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.

VASOPRESSOR REDUCTION EFFECT OF POLYMYXIN B HEMOPERFUSION IN PATIENTS WITH PERITONITIS-INDUCED SEPTIC SHOCK: A PROPENSITY SCORE-MATCHED ANALYSIS.

ABSTRACT: Background : This study aimed to evaluate the effect of polymyxin B hemoperfusion (PMX-HP) in patients with peritonitis-induced septic shock who still required high-dose vasopressors after surgical source control. Methods : This retrospective study included adult patients admitted to the surgical intensive care unit (ICU) at Seoul National University Hospital between July 2014 and February 2021 who underwent major abdominal surgery to control the source of sepsis. Patients were divided into two groups based on whether PMX-HP was applied after surgery or not. The primary and secondary endpoints were the vasopressor reduction effect, and in-ICU mortality, respectively. Propensity score matching was performed to compare the vasopressor reduction effect. Results : A total of 338 patients met the inclusion criteria, of which 23 patients underwent PMX-HP postoperatively, whereas 315 patients did not during the study period. Serum norepinephrine concentration decreased over time regardless of whether PMX-HP was applied. However, it decreased more rapidly in the PMX-HP(+) group than in the PMX-HP(-) group. There were no significant differences in demographics including age, sex, body mass index, and most underlying comorbidities between the two groups. Risk factors for in-ICU mortality were identified by comparing patient characteristics and perioperative factors between the two groups using multivariate analysis. Conclusion : For patients with peritonitis-induced septic shock, PMX-HP rapidly reduces the requirement of vasopressors immediately after surgery but does not reduce in-ICU mortality. This effect could potentially accelerate recovery from shock, reduce sequelae from vasopressors, and ultimately improve quality of life after discharge.

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.

Timing of prophylactic antibiotics administration and suspected systemic infection after percutaneous biliary intervention.

BACKGROUND/PURPOSE: Prophylactic antibiotics administration before percutaneous biliary intervention (PBI) is currently recommended, but the underlying evidence is mostly extrapolated from prophylactic antibiotics before surgery. The aim of this study was to evaluate the impact of prophylactic antibiotics administration timing on the incidence of suspected systemic infection after PBI. METHODS: The incidence of suspected systemic infection after PBI was compared in patients who received prophylactic antibiotics at four different time intervals between antibiotics administration and skin puncture for PBI. Suspected post-intervention systemic infection was assessed according to predetermined clinical criteria. RESULTS: There were 98 (21.6%) suspected systemic infections after 454 PBIs in 404 patients. There were significant differences among the four groups in the incidence of suspected systemic infection after the intervention (p = .020). Fever was the most common sign of suspected systemic infection. Administration of prophylactic antibiotics more than an hour before PBI was identified as an independent risk factor of suspected systemic infection after adjusting for other relevant factors (adjusted odds ratio = 10.54; 95% confidence interval, 1.40-78.86). CONCLUSIONS: The incidence of suspected systemic infection after the PBI was significantly lower when prophylactic antibiotics were administered within an hour before the intervention.

The Association Between Institutional Case Volume of Hematopoietic Stem Cell Transplantation and Mortality.

BACKGROUND: Hematopoietic stem cell transplantation (HSCT) is a complex, high-risk procedure with significant morbidity and mortality. The positive impact of higher institutional case volume on survival has been reported in various high-risk procedures. The association between annual institutional HSCT case volume and mortality was analyzed using the National Health Insurance Service database. METHODS: Data on 16,213 HSCTs performed in 46 Korean centers between 2007 and 2018 were extracted. Centers were divided into low- or high-volume centers using an average of 25 annual cases as the cut-off. Adjusted odds ratios (OR) for 1-year mortality after allogeneic and autologous HSCT were estimated using multivariable logistic regression. RESULTS: For allogeneic HSCT, low-volume centers (≤25 cases/y) were associated with higher 1-year mortality (adjusted OR 1.17, 95% CI 1.04-1.31, P = .008). However, low-volume centers did not show higher 1-year mortality (adjusted OR 1.03, 95% CI 0.89-1.19, P = .709) for autologous HSCT. Long-term mortality after HSCT was significantly worse in low-volume centers (adjusted hazard ratio [HR] 1.17, 95% CI, 1.09-1.25, P < .001 and adjusted HR 1.09, 95% CI, 1.01-1.17, P = .024, allogeneic and autologous HSCT, respectively) compared with high-volume centers. CONCLUSION: Our data suggest that higher institutional HSCT case volume seems to be associated with better short- and long-term survival.

Early Postoperative Fever and Atelectasis in Patients Undergoing Upper Abdominal Surgery.

