Prophylactic use of cephazolin against wound sepsis after cholecystectomy

What Is the Ideal Duration for Surgical Antibiotic Prophylaxis?

Background: Surgical antibiotic prophylaxis practice became common in the 1970s and has since become almost universal. The earliest articles used three doses over 12 hours with the first being administered before the start of the operation. Conclusions: The duration of prophylaxis has varied widely in practice over time, but an increasing body of evidence has supported shorter durations, most recently with recommendations in influential guidelines to avoid administration after the incision is closed.

CIRSE Clinical Practice Manual

Background

Interventional radiology (IR) has come a long way to a nowadays UEMS-CESMA endorsed clinical specialty. Over the last decades IR became an essential part of modern medicine, delivering minimally invasive patient-focused care.

Purpose

To provide principles for delivering high quality of care in IR.

Methods

Systematic description of clinical skills, principles of practice, organizational standards and infrastructure needed for the provision of professional IR services.

Results

There are IR procedures for almost all body parts and organs, covering a broad range of medical conditions. In many cases IR procedures are the mainstay of therapy, e.g. in the treatment of hepatocellular carcinoma. In parallel the specialty moved from the delivery of a procedure towards taking care for a patient’s condition with the interventional radiologists taking ultimate responsibility for the patient’s outcomes.

Conclusions

The evolution from a technical specialty to a clinical specialty goes along with changing demands on how clinical care in IR is provided. The CIRSE Clinical Practice Manual provides interventional radiologist with a starting point for developing his or her IR practice as a clinician.

Perioperative antibiotic prophylaxis in elective surgeries in Iran

BACKGROUND

The use of antibiotic prior to surgery is widely accepted. The WHO has recommended the use of ATC/DDD (Anatomical Therapeutic Chemical / Defined Daily Dose) for the analysis of drug utilization. The aims of the present study are 1) to analyze the assessment of prophylactic antibiotic usage prior to surgery, 2) to assess the drug administration based on antibiograms and 3) to compare the results with the national and international standards.

METHODS

The present study used ATC/DDD, in a retrospective manner. Cefazolin, ceftazidime, gentamicin, ciprofloxacin, metronidazole, vancomycin, imipenem and penicillin G from 21st March to 21st June 2011 were analyzed in a hospital. Out of 516 medical records, 384 patients had received prophylactic antibiotics.

RESULTS

In comparison, the orthopaedic ward had used more antibiotics. The results showed that antibiotics were not selected based on the antibiogram antibiotic programs. Patients in the age range of 20-30 years were the most recipients of the antibiotics. Men had received more antibiotic in comparison with women. About 75% (384 out of 516) of patients in the study received antibiotics as prophylaxis. Cefazolin was the most frequently prescribed antibiotic.

CONCLUSION

Our findings showed differences in comparison with national and international studies, but insignificant differences. Data on in-hospital antibiotic usage are varying widely not only due to different antibiotic policies but also due to different methods of mesurement. These differences make the comparison difficult.

Antibiotic prophylaxis for patients undergoing elective laparoscopic cholecystectomy

BACKGROUND

Cholecystectomy is a common surgical procedure. In the open cholecystectomy area, antibiotic prophylaxis showed beneficial effects, but it is not known if its benefits and harms are similar in laparoscopic cholecystectomy. Some clinical trials suggest that antibiotic prophylaxis may not be necessary in laparoscopic cholecystectomy.

OBJECTIVES

To assess the beneficial and harmful effects of antibiotic prophylaxis versus placebo or no prophylaxis for patients undergoing elective laparoscopic cholecystectomy.

SEARCH STRATEGY

We searched the The Cochrane Hepato-Biliary Group Controlled Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library (Issue 3, 2010), MEDLINE (1985 to August 2010), EMBASE (1985 to August 2010), SCI-EXPANDED (1985 to August 2010), LILACS (1988 to August 2010) as well as reference lists of relevant articles.

SELECTION CRITERIA

Randomised clinical trials comparing antibiotic prophylaxis versus placebo or no prophylaxis in patients undergoing elective laparoscopic cholecystectomy.

DATA COLLECTION AND ANALYSIS

Our outcome measures were all-cause mortality, surgical site infections, extra-abdominal infections, adverse events, and quality of life. All outcome measures were confined to within hospitalisation or 30 days after discharge. We summarised the outcome measures by reporting odds ratios and 95% confidence intervals (CI), using both the fixed-effect and the random-effects models.

