Single Intravenous Dose Dalbavancin Pathway for the Treatment of Acute Bacterial Skin and Skin Structure Infections: Considerations for Emergency Department Implementation and Cost Savings.

BACKGROUND: A pathway for the treatment of acute bacterial skin and skin structure infections (ABSSSI) with a single intravenous (IV) dose of dalbavancin was previously shown to reduce hospital admissions and shorten inpatient length of stay (LOS). OBJECTIVES: To describe pathway implementation at the emergency department (ED) and evaluate cost-effectiveness of a single-dose dalbavancin administered to ED patients who would otherwise be hospitalized to receive usual care with multidose IV antibiotics. METHODS: The dalbavancin pathway was previously implemented at 11 U.S. EDs (doi:10.1111/acem.14258). Patients with ABSSSI, without an unstable comorbidity or infection complication requiring complex management, were treated with a single dose of dalbavancin. At the emergency physicians' discretion, patients were either discharged and received outpatient follow-up or were hospitalized for continued management. A decision analytic cost-effectiveness model was developed from the U.S. healthcare's perspective to evaluate costs associated with the dalbavancin pathway compared with inpatient usual care. Costs (2021 USD) were modeled over a 14-day horizon and included ED visits, drug costs, inpatient stay, and physician visits. One-way and probabilistic sensitivity analyses examined input parameter uncertainty. RESULTS: Driven largely by the per diem inpatient cost and LOS for usual care, the dalbavancin pathway was associated with savings of $5133.20 per patient and $1211.57 per hospitalization day avoided, compared with inpatient usual care. The results remained robust in sensitivity and scenario analyses. CONCLUSION: The new single-dose dalbavancin ED pathway for ABSSSI treatment, which was previously implemented at 11 U.S. EDs, offers robust cost savings compared to inpatient usual care.

Obesity alters oestrogen metabolism and contributes to pulmonary arterial hypertension.

Obesity is a common comorbidity for pulmonary arterial hypertension (PAH). Additionally, oestrogen and its metabolites are risk factors for the development of PAH. Visceral adipose tissue (VAT) is a major site of oestrogen production; however, the influence of obesity-induced changes in oestrogen synthesis and metabolism on the development of PAH is unclear. To address this we investigated the effects of inhibiting oestrogen synthesis and metabolism on the development of pulmonary hypertension in male and female obese mice.We depleted endogenous oestrogen in leptin-deficient (ob/ob) mice with the oestrogen inhibitor anastrozole (ANA) and determined the effects on the development of pulmonary hypertension, plasma oestradiol and urinary 16α-hydroxyestrone (16αOHE1). Oestrogen metabolism through cytochrome P450 1B1 (CYP1B1) was inhibited with 2,2',4,6'-tetramethoxystilbene (TMS).ob/ob mice spontaneously develop pulmonary hypertension, pulmonary vascular remodelling and increased reactive oxygen species production in the lung; these effects were attenuated by ANA. Oestradiol levels were decreased in obese male mice; however, VAT CYP1B1 and 16αOHE1 levels were increased. TMS also attenuated pulmonary hypertension in male ob/ob mice. Intra-thoracic fat from ob/ob mice and VAT conditioned media produce 16αOHE1 and can contribute to oxidative stress, effects that are attenuated by both ANA and TMS.Obesity can induce pulmonary hypertension and changes in oestrogen metabolism, resulting in increased production of 16αOHE1 from VAT that contributes to oxidative stress. Oestrogen inhibitors are now in clinical trials for PAH. This study has translational consequences as it suggests that oestrogen inhibitors may be especially beneficial in treating obese individuals with PAH.

Spontaneous Ca2+ transients in rat pulmonary vein cardiomyocytes are increased in frequency and become more synchronous following electrical stimulation.

The pulmonary veins have an external sleeve of cardiomyocytes that are a widely recognised source of ectopic electrical activity that can lead to atrial fibrillation. Although the mechanisms behind this activity are currently unknown, changes in intracellular calcium (Ca2+) signalling are purported to play a role. Therefore, the intracellular Ca2+ concentration was monitored in the pulmonary vein using fluo-4 and epifluorescence microscopy. Electrical field stimulation evoked a synchronous rise in Ca2+ in neighbouring cardiomyocytes; asynchronous spontaneous Ca2+ transients between electrical stimuli were also present. Immediately following termination of electrical field stimulation at 3 Hz or greater, the frequency of the spontaneous Ca2+ transients was increased from 0.45 ± 0.06 Hz under basal conditions to between 0.59 ± 0.05 and 0.65 ± 0.06 Hz (P < 0.001). Increasing the extracellular Ca2+ concentration enhanced this effect, with the frequency of spontaneous Ca2+ transients increasing from 0.45 ± 0.05 Hz to between 0.75 ± 0.06 and 0.94 ± 0.09 Hz after electrical stimulation at 3 to 9 Hz (P < 0.001), and this was accompanied by a significant increase in the velocity of Ca2+ transients that manifested as waves. Moreover, in the presence of high extracellular Ca2+, the spontaneous Ca2+ transients occurred more synchronously in the initial few seconds following electrical stimulation. The ryanodine receptors, which are the source of spontaneous Ca2+ transients in pulmonary vein cardiomyocytes, were found to be arranged in a striated pattern in the cell interior, as well as along the periphery of cell. Furthermore, labelling the sarcolemma with di-4-ANEPPS showed that over 90% of pulmonary vein cardiomyocytes possessed T-tubules. These findings demonstrate that the frequency of spontaneous Ca2+ transients in the rat pulmonary vein are increased following higher rates of electrical stimulation and increasing the extracellular Ca2+ concentration.