Comparison of postoperative ascites replacement strategies on time to first flatus after living donor liver transplantation: Albumin vs. lactated Ringer's solution.

INTRODUCTION: There is insufficient evidence regarding the optimal regimen for ascites replacement after living donor liver transplantation (LT) and its effectiveness. The aim of this study is to evaluate the impact of replacing postoperative ascites after LT with albumin on time to first flatus during recovery with early ambulation and incidence of acute kidney injury (AKI). METHODS: Adult patients who underwent elective living donor LT at Seoul National University Hospital from 2019 to 2021 were randomly assigned to either the albumin group or lactated Ringer's group, based on the ascites replacement regimen. Replacement of postoperative ascites was performed for all patients every 4 h after LT until the patient was transferred to the general ward. Seventy percent of ascites drained during the previous 4 h was replaced over the next 4 h with continuous infusion of fluids with a prescribed regimen according to the assigned group. In the albumin group, 30% of a total of 70% of drained ascites was replaced with 5% albumin solution, and remnant 40% was replaced with lactated Ringer's solution. In the lactated Ringer's group, 70% of drained ascites was replaced with only lactated Ringer's solution. The primary outcome was the time to first flatus from the end of the LT and the secondary outcome was the incidence of AKI for up to postoperative day 7. RESULTS: Among the 157 patients who were screened for eligibility, 72 patients were enrolled. The mean age was 63 ± 8.2 years, and 73.0 % (46/63) were male. Time to first flatus was similar between the two groups (66.7 ± 24.1 h vs. 68.5 ± 25.6 h, p = .778). The albumin group showed a higher glomerular filtration rate and lower incidence of AKI until postoperative day 7, compared to the lactated Ringer's group. CONCLUSIONS: Using lactated Ringer's solution alone for replacement of ascites after living donor LT did not reduce the time to first flatus and was associated with an increased risk of AKI. Further research on the optimal ascites replacement regimen and the target serum albumin level which should be corrected after LT is required.

Prevalence and outcomes of chronic comorbid conditions in patients with sepsis in Korea: a nationwide cohort study from 2011 to 2016.

BACKGROUND: Chronic comorbid conditions are common in patients with sepsis and may affect the outcomes. This study aimed to evaluate the prevalence and outcomes of common comorbidities in patients with sepsis. METHODS: We conducted a nationwide retrospective cohort study. Using data from the National Health Insurance Service of Korea. Adult patients (age ≥ 18 years) who were hospitalized in tertiary or general hospitals with a diagnosis of sepsis between 2011 and 2016 were analyzed. After screening of all International Classification of Diseases 10th revision codes for comorbidities, we identified hypertension, diabetes mellitus (DM), liver cirrhosis (LC), chronic kidney disease (CKD), and malignancy as prevalent comorbidities. RESULTS: Overall, 373,539 patients diagnosed with sepsis were hospitalized in Korea between 2011 and 2016. Among them, 46.7% had hypertension, 23.6% had DM, 7.4% had LC, 13.7% had CKD, and 30.7% had malignancy. In-hospital mortality rates for patients with hypertension, DM, LC, CKD, and malignancy were 25.5%, 25.2%, 34.5%, 28.0%, and 33.3%, respectively, showing a decreasing trend over time (P < 0.001). After adjusting for baseline characteristics, male sex, older age, use of mechanical ventilation, and continuous renal replacement therapy, LC, CKD, and malignancy were significantly associated with in-hospital mortality. CONCLUSIONS: Hypertension is the most prevalent comorbidity in patients with sepsis, and it is associated with an increased survival rate. Additionally, liver cirrhosis, chronic kidney disease, and malignancy result in higher mortality rates than hypertension and DM, and are significant risk factors for in-hospital mortality in patients with sepsis.

Real-time machine learning model to predict short-term mortality in critically ill patients: development and international validation.

