The use of antibiotics in general surgery

Comparing optimization criteria in antibiotic allocation protocols

Clinicians prescribing antibiotics in a hospital context follow one of several possible 'treatment protocols'-heuristic rules designed to balance the immediate needs of patients against the long-term threat posed by the evolution of antibiotic resistance and multi-resistant bacteria. Several criteria have been proposed for assessing these protocols; unfortunately, these criteria frequently conflict with one another, each providing a different recommendation as to which treatment protocol is best. Here, we review and compare these optimization criteria. We are able to demonstrate that criteria focused primarily on slowing evolution of resistance are directly antagonistic to patient health both in the short and long term. We provide a new optimization criteria of our own, intended to more meaningfully balance the needs of the future and present. Asymptotic methods allow us to evaluate this criteria and provide insights not readily available through the numerical methods used previously in the literature. When cycling antibiotics, we find an antibiotic switching time which proves close to optimal across a wide range of modelling assumptions.

Antibiotic prophylaxis for prevention of postoperative wound infection in adults undergoing open elective inguinal or femoral hernia repair

BACKGROUND

Inguinal or femoral hernia is a tissue protrusion in the groin region and has a cumulative incidence of 27% in adult men and of 3% in adult women. As most hernias become symptomatic over time, groin hernia repair is one of the most frequently performed surgical procedures worldwide. This type of surgery is considered 'clean' surgery with wound infection rates expected to be lower than 5%. For clean surgical procedures, antibiotic prophylaxis is not generally recommended. However after the introduction of mesh-based hernia repair and the publication of studies that have high wound infection rates the debate as to whether antibiotic prophylaxis is required to prevent postoperative wound infections started again.

OBJECTIVES

To determine the effectiveness of antibiotic prophylaxis in reducing postoperative (superficial and deep) wound infections in elective open inguinal and femoral hernia repair.

SEARCH METHODS

We searched several electronic databases: Cochrane Registry of Studies Online, MEDLINE Ovid, Embase Ovid, Scopus and Science Citation Index (search performed on 12 November 2019). We also searched two trial registers and the reference list of included studies.

SELECTION CRITERIA

We included randomised controlled trials comparing any type of antibiotic prophylaxis versus placebo or no treatment for preventing postoperative wound infections in adults undergoing inguinal or femoral open hernia repair surgery (tissue repair and mesh repair).

DATA COLLECTION AND ANALYSIS

Two review authors independently selected studies, extracted data and assessed risk of bias. We separately analysed results for two different surgical methods (herniorrhaphy and hernioplasty). Several studies revealed infection rates that were higher than the expected 5% for clean surgery and we therefore divided studies into two subgroups: high infection risk environments (≥ 5% infection rate); and low infection risk environments (< 5% infection rate). We performed meta-analyses with random-effects models. We analysed three outcomes: superficial surgical site infections (SSSI); deep surgical site infections (DSSI); and all postoperative wound infections (SSSI + DSSI).

MAIN RESULTS

In this review update we identified and included 10 new studies. In total, we included 27 studies with 8308 participants in this review. It is uncertain whether antibiotic prophylaxis as compared to placebo (or no treatment) prevents all types of postoperative wound infections after herniorrhaphy surgery (risk ratio (RR) 0.86, 95% confidence interval (CI) 0.56 to 1.33; 5 studies, 1865 participants; very low quality evidence). Subgroup analysis did not change these results. We could not perform meta-analyses for SSSI or DSSI as these outcomes were not reported separately. Twenty-two studies related to hernioplasty surgery (total of 6443 participants) and we analysed three outcomes: SSSI; DSSI; SSSI + DSSI. Within the low infection risk environment subgroup, antibiotic prophylaxis as compared to placebo probably makes little or no difference for the outcomes 'prevention of all wound infections' (RR 0.71, 95% CI 0.44 to 1.14; moderate-quality evidence) and 'prevention of SSSI' (RR 0.71, 95% CI 0.44 to 1.17, moderate-quality evidence). Within the high infection risk environment subgroup it is uncertain whether antibiotic prophylaxis reduces all types of wound infections (RR 0.58, 95% CI 0.43 to 0.77, very low quality evidence) or SSSI (RR 0.56, 95% CI 0.41 to 0.77, very low quality evidence). When combining participants from both subgroups, antibiotic prophylaxis as compared to placebo probably reduces the risk of all types of wound infections (RR 0.61, 95% CI 0.48 to 0.78) and SSSI (RR 0.60, 95% CI 0.46 to 0.78; moderate-quality evidence). Antibiotic prophylaxis as compared to placebo probably makes little or no difference in reducing the risk of postoperative DSSI (RR 0.65, 95% CI 0.26 to 1.65; moderate-quality evidence), both in a low infection risk environment (RR 0.67, 95% CI 0.11 to 4.13; moderate-quality evidence) and in the high infection risk environment (RR 0.64, 95% CI 0.22 to 1.89; low-quality evidence).

