Polymerase Chain Reaction (PCR) and Cultivation of the Peritoneal Fluid at Operation for Appendicitis and Postoperative Enteral Antibiotic Treatment
Polymerase Chain Reaction (PCR) and Cultivation of the Peritoneal Fluid at Operation for Appendicitis and Postoperative Enteral Antibiotic Treatment
Patients diagnosed with acute appendicitis receives antibiotics during the operation, and
 only patients where the surgeon suspects a complicated appendicitis with spread inflammation
 to the abdominal cavity receive antibiotics for 3 days postoperative.

 In a previous study at the surgical department, the investigators were able to show that the
 surgeon's assessment during the surgery of whether the appendicitis are complicated or not is
 very uncertain. This means that some patients receive antibiotics after surgery for no
 reason, and others might have benefited from antibiotics. The aim of this study is to solve
 this problem.

 By extracting some of the peritoneal fluid, it is possible to investigate whether there are
 bacteria or not in the abdominal cavity. Today when the fluid is cultivated, the answer will
 appear after 3-4 days. Therefore a new method is needed which confirms the presence of
 bacteria in the abdominal cavity within 24 hours.

 In this study growth of bacteria in cultivation is examined and determined within 24 hours.
 The study also want to use PCR analysis. It is a special technique, which examines the fluid
 from the abdominal cavity for bacteria and provide answer within a few hours. It is
 investigated whether it is possible to perform this method in the daily routine of the
 department.

 New research also shows that if patients needs antibiotics after surgery they can be treated
 with tablets instead of injection into the blood vessel. Antibiotic treatment with tablets
 will mean that the patient can be discharged earlier.

 The primary purpose of this study is to investigate whether it is possible with the PCR
 technique or cultivation to determine whether there are bacteria in the abdominal cavity of
 patients undergoing surgery for acute appendicitis or not, so that any continued antibiotic
 treatment after surgery can be targeted to the individual patient. The secondary purpose is
 to investigate whether antibiotic treatment with tablets are as effective as getting
 antibiotics into the blood vessel.

 The patients participating in the project will undergo the usual routine treatment and
 surgery. The only exception is retrieval of the naturally occurring fluid from the abdominal
 cavity. This will be done during the operation by special suction equipment that can be
 fitted to the usual operating equipment. It will not cause any discomfort or inconvenience to
 the patient. The technique of extracting fluid from the abdominal cavity has been used in
 previous studies of patients operated on for acute appendicitis.

 The benefit for the patient will be a more targeted antibiotic treatment so that both
 unnecessary treatment is avoided, and patients who previously would not have received
 treatment can benefit from this. For society a more targeted antibiotic treatment will mean
 less risk of developing resistance and less hospitalization.
Aim The primary aim is to investigate whether it is possible to determine if there are
 bacteria in the patient's peritoneal fluid either from PCR (polymerase chain reaction) or
 cultivation within 24 hours in patients undergoing surgery for acute appendicitis.

 The secondary purpose is to investigate whether oral administered postoperative antibiotic
 treatment is non-inferior to prior standard intravenous administration therapy focusing on
 wound infection and intra-abdominal abscess.

 The clinical issues

 Previous studies from our department have shown that both over- and under treatment with
 antibiotics in patients operated for acute appendicitis is reality. It has not previously
 been possible to control the treatment based on the result of peritoneal fluid culture,
 because the final response to conventional cultivation is first available after a 3-4 days.
 The PCR (polymerase chain reaction) technique allows diagnostics within hours.

 The second problem is that conventional postoperative antibiotic treatment is most often the
 only reason for the patient to remain hospitalized for at least 3 days. With oral antibiotic
 treatment the patient can be treated at home.

 Hypotheses

 -  In case of acute appendicitis surgery, it is possible to determine the presence of
 bacteria in the peritoneal fluid by PCR or culture within 24 hours, and that the final
 response to D + R after a further 3 days of culture is consistent with this.

 -  Oral postoperative antibiotic therapy is non-inferior to traditional intravenous
 administration in complicated appendicitis.

 Background Acute appendicitis surgery is one of the most frequent operations with a lifetime
 risk of approximately 9%.

 Appendicitis can be classified as uncomplicated (phlegmonous) or complicated (gangrenous,
 perforated or peri appendicular abscess) based on perioperative findings. Perioperative
 antibiotics prophylaxis is administered to all patients, who are operated for acute
 appendicitis, whether there is complicated or uncomplicated appendicitis due to prevent
 complications. The complications are primarily wound infection or intra-abdominal abscess. In
 complicated appendicitis treatment continues for three days after surgery. The antibiotic
 treatment targets both aerobic and anaerobic intestinal bacteria. Several antibiotic regimens
 have been found to be equivalent. In our department, cefuroxime and metronidazole as
 intravenous administration are used as standard.

 It is the surgeon who alone determine whether an appendicitis is complicated by the findings
 under the surgery. A previous study conducted in the ward showed that in 42% of the cases
 where the surgeon assessed that the appendix was perforated, no bacterial growth could be
 detected by growing on perioperatively retrieved peritoneal fluid, while in 18% of cases
 where the histology showed simply phlegmonous appendicitis, there was a positive culture
 result. Therefore, there is a risk of both under- and over treatment, which is inappropriate
 for many reasons, including increased resistance development. Therefore, a more
 evidence-based approach to postoperative antibiotic treatment after surgery for acute
 appendicitis is needed.

 A prerequisite to organize a more appropriate antibiotic treatment will be the ability to
 obtain a reliable culture result from peritoneal fluid within 24 hours. Conventional
 cultivation can be problematic because not all bacteria will show growth within this time.
 PCR could be a better method and an alternative to ordinary culture.