BACKGROUND: A real-time model for predicting short-term mortality in critically ill patients is needed to identify patients at imminent risk. However, the performance of the model needs to be validated in various clinical settings and ethnicities before its clinical application. In this study, we aim to develop an ensemble machine learning model using routinely measured clinical variables at a single academic institution in South Korea. METHODS: We developed an ensemble model using deep learning and light gradient boosting machine models. Internal validation was performed using the last two years of the internal cohort dataset, collected from a single academic hospital in South Korea between 2007 and 2021. External validation was performed using the full Medical Information Mart for Intensive Care (MIMIC), eICU-Collaborative Research Database (eICU-CRD), and Amsterdam University Medical Center database (AmsterdamUMCdb) data. The area under the receiver operating characteristic curve (AUROC) was calculated and compared to that for the National Early Warning Score (NEWS). RESULTS: The developed model (iMORS) demonstrated high predictive performance with an internal AUROC of 0.964 (95% confidence interval [CI] 0.963-0.965) and external AUROCs of 0.890 (95% CI 0.889-0.891) for MIMIC, 0.886 (95% CI 0.885-0.887) for eICU-CRD, and 0.870 (95% CI 0.868-0.873) for AmsterdamUMCdb. The model outperformed the NEWS with higher AUROCs in the internal and external validation (0.866 for the internal, 0.746 for MIMIC, 0.798 for eICU-CRD, and 0.819 for AmsterdamUMCdb; p < 0.001). CONCLUSIONS: Our real-time machine learning model to predict short-term mortality in critically ill patients showed excellent performance in both internal and external validations. This model could be a useful decision-support tool in the intensive care units to assist clinicians.

Perioperative urinary ketosis and metabolic acidosis in patients fasted for undergoing gynecologic surgery.

BACKGROUND: Our bodies have adaptive mechanisms to fasting, in which glycogen stored in the liver and muscle protein are broken down, but also lipid mobilisation is triggered. As a result, glycerol and fatty acids are released into the bloodstream, increasing the production of ketone bodies in liver. However, there are limited studies on the incidence of perioperative urinary ketosis, the intraoperative blood glucose changes and metabolic acidosis after fasting for surgery in non-diabetic adult patients. METHODS: We conducted a retrospective cohort study involving 1831 patients undergoing gynecologic surgery under general anesthesia from January to December 2022. Ketosis was assessed using a postoperative urine test, while blood glucose levels and acid-base status were collected from intraoperative arterial blood gas analyses. RESULTS: Of 1535 patients who underwent postoperative urinalysis, 912 (59.4%) patients had ketonuria. Patients with ketonuria were younger, had lower body mass index, and had fewer comorbidities than those without ketonuria. After adjustments, younger age, higher body mass index and surgery starting late afternoon were significant risk factors for postoperative ketonuria. Of the 929 patients assessed with intraoperative arterial blood gas analyses, 29.0% showed metabolic acidosis. Multivariable logistic regression revealed that perioperative ketonuria and prolonged surgery significantly increased the risk for moderate-to-severe metabolic acidosis. CONCLUSION: Perioperative urinary ketosis and intraoperative metabolic acidosis are common in patients undergoing gynecologic surgery, even with short-term preoperative fasting. The risks are notably higher in younger patients with lower body mass index. Optimization of preoperative fasting strategies including implementation of oral carbohydrate loading should be considered for reducing perioperative metabolic derangement due to ketosis.

Risk factors of hemodialysis catheter dysfunction in patients undergoing continuous renal replacement therapy: a retrospective study.

BACKGROUND: Continuous renal replacement therapy is a relatively common modality applied to critically ill patients with renal impairment. To maintain stable continuous renal replacement therapy, sufficient blood flow through the circuit is crucial, but catheter dysfunction reduces the blood flow by inadequate pressures within the circuit. Therefore, exploring and modifying the possible risk factors related to catheter dysfunction can help to provide continuous renal replacement therapy with minimal interruption. METHODS: Adult patients who received continuous renal replacement therapy at Seoul National University Hospital between January 2019 and December 2021 were retrospectively analyzed. Patients who received continuous renal replacement therapy via a temporary hemodialysis catheter, inserted at the bedside under ultrasound guidance within 12 h of continuous renal replacement therapy initiation were included. RESULTS: A total of 507 continuous renal replacement therapy sessions in 457 patients were analyzed. Dialysis catheter dysfunction occurred in 119 sessions (23.5%). Multivariate analysis showed that less prolonged prothrombin time (adjusted OR 0.49, 95% CI, 0.30-0.82, p = 0.007) and activated partial thromboplastin time (adjusted OR 1.01, 95% CI, 1.00-1.01, p = 0.049) were associated with increased risk of catheter dysfunction. Risk factors of re-catheterization included vascular access to the left jugular and femoral vein. CONCLUSIONS: In critically ill patients undergoing continuous renal replacement therapy, less prolonged prothrombin time was associated with earlier catheter dysfunction. Use of left internal jugular veins and femoral vein were associated with increased risk of re-catheterization compared to the right internal jugular vein.