AUTHORS' CONCLUSIONS

Evidence of very low quality shows that it is uncertain whether antibiotic prophylaxis reduces the risk of postoperative wound infections after herniorrhaphy surgery. Evidence of moderate quality shows that antibiotic prophylaxis probably makes little or no difference in preventing wound infections (i.e. all wound infections, SSSI or DSSI) after hernioplasty surgery in a low infection risk environment. Evidence of low quality shows that antibiotic prophylaxis in a high-risk environment may reduce the risk of all wound infections and SSSI, while evidence of very low quality shows that it is uncertain whether antibiotic prophylaxis reduces DSSI after hernioplasty surgery.

Role of prophylactic antibiotics in open inguinal hernia repair: a randomised study

To study the role of prophylactic antibiotics in open inguinal hernia repair. A total of 200 patients were included, they were randomised in two groups. Group 1 was given prophylactic dose of inj amoxy-clav while group 2 was given placebo only. Results were compared and Data analysed using the Chi-square test. Complications in both the groups were compared. Rate of serous discharge and seroma formation was 1% and 22% respectively in group 1 while 2% and 26% in group 2 also the rate of erythema and stitch abscess were 1% and none in group 1 and 2% and 1% in group 2 respectively. On statistical analysis these differences were not significant. Addition of prophylactic antibiotics in elective open inguinal hernia repair has no significant benefit over placebo although larger studies are required to prepare some uniform guidelines.

Antibiotic prophylaxis for hernia repair

BACKGROUND

The use of antibiotic prophylaxis for hernia repair is currently a controversial issue given the disparity among study results in this area.

OBJECTIVES

The objective of this systematic review was to clarify the effectiveness of antibiotic prophylaxis in reducing postoperative wound infection rates in elective open inguinal hernia repair.

SEARCH METHODS

We searched the Cochrane Colorectal Cancer Group specialized register, by crossing the terms herni* and inguinal or groin and the terms antimicr* or antibiot* , as free text and MeSH terms. A similar search were performed in Medline using the following terms: #1 antibiotic* OR antimicrob* OR anti infecti* OR antiinfecti*; #2 prophyla* OR prevent*; #3 #1 AND #2; #4 clean AND (surgery OR tech* OR proced*); #5 herni*; #6 (wound infection) AND #4; #7 #3 AND (#4 or #5 or #6). National Research Register, ISI-Web, DARE, Scirus, TRIPDATABASE, NHS EED, reference list of the included studies and web of clinical trials register (www.controlled-trials.com and clinicaltrials.gov) were checked to identify further studies.

SELECTION CRITERIA

Only randomised clinical trials were included.

DATA COLLECTION AND ANALYSIS

In the present review, we searched for eligible trials in October 2011. This revealed four new included trials, so seventeen trials are included in the meta-analysis. Eleven of them used prosthetic material for hernia repair (hernioplasty) whereas the remaining studies did not (herniorrhaphy). Pooled and subgroup analysis were conducted depending on whether prosthetic material was or not used. A fixed effects model was used in the analysis.

