Prophylactic metronidazole in appendicectomy: a controlled trial

Consensus Paper on the Surveillance of Surgical Wound Infections

A Surgical Wound Infection (SWI) Task Force was convened by The Society for Hospital Epidemiology of America (SHEA) to evaluate how SWI surveillance should be done and to identify where more information is needed. The Task Force reached consensus in the following areas. The Centers for Disease Control (CDC) definitions of SWI should be used for routine surveillance because of their current widespread acceptance and reproducibility. The CDC definitions have been clarified in an accompanying article (“Report From the CDC”). Direct observation of wounds and traditional infection control surveillance techniques are acceptable methods of case finding for hospitalized patients. The optimal method for case finding postdischarge or after outpatient surgery is unknown at this time. SWI rates should be stratified by surgical wound class plus a measure of patient susceptibility to infection, such as the American Society of Anesthesiology (ASA) class, and duration of surgery Surgeon-specific SWI rates should be calculated and reported to individual surgeons.

Open appendectomy for pediatric ruptured appendicitis: a historical clinical review of the prophylaxis of wound infection and postoperative intra-abdominal abscess

BACKGROUND

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

METHODS

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.

RESULTS

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).

CONCLUSION

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.

Monitoring patient safety in health care: building the case for surrogate measures

BACKGROUND

Objective measurements are notably lacking for many adverse events in health care. A new approach to monitoring such events is based on the experience in measuring hospital-associated infections.

DEVELOPING OBJECTIVE AND UNIVERSAL MEASURES

An essential tenet of the current goal of surveillance-focusing only on rigorously confirmed adverse events-is neither necessary nor achievable across the entire health care system. Efforts should be directed instead to creating objective measures of quality of care and of outcomes that can be used by all health care facilities. Adopting objective measures would be easier if health care was open to surrogate measures of important outcomes. Surrogate measures of interest for infection surveillance are used to identify objective, readily ascertained events that are sufficiently correlated with infections to provide useful information about organizations' infection rates. For example, the surgical site infection rate following coronary artery bypass appears to correlate closely enough with the proportion of patients who receive extended courses of inpatient antibiotics to be a useful indicator of a hospital's outcomes for the procedure.

CONCLUSION

Developing clinically relevant process or surrogate measures that clinicians would use to improve patient outcomes is essential. These measures could be relevant not only to hospital-acquired infections but other health care-related adverse events that are relatively common yet require substantial resources to identify.

Antibiotics versus placebo for prevention of postoperative infection after appendicectomy

BACKGROUND

Appendicitis is the most common cause of acute abdominal pain requiring surgical intervention. The cause of appendicitis is unclear and the mechanism of pathogenesis continues to be debated. Despite improved asepsis and surgical techniques, postoperative complications, such as wound infection and intraabdominal abscess, still account for a significant morbidity. Several studies implicate that postoperative infections are reduced by administration of antimicrobial regimes.

OBJECTIVES

This review evaluated the use of antibiotics compared to placebo or no treatment in patients undergoing appendectomy. Will these patients benefit from antimicrobial prophylaxis? The outcomes were described according to the nature of the appendix, as either simple appendicitis (including the non-infectious stage) and complicated appendicitis. The efficacy of different antibiotic regimens were not evaluated.

SEARCH STRATEGY

We searched The Cochrane Central Register of Controlled Trials (Cochrane Library 2005 issue 1); Pubmed ; EMBASE; and the Cochrane Colorectal Cancer Group Specialised Register (April 2005). In addition, we manually searched the reference lists of the primary identified trials.

SELECTION CRITERIA

We evaluated Randomised Controlled Trials (RCTs) and Controlled Clinical Trials (CCTs) in which any antibiotic regime were compared to placebo in patients suspected of having appendicitis, and undergoing appendectomy. Both studies on children and adults were reviewed. The outcome measures of the studies were: Wound infection, intra abdominal abscess, length of stay in hospital, and mortality.

DATA COLLECTION AND ANALYSIS

Eligibility and trial quality were assessed, recorded and cross-checked by two reviewers.

MAIN RESULTS

Forty-five studies including 9576 patients were included in this review. The overall result is that the use of antibiotics is superior to placebo for preventing wound infection and intraabdominal abscess, with no apparent difference in the nature of the removed appendix. Studies exclusively on children and studies examining topical application reported results in favour to the above, although the results were not significant.

