Seok-Hwa Yoon

Seok-Hwa Yoon


Research Focus & Metrics

Academic Career Length

25Years (2002-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 January 2012 in Korean Journal of Anesthesiology
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Journal Article
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SYSeok-Hwa Yoon
Seok-Hwa Yoon
Septic patients portray instable hemodynamic states because of hypotension or cardiomyopathy, caused by vasodilation, thus, impairing global tissue perfusion and oxygenation threatening functions of critical organs. Therefore, it has become the primary concern of anesthesiologists in conducting anesthesia (induction, maintenance, recovery, and postoperative care), especially in the induction of those who are prone to fall into hemodynamic crisis, due to hemodynamic instability. The anesthesiologist must have a precise anesthetic plan based on a thorough preanesthetic evaluation because many cases are emergent. Primary circulatory status of patients, including mental status, blood pressure, urine output, and skin perfusion, are necessary, as well as more active assessment methods on intravascular volume status and cardiovascular function. Because it is difficult to accurately evaluate the intravascular volume, only by central venous pressure (CVP) measurements, the additional use of transthoracic echocardiography is recommended for the evaluation of myocardial performance and hemodynamic state. In order to hemodynamically stabilize septic patients, adequate fluid resuscitation must be given before induction. Most anesthetic induction agents cause blood pressure decline, however, it may be useful to use drugs, such as ketamine or etomidate, which carry less cardiovascular instability effects than propofol, thiopental and midazolam. However, if blood pressure is unstable, despite these efforts, vasopressors and inotropic agents must be administered to maintain adequate perfusion of organs and cellular oxygen uptake.

1 January 2010 in Korean Journal of Anesthesiology
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Journal Article
Open access
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YNYoontae Nam
Yoontae Nam
AYAnn Misun Yoon
Ann Misun Yoon
YKYoon-Hee Kim
Yoon-Hee Kim
SYSeok-Hwa Yoon
Seok-Hwa Yoon
Respiratory dynamics may be monitored and evaluated indirectly by measuring the peak inspiratory pressure and plateau pressure. In this study, the respiratory dynamics of patients undergoing spinal surgery using a Jackson surgical table were observed with a device after converting their position from supine to prone. The effects of the dynamic compliance and airway resistance were observed from the changes in peak inspiratory pressure and plateau. Twenty five patients were selected as subjects scheduled to undergo lumbar spine surgery. After intubation, the patients were ventilated mechanically with a tidal volume of 10 ml/kg and a respiration rate of 10/min. Anesthesia was maintained with sevoflurane 1.5%, nitrous oxide 2 L/min and oxygen 2 L/min. The peak inspiratory pressure, plateau pressure, resistance, compliance, arterial oxygen tension, carbon dioxide tension, heart rate and arterial blood pressure were measured at 10 minutes after the induction of anesthesia. These parameters were measured again 10 minutes after placing the patient in the prone position. The prone position did not significantly affect the arterial oxygen tension, carbon dioxide tension, blood pressure and heart rate, but significantly increased the peak inspiratory pressure and resistance and decreased the dynamic compliance. The peak inspiratory pressure was increased using a Jackson surgical table to minimize the abdominal pressure when converting from the supine to prone position. This might be due to a decrease in lung and chest compliance as well as an increase in airway resistance.

1 January 2010 in Korean Journal of Anesthesiology
Verified
Journal Article
Open access
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GCGuen Seok Choi
Guen Seok Choi
SPSangil Park
Sangil Park
ELEun Ha Lee
Eun Ha Lee
SYSeok-Hwa Yoon
Seok-Hwa Yoon
Intubating patients with a huge, fixed supraglottic mass causing an obstruction of the glottis is difficult to most anesthesiologists. We attempted awake fiberoptic orotracheal intubation assisted by Glidescope® Videolaryngoscope (GVL) following topical anesthesia with 4% lidocaine spray and remifentanil infusion. The glottis could not be identified by the GVL view. However, by entering toward the right side of the mass with bronchoscope, the glottis was found. Due to stiffness of the mass, we were unable to further enter the area using the bronchoscope. Alternatively, we attempted to expose the glottis by GVL blade and then successfully intubated the patient by manually pressing the cricoids cartilage. GVL is nonetheless an excellent instrument in airway management compared to fiberoptic bronchoscope for patients with a huge and fixed supraglottic mass.

