Patients with complicated appendicitis have an increased risk for postoperative infections. Potential risk factors for postoperative infections through a meta-analysis and retrospective chart review are discussed. A meta-analysis consisting of 35 studies analyzing complicated appendicitis treated with an appendectomy noting at least 1 postoperative infection was performed. A retrospective review was then conducted in patients diagnosed with complicated appendicitis after appendectomy. Of 5326 patients in total, 15.4% developed postoperative infections. Laparoscopic surgery and perioperative hyperoxygenation were found to be protective factors for the development of infection. Retrospectively, 53.2% of patients presented with complicated appendicitis. Patients with complicated appendicitis were more likely to be older in age and have an increased length of stay. Patient demographics, operative time, and comorbid status had no effect on postoperative infection or readmission rate. Physicians should strongly consider minimally invasive techniques to treat all cases of complicated appendicitis irrespective of comorbidities, age, sex, or body mass index.

This is the second update of a Cochrane Review first published in 2015 and last updated in 2018. Appendectomy, the surgical removal of the appendix, is performed primarily for acute appendicitis. Patients who undergo appendectomy for complicated appendicitis, defined as gangrenous or perforated appendicitis, are more likely to suffer postoperative complications. The routine use of abdominal drainage to reduce postoperative complications after appendectomy for complicated appendicitis is controversial.

To assess the safety and efficacy of abdominal drainage to prevent intraperitoneal abscess after appendectomy (irrespective of open or laparoscopic) for complicated appendicitis; to compare the effects of different types of surgical drains; and to evaluate the optimal time for drain removal.

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), Ovid MEDLINE, Ovid Embase, Web of Science, the World Health Organization International Trials Registry Platform, ClinicalTrials.gov, Chinese Biomedical Literature Database, and three trials registers on 24 February 2020, together with reference checking, citation searching, and contact with study authors to identify additional studies.

We included all randomised controlled trials (RCTs) that compared abdominal drainage versus no drainage in people undergoing emergency open or laparoscopic appendectomy for complicated appendicitis. We also included RCTs that compared different types of drains and different schedules for drain removal in people undergoing appendectomy for complicated appendicitis.

We used standard methodological procedures expected by Cochrane. Two review authors independently identified the trials for inclusion, collected the data, and assessed the risk of bias. We used the GRADE approach to assess evidence certainty. We included intraperitoneal abscess as the primary outcome. Secondary outcomes were wound infection, morbidity, mortality, hospital stay, hospital costs, pain, and quality of life.

Use of drain versus no drain We included six RCTs (521 participants) comparing abdominal drainage and no drainage in participants undergoing emergency open appendectomy for complicated appendicitis. The studies were conducted in North America, Asia, and Africa. The majority of participants had perforated appendicitis with local or general peritonitis. All participants received antibiotic regimens after open appendectomy. None of the trials was assessed as at low risk of bias. The evidence is very uncertain regarding the effects of abdominal drainage versus no drainage on intraperitoneal abscess at 30 days (risk ratio (RR) 1.23, 95% confidence interval (CI) 0.47 to 3.21; 5 RCTs; 453 participants; very low-certainty evidence) or wound infection at 30 days (RR 2.01, 95% CI 0.88 to 4.56; 5 RCTs; 478 participants; very low-certainty evidence). There were seven deaths in the drainage group (N = 183) compared to one in the no-drainage group (N = 180), equating to an increase in the risk of 30-day mortality from 0.6% to 2.7% (Peto odds ratio 4.88, 95% CI 1.18 to 20.09; 4 RCTs; 363 participants; low-certainty evidence). Abdominal drainage may increase 30-day overall complication rate (morbidity; RR 6.67, 95% CI 2.13 to 20.87; 1 RCT; 90 participants; low-certainty evidence) and hospital stay by 2.17 days (95% CI 1.76 to 2.58; 3 RCTs; 298 participants; low-certainty evidence) compared to no drainage. The outcomes hospital costs, pain, and quality of life were not reported in any of the included studies. There were no RCTs comparing the use of drain versus no drain in participants undergoing emergency laparoscopic appendectomy for complicated appendicitis. Open drain versus closed drain There were no RCTs comparing open drain versus closed drain for complicated appendicitis. Early versus late drain removal There were no RCTs comparing early versus late drain removal for complicated appendicitis.

The certainty of the currently available evidence is low to very low. The effect of abdominal drainage on the prevention of intraperitoneal abscess or wound infection after open appendectomy is uncertain for patients with complicated appendicitis. The increased rates for overall complication rate and hospital stay for the drainage group compared to the no-drainage group are based on low-certainty evidence. Consequently, there is no evidence for any clinical improvement with the use of abdominal drainage in patients undergoing open appendectomy for complicated appendicitis. The increased risk of mortality with drainage comes from eight deaths observed in just under 400 recruited participants. Larger studies are needed to more reliably determine the effects of drainage on morbidity and mortality outcomes.