AUTHORS' CONCLUSIONS

Antibiotic prophylaxis is effective in the prevention of postoperative complications in appendectomised patients, whether the administration is given pre-, peri- or post-operatively, and could be considered for routine in emergency appendectomies.

Antibiotics versus placebo for prevention of postoperative infection after appendicectomy

BACKGROUND

Appendicitis is the most common cause of acute abdominal pain requiring surgical intervention. The cause of appendicitis is unclear and the mechanism of pathogenesis continues to be debated. Despite improved asepsis and surgical techniques, postoperative complications, such as wound infection and intraabdominal abscess, still account for a significant morbidity. Several studies implicate that postoperative infections are reduced by administration of antimicrobial regimes.

OBJECTIVES

The objective of this review is to evaluate the use of antibiotics with placebo or no treatment in patients undergoing appendectomy. Will these patients benefit from antimicrobial prophylaxis? The outcomes are described according to the nature of the appendix, as either simple appendicitis (including the non-infectious stage) and complicated appendicitis. This review do not attempt to compare the effect of different regimens. That clinical question is addressed in another review undertaken by Bleuer 1999.

SEARCH STRATEGY

We searched The Cochrane Controlled Trials Register (Cochrane Library 2002 issue 4); Pubmed, Embase and the Cochrane Colorectal Cancer Group Specialised Register (Up to October 2002). In addition we manually searched the reference lists of the primary identified trials.

SELECTION CRITERIA

We evaluated Randomised Controlled Trials (RCTs) and Controlled Clinical Trials (CCTs) in which any antibiotic regime were compared to placebo in patients suspected of having appendicitis, and undergoing appendectomy. Both studies on children and adults were reviewed. The outcome measures of the studies were: Wound infection, intra abdominal abscess, length of stay in hospital, and mortality.

DATA COLLECTION AND ANALYSIS

Eligibility and trial quality were assessed, recorded and cross-checked by two reviewers.

MAIN RESULTS

Forty-five studies including 9576 patients were included in this review. The overall result is that the use of antibiotics is superior to placebo for preventing wound infection and intraabdominal abscess, with no apparent difference in the nature of the removed appendix. Studies exclusively on children and studies examining topical application reported results in favour to the above although the results were not significant.

REVIEWER'S CONCLUSIONS

Antibiotic prophylaxis is effective in the prevention of postoperative complications in appendectomised patients, whether the administration is given pre-, peri- or post-operatively, and could be considered for routine in emergency appendectomies.

Can Oral Metronidazole Substitute Parenteral Drug Therapy in Acute Appendicitis?: A New Policy in the Management of Simple or Complicated Appendicitis with Localized Peritonitis: A Randomized Controlled Clinical Trial

To demonstrate the efficacy of oral metronidazole (OM) in simple or complicated appendicitis with localized peritonitis, a randomized prospective study was carried out in 1083 patients, ranging in age from 4 to 50 years (mean age, 21.38).

The patients were randomly divided into two groups. The study group (SG) (524 patients) received OM (500 mg for adults, 7–10 mg/kg if less than 15 years) 2–3 hours before operation. The drug was continued 4 to 5 hours after operation, every 8 hours, for three doses if the appendix was mild to severely inflamed. In the case of complicated appendicitis (114 patients), the same dose was given for 3 to 6 days, depending on the absence or presence of pus. Ceftizoxime was administered to the control group (CG) (559 patients) 2 to 3 hours before operation and then postoperatively every 6 hours for three doses if the appendix was mild to severely inflamed. The complicated cases in the CG (120 patients) received a combination of penicillin, chloramphenicol, and gentamicin for 3 to 6 days, depending on the absence or presence of pus.

The serum concentration of metronidazole measured in 43 patients was at bactericidal level in 40 (mean ± SD standard deviation, 10.65 ± 4.89 μg/mL).

