Background: With the aging population and advancements in medical care worldwide, the number of older patients with end-stage kidney disease continues to rise. This study aimed to identify factors associated with osteoporosis and osteopenia in older patients undergoing incident hemodialysis and assess their impact on mortality. Methods: We analyzed a large multicenter retrospective cohort of patients aged ≥70 years undergoing incident hemodialysis to identify factors associated with osteoporosis using logistic regression analysis and to assess the association of death with osteoporosis and osteopenia using Cox multivariable analysis. Results: Among 710 patients, 39.0% and 19.6% had osteoporosis and osteopenia, respectively. Osteoporosis was significantly associated with female sex, a history of fractures, and the absence of phosphate binder use. During a median follow-up of 36.8 months, 348 participants (58.8%) died. Mortality rates were the highest in the osteoporosis group (79.8%), followed by the osteopenia (77.2%) and normal bone mineral density (BMD) groups (35.2%). Cox regression analysis revealed that even after adjusting for covariates, the osteoporosis group was significantly associated with a higher mortality risk than the normal BMD group. Osteoporosis at the start of hemodialysis was significantly associated with higher mortality. Conclusion We should consider the importance of bone health in patients undergoing incident hemodialysis and pay attention to the use of phosphate binders and fracture prevention.

Background: Obesity is a well-known risk factor for chronic kidney disease and its progression. However, the impact of obesity on the renal function of the elderly population is uncertain. We investigated the association between obesity and renal outcomes in the elderly. Methods: We analyzed 130,504 participants from the Korean National Health Insurance Service-Senior cohort. Obesity was classified according to body mass index (BMI), sex-specific waist circumference (WC), and the presence of metabolic syndrome. The primary outcome was renal function decline, defined as a decline in the estimated glomerular filtration rate (eGFR) of at least 50% from baseline or new-onset end-stage renal disease. Results: During a follow-up period of 559,531.1 person-years (median, 4.3 years), 2,486 participants (19.0%; incidence rate of 4.44 per 1,000 person-years) showed renal function decline. A multivariate Cox proportional hazards model revealed that BMI/WC was not associated with renal function decline. However, the group with metabolic syndrome had a significantly increased risk of renal function decline compared to the group without metabolic syndrome (adjusted hazard ratio [HR], 1.24; 95% confidence interval [CI], 1.13–1.36). Compared with the non-metabolic syndrome group, the adjusted HRs (95% CI) for participants with one through five components were 0.96 (0.84–1.11), 1.10 (0.96–1.27), 1.24 (1.06–1.45), 1.37 (1.12–1.66), and 1.99 (1.42–2.79), respectively (p for trend < 0.001). Conclusion In elderly Korean adults, metabolic syndrome and the number of its components were associated with a higher risk of renal function decline, but BMI or WC was not significant.

Early mortality following hemodialysis initiation hinders survival improvement in older patients. This study aimed to develop a clinical risk model for predicting 6-month mortality after dialysis initiation in older Korean hemodialysis patients. Methods: We analyzed data from incident hemodialysis patients aged >70 years from the Korean Society of Geriatric Nephrology (KSGN) database. A prediction model was developed using multivariate logistic regression analysis and externally validated with independent datasets. Results: Among 1,751 incident hemodialysis patients, the 6-month mortality rate was 15.5%. Using multivariate logistic analysis, we constructed the KSGN score as an independent risk factor for 6-month mortality, and its components and score are as follows: old age at dialysis initiation (≥85 years, score 2); hypertension and renovascular disease as a primary etiology of end-stage kidney disease (ESKD) (score 1); malignancy history (yes, score 1); low serum albumin (<3.5 g/dL, score 1); hypertension treatment (yes, score –1); prepared vascular access on maintenance dialysis (arteriovenous fistula/arteriovenous graft, score –3). In the development cohort, the area under the curve (AUC) for the KSGN score was significantly higher than the Alberta Wick’s score (0.707 vs. 0.683, p = 0.001). In the validation cohort, the KSGN score’s performance was comparable to existing models. Conclusion: The KSGN score may be a valuable tool for predicting early mortality after dialysis initiation in older patients with ESKD, aiding in decision-making and management regarding dialysis initiation.

