Groin dissections in skin cancer: Effect of a change in prophylactic antibiotic protocol.

OBJECTIVES: To determine whether groin dissection surgical site infection (SSI) incidence changed with shorter post-operative antibiotic prophylaxis. BACKGROUND: Post-operative prophylaxis changed due to antimicrobial stewardship, from regular oral antibiotics until drain removal, to three intravenous doses. Both groups had a single intravenous dose at induction. METHODS: A prospective database of groin dissections for metastatic skin cancer was retrospectively reviewed for SSI according to Public Health England criteria. Eighty groin dissections in 79 consecutive patients were included: 40 had oral antibiotics until drain removal [mean 26±7 (range 19-36) days] and 39 had three post-operative intravenous doses. RESULTS: Longer prophylaxis was associated with lower SSI incidence [10 (25%) versus 21 (54%), odds ratio (OR) 3.50, 95% confidence interval (CI) 1.34-9.08, p = 0.009], fewer deep infections [5 (13%) versus 16 (41%), OR 4.89, 95% CI 1.57-15.13, p = 0.004], fewer readmissions for infection [5 (13%) versus 15 (38%), OR 4.38, 95% CI 1.40-13.65, p = 0.008], but similar seroma incidence [18 (45%) versus 16 (41%), OR 0.85, 95% CI 0.35-2.07, p = 0.72] and wound dehiscence [7 (18%) versus 5 (13%), OR 0.69, 95% CI 0.20-2.40, p = 0.56]. BMI ≥30 (n = 21) was associated with SSI, occurring in 13 of 21 (62%) (OR 3.859, 95% CI 1.34-11.10, p = 0.01). Median infection onset was 22 days (IQR 12-27) versus 17 (IQR 13-22), (p = 0.53). Multiple organisms were cultured in 21 of 31 (68%) patients with positive microbiological samples. CONCLUSIONS: SSI rates doubled with shorter prophylaxis; deep infections and readmissions for infection tripled. Obesity was independently associated with infection. Seroma and wound dehiscence incidence were unchanged. Infections mainly occurred in the third week after surgery and were polymicrobial.

High concentrations of membrane-fed ivermectin are required for substantial lethal and sublethal impacts on Aedes aegypti.

BACKGROUND: With widespread insecticide resistance in mosquito vectors, there is a pressing need to evaluate alternatives with different modes of action. Blood containing the antihelminthic drug ivermectin has been shown to have lethal and sub-lethal effects on mosquitoes. Almost all work to date has been on Anopheles spp., but impacts on other anthropophagic vectors could provide new options for their control, or additional value to anti-malarial ivermectin programmes. METHODS: Using dose-response assays, we evaluated the effects of ivermectin delivered by membrane feeding on daily mortality (up to 14 days post-blood feed) and fecundity of an Indian strain of Aedes aegypti. RESULTS: The 7-day lethal concentration of ivermectin required to kill 50% of adult mosquitoes was calculated to be 178.6 ng/ml (95% confidence intervals 142.3-218.4) for Ae. aegypti, which is much higher than that recorded for Anopheles spp. in any previous study. In addition, significant effects on fecundity and egg hatch rates were only recorded at high ivermectin concentrations (≥ 250 ng/ul). CONCLUSION: Our results suggest that levels of ivermectin present in human blood at current dosing regimes in mass drug administration campaigns, or even those in a recent higher-dose anti-malaria trial, are unlikely to have a substantial impact on Ae. aegypti. Moreover, owing to the strong anthropophagy of Ae. aegypti, delivery of higher levels of ivermectin in livestock blood is also unlikely to be an effective option for its control. However, other potential toxic impacts of ivermectin metabolites, accumulation in tissues, sublethal effects on behaviour, or antiviral action might increase the efficacy of ivermectin against Ae. aegypti and the arboviral diseases it transmits, and require further investigation.

In thoracic aortic surgery, is innominate artery cannulation a safe and effective alternative to axillary artery cannulation?

A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was: in a patient undergoing thoracic aortic surgery, is innominate artery cannulation superior to axillary artery cannulation in terms of postoperative outcomes? Five hundred and thirty-one papers were found using the reported search strategy, of which 5 represented the best evidence to answer the clinical question. A total of 1338 participants were included across the 5 studies. Seven hundred and twenty-two patients were cannulated via the axillary artery and 616 were cannulated via the innominate artery. The included 5 studies were 2 prospective observational cohorts, 2 retrospective case-series analysis and a single-blinded randomized trial. Thirty-day or in-hospital mortality rates were reported in all 5 studies. There were no significant differences in mortality with innominate artery cannulation compared to axillary artery cannulation (P > 0.05), with slightly lower mortality rates in 2 studies, slightly higher mortality rates in 2 and equal in 1 study. Though statistical significance was not demonstrated (P > 0.05), a stroke occurred slightly less frequently in patients receiving innominate artery cannulation compared to axillary artery cannulation in 3 of the 4 studies. Innominate artery cannulation is non-inferior to axillary artery cannulation for thoracic aortic surgery, with a similar level of neuroprotection and is not associated with increased levels of mortality.