The rate of wound infection was not significantly different in the SG and the CG with the same degree of pathology (3.17% vs 2.96% if uncomplicated; 15.78% vs 14.16% if complicated, respectively). Pelvic collection occurred in four adults and one child in the CG with perforated appendicitis (4.16%). The same complication developed in two adults and two children in the SG with perforated appendicitis (3.5%). All six adults and one of the children in the SG had to be re-explored, whereas the remaining two children responded to conservative management (OM and gentamicin). In uncomplicated cases, hospital stay and hospital charge were both almost the same in both groups. However, length of hospitalization was nearly 1 day shorter and hospital cost per day was about 30 per cent less in complicated cases in the SG as compared with the CG.

Conclusively, OM may not only substitute parenteral antibiotics in acute appendicitis as a prophylactic agent, but it may also be used as a cost-effective drug and is more convenient to the patient.

Wound infection rates: the importance of definition and post-discharge wound surveillance

The importance of definition and post-discharge wound surveillance on reported wound infection rates have been studied, using data taken from a prospective, randomized, placebo-controlled, double-blind trial of the effect of whole body disinfection on postoperative wound infection rates. All patients admitted for an elective clean or potentially contaminated surgical procedure over a 32-month period were recruited into the study. Of the 3733 patients recruited, 3466 completed the study. Wound infection (which is defined for this study) is the main outcome that was examined. The effect of careful post-discharge follow-up of patients to look for wound infections was analysed for age, wound type and presence or absence of a drain. Sixty percent of postoperative wound infections occurred after discharge. A rising wound infection rate with increasing age was observed in the in-hospital cohort whereas the incidence of outpatient wound infections declined with age. This finding is attributed to the longer in-hospital stay encountered in patients above 50 years old (median, 3 vs. 5 days, P < 0.00001). Although clean operations had a significantly lower in-hospital infection rate, potentially contaminated procedures had a lower outpatient infection rate. A similar picture was observed in other subgroups of operations including horizontal versus vertical wounds and use of drains. When assessing reported wound infection rates, the definition of wound infection used and the extent of follow-up must be known to enable accurate assessment of the results.

Postdischarge surveillance for nosocomial wound infection: a brief review and commentary

Escalating medical care costs during the last decade have resulted in shorter hospital stays and higher volumes of outpatients surgical procedures. As a result, the proportion of nosocomial surgical wound infections manifesting after discharge will increase. We performed a literature review to assess the current state of the art of postdischarge surveillance for nosocomial wound infection. From 20% to 70% of postoperative surgical site infections do not become apparent until after the patient's discharge, resulting in serious underreporting of true rates. Infections in outpatients are not being identified efficiently. Institutions using self-reporting methods report a low validity for these methods. The Centers for Disease Control and the Joint Commission for the Accreditation of Healthcare Organizations currently have no strong guidelines on the subject. Since valid postdischarge surveillance may become a necessity for a quality infection control program, new national recommendations are needed.

Surgical wound infections occurring in day surgery patients

The occurrence of surgical wound infection in outpatient day surgery has not been extensively studied despite the increasing popularity of this mode of treatment. The present study was conducted to determine the frequency of surgical wound infections in a day surgery population. We randomly selected during a 6-month period 635 (25%) of 2540 patients undergoing a day surgery procedure in which a skin incision was made. The patients were telephoned 1 month after their procedure by an infection control practitioner. Infection was diagnosed if the patient reported that (1) their physician had made a diagnosis of a wound infection or (2) pus was or had been issuing from the wound. Of the 515 patients contacted, 72% had undergone a clean and 28% a clean-contaminated procedure. Patient risk factors for infection were almost completely absent in our day surgery patients. Twenty-six wound infections were diagnosed, 19 of which were identified by physicians' diagnosis and 7 by patient description, for a rate of 5.05%. Two patients required hospitalization for their infections, and 14 were treated with antibiotics. The clean wound infection rates were 4.62%, less than half the infection rate seen in our patients undergoing inpatient surgery at 1 month follow-up by the same surveillance technique. We conclude that day surgery infection rates are much lower than inpatient surgery infection rates at our facility, probably because of a relative absence of risk factors in the day surgery patients.