The effect of audiovisual feedback of monitor/defibrillators on percentage of appropriate compression depth and rate during cardiopulmonary resuscitation.

BACKGROUND: High quality cardiopulmonary resuscitation (CPR) is one of the key elements of the survival chain in cardiac arrest. Audiovisual feedback of chest compressions have been suggested to be beneficial by increasing the quality of CPR in the simulated cardiac arrests. METHODS: A prospective before and after study was performed to investigate the effect of a real-time audiovisual feedback system on CPR quality during in-hospital cardiac arrest in intensive care units from November 2018 to February 2022. In the feedback period, CPR was performed with the aid of the real-time audiovisual feedback system. The primary outcome was the percentage of compressions with both adequate depth (5.0-6.0 cm) and rate (100-120/minute). RESULTS: A total of 27,295 compressions in 30 cardiac arrests in the no-feedback period and 27,965 compressions in 30 arrests in the feedback period were analyzed. The percentage of compressions with both adequate depth and rate was 11.8% in the feedback period and 16.8% in the no-feedback period (P < 0.01). The percentage of compressions with adequate rate in the feedback period was lower than that in the no-feedback period (67.3% vs. 75.5%, P < 0.01). The percentage of beyond-target depth with the feedback was significantly higher than that without feedback (64.2% vs. 51.4%, P < 0.01). CONCLUSION: Real-time audiovisual feedback system did not increase CPR quality and was associated with a higher percentage of compression depth deeper than the recommended 5.0-6.0 cm. It is essential to explore more effective ways of implementing feedback in real clinical settings to improve of the quality of CPR. TRIAL REGISTRATION: NCT03902873 (study start: Nov. 2018, initial release April 2019, retrospectively registered).

The Profile of Early Sedation Depth and Clinical Outcomes of Mechanically Ventilated Patients in Korea.

BACKGROUND: Current international guidelines recommend against deep sedation as it is associated with worse outcomes in the intensive care unit (ICU). However, in Korea the prevalence of deep sedation and its impact on patients in the ICU are not well known. METHODS: From April 2020 to July 2021, a multicenter, prospective, longitudinal, noninterventional cohort study was performed in 20 Korean ICUs. Sedation depth extent was divided into light and deep using a mean Richmond Agitation-Sedation Scale value within the first 48 hours. Propensity score matching was used to balance covariables; the outcomes were compared between the two groups. RESULTS: Overall, 631 patients (418 [66.2%] and 213 [33.8%] in the deep and light sedation groups, respectively) were included. Mortality rates were 14.1% and 8.4% in the deep and light sedation groups (P = 0.039), respectively. Kaplan-Meier estimates showed that time to extubation (P < 0.001), ICU length of stay (P = 0.005), and death (P = 0.041) differed between the groups. After adjusting for confounders, early deep sedation was only associated with delayed time to extubation (hazard ratio [HR], 0.66; 95% confidence interval [CI], 0.55-0.80; P < 0.001). In the matched cohort, deep sedation remained significantly associated with delayed time to extubation (HR, 0.68; 95% CI, 0.56-0.83; P < 0.001) but was not associated with ICU length of stay (HR, 0.94; 95% CI, 0.79-1.13; P = 0.500) and in-hospital mortality (HR, 1.19; 95% CI, 0.65-2.17; P = 0.582). CONCLUSION: In many Korean ICUs, early deep sedation was highly prevalent in mechanically ventilated patients and was associated with delayed extubation, but not prolonged ICU stay or in-hospital death.

Risk prediction models incorporating institutional case volume for mortality after hip fracture surgery in the elderly.