Prophylactic, intraabdominal drains have been used to prevent intraabdominal abscess (IAA) after perforated appendicitis. We hypothesized that routine drain placement would reduce the IAA rate in pediatric perforated appendicitis.

A 27-month quality improvement (QI) initiative was conducted: closed-suction, intraabdominal drains were placed intraoperatively in pediatric (age < 18) perforated appendicitis patients. QI patients were compared to controls admitted during the preceding 8 months and following 4 months. The primary outcome was 30-day IAA rate. Univariate and multivariate analyses were performed.

Two hundred seventy QI patients were compared to 109 controls. There was 100% compliance during 21 of 27 months of the QI initiative; only 7 QI patients did not receive drains. IAA occurred in 20.0% of QI patients and 22.9% of control (p = 0.52). After adjustment, the QI initiative was not associated with reduced odds of IAA (OR 0.83, 95% CI 0.48-1.44). Median length of stay was longer in QI patients during the index admission (p = 0.03) and over 30 postoperative days (p = 0.03), but these relationships did not persist after adjustment.

A QI initiative investigating prophylactic, intraabdominal drain placement in perforated appendicitis did not reduce the IAA rate. We recommend against routine drain placement in pediatric perforated appendicitis.

Level III.

The guidelines for the prevention, detection, and management of gastroenterological surgical site infections (SSIs) were published in Japanese by the Japan Society for Surgical Infection in 2018. This is a summary of these guidelines for medical professionals worldwide.

We conducted a systematic review and comprehensive evaluation of the evidence for diagnosis and treatment of gastroenterological SSIs, based on the concepts of the Grading of Recommendations Assessment, Development and Evaluation (GRADE) system. The strength of recommendations was graded and voted using the Delphi method and the nominal group technique. Modifications were made to the guidelines in response to feedback from the general public and relevant medical societies.

There were 44 questions prepared in seven subject areas, for which 51 recommendations were made. The seven subject areas were: definition and etiology, diagnosis, preoperative management, prophylactic antibiotics, intraoperative management, perioperative management, and wound management. According to the GRADE system, we evaluated the body of evidence for each clinical question. Based on the results of the meta-analysis, recommendations were graded using the Delphi method to generate useful information. The final version of the recommendations was published in 2018, in Japanese.

The Japanese Guidelines for the prevention, detection, and management of gastroenterological SSI were published in 2018 to provide useful information for clinicians and improve the clinical outcome of patients.

Appendectomy, the surgical removal of the appendix, is performed primarily for acute appendicitis. Patients who undergo appendectomy for complicated appendicitis, defined as gangrenous or perforated appendicitis, are more likely to suffer from postoperative complications. The routine use of abdominal drainage to reduce postoperative complications after appendectomy for complicated appendicitis is controversial.This is an update of the review first published in 2015.

To assess the safety and efficacy of abdominal drainage to prevent intra-peritoneal abscess after open appendectomy for complicated appendicitis.

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (the Cochrane Library, 2017, Issue 6), Ovid MEDLINE (1946 to 30 June 2017), Ovid Embase (1974 to 30 June 2017), Science Citation Index Expanded (1900 to 30 June 2017), World Health Organization International Clinical Trials Registry Platform (30 June 2017), ClinicalTrials.gov (30 June 2017) and Chinese Biomedical Literature Database (CBM) (1978 to 30 June 2017).

We included all randomised controlled trials (RCTs) that compared abdominal drainage and no drainage in people undergoing emergency open appendectomy for complicated appendicitis.

Two review authors identified the trials for inclusion, collected the data, and assessed the risk of bias independently. We performed the meta-analyses using Review Manager 5. We calculated the risk ratio (RR) for dichotomous outcomes (or a Peto odds ratio for very rare outcomes), and the mean difference (MD) for continuous outcomes with 95% confidence intervals (CI). We used GRADE to rate the quality of evidence.

We included six RCTs (521 participants), comparing abdominal drainage and no drainage in patients undergoing emergency open appendectomy for complicated appendicitis. The studies were conducted in North America, Asia and Africa. The majority of the participants had perforated appendicitis with local or general peritonitis. All participants received antibiotic regimens after open appendectomy. None of the trials was at low risk of bias.There was insufficient evidence to determine the effects of abdominal drainage and no drainage on intra-peritoneal abscess at 14 days (RR 1.23, 95% CI 0.47 to 3.21; 5 RCTs; 453 participants; very low-quality evidence) or for wound infection at 14 days (RR 2.01, 95% CI 0.88 to 4.56; 5 RCTs; 478 participants; very low-quality evidence). The increased risk of 30-day overall complication rate (morbidity) in the drainage group was rated as very low-quality evidence (RR 6.67, 95% CI 2.13 to 20.87; 1 RCT; 90 participants). There were seven deaths in the drainage group (N = 183) compared to one in the no drainage group (N = 180), equating to an increase in the risk of 30-day mortality from 0.6% to 2.7% (Peto odds ratio (OR) 4.88, 95% CI 1.18 to 20.09; 4 RCTs; 363 participants; moderate-quality evidence). There is 'very low-quality' evidence that drainage increases hospital stay compared to the no drainage group by 2.17 days (95% CI 1.76 to 2.58; 3 RCTs; 298 participants).Other outlined outcomes, hospital costs, pain, and quality of life, were not reported in any of the included studies.

