Characterizing Intraoperative Vasopressor Use in Total Knee Arthroplasty: A Retrospective Cohort Study.

Preoperative optimization and protocols for joint replacement care pathways have led to decreased length of stay (LOS)and narcotic use, and are increasingly important in delivering quality, cost savings, and shifting appropriate cases to an outpatient setting. The intraoperative use of vasopressors is independently associated with increased LOS and risk of adverse postoperative events including death, and in total hip arthroplasty, there is an increased risk for intensive care unit (ICU) admission. Our aim is to characterize the patient characteristics associated with vasopressor use specifically in total knee arthroplasty (TKA). We retrospectively reviewed the electronic medical records of a cohort of patients who underwent inpatient primary TKA at a single academic hospital from January 1, 2017 to December 31, 2018. Demographics, comorbidities, perioperative factors, and intraoperative medication administration were compared with multivariate regression to identify patients who may require intraoperative vasopressors. Out of these, 748 patients underwent TKA, 439 patients required intraoperative vasopressors, while 307 did not. Significant independent predictors of vasopressor use were older age (odds ratio [OR] = 1.06, 95% confidence interval [CI]: 1.03-1.08) and history of a prior cerebrovascular accident (CVA; OR = 11.80, CI: 1.48-93.81). While not significant, male sex (OR = 0.72, CI: 0.50-1.04) and regional anesthesia (OR = 0.64, CI: 0.40-1.05) were nearing significance as negative independent predictors of vasopressor use. In a secondary analysis, we did not observe an increase in complications attributable to vasopressor administration intraoperatively. In conclusion, nearly 59% of patients undergoing TKA received intraoperative vasopressor support. History of stroke and older age were significantly associated with increased intraoperative vasopressor use. As the first study to examine vasopressor usage in a TKA patient population, we believe that understanding the association between patient characteristics and intraoperative vasopressor support will help orthopaedic surgeons select the appropriate surgical setting during preoperative optimization.

Early Discharge After Total Hip Arthroplasty at an Urban Tertiary Care Safety Net Hospital: A 2-Year Retrospective Cohort Study.

INTRODUCTION: Previous studies have shown that shorter inpatient stays after total hip arthroplasty (THA) are safe and effective for select patient populations with limited medical comorbidity and perioperative risk. The purpose of our study was to compare the postoperative complications because they relate to the length of hospital stay at a safety net hospital in the urban area of the United States. METHODS: We retrospectively reviewed the medical records of 236 patients who underwent primary THA in 2017 at an urban safety net hospital. We collected data on demographics, medical comorbidities, and surgical admission information. Patients were categorized as "early discharge" if they were discharged on postoperative day 0 to 1 and "standard discharge" if they were discharged on postoperative day 2 to 5. The outcomes of interest were 90-day and 2-year postoperative complications, emergency department visit, readmissions, and revision surgeries. Data were analyzed using t-test or chi-square test for univariate analysis and linear logistic regression for controlled analysis. RESULTS: Compared with the standard discharge group, there were markedly more male patients in the early discharge group (44.5% versus 80%). Early discharge patients were markedly younger (53.3 versus 59.5 years old), more likely to be White/non-Hispanic (64.4% versus 42.4%) and less likely to have heart disease and diabetes (2.2% versus 15.2% and 2.2% versus 19.9%, respectively). With adjustment for these potential confounders, no notable difference was observed in all-type complications, emergency department visits, readmission, or revision surgery between the two groups. DISCUSSION: This study confirmed that early discharge after THA is as safe as standard discharge in a safety net hospital with appropriate preoperative risk screening. Increased perioperative counseling and optimization of social and medical risk factors mitigated possible risk factors for increased length of stay and surgical complication.

Mild Traumatic Brain Injury in Mice Beneficially Alters Lung NK1R and Structural Protein Expression to Enhance Survival after Pseudomonas aeruginosa Infection.

Mild traumatic brain injury (mTBI) in a murine model increases survival to a bacterial pulmonary challenge compared with blunt tail trauma (TT). We hypothesize substance P and its receptor, the neurokinin 1 receptor (NK1R; official name TACR1), play a role in the increased survival of mTBI mice. Mice were subjected to mTBI or TT, and 48 hours after trauma, the levels of NK1R mRNA and protein were significantly up-regulated in mTBI lungs. Examination of the lung 48 hours after injury by microarray showed significant differences in the expression of 433 gene sets between groups, most notably genes related to intercellular proteins. Despite down-regulated gene expression of connective proteins, the presence of an intact pulmonary vasculature was supported by normal histology and bronchoalveolar lavage protein levels. To determine whether these mTBI-induced lung changes benefited in vivo responses, two chemotactic stimuli (a CXCL1 chemokine and a live Pseudomonas aeruginosa infection) were administered 48 hours after trauma. For both stimuli, mTBI mice recruited more neutrophils to the lung 4 hours after instillation (CXCL1: mTBI = 6.3 ± 1.3 versus TT = 3.3 ± 0.7 neutrophils/mL; Pseudomonas aeruginosa: mTBI = 9.4 ± 1.4 versus TT = 5.3 ± 1.1 neutrophils/mL). This study demonstrates that the downstream consequences of mTBI on lung NK1R levels and connective protein expression enhance neutrophil recruitment to a stimulus that may contribute to increased survival.