INTRODUCTION: While higher institutional case volume is associated with better postoperative outcomes in various types of surgery, institutional case volume has been rarely included in risk prediction models for surgical patients. This study aimed to develop and validate the predictive models incorporating institutional case volume for predicting in-hospital mortality and 1-year mortality after hip fracture surgery in the elderly. MATERIALS AND METHODS: Data for all patients (≥ 60 years) who underwent surgery for femur neck fracture, pertrochanteric fracture, or subtrochanteric fracture between January 2008 and December 2016 were extracted from the Korean National Health Insurance Service database. Patients were randomly assigned into the derivation cohort or the validation cohort in a 1:1 ratio. Risk prediction models for in-hospital mortality and 1-year mortality were developed in the derivation cohort using the logistic regression model. Covariates included age, sex, type of fracture, type of anaesthesia, transfusion, and comorbidities such as hypertension, diabetes, coronary artery disease, chronic kidney disease, cerebrovascular disease, and dementia. Two separate models, one with and the other without institutional case volume as a covariate, were constructed, evaluated, and compared using the likelihood ratio test. Based on the models, scoring systems for predicting in-hospital mortality and 1-year mortality were developed. RESULTS: Analysis of 196,842 patients showed 3.6% in-hospital mortality (7084/196,842) and 15.42% 1-year mortality (30,345/196,842). The model for predicting in-hospital mortality incorporating the institutional case volume demonstrated better discrimination (c-statistics 0.692) compared to the model without the institutional case volume (c-statistics 0.688; likelihood ratio test p value < 0.001). The performance of the model for predicting 1-year mortality was also better when incorporating institutional case volume (c-statistics 0.675 vs. 0.674; likelihood ratio test p value < 0.001). CONCLUSIONS: The new institutional case volume incorporated scoring system may help to predict in-hospital mortality and 1-year mortality after hip fracture surgery in the elderly population.

Effect of Hospital Case-Volume on Mortality after Ovarian Cancer Surgery: A Population-Based Retrospective Cohort Study.

OBJECTIVES: The goal of ovarian cancer surgery has recently shifted from optimal cytoreduction to more complete resection. This study attempted to reassess and update the association between surgical case-volume and both in-hospital and long-term mortality after ovarian cancer surgery using recent data. DESIGN: This study is a population-based retrospective cohort study. Participants/Material: Data from all adult patients who underwent ovarian cancer surgery in Korea between 2005 and 2019 were obtained from the national database. A total of 24,620 patients underwent ovarian cancer surgery in 362 hospitals during the period. SETTING: In-hospital and 1-, 3-, 5-year mortality were set as primary and secondary outcomes. METHODS: Hospitals were categorized into high-volume (>90 cases/year), medium-volume (20-90 cases/year), and low-volume (<20 cases/year) centers considering overall distribution of case-volume. Postoperative in-hospital and long-term mortality were analyzed using logistic regression after adjusting for potential risk factors. RESULTS: Compared to high-volume centers (0.54%), in-hospital mortality was significantly higher in medium-volume (1.40%; adjusted odds ratio, 2.92; confidence interval, 1.82-3.73; p < 0.001) and low-volume (1.61%; adjusted odds ratio, 2.94; confidence interval, 2.07-4.17; p < 0.001) centers. In addition, 1-year mortality was 6.26%, 7.06%, and 7.94% for high-volume, medium-volume, and low-volume centers, respectively, and the differences among the groups were significant. However, case-volume effect was not apparent in 3- and 5-year mortality after ovarian cancer surgery. LIMITATIONS: Lacking clinical information such as staging or histologic diagnosis due to the nature of the administrative data should be considered in interpreting the data. CONCLUSIONS: Case-volume effect was observed for in-hospital and 1-year mortality after ovarian cancer surgery, while it was not clearly found in 3- or 5-year mortality. Dilution of the case-volume effect might be attributed to the high accessibility to care.

Pre and postoperative lactate levels and lactate clearance in predicting in-hospital mortality after surgery for gastrointestinal perforation.