The prevalence of dementia is 2- to 7-fold higher among patients with end-stage kidney disease (ESKD) than among the general population; however, its clinical implications in this population remain unclear. Therefore, this study aimed to determine whether comorbid dementia increases mortality among older patients with ESKD undergoing newly initiated hemodialysis. Methods: We analyzed data from the Korean Society of Geriatric Nephrology retrospective cohort, which included 2,736 older ESKD patients (≥70 years old) who started hemodialysis between 2010 and 2017. Kaplan-Meier survival and Cox regression analyses were used to examine all-cause mortality between the patients with and without dementia in this cohort. Results: Of the 2,406 included patients, 8.3% had dementia at the initiation of dialysis; these patients were older (79.6 ± 6.0 years) than patients without dementia (77.7 ± 5.5 years) and included more women (male:female, 89:111). Pre-ESKD diagnosis of dementia was associated with an increased risk of overall mortality (hazard ratio, 1.503; p < 0.001), and this association remained consistent after multivariate adjustment (hazard ratio, 1.268; p = 0.009). In subgroup analysis, prevalent dementia was associated with mortality following dialysis initiation in female patients, those aged <85 years, those with no history of cerebrovascular accidents or severe behavioral disorders, those not residing in nursing facilities, and those with no or short-term hospitalization. Conclusion: A pre-ESKD diagnosis of dementia is associated with mortality following dialysis initiation in older Korean population. In older patients with ESKD, cognitive assessment at dialysis initiation is necessary.

Purpose: This study investigated the causative microorganisms, antibiotic susceptibility, and risk factors of infectious keratitis over the past 10 years. Methods: Data from patients with infectious keratitis who underwent microbial culture tests from 2012 to 2021, obtained from anonymized data systems, were analyzed. Microbial culture results and antibiotic susceptibility profiles were examined. A retrospective analysis of the medical records of patients with infectious keratitis during the same period was conducted to investigate the clinical characteristics and risk factors. Results: Data from 1,837 cases of infectious keratitis were extracted from anonymized records. The culture positive rate among patients was 46.0% (1,137/2,474), with coagulase-negative Staphylococcus (CoNS) being the most common causative organism (27.8%). Increased resistance to cefazolin and cefotaxime was observed in gram-negative bacteria, while there were no significant temporal changes in quinolone resistance in gram-positive or negative bacteria. A retrospective medical record analysis of 288 cases revealed that older patients, as well as those with an initial corrected visual acuity < 0.1, a history of ocular surgery, pre-existing ocular conditions, prior steroid eye drops, or glaucoma eye drops, had significantly higher rates of culture positivity. Multivariate analysis identified risk factors for severe keratitis requiring surgical intervention as a symptom-to-presentation period of 7 days or longer (p = 0.048) and pre-existing ocular conditions (p = 0.040). Conclusions CoNS was the most common microorganism causing infectious keratitis over the past decade. There has been an increase in resistance to cephalosporin antibiotics among gram-negative bacteria. Patients with pre-existing ocular conditions may require surgical intervention, so infectious keratitis in these patients requires greater attention.

Background/Aims: A full colonoscopy is currently required in children and adolescents with colorectal polyps, because of their potential of neoplastic transformation and complications such as intussusception. We aimed to analyze the associations of polyp characteristics in children and adolescents with colorectal polyps. Based on these findings, we also aimed to reevaluate the necessity of conducting a full colonoscopy. Methods: Pediatric patients <18 years of age who had undergone a colonoscopic polypectomy and those with <5 colorectal polyps were included in this multicenter, retrospective study. Baseline clinicodemographics, colonoscopic and histologic findings were investigated. Results: A total of 91 patients were included. Multivariate logistic regression analysis showed that polyp size was the only factor associated with the presence of any polyps located proximal to the splenic flexure (odds ratio [OR], 2.25; 95% confidence interval [CI], 1.28 to 4.28; p=0.007). Furthermore, polyp location proximal to the splenic flexure and sessile morphology were associated with the presence of any adenomatous polyp (OR, 8.51; 95% CI, 1.43 to 68.65; p=0.023; OR, 18.41; 95% CI, 3.45 to 173.81; p=0.002, respectively). Conclusions In children and adolescents presenting with <5 colorectal polyps, polyp size and the presence of any adenomatous polyp were positively associated with polyp location proximal to the splenic flexure. This finding supports the necessity of a full colonoscopic exam in pediatric patients with colorectal polyps for the detection of polyps before the occurrence of complications such as intussusception or neoplastic transformation.

