Antibiotic prophylaxis for hysterectomy, a prospective cohort study. Cefuroxime, metronidazole or both? This is an outline of our presentation. We’ll start off the background, aim, methods, and results. Then we’ll go on to criticisms, literature review, and summary of findings. This paper is a National Collaborative Prospective Observational study done in Finland, also known as FINHYST 2006. It is done across 53 hospitals. There are 5,279 hysterectomies performed for benign indications. Data on indications, antibiotics, and thrombosis prophylaxis [INAUDIBLE] were collected. According to a NICE guidelines, before any clean-contaminated surgeries, antibiotic prophylaxis should be given. However, no specific antibiotic was recommended. According to ACOG recommendation, for any gynecological procedures, cefazolin 1 or 2 grams should be used. The aim of this paper is to evaluate cefuroxime and metronidazole in the prevention of post-operative infections. Methods. A prospective of the original study was done across 53 hospitals. For every patient, a study form was completed at discharge by the surgeon. At follow ups at the outpatient clinics, a separate form was completed for each patient in the case of infections. Patients were not randomized or allocated to any form of antibiotics. The antibiotics used were chosen based on local hospital policies or according to the surgeon’s preference. Logistic regression was used for analysis. In this paper, post-operative wound infection, urinary tract infection, febrile event, pelvic infection, total infection are defined as on the slide. Results. Out of the 5,279 hysterectomies, data was only available for 5,240, of which 2.5% were not given any antibiotic prophylaxis. Cefuroxime alone was given to 38.5%, and metronidazole alone was given for 9.9%. Both cefuroxime and metronidazole were given to 43% of the patients. The rest of the patients were given other antibiotic prophylaxis. For dosage-wise, cefuroxime dose was only reported 38% of the time, of which majority used IV 1.5 grams. Metronidazole dose was reported 24% of the time, of which majority used IV 0.5 grams. In view of the lack of data on dosage, the use of antibiotics were analyzed irrespective of dosage. Of all the hysterectomies done, majority, 44%, were vaginal hysterectomies. The rest were abdominal and laparoscopic hysterectomies at 24% and 32%, respectively. This table shows the results broken down into type of hysterectomies and prophylaxis given versus the total infection rate. Of note, if metronidazole is used alone for prophylaxis, occurrence of total infections is increased for all types of hysterectomies. This table compares the risk of infections if cefuroxime was used versus if cefuroxime was not used, including cases where other types of antibiotics were given. Similarly, for metronidazole, it compared risk for infections if metronidazole was used versus if metronidazole was not used. The results showed a significant risk-reductive effect if cefuroxime was used. On metronidazole, there was no significant risk-reductive effect. This table compares the risk of infections when cefuroxime was used versus a combination of cefuroxime with metronidazole. Similarly, we also compared the risk of infections if metronidazole was used versus a combination of cefuroxime with metronidazole. For metronidazole, there was a significant increase in risk of total infections, especially febrile events. For cefuroxime, there was no significant difference. This graph shows that longer the operation, the higher the risk of infection. With metronidazole alone, there was a high increase in infection rate. But between cefuroxime and a combination of cefuroxime and metronidazole, there was no significant difference. In conclusion, the findings of the paper were that cefuroxime was effective as prophylaxis against infection. Cefuroxime combined with metronidazole offered no additional benefit. Metronidazole alone appeared to be ineffective. The results of this paper could be attributed to the fact that metronidazole has a limited spectrum, as it deals mainly with anaerobes. For cefuroxime, which is a second-generation cephalosporin, it has activity against a wide range of aerobic and anaerobic gram-positive and gram-negative organisms. Now, we move on to our critique of the paper. Firstly, no method was used to randomize or allocate patients, which resulted in a vast difference in sampling rate. As shown in this table, metronidazole alone was used in only less than 10% of the operations. Another confounding factor was the fact that dosage and route of administration of the antibiotics were not reported for more than 60% of the patients. For metronidazole, while it was mostly administered through IV, other routes, for example, IM, RO, and per vagina were also used for some cases. We are unable to tell if there were any underlying factors that led to the choice of the antibiotics. For example, surgeons might have chosen a combination of metronidazole and cefuroxime for more complicated surgeries. In addition, the duration of follow up for infections was not specified. In some cases of mouth infections, instead of visiting the hospital’s outpatient clinics, patients could have visited a GP instead. This infection would have been missed and not recorded in the results. In our literature review, it was found that there are other papers that supported the results of this paper. The conclusion of these papers are shown on this slide. However, locally we used cefazolin instead cefuroxime as prophylaxis, and there have so far been no papers comparing this to antibiotics. In summary, the findings clearly show that cefuroxime is better than metronidazole for prophylaxis. This could be due to the wider spectrum of cefuroxime. However, lack of information on dosage of the drug is a severe confounding factor. In terms of our local context, we will also need to compare cefazolin and cefuroxime and cefazolin in combination with metronidazole in hysterectomies. Thank you for listening to this presentation.