• Journal of Dental Anesthesia and Pain Medicine
• /
• v.20 no.2
• /
• pp.73-81
• /
• 2020

Background: The international organization for standardization (ISO) 80601-2-61 dictates that the accuracy of a pulse oximeter should be assessed by a controlled desaturation study. We aimed to characterize the relationship between the fraction of inspired oxygen (FiO₂) and peripheral oxygen saturation (SpO₂) using a turnover model by retrospectively analyzing the data obtained from previous controlled desaturation studies. Materials and Methods: Each volunteer was placed in a semi-Fowler's position and connected to a breathing circuit to administer the hypoxic gas mixture containing medical air, oxygen, nitrogen, and carbon dioxide. Volunteers were exposed to various levels of induced hypoxia over 70-100% arterial oxygen saturation (SaO₂). The study period consisted of two rounds of hypoxia and the volunteers were maintained in room air between each round. FiO₂ and SpO₂ were recorded continuously during the study period. A population pharmacodynamic analysis was performed with the NONMEM VII level 4 (ICON Development Solutions, Ellicott City, MD, USA). Results: In total, 2899 SpO₂ data points obtained from 20 volunteers were used to determine the pharmacodynamic characteristics. The pharmacodynamic parameters were as follows: k_out = 0.942 1/min, Imax = 0.802, IC₅₀ = 85.3%, γ = 27.3. Conclusion: The changes in SpO₂ due to decreases in FiO₂ well explained by the turnover model with inhibitory function as a sigmoidal model.

• The Journal of Korea Assosiation for Disability and Oral Health
• /
• v.4 no.1
• /
• pp.21-25
• /
• 2008

A 33-years-old female pateint with cerebral palsy showing spastic quardriplegia and severe mental retardation was scheduled for dental implant restorations. Before implant surgery we had to take implant CT. But, because of her involuntary motion and communication difficulty, sedation was needed in order to take CT. After 8 hour NPO, propofol infusion sedation with TCI (target controlled infusion) system was administered. The propofol blood concentration of the patient was maintained 2-3 ${\mu}$/ml to keep deep sedation to prevent uncontolled movement. During sedation, we monitored ECG, pulse oximetry, blood pressure, capnometry for patient safety. Oxygen was administered via nasal prong for preventing hypoxemia and to keep airway during sedation some bands were applied to lift mandible. Total duration was 20 minutes for taking CT, and she was discharged from hospital after 30 minute rest without complication.

• Journal of The Korean Dental Society of Anesthesiology
• /
• v.12 no.2
• /
• pp.105-109
• /
• 2012

The gag reflex is a physiological reaction, but, an exaggerated gag reflex can be a severe limitation not only to treat dental caries but also to do oral exam. Procedures such as surface anesthesia of the palate and pharyngeral area, sedation, or general anesthesia can be options as behavioral management. But, there are no golden rule for the sever gag reflex patients. We present a case report of propofol intravenous sedation using TCI pump for simple dental treatment. A 44-year-old man, who had past history of general anesthesia for dental treatment because of severe gag reflex, was scheduled intravenous sedation for simple dental treatment. After 8 hour fasting he entered the clinic for persons with disabilities. We explained about intravenous deep sedation and got informed consent. First, we kept intravenous catheter (22G) in the arm and started monitoring ECG, non-invasive blood pressure, pulse oximetry and end-tidal $CO_2$ through nasal cannula. We started propofol infusion with TCI pump at the target concentration of 3 mcg/ml. The patient became sedated, but he showed involuntary movement during dental treatment, so we increased the target concentration to 4 mcg/ml. We finished the dental treatment without complications during 30 min. And after 40 min recovery room stay he was discharged without any complications.