The quality of the current evidence is very low. The effect of abdominal drainage on the prevention of intra-peritoneal abscess or wound infection after open appendectomy is uncertain for patients with complicated appendicitis. The increased rates for overall complication rate and hospital stay for the drainage group compared to no drainage group is also subject to great uncertainty. Thus, there is no evidence for any clinical improvement by using abdominal drainage in patients undergoing open appendectomy for complicated appendicitis. The increased risk of mortality with drainage comes from eight deaths observed in just under 400 people recruited to the studies. Larger studies are needed to determine the effects of drainage on morbidity and mortality outcomes more reliably.

Prophylactic use of intra-peritoneal drain is commonly practiced by surgeons in the hope of early detection of complication and reducing mortality and morbidity. The aim of the study was to determine evidence based value of prophylactic drainage of peritoneal cavity in cases of secondary peritonitis and resection and anastomosis of small and large bowel.

One hundred and seventy one (171) cases were included in the study from March 2012-May 2013 that underwent laparotomy for peptic ulcer perforation (PUP), simple and complicated acute appendicitis (appendicular perforation with localized/generalized peritonitis), small bowel obstruction (SBO) and sigmoid volvulus, traumatic and non-traumatic perforation of small and large bowel. Appropriate management was done after resuscitation and investigation. After completion of operation peritoneal cavity was either drained or not drained according operator's preference. They were divided into drain and non-drain groups. Surgical outcome and postoperative complications ≤30 days of operation was noted and compared between two groups.

No significant difference was observed between drained group and non-drained group in terms of age (32.08±15.99 vs. 35.57 ± 16.42 years), Sex (76M: 42F vs. 40M: 13F), weight 50.9 ± 11.75 vs. 48.4 ± 16.1 kg), height (1.6 ± 0.13 vs. 1.5 ± 0.18 Meter), BMI (20 ± 4.7 vs. 20 ± 7.2), ASA score (p= >0.05). However there was significant difference was observed between drained group and non-drained groups in terms of length of hospital stay (9 ± 4 vs 5 ± 3.4 days), operative duration (115.6 ± 41.0 vs. 80 ± 38.1 minutes), infection rates in dirty wound (40.0% vs 12.5%) and overall postoperative complications (35.85% vs16.11%).

Based on these results, present study suggests that prophylactic drainage of peritoneal cavity after gastrointestinal surgery is not necessary as it does not offer additional benefits for the patients undergoing gut surgery. Moreover, it increases operative duration, length of hospital stay and surgical site infection (SSI).

Appendectomy, the surgical removal of the appendix, is performed primarily for acute appendicitis. Patients who undergo appendectomy for complicated appendicitis, defined as gangrenous or perforated appendicitis, are more likely to suffer from postoperative complications. The routine use of abdominal drainage to reduce postoperative complications after appendectomy for complicated appendicitis is controversial.

To assess the safety and efficacy of abdominal drainage to prevent intra-peritoneal abscess after open appendectomy for complicated appendicitis.

We searched The Cochrane Library (Issue 1, 2014), MEDLINE (1950 to February 2014), EMBASE (1974 to February 2014), Science Citation Index Expanded (1900 to February 2014), and Chinese Biomedical Literature Database (CBM) (1978 to February 2014).

We included all randomised controlled trials (RCTs) that compared abdominal drainage and no drainage in patients undergoing emergency open appendectomy for complicated appendicitis.

Two review authors identified the trials for inclusion, collected the data, and assessed the risk of bias independently. We performed the meta-analyses using Review Manager 5. We calculated the risk ratio (RR) for dichotomous outcomes (or a Peto odds ratio for very rare outcomes), and the mean difference (MD) for continuous outcomes with 95% confidence intervals (CI).

We included five trials involving 453 patients with complicated appendicitis who were randomised to the drainage group (n = 228) and the no drainage group (n = 225) after emergency open appendectomies. All of the trials were at a high risk of bias. There were no significant differences between the two groups in the rates of intra-peritoneal abscess or wound infection. The hospital stay was longer in the drainage group than in the no drainage group (MD 2.04 days; 95% CI 1.46 to 2.62) (34.4% increase of an 'average' hospital stay).

The quality of the current evidence is very low. It is not clear whether routine abdominal drainage has any effect on the prevention of intra-peritoneal abscess after open appendectomy for complicated appendicitis. Abdominal drainage after an emergency open appendectomy may be associated with delayed hospital discharge for patients with complicated appendicitis.

To compare the profile of postoperative outcome in secondary peritonitis with sepsis due to complicated appendicitis in two cohorts (drainage vs no-drainage) after appendicectomy in adults in the modern era of effective antibiotics.