Combined topical and systemic antibiotic prophylaxis in acute appendicitis

Two hundred forty-six patients with acute appendicitis were randomly assigned to one of two groups. One group of 120 patients received systemic clindamycin preoperatively. Another group of 126 patients received, in addition to systemic clindamycin, a solution of topical ampicillin applied to subcutaneous tissues. No differences were found in the characteristics of the two groups. Combined prophylaxis with clindamycin and ampicillin significantly reduced wound infection to 4%, compared with clindamycin alone (p less than 0.02). A decrease in the surgical wound infection rate in the group treated with clindamycin and ampicillin was mainly observed in patients with advanced (gangrenous and perforated) appendicitis (p less than 0.05). A significant decrease in wound infection rates in patients with positive culture results was also found. We conclude that prophylaxis with a combination of systemic clindamycin and topical ampicillin solution, when compared with clindamycin alone, more effectively prevents wound infection after emergency appendectomy, especially in patients with serious wound contamination.

Antibiotic prophylaxis in acute nonperforated appendicitis. The Danish Multicenter Study Group III

In a prospective, block-randomized, multicenter study, the safety and efficacy of cefoxitin in preoperative prophylaxis were studied. 1735 patients undergoing appendectomy were evaluable, and half of these patients received 2 g of cefoxitin before undergoing operation. The patients were divided into three groups: patients with a normal appendix, patients with an acutely inflamed appendix, and patients with a gangrenous appendix. The study showed for each group a significant reduction of the incidence of wound infection in patients receiving prophylaxis. However, intra-abdominal abscess formation was not influenced by preoperative antibiotic prophylaxis. Consequently, routine preoperative prophylaxis is recommended before appendectomy.

Timing of prophylactic antibiotics in abdominal surgery: trial of a pre-operative versus an intra-operative first dose

When prophylactic antibiotics are used in abdominal surgery it is customary to give the first dose before the operation. Whilst intra-operative antibiotics may be effective in elective surgery, there may be an advantage to starting pre-operatively when there is already an infective focus such as appendicitis. Antibiotics started pre-operatively (group P) have been compared with antibiotics started after initial abdominal exploration (group T). Three intravenous doses of 500 mg metronidazole plus 1 g cephazolin were given in a randomized, double-blind study of 700 emergency and elective high-risk abdominal operations. Antibiotic plasma concentrations at the end of the operation were significantly lower in group P but lay well within the therapeutic range. Wound infection rates, which included minor and delayed infections, were similar in both groups (group P, 57 of 342, 16.7 per cent; group T, 55 of 358, 15.4 per cent; 95 per cent confidence intervals for the difference being -4.1 to +6.7 per cent. In appendicitis, wound infection rates were 12.1 and 13.9 per cent for groups P and T respectively. However, non-fatal deep sepsis was more common in group P (nine cases) than in group T (two cases) (chi 2 = 4.9, P less than 0.05). Postoperative infection was twice as common in obese patients whose body mass index (BMI) was greater than or equal to 26 (39 of 132, 30 per cent) than in thin patients whose BMI was less than 24 (41 of 288, 14 per cent; chi 2 = 13.8, P less than 0.001). This study failed to show any advantage to starting antibiotics pre-operatively, even in appendicitis.

Preventing wound infection after appendicectomy: a review

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.

Survey of antibiotic prophylaxis in gastrointestinal surgery in Scotland--5 years on

The results of a 5-year follow-up survey of the use of prophylactic antibiotics in gastrointestinal surgery in Scotland are reported. There have been significant increases in the routine use of prophylactic antibiotics during elective cholecystectomy (21% to 53% of surgeons; P less than 0.001) and appendicectomy (49% to 79% of surgeons; P less than 0.001). In addition a substantial number of surgeons used prophylactic antibiotics in selected high risk patients undergoing biliary tract surgery and gastroduodenal surgery.

Influence of surgeons' experience on postoperative sepsis

A prospective study was performed on 635 patients with appendicitis operated on by 7 trainees and 119 patients operated on by 6 senior surgeons with more than 8 years of surgical experience. In patients with normal appendices, postoperative sepsis was extremely low. For early and late appendicitis, the infection rates of the trainees decreased as experiences accumulated, but they were still higher than that of the senior surgeons. The difference in infection rates in acute appendicitis did not reach statistical significance between any of the training stages and between the various stages and the rate of the senior surgeons. The differences in infection rates in late appendicitis between stage 1 and stage 3 was significant, as was the difference in infection rates between stage 1 and the infection rate of the senior surgeons. Therefore, we have concluded that overall, the limited experience of trainees is related to the rate of postoperative sepsis in late appendicitis, although the infection rates of individual trainees vary a lot.

