Bisphosphonates are commonly used to treat osteoporosis. While renal toxicity is common with pamidronate and zoledronate, few ibandronate-related cases are reported. We describe a rare case of ibandronate-associated nephrotoxicity. An 88-year-old woman was admitted for edema. She had been receiving intravenous ibandronate treatment for postmenopausal osteoporosis and had no other diagnosed diseases. She was presented with proteinuria, hypoalbuminemia (1.9 g/dL), and an elevated serum creatinine level (1.8 mg/dL). Renal biopsy revealed podocyte disease, favoring a diagnosis of focal segmental glomerulosclerosis. She was treated with diuretics, tacrolimus, and fimasartan. Steroids were avoided due to severe osteoporosis. Three months later, the edema had subsided and the laboratory findings had improved (serum albumin 3.5 g/dL, serum creatinine 0.97 mg/dL). This case emphasizes the importance of careful monitoring of proteinuria and renal function during ibandronate treatment. In older adult patients, kidney biopsy and immunosuppressive treatment may be considered based on physical activity and underlying diseases.

Background: Limited data are available on the mortality rates of patients receiving extracorporeal membrane oxygenation (ECMO) support for coronavirus disease 2019 (COVID-19). We aimed to analyze the relationship between COVID-19 and clinical outcomes for patients receiving ECMO. Methods: We retrospectively investigated patients with COVID-19 pneumonia requiring ECMO in 19 hospitals across Korea from January 1, 2020 to August 31, 2021. The primary outcome was the 90-day mortality after ECMO initiation. We performed multivariate analysis using a logistic regression model to estimate the odds ratio (OR) of 90-day mortality. Survival differences were analyzed using the Kaplan–Meier (KM) method. Results: Of 127 patients with COVID-19 pneumonia who received ECMO, 70 patients (55.1%) died within 90 days of ECMO initiation. The median age was 64 years, and 63% of patients were male. The incidence of ECMO was increased with age but was decreased after 70 years of age. However, the survival rate was decreased linearly with age. In multivariate analysis, age (OR, 1.048; 95% confidence interval [CI], 1.010–1.089; P = 0.014) and receipt of continuous renal replacement therapy (CRRT) (OR, 3.069; 95% CI, 1.312–7.180; P = 0.010) were significantly associated with an increased risk of 90-day mortality. KM curves showed significant differences in survival between groups according to age (65 years) (log-rank P = 0.021) and receipt of CRRT (log-rank P = 0.004). Conclusion Older age and receipt of CRRT were associated with higher mortality rates among patients with COVID-19 who received ECMO.

Background: Little is known regarding the effects of continuous positive airway pressure (CPAP) on sleep misperception in obstructive sleep apnea (OSA). Methods: Sleep state perception was measured by subtracting the objective total sleep time from the subjective sleep duration. Sleep underestimation and overestimation were defined as ± 60 minutes sleep perception. Insomnia and depressive symptoms were assessed using questionnaires. Finally, nonparametric statistical analyses were performed. Results: Of the 339 patients with OSA included in the study, 90 (26.5%) and 45 (13.3%) showed sleep underestimation and overestimation, respectively. Overall, a significant underestimation of sleep was noted during CPAP titration comparing to a diagnostic PSG (P < 0.001). OSA patients with insomnia or depressive symptoms did not show any changes in sleep perception between diagnostic and CPAP titration studies, whereas those without insomnia or depressed mood showed significantly underestimated sleep duration during CPAP titration. Patients with OSA and either underestimated or overestimated misperception showed perceptual improvements during CPAP titration regardless of the presence of insomnia or depressive symptoms. However, of 204 patients with normal sleep perception, 138 (67.6%) and 10 (4.9%) had underestimation and overestimation of sleep during CPAP titration. Conclusion CPAP titration may improve sleep perception with moderate to severe OSA who have sleep misperception. However, CPAP titration may result in sleep misperception especially underestimation of sleep in those who have normal sleep perception.