MAIN RESULTS

The total number of patients included was 7843 (prophylaxis group: 4703, control group: 3140). Overall infection rates were 3.1% and 4.5% in the prophylaxis and control groups, respectively (OR 0.64, 95% CI 0.50 - 0.82). The subgroup of patients with herniorrhaphy had infection rates of 3.5% and 4.9% in the prophylaxis and control groups, respectively (OR 0.71, 95% CI 0.51 - 1.00). The subgroup of patients with hernioplasty had infection rates of 2.4% and 4.2% in the prophylaxis and control groups, respectively (OR 0.56, 95% CI 0.38 - 0.81).

AUTHORS' CONCLUSIONS

Based on the results of this systematic review the administration of antibiotic prophylaxis for elective inguinal hernia repair cannot be universally recommended. Neither can the administration be recommended against when high rates of wound infection are observed.

Antibiotic prophylaxis for hernia repair

BACKGROUND

The use of antibiotic prophylaxis for hernia repair is currently a controversial issue given the disparity among study results in this area.

OBJECTIVES

The objective of this systematic review was to clarify the effectiveness of antibiotic prophylaxis in reducing postoperative wound infection rates in elective open inguinal hernia repair.

SEARCH STRATEGY

In the present review, we searched for eligible trials in august 2006, using the search terms below. This revealed four new included trials (total of twelve). We searched the Cochrane Colorectal Cancer Group specialized register, by crossing the terms herni* and inguinal or groin and the terms antimicr* or antibiot* , as free text and MeSH terms. A similar search were performed in Medline and Embase was conducted using the following terms: #1 antibiotic* or antimicrob* or anti infecti* or antiinfecti*; #2 prophyla* or prevent*; #3 #1 and #2; #4 clean and (surgery or tech* or proced*); #5 herni*; #6 (wound infection) and #4; #7 #3 and (#4 or #5 or #6). Reference lists of the included studies were checked to identify additional studies.

SELECTION CRITERIA

Only randomized clinical trials were included.

DATA COLLECTION AND ANALYSIS

Twelve randomized clinical trials were identified. Six of them used prosthetic material for hernia repair (hernioplasty) whereas the remaining studies did not (herniorraphy). Pooled and subgroup analysis were conducted depending on whether prosthetic material was or not used. A random effects model was used in the analysis.

MAIN RESULTS

The total number of patients included was 6705 (treatment group: 4128, control group: 2577). Overall infection rates were 2.9% and 3.9% in the prophylaxis and control groups, respectively (OR 0.64, 95%CI 0.48 - 0.85). The subgroup of patients with herniorrhaphy had infection rates of 3.5% and 4.9% in the prophylaxis and control groups, respectively (OR 0.71, 95% CI 0.51 - 1.00). The subgroup of patients with hernioplasty had infection rates of 1.4% and 2.9% in the prophylaxis and control groups, respectively (OR 0.48, 95% CI 0.27 - 0.85).

AUTHORS' CONCLUSIONS

Based on the results of this meta-analysis the administration of antibiotic prophylaxis for elective inguinal hernia repair cannot be universally recommended. Nevertheless, its administration cannot either be recommended against when high rates of wound infection are observed.

Duration of antimicrobial prophylaxis in patients undergoing hepatectomy: a prospective randomized controlled trial using flomoxef

OBJECTIVES

Although the usefulness of antimicrobial prophylaxis for clean-contaminated surgery has been recognized, only a few randomized controlled studies on the duration of administration after hepatectomy have been performed. We investigated the duration of antimicrobial prophylaxis after hepatectomy.

METHODS

The subjects were 180 patients who underwent hepatectomy without reconstruction of the biliary or intestinal tract between April 2003 and March 2006 at our department. The patients were randomly allocated to groups to be treated with flomoxef sodium as antimicrobial prophylaxis for 2 days (89 patients) or 5 days (91 patients), including the operation day. The presence or absence of systemic inflammatory response syndrome (SIRS) and infections was investigated.

RESULTS

No significant differences were noted in patient background between the two groups. Infections occurred in seven and six patients in the 2 day and 5 day treatment groups (7.9% and 6.6%), respectively, showing no significant difference between the two groups. No significant difference was noted when the cases were divided into surgical site infections and remote infections. The positive rate of SIRS was significantly higher in the 2 day treatment group than in the 5 day treatment group on days 2 and 3 after surgery. The risk factors in patients who developed infections were blood loss, operation time and the complication of biliary fistula.