Surgical wound infections documented after hospital discharge

Shorter lengths of hospitalization may result in more surgical wound infections being documented after hospital discharge. The current investigation analyzed 1644 surgical procedures performed over a 3-month period, and documented surgical wound infections both before and for 1 month after hospital discharge. Physician and patient questionnaires were used. One hundred eight infections were noted, of which 50 (46%) were seen after hospital discharge by either the patient or the surgeon. Rates of infection were 5.2%, 7.5%, and 7.5% for clean, clean-contaminated, and contaminated-dirty categories, respectively. Had postdischarge surveillance not been used, rates would have appeared to be 2.5%, 6.5%, and 6.8% for the same surgical classes. Infections following clean and clean-contaminated procedures were more likely to be noticed after hospital discharge. Excluding those that were patient-documented, wound infection rates would have been 4.2% (clean), 6.3% (clean-contaminated) and 6.8% (contaminated-dirty). Postdischarge surveillance is imperative to meaningfully document true rates of surgical wound infection, inasmuch as increasing numbers are likely to occur only after patients leave the hospital.

Cefotetan compared with gentamicin and tinidazole in acute abdominal surgery

In a prospective randomised trial 190 consecutive admissions undergoing emergency abdominal surgery were allocated to receive a 24-h peri-operative prophylactic regime of either cefotetan or gentamicin and tinidazole. Wound sepsis developed in 14 patients in each group and one patient in each group developed intra-abdominal abscess. Nine patients in the cefotetan group and 10 patients in the gentamicin and tinidazole group died within 1 month of surgery. The death of one patient in each group was directly related to sepsis. Sixty-five per cent of aerobes isolated at operation were sensitive to cefotetan and 62% sensitive to gentamicin. The in vitro anaerobic cover of tinidazole was complete, whereas 13% of anaerobes isolated at operation were resistant to cefotetan. Anaerobes, predominantly Bacteroides fragilis, were isolated from six of the 14 infected wounds following cefotetan prophylaxis and two of the 14 infected wounds in the gentamicin and tinidazole group. It is therefore recommended that cefotetan should be combined with a nitroimidazole in patients undergoing emergency colo-rectal procedures.

Antibiotic treatment during surgery for diffuse peritonitis: a prospective randomized study comparing the effects of cefuroxime and of a cefuroxime and metronidazole combination

In a prospective randomized open study of patients operated upon for diffuse peritonitis, the effects of two different antibiotic regimens were evaluated. Cefuroxime given as a single drug (Group I; n = 59) was compared with a combination of cefuroxime and metronidazole (Group II; n = 63). Bacteriological cultures, both aerobic and anaerobic, were obtained peroperatively and in the event of any complication. The antibiotic sensitivities of isolated bacteria, and the serum and tissue concentrations of cefuroxime were determined. Postoperative infectious complications occurred in 22 per cent of Group I patients (cefuroxime), and in 17.5 per cent of Group II (cefuroxime plus metronidazole). The mortality rates were 5 per cent for Group I and 8 per cent for Group II. Tissue concentrations of cefuroxime were well above the MIC (minimal inhibiting concentration) values for most of the bacteria isolated. From a few patients in Group I, however, cultures were obtained with isolates sensitive to metronidazole but resistant to cefuroxime. Our findings suggest that, in the antibiotic treatment of patients operated for diffuse peritonitis, an agent which is primarily effective against aerobic bacteria (but not entirely without effect on anaerobes) is as effective as combination therapy covering both aerobic and anaerobic bacteria.

Systemic metronidazole combined with either topical povidone-iodine or ampicillin in acute appendicitis

One-hundred consecutive patients undergoing appendicectomy either electively or for clinically diagnosed acute appendicitis were studied to examine the difference between the use of topical povidone-iodine (PVP-I) and ampicillin in the wound given at the time of closure. All patients were treated with metronidazole suppositories for 48 h starting at the time of pre-medication in addition to a topical agent. The overall wound infection rate was 14%. If the appendix was histologically normal or inflamed, the rate fell to 10% whereas if gangrenous or perforated it rose to 24%. Sixty-six per cent of the patients with a perforated appendicitis developed a wound infection. There was no significant difference in the wound infection rate between those treated with PVP-I and those with ampicillin. Topical antisepsis using PVP-I is preferable to ampicillin as it abolishes the risk of antibiotic resistance or allergy developing and since it is comparatively more cost-effective.