BACKGROUND: This study aimed to compare the prognostic significance of pre and postoperative lactate levels and postoperative lactate clearance in the prediction of in-hospital mortality after surgery for gastrointestinal (GI) perforation. METHODS: Among patients who underwent surgery for GI perforation between 2013 and 2017, only patients whose lactate were measured before and after surgery were included and divided into an in-hospital mortality group and a survival group. Data on demographics, comorbidities, pre and postoperative laboratory test results, and operative findings were collected. Risk factors for in-hospital mortality were identified, and receiver-operating characteristic (ROC) curve analysis was performed for pre and postoperative lactate levels and postoperative lactate clearance. RESULTS: Of 104 included patients, 17 patients (16.3%) died before discharge. The in-hospital mortality group demonstrated higher preoperative lactate (6.3 ± 5.1 vs. 3.5 ± 3.2, P = 0.013), SOFA score (4.5 ± 1.7 vs. 3.4 ± 2.3, P = 0.004), proportions of patients with lymphoma (23.5% vs. 2.3%, P = 0.006), and rates of contaminated ascites (94.1% vs. 68.2%, P = 0.036) and lower preoperative hemoglobin (10.4 ± 1.6 vs. 11.8 ± 2.4, P = 0.018) compare to the survival group. Multivariate analysis revealed that postoperative lactate (HR 1.259, 95% CI 1.084-1.463, P = 0.003) and preoperative hemoglobin (HR 0.707, 95% CI 0.520-0.959, P = 0.026) affected in-hospital mortality. In the ROC curve analysis, the largest area under the curve (AUC) was shown in the postoperative lactate level (AUC = 0.771, 95% CI 0.678-0.848). CONCLUSION: Of perioperative lactate levels in patients underwent surgery for GI perforation, postoperative lactate was the strongest predictor for in-hospital mortality.

Long-term impacts of appendectomy associated with increased incidence of inflammatory bowel disease, infection, and colorectal cancer.

PURPOSE: Although the appendix has been suggested to play a role in maintaining the gut microbiome and immune system, the ramifications of appendectomy on the development inflammatory bowel disease, sepsis, and colorectal cancer are yet to be determined. The purpose of this study was to evaluate the potential long-term impacts of appendectomy, with a focus on inflammatory bowel disease, infection, and colorectal cancer, using the National Healthcare Insurance Service (NHIS) database of Korea. METHODS: The National Healthcare Insurance Service database in Korea was used for analysis. Adult patients who received appendectomy between 2005 and 2013 were identified. The control group consisted of patients who did not receive appendectomy were matched by baseline characteristics including comorbidities and frequency of healthcare resource utilization. The primary outcome was the incidence-rate ratio (IRR) of Crohn's disease, ulcerative colitis, Clostridium difficile infection, sepsis, and colorectal cancer after appendectomy or the index date. RESULTS: We identified 914,208 patients who underwent appendectomy, and after matching with control patients, a total of 486,844 patients were included for analysis. Patients who underwent appendectomy showed a significantly higher incidence of Crohn's disease (IRR 4.40, 95% confidence interval (CI) 3.78-5.13) and ulcerative colitis (IRR 1.78, 95% CI 1.63-1.93) compared to the control group during the 5-year follow-up period. The associations between appendectomy and Clostridium difficile infection, sepsis, and colorectal cancer were all found to be significant. CONCLUSION: Patients who underwent appendectomy may be at increased risk for developing Crohn's disease, ulcerative colitis, Clostridium difficile infection, sepsis, and colorectal cancer.

Effects of thermal softening of endotracheal tubes on postoperative sore throat: A randomized double-blinded trial.

BACKGROUND: Postoperative throat complications after intubation are undesirable but frequent outcomes. A randomized, double-blinded study was performed to determine whether thermal softening of endotracheal tubes reduced throat complications after intubation. METHODS: Patients (n = 196) undergoing nasal surgery were randomly allocated into the control group and thermal softening groups. Sore throat and hoarseness were evaluated 1 and 24 hours after extubation. The severity of sore throat was evaluated using the numeric rating scale (NRS). The primary outcome was the incidence of sore throat 1 hour after extubation and sore throat was defined as a painful or scratchy feeling in the throat. The secondary outcomes were the incidence of hoarseness 1 hour after extubation, the incidence of sore throat and hoarseness 24 hours after extubation, severity of sore throat, and vocal cord injuries. RESULTS: The incidence of sore throat 1 hour after extubation was lower in the thermal softening group than in the control group (35.1% vs 52.7%, P = .02). Moreover, thermal softening decreased the mean NRS score for sore throat in the thermal softening group by 10% an hour after extubation (thermal softening group, 1.29 [95% CI, 0.88-1.70] vs control group, 2.33 [95% CI, 1.77-2.89]; P < .01). At 24 hours after extubation, the incidence of sore throat (38.3% vs 40.7%, P = .77) and hoarseness (34.0% vs 35.2%, 0.95 [0.52-1.74], P = .74) were comparable between the two groups. CONCLUSIONS: Intubation using endotracheal tubes with thermal softening significantly decreased the incidence of sore throat 1 hour after extubation when compared with endotracheal tubes without thermal softening.