CONCLUSIONS

Two day administration of flomoxef sodium may be sufficient for antimicrobial prophylaxis after hepatectomy. However, when SIRS is positive on post-operative day 2, and induction of liver failure is of concern, it may be safer to continue antimicrobial drug administration until SIRS is eliminated.

Antimicrobial prophylaxis in clean surgery with special focus on inguinal hernia repair with mesh

Until recently, antimicrobial prophylaxis was thought to be unnecessary for clean surgery except when a foreign body is implanted or the presence of infection poses a significant risk to patients. However, the results of several trials support extending the administration of antimicrobial prophylaxis to other types of clean surgery such as inguinal hernia repair or breast surgery. A recent Cochrane meta-analysis concluded that antimicrobial prophylaxis for inguinal hernia repair with or without mesh cannot be recommended or discarded. Resolution of this problem is important because inguinal hernia repair with mesh is one of the most common procedures in general surgery, and antibiotic consumption for preventive purposes is becoming a serious problem due to the risk of contribution to development of bacterial resistance and the significant increase in healthcare costs. This review will document clinical trials and meta-analyses on clean surgery, and will focus on inguinal hernia repair with mesh.

Elective inguinal hernia repair with mesh: is there a need for antibiotic prophylaxis?--A review

Although it is widely accepted that antibiotic prophylaxis is indicated in elective mesh repair of inguinal hernia, the evidence for its value has been controversial. A recent Cochrane meta-analysis showed that there is insufficient data overall to demonstrate a clear advantage of prophylaxis and illustrated the classic problem in evidence-based medicine where a lack of evidence in support of an intervention may be interpreted as a reason not to implement it. This review of the literature evaluates the evidence for the effectiveness of intravenous antibiotics as prophylaxis in inguinal hernia repair with mesh. Pubmed and Embase searches revealed seven trials of antibiotic prophylaxis in mesh repair of inguinal hernia. The quality of the evidence and the limitations of the seven trials are discussed. Analysis of these seven trials adds to the Cochrane meta-analysis of Sanchez-Manuel and Seco-Gil. Only two of the trials support the use of antibiotic prophylaxis, and those were the only double-blind randomized controlled trials reviewed. In evidence-based medicine the absence of evidence in clear support of an intervention (as in this review, where only two of the seven trials support the use of antibiotic prophylaxis) may be taken as reason not to implement the intervention. It is possible, however, that what is needed to clarify the issue are further randomized controlled trials, rigorously performed and recruiting significantly larger numbers of patients.

Antibiotic prophylaxis for hernia repair

BACKGROUND

The use of antibiotic prophylaxis for hernia repair is currently a controversial issue given the disparity among study results in this area.

OBJECTIVES

The objective of this systematic review was to clarify the effectiveness of antibiotic prophylaxis in reducing postoperative wound infection rates in elective open inguinal hernia repair.

SEARCH STRATEGY

Searches in the Cochrane Colorectal Cancer Group specialized register were conducted crossing the terms herni* and inguinal or groin and the terms antimicr* or antibiot* , as free text and MeSH terms. A similar search in Medline (WebSPIRS from Silver Platter, January/1966 to March/2004) and Embase (1976 to December/2003) was conducted using the following terms: #1 antibiotic* or antimicrob* or anti infecti* or antiinfecti*; #2 prophyla* or prevent*; #3 #1 and #2; #4 clean and (surgery or tech* or proced*); #5 herni*; #6 (wound infection) and #4; #7 #3 and (#4 or #5 or #6). Reference lists of the included studies were checked to identify additional studies.

SELECTION CRITERIA

Only randomized clinical trials were included.

DATA COLLECTION AND ANALYSIS

Eight randomized clinical trials were identified. Three of them used prosthetic material for hernia repair (hernioplasty) whereas the remaining studies did not (herniorraphy). Pooled and subgroup analysis were conducted depending on whether prosthetic material was or not used. A random effects model was used in the analysis.