Background: There is insufficient data on the benefits of empiric antibiotic combinations for hospital-acquired pneumonia (HAP). We aimed to investigate whether empiric antipseudomonal combination therapy with fluoroquinolones decreases mortality in patients with HAP. Methods: This multicenter, retrospective cohort study included adult patients admitted to 16 tertiary and general hospitals in Korea between January 1 and December 31, 2019.Patients with risk factors for combination therapy were divided into anti-pseudomonal non-carbapenem β-lactam monotherapy and fluoroquinolone combination therapy groups.Primary outcome was 30-day mortality. Propensity score matching (PSM) was used to reduce selection bias. Results: In total, 631 patients with HAP were enrolled. Monotherapy was prescribed in 54.7% (n = 345) of the patients, and combination therapy was prescribed in 45.3% (n = 286).There was no significant difference in 30-day mortality between the two groups (16.8% vs.18.2%, P = 0.729) or even after the PSM (17.5% vs. 18.2%, P = 0.913). After the PSM, adjusted hazard ratio for 30-day mortality from the combination therapy was 1.646 (95% confidence interval, 0.782–3.461; P = 0.189) in the Cox proportional hazards model. Moreover, there was no significant difference in the appropriateness of initial empiric antibiotics between the two groups (55.0% vs. 56.8%, P = 0.898). The proportion of multidrug-resistant (MDR) pathogens was high in both groups. Conclusion Empiric anti-pseudomonal fluoroquinolone combination therapy showed no survival benefit compared to β-lactam monotherapy in patients with HAP. Caution is needed regarding the routine combination of fluoroquinolones in the empiric treatment of HAP patients with a high risk of MDR.

Background/Aims: Most studies on hospital-acquired pneumonia (HAP) have been conducted in intensive care unit (ICU) settings. This study aimed to investigate the microbiological and clinical characteristics of non-ICU-acquired pneumonia (NIAP) and to identify the factors affecting clinical outcomes in Korea. Methods: This multicenter retrospective cohort study was conducted in patients admitted to 13 tertiary hospitals between July 1, 2019 and December 31, 2019. Patients diagnosed with NIAP were included in this study. To assess the prognostic factors of NIAP, the study population was classified into treatment success and failure groups. Results: Of 526 patients with HAP, 379 were diagnosed with NIAP. Overall, the identified causative pathogen rate was 34.6% in the study population. Among the isolated organisms (n = 113), gram-negative bacilli were common pathogens (n = 91), such as Pseudomonas aeruginosa (n = 25), Acinetobacter baumannii (n = 23), and Klebsiella pneumoniae (n = 21). The multidrug resistance rates of A. baumannii, P. aeruginosa, and K. pneumoniae were 91.3%, 76.0%, and 57.1%, respectively. Treatment failure was significantly associated with K. pneumoniae (odds ratio [OR], 3.50; 95% confidence interval [CI], 1.35 to 9.05; p = 0.010), respiratory viruses (OR, 3.81; 95% CI, 1.34 to 10.82; p = 0.012), hematological malignancies (OR, 3.54; 95% CI, 1.57 to 8.00; p = 0.002), and adjunctive corticosteroid treatment (OR, 2.40; 95% CI, 1.27 to 4.52; p = 0.007). Conclusions The causative pathogens of NIAP in Korea are predominantly gram-negative bacilli with a high rate of multidrug resistance. These were not different from the common pathogens of ICU-acquired pneumonia.

Background: and Purpose To identify sex differences in daytime sleepiness associated with apnea severity and periodic limb movements during sleep (PLMS) in subjects with obstructive sleep apnea (OSA). Methods: This study used the Epworth Sleepiness Scale (ESS), Beck Depression Inventory (BDI), and Sleep Hygiene Index (SHI) in logistic regression analyses with interaction terms. Severe OSA, excessive daytime sleepiness (EDS), and PLMS were defined as an apnea-hypopnea index of ≥30, an ESS score of ≥11, and a periodic limb movements index of >15, respectively. Results: The 1,624 subjects with OSA (males, 79.1%) comprised 45.3%, 38.2%, and 16.4% with severe OSA, EDS, and PLMS, respectively. Multiple logistic regression without interaction terms showed that sex, severe OSA, and PLMS were not significantly associated with EDS. However, significant interactions were noted between sex and severe OSA and PLMS in EDS in both crude and adjusted models (all p values<0.05). In the adjusted model, severe OSA was associated with EDS in males (p=0.009) but not in females. PLMS were more likely to be associated with EDS in females (p=0.013), whereas PLMS were less likely to be associated with EDS in males (p=0.041). The models were adjusted by the BDI score, SHI, and presence of medical comorbidities. Conclusions There are significant sex differences in subjective daytime sleepiness in subjects with severe OSA and PLMS. Severe OSA and PLMS may influence daytime sleepiness more in males and females, respectively.