 If it is found that it is possible within 24 hours after the operation to determine whether
 there is growth of bacteria in the peritoneal fluid, it will be possible to let this
 determine if continued postoperative treatment are needed regardless of the operative
 findings, thus reducing the risk of under- or overtreatment.

 Another important clinical question is whether antibiotics should be given intravenous or
 oral. Oral treatment will be convenient for both the patient and the health care system, as
 the patient will then be able to be treated at home. A previous retrospective Danish study
 has shown that oral antibiotic treatment is equivalent to intravenous treatment and that the
 hospitalization time can be reduced by an average of 61 hours. Oral treatment has been
 introduced in some Danish hospitals.

 Method The study design is a prospective cohort/feasibility and non-inferior study, which
 includes a total of 100 patients older than 18 who undergo an appendectomy due to acute
 appendicitis.

 When diagnostic laparoscopy is performed and appendicitis is recognized, 10 ml of peritoneal
 fluid is extracted for examination by special equipment approved for this purpose. In the
 absence of peritoneal fluid, the surgeon will rinse with 20 ml of sterile saline
 corresponding to the peri appendicular area. The peritoneal fluid is then sent for PCR,
 culture and resistance determination.

 When these procedures are performed usual antibiotic treatment in the form of 3 g of
 cefuroxime and 1.5 g of metronidazole are administered intravenously and the operation is
 performed according to usual guidelines.

 If there is a complicated appendicitis (assessed preoperatively), oral antibiotic treatment
 in the form of 875 mg amoxicillin / 125mg clavulanic acid + 500mg metronidazole x 3 daily for
 3 days are prescribed. The treatment will be independent to the result of PCR determination
 and the culture on the peritoneal fluid.

 The sample containing the peritoneal fluid is sent to the microbiological department, where
 they make the cultivation and resistance determination as well as the PCR. Growth is observed
 on the cultures at 12, 24 and 36 hours and the final result with resistance determination
 after 3 days. The type of bacteria in the samples are recorded. Follow-up is done 30 days
 postoperative, where the patient is contacted by telephone for postoperative complications.
 Complications for appendicitis are typically intraabdominal abscess and wound infection, and
 therefore special attention will be given to these. Wound infections are defined by the
 Centers for Disease Control and Prevention (CDC) surgical site infections (SSI). These and
 any other complications are also recorded according to the Clavien Dindo classification (CD).

 The part of the study that deals with the PCR and culture on the peritoneal fluid is a
 descriptive study to investigate whether the PCR technique can be introduced into the daily
 clinic. The technique has not previously been tested anywhere and therefore it is not
 possible to make any strength calculation on the sensitivity and specificity of the PCR
 method relative to the result of the final culture. From our previous studies it is known
 that at least one third of the patients will be classified as having a complicated
 appendicitis. The inclusion of 100 patients will in our opinion be enough to be able to
 calculate sensitivity and specificity with acceptable safety limits, which can be indicative
 of further studies.

 The other part of the study concerns the change of antibiotic treatment from intravenous to
 oral treatment. The basis for assessing this will be the frequency of any infectious
 complications compared to the frequencies present in the literature. Wound infections by the
 laparoscopic technique is about 3% and intra-abdominal abscess is about 7.5%. The
 investigators will continuously record the frequency of these complications, and if
 deviations from the above occur a detailed review of each case will be made and a decision on
 whether this part of the project can continue or not. The results will also be indicative of
 whether a randomized trial will be necessary.

 Project feasibility All methods are tested. The method of taken samples from the peritoneal
 fluid is tested in another study at the department. The study itself is a feasibility study
 to see if it is safe and possible to use these methods in the clinic. For these reasons, a
 pilot study is not necessary.

 Limitation The exclusion criteria are a limitation. Especially the age limit of 18 years
 courses that the generalizability to patients under 18 is not possible. It is a problem
 because there is a lot of patients with appendicitis under the age of 18.

 It is also a limitation that the study only includes 100 patients. The reason for this is
 that the study is a feasibility study and therefore believed 100 patients is enough to
 conclude if further studies are needed.

 Expected clinical impact The results could be of great importance for future treatment. If it
 is possible to get an answer of the presence of bacteria in the peritoneal fluid within 24
 hours, it is possible to target the antibiotic treatment to the right patients. This is
 important for the single patient but also important for the society because the use of
 antibiotic leads to development of antibiotic resistant bacteria and therefore it is
 important to avoid unnecessary use of antibiotic. Since appendicitis is a very frequent
 disease, research in this area is of great importance as it involves a high number of
 patients and thus a large amount of antibiotics. Especially because it is shown that the
 surgeons overestimate the number of patients with complicated appendicitis.

 In addition to this the oral treatment has the impact that most patients can be treated with
 antibiotics at home. This will have a positive impact for both patient and society.
Inclusion Criteria:

 -  Patients undergoing diagnostic laparoscopy with suspected acute appendicitis

 -  Admitted by the Emergency Department (FAM), at Odense University Hospital (OUH) or
 Svendborg

 -  Gets a laparoscopic appendectomy.

 -  Speaks and understands Danish

 Exclusion Criteria:

 -  Age under 18

 -  Pregnant or breastfeeding

 -  Language difficulties

 -  Sepsis preoperatively assessed via the SIRS criteria leading to preoperatively
 administered antibiotics.

 -  Patients with known gastrointestinal disorders as chronic inflammatory bowel disease
 or previous cancer disease.

 -  Open appendectomy

 -  Other illness than acute appendicitis