MAIN RESULTS

The total number of patients included was 2907 (treatment group: 1421, control group: 1486). Overall infection rates were 2.88% and 4.3% in the prophylaxis and control groups, respectively (OR 0.65, 95%CI 0.35 - 1.21). The subgroup of patients with herniorrhaphy had infection rates of 3.78% and 4.87% in the prophylaxis and control groups, respectively (OR 0.84, 95%CI 0.53 - 1.34). The subgroup of patients with hernioplasty had infection rates of 1.2% and 3,3% in the prophylaxis and control groups, respectively (OR 0.28, 95%CI 0.02 - 3.14).

REVIEWERS' CONCLUSIONS

Based on the results of this meta-analysis, there was no clear evidence that routine administration of antibiotic prophylaxis for elective inguinal hernia repair reduced infection rates.

Analyzing Prophylactic Antibiotic Administration in Procedures Lasting More than Pour Hours: Are Published Guidelines Being Followed?

Published guidelines for surgical antibiotic prophylaxis recommend that an appropriately selected and administered antibiotic should be repeated in a timely manner in lengthy procedures. To assess concordance with published guidelines we reviewed the prophylactic antibiotic usage in procedures lasting more than 4 hours at a 500-bed university hospital. The records of 300 procedures longer than 4 hours in duration from the gastrointestinal, neurosurgery, and vascular surgery services were retrospectively reviewed. Analysis was confined to the usage of antibiotics in a prophylactic setting. Using a liberal interpretation of the American College of Surgeons, Centers for Disease Control and Prevention, Surgical Infection Society, and Medical Letter Guidelines each case was evaluated for the appropriateness of the antibiotic selection, the interval between the first dose and the skin incision, and the timeliness of repeat dosing. Twenty-five patients (8.3%) did not receive any antibiotic coverage at all. One hundred ninety cases (63.3%) received the correct antibiotic, but only 96 (32%) received it in a timely manner before surgery. Nine patients (3%) in 300 cases received repeat doses at the correct time for the entire duration of the surgery in complete compliance with the published guidelines. We conclude that antibiotic prophylaxis of lengthy procedures is rarely in accordance with published guidelines.

Preventing antimicrobial-resistant bacterial infections in surgical patients

BACKGROUND

The Centers for Disease Control and Prevention (CDC) has identified the control of antimicrobial resistance as an important effort to reduce the morbidity and mortality associated with health care. Methods to prevent these infections in surgical patients have rarely been addressed specifically.

METHODS

The peer-reviewed literature and published guidelines were examined to identify proven or suggested techniques for controlling antimicrobial resistance that would be particularly relevant to surgeons and the surgical patient population.

RESULTS

A multi-step approach to the prevention of antimicrobial-resistant infections in surgical patients was developed. This program consists of four major strategies: Infection prevention, effective diagnosis and treatment of infection, optimal antibiotic utilization, and the prevention of transmission.

CONCLUSION

The control of antimicrobial resistance in bacteria is an important objective for all physicians, including surgeons. An approach to attain this goal in surgical populations is outlined. Further research will be needed to determine the value of these practices and to develop newer, even more effective interventions.

Standardized patient care guidelines reduce infectious morbidity in appendectomy patients

BACKGROUND

Surgical wound infection and intra-abdominal abscess remain common infectious complications after appendectomy, especially in the setting of a perforated or gangrenous appendix. We therefore developed a clinical protocol for the management of appendicitis to decrease postoperative infectious complications.

METHODS

Between January 1, 1999, and December 31, 1999, 206 patients with appendicitis were treated on protocol. Retrospectively, the charts were reviewed for all protocol patients as well as for 232 patients with appendicitis treated in the year prior to protocol initiation. Data were collected on surgical wound infections and intra-abdominal abscesses.

RESULTS

There were significantly fewer infectious complications in the protocol group than in the nonprotocol group (20 [9%] versus 8 [4%]; P <0.05). In patients with a perforated or gangrenous appendix, the infectious complication rate was reduced from 33% to 13% (P <0.05).

