Background: Same-day discharge, defined as discharge from the hospital within 24 h of surgery, has been shown to be safe for joint arthroplasty. We examined demographic and clinical factors associated with same-day discharge and unplanned readmission following shoulder arthroplasty in adult patients.Methods: Utilizing data from the American College of Surgeons National Surgical Quality Improvement Program database, we extracted information of all patients that underwent shoulder arthroplasty. The primary and secondary outcome of interest was same-day discharge and 30-day unplanned readmission, respectively. We utilized multivariable logistic regression to identify covariates associated with these outcomes. Results: There were 17,011 patients analyzed when identifying predictors for same-day discharge. There was an increase in same-day discharge from 2007 to 2016. The odds of same-day discharge were significantly better for males (P < 0.001). The odds of same-day discharge was significantly decreased for every 10-year increase in age and for patients with insulin dependent diabetes, poor functional status, chronic obstructive pulmonary disease, congestive heart failure, bleeding disorder, and comorbidity burden (all P < 0.001). There were 14,276 patients analyzed for hospital readmission. The odds of unplanned readmission were significantly higher for every 10-year increase in age and for patients with poor functional status, congestive heart failure, bleeding disorder, and higher comorbidity burden (all P < 0.001). Conclusions: The results of this study show that preoperative comorbidities and advanced age reduce the odds of same-day discharge. Risk stratification, preoperative optimization, and coordinated care after surgery may be helpful to optimize patients for same-day discharge.

Pancreatic ductal adenocarcinoma (PDAC) has one of the lowest 5-year survival rates of all cancers, and limited treatment options exist. Immunotherapy is effective in some cancer types, but the immunosuppressive tumor microenvironment (TME) of PDAC is a barrier to effective immunotherapy. CXCR2+ myeloid-derived suppressor cells (MDSCs) are abundant in PDAC tumors in humans and in mouse models. MDSCs suppress effector cell function, making them attractive targets for restoring anti-tumor immunity. In this study, we show that the most abundant soluble factors released from a genetically diverse set of human and mouse PDAC cells are CXCR2 ligands, including CXCL8, CXCL5, and CXCL1. Expression of CXCR2 ligands is at least partially dependent on mutant KRAS and NFκB signaling, which are two of the most commonly dysregulated pathways in PDAC. We show that MDSCs are the most prevalent immune cells in PDAC tumors. MDSCs expressed high levels of CXCR2, and we found that myeloid cells readily migrate toward conditioned media (CM) prepared from PDAC cultures. We designed CXCR2 ligand-Fc fusion proteins to modulate the CXCR2 chemotactic signaling axis. Unexpectedly, these fusion proteins were superior to native chemokines in binding and activation of CXCR2 on myeloid cells. These “superkines” were potent inhibitors of PDAC CM-induced myeloid cell migration and were superior to CXCR2 small-molecule inhibitors and neutralizing antibodies. Our findings suggest that CXCR2 superkines may disrupt myeloid cell recruitment to PDAC tumors, ultimately improving immunotherapy outcomes in patients with PDAC.