A retrospective review of all adult patients who were operated for secondary peritonitis with sepsis due to complicated appendicitis was carried out. Total of 209 patients were identified from May 2005 to April 2009 with operative findings of gangrenous or perforated appendix. The patients were divided into two cohorts, those where prophylactic drainage was established (n = 88) and those where no drain was used (n = 121). Abdominal drain was removed once the drainage ceased or decreased (< 10-20 mL/d in closed system of drainage or when once daily dressing was minimally soaked in open system). Broad spectrum antibiotics to cover the gut flora were started in both cohorts at diagnosis and were stopped once septic features resolved. Peritoneal fluid for aerobic culture and sensitivity were routinely obtained intra operatively; however antibiotic regimens were not changed unless patient failed to respond to the antibiotics based on the institutional protocol. The co-morbidities and their influence on primary end points were noted. Immunocompromised patients, appendicitis complicated by inflammatory bowel disorder and tumors were excluded from the study.

Disease stratification and other demographic features were comparable in both cohorts. There was zero mortality in drainage group while as one patient (0.82%) died in the non-drainage group. The median duration (in days) of hospital stay (6.5 vs 4); antibiotic use (5 vs 3.5); regular parental analgesic use (5 vs 3.5) and paralytic ileus (2.5 vs 2) was more common in the drainage group. Incidence of major wound infection in patients 14 (15.9%) vs 22 (18.18%) and residual intra-abdominal sepsis (inter loop collection/abscess) -7 (8%) vs 13 (10.74%) requiring secondary intervention was not significantly different in drainage and non-drainage cohorts respectively. One patient in the drainage cohort had faecal fistula (1.1%).

The complicated appendicitis in the modern era of antibiotics does not necessitate the use of prophylactic drain placement which at times may even prove counterproductive.

We conducted a 3-decade clinical review of prophylaxis for wound infection and postoperative intra-abdominal abscess after open appendectomy for pediatric ruptured appendicitis.

We reviewed the charts of patients with ruptured appendicitis who underwent open appendectomy performed by the same pediatric surgeon at the Hospital for Sick Children, Toronto, Canada, between 1969 and 2003, inclusive. We evaluated 3 types of prophylaxis: subcutaneous (SC) antibiotic powder, peritoneal wound drain and intravenous (IV) antibiotics. We divided the sample into 4 treatment groups: peritoneal wound drain alone (group 1); peritoneal wound drain, SC antibiotic powder and IV antibiotics (group 2); SC antibiotic powder and IV antibiotics (group 3); and IV antibiotics alone (group 4). We used the χ(2) test with Bonferroni correction for multiple comparisons.

There were 496 patients: 348 (70%) boys and 148 (30%) girls, with a mean age of 7 (range newborn to 17) years. There were 90 (18%) wound infections. Compared with the current standard of practice, IV antibiotics alone (group 4), peritoneal wound drain (group 1) was associated with the lowest number of wound infections (7 [7%], p = 0.023). There were 43 (9%) postoperative intra-abdominal abscesses. Compared with IV antibiotics alone, SC antibiotic powder with IV antibiotics (group 3) was associated with the lowest number of postoperative intra-abdominal abscesses (14 [6%], p = 0.06).

Over a 35-year period of open appendectomy for pediatric ruptured appendicitis, wound infection was least frequent in patients who received prophylactic peritoneal wound drain, and postoperative intra-abdominal abscess was least frequent in those who received prophylactic SC antibiotic powder and IV antibiotics.

Despite the putative advantages conferred by closed-suction drains (CSDs), the widespread utilization of post-operative drains has been questioned due to concerns regarding both efficacy and safety, particularly with respect to the risk of surgical site infection (SSI). Although discipline-specific reports exist delineating risk factors associated with SSI as they relate to the presence of CSDs, there are no broad summary studies to examine this issue in depth.

The pertinent medical literature exploring the relationship between CSDs and SSI across multiple surgical disciplines was reviewed.

Across most surgical disciplines, studies to evaluate the risk of SSI associated with routine post-operative CSD have yielded conflicting results. A few studies do suggest an increased risk of SSI associated with drain placement, but are usually associated with open drainage and not the use of CSDs. No studies whatsoever attribute a decrease in the incidence of SSI (including organ/space SSI) to drain placement.

Until additional, rigorous randomized trials are available to address the issue definitively, we recommend judicious use and prompt, timely removal of CSDs. Given that the evidence is scant and weak to suggest that CSD use is associated with increased risk of SSI, there is no justification for the prolongation of antibiotic prophylaxis to "cover" an indwelling drain.

Placing drains is one the most common procedures following operations in surgical disciplines. The indication for placing a drain is, however, usually based on a traditional belief rather than being evidence-based. This paper presents an overview of the literature regarding the indications and the evidence level for placing drains following operations in visceral, vascular, thoracic and orthopeedic surgery as well as traumatology. In visceral surgery the indications for placing drains could be clarified over the past decades but in other surgical fields the level of evidence needs further investigation and clarification through future studies. The available data suggest that in most cases a prophylactic drainage can be avoided. In addition, drains may lead to increased morbidity and higher treatment costs.