MAIN RESULTS

We included eleven randomised clinical trials with 1664 participants who were mostly at low anaesthetic risk, low frequency of co-morbidities, low risk of conversion to open surgery, and low risk of infectious complications. None of the trials had low risk of bias. We found no statistically significant differences between antibiotic prophylaxis and no prophylaxis in the proportion of surgical site infections (odds ratio (OR) 0.87, 95% CI 0.49 to 1.54) or extra-abdominal infections (OR 0.77, 95% CI 0.41 to 1.46). Heterogeneity was not statistically significant.

AUTHORS' CONCLUSIONS

This systematic review shows that there is not sufficient evidence to support or refute the use of antibiotic prophylaxis to reduce surgical site infection and global infections in patients with low risk of anaesthetic complications, co-morbidities, conversion to open surgery, and infectious complications, and undergoing elective laparoscopic cholecystectomy. Larger randomised clinical trials with intention-to-treat analysis and patients also at high risk of conversion to open surgery are needed.

Antibiotic Prophylaxis in Interventional Radiology—Anything New?

Every interventional procedure can result in infective complications. Generally the incidence is low; however, with newer and more aggressive techniques the infection risk is more prevalent and can result in serious adverse outcomes to our patients. Antibiotic prophylaxis has become commonplace; however, there is little controlled data to underpin our regimens and most choices are based on surgical practice and anecdotal evidence. The rise of antibiotic resistance and treatment of many immunocompromised patients further compounds the difficulties faced. The purpose of this article was to examine the evidence that is presented regarding antibiotic prophylaxis in interventional radiology and highlight how we integrate this into our daily practice. In particular we will focus on evolving procedures and techniques that are associated with a high incidence of infection.

Biliary tract infections: a guide to drug treatment

Initial therapy of acute cholecystitis and cholangitis is directed towards general support of the patient, including fluid and electrolyte replacement, correction of metabolic imbalances and antibacterial therapy. Factors affecting the efficacy of antibacterial therapy include the activity of the agent against the common biliary tract pathogens and pharmacokinetic properties such as tissue distribution and the ratio of concentration in both bile and serum to the minimum inhibitory concentration for the expected micro-organism. Antimicrobial therapy is usually empirical. Initial therapy should cover the Enterobacteriaceae, in particular Escherichia coli. Activity against enterococci is not required since their pathogenicity in biliary tract infections remains unclear. Coverage of anaerobes, in particular Bacteroides spp., is warranted in patients with previous bile duct-bowel anastomosis, in the elderly and in patients in serious clinical condition. In patients with acute cholecystitis or cholangitis of moderate clinical severity, monotherapy with a ureidopenicillin--mezlocillin or piperacillin--is at least as effective as the combination of ampicillin plus aminoglycoside. In severely ill patients with septicaemia, an antibacterial combination is preferable. Therapy with aminoglycosides, mostly for Pseudomonas aeruginosa-related infections, should not exceed a few days because the risk of nephrotoxicity seems to be increased during cholestasis. Relief of biliary obstruction is mandatory, even if there is clinical improvement with conservative therapy, because cholangitis is most likely to recur with continued obstruction. Emergency invasive therapy is reserved for patients who fail to show a clinical response to antibacterial therapy within the first 36 to 48 hours or for those who deteriorate after an initial clinical improvement. Immediate surgery is indicated for gangrenous cholecystitis and perforation with peritonitis. Long-term administration of antibacterials is required for recurrent cholangitis, as seen in bile duct-bowel anastomosis. Oral cotrimoxazole (trimethoprim/sulfamethoxazole) is the preferred agent. Wound infection rates after biliary tract surgery can be significantly reduced by preoperative administration of prophylactic antibacterials. Newer generation beta-lactams have not proven to be of greater benefit than older agents such as cefuroxime or cefazolin. Antibacterial prophylaxis before endoscopic retrograde cholangiopancreatography (ERCP) should be reserved for patients with obstructive jaundice, since the risk of infectious complications seems to be strongly associated with this clinical condition. Failure to achieve full biliary drainage is the most important factor in predicting septicaemia, and prophylaxis should be prolonged until the bile duct is unobstructed. Piperacillin, cefazolin, cefuroxime, cefotaxime and ciprofloxacin are effective for this indication.