Effect of Sedatives on In-hospital and Long-term Mortality of Critically Ill Patients Requiring Extended Mechanical Ventilation for ≥ 48 Hours.

BACKGROUND: The purpose of this study was to assess the correlation between sedatives and mortality in critically ill patients who required mechanical ventilation (MV) for ≥ 48 hours from 2008 to 2016. METHODS: We conducted a nationwide retrospective cohort study using population-based healthcare reimbursement claims database. Data from adult patients (aged ≥ 18) who underwent MV for ≥ 48 hours between 2008 and 2016 were identified and extracted from the National Health Insurance Service database. The benzodiazepine group consisted of patients who were administered benzodiazepines for sedation during MV. All other patients were assigned to the non-benzodiazepine group. RESULTS: A total of 158,712 patients requiring MV for ≥ 48 hours were admitted in 55 centers in Korea from 2008 to 2016. The benzodiazepine group had significantly higher in-hospital and one-year mortality compared to the non-benzodiazepine group (37.0% vs. 34.3%, 55.0% vs. 54.4%, respectively). Benzodiazepine use decreased from 2008 to 2016, after adjusting for age, sex, and mean Elixhauser comorbidity index in the Poisson regression analysis (incidence rate ratio, 0.968; 95% confident interval, 0.954-0.983; P < 0.001). Benzodiazepine use, older age, lower case volume (≤ 500 cases/year), chronic kidney disease, and higher Elixhauser comorbidity index were common significant risk factors for in-hospital and one-year mortality. CONCLUSION: In critically ill patients undergoing MV for ≥ 48 hour, the use of benzodiazepines for sedation, older age, and chronic kidney disease were associated with higher in-hospital mortality and one-year mortality. Further studies are needed to evaluate the impact of benzodiazepines on the mortality in elderly patients with chronic kidney disease requiring MV for ≥ 48 hours.

Pharmacokinetics of human antithrombin III concentrate in the immediate postoperative period after liver transplantation.

AIMS: Antithrombin III (AT-III) concentrates have been used to prevent critical thrombosis in the immediate post-liver transplantation period without clear evidence regarding the optimal dose or administration scheme. The relationship between the AT-III dosage and the plasma activity levels during the period was evaluated in this study. METHODS: The plasma AT-III activity levels and clinical data obtained from patients who received liver transplantation from January 2017 to September 2018 were retrospectively analysed. A population pharmacokinetic (PK) model was developed using nonlinear mixed-effects method and externally validated thereafter. Several dosing scenarios were simulated to maintain the plasma AT-III activity level within the normal range using the developed PK model to search for an optimal AT-III dosing regimen. RESULTS: The plasma AT-III activity levels were best described by a single compartment model with first order elimination kinetics. The recovery of endogenous AT-III level during the postoperative days was modelled using an Emax model. The typical values (95% confidence interval) of volume of distribution and clearance were 3.86 (3.40-4.32) L, and 0.129 (0.111-0.147) L h-1 , respectively. Serum albumin and body weight had significant effect on clearance and were included in the model. External validation of the proposed model demonstrated adequate prediction performance. Furthermore, simulation of previously suggested or modified dosing scenarios showed successful maintenance of AT-III activity level within the normal range. CONCLUSION: A population PK model of AT-III concentrate was developed using data from liver recipients. Dosing scenarios simulated in our study may help establish a practical guide for AT-III concentrate titration after liver transplantation.

Impact of Mitral Valve Repair Case Volume on Postoperative Mortality　- A Nationwide Korean Cohort Study.

