Antibiotics after Simple (Acute) Appendicitis Are Not Associated with Better Clinical Outcomes: A Post-Hoc Analysis of an EAST Multi-Center Study

Background:The post-operative management of simple (acute) appendicitis differs throughout the United States. Guidelines regarding post-operative antibiotic usage remain unclear, and treatment generally is dictated by surgeon preference. We hypothesize that post-operative antibiotic use for simple appendicitis is not associated with lower post-operative complication rates. Methods:In a post-hoc analysis in a large multi-center observational study, only patients with an intra-operative diagnosis of AAST EGS Grade I were included. Subjects were classified into those receiving post-operative antibiotics (POST) and those given pre-operative antibiotics only (NONE). Clinical outcomes examined were length of stay (LOS), 30-day emergency department (ED) visits and hospital re-admissions, secondary interventions, surgical site infection (SSI), and intra-abdominal abscess (IAA). Results:A total of 2,191 subjects were included, of whom 612 (28%) received post-operative antibiotics. Compared with the NONE group, POST patients were older (age 37 [range 26-50] versus 33 [26-46] years; p < 0.001), weighed more (82 [70-96] versus 79 [68-93] kg (p = 0.038), and had higher white blood cell counts (13.5 +/- 4.2 versus 13.1 +/- 4.4/10(3)/mcL (p = 0.046), Alvarado Scores (6 [5-7] versus 6 [5-7]; p < 0.001), and Charlson Comorbidity Indices (median score 0 in both cohorts; p < 0.001). The POST patients had a longer LOS (1 [1-2] versus 1 [1-1] days; p < 0.001). There were no differences in the number who had ED visits within 30 days (9% versus 8%; p = 0.435), hospital re-admission (4% versus 2%; p = 0.165), an index hospitalization SSI (0.2% for both cohorts; p = 0.69), an SSI within 30 days (4% versus 2%; p = 0.165), index hospitalization IAA rate (0.3% versus 0.1%; p = 0.190), 30-day IAA (2% versus 1%; p = 0.71), index hospitalization interventions (0.5% versus 0.1%; p = 0.137) or 30-day secondary interventions (2% versus 1%; p = 0.155). Conclusions:Post-operative antibiotic use after appendectomy for simple appendicitis is not associated with better post-operative clinical outcomes at index hospitalization or at 30 days after discharge

Multicenter Study of the Treatment of Appendicitis in America Acute, Perforated, and Gangrenous (MUSTANG), an EAST Multicenter Study

Objective: We sought to describe contemporary presentation, treatment, and outcomes of patients presenting with acute (A), perforated (P), and gangrenous (G) appendicitis in the United States. Summary Background Data: Recent European trials have reported that medical (antibiotics only) treatment of acute appendicitis is an acceptable alternative to surgical appendectomy. However, the type of operation (open appendectomy) and average duration of stay are not consistent with current American practice and therefore their conclusions do not apply to modern American surgeons. Methods: This multicenter prospective observational study enrolled adults with appendicitis from January 2017 to June 2018. Descriptive statistics were performed. P and G were combined into a "complicated" outcome variable and risk factors were assessed using multivariable logistic regression. Results: A total 3597 subjects were enrolled across 28 sites: median age was 37 (27-52) years, 1918 (53%) were male, 90% underwent computed tomography (CT) imaging, 91% were initially treated by appendectomy (98% laparoscopic), and median hospital stay was 1 (1-2) day. The 30-day rates of Emergency Department (ED) visit and readmission were 10% and 6%. Of 219 initially treated with antibiotics, 35 (16%) required appendectomy during index hospitalization and 12 (5%) underwent appendectomy within 30 days, for a cumulative failure rate of 21%. Overall, 2403 (77%) patients had A, whereas 487 (16%) and 218 (7%) patients had P and G, respectively. On regression analysis, age, symptoms >48 hours, temperature, WBC, Alvarado score, and appendicolith were predictive of "complicated" appendicitis, whereas co-morbidities, smoking, and ED triage to appendectomy >6 hours or >12 hours were not. Conclusion: In the United States, the majority of patients presenting with appendicitis receive CT imaging, undergo laparoscopic appendectomy, and stay in the hospital for 1 day. One in five patients selected for initial non-operative management required appendectomy within 30 days. In-hospital delay to appendectomy is not a risk factor for "complicated" appendicitis

Development and in-vivo validation of a portable phosphorescence lifetime-based fiber-optic oxygen sensor

Abstract Oxygenation is a crucial indicator of tissue viability and function. Oxygen tension ( $$\hbox {pO}_2$$ pO 2 ), i.e. the amount of molecular oxygen present in the tissue is a direct result of supply (perfusion) and consumption. Thus, measurement of $$\hbox {pO}_{{2}}$$ pO 2 is an effective method to monitor tissue viability. However, tissue oximetry sensors commonly used in clinical practice instead rely on measuring oxygen saturation ( $$\hbox {StO}_2$$ StO 2 ), largely due to the lack of reliable, affordable $$\hbox {pO}_2$$ pO 2 sensing solutions. To address this issue we present a proof-of-concept design and validation of a low-cost, lifetime-based oxygen sensing fiber. The sensor consists of readily-available off-the shelf components such as a microcontroller, a light-emitting diode (LED), an avalanche photodiode (APD), a temperature sensor, as well as a bright in-house developed porphyrin molecule. The device was calibrated using a benchtop setup and evaluated in three in vivo animal models. Our findings show that the new device design in combination with the bright porphyrin has the potential to be a useful and accurate tool for measuring $$\hbox {pO}_2$$ pO 2 in tissue, while also highlighting some of the limitations and challenges of oxygen measurements in this context