Complicated acute appendicitis is still associated with an increased morbidity. If laparoscopy has been accepted as a valid approach, some questions remain concerning intra-abdominal abscess formation. Routine prophylactic drainage of the abdomen has been proposed. However, this practice remains a matter of debate, poorly validated in the literature. With the present study, we investigated the impact of drainage in laparoscopic appendectomy for complicated appendicitis.

This is a case match study of consecutive patients operated on by laparoscopy in a single institution. One hundred and thirty patients operated for complicated appendicitis (local peritonitis without perforation, with perforation, or with periappendicular abscess) with prophylactic intraperitoneal drainage were matched one by one to 130 patients operated without drainage. Uncomplicated appendicitis and generalized peritonitis were excluded. Primary endpoint was surgical complications and secondary endpoints were transit recovery time and length of hospital stay.

Patients without drain had significantly less overall complications (7.7% vs. 18.5%, p = 0.01). Moreover, the absence of drainage was of significant benefit for transit recovery time (2.5 vs. 3.5 days, p = 0.0068) and length of hospital stay (4.2 vs. 7.3 days, p < 0.0001).

No benefits were observed for prophylactic drainage of the abdominal cavity during emergency laparoscopic treatment of complicated appendicitis. For this reason, this practice may be abandoned.

Abdominal prophylactic drainage in digestive surgery was considered until recently as a dogma. But randomised controlled trials have questioned the routine use of abdominal drain in elective surgery. The aim of this review was to assess the usefulness of abdominal prophylactic drainage according to the concept of evidence-based medicine by analysing published randomised trials and meta-analyses. Levels of evidence vary greatly according to the type of surgery. One can conclude: with a good level of evidence that abdominal drainage has no place following elective cholecystectomy, appendicectomy and colectomy with intraperitoneal anastomosis; that it is perhaps unwarranted (lower level of evidence) following gastroduodenal surgery, pancreatectomy, splenectomy, and rectal surgery; and finally that could be indicated following oesophagectomy and common bile duct surgery (very low level of evidence). Nevertheless, when interpreting these data and evidence-based guidelines we should be consider the limitations of published studies (series coming from very expert teams, selected patients, short series, and elective surgery).

To determine the evidence-based value of prophylactic drainage in gastrointestinal (GI) surgery.

An electronic search of the Medline database from 1966 to 2004 was performed to identify articles comparing prophylactic drainage with no drainage in GI surgery. The studies were reviewed and classified according to their quality of evidence using the grading system proposed by the Oxford Centre for Evidence-based Medicine. Seventeen randomized controlled trials (RCTs) were found for hepato-pancreatico-biliary surgery, none for upper GI tract, and 13 for lower GI tract surgery. If sufficient RCTs were identified, we performed a meta-analysis to characterize the drain effect using the random-effects model.

There is evidence of level 1a that drains do not reduce complications after hepatic, colonic, or rectal resection with primary anastomosis and appendectomy for any stage of appendicitis. Drains were even harmful after hepatic resection in chronic liver disease and appendectomy. In the absence of RCTs, there is a consensus (evidence level 5) about the necessity of prophylactic drainage after esophageal resection and total gastrectomy due to the potential fatal outcome in case of anastomotic and gastric leakage.

Many GI operations can be performed safely without prophylactic drainage. Drains should be omitted after hepatic, colonic, or rectal resection with primary anastomosis and appendectomy for any stage of appendicitis (recommendation grade A), whereas prophylactic drainage remains indicated after esophageal resection and total gastrectomy (recommendation grade D). For many other GI procedures, especially involving the upper GI tract, there is a further demand for well-designed RCTs to clarify the value of prophylactic drainage.

The number of in-hospital deaths in children aged 0 to 14 years from acute appendicitis in England and Wales has fallen from an annual average of 36.2 in 1963 through 1967 to 1.8 in 1993 through 1997, and the case-fatality rate from 1.06 to 0.16 per 1,000 discharges, a reduction of 85%. During these 4 decades, the child population has fallen by 8.5%, and the number of children discharged from the hospital with a diagnosis of acute appendicitis by 63%. These data highlight a trend noted in Scotland in the first 50 years of the 20th century. Approximately three quarters of the fall in the number of deaths from acute appendicitis since 1963 is accounted for by a lower incidence of appendicitis in a slightly reduced child population. A quarter of the fall is caused by a marked decline in the hospital case-fatality rate during the last 30 years, likely to be related to improvements in clinical care. Delay in diagnosis is the main contributory factor in the residual small number of deaths each year. Despite the availability of numerous diagnostic aids, clinical acumen remains a fundamental component of expert management of acute appendicitis in children.