BACKGROUND: Although mitral valve repair is recommended over replacement due to better outcomes, repair rates vary significantly among centers. This study examined the effect of institutional mitral valve repair volume on postoperative mortality.Methods and Results:All cases of adult mitral valve repair performed in Korea between 2009 and 2016 were analyzed. The association between case volume and 1-year mortality was analyzed after categorizing centers according to the number of mitral valve repairs performed as low-, medium-, or high-volume centers (<20, 20-40, and >40 cases/year, respectively). The effect of case volume on cumulative all-cause mortality was also assessed. In all, 6,041 mitral valve repairs were performed in 86 centers. The 1-year mortality in low-, medium-, and high-volume centers was 10.1%, 8.7%, and 4.7%, respectively. Low- and medium-volume centers had increased risk of 1-year mortality compared with high-volume centers, with odds ratios of 2.80 (95% confidence interval [CI] 2.15-3.64; P<0.001) and 2.66 (95% CI 1.94-3.64; P<0.001), respectively. The risk of cumulative all-cause mortality was also worse in low- and medium-volume centers, with hazard ratios of 1.96 (95% CI 1.68-2.29; P<0.001) and 1.77 (95% CI 1.47-2.12; P<0.001), respectively. CONCLUSIONS: Lower institutional case volume was associated with higher mortality after mitral valve repair. A minimum volume standard may be required for hospitals performing mitral valve repair to guarantee adequate outcome.

Incidence and Outcomes of Sepsis in Korea: A Nationwide Cohort Study From 2007 to 2016.

OBJECTIVES: This study aimed to estimate the incidence and clinical outcomes of sepsis in Korea from 2007 to 2016. DESIGN: Retrospective observational study. SETTING: Nationwide study with population-based healthcare reimbursement claims database. PATIENTS: Using data from the National Health Insurance Service of Korea, patients who were hospitalized with a diagnosis of sepsis from 2007 to 2016 were analyzed. The incidence of sepsis was calculated using mid-year census population and analyzed according to year, age, and sex. The Elixhauser Comorbidity Index score was calculated to adjust for the impact of comorbidities on clinical outcome. In-hospital mortality, hospital length of stay, ICU admission rates, and risk factors for in-hospital mortality were also analyzed. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: The incidence of sepsis increased from 173.8 per 100,000 population in 2007 to 233.6 per 100,000 population in 2016. In-hospital mortality decreased from 30.9% in 2007 to 22.6% in 2016 (p < 0.0001). From 2007 to 2016, hospital length of stay and ICU admission rates associated with sepsis decreased from 26.0 ± 33.5 days to 21.3 ± 24.4 days (p < 0.0001) and from 16.2% to 12.7% (p < 0.0001), respectively. Male sex, age greater than 50 years, Elixhauser Comorbidity Index greater than 10, and mechanical ventilation were identified as risk factors for in-hospital mortality after adjusting for baseline characteristics. CONCLUSIONS: The incidence of sepsis in Korea increased from 2007 to 2016, while the associated in-hospital mortality, hospital length of stay, and ICU admission rates decreased.

Effect of Institutional Kidney Transplantation Case-Volume on Post-Transplant Graft Failure: a Retrospective Cohort Study.

BACKGROUND: The impact of institutional case volume to graft failure rate after adult kidney transplantation is relatively unclear compared to other solid organ transplantations. METHODS: A retrospective cohort study of 13,872 adult kidney transplantations in Korea was performed. Institutions were divided into low- (< 24 cases/year), medium- (24-60 cases/year), and high- (> 60 cases/year) volume centers depending on the annual case volume. One-year graft failure rate was defined as the proportion of patients who required dialysis or re-transplantation at one year after transplantation. Postoperative in-hospital mortality and long-term graft survival were also measured. RESULTS: After adjustment, one year graft failure was higher in low-volume centers significantly (adjusted odds ratio [aOR], 1.50; 95% confidence interval [CI], 1.26-1.78; P < 0.001) and medium-volume centers (aOR, 1.87; 95% CI, 1.57-2.23; P < 0.001) compared to high-volume centers. Low-volume centers had significantly higher mortality (aOR, 1.75; 95% CI, 1.15-2.66; P = 0.01) than that of high-volume centers after adjustment. Long-term graft survival of up to 9 years was superior in high-volume centers compared to low- and medium-volume centers (P < 0.001). CONCLUSION: Higher-case volume centers were associated with lower one-year graft failure rate, lower in-hospital mortality, and higher long-term graft survival after kidney transplantation.

Effect of Institutional Case Volume on In-Hospital and Long-Term Mortality in Critically Ill Patients Requiring Mechanical Ventilation for 48 Hours or More.

