Pulse oximetry is used to screen for respiratory failure in dyspnea patients. However, pulse oximetry can yield false-positive results in certain situations. Unstable hemoglobinopathy is a disease in which mutations in the globin-encoding gene result in abnormal globin chain production, causing low percutaneous oxygen saturation (SpO₂) levels due to changes in hemoglobin absorbance and oxygen affinity. We identified a new family lineage of Hb Hirosaki in an adult patient with chronic obstructive pulmonary disease, dyspnea, and low SpO₂. According to our literature review, only a few cases of unstable hemoglobinopathy have been reported in adults. Most patients with unstable hemoglobinopathy are asymptomatic, and those with dyspnea often have respiratory diseases or severe anemia. To differentiate unstable hemoglobinopathy, an appropriate assessment of the discrepancy between SpO₂ values and arterial blood gas analysis results is important.

Objective Triple-vessel disease (TVD) is a well-established prognostic factor for patients with acute myocardial infarction. However, there is a paucity of literature regarding the risk factors for in-hospital death in patients with non-ST-segment elevation myocardial infarction (NSTEMI) and TVD. In this retrospective study, we examined the determinants of in-hospital death in patients with NSTEMI and TVD who underwent percutaneous coronary intervention (PCI) for culprit lesions.

Methods The primary objective of this study was to identify the factors associated with in-hospital death using a multivariate analysis. We included 253 patients with NSTEMI and TVD and divided them into a survivor group (n=239) and an in-hospital death group (n=14).

Results Systolic blood pressure (SBP) at admission was significantly higher in the survivor group than in the in-hospital death group. The estimated glomerular filtration rate (eGFR) was also higher in the survivor group than in the in-hospital death group. In the multivariate logistic regression analysis, in-hospital death was inversely associated with the SBP at admission [odds ratio (OR) 0.984, 95% confidence interval (CI) 0.970-0.999, p<0.035] and eGFR (OR 0.966, 95% CI 0.939-0.994, p=0.019) and was associated with cardiopulmonary arrest (CPA) before PCI (OR 8.448, 95% CI 1.863-38.309, p=0.006).

Conclusion In-hospital death was associated with CPA before PCI and inversely associated with the SBP at admission and eGFR in patients with NSTEMI and TVD who underwent PCI for the culprit lesion. It may be important to recognize these high-risk features in order to improve the clinical outcomes of patients with NSTEMI and TVD.

Objective The present study evaluated the usefulness of machine learning (ML) models with the coronary computed tomography imaging and clinical parameters for predicting major adverse cardiac events (MACEs).

Methods The Nationwide Gender-specific Atherosclerosis Determinants Estimation and Ischemic Cardiovascular Disease Prospective Cohort study (NADESICO) of 1,187 patients with suspected coronary artery disease 50-74 years old was used to build a MACE prediction model. The ML random forest (RF) model was compared with a logistic regression analysis. The performance of the ML model was evaluated using the area under the curve (AUC) with the 95% confidence interval (CI).

Results Among 1,178 patients from the NADESICO dataset, MACEs occurred in 103 (8.7%) patients during a median follow-up of 4.4 years. The AUC of the RF model for MACE prediction was 0.781 (95% CI: 0.670-0.870), which was significantly higher than that of the conventional logistic regression model [AUC, 0.750 (95% CI: 0.651-0.839)]. The important features in the RF model were coronary artery stenosis (CAS) at any site, CAS in the left anterior descending branch, HbA1c level, CAS in the right coronary artery, and sex. In the external validation cohort, the model accuracy of ensemble ML-RF models that were trained on and tuned using the NADESICO dataset was not similar [AUC: 0.635 (95% CI: 0.599-0.672)].

Conclusion The ML-RF model improved the long-term prediction of MACEs compared to the logistic regression model. However, the selected variables in the internal dataset were not highly predictive of the external dataset. Further investigations are required to validate the usefulness of this model.

Objective Hypouricemia, defined as a serum uric acid (SUA) level ≤2 mg/dL, could be a risk factor for death in hospitalized patients. However, how explanatory variables can explain hypouricemia as an objective variable in a logistic regression analysis remains unknown. To predict the risk factors for hypouricemia in hospitalized patients using a robust Bayesian logistic (RBL) model.

Methods This study retrospectively enrolled patients who visited Yonago Medical Center between April 2020 and March 2021. The association between potential risk factors and hypouricemia was analyzed using the RBL model in Python-modulated PyMC3. The final model was selected based on the lowest Watanabe-Akaike information criterion (WAIC).