The purpose of this study was to evaluate clinical characteristics and treatment outcome of patients with head and neck squamous cell carcinoma of unknown primary (HNSCCUP), treated according to the method of our hospital. Six patients with histopathologically and radiologically confirmed HNSCCUP January 2010-December 2016 were enrolled in this study. All patients underwent radical neck dissection involving level I-V, bilateral tonsillectomy, and diagnostic esophagoscopy and postoperative radiotherapy (RT), with or without concurrent chemotherapy. There were no major complications resulting from surgical intervention. Duration of follow-up was 56.3±20.2 months (range, 28-82 months). There was no recurrence or late detection of primary site of HNSCCUP. All patients with HNSCCUP except one were alive, at the time of the last follow-up. The other patient had no recurrence of HNSCCUP, but died of colon cancer at 58 months postoperatively. We have successfully treated patients with HNSCCUP by performing radical neck dissection, bilateral tonsillectomy, and diagnostic esophagoscopy and postoperative RT with concurrent chemotherapy, and recommend using this method as the main treatment method.

Background/Aims: Nonalcoholic fatty liver disease (NAFLD) is closely related to gut-microbiome. There is a paucity of research on which strains of gut microbiota affect the progression of NAFLD. This study explored the NAFLD-associated microbiome in humans and the role of Lactobacillus in the progression of NAFLD in mice. Methods: The gut microbiome was analyzed via next-generation sequencing in healthy people (n=37) and NAFLD patients with elevated liver enzymes (n=57). Six-week-old male C57BL/6J mice were separated into six groups (n=10 per group; normal, Western, and four Western diet + strains [109 colony-forming units/g for 8 weeks; L. acidophilus, L. fermentum, L. paracasei, and L. plantarum]). Liver/body weight ratio, liver pathology, serum analysis, and metagenomics in the mice were examined. Results: Compared to healthy subjects (1.6±4.3), NAFLD patients showed an elevated Firmicutes/Bacteroidetes ratio (25.0±29.0) and a reduced composition of Akkermansia and L. murinus (P<0.05). In the animal experiment, L. acidophilus group was associated with a significant reduction in liver/body weight ratio (5.5±0.4) compared to the Western group (6.2±0.6) (P<0.05). L. acidophilus (41.0±8.6), L. fermentum (44.3±12.6), and L. plantarum (39.0±7.6) groups showed decreased cholesterol levels compared to the Western group (85.7±8.6) (P<0.05). In comparison of steatosis, L. acidophilus (1.9±0.6), L. plantarum (2.4±0.7), and L. paracasei (2.0±0.9) groups showed significant improvement of steatosis compared to the Western group (2.6±0.5) (P<0.05). Conclusions Ingestion of Lactobacillus, such as L. acidophilus, L. fermentum, and L. plantarum, ameliorates the progression of nonalcoholic steatosis by lowering cholesterol. The use of Lactobacillus can be considered as a useful strategy for the treatment of NAFLD.

Background: Hospital-acquired pneumonia (HAP) and ventilator-associated pneumonia (VAP) are significant public health issues in the world, but the epidemiological data pertaining to HAP/VAP is limited in Korea. The objective of this study was to investigate the characteristics, management, and clinical outcomes of HAP/VAP in Korea. Methods: This study is a multicenter retrospective cohort study. In total, 206,372 adult patients, who were hospitalized at one of the 13 participating tertiary hospitals in Korea, were screened for eligibility during the six-month study period. Among them, we included patients who were diagnosed with HAP/VAP based on the Infectious Diseases Society of America (IDSA)/American Thoracic Society (ATS) definition for HAP/VAP. Results: Using the IDSA/ATS diagnostic criteria, 526 patients were identified as HAP/VAP patients. Among them, 27.9% were diagnosed at the intensive care unit (ICU). The cohort of patients had a median age of 71.0 (range from 62.0 to 79.0) years. Most of the patients had a high risk of aspiration (63.3%). The pathogen involved was identified in 211 patients (40.1%). Furthermore, multidrug resistant (MDR) pathogens were isolated in 138 patients; the most common MDR pathogen was Acinetobacter baumannii. During hospitalization, 107 patients with HAP (28.2%) had to be admitted to the ICU for additional care. The hospital mortality rate was 28.1% in the cohort of this study. Among the 378 patients who survived, 54.2% were discharged and sent back home, while 45.8% were transferred to other hospitals or facilities. Conclusion This study found that the prevalence of HAP/VAP in adult hospitalized patients in Korea was 2.54/1,000 patients. In tertiary hospitals in Korea, patients with HAP/VAP were elderly and had a risk of aspiration, so they were often referred to step-down centers.