Intra-abdominal abscess remains a significant cause of morbidity following appendicectomy. In children, little emphasis has been placed on the non-invasive management of this complication using antibiotic therapy alone. This study reviews the experience of a paediatric surgical department in managing abscess arising after appendicectomy.

Hospital records of all children undergoing appendicectomy between January 1992 and January 1997 were reviewed retrospectively.

Some 1024 children underwent appendicectomy over a 5-year period. Twenty three patients (2.2 per cent) developed abscesses after appendicectomy. Non-operative management with intravenous or oral antibiotics alone was successful in 21 patients, with complete clinical and radiological resolution of the abscess. Drainage of the septic collection was performed in only two patients: by laparotomy (n=1) and by the transrectal route (n=1).

Antibiotic therapy alone is an efficacious and safe first-line treatment modality in children who develop this complication. Drainage of an abscess developing after appendicectomy is rarely necessary in children.

Acute appendicitis is the commonest nongynaecological surgical problem occurring during pregnancy. Almost 10 year's experience at a large teaching hospital is supplemented with an extensive review of the literature to offer guidelines for diagnosis and management. Symptoms, signs and investigations are unhelpful in diagnosis. The overwhelming message is that because perinatal mortality rises from less than 3% in both uncomplicated appendicitis and negative laparotomy, to 20% in perforated disease, the maxim regarding acute appendicitis--if in doubt, take it out--is never more true than in pregnancy.

An exponential increase in the number of published prospective studies reflects both a continuing interest in, and a lack of consensus on, the optimal prophylaxis of wound sepsis after appendicectomy. Review of the literature over the last 25 years leads us to emphasize both the importance of adequate study size and of stratification of the severity of the sepsis found at operation. For critical comparison of prophylactic regimens the high percentage of wound infections disclosed after discharge from hospital must be taken into account. Antibiotics reduce the frequency of wound sepsis and although low wound sepsis rates have been reported with systemic antibiotics active against only anaerobes, the cumulative evidence favours a spectrum of antibacterial activity against both aerobic and anaerobic organisms. Topical antiseptics have no significant effect but topical antibiotics are beneficial. Wide variations in outcome for similar antibiotic regimens reflect the importance of technical factors in determining the frequency of wound sepsis.

The efficacy of a single 500 mg intravenous intra-operative dose of metronidazole in the prevention of postoperative wound infection, following appendicectomy for acute mural appendicitis, was studied in a prospective randomized placebo controlled trial. Fourteen of the 96 patients (14.6%) in the metronidazole group and 13 of the 94 in the placebo group (13.8%) developed postoperative wound infection. Late sepsis was noted in 4 out of the 96 patients in the metronidazole group and in one of the 94 patients in the placebo group. This study suggests that a single intra-operative dose of metronidazole dose not reduce the incidence of postoperative wound infection following appendicectomy for acute mural appendicitis.

This is a prospective and randomized study of 100 patients with acute appendicitis who were less than 10 years old, in which four different antibiotic regimens commonly in use against gram-negative and anaerobic bacteria were compared in terms of postoperative septic complications. The antibiotics were begun immediately preoperatively and continued for five days. Ten percent of the patients developed infection complications, with 4% requiring further surgery. The best results were obtained with cefoxitin (4% of infection), metronidazole plus amikacin and latamoxef (8%), while the regimen of clindamycin plus amikacin was associated with the greatest number of complications (20%). On analyzing the main microbiologic findings of the study, we conclude that some sort of antibiotic treatment is indicated in all types of appendicitis, due to the occult presence of bacteria in the peritoneal cavity, even without clinical evidence of gangrene or perforation. Further, we emphasize the significance of Streptococcus faecalis as being responsible, along with Escherichia coli and Bacteroides fragilis, for serious postoperative complications.

A prospective, randomized, and double-blind study was conducted with 864 patients operated on for appendicitis. In early cases, including normal and acute appendicitis, one dose of antibiotic was given. The rate of postappendectomy septic complications in patients who received cefotaxime, cefoperazone, or moxalactam was very low (about 3%), and there was no statistical difference between the drugs. For late cases, including gangrenous and perforated appendicitis, the antibiotics were continued for 5 days. Moxalactam decreased significantly the septic complications in these patients when compared with the other two drugs. It is safe, free from serious toxic side effects, and more convenient and easier to administer than combination antibiotic therapy. The main disadvantage of moxalactam is its high cost, but this has to be balanced against the savings in nursing time, the cost of monitoring renal function and serum level when aminoglycosides are used, and the reduced usage and manipulation of infusion sets.

Gangrenous and perforated appendicitis was reviewed in 300 pediatric patients. Those with only gangrene generally had a benign course regardless of whether antibiotic therapy was used. However, patients with local perforation or generalized peritonitis had a high incidence of infective complications if they were not treated with antibiotics. Children treated with ampicillin, gentamicin, and clindamycin had markedly fewer wound infections and abscesses and were able to tolerate a diet and go home sooner than those receiving ampicillin and/or gentamicin.