Results Of the 618 patients, 64 (10.4%) had hypouricemia. Based on the model according to the lowest WAIC, independent risk factors for hypouricemia were febuxostat [odds ratio (OR) 5.46, 95% confidence interval (CI) 2.32-13.4], amino acids in parenteral nutrition (OR 5.19, 95% CI 1.62-15.1), TMP-SMX (OR 4.20, 95% CI 1.66-10.9), emaciation (OR 3.48, 95% CI 1.75-7.21), and serum sodium level (OR 0.90, 95% CI 0.84-0.96).

Conclusion The RBL model predicted amino acids in parenteral nutrition, TMP-SMX, emaciation, and low serum sodium levels for hypouricemia, in addition to the authentic risk factor febuxostat.

Objective Overly rapid correction of profound hyponatremia can lead to osmotic demyelination syndrome; however, the incidence of and risk factors for overly rapid correction in patients with profound hyponatremia have not been thoroughly examined. Therefore, this study examined the incidence of and risk factors for overly rapid correction in patients with profound hyponatremia.

Methods This single-center, retrospective cohort study conducted at an 865-bed teaching hospital analyzed data from 144 new inpatients with profound hyponatremia [initial serum sodium (Na⁺) level of <125 mEq/L] treated in our department between January 2014 and December 2022. Overly rapid correction was defined as serum Na⁺ correction of >10 mEq/L at 24 h. We examined the incidence of and risk factors for overly rapid correction.

Results Thirty (20.8%) patients met the overly rapid correction criteria; however, none developed osmotic demyelination syndrome. A low initial serum Na⁺ level, female sex, primary polydipsia, and low frequency of follow-up in 24 h were significant independent risk factors for overly rapid correction in the multivariable analysis (p=0.020, p=0.011, p=0.014, and p=0.025, respectively).

Conclusion Our study shows that a low initial serum Na⁺ level, female sex, primary polydipsia, and low frequency of follow-up within 24 h are associated with an increased risk for overly rapid correction of profound hyponatremia. Therefore, we suggest that physicians perform careful management when managing patients with profound hyponatremia with the risk factors for overly rapid correction identified in this study.

Objective Patients with advanced interstitial lung disease (ILD) struggle to undergo spirometry to evaluate the respiratory function. The cardiothoracic ratio (CTR) on chest radiography can potentially reflect the lung volume; however, this has not yet been fully established. This study aimed to clarify the relationship between the CTR and the respiratory function in patients with interstitial lung diseases.

Methods We reviewed 120 consecutive patients with idiopathic interstitial lung disease who were admitted to our department between April 2018 and March 2023 and who underwent chest radiography, spirometry, and echocardiography. A multiple linear regression analysis was used to identify the factors associated with the CTR. Correlations between the CTR and the respiratory or cardiac function were assessed using Pearson's correlation coefficient.

Results A multiple linear regression analysis showed the percent vital capacity (β= -0.598, p<0.001), age (β=0.405, p<0.001), and female sex (β=0.177, p=0.047) to be independently associated with the CTR, whereas no relationship was observed between the left ventricular ejection fraction, body mass index, and smoking habits. The CTR was significantly negatively correlated with the vital capacity (r=-0.490, p<0.001).

Conclusion An increased CTR might reflect a decreased vital capacity, but not a decreased cardiac function, in patients with interstitial lung diseases. Measuring the CTR can thus be beneficial for predicting progression in patients with ILD.

Objective High-quality evidence proving the superiority of hospitalist services is lacking. We developed risk-adjusted performance indicators from a multilevel prediction model using a nationwide inpatient database to evaluate hospitalist medical care for patients with aspiration pneumonia.

Methods We extracted cases diagnosed with aspiration pneumonia between 2014 and 2021 from the Diagnosis Procedure Combination (DPC) database. Hospital-level risk-adjusted performance indicators were the observed-to-expected ratio of the following outcomes using a multilevel prediction model containing both patient- and hospital-level variables: death or transfer in poor condition within 30 days (Poor outcome), in-hospital death within 30 days, and discharges within the 25th and 50th percentiles for length of stay defined by the DPC system. Using the predicted numbers of each outcome without random intercept as denominators of both indicators, the numerators of Indicator 1 were observed numbers of each outcome, while those in Indicator 2 were "smoothed" predicted numbers of outcomes estimated by the fitted model with random intercept. The ratio of the number of outcomes for each hospital to the mean number of outcomes among participating hospitals was used as a reference. We applied these indicators to Takatsuki General Hospital (TGH) as a working example.

Results A total of 526,245 patients were analyzed. Compared with Indicator 1, Indicator 2 showed greater stability in the mean ratio and bootstrapping confidence interval (CI). Indicator 2 of Poor outcome and discharges within the 25th percentile in 2017 at TGH were 1.110 (95% CI 0.784-1.375) and 1.458 (95% CI 1.272-1.597), respectively.

Conclusion Utilizing a nationwide inpatient database, we developed risk-adjusted performance indicators using a multilevel prediction model to evaluate hospitalist medical care for patients with aspiration pneumonia. Given the reliable results shown in the working example, these indicators have potential benefits for the accurate evaluation of the quality of medical care.

