Peri-operative SARS-CoV-2 infection increases postoperative mortality. The aim of this study was to determine the optimal duration of planned delay before surgery in patients who have had SARS-CoV-2 infection. This international, multicentre, prospective cohort study included patients undergoing elective or emergency surgery during October 2020. Surgical patients with pre-operative SARS-CoV-2 infection were compared with those without previous SARS-CoV-2 infection. The primary outcome measure was 30-day postoperative mortality. Logistic regression models were used to calculate adjusted 30-day mortality rates stratified by time from diagnosis of SARS-CoV-2 infection to surgery. Among 140,231 patients (116 countries), 3127 patients (2.2%) had a pre-operative SARS-CoV-2 diagnosis. Adjusted 30-day mortality in patients without SARS-CoV-2 infection was 1.5% (95%CI 1.4-1.5). In patients with a pre-operative SARS-CoV-2 diagnosis, mortality was increased in patients having surgery within 0-2 weeks, 3-4 weeks and 5-6 weeks of the diagnosis (odds ratio (95%CI) 4.1 (3.3-4.8), 3.9 (2.6-5.1) and 3.6 (2.0-5.2), respectively). Surgery performed ≥ 7 weeks after SARS-CoV-2 diagnosis was associated with a similar mortality risk to baseline (odds ratio (95%CI) 1.5 (0.9-2.1)). After a ≥ 7 week delay in undertaking surgery following SARS-CoV-2 infection, patients with ongoing symptoms had a higher mortality than patients whose symptoms had resolved or who had been asymptomatic (6.0% (95%CI 3.2-8.7) vs. 2.4% (95%CI 1.4-3.4) vs. 1.3% (95%CI 0.6-2.0), respectively). Where possible, surgery should be delayed for at least 7 weeks following SARS-CoV-2 infection. Patients with ongoing symptoms ≥ 7 weeks from diagnosis may benefit from further delay.

A rapid, accurate and sensitive method has been developed for the quantitative determination of four fluoroquinolone antimicrobial agents, enoxacin, norfloxacin, ofloxacin and ciprofloxacin, with high in-vitro activity against a wide range of Gram-negative and Gram-positive organisms.A Kromasil 100 C(8) 250 mm x 4 mm, 5 microm analytical column was used with an eluting system consisting of a mixture of CH(3)CN-CH(3)OH-citric acid 0.4 mol L(-1) (7:15:78 %, v/v). Detection was performed with a variable wavelength UV-visible detector at 275 nm resulting in limits of detection: 0.02 ng per 20 microL injection for enoxacin and 0.01 ng for ofloxacin, norfloxacin and ciprofloxacin. Hydrochlorothiazide (HCT) was used as internal standard at a concentration of 2 ng microL(-1). A rectilinear relationship was observed up to 2 ng microL(-1) for enoxacin, 12 ng microL(-1) for ofloxacin, 3 ng microL(-1) for norfloxacin, and 5 ng microL(-1) for ciprofloxacin. Separation was achieved within 10 min. The statistical evaluation of the method was examined by performing intra-day (n=8) and inter-day precision assays (n=8) and was found to be satisfactory with high accuracy and precision. The method was applied to the direct determination of the four fluoroquinolones in human blood serum. Sample pretreatment involved only protein precipitation with acetonitrile. Recovery of analytes in spiked samples was 97+/-6% over the range 0.1-0.5 ng microL(-1).

SARS-CoV-2 has been associated with an increased rate of venous thromboembolism in critically ill patients. Since surgical patients are already at higher risk of venous thromboembolism than general populations, this study aimed to determine if patients with peri-operative or prior SARS-CoV-2 were at further increased risk of venous thromboembolism. We conducted a planned sub-study and analysis from an international, multicentre, prospective cohort study of elective and emergency patients undergoing surgery during October 2020. Patients from all surgical specialties were included. The primary outcome measure was venous thromboembolism (pulmonary embolism or deep vein thrombosis) within 30 days of surgery. SARS-CoV-2 diagnosis was defined as peri-operative (7 days before to 30 days after surgery); recent (1-6 weeks before surgery); previous (≥7 weeks before surgery); or none. Information on prophylaxis regimens or pre-operative anti-coagulation for baseline comorbidities was not available. Postoperative venous thromboembolism rate was 0.5% (666/123,591) in patients without SARS-CoV-2; 2.2% (50/2317) in patients with peri-operative SARS-CoV-2; 1.6% (15/953) in patients with recent SARS-CoV-2; and 1.0% (11/1148) in patients with previous SARS-CoV-2. After adjustment for confounding factors, patients with peri-operative (adjusted odds ratio 1.5 (95%CI 1.1-2.0)) and recent SARS-CoV-2 (1.9 (95%CI 1.2-3.3)) remained at higher risk of venous thromboembolism, with a borderline finding in previous SARS-CoV-2 (1.7 (95%CI 0.9-3.0)). Overall, venous thromboembolism was independently associated with 30-day mortality ). In patients with SARS-CoV-2, mortality without venous thromboembolism was 7.4% (319/4342) and with venous thromboembolism was 40.8% (31/76). Patients undergoing surgery with peri-operative or recent SARS-CoV-2 appear to be at increased risk of postoperative venous thromboembolism compared with patients with no history of SARS-CoV-2 infection. Optimal venous thromboembolism prophylaxis and treatment are unknown in this cohort of patients, and these data should be interpreted accordingly.

