1.Association of preoperative metformin use with postoperative mortality and morbidity in type 2 diabetes patients undergoing noncardiac surgery: a retrospective cohort study
Ah Ran OH ; Jungchan PARK ; Suhyun LEE ; Chung Su KIM
Korean Journal of Anesthesiology 2026;79(1):95-103
Background:
Diabetes mellitus (DM) is prevalent among adults, many of whom require surgical interventions. Although metformin may improve postoperative outcomes by reducing inflammation, its effects on postoperative mortality and complications remain unclear. This study aimed to determine whether preoperative metformin use is associated with improved postoperative outcomes after noncardiac surgery.
Methods:
This retrospective study included adult patients with type 2 DM who underwent noncardiac surgery between 2011 and 2019. Patients were assigned to one of two groups based on the use of preoperative metformin at admission. To evaluate dose-related effects, patients in the metformin group were further divided into low- and high-dose groups based on daily dose (< or ≥ 1,000 mg). The primary outcome was one-year mortality after surgery, and the secondary outcomes were 30-day mortality, five-year mortality, and postoperative complications in major organs within 7 d.
Results:
Among 22 944 patients, 12 536 (54.6%) were exposed to preoperative metformin. After inverse probability of treatment weighting, preoperative metformin use was associated with a reduced one-year mortality (hazard ratio: 0.76, 95% CI [0.68–0.85]). For secondary outcomes, metformin use decreased postoperative complications in respiratory (odds ratio [OR]: 0.76, 95% CI [0.61−0.93]) and renal systems (OR: 0.66, 95% CI [0.58−0.74]). In a dose-related analysis, both doses were associated with a lower risk of postoperative mortality, with reductions in respiratory complications primarily due to high-dose metformin (OR: 0.69, 95% CI [0.54−0.89]).
Conclusion
Preoperative use of metformin is associated with reduced postoperative mortality and complications in diabetic patients undergoing noncardiac surgery.
2.Inhalational versus total intravenous anesthesia in noncardiac surgery: a comparative review of clinical outcomes
Korean Journal of Anesthesiology 2026;79(3):264-270
Inhalational anesthetics have long been the cornerstone of general anesthesia in noncardiac surgery owing to their reliable pharmacokinetics, ease of administration, and cardiopulmonary benefits such as bronchodilation and myocardial preconditioning. Total intravenous anesthesia (TIVA), achieved using short-acting agents such as propofol and remifentanil, and supported by target-controlled infusion systems and depth-of-anesthesia monitors, has emerged as a widely adopted alternative. TIVA is associated with improved recovery profiles, reduced incidence of postoperative nausea and vomiting, and potential neuroprotective and immunomodulatory effects. In this review, we compared the pharmacological mechanisms and clinical implications of inhalational anesthesia and TIVA, focusing on myocardial injury after noncardiac surgery and other perioperative outcomes. We summarized evidence from randomized controlled trials, large-scale observational studies, and health system-level analyses across multiple outcome domains: all-cause mortality, cardiovascular complications, pulmonary and renal outcomes, oncological prognosis, and system-level factors, such as cost-effectiveness and environmental impact. While inhalational agents demonstrated advantages in terms of cardioprotection and airway management, TIVA was found to offer potential benefits in select populations, particularly in cancer surgery and neuroanesthesia. No single technique demonstrated consistent superiority across all clinical contexts. Therefore, the selection of anesthetic technique should be personalized based on surgical risk, patient comorbidities, institutional infrastructure, and clinician expertise. Emerging trends in sustainability and precision medicine further underscore the need for individualized evidence-based strategies. By combining mechanistic insights with evidence from clinical practice, this review aimed to provide a balanced framework to guide optimal anesthetic decision-making in noncardiac surgery.
3.Association of preoperative blood glucose level with delirium after non-cardiac surgery in diabetic patients
Soo Jung PARK ; Ah Ran OH ; Jong-Hwan LEE ; Kwangmo YANG ; Jungchan PARK
Korean Journal of Anesthesiology 2024;77(2):226-235
Background:
Hyperglycemia has shown a negative association with cognitive dysfunction. We analyzed patients with high preoperative blood glucose level and hemoglobin A1c (HbA1c) level to determine the prevalence of postoperative delirium.