Downhill esophageal varices often develop because of venous hypertension caused by either superior vena cava obstruction or compression. We herein present a case of downhill esophageal varices caused by a giant goiter in a patient with postoperative Graves' disease. A 66-year-old man presented with an enlarged goiter. Gastrointestinal endoscopy revealed upper esophageal varices. This patient was successfully treated with repeated segmental embolization of the thyroid arteries that fed the goiter, followed by embolization of the inflow vein for downhill esophageal varices. Three years later, no re-enlargement of either the goiter or the appearance of downhill varices was observed. Segmental embolization therapy is thus considered to be a safe alternative for the treatment of downhill esophageal varices caused by giant goiter.

Retained placenta can lead to septic shock; however, sepsis-induced cardiomyopathy (SICM) due to retained placenta has not been reported previously. This report presents a rare case of SICM following septic shock due to retained placenta after miscarriage in a 40-year-old woman, accompanied by the "shark fin sign" on an electrocardiogram, a pattern typically linked to myocardial ischemia. She experienced ventricular tachycardia and required venoarterial extracorporeal membrane oxygenation; however, she was successfully treated. We also reviewed previous cases of shark fin sign in patients without myocardial infarction. A review showed that half of the cases experienced lethal arrhythmias, even without myocardial infarction.

Hypercalcemia is a significant complication in cancer patients, primarily caused by parathyroid hormone-related peptide (PTHrP) and, rarely, by parathyroid hormone (PTH) production from tumors. We report a case of severe hypercalcemia in a woman with uterine cancer who exhibited elevated PTH and PTHrP levels. Surgical intervention revealed dedifferentiated endometrial carcinoma. Postoperatively, PTH and PTHrP levels normalized but subsequently increased due to metastases. A molecular analysis confirmed the expression of the PTH gene and protein within the tumor, indicating ectopic PTH production. In diagnosing and treating cancers, it is necessary to consider not only PTHrP production but also ectopic PTH production.

A 37-year-old, never-smoker, pregnant woman diagnosed with Graves' disease who had stable thyroid eye disease (TED) before pregnancy presented with aggravated proptosis and eyelid swelling at 13 weeks of pregnancy. Despite the administration of local triamcinolone and 3 cycles of corticosteroid pulse therapy from 25 to 28 weeks, the patient's visual acuity decline necessitated postpartum orbital decompression surgery. Although thyroid stimulating hormone (TSH) receptor antibody levels decreased during the mid- to late term of pregnancy, the TED worsened. This finding suggests that factors other than anti-TSH receptor antibodies may have a significant effect on disease severity.

A 42-year-old woman presented with muscle weakness and hypokalemic distal renal tubular acidosis (dRTA). Investigations revealed concurrent Sjögren's syndrome (SS) and Hashimoto's thyroiditis contributing to hypokalemic dRTA. A renal biopsy revealed focal tubulointerstitial nephritis (TIN) suggestive of SS-related renal involvement, along with distinctive ischemic glomerular changes and tubular alterations consistent with hypokalemic nephropathy. Rapid improvement in tubular injury markers and hypobicarbonemia followed potassium supplementation, suggesting that hypokalemia contributed to proximal tubular injury. This case underscores the diagnostic challenge posed by the simultaneous presence of TIN and hypokalemic nephropathy, potentially masking hypokalemic nephropathy in patients with hypokalemic dRTA secondary to SS-TIN.

A 57-year-old man was diagnosed with peritoneal dialysis (PD)-associated peritonitis 2 months after surgery for tunnel infection caused by Mycobacteroides abscessus (M. abscessus). The patient was treated with multiple antibiotics, and the cell count in the PD effluent decreased. However, the patient experienced abdominal pain and developed hiccups. Computed tomography revealed an encapsulated fluid collection, indicating intra-abdominal abscess (IAA) formation. Percutaneous drainage was performed to treat IAA, and the catheter was removed. This case suggests that PD-associated peritonitis caused by M. abscessus can lead to IAA formation. If symptoms persist even after a favorable course of peritonitis, IAA should be suspected.

Tiopronin is a key drug used to treat cystinuria. A 41-year-old Japanese woman with cystinuria presented with eyelid edema and weight gain after the administration of tiopronin. Her serum albumin was 1.8 g/dL and her urinary protein level was 5.5 g/gCre. After cessation of tiopronin, she achieved remission of nephrotic syndrome (NS). Secondary NS due to tiopronin was evident based on the clinical course and laboratory values. A kidney biopsy showed membranous nephropathy (MN), and an immunofluorescence analysis revealed strong deposition of immunoglobulin G4 (IgG4). However, a previous case report of tiopronin-induced MN showed staining for IgG1 and IgG3. This case report suggests a novel etiology for tiopronin-induced MN.