CONCLUSIONS

The incidence of infectious complications after appendectomy can be significantly reduced with a standardized approach to antibiotic therapy and wound management.

Postoperative antibiotic prophylaxis in mandibular fractures: A preliminary randomized, double-blind, and placebo-controlled clinical study

PURPOSE

This study evaluated the difference between the effect of a 5-day postoperative course of oral antibiotics and a placebo on the incidence of postoperative infection in uncomplicated fractures of the mandible.

PATIENTS AND METHODS

A prospective, randomized, double-blind clinical study using a placebo control was carried out. Thirty patients were randomly assigned into 2 groups: group 1 (14 patients) and group 2 (16 patients). Each group received penicillin G, 2 million U intravenously, every 4 hours through the preoperative period, intraoperative period, and for 12 hours postoperatively. Group 1 then received penicillin VK, 500 mg every 6 hours for 5 days. Group 2 received oral placebo using the same schedule for the same duration as group 1. The patients were than evaluated for evidence of infection 1, 2, 4, and 6 weeks postoperatively.

RESULTS

Two of 14 patients in group 1 (14.3%) and 2 of 16 patients in group 2 (12.5%) developed infections. No statistically significant difference in the incidence of infection was noted between the groups.

CONCLUSIONS

In this preliminary study, the use of postoperative oral antibiotics in uncomplicated fractures of the mandible had no benefit in reducing the incidence of infections.

Gangrenous and perforated appendicitis: a meta-analytic study of 2532 patients indicates that the incision should be closed primarily

BACKGROUND

Surgical incisions after appendectomy for complicated (gangrenous or perforated) acute appendicitis are often managed with delayed closure (DC) rather than primary closure (PC). This study synthesizes the results of other studies in the surgical literature and supports the routine use of PC.

METHODS

Studies dealing with complicated appendicitis were reviewed to assess the results of PC in comparison with DC. The rate of incision (wound) infection in groups of patients managed by PC and DC were compared with the use of a statistical technique that defined the probability of expected results by incorporating data derived from all of the various study groups.

RESULTS

Of the 2532 patients who had been treated for complicated appendicitis and who were assessed, 1724 patients underwent PC and 808 patients underwent DC. The rate of incision infection was 4.7% and 4.6% in the PC and DC groups, respectively. With a 95% confidence interval, there was no demonstrable difference between the 2 types of operative site management (P < .01).

CONCLUSIONS

PC of the skin and subcutaneous tissue after appendectomy for gangrenous or perforated appendicitis, combined with the use of antibiotic therapy in the perioperative period, is not associated with an increased risk of incision infection when compared with DC.

Perioperative antibiotic prophylaxis in abdominal surgery for hernia repair: retrospective study of 1,524 consecutive patients

In the surgical units of our Division, from January 1979 to December 1989, the infection rate in surgical groin hernia repair was much higher than expected, in comparison to other reports in the literature. In order to evaluate if correct preoperative antibiotic prophylaxis could decrease the incidence of postoperative infections (wound, urinary and respiratory tract) after abdominal wall hernia repair surgery, a total of 1,524 consecutive patients undergoing this type of procedure were reviewed between January 1990 and December 1996. The patients were divided in three different groups, according to the antibiotic prophylaxis regimen: i) group A: 606 patients (39.8%) treated with ceftriaxone; ii) group B: 408 patients (26.8%) treated with pefloxacin; and iii) group C: 510 patients (33.4%) treated with different regimens using either cephalosporins or quinolones other than ceftriaxone and pefloxacin. Only 1 surgical wound infection was observed (0.06%). The tolerability was good: no significant side effects related to antibiotic prophylaxis were recorded in our experience. In this study, even though retrospective, single-dose ceftriaxone proved to be a valid and cost-effective choice in antibiotic prophylaxis.

Prospective randomized trial of systemic antibiotics in patients undergoing liver resection

BACKGROUND

Systemic antibiotics are administered frequently after hepatectomy to prevent infective complications, but their effectiveness is uncertain.