• Journal of Trauma and Injury
• /
• v.31 no.2
• /
• pp.103-106
• /
• 2018

Fat embolism refers to the presence of fat droplets within the peripheral and lung microcirculation with or without clinical sequelae. However, early diagnosis of fat embolism is very difficult because the embolism usually does not show at the computed tomography as a large fat complex within vessels. Forty-eight-year-old male with pedestrian traffic accident ransferred from a local hospital by helicopter to the regional trauma center by two flight surgeons on board. At the rendezvous point, he had suffered with dyspnea without any airway obstruction sign with 90% of oxygen saturation from pulse oximetry with giving 15 L of oxygen by a reserve bag mask. The patient was intubated at the rendezvous point. The secondary survey of the patient revealed multiple pelvic bone fracture with sacrum fracture, right femur shaft fracture and right tibia head fracture. Abdominal computed tomography was performed in 191 minutes after the injury and fat embolism with Hounsfield unit of -86 in his right common iliac vein was identified. Here is a very rare case that mass of fat embolism was shown within common iliac vein detected in computed tomography. Early detection of the fat embolus and early stabilization of the fractures are essential to the prevention of sequelae such as cerebral fat embolism.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.14 no.5
• /
• pp.1303-1310
• /
• 2010

Recently, researches related with automative mechanism have been widely studied to increase the driver's safety by continuously monitoring the driver's health condition to prevent driver's drowsiness. This paper describes the design of wearable chest belt for ECG and reflectance pulse oximetry for SpO2 sensors based on wireless sensor network to monitor the driver's healthcare status. ECG, SpO2 and heart rate signals can be transmitted via wireless sensor node to base station connected to the server. Intelligent monitoring system is designed at the server to analyze the SpO2 and ECG signals. HRV (Heart Rate Variability) signals can be obtained by processing the ECG and PPG signals. HRV signals are further analyzed based on time and frequency domain to determine the driver's drowsiness status.

• Journal of Yeungnam Medical Science
• /
• v.35 no.1
• /
• pp.84-88
• /
• 2018

A 33-year-old woman visited the emergency department presenting with fever and dyspnea. She was pregnant with gestational age of 31 weeks and 6 days. She had dysuria for 7 days, and fever and dyspnea for 1 day. The vital signs were as follows: blood pressure 110/70 mmHg, heart rate 118 beats/minute, respiratory rate 28/minute, body temperature $38.7^{\circ}C$, and oxygen saturation by pulse oximetry 84% during inhalation of 5 liters of oxygen by nasal prongs. Crackles were heard over both lung fields. There were no signs of uterine contractions. Chest X-ray and chest computed tomography scan showed multiple consolidations and air bronchograms in both lungs. According to urinalysis, there was pyuria and microscopic hematuria. She was diagnosed with community-acquired pneumonia and urinary tract infection (UTI) that progressed to severe sepsis and acute respiratory failure. We found extended-spectrum beta-lactamase producing Escherichia coli in the blood culture and methicillin-resistant Staphylococcus aureus in the sputum culture. The patient was transferred to the intensive care unit with administration of antibiotics and supplementation of high-flow oxygen. On hospital day 2, hypoxemia was aggravated. She underwent endotracheal intubation and mechanical ventilation. After 3 hours, fetal distress was suspected. Under 100% fraction of inspired oxygen, her oxygen partial pressure was 87 mmHg in the arterial blood. She developed acute kidney injury and thrombocytopenia. We diagnosed her with multi-organ failure due to severe sepsis. After an emergent cesarean section, pneumonia, UTI, and other organ failures gradually recovered. The patient and baby were discharged soon thereafter.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2009.10a
• /
• pp.545-548
• /
• 2009

Recently, researches related to automative mechanism have been widely studied to increase the driver's safety by continuously monitoring the driver's health condition to prevent driver's drowsiness. This paper describes the design of wearable chest belt for ECG and reflectance pulse oximetry for $SpO_2$ sensors based on wireless sensor network to monitor the driver's healthcare status. ECG, $SpO_2$ and heart rate signals can be transmitted via wireless sensor node to base station connected to the server. Intelligent monitoring system is designed at the server to analyze the $SpO_2$ and ECG signals. HRV(Heart Rate Variability) signals can be obtained by processing the ECG and PPG signals. HRV signals are further analyzed based on time and frequency domain to determine the driver's drowsiness status.