1 January 2011 in Korean Journal of Anesthesiology
Verified
Journal Article
Open access
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GCGuen Seok Choi
Guen Seok Choi
ELEun-Ha Lee
Eun-Ha Lee
Chaeseong LimChaeseong Lim
Chaeseong Lim
SYSeok-Hwa Yoon
Seok-Hwa Yoon
The Glidescope Videolaryngoscope (GVL) is a newly developed video laryngoscope. It offers a significantly improved laryngeal view and facilitates endotracheal intubation in difficult airways, but it is controversial in that it offers an improved laryngeal view in normal airways as well. And the price of GVL is expensive. We hypothesized that intubation carried out by fully experienced anesthesiologists using the GVL with appropriate pre-anesthetic preparations offers an improved laryngeal view and shortened intubation time in normal airways. Therefore, the aim of this study was to compare the GVL with the Macintosh laryngoscope in normal airways and to determine whether GVL can substitute the Macintosh laryngoscope. This study included 60 patients with an ASA physical status of class 1 or 2 requiring tracheal intubation for elective surgery. All patients were randomly allocated into two groups, GVL (group G) or Macintosh (group M). ADS (airway difficulty score) was recorded before induction of anesthesia. The anesthesiologist scored vocal cord visualization using the percentage of glottic opening (POGO) visible and the subjective ease of intubation on a visual analogue scale (VAS). The time required to intubate was recorded by an assistant. There was a significant increase in POGO when using the GVL (P < 0.05). However, there was no difference in the time required for a successful tracheal intubation using the GVL compared with the Macintosh laryngoscope. The VAS score on the ease of intubation was significantly lower for the GVL than for the Macintosh laryngoscope (P < 0.05). GVL could be a first-line tool in normal airways.

Verified
Journal Article
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BHBoohwi Hong
Boohwi Hong
COChahyun Oh
Chahyun Oh
YJYumin Jo
Yumin Jo
WCWoosuk Chung
Woosuk Chung
EPEunhye Park
Eunhye Park
SYSeok-Hwa Yoon
Seok-Hwa Yoon
Intravenous dexamethasone and dexmedetomidine, in conjunction with peripheral nerve blockade, have each been reported to prolong the duration of analgesia. This study tested whether combined use further prolongs analgesia duration after supraclavicular brachial plexus block (BPB) in patients undergoing orthopedic upper extremity surgery. One hundred twenty patients were randomized 1:1:1:1 to Control (saline bolus and midazolam infusion [0.05 mg/kg loading, 20 µg/kg/h thereafter]); DMED (saline bolus and dexmedetomidine infusion [1 μg/kg loading, 0.4 μg/kg/h thereafter]); DEXA (dexamethasone [10 mg] bolus and midazolam infusion); and DMED-DEXA (dexmedetomidine infusion and dexamethasone bolus) groups. The primary outcome was the duration of postoperative analgesia, defined as the time from the end of the BPB to the first dose of analgesia via a patient-controlled device. Median (interquartile range) times to first dose of analgesia in the Control, DMED, DEXA, and DMED-DEXA groups were 8.1 (6.2–11.6), 9.0 (8.1–11.3), 10.7 (8.1–20.5), and 13.2 (11.5–19.1) hours, respectively (p < 0.001). Pairwise comparisons showed significant prolongation of analgesia in the DEXA included groups compared with the non-DEXA included groups (DEXA vs. control, p = 0.045; DEXA vs. DMED, p = 0.045; DMED-DEXA vs. control, p < 0.001; DMED-DEXA vs. DMED, p < 0.001). A mixed effect model showed that dexamethasone was the only significant factor for the prolongation of analgesia (p < 0.001). Intravenous dexamethasone prolonged the analgesia duration of supraclavicular BPB after orthopedic upper extremity surgery. The concurrent use of mild to moderate sedation dose of intravenous dexmedetomidine in addition to intravenous dexamethasone showed no additional benefit to the prolongation of analgesia.

16 October 2022 in Journal of Clinical Medicine
Verified
Journal Article
Open access
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COChahyun Oh
Chahyun Oh
SLSoomin Lee
Soomin Lee
POPyeonghwa Oh
Pyeonghwa Oh
WCWoosuk Chung
Woosuk Chung
YKYoungkwon Ko
Youngkwon Ko
BHBoohwi Hong
Boohwi Hong
(1) Background: Previous studies reported limited performance of arterial pressure waveform-based cardiac output (CO) estimation (FloTrac/Vigileo system; CO-FloTrac) compared with the intermittent thermodilution technique (COint). However, errors due to bolus maneuver and intermittent measurements of COint could limit its use as a reference. The continuous thermodilution technique (COcont) may relieve such limitations. (2) Methods: The performance of CO-FloTrac was retrospectively assessed using continuous recordings of intraoperative physiological data acquired from patients who underwent off-pump coronary artery bypass graft (OPCAB) surgery with CO monitoring using both CO-FloTrac and COcont. Optimal time adjustments between the two measurements were determined based on R-squared values. (3) Results: A total of 134.2 h of data from 30 patients was included in the final analysis. The mean bias was –0.94 (95% CI, −1.35 to −0.52) L/min and the limits of agreements were −3.64 (95% CI, −4.44 to −3.08) L/min and 1.77 (95% CI, 1.21 to 2.57) L/min. The percentage error was 66.1% (95% CI, 52.4 to 85.8%). Depending on the time scale and the size of the exclusion zone, concordance rates ranged from 61.0% to 75.0%. (4) Conclusion: Despite the time adjustments, CO-FloTrac showed non-negligible overestimation, clinically unacceptable precision, and poor trending ability during OPCAB surgery.