Methods:
We reviewed a database of 23,532 patients with diabetes who underwent non-cardiac surgery. Acute hyperglycemia was defined as fasting blood glucose > 140 mg/dl or random glucose > 180 mg/dl within 24 h before surgery. Chronic hyperglycemia was defined as HbA1c level above 6.5% within three months before surgery. The incidence of delirium was compared according to the presence of acute and chronic hyperglycemia.
Results:
Of the 23,532 diabetic patients, 21,585 had available preoperative blood glucose level within 24 h before surgery, and 18,452 patients reported levels indicating acute hyperglycemia. Of the 8,927 patients with available HbA1c level within three months before surgery, 5,522 had levels indicating chronic hyperglycemia. After adjustment with inverse probability weighting, acute hyperglycemia was related to higher incidence of delirium (hazard ratio: 1.33, 95% CI [1.10,1.62], P = 0.004 for delirium) compared with controls without acute hyperglycemia. On the other hand, chronic hyperglycemia did not correlate with postoperative delirium.
Conclusions
Preoperative acute hyperglycemia was associated with postoperative delirium, whereas chronic hyperglycemia was not significantly associated with postoperative delirium. Irrespective of chronic hyperglycemia, acute glycemic control in surgical patients could be crucial for preventing postoperative delirium.
4.Perioperative adverse cardiac events and mortality after non-cardiac surgery: a multicenter study
Byungjin CHOI ; Ah Ran OH ; Jungchan PARK ; Jong-Hwan LEE ; Kwangmo YANG ; Dong Yun LEE ; Sang Youl RHEE ; Sang-Soo KANG ; Seung Do LEE ; Sun Hack LEE ; Chang Won JEONG ; Bumhee PARK ; Soobeen SEOL ; Rae Woong PARK ; Seunghwa LEE
Korean Journal of Anesthesiology 2024;77(1):66-76
Background:
Perioperative adverse cardiac events (PACE), a composite of myocardial infarction, coronary revascularization, congestive heart failure, arrhythmic attack, acute pulmonary embolism, cardiac arrest, and stroke during 30-day postoperative period, is associated with long-term mortality, but with limited clinical evidence. We compared long-term mortality with PACE using data from nationwide multicenter electronic health records.
Methods:
Data from 7 hospitals, converted to Observational Medical Outcomes Partnership Common Data Model, were used. We extracted records of 277,787 adult patients over 18 years old undergoing non-cardiac surgery for the first time at the hospital and had medical records for more than 180 days before surgery. We performed propensity score matching and then an aggregated meta‑analysis.
Results:
After 1:4 propensity score matching, 7,970 patients with PACE and 28,807 patients without PACE were matched. The meta‑analysis showed that PACE was associated with higher one-year mortality risk (hazard ratio [HR]: 1.33, 95% CI [1.10, 1.60], P = 0.005) and higher three-year mortality (HR: 1.18, 95% CI [1.01, 1.38], P = 0.038). In subgroup analysis, the risk of one-year mortality by PACE became greater with higher-risk surgical procedures (HR: 1.20, 95% CI [1.04, 1.39], P = 0.020 for low-risk surgery; HR: 1.69, 95% CI [1.45, 1.96], P < 0.001 for intermediate-risk; and HR: 2.38, 95% CI [1.47, 3.86], P = 0.034 for high-risk).
Conclusions
A nationwide multicenter study showed that PACE was significantly associated with increased one-year mortality. This association was stronger in high-risk surgery, older, male, and chronic kidney disease subgroups. Further studies to improve mortality associated with PACE are needed.
5.Predictors of fluid responsiveness in the operating room: a narrative review
Anesthesia and Pain Medicine 2023;18(3):233-243
Prediction of fluid responsiveness has been considered an essential tool for modern fluid management. However, most studies in this field have focused on patients in intensive care unit despite numerous research throughout several decades. Therefore, the present narrative review aims to show the representative method’s feasibility, advantages, and limitations in predicting fluid responsiveness, focusing on the operating room environments. Firstly, we described the predictors of fluid responsiveness based on heart-lung interaction, including pulse pressure and stroke volume variations, the measurement of respiratory variations of inferior vena cava diameter, and the end-expiratory occlusion test and addressed their limitations. Subsequently, the passive leg raising test and mini-fluid challenge tests were also mentioned, which assess fluid responsiveness by mimicking a classic fluid challenge. In the last part of this review, we pointed out the pitfalls of fluid management based on fluid responsiveness prediction, which emphasized the importance of individualized decision-making. Understanding the available representative methods to predict fluid responsiveness and their associated benefits and drawbacks through this review will aid anesthesiologists in choosing the most reliable methods for optimal fluid administration in each patient during anesthesia in the operating room.
