85
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• 2008

Purpose: To examine effects of application of bronchodilators after endotracheal suction on peak air way pressure (PAP), lung compliance (Cdyn), oxygen saturation ($SpO_2$), heart rate (HR), blood pressure (BP), and respiration rate (RR) in cardiac surgery patients. Method: Data were collected from October 2007 to March 2008. Participants were patients who were treated with bronchodilators through mechanical ventilators in the SICU. At each suctioning, bronchodilators were applied immediately, and at 5, 10, and 15 minutes after suctioning. Besides PAP, Cdyn, $SpO_2$, HR, BP, RR, data on the frequency of side effects were also collected at 15, 30, 60 minutes after nebulization. Data were analyzed using the SAS program. Results: For application of bronchodilator right after suctioning and after, 5, 10 and 15 minutes, PAP and Cdyn did not show any significant differences although PAP was persistently decreased for 15 to 30 minutes and Cdyn increased at 15 minutes and decreased gradually after nebulization. Besides $SpO_2$, HR, BP, and RR, frequency of side effects did not show any significant difference. Conclusion: Bronchodilators can be applied at any time. However, the positive effects of bronchodilation right after suctioning on PAP and Cdyn, as also shown in previous reports, indicate it is a more efficient clinical process to maintain an adequate airway.

• Tuberculosis and Respiratory Diseases
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• v.82 no.1
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• pp.81-85
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• 2019

Background: Bronchoscopy is a useful diagnostic and therapeutic tool. However, the clinical use of high-flow nasal cannula (HFNC) in adults with acute respiratory failure for diagnostic and invasive procedures has not been well evaluated. We present our experiences of well-tolerated diagnostic bronchoscopy as well as cases of improved saturation in hypoxaemic patients after a therapeutic bronchoscopic procedure. Methods: We retrospectively reviewed data of hypoxaemic patients who had undergone bronchoscopy for diagnostic or therapeutic purposes from October 2015 to February 2017. Results: Ten patients (44-75 years of age) were enrolled. The clinical purposes of bronchoscopy were for diagnosis in seven patients and for intervention in three patients. For the diagnoses, we performed bronchoalveolar lavage in six patients. One patient underwent endobronchial ultrasonography with transbronchial needle aspiration of a lymph node to investigate tumour involvement. Patients who underwent bronchoscopy for therapeutic interventions had endobronchial mass or blood clot removal with cryotherapy for bleeding control. The mean saturation ($SpO_2$) of pre-bronchoscopy in room air was 84.1%. The lowest and highest mean saturation with HFNC during the procedure was 95% and 99.4, respectively. The mean saturation in room air post-bronchoscopy was 87.4%, which was 3.3% higher than the mean room air $SpO_2$ pre-bronchoscopy. Seven patients with diagnostic bronchoscopy had no hypoxic event. Three patients with interventional bronchoscopy showed improvement in saturation after the procedure. Bronchoscopy was well tolerated in all 10 cases. Conclusion: This study suggests that the use of HFNC in hypoxaemic patients during diagnostic and therapeutic bronchoscopy procedures has clinical effectiveness.

• Journal of Biomedical Engineering Research
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• v.22 no.4
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• pp.377-383
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• 2001

In this paper, we present an intensive patient monitoring service through the Internet, which enables medical doctors to watch their patients in a remote site, to monitor their vital signs and to give them some advices for first-aid treatment. The service consists of three service objects: Monitoring Information Service(MIS), Vital Sign Monitoring Service(VSMS) and Multimedia Consulting (MCS). Through the MIS, medical doctors can get information about the patients currently under monitoring, including their names, ages, genders, symptoms, current main complaints and current locations. The VSMS enables medical doctors to monitor in real-time patients' vital signs such as electrocardiogram (ECG), respiration, temperature, blood oxygen saturation (SpO$_{2}$), invasive blood pressure (IBP), and non-invasive blood pressure (NIBP). It also generates alarms when the patients are likely to be in a critical situation. The MCS provides a real-time multimedia desktop conferencing facility for watching patients and instructing attendants to administer some first-aid treatment. We carried out some experiments according to two different scenarios. The intensive patient monitoring service was functioning well in a 100Base-T Ethernet LAN environment.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.55 no.3
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• pp.138-141
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• 2006

Blood flow is one of vital signals related to human physiological information. Photoplethysmograph (PPG) has been used to measure indirectly heart rate, blood oxygen saturation ($SpO_2$), and so on. Because PPG signal is weak and sensitive to motion artifacts, it is very important to continuously obtain stable PPG signal during free movement. In this study, we applied the scaled Fourier linear combiner (SFLC) using both the adaptive filter and FLC to remove effectively the motion artifacts as well as background noise in the real time without additional signal correlated with motion from a accelerometer. The proposed method would be useful to reduce the movement and background noise which are not synchronized with heart rate.

• Journal of Dental Anesthesia and Pain Medicine
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• v.20 no.6
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• pp.397-402
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• 2020

Background: Inferior alveolar nerve block (IANB) is the most common, painful, and anxiety-provoking procedure involving needle insertion for anesthetic solution deposition. DentalVibeⓇ (DV) delivers vibration at a sustained frequency as a counter-stimulation to the site of injection, thereby alleviating pain. The aim of this study was to evaluate and compare the effectiveness of DV and lignocaine hydrochloride 2% gel (Lox 2% jelly) in pain reduction during IANB in children. Methods: A split-mouth randomized clinical trial was designed with a sample of 60 children (age, 6 to 12 years) requiring bilateral IANB for various dental procedures; DV was used while administering IANB and Lox 2% jelly was used as the topical anesthetic before administering IANB at subsequent appointments. During both appointments, pain perception was measured using the sound, eye, motor (SEM) scale and Wong-Baker faces pain rating scale (WBFPRS); oxygen saturation (SpO2) and pulse rate were measured using a pulse oximeter before, during, and after the IANB procedure. The obtained values were tabulated and subjected to statistical analysis. Wilcoxon test was used for intergroup comparison, and Friedman test, for intragroup comparison of measured variables at different treatment phases. Results: The medians and interquartile ranges of the WBFPRS scores recorded during the IANB procedure for DV and Lox 2% jelly were 2 (2-4) and 2 (0-2), respectively (P < 0.05). The SEM scale scores, mean SpO2, and pulse rate did not show any significant differences during the IANB procedure between both treatments. Conclusion: Both DV and Lox 2% jelly were found to be effective in pain reduction during IANB in children.

• The Journal of Internal Korean Medicine
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• v.38 no.5
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• pp.789-796
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• 2017

Objectives: We examined the effects of Sinbi-tang on a patient with pontine hemorrhage and respiratory disturbance. Methods: A patient diagnosed with pontine hemorrhage and respiratory disturbance was treated with herbal medicine and acupuncture. We checked the peripheral oxygen saturation ($SpO^2$) by oximetry three times a day, and obtained an average value. We evaluated the improvement of symptoms by changes in the average applied $O^2$ and average $SpO^2$. Results: After taking Sinbi-tang and treatment with acupuncture therapy, the patient showed improvement in respiratory disturbance. Applied $O^2$ was gradually decreased from 4 L/min to 0 L/min and $SpO^2$ was stabilized. Conclusions: Korean medicine may provide effective treatment for respiratory disturbance in patients with pontine hemorrhage, but further study is needed.