Angiosarcoma is a rare malignancy that can arise from chronic pyothorax. We herein report a 75-year-old Japanese man with a history of tuberculosis who presented with left-sided chest pain that had persisted for 4 months. Chest computed tomography revealed an encapsulated left-sided pleural effusion with chest wall invasion, and histopathology confirmed angiosarcoma arising from a chronic tuberculous pyothorax. Chemotherapy with paclitaxel (80 mg/m² weekly) was ineffective and was discontinued after 3 months. Our findings emphasize that physicians should inform patients with chronic tuberculous pyothorax about malignant complications for which chest pain is the initial symptom, in addition to highlighting the need for careful follow-up.

We herein report a 64-year-old man with KRAS^G12C-mutated advanced lung adenocarcinoma previously treated with immune checkpoint inhibitors (ICIs). One month after starting second-line sotorasib treatment, the patient experienced a progressive decline in serum hemoglobin levels. Anemia was accompanied by markedly elevated serum erythropoietin levels and decreased reticulocyte levels. Bone marrow aspiration revealed pure red cell aplasia. No secondary causes other than medication use were identified. Suspected causative drugs were sotorasib and ICIs. Discontinuation of sotorasib for one week improved his anemia; therefore, the causative drug was identified as sotorasib.

A 55-year-old man presented to our hospital with idiopathic pulmonary fibrosis (IPF). He was registered with the Japan Organ Transplant Network the following year due to disease progression. Treatment with clarithromycin, ethambutol, and rifampicin for complications of Mycobacterium avium pulmonary disease was initiated, but sputum conversion could not be achieved. The administration of an amikacin liposome inhalation suspension (ALIS) resulted in sputum conversion, and single-lung transplantation was performed. ALIS therapy was continued after lung transplantation, and no M. avium disease was observed for 15 months. ALIS may cause M. avium pulmonary disease with additional indications for lung transplantation.

Anti-N-methyl-d-aspartate receptor (NMDAR) encephalitis is an autoimmune encephalitis, and 46% of women with anti-NMDAR encephalitis have tumors, of which 94% are ovarian teratomas. Patients with anti-NMDAR encephalitis rarely have extra-ovarian teratomas, particularly extra-ovarian mature cystic teratomas arising from the retroperitoneum. We herein report a 27-year-old woman who was diagnosed with anti-NMDAR encephalitis caused by a teratoma arising from the retroperitoneum. In patients with anti-NMDAR encephalitis, it is important to perform a systemic search, including for extra-ovarian teratomas. Plasma exchange significantly improved the patient's clinical symptoms.

Patient 1 (82 years old) had recurrent weakness and numbness in the left upper extremity, Patient 2 (71 years old) had transient dysarthria, and Patient 3 (70 years old) had transient apraxia of speech. Transient ischemic attack (TIA) was suspected; however, all three women had a history of head trauma before the symptom onset, and magnetic resonance imaging revealed subdural hematomas near the responsible lesions associated with sulcal hyperintensity (SHI) in the cerebral sulcus near the hematoma. Patients 1 and 2 improved spontaneously, whereas Patient 3 improved with antiseizure medication. Subdural hematomas associated with SHI may have transient focal neurological deficits that manifest through a mechanism unlike TIA.

A 58-year-old woman was admitted to our hospital with anasarca and generalized lymphadenopathy. Laboratory data showed serum creatinine 1.48 mg/dL, C-Reactive Protein 2.38 mg/dL, platelet 102,000/μL, and anti-SS-A antibodies. A lymph node biopsy revealed a regressed germinal center and hypervascularization in the interfollicular area. The patient was diagnosed with TAFRO-like symptoms occurring with Sjögren's syndrome and human T-cell leukemia virus type 1 (HTLV-1) infection, and 80 mg of methylprednisolone and tocilizumab 8 mg/kg biweekly were initiated. Her body weight decreased from 59.4 to 41 kg, and pleural effusion disappeared 8 weeks later. This case suggests that TAFRO-like symptoms may occur in patients with Sjögren's syndrome with HTLV-1 infection.

Histoplasmosis is caused by Histoplasma capsulatum and is prevalent in areas of the world where H. capsulatum is endemic. We herein report a patient diagnosed with human immunodeficiency virus-1 (HIV-1) who developed histoplasmosis from a non-H. capsulatum endemic area who experienced severe hemophagocytic syndrome due to a delayed diagnosis. The patient's symptoms emerged four years after residing in regions with a high histoplasmosis prevalence. The unrestricted administration of antifungal medication for oral candidiasis delayed the diagnosis because it improved the patient's condition. This case underscores the importance of prudent antifungal drug use in undiagnosed disseminated conditions and evaluating the travel history going back several years to facilitate a diagnosis.