METHODS

A total of 127 patients with liver tumours were prospectively randomized into two groups after hepatectomy: in group 1 (62 patients) no antibiotics were given until the appearance of infective complications; in group 2 (65 patients) intravenous cephazolin 1 g every 6 h and gentamicin 80 mg every 8 h were given for 7 days. On the day before surgery all patients received bowel preparation by clear liquid diet and oral antibiotics (neomycin 1 g and erythromycin 1 g, given together in three doses).

RESULTS

The infective complication rate was 23 per cent in both groups (P = 0.95). The hospital costs were higher in group 2 (P < 0.001). Of the group 1 patients, 51 (82 per cent) did not require antibiotic treatment. No patient in either group died after hepatectomy.

CONCLUSION

Postoperative systemic antibiotics cannot prevent infective complications, and their routine use after hepatectomy is unnecessary and costly. The use of antibiotics should be delayed until infective complications and persistent septic symptoms occur.

Antibiotics for the acute abdomen

Antibiotics are only an adjunct to proper surgical therapy for the treatment of the acute abdomen associated with bacterial secondary peritonitis. Upon presentation, all patients require a preoperative dose of antibiotics for prophylaxis against infection of remaining sterile tissues. Patients found intraoperatively to have an established peritoneal infection benefit from an immediate postoperative course of therapeutic antibiotics. A regimen that adequately covers facultative and aerobic gram-negative bacilli and anaerobic organisms is essential. The duration of therapeutic antibiotics is probably best decided on an individual patient basis. The goal of antibiotics is to reduce the concentration of bacteria invading tissues. The pathogens of bacterial peritonitis are influenced by such factors as the patient's pre-existing chronic diseases, state of acute physiologic debilitation, immunocompetence, recent antibiotic use, recent hospitalization, and neutralization of gastric acidity. Intraoperative peritoneal cultures are most useful in patients suspected of having impaired local host defenses. In these patients, all identified organisms, such as Enterococcus or Candida, may be potential pathogens. The common practice of administering empiric and prolonged courses of broad-spectrum antibiotics in patients who manifest persistent signs of inflammation may be more harmful than beneficial. These patients warrant an exhaustive search for extra-abdominal and intraperitoneal sources of new infection. Otherwise, such use of antibiotics may continue to promote the selection of bacteria that are highly resistant to conventional antibiotics and permit the overgrowth of organisms commonly seen with tertiary peritonitis. The best chance of resolving bacterial peritonitis is through early, aggressive surgical management complemented by short courses of potent antibiotics and appropriate physiologic support. Through these efforts, the clinician tries to help the systemic inflammatory response to benefit the host and not become unregulated, result in MOFS, and produce a high mortality.

Prophylactic antibiotics in cataract operations

The rationale for prophylactic antibiotics in cataract operations must be continually reevaluated in light of cost-effectiveness and adverse reactions. The principles learned from wound infections associated with general surgical procedures should be applied to the limited knowledge about the rare event of endophthalmitis. Herein the literature on experimental and clinical wound infections in general surgical procedures is reviewed, with analysis of microbial flora, pathophysiology of wound infections, and pharmacokinetics of antibiotics. Experimental and clinical studies on prophylactic antibiotics to prevent endophthalmitis are reviewed, including information on topically applied antibiotics, chemical antisepsis, and administration of subconjunctival, intracameral, and systemic antibiotics. In addition, the benefits, limitations, and risks of the various types of prophylactic antibiotics are discussed. Because of the limited data on prophylactic antibiotics in cataract operations, providing dogmatic statements is difficult. General recommendations are offered based on the currently available literature, and a stratified approach is suggested based on wound construction and number of anterior segment maneuvers.