BACKGROUND: The purpose of this study was to evaluate whether institutional case volume affects clinical outcomes in patients receiving mechanical ventilation for 48 hours or more. METHODS: We conducted a nationwide retrospective cohort study using the database of Korean National Healthcare Insurance Service. Between January 2007 and December 2016, 158,712 adult patients were included at 55 centers in Korea. Centers were categorized according to the average annual number of patients: > 500, 500 to 300, and < 300. RESULTS: In-hospital mortality rates in the high-, medium-, and low-volume centers were 32.6%, 35.1%, and 39.2%, respectively. After adjustment, in-hospital mortality was significantly higher in low-volume centers (adjusted odds ratio [OR], 1.332; 95% confidence interval [CI], 1.296-1.368; P < 0.001) and medium-volume centers (adjusted OR, 1.125; 95% CI, 1.098-1.153; P < 0.001) compared to high-volume centers. Long-term survival for up to 8 years was better in high-volume centers. CONCLUSION: Centers with higher case volume (> 500 patients/year) showed lower in-hospital mortality and long-term mortality, compared to centers with lower case volume (< 300 patients/year) in patients who required mechanical ventilation for 48 hours or more.

Procalcitonin-Guided Treatment on Duration of Antibiotic Therapy and Cost in Septic Patients (PRODA): a Multi-Center Randomized Controlled Trial.

BACKGROUND: The objective of this study was to establish the efficacy and safety of procalcitonin (PCT)-guided antibiotic discontinuation in critically ill patients with sepsis in a country with a high prevalence of antimicrobial resistance and a national health insurance system. METHODS: In a multi-center randomized controlled trial, patients were randomly assigned to a PCT group (stopping antibiotics based on a predefined cut-off range of PCT) or a control group. The primary end-point was antibiotic duration. We also performed a cost-minimization analysis of PCT-guided antibiotic discontinuation. RESULTS: The two groups (23 in the PCT group and 29 in the control group) had similar demographic and clinical characteristics except for need for renal replacement therapy on ICU admission (46% vs. 14%; P = 0.010). In the per-protocol analysis, the median duration of antibiotic treatment for sepsis was 4 days shorter in the PCT group than the control group (8 days; interquartile range [IQR], 6-10 days vs. 14 days; IQR, 12-21 days; P = 0.001). However, main secondary outcomes, such as clinical cure, 28-day mortality, hospital mortality, and ICU and hospital stays were not different between the two groups. In cost evaluation, PCT-guided therapy decreased antibiotic costs by USD 30 (USD 241 in the PCT group vs. USD 270 in the control group). The results of the intention-to-treat analysis were similar to those obtained for the per-protocol analysis. CONCLUSION: PCT-guided antibiotic discontinuation in critically ill patients with sepsis could reduce the duration of antibiotic use and its costs with no apparent adverse outcomes. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT02202941.

Perioperative red blood cell transfusion and mortality following heart transplantation: A retrospective nationwide population-based study between 2007 and 2016 in Korea.

BACKGROUND: Patients undergoing heart transplantation (HT) frequently receive perioperative red blood cell (RBC) transfusions, but the impact of perioperative transfusion on clinical outcomes after HT remains unclear. METHODS: All adult HTs performed in Korea between 2007 and 2016 were analyzed using data from the National Health Insurance Service. Patients were classified into four groups based on the number of RBC units transfused during hospital admission for HT: 0, 1 to 2, 3 to 5, and greater than or equal to 6 units. In-hospital and long-term mortality rates were compared among the groups. RESULTS: In total, 833 adults HTs were included in the study. The overall in-hospital mortality rate was 8.4% (70 of 833), with no mortality occurring in patients who received no transfusion. The in-hospital mortality rate was higher in patients requiring greater than or equal to 6 units (25.1%) than in patients who received 1 to 2 units (0.3%) and 3 to 5 units (2.7%; P < .001). Patients who received greater than or equal to 6 units of RBCs had a significantly higher risk of all-cause mortality after HT compared to patients who received no transfusion (hazard ratio [95% confidence interval], 5.99 [1.46-24.56]; P = .012). Long-term survival rate was also lower in patients who received transfusions of greater than or equal to 6 units of RBCs than in patients who received no transfusion (P < .001). CONCLUSIONS: Perioperative transfusion of greater than or equal to 6 units of RBCs may be associated with an increased risk of in-hospital and long-term mortality after HT.