Background The Hawthorne effect or ‘observer effect’ describes a change in normal behaviour when individuals are aware they are being observed. This may have an impact on effect estimates in clinical trials. The purpose of this study was to determine if the Hawthorne effect had been recorded as a risk of bias in surgical studies. Methods A Preferred Reporting Items for Systematic Reviews and Meta‐Analyses compliant literature search was conducted till March 2019. Eligible studies included those reporting or not reporting the Hawthorne effect in surgical studies from the following databases: MEDLINE, Embase, CINAHL, AMED, BNI, HMIC, PsycINFO, Web of Science, Cochrane Library, Google Scholar and OpenGrey. Two reviewers independently reviewed the papers, extracted data and appraised study methods using the Newcastle Ottawa Scale or the Cochrane risk of bias tool. Data were analysed descriptively. Results A total of 842 papers were identified, of which 16 were eligible. Six (37%) observational studies were identified with the aim of measuring the Hawthorne effect on their outcome with five reporting that the Hawthorne effect was responsible for the improvements in outcomes and one reporting no change in outcome due to the Hawthorne effect. Ten (63%) studies were identified, of which eight used the Hawthorne effect as an explanation to improvements seen in the control group or their secondary outcomes and two to compare their results with other studies. Conclusion There is considerable between‐study heterogeneity on how the Hawthorne effect relates to surgical outcomes. Further consideration on reporting and considering the importance of the Hawthorne effect in the design of surgical trials is warranted.

The presentation and clinical course of mucoid degeneration of the anterior cruciate ligament (MD-ACL) are poorly documented within the literature. Subsequently, it is under-diagnosed and the optimal management strategy remains ill-defined. Here, we characterize the syndrome associated with MD-ACL and compare the natural clinical course with the outcomes of arthroscopic management. Thirty-one patients with radiological features of MD-ACL over a 2-year period had their clinical notes retrospectively reviewed. Seven patients underwent arthroscopic debridement of the ACL for MD. These were followed up for a minimum of 2 years and an average of 2.8 years from surgery. The remainder were managed conservatively ( = 24) and were followed up for a minimum of 2 years and an average of 4.0 years. The notch width index (NWI) and associated pathology was noted. Primary outcome measures were presence of knee pain and use of analgesia. Secondary outcome measures were the Oxford and Lysholm knee scores. The most commonly reported symptoms were posterior knee pain (77.4%) and limitation of terminal flexion (58.1%). All patients who underwent arthroscopic debridement were pain and analgesia free at follow-up. Of the patients who did not undergo arthroscopic surgery, three patients had knee replacement surgery and three were lost to follow-up. The remaining patients, 14/18 (77.8%), reported knee pain and regular analgesia use at follow-up, which was significantly more than the arthroscopic debridement group ( < 0.01). The knee scores were significantly better in the arthroscopic debridement group at follow-up (Oxford knee score: 45 vs 34; Lysholm: 92 vs 67; < 0.01). Furthermore, the postoperative improvement in the Oxford knee and Lysholm scores compared with preoperatively was 12.1 and 31.8 points, respectively ( < 0.01). The NWI was increased in patients with mild-to-severe osteoarthritis (0.266 vs 0.273; < 0.05). MD-ACL should be considered in patients who report posterior knee pain, limitation of terminal flexion, and it can be associated with other knee pathologies. MD-ACL can be successfully managed with arthroscopic radio frequency debulking with improvement in quality of life at follow-up.