Enhancing Scientific Foundations to Ensure Reproducibility: A New Paradigm.

Progress in science is dependent on a strong foundation of reliable results. The publish or perish paradigm in research, coupled with an increase in retracted articles from the peer-reviewed literature, is beginning to erode the trust of both the scientific community and the public. The NIH is combating errors by requiring investigators to follow new guidelines addressing scientific premise, experimental design, biological variables, and authentication of reagents. Herein, we discuss how implementation of NIH guidelines will help investigators proactively address pitfalls of experimental design and methods. Careful consideration of the variables contributing to reproducibility helps ensure robust results. The NIH, investigators, and journals must collaborate to ensure that quality science is funded, explored, and published.

The Role of Substance P in Pulmonary Clearance of Bacteria in Comparative Injury Models.

Neural input to the immune system can alter its ability to clear pathogens effectively. Patients suffering mild traumatic brain injury (mTBI) have shown reduced rates of pneumonia and a murine model replicated these findings, with better overall survival of TBI mice compared with sham-injured mice. To further investigate the mechanism of improved host response in TBI mice, this study developed and characterized a mild tail trauma model of similar severity to mild TBI. Both mild tail trauma and TBI induced similar systemic changes that normalized within 48 hours, including release of substance P. Examination of tissues showed that injuries are limited to the target tissue (ie, tail in tail trauma, brain in mTBI). Pneumonia challenge showed that mild TBI mice showed improved immune responses, characterized by the following: i) increased survival, ii) increased pulmonary neutrophil recruitment, iii) increased bacterial clearance, and iv) increased phagocytic cell killing of bacteria compared with tail trauma. Administration of a neurokinin-1-receptor antagonist to block substance P signaling eliminated the improved survival of mTBI mice. Neurokinin-1-receptor antagonism did not alter pneumonia mortality in tail trauma mice. These data show that immune benefits of trauma are specific to mTBI and that tail trauma is an appropriate control for future studies aimed at elucidating the mechanisms of improved innate immune responses in mTBI mice.

Shorter Duration of Post-Operative Antibiotics for Cecal Ligation and Puncture Does Not Increase Inflammation or Mortality.

Antimicrobial therapy for sepsis has beneficial effects, but prolonged use fosters emergence of resistant microorganisms, increases cost, and secondary infections. We tested whether 3 days versus 5 days of antibiotics in the murine model of cecal ligation and puncture (CLP) negatively influences outcomes. Following CLP mice were randomized to receive the antibiotic imipenem-cilastatin (25mg/kg) in dextrose 5% in Lactated Ringer's solution every 12 hours for either three or five days. Serial monitoring over 28 days included body weight, temperature, pulse oximetry, and facial vein sampling for hematological analysis and glucose. A separate group of mice were euthanized on post-CLP day 5 to measure cytokines and peritoneal bacterial counts. The first study examined no antimicrobial therapy and demonstrated that antibiotics significantly improved survival compared to fluids only (p = 0.004). We next tested imipenem-cilastatin therapy for 3 days versus 5 days. Body weight, temperature, glucose, and pulse oximetry measurements remained generally consistent between both groups as did the hematological profile. Pro-inflammatory plasma cytokines were comparable between both groups for IL-6, IL-1ß, MIP-2 and anti-inflammatory cytokines IL-10, and TNF SRI. At 5 days post-CLP, i.e. 2 days after the termination of antibiotics in the 3 day group, there were no differences in the number of peritoneal bacteria. Importantly, shortening the course of antibiotics by 40% (from 5 days to 3 days) did not decrease survival. Our results indicate that reducing the duration of broad-spectrum antibiotics in murine sepsis did not increase inflammation or mortality.

Anatomic total shoulder arthroplasty for patients receiving workers' compensation.

BACKGROUND: Studies have demonstrated that receiving workers' compensation (WC) benefits can be a negative predictor of outcomes after orthopedic procedures. This study compares postoperative outcomes of anatomic total shoulder arthroplasty (TSA) between patients receiving WC benefits and a control group that did not. METHODS: A cohort of 13 consecutive TSA patients with WC benefits were compared with a control group of 63 consecutive patients with a minimum of 2 years of follow-up during the same period. Patient demographics, American Shoulder and Elbow Surgeons scores, 12-Item Short Form Health Survey scores, return to work status, and time out of work were evaluated. RESULTS: The WC TSA cohort consisted of 13 men and no women with a mean age of 55.9 years. Twelve of the 13 were laborers. The TSA control group consisted of 36 men and 27 women with a mean age of 63.2 years (P = .01). The American Shoulder and Elbow Surgeons scores at final follow-up were significantly lower in the WC cohort (73.6) compared with the control group (86.6; P = .01). However, the 12-Item Short Form Health Survey physical and mental component summary scores were not significantly different (P = .09 and P = .6). Only 4 of the 13 WC patients returned to work. CONCLUSION: Compared with a non-WC population, patients with WC who received an anatomic TSA are more likely to be male, younger, and a laborer. Outcomes are generally excellent and better than those of other WC shoulder surgery cohorts in the literature; however, the outcomes are relatively worse than in the non-WC TSA patients. A significant number of WC patients are unable to return to work after TSA.