Prophylactic antibiotics in appendicectomy: a prospective double blind randomized study

Our double blind prospective randomized trial comparing intravenous cefoxitin with rectal metronidazole in appendicectomy reveals both groups to be similar regarding basic data, with no significant difference in the results between the two drugs. Nearly all the wound infections occurred after the patient went home. Most were minor infections and the overall infection rate was 6%. The intravenous route was the more certain but the more expensive. Bacteriology suggests that the same flora were present in the appendiceal wall of normal and acute non-perforated appendices. This would suggest bacteriologically that the same risks exist with non-inflamed appendicectomy as occurs with inflamed non-perforated appendices. These findings support the use of short course prophylaxis in appendicectomy.

A Danish multicenter study: cefoxitin versus ampicillin + metronidazole in perforated appendicitis

A prospective controlled randomized-block multicenter study was carried out in 209 patients undergoing surgery for perforated or ruptured appendicitis. The patients received either cefoxitin or ampicillin + metronidazole for 5 days. The treatment was started peroperatively. In both groups wound infections were found to be less than 10 per cent and no difference could be demonstrated. However cefoxitin was significantly superior to ampicillin + metronidazole in preventing intra-abdominal abscesses (P less than 0.05). Cefoxitin offers a single drug treatment that adequately reduces postoperative infectious complications in patients undergoing surgery for perforated or ruptured appendicitis.

Prophylaxis of postappendicectomy sepsis by metronidazole and cefotaxime; a randomized, prospective and double blind trial

A randomized, prospective and double blind trial was conducted on 308 patients. Thirty-one out of 102 patients receiving metronidazole developed wound infection compared with 13 out of 103 patients receiving cefotaxime and 14 out of 103 patients receiving metronidazole and cefotaxime. The reduction in the wound sepsis by the use of cefotaxime or a combination of metronidazole and cefotaxime was statistically significant when compared with patients who received metronidazole only. For early cases including normal, acutely inflamed and gangrenous appendices, we gave a single dose of antibiotics just before operation. For late cases with perforation and abscess formation, the antibiotics were continued for 5 days. There was no statistical difference in wound infection between patients who received cefotaxime alone and these who received a combination of metronidazole and cefotaxime.

Metronidazole v. cefoxitin in severe appendicitis--a trial to compare a single intraoperative dose of two antibiotics given intravenously

In severe appendicitis, the effect of a single intravenous dose of metronidazole (500 mg) was compared with cefoxitin (1 g). The antibiotics were given by random allocation once the diagnosis had been established at operation. In the metronidazole group, 5 out of 48 patients developed a wound infection whilst in hospital compared with 13 out of 48 in the cefoxitin group (P = 0.036). However, 57% of wound infections became apparent after the patient went home and the overall infection rates were similar. The mean length of postoperative hospital stay was 5.0 days in the metronidazole group and 6.8 days in the cefoxitin group (P = 0.052), but of those who did develop a wound infection, the length of stay was almost double in the cefoxitin group. Anaerobic organisms were cultured from the wound in 7 out of 15 patients who received cefoxitin but in none of 5 patients in the metronidazole group. Whilst metronidazole only delayed the discharge of pus from the wound, it did seem to reduce the severity of infection. Cefoxitin appeared to be less effective, given as a single intravenous injection at a dose of 1 g.

The prevention of postappendicectomy sepsis by metronidazole and cotrimoxazole: a controlled double blind trial

A double-blind, randomized controlled trial was carried out in University Hospital, Kuala Lumpur to study the effect of metronidazole and cotrimoxazole on the incidence of wound infection following appendicectomy from November 1978 to January 1980. Patients were allocated at random into one of four groups: cotrimoxazole injection and placebo suppository, metronidazole suppository and cotrimoxazole injection, metronidazole suppository and placebo injection or placebo suppository and placebo injection. Treatment was started 30 min before operation and continued for 72h. All patients were followed up for 2 weeks and thereafter for one month. A total of 283 patients was finally accepted into the study. Sepsis rates were found to be 27% for the untreated group, 9% for the group receiving metronidazole only, 8% for the group receiving cotrimoxazole injection only and 2.7% for the group receiving both drugs. The study showed that a combination of metronidazole and cotrimoxazole is a regime highly effective for prophylaxis against wound infection following appendicectomy.

