Citations

Background: Dofetilide and sotalol are potassium channel antagonists that require inpatient QTc monitoring during initiation, due to increased risk of fatal arrhythmias. Elderly patients are especially subject to an increased risk of fatal arrhythmias due to polypharmacy, comorbidities, and physiologic cardiac changes with aging. This study will describe the tolerability and risk factors associated with the initiation of sotalol or dofetilide in patients ≥80 years of age. Methodology: This is a multicenter, retrospective, descriptive study of patients ≥80 years old who were initiated on either dofetilide or sotalol between May 8, 2018 and July 31, 2021 at institutions within the Mayo Clinic Health System. The percentage of patients who received nonpackage insert recommended doses was identified. Incidence of and reasons for dose reductions or discontinuations due to safety-related events or clinical concerns during the initial loading period were collected. Results: The final analysis included 104 patients. The majority of patients (75%) received nonstandard initial doses of dofetilide or sotalol based on baseline estimated creatinine clearance or QTc. Overall, 39% ( N = 41) of patients experienced a dose reduction or discontinuation due to a safety-related event or concern. Patients who received nonstandard initial doses of dofetilide or sotalol had 4.7 times greater odds of experiencing a safety-related event requiring dose reduction or discontinuation. Conclusion: Following package insert dosing in elderly patients increases safety and tolerability relative to more aggressive dosing of dofetilide or sotalol.

The NCCN Guidelines for Merkel Cell Carcinoma (MCC) provide recommendations for diagnostic workup, clinical stage, and treatment options for patients. The panel meets annually to discuss updates to the guidelines based on comments from expert review from panel members, institutional review, as well as submissions from within NCCN and external organizations. These NCCN Guidelines Insights focus on the introduction of a new page for locally advanced disease in the setting of clinical node negative status, entitled “Clinical N0 Disease, Locally Advanced MCC.” This new algorithm page addresses locally advanced disease, and the panel clarifies the meaning behind the term “nonsurgical” by further defining locally advanced disease. In addition, the guideline includes the management of in-transit disease and updates to the systemic therapy options.

OBJECTIVES: Systemic thrombolysis improves outcomes in patients with pulmonary embolism (PE) but is associated with the risk of hemorrhage. The data on efficacy and safety of reduced-dose alteplase are limited. The study objective was to compare the characteristics, outcomes, and complications of patients with PE treated with full- or reduced-dose alteplase regimens. DESIGN: Multicenter retrospective observational study. SETTING: Tertiary care hospital and 15 community and academic centers of a large healthcare system. PATIENTS: Hospitalized patients with PE treated with systemic alteplase. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Pre- and post-alteplase hemodynamic and respiratory variables, patient outcomes, and complications were compared. Propensity score (PS) weighting was used to adjust for imbalances of baseline characteristics between reduced- and full-dose patients. Separate analyses were performed using the unweighted and weighted cohorts. Ninety-eight patients were treated with full-dose (100 mg) and 186 with reduced-dose (50 mg) regimens. Following alteplase, significant improvements in shock index, blood pressure, heart rate, respiratory rate, and supplemental oxygen requirements were observed in both groups. Hemorrhagic complications were lower with the reduced-dose compared with the full-dose regimen (13% vs. 24.5%, p = 0.014), and most were minor. Major extracranial hemorrhage occurred in 1.1% versus 6.1%, respectively (p = 0.022). Complications were associated with supratherapeutic levels of heparin anticoagulation in 37.5% of cases and invasive procedures in 31.3% of cases. The differences in complications persisted after PS weighting (15.4% vs. 24.7%, p = 0.12 and 1.3% vs. 7.1%, p = 0.067), but did not reach statistical significance. There were no significant differences in mortality, discharge destination, ICU or hospital length of stay, or readmission after PS weighting. CONCLUSIONS: In a retrospective, PS-weighted observational study, when compared with the full-dose, reduced-dose alteplase results in similar outcomes but fewer hemorrhagic complications. Avoidance of excessive levels of anticoagulation or invasive procedures should be considered to further reduce complications.