BACKGROUND: Atelectasis is a common complication after upper abdominal surgery and considered as a cause of early postoperative fever (EPF) within 48 hours after surgery. However, the pathophysiologic mechanism of how atelectasis causes fever remains unclear. STUDY DESIGN: Data for adult patients who underwent elective major upper abdominal surgery under general anesthesia at Seoul National University Hospital between January and December of 2021 were retrospectively analyzed. The primary outcome was the association between fever and atelectasis within 2 days after surgery. RESULTS: Of 1,624 patients, 810 patients (49.9%) developed EPF. The incidence of atelectasis was similar between the fever group and the no-fever group (51.6% vs 53.9%, p = 0.348). Multivariate analysis showed no significant association between atelectasis and EPF. Culture tests (21.7% vs 8.8%, p < 0.001) and prolonged use of antibiotics (25.9% vs 13.9%, p < 0.001) were more frequent in the fever group compared to the no-fever group. However, the frequency of bacterial growth on culture tests and postoperative pulmonary complications within 7 days were similar between the two groups. CONCLUSIONS: EPF after major upper abdominal surgery was not associated with radiologically detected atelectasis. EPF also was not associated with the increased risk of postoperative pulmonary complications, bacterial growth on culture studies, or prolonged length of hospital stay.

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.

Institutional case volume and mortality after aortic and mitral valve replacement: a nationwide study in two Korean cohorts.

BACKGROUND: There are only a handful of published studies regarding the volume-outcome relationship in heart valve surgery. We evaluated the association between institutional case volume and mortality after aortic valve replacement (AVR) and mitral valve replacement (MVR). METHODS: Two separate cohorts of all adults who underwent AVR or MVR, respectively, between 2009 and 2016 were analyzed using a Korean healthcare insurance database. Hospitals performing AVRs were divided into three groups according to the average annual case volume: the low- (< 20 cases/year), medium- (20-70 cases/year), and high-volume centers (> 70 cases/year). Hospitals performing MVRs were also grouped as the low- (< 15 cases/year), medium- (15-40 cases/year), or high-volume centers (> 40 cases/year). In-hospital mortality after AVR or MVR were compared among the groups. RESULTS: In total, 7875 AVR and 5084 MVR cases were analyzed. In-hospital mortality after AVR was 8.3% (192/2318), 4.0% (84/2102), and 2.6% (90/3455) in the low-, medium-, and high-volume centers, respectively. The adjusted risk was higher in the low- (OR 2.31, 95% CI 1.73-3.09) and medium-volume centers (OR 1.53, 95% CI 1.09-2.15) compared to the high-volume centers. In-hospital mortality after MVR was 9.3% (155/1663), 6.3% (94/1501), and 2.9% (56/1920) in the low-, medium-, and high-volume centers, respectively. Compared to the high-volume centers, the medium- (OR 1.97, 95% CI 1.35-2.88) and low-volume centers (OR 2.29, 95% CI 1.60-3.27) showed higher adjusted risk of in-hospital mortality. CONCLUSIONS: Lower case volume is associated with increased in-hospital mortality after AVR and MVR. The results warrant a comprehensive discussion regarding regionalization/centralization of cardiac valve replacements to optimize patient outcomes.

Hospital case-volume and mortality after lung cancer surgery: A population-based retrospective cohort study.

OBJECTIVES: Recent advances in lung cancer treatment warrants reassessment of the volume-outcome association in lung cancer surgery. This study reassessed the relationship between surgical case-volume and both in-hospital and long-term mortality after lung cancer surgery using a current database to reflect recent advances. MATERIALS AND METHODS: Using the database of the National Health Insurance Service in Korea, data of all adult patients who underwent lung cancer surgery in Korea between 2005 and 2019 were obtained. Hospitals were categorized by the annual number of lung cancer surgeries. Risk-adjusted in-hospital and 1, 3, 5-year mortality after surgery were assessed. RESULTS: A total of 84,194 lung cancer surgeries were performed in 163 centers during the study period. High-volume centers were defined as > 200 cases/year, medium-volume centers as 60-200 cases/year, and low-volume centers as < 60 cases/year. After adjustment, in-hospital mortality was significantly lower in high-volume centers (1.03%) compared to medium-volume centers (2.06%, adjusted odds ratio [OR], 1.43; 95% confidence interval [CI], 1.23-1.65; P < 0.001), and low-volume centers (3.08%, OR, 1.32; 95% CI, 1.16-1.51; P < 0.001). Long-term mortality was also significantly lower in high-volume centers compared to the other groups. CONCLUSION: High-volume centers showed lower in-hospital and long-term mortality compared to centers with less case-volume.

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.

Institutional case volume-incorporated mortality risk prediction model for cardiac surgery.