Two hundred seventeen patients were admitted to a randomized and prospective trial of the use of topical hydrogen peroxide prophylactically against wound infection after appendectomy through a gridiron incision. One hundred nine patients received topical hydrogen peroxide and 108 patients were in the control group. There was no statistically significant difference in the wound infection rates in the two groups. Risk factors found to be associated with a significantly higher wound infection rate were (1) age greater than 40 years, (2) duration of symptoms of over 36 hours, (3) generalized guarding, tenderness or rebound, (4) state of the appendix at operation, (5) serous or purulent peritoneal effusion, (6) subjective difficulty of operation as assessed by the surgeons, and (7) positive bacterial culture from the appendicular fossa.

Two hundred and eighty questionnaires were sent to junior surgical staff throughout England inquiring about their use of systemic antibiotic prophylaxis, topical antibacterial agents, and surgical drainage in appendicectomy. One hundred and seventy-five (63%) replies were received from 81 of the 87 hospitals included in the survey. Prophylactic systemic antibiotics were used by 78 surgeons (46%) when operating on a normal appendix but by 168 (99%) when the organ had perforated. Most surgeons started antibiotics before operation, but proportionately fewer did so when the appendix was gangrenous or perforated. Patients with severe contamination tended to receive longer courses of antibiotics, although the duration of administration varied considerably. Metronidazole was included in over 95% of all the prophylactic regimens and was often combined with other drugs when the appendix was gangrenous and perforated. Topical antibacterial agents were applied to the wound routinely by only 45 surgeons (26%), although 106 (61%) used them sometimes. Povidone-iodine was the agent most commonly used. Only 98 surgeons (56%) ever drained appendicectomy wounds, while 135 (77%) sometimes drained the peritoneal cavity. Evidence suggests that present methods of giving systemic antibiotic prophylaxis should continue, but that topical agents and surgical drainage are perhaps unnecessary when surgeons are confident of the efficacy of the systemic treatment used.

Bone samples were taken at orthopaedic surgery from 12 patients, who had been treated with 2 doses of 750 mg cefuroxime by intravenous infusion. After grinding, extraction and assay by the agar diffusion method the levels of cefuroxime ranged between 0.4--1.9 micrograms/g bone. Using an electrophoretic method followed by microbiological assay, higher levels of cefuroxime were measured, possibly because of a diminution in the binding capacity of the bone.

A prospective randomised trial was carried out on 263 patients admitted for appendicectomy. In those patients with normal or inflamed appendix only, wound sepsis occurred in five (5%) of the 96 patients receiving metronidazole compared with seven (7%) of the 91 controls. In patients with gangrenous or perforated appendices, however, 15 of the 32 patients (47%) receiving ampicillin and five (16%) of 31 patients receiving metronidazole developed a wound infection (p less than 0.025). Therapeutic courses of metronidazole significantly reduced wound sepsis rate in those with gangrenous or perforated appendices. Together with another antibiotic it should form part of the management of such patients, but antibiotics are unlikely to reduce further the low rate of wound infection in patients with normal or inflamed appendices.

One hundred patients undergoing appendicectomy through a right iliac fossa incision were randomized to receive normal saline or 500 mg metronidazole as an intravenous infusion during the operation. One patient in the saline group developed an erythematous rash. There were 13 wound infections (as defined by the discharge of pus), 12 (out of 51) in the saline group and 1 (out of 49) in the metronidazole group. Bacteroides spp. were frequently cultured from the lumen of removed appendices and from pus obtained from infected wounds. This work supports the value of metronidazole but suggests that a single-dose regimen is adequate for prophylaxis.

A review of the indications for, and technique of, abdominal drainage is presented. An analysis is made of the physical characteristics of the commonly used types of drains. Evidence is presented that abdominal drains, although sometimes life-saving, are potentially harmfully and should be used only when a clear indication is present. When drainage is employed, it should be of the most efficient, closed type, and the drain should be removed at the earliest safe time after operation.

One hundred and three consecutive patients undergoing appendicectomy for perforated appendicitis were randomly allocated either to have an intraperitoneal drain inserted or not. The results of this trial lend no support to the advocates of drainage.

Consecutive patients undergoing emergency appendectomy (283) or urgent cholecystectomy (51) were prospectively studied for the development of post-operative incisional or peritoneal sepsis. Severity of the original peritoneal infection was carefully recorded, while use of a Penrose dam to drain the peritoneum was randomized according to pre-assigned hospital number. Both aerobic and anaerobic cultures were taken from the abdomen at the time of operation as well as from all postoperative infectious foci. Results demonstrated no essential differences in incidence of wound and peritoneal infection following appendectomy for simple or suppurative appendicitis (187) or following cholecystectomy for acute cholecystitis (51). However, with gangrenous or perforative appendicitis (94), incisional and intra-abdominal infection rates were 43% and 45%, respectively, when a drain was used; yet only 29 and 13%, respectively, without a drain. These latter differences were significant (p < 0.001). In addition, intra-abdominal abscesses were three times as likely to drain through the incision than along any tract provided by the rubber conduit. Cultures revealed that hospital pathogens accounted for a greater proportion of wound and peritoneal sepsis after cholecystectomy and appendectomy for simple or suppurative appendicitis if a drain had been inserted than if managed otherwise. By contrast, a mixed bacterial flora was responsible for most infections following appendectomy for gangrenous or perforated appendicitis, irrespective as to use of a drain.