Let us shorten antibiotic prophylaxis and therapy in surgery

Excessive duration of antibiotics for prophylaxis and treatment of surgical infection appears to be the principal reason for "inappropriate" administration in current surgical practice. The main factors to blame are the inability of the clinician to distinguish between contamination, infection, and inflammation. Failure to distinguish between contamination and infection is the reason that prophylaxis is unnecessarily carried through into the postoperative phase for prolonged periods. Failure to distinguish between infection and inflammation misguides surgeons to continue antibiotics for unnecessarily long treatment periods. The concept for shortening courses of antibiotic administration is supported by a forum of experts. The majority of experts also favored a trend away from the use of therapeutic courses of fixed duration, by tailoring the duration of administration to the intraoperative findings to shorten treatment courses. Specific recommendations are (1) contamination: single dose prophylaxis (gastroduodenal peptic perforations operated within 12 hours, traumatic enteric perforations operated within 12 hours, peritoneal contamination with bowel contents during elective or emergency procedures, early or phlegmonous appendicitis, or phlegmonous cholecystitis); (2) resectable infection: 24-hour postoperative antibiotics (appendectomy for gangrenous appendicitis, cholecystectomy for gangrenous cholecystitis, bowel resection for ischemic or strangulated "dead" bowel without frank perforation); (3) advanced infection: 48 hours to 5 days, based on operative findings and patient's condition (intra-abdominal infection from diverse sources); (4) severe infection with the source not easily controllable: longer administration periods may be necessary (e.g., infected pancreatic necrosis).

Management of secondary peritonitis

OBJECTIVE

The authors review current definition, classification, scoring, microbiology, inflammatory response, and goals of management of secondary peritonitis.

SUMMARY BACKGROUND DATA

Despite improved diagnostic modalities, potent antibiotics, modern intensive care, and aggressive surgical treatment, up to one third of patients still die of severe secondary peritonitis. Against the background of current understanding of the local and systemic inflammatory response associated with peritonitis, there is growing controversy concerning the optimal antibiotic and operative therapy, intensified by lack of properly conducted randomized studies. In this overview the authors attempt to outline controversies, suggest a practical clinical approach, and highlight issues necessitating further research.

METHODS

The authors review the literature and report their experience.

RESULTS

The emerging concepts concerning antibiotic treatment suggest that less-in terms of the number of drugs and the duration of treatment-is better. The classical single operation for peritonitis, which obliterates the source of infection and purges the peritoneal cavity, may be inadequate for severe forms of peritonitis; for the latter, more aggressive surgical techniques are necessary to decompress increased intra-abdominal pressure and prevent or treat persistent and recurrent infection. The widespread acceptance of the more aggressive and demanding surgical methods has been hampered by the lack of randomized trials and reportedly high associated morbidity rates.

CONCLUSIONS

Sepsis represents the host's systemic inflammatory response to bacterial peritonitis. To improve results, both the initiator and the biologic consequences of the peritoneal infective-inflammatory process should be addressed. The initiator may be better controlled in severe forms of peritonitis by aggressive surgical methods, whereas the search for methods to abort its systemic consequences is continuing.

The role of cefotaxime in the treatment of surgical infections

This study examines the role of cefotaxime in the treatment of both Gram-negative and Gram-positive surgical infections. A dose of 2 g of cefotaxime will sustain peripheral compartment concentrations of 2.6, 3.9, 1.6, and 0.7 micrograms/ml for 6, 8, 10 and 12 h, respectively. Therefore, the proportion of pathogens with a minimal inhibitory concentration (MIC) below the peripheral compartment cefotaxime concentrations was assessed as a measure of therapeutic potential. It was observed that bacterial elimination in infections correlates well with such pharmacodynamic predictions. Therefore, treatment recommendations for surgical infections are based on the following pharmacodynamics. The times above the MIC in the tissue compartment for various pathogens (1988-1994) known to cause surgical infections were: Escherichia coli, 12 h; all pyogenic streptococci, 12 h; pneumococci, 12 h; Haemophilus spp., 12 h; Proteus mirabilis, 12 h; Klebsiella spp., 10.9 h; viridans streptococci, 10.6 h; oxacillin-susceptible, coagulase-negative staphylococci, 9.7 h; Providencia spp., 9.2 h; Clostridium perfringens, 8.6 h; Peptostreptococcus spp., 8 h; oxacillin-susceptible Staphylococcus aureus, 7.3 h; and all S. aureus, 6.8 h. From the examination of pharmacodynamic parameters, cefotaxime appears to be a viable choice for the therapy of surgical infections other than the Gram-negative anaerobes. For those infections, metronidazole with cefotaxime would be preferred.