Purpose To evaluate and analyze the impact of lockdown strategy due to coronavirus disease 2019 (COVID-19) on emergency general surgery (EGS) in the Milan area at the beginning of pandemic outbreak. Methods A survey was distributed to 14 different hospitals of the Milan area to analyze the variation of EGS procedures. Each hospital reported the number of EGS procedures in the same time frame comparing 2019 and 2020. The survey revealed that the number of patients during the COVID-19 pandemic outbreak in 2020 was reduced by 19% when compared with 2019. The decrease was statistically significant only for abdominal wall surgery. Interestingly, in 2020, there was an increase of three procedures: surgical intervention for acute mesenteric ischemia ( p = 0.002), drainage of perianal abscesses ( p = 0.000285), and cholecystostomy for acute cholecystitis ( p = 0.08). Conclusions During the first COVID-19 pandemic wave in the metropolitan area of Milan, the number of patients operated for emergency diseases decreased by around 19%. We believe that this decrease is related either to the fear of the population to ask for emergency department (ED) consultation and to a shift towards a more non-operative management in the surgeons ‘decision making’ process. The increase of acute mesenteric ischaemia and perianal abscess might be related to the modification of dietary habits and reduction of physical activity related to the lockdown.

After colorectal resection, PPOI leads to a prolonged hospital stay and slower patient's recovery. An international standardized definition of PPOI is strongly needed to make comparable results from researches and to reliably identify patients with increased risk, also to improve the therapeutic preventive policies in these patients.

Introduction ERAS pathway has been proposed as the standard of care in elective abdominal surgery. Guidelines on ERAS in emergency surgery have been recently published; however, few evidences are still available in the literature. The aim of this study was to evaluate the feasibility of an enhanced recovery protocol in a large cohort of patients undergoing emergency surgery and to identify possible factors impacting postoperative protocol compliance. Methods This is a prospective multicenter observational study including patients who underwent major emergency general surgery for either intra-abdominal infection or intestinal obstruction. The primary endpoint of the study is the adherence to ERAS postoperative protocol. Secondary endpoints are 30-day mortality and morbidity rates, and length of hospital stay. Results A total of 589 patients were enrolled in the study, 256 (43.5%) of them underwent intestinal resection with anastomosis. Major complications occurred in 92 (15.6%) patients and 30-day mortality was 6.3%. Median adherence occurred on postoperative day (POD) 1 for naso-gastric tube removal, on POD 2 for mobilization and urinary catheter removal, and on POD 3 for oral intake and i.v. fluid suspension. Laparoscopy was significantly associated with adherence to postoperative protocol, whereas operative fluid infusion > 12 mL/Kg/h, preoperative hyperglycemia, presence of a drain, duration of surgery and major complications showed a negative association. Conclusions The present study supports that an enhanced recovery protocol in emergency surgery is feasible and safe. Laparoscopy was associated with an earlier recovery, whereas preoperative hyperglycemia, fluid overload, and abdominal drain were associated with a delayed recovery.

A Reduced Ordered Binary Decision Diagram (ROBDD) is a data structure widely used in an increasing number of fields of Computer Science. In general, ROBDD representations of Boolean functions have a tractable size, polynomial in the number of input variables, for many practical applications. However, the size of a ROBDD, and consequently the complexity of its manipulation, strongly depends on the variable ordering: depending on the initial ordering of the input variables, the size of a ROBDD representation can grow from linear to exponential. In this paper, we study the ROBDD representation of Boolean functions that describe a special class of Boolean affine spaces, which play an important role in some logic synthesis applications. We first discuss how the ROBDD representations of these functions are very sensitive to variable ordering, and then provide an efficient linear time algorithm for computing an optimal variable ordering that always guarantees a ROBDD of size linear in the number of input variables.