Metronidazole and ticarcillin in the prevention of sepsis after appendicectomy

Ticarcillin was compared with metronidazole in the prevention of wound infection after appendicectomy. Two hundred nine patients with a diagnosis of acute appendicitis were admitted to a prospective, randomized study and received 500 mg of metronidazole or 5 g of ticarcillin intravenously before operation. Those patients with gangrenous or perforated appendices received two additional doses of the trial drug at 8 hourly intervals. The overall incidence of wound infections in both the metronidazole and the ticarcillin groups was 9 percent. There were no intraabdominal abscesses. Metronidazole abolished anaerobic wound infections. All the early wound infections (between 2 and 4 days after operation) occurred in patients with gangrenous or perforated appendices. We conclude that ticarcillin is as effective as metronidazole in the prevention of wound infection after appendicectomy, but in high-risk patients, (those with gangrenous or perforated appendices) longer courses of antibiotics should be employed.

Prophylaxis of post-appendicectomy sepsis by metronidazole and ampicillin: a randomized, prospective and double-blind trial

Two hundred and eighty-three patients were admitted to a randomized, prospective and double-blind trial of the effect of the addition of ampicillin to metronidazole in the prophylaxis of post-appendicectomy wound sepsis. Nineteen out of 142 patients in the metronidazole and ampicillin group developed wound sepsis compared with 33 out of 141 patients in the metronidazole group. The difference is statistically significant. Early cases, including normal, acutely inflamed and gangrenous appendices, received 2 doses of antibiotics. In late cases with perforation and abscess formation, the antibiotics were continued for 1 week. The difference in wound infection in each of these 2 subgroups was also statistically significant. The commonest organisms isolated from the appendicular fossa and the infected wounds were Escherichia coli and Bacteroides fragilis.

The prophylactic use of antimicrobials in surgery

During the period August 1976 to June 1982, there were 98 reports of antimicrobial prophylaxis in human surgery that were judged unevaluable. Our review, coupled with that of Chodak and Plaut, identified studies of 126 antibiotic regimens that were considered evaluable and a total of 205 studies considered unevaluable. A decrease in infection rate in antibiotic-treated patients compared to non-antibiotic-treated patients was seen in 120 (95%) of the evaluable regimens. Ninety-nine (79%) of these 120 regimens produced statistically significant reductions in the infection rate (P less than .05, chi 2 analysis). The majority of the antibiotic regimens were tested in procedures that were classified as clean-contaminated. Of the regimens that yielded a statistically significant reduction in infection rate with antimicrobial therapy, in 66 (67%) the agents were used for 24 hours or less. Five regimens were identified in which a higher infection rate occurred in specific patient groups when prophylactic antibiotics were used, but the differences were not statistically significant. In the overwhelming majority of evaluable studies, antibiotics decreased the incidence of surgical infection compared with non-antibiotic groups. The available data also support the effectiveness of short prophylactic antibiotic courses of 24 hours' duration or less. The duration necessary for antibiotic prophylaxis was specifically tested in nine regimens. In all nine, a short course (less than 24 hours) of antibiotic prophylaxis was as effective as longer periods of therapy (24 hours to 5 days) in preventing infection.

A double-blind controlled trial of metronidazole suppositories in children undergoing appendicectomy

A total of 133 children, aged 16 months to 15 years (mean 6.7 years), with presumptive acute appendicitis, was included in a double-blind, placebo-controlled trial of the short-term (72 hour) use of metronidazole suppositories as prophylaxis against post-operative infection. There was no significant difference in the incidence or severity of wound infection or post-operative intra-abdominal sepsis between the metronidazole-treated and placebo groups. It is suggested that intra-rectal metronidazole, when used exclusively, is not sufficient for effective prophylaxis for appendicitis in childhood.

Rational use of antibiotics for perforated appendicitis in childhood

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.

Prophylaxis of infection after appendicectomy: a survey of current surgical practice

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.