6.Association between inflammation-based prognostic markers and mortality of non-cardiac surgery
Ah Ran OH ; Jungchan PARK ; Jong-Hwan LEE ; Kwangmo YANG ; Joonghyun AHN ; Seung-Hwa LEE ; Sangmin Maria LEE
Korean Journal of Anesthesiology 2023;76(6):550-558
Background:
To evaluate the association between inflammation and nutrition-based biomarkers and postoperative outcomes after non-cardiac surgery.
Methods:
Between January 2011 and June 2019, a total of 102,052 patients undergoing non-cardiac surgery were evaluated, with C-reactive protein (CRP), albumin, and complete blood count (CBC) measured within six months before surgery. We assessed their CRP-to-albumin ratio (CAR), neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and modified Glasgow Prognostic Score (mGPS). We determined the best cut-off values by using the receiver operating characteristic (ROC) curves. Patients were divided into high and low groups according to the estimated threshold, and we compared the one-year mortality.
Results:
The one-year mortality of the entire sample was 4.2%. ROC analysis revealed areas under the curve of 0.796, 0.743, 0.670, and 0.708 for CAR, NLR, PLR, and mGPS, respectively. According to the estimated threshold, high CAR, NLR, PLR, and mGPS were associated with increased one-year mortality (1.7% vs. 11.7%, hazard ratio [HR]: 2.38, 95% CI [2.05, 2.76], P < 0.001 for CAR; 2.2% vs. 10.3%, HR: 1.81, 95% CI [1.62, 2.03], P < 0.001 for NLR; 2.6% vs. 10.5%, HR: 1.86, 95% CI [1.73, 2.01], P < 0.001 for PLR; and 2.3% vs. 16.3%, HR: 2.37, 95% CI [2.07, 2.72], P < 0.001 for mGPS).
Conclusions
Preoperative CAR, NRL, PLR, and mGPS were associated with postoperative mortality. Our findings may be helpful in predicting mortality after non-cardiac surgery.
7.Risk factors associated with repeated epidural blood patches using autologous blood
Ah Ran OH ; Jungchan PARK ; Ji Seon JEONG ; Jin Young LEE ; Ji Won CHOI ; Hara KIM ; Woo Seog SIM
The Korean Journal of Pain 2022;35(2):224-230
Background:
An epidural blood patch (EBP) is a procedure to treat intracranial hypotension that does not respond to conservative treatment. EBPs are commonly repeated when the symptoms persist. In this study, we used a large single-center retrospective cohort and evaluated the factors associated with repeated EBPs.
Methods:
From January 2010 to December 2020, a total of 596 patients were treated with EBPs for intracranial hypotension. We evaluated the factors associated with repeated EBPs in the entire population, in patients with spontaneous intracranial hypotension (SIH), and in those with available myelographies.
Results:
In a total of 596 patients, 125 (21.1%) patients required repeated EBPs, and 96/278 (34.5%) in SIH and 29/314 (9.2%) in iatrogenic population. In patients with SIH, international normalized ratio (INR) and cerebrospinal fluid (CSF) leakage on myelographies consistently exhibited significant associations (odds ratio [OR], 1.38; 95% confidence interval [CI], 1.02–1.87; P = 0.043 and OR, 2.18; 95% CI, 1.28–3.69; P = 0.004). In patients with iatrogenic injury, INR and CSF leakage on myelogram did not show difference in repeated EBPs.
Conclusions
Repeated EBPs may be more frequently required in patients with SIH.Prolonged INR and CSF leakage were associated with repeated EBPs in patient with SIH. Further studies are needed to determine factors associated with repeated EBP requirements.
8.Preoperative 2D-echocardiographic assessment of pulmonary arterial pressure in subgroups of liver transplantation recipients
Jungchan PARK ; Myung Soo PARK ; Ji-Hye KWON ; Ah Ran OH ; Seung-Hwa LEE ; Gyu-Seong CHOI ; Jong Man KIM ; Keoungah KIM ; Gaab Soo KIM
Anesthesia and Pain Medicine 2021;16(4):344-352
Background:
The clinical efficacy of preoperative 2D-echocardiographic assessment of pulmonary arterial pressure (PAP) has not been evaluated fully in liver transplantation (LT) recipients.