Abstract Background Although response in pediatric low-grade glioma (pLGG) includes volumetric assessment, more simplified 2D-based methods are often used in clinical trials. The study’s purpose was to compare volumetric to 2D methods. Methods An expert neuroradiologist performed solid and whole tumor (including cyst and edema) volumetric measurements on MR images using a PACS-based manual segmentation tool in 43 pLGG participants (213 total follow-up images) from the Pacific Pediatric Neuro-Oncology Consortium (PNOC-001) trial. Classification based on changes in volumetric and 2D measurements of solid tumor were compared to neuroradiologist visual response assessment using the Brain Tumor Reporting and Data System (BT-RADS) criteria for a subset of 65 images using receiver operating characteristic (ROC) analysis. Longitudinal modeling of solid tumor volume was used to predict BT-RADS classification in 54 of the 65 images. Results There was a significant difference in ROC area under the curve between 3D solid tumor volume and 2D area (0.96 vs 0.78, P = .005) and between 3D solid and 3D whole volume (0.96 vs 0.84, P = .006) when classifying BT-RADS progressive disease (PD). Thresholds of 15–25% increase in 3D solid tumor volume had an 80% sensitivity in classifying BT-RADS PD included in their 95% confidence intervals. The longitudinal model of solid volume response had a sensitivity of 82% and a positive predictive value of 67% for detecting BT-RADS PD. Conclusions Volumetric analysis of solid tumor was significantly better than 2D measurements in classifying tumor progression as determined by BT-RADS criteria and will enable more comprehensive clinical management.

Introduction: Exposure to high altitude results in hypobaric hypoxia, leading to physiological changes in the cardiovascular system that may result in dyspnea. Hypoxic simulation testing (HSTs) simulates changes in physiology that occur at a specific altitude. Hypothesis: The use of transthoracic echocardiography (TTE) during HST can detect the raise in right-sided pressures revealing underlying causes of high-altitude dyspnea. Methods: We performed a prospective observational study of consecutive patients with unexplained dyspnea at high altitude who were referred to an aerospace medicine program at a single institution between August 2021 and March 2023. Reduced FiO 2 was administered for 20 minutes to simulate altitude levels specific to patients’ history. TTE images were obtained at baseline and during peak hypoxia to evaluate right ventricular (RV) function, RV systolic pressure, and any possible shunts. Result: The study included 27 patients, with a mean age of 64.7 ±14.4 years and 14 (51.9%) females. No significant abnormalities were seen on baseline TTE and no significant differences in blood pressure and heart rate between baseline and hypoxia simulation were detected. Notably, RV systolic pressure increased at peak hypoxia, while RV systolic function declined as shown by a decrease in S’ wave and TAPSE ( Figure 1 ). Additionally, right to left shunts were present in 19 (70.4%) patients. Of these, four patients (21.1%) had shunts present at baseline with no changes at peak hypoxia, while the severity of shunts increased at peak hypoxia in eight cases (42.1%) and the shunts were only evident during hypoxia in seven patients (36.8%). Conclusion: TTE during HST provides valuable information by revealing the presence of symptomatic, sustained shunts and confirming the decline in RV hemodynamics explaining dyspnea at altitude. Further studies are necessary to establish the optimal clinical role of this physiologic method.

IMPORTANCE: Meropenem dosing is typically guided by creatinine-based estimated glomerular filtration rate (eGFR), but creatinine is a suboptimal GFR marker in the critically ill. OBJECTIVES: This study aimed to develop and qualify a population pharmacokinetic model for meropenem in critically ill adults and to determine which eGFR equation based on creatinine, cystatin C, or both biomarkers best improves model performance. DESIGN, SETTING, AND PARTICIPANTS: This single-center study evaluated adults hospitalized in an ICU who received IV meropenem from 2018 to 2022. Patients were excluded if they had acute kidney injury, were on kidney replacement therapy, or were treated with extracorporeal membrane oxygenation. Two cohorts were used for population pharmacokinetic modeling: a richly sampled development cohort (n = 19) and an opportunistically sampled qualification cohort (n = 32). MAIN OUTCOMES AND MEASURES: A nonlinear mixed-effects model was developed using parametric methods to estimate meropenem serum concentrations. RESULTS: The best-fit structural model in the richly sampled development cohort was a two-compartment model with first-order elimination. The final model included time-dependent weight normalized to a 70-kg adult as a covariate for volume of distribution (Vd) and time-dependent eGFR for clearance. Among the eGFR equations evaluated, eGFR based on creatinine and cystatin C expressed in mL/min best-predicted meropenem clearance. The mean (se) Vd in the final model was 18.2 (3.5) liters and clearance was 11.5 (1.3) L/hr. Using the development cohort as the Bayesian prior, the opportunistically sampled cohort demonstrated good accuracy and low bias. CONCLUSIONS AND RELEVANCE: Contemporary eGFR equations that use both creatinine and cystatin C improved meropenem population pharmacokinetic model performance compared with creatinine-only or cystatin C-only eGFR equations in adult critically ill patients.