A randomized controlled trial in 374 patients requiring emergency appendicectomy to determine the value of topical ampicillin and an antiseptic solution of chlorhexidine and cetyl trimethyl ammonium bromide (Savlon) in preventing wound infection is reported. The application of 1 g of ampicillin powder to the wound significantly reduced wound infection in perforated appendicitis, but not in unperforated appendicitis. Wound irrigation with 1% cetyl trimethyl ammonium bromide was ineffective in preventing wound infection in all grades of appendicitis. When wound contamination is difficult to avoid, as in perforated appendicitis, topical ampicillin should be used to reduce the rate of wound infection.

The course of 200 patients who recently underwent appendectomy at UCLA for acute appendicitis has been reviewed to determine the efficacy of preoperative systemic antibiotic prophylaxis in reducing septic morbidity after surgery. Among those with nonperforated appendicitis who were given gentamycin and clindamycin preoperatively, a reduction of infection rate from 10.2 to 5.3 per cent was found when compared with patients who received no antibiotics.

After gastro-intestinal operations wound infection is usually caused by the inoculation of bacteria present within the intestinal tract into the incision during the surgical procedure. In theory, wound sepsis may be minimized by the following methods: (a) avoiding intestinal contamination of the incision; (b) altering the normal flora of the intestinal tract by adding oral antimicrobials to bowel preparation; (c) using topical or systemic prophylactic antibiotic administration for certain high-risk patients. The relative importance of these methods of prophylaxis is described.

The value of extraperitoneal wound drainage and a 3-day course of prophylactic systemic cephaloridine used both separately and together have been assessed in a prospective controlled randomized trial involving 246 patients undergoing appendicectomy at the Leicester Royal Infirmary. Extraperitoneal wound drainage was shown to reduce significantly the incidence of postoperative wound infection in patients with a gangrenous or perforated appendix (P less than 0-025). Prophylactic cephaloridine significantly reduced the overall incidence of wound infection (P less than 0-02) and was also effective when the appendix was gangrenous or perforated (P less than 0-01). A highly significant reduction in wound infection was achieved when the appendix was gangrenous or perforated by the addition of wound drainage to the antibiotic regimen (P less than 0-001).

The duration of antibiotic therapy for peritonitis is commonly decided on an empirical basis. There is obvious advantage in determining the shortest, yet most effective, period for such drug therapy. This study is a comparison of short-course and long-course antibiotic administration following periotonitis produced by experimental rupture of the rabbit appendix.

The prophylactic use of a single dose of lincomycin in 100 patients undergoing appendicectomy reduced the incidence of postoperative wound infection from 17 to 6 per cent compared with a similar group of control patients. There was no correlation with the histological finding in the appendix, but patients with perforated appendicitis were excluded from the study. Bacteriological examination of the appendix area before surgery showed that Bacteroides fragilis and Escherichia coli were the organisms most frequently isolated. The majority of wound infections were due to B. fragilis, either alone or in association with aerobic organisms, but infection due to E. coli and Staphylococcus aureus also occurred. Systemic antibiotic therapy can successfully reduce the complications following appendicectomy but it is necessary to use a compound with activity against anaerobic organisms.

The frequency of non-clostridial anaerobic infection was studied in 95 patients who had undergone acute appendicectomy: 49 received prophylactic metronidazole and 46 received placebo. Anaerobic infection did not develop in any of the metronidazole-treated patients, but infections did develop in nine (19%) of the 46 controls. Metronidazole is conveniently administered by suppository to patients who cannot take oral drugs. Five patients with intra-abdominal infections caused by non-clostridial anaerobes were successfully treated with metronidazole.

Ninety-six wound infections due to Bacteroides fragilis occurring after intestinal surgery are described. Most infections followed appendicectomy or colectomy for diverticulitis. B. fragilis was isolated in pure growth from 47 per cent of infections, and in mixed culture the other common bacteria were Klebsiella spp., Escherichia coli and Enterobacter spp. Fifty-three per cent of the infections responded rapidly to either non-specific measures or antibiotic therapy, but 47 per cent of patients developed complications, usually abscess formation. The successful isolation of bacteroides from clinical material requires special precautions. The specimen for bacteriological examination must be sent to the laboratory in a transport medium which maintains an anaerobic environment and the culture techniques must include a selective agar for the isolation of anaerobic bacteria. The role of antibiotic therapy in preventing postoperative wound infection after intestinal surgery is discussed. Bacteroides has an unusualy pattern of antibiotic susceptibility and it is essential that an effective antibiotic such as lincomycin is included in the treatment of infection originating from the intestinal tract.