BACKGROUND: Most risk prediction models predicting short-term mortality after cardiac surgery incorporate patient characteristics, laboratory data, and type of surgery, but do not account for surgical experience. Considering the impact of case volume on patient outcome after high-risk procedures, we attempted to develop a risk prediction model for mortality after cardiac surgery that incorporates institutional case volume. METHODS: Adult patients who underwent cardiac surgery from 2009 to 2016 were identified. Patients who underwent cardiac surgery (n = 57,804) were randomly divided into the derivation cohort (n = 28,902) or the validation cohorts (n = 28,902). A risk prediction model for in-hospital mortality and 1-year mortality was developed from the derivation cohort and the performance of the model was evaluated in the validation cohort. RESULTS: The model demonstrated fair discrimination (c-statistics, 0.76 for in-hospital mortality in both cohorts; 0.74 for 1-year mortality in both cohorts) and acceptable calibration. Hospitals were classified based on case volume into 50 or less, 50-100, 100-200, or more than 200 average cardiac surgery cases per year and case volume was a significant variable in the prediction model. CONCLUSIONS: A new risk prediction model that incorporates institutional case volume and accurately predicts in-hospital and 1-year mortality after cardiac surgery was developed and validated.

The association between hospital case-volume and postoperative outcomes after esophageal cancer surgery: A population-based retrospective cohort study.

BACKGROUND: Recent advances in esophageal cancer treatment require a reevaluation of the relationship between institutional case-volume and patient outcome. The aim of this study was to analyze and update the association between surgical case-volume and both in-hospital and long-term mortality after esophagectomy for esophageal cancer. METHODS: Data of all adult patients who received esophageal cancer surgery in Korea between 2004 and 2017 were extracted from the database of the National Health Insurance Service. Hospitals were categorized into three groups according to the average annual number of esophageal cancer surgery: low-volume (<12 cases/year), medium-volume (12-48 cases/year), and high-volume centers (>48 cases/year). Postoperative in-hospital and 1-, 3-, and 5-year mortality were analyzed according to the categorized groups using logistic regression. RESULTS: In total, 11, 346 esophageal cancer surgeries in 122 hospitals were analyzed. In-hospital mortality in the high-, medium-, and low-volume centers were 3.4%, 6.4%, and 11.1%, respectively. In-hospital mortality was significantly higher in low- volume (adjusted odds ratio, 3.91; confidence interval, 3.18-4.80; p < 0.001) and medium volume (adjusted odds ratio, 2.21; confidence interval, 1.80-2.74, p < 0.001) centers compared to high-volume centers. Patients who received esophageal cancer surgery in a low-or medium-volume center also had higher 1-, 3-, and 5-year mortality compared to patients who received the surgery in a high-volume center. Conclusions Centers with lower case-volume showed higher in-hospital mortality and long-term mortality after esophageal cancer surgery.

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.

Effect of institutional case volume on mid-term mortality after coronary artery bypass grafting surgery.

OBJECTIVE: The impact of center case volume on mid-term postoperative outcome after coronary artery bypass grafting surgery (CABG) is still controversial and requires investigation. The aim of this study was to compare mid-term survival after CABG according to the institutional annual CABG case volume. METHODS: Adult patients (≥ 18 years) who underwent CABG from 2009 to 2016 were identified by searching National Health Insurance database of Korea for CABG procedure codes. Hospitals were classified into three groups based on annual case volume; low-volume centers (< 20 cases/year), medium-volume centers (20-50 cases/year), and high-volume centers (> 50 cases/year). RESULTS: A total of 22,575 CABG were performed in 95 centers during the study period, and 14,697 (65.1%) cases performed at 15 high-volume centers, 5,262 (23.3%) cases at 26 medium-volume centers, and 2,616 (11.6%) cases at 54 low-volume centers. The overall 1-year mortality rate was the lowest in high-volume centers (6.5%), followed by medium-volume centers (10.6%) and low-volume centers (15.2%). Logistic regression identified medium-volume centers (adjusted OR 1.30 [95% CI 1.15-1.49], P < 0.01) and low-volume centers (adjusted OR 1.75 [95% CI 1.51-2.03], P < 0.01) as risk factors for 1-year mortality after CABG compared to high-volume centers. In the Cox proportional hazard model, low- and medium-volume centers were significantly risk factors for poor survival (adjusted HR 1.41 [95% CI 1.31-1.54], P < 0.01 and HR 1.26 [95% CI 1.17-1.35], P < 0.01 for low- and medium-volume centers, respectively). CONCLUSIONS: Higher institutional case volume of CABG was associated with lower mid-term mortality.

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.

The association between hospital case volume and in-hospital and one-year mortality after hip fracture surgery.