Objectives: Although medical artificial intelligence (AI) systems that assist healthcare professionals in critical care settings are expected to improve healthcare, skepticism exists regarding whether their potential has been fully actualized. Therefore, we aimed to conduct a qualitative study with physicians and nurses to understand their needs, expectations, and concerns regarding medical AI; explore their expected responses to recommendations by medical AI that contradicted their judgments; and derive strategies to implement medical AI in practice successfully. Methods: Semi-structured interviews were conducted with 15 healthcare professionals working in the emergency room and intensive care unit in a tertiary teaching hospital in Seoul. The data were interpreted using summative content analysis. In total, 26 medical AI topics were extracted from the interviews. Eight were related to treatment recommendation, seven were related to diagnosis prediction, and seven were related to process improvement. Results: While the participants expressed expectations that medical AI could enhance their patients’ outcomes, increase work efficiency, and reduce hospital operating costs, they also mentioned concerns regarding distortions in the workflow, deskilling, alert fatigue, and unsophisticated algorithms. If medical AI decisions contradicted their judgment, most participants would consult other medical staff and thereafter reconsider their initial judgment. Conclusions Healthcare professionals wanted to use medical AI in practice and emphasized that artificial intelligence systems should be trustworthy from the standpoint of healthcare professionals. They also highlighted the importance of alert fatigue management and the integration of AI systems into the workflow.

Tixagevimab/cilgavimab is a monoclonal antibody used to prevent coronavirus disease 2019 among immunocompromised hosts and maintained neutralizing activity against early omicron variants. Omicron BN.1 became a dominant circulating strain in Korea early 2023, but its susceptibility to tixagevimab/cilgavimab is unclear. We conducted plaque reduction neutralization test (PRNT) against BN.1 in a prospective cohort (14 patients and 30 specimens). BN.1 PRNT was conducted for one- and three-months after tixagevimab/ cilgavimab administration and the average PRNT ND 50 of each point was lower than the positive cut-off value of 20 (12.9 ± 4.5 and 13.2 ± 4.2, respectively, P = 0.825). In the paired analyses, tixagevimab/cilgavimab-administered sera could not actively neutralize BN.1 (PRNT ND 50 11.5 ± 2.9, P = 0.001), compared with the reserved activity against BA.5 (ND 50 310.5 ± 180.4). Unlike virus-like particle assay, tixagevimab/cilgavimab was not active against BN.1 in neutralizing assay, and would not be effective in the present predominance of BA.2.75 sublineages.

Purpose: To introduce an intuitive method for measuring conjunctival microvascular blood flow velocity by imaging bulbar conjunctival microvessels using a slit-lamp biomicroscope equipped with a zoom lens and an ultra-high-speed camera. Methods: After obtaining consent from 10 patients (1 male, 9 females) who visited Yeouido St. Mary’s Hospital from August 21, 2020, to June 12, 2021, the patients were examined under a slit lamp microscope equipped with an ultra-high-speed camera and zoom lens. The blood flow in the conjunctival microvessels was photographed. The captured images were analyzed with ImageJ software to measure the blood flow velocity in the conjunctival microvessels, and we investigated whether the blood flow velocity correlated with the vessel diameter and age. Results: The median age of the subjects was 49.0 years. The mean conjunctival blood flow velocity in 53 microvessels was 0.786 ± 0.468 mm/s. The median conjunctival microvascular diameter was 7.06 μm (interquartile range 5.84 to 9.23 μm). The conjunctival microvascular diameter and blood flow velocity were not significantly correlated (Spearman’s p = 0.177), and the subjects’ age and conjunctival microvascular blood flow velocity were also not correlated (Spearman’s p = 0.669). Conclusions In this study, the blood flow velocity in the bulbar conjunctival microvessels could be measured easily by means of image analysis using a slit-lamp microscope equipped with an ultra-high-speed camera with a zoom lens.

Clearance of a difficult biliary stone can be obtained using various interventional techniques such as endoscopic sphincterotomy followed by endoscopic papillary large balloon dilation, mechanical lithotripsy, peroral cholangioscopy-assisted intraductal electrohydraulic/laser lithotripsy, temporary plastic stent insertion, percutaneous transhepatic cholangioscopy-guided lithotripsy, and extracorporeal shock wave lithotripsy. We hereby describe the successful endoscopic treatment using various currently available interventional techniques in a case with multiple difficult common bile duct stones. Furthermore, we discuss the countermeasures to overcome the hurdles of each procedure.