Methods:
From October 2010 to February 2017, a total of 344 LT recipients who underwent preoperative 2D-echocardiography and intraoperative right heart catheterization (RHC) was enrolled and stratified according to etiology, disease progression, and clinical setting. The correlation of right ventricular systolic pressure (RVSP) on preoperative 2D-echocardiography with mean and systolic PAP on intraoperative RHC was evaluated, and the predictive value of RVSP > 50 mmHg to identify mean PAP > 35 mmHg was estimated.
Results:
In the overall population, significant but weak correlations were observed (R = 0.27; P < 0.001 for systolic PAP, R = 0.24; P < 0.001 for mean PAP). The positive and negative predictive values of RVSP > 50 mmHg identifying mean PAP > 35 mmHg were 37.5% and 49.9%, respectively. In the subgroup analyses, correlations were not significant in recipients of deceased donor type LT (R = 0.129; P = 0.224 for systolic PAP, R = 0.163; P = 0.126 for mean PAP) or in recipients with poorly controlled ascites (R = 0.215; P = 0.072 for systolic PAP, R = 0.21; P = 0.079 for mean PAP).
Conclusion
In LT recipients, the correlation between RVSP on preoperative 2D-echocardiography and PAP on intraoperative RHC was weak; thus, preoperative 2D-echocardiography might not be the optimal tool for predicting intraoperative PAP. In LT candidates at risk of pulmonary hypertension, RHC should be considered.
9.Decreased analgesic requirement in recipient of liver transplantation from monozygotic twin - A case report -
Ah Ran OH ; Justin Sangwook KO ; Gaab-Soo KIM
Anesthesia and Pain Medicine 2020;15(1):83-87
Background:
There have been many reports about decreased analgesic requirements in liver transplant recipients compared with patients undergoing other abdominal surgery.Case: Herein we describe a case in which a 42-year-old man underwent living donor liver transplantation from his monozygotic twin. Because innate pain thresholds may be similar in monozygotic twins, we could effectively investigate postoperative pain in the donor and the recipient. Concordant with previous reports, the recipient used less analgesic than the donor in the present study.
Conclusions
Physicians caring for patients who have received liver transplantation should consider their comparatively low requirement for analgesic, to prevent delayed recovery due to excessive use of analgesic.
10.The Effectiveness of Multidisciplinary Team-Based Education in the Management of Type 2 Diabetes.
Jong Ho KIM ; Yun Jeong NAM ; Won Jin KIM ; Kyung Ah LEE ; A Ran BAEK ; Jung Nam PARK ; Jin Mi KIM ; Seo Young OH ; Eun Heui KIM ; Min Jin LEE ; Yun Kyung JEON ; Bo Hyun KIM ; In Joo KIM ; Yong Ki KIM ; Sang Soo KIM
Journal of Korean Diabetes 2018;19(2):119-133
BACKGROUND: Although clinicians, nurse specialists, pharmacists, and nutritionists expend significant time and resources in optimizing care for patients with diabetes, the effectiveness of integrated diabetes care team approach remains unclear. We assessed the effects of a multidisciplinary team care educational intervention on glycated hemoglobin (HbA1c) levels among diabetes patients. METHODS: We conducted a matched case-control study in Korean patients with type 2 diabetes, comparing the propensity scores pertaining to the effectiveness in reducing HbA1c levels between a group receiving an educational intervention and a control group. We included 40 pairs of patients hospitalized between June 2014 and September 2016. HbA1c values measured at baseline, 3 months, and 6 months were compared between the two groups. RESULTS: The educated group showed an improvement in HbA1c levels compared to the control group at 3 months (6.3 ± 2.3% vs. 9.5 ± 4.0%; P = 0.020) and at 6 months (7.5 ± 1.5% vs. 9.6 ± 3.0%; P = 0.106). There was a significant difference in the change in mean HbA1c from baseline to 3 months between the two groups (−35.7 ± 26.1% vs. −9.1 ± 20.5%; P = 0.013). CONCLUSION: A multidisciplinary team care education intervention was advantageous for improving glucose control in patients with type 2 diabetes, and may help to optimize glycemic control in clinical practice.
Case-Control Studies
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Diabetes Mellitus
;
Education*
;
Glucose
;
Health Education
;
Hemoglobin A, Glycosylated
;
Humans
;
Nurse Clinicians
;
Nutritionists
;
Pharmacists
;
Propensity Score
;
Specialization

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