AIMS: Hospital case volume is shown to be associated with postoperative outcomes in various types of surgery. However, conflicting results of volume-outcome relationship have been reported in hip fracture surgery. This retrospective cohort study aimed to evaluate the association between hospital case volume and postoperative outcomes in patients who had hip fracture surgery. We hypothesized that higher case volume would be associated with lower risk of in-hospital and one-year mortality after hip fracture surgery. METHODS: Data for all patients who underwent surgery for hip fracture from January 2008 to December 2016 were extracted from the Korean National Healthcare Insurance Service database. According to mean annual case volume of surgery for hip fracture, hospitals were classified into very low (< 30 cases/year), low (30 to 50 cases/year), intermediate (50 to 100 cases/year), high (100 to 150 cases/year), or very high (> 150 cases/year) groups. The association between hospital case volume and in-hospital mortality or one-year mortality was assessed using the logistic regression model to adjust for age, sex, type of fracture, type of anaesthesia, transfusion, comorbidities, and year of surgery. RESULTS: Between January 2008 and December 2016, 269,535 patients underwent hip fracture surgery in 1,567 hospitals in Korea. Compared to hospitals with very high volume, in-hospital mortality rates were significantly higher in those with high volume (odds ratio (OR) 1.10, 95% confidence interval ((CI) 1.02 to 1.17, p = 0.011), low volume (OR 1.22, 95% CI 1.14 to 1.32, p < 0.001), and very low volume (OR 1.25, 95% CI 1.16 to 1.34, p < 0.001). Similarly, hospitals with lower case volume showed higher one-year mortality rates compared to hospitals with very high case volume (low volume group, OR 1.15, 95% CI 1.11 to 1.19, p < 0.001; very low volume group, OR 1.10, 95% CI 1.07 to 1.14, p < 0.001). CONCLUSION: Higher hospital case volume of hip fracture surgery was associated with lower in-hospital mortality and one-year mortality in a dose-response fashion. Cite this article: Bone Joint J 2020;102-B(10):1384-1391.

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.

Association between institutional case volume and mortality following thoracic aorta replacement: a nationwide Korean cohort study.

BACKGROUND: The inverse relationship between case volume and postoperative mortality following high-risk surgical procedures have been reported. Thoracic aorta surgery is associated with one of the highest postoperative mortality. The relationship between institutional case volume and postoperative mortality in patients undergoing thoracic aorta replacement surgery was evaluated. METHODS: All thoracic aorta replacement surgeries performed in Korea between 2009 and 2016 in adult patients were analyzed using an administrative database. Hospitals were divided into low (< 30 cases/year), medium (30-60 cases/year), or high (> 60 cases/year) volume centers depending on the annual average number of thoracic aorta replacement surgeries performed. The impact of case volume on in-hospital mortality was assessed using the logistic regression. RESULTS: Across 83 hospitals, 4867 cases of thoracic aorta replacement were performed. In-hospital mortality was 8.6% (191/2222), 10.7% (77/717), and 21.9% (422/1928) in high, medium, and low volume centers, respectively. The adjusted risk of in-hospital mortality was significantly higher in medium (odds ratio [OR], 1.56; 95% confidence interval [CI], 1.16-2.11, P = 0.004) and low volume centers (OR, 3.12; 95% CI, 2.54-3.85, P < 0.001) compared to high volume centers. CONCLUSIONS: Patients who had underwent thoracic aorta replacement surgery in lower volume centers had increased risk of in-hospital mortality after surgery compared to those in higher volume centers. Our results may provide the basis for minimum case volume requirement or regionalization in thoracic aorta replacement surgery for optimal patient outcome.

Prediction of anterior commissure exposure of vocal folds prior to laryngeal microscopic surgery: Parameters reflecting occipito-atlanto-axial complex extension capacity.

OBJECTIVE: The purpose of this prospective study was to identify preoperative predictors of unstable exposure of vocal folds with focus on the anterior commissure (AC) prior to Laryngeal Microscopic Surgery. METHODS AND MATERIALS: Patients were classified into four groups based on the degree of AC exposure during Laryngeal Microscopic Surgery, and for the analysis, these groups were subdivided into unstable exposure and stable exposure subgroups depending on whether external manipulation was required to achieve AC exposure. Correlation of the degree of AC exposure with demographics, physical measurements, and anatomical measurements taken using landmarks in simple radiograph were evaluated. Receiver operating characteristic curve analysis was used to determine optimal cutoff values to predict unstable AC exposure. RESULTS: Fifty-nine patients were included in the analyses. Thyroid-mandible angle (TMA) in the extended position, thyroid-mental distance (TMD) ratio, and TMA difference in the neutral and extended positions were significantly correlated with the degree of AC exposure. However, only a TMD ratio of <1.25 reliably predicted unstable AC exposure. CONCLUSIONS: TMD ratio of <1.25 reliably predicted unstable AC exposure. If there is no increase of the distance between the thyroid notch and the mental prominence (TMD) more than 25% on neck extension, the probability of getting stable exposure of the anterior commissure is low.