• Clinical Endoscopy
• /
• v.56 no.2
• /
• pp.188-193
• /
• 2023

Background/Aims: Data on the incidence of adverse respiratory events during recovery from gastrointestinal endoscopy are limited. The aim of this study was to investigate the incidence of these complications. Methods: In this retrospective cohort study, data were obtained from the electronic records of 657 consecutive patients, who underwent gastroenterological procedures under sedation. Results: Pulse oximetry oxygen saturation (SpO₂) <90% for <60 seconds occurred in 82 patients (12.5%), and in 11 patients (1.7%), SpO₂ of <90% for >60 seconds occurred in 79 patients (12.0%) and in 14 patients (2.1%), and SpO₂ <75% occurred in four patients (0.6%) and in no patients during the procedure and recovery period, respectively. No major complications were noted. The occurrence of desaturation during recovery was correlated with desaturation during the procedure (p<0.001). Higher American Society of Anesthesiologists score (odds ratio [OR], 1.867; 95% confidence interval [CI], 1.008-3.458), ischemic heart disease (OR, 1.815; 95% CI, 0.649-5.080), hypertension (OR, 1.289; 95% CI, 0.472-3.516), and diabetes mellitus (OR, 2.406; 95% CI, 0.950-6.095) increased the occurrence of desaturation during recovery. Conclusions: We found no major complications during recovery after balanced propofol-based sedation administered by a gastroenterologist-nurse team. Patients with the identified risk predictors must be monitored carefully.

• Tuberculosis and Respiratory Diseases
• /
• v.45 no.3
• /
• pp.574-582
• /
• 1998

Background: Bronchofiberscopy is a procedure with a chance of airway irritation and it may cause pathophysiologic changes of respiratory system. So we tried to evaluate the influence of bronchofibercopy on $O_2$ saturation, ABGA and PIT by patient's basal status and procedure type. Method: $O_2$ saturation was measured every 1 minute from the left index finger tip with percutaneous oximetry. ABGA was done before and right after the bronchofiberscopy and PIT was done before and within 10 minutes after the bronchofiberscopy. Results: The mean time for bronchofiberscopy procedure was 14.5mim and $SaO_2$ maximally fall to 89.0 below 8% of the baseline after mean time of 8.4min, which was recovered at the end of the procedure. $SaO_2$ change amount was 8.4 % on Non-$O_2$ supply group, which was lower compared to 6.4 % of the $O_2$-supply group without statistically significance. Biopsy Group and BAL group showed more $SaO_2$ fall than washing only group. The level of $PaO_2$ and FEV1 of the patient didn't influence significantly on $SaO_2$ fall during the procedure. ABGA taken before and after the bronchofiberscopy showed mild fall of $PaO_2$ and mild rise of $PaCO_2$. Whereas PFT showed decrease of FEV1(P<0.05) and increase of RV without changes in airway resistance and pulmonary diffusion capacity. Comparing before and after the bronchofiberscopy, the washing group showed no significant changes on PIT, while the biopsy group and the BAL group showed increase of RV & decrease of $FEV_1$ after the bronchofiberscopy. BAL group showed more changing tendency rather than biopsy group although not statistically significant. Conclusion: Bronchofiberscopy is considered as a relatively safe procedure, but it would be better to be done with $O_2$ supply especially in the patient with low $PaO_2$ and in the case of biopsy and BAL.

• Journal of Biomedical Engineering Research
• /
• v.20 no.4
• /
• pp.461-469
• /
• 1999

In this paper, an ECG-NIBP patient monitor is designed. This is an essential equipment to measure and monitor patient's physical condition - electrocardiogram(ECG) wave, heart rate(HR), and noninvasive blood pressure(NIBP) - in ICU, CCU, and operating room. The ECG is an electrical waveform produced by relaxation and contraction of the cardiac muscle. Most physicians diagnose patient's cardiac states from ECG pattern. A blood pressure is one of the clinical indexes measured in a emergency room or operating room. In this paper, the blood pressure is measured in artery by using the nonivasive oscillometric method. The developed patient monitor was inspected and compared with other instruments in operating rooms. The results were 1bpm of maximum difference in the heart rate, 15mmHg in the systolic pressure, 16mmHg in the diastolic pressure, and 25mmHg in the mean blood pressure. But the total results were 0.15bpm of the mean difference in the heart rate, 5mmHg in the systolic pressure, 10mmHg in the diastolic pressure, and 9mmHg in the mean blood pressure. The designed ECG-NIBP patient monitor can measure the ECG wave, HR, and BP. And the multi-tasking module of pulse oximetry . respiration . temperature monitor will be added in the near future.