Single- versus multiple-dose antimicrobial prophylaxis for major surgery: a systematic review

BACKGROUND

Single-dose antimicrobial prophylaxis for major surgery is a widely accepted principle; recommendations have been based on laboratory studies and numerous clinical trials published in the last 25 years. In practice, single-dose prophylaxis has not been universally accepted and multiple-dose regimens are still used in some centres. Moreover, the principle has recently been challenged by the results of an Australian study of vascular surgery. The aim of this current systematic review is to determine the overall efficacy of single versus multiple-dose antimicrobial prophylaxis for major surgery and across surgical disciplines.

METHODS

Relevant studies were identified in the medical literature using the MEDLINE database and other search strategies. Trials included in the review were prospective and randomized, had the same antimicrobial in each treatment arm and were published in English. Rates of postoperative surgical site infections (SSI) were extracted, 2 x 2 tables prepared and odds ratios (OR) [with 95% confidence intervals (95% CI)] calculated. Data were then combined using fixed and random effects models to provide an overall figure. In this context, a high value for the combined OR, with 95% CI > 1.0, indicates superiority of multiple-dose regimens and a low OR, with 95% CI < 1.0, suggests the opposite. A combined OR close to 1.0, with narrow 95% CI straddling 1.0, indicates no clear advantage of one regimen over another. Further subgroup analyses were also performed.

RESULTS

Combined OR by both fixed (1.06, 95% CI, 0.89-1.25) and random effects (1.04, 95% CI, 0.86-1.25) models indicated no clear advantage of either single or multiple-dose regimens in preventing SSI. Likewise, subgroup analysis showed no statistically significant differences associated with type of antimicrobial used (beta-lactam vs other), blinded wound assessment, length of the multiple-dose arm (> 24 h vs 24 h or less) or type of surgery (obstetric and gynaecological vs other).

CONCLUSIONS

Continued use of single-dose antimicrobial prophylaxis for major surgery is recommended. Further studies are required, especially in previously neglected surgical disciplines.

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.

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).

Prescribing practice and cost of antibacterial prophylaxis for surgery at a US Veteran Affairs hospital

This study retrospectively compared the actual drug-related cost of antibacterial prophylaxis for specific operative procedures with the theoretical costs based on recommendations published in Medical Letter on Drugs and Therapeutics, the Surgical Infection Society, and those of the chiefs of each surgical subspecialty at our institution. We identified all patients who received in intravenous bacterial for prophylaxis before a clean or clean-contaminated operation between 1st January and 30th September 1993, using the medical centre's computerised information system. The information included comprehensive surgical case histories, and pharmacy and microbiology records. Only those operations in which recommendations for surgical prophylaxis were present in all 3 guidelines were included. The outcome measures were antibacterial-related costs (drug acquisition and administration costs), the number of antibacterial doses dispensed, and choice of antibacterial agents. During the study period, 3,322 operations were performed, 2,993 of which were excluded. Thus, 329 patients undergoing operations in 6 subspecialties were included in the analysis. The actual mean cost per patient significantly exceeded the projected costs using Medical Letter Consultants' and Surgical Infection Society guidelines for all 6 subspecialties [mean excess cost per patient: $US49.04 and $US34.95, respectively (1994 values)] and institutional guidelines for 4 of the 6 subspecialties (mean excess cost per patient: $US24.36). The actual mean number of doses per patient significantly exceeded those projected using Medical Letter Consultants' and Surgical Infection Society guidelines for all 6 subspecialties (mean excess number of doses per patient: 6.0 and 4.0, respectively) and institutional guidelines for 4 of the 6 subspecialties (mean excess number of doses per patient: 2.9). The choice of antibacterial was appropriate in approximately 90% of cases. We conclude that the practice of antibacterial prophylaxis for specific operative procedures performed by 6 subspecialties is not in accordance with institutional or published guidelines, and the excess cost is primarily a result of prolonged duration of antibacterial prophylaxis.

Raising the outcome standards for conventional open cholecystectomy

BACKGROUND

Postcholecystectomy length of stay declined after the introduction of laparoscopy in 1987. Technology deserves some credit for reducing iatrogenic trauma. However, the improved outcome primarily resulted from setting higher surgical standards. What goals were (and are) achievable with the conventional "open" technique?

METHODS

One surgeon performed 160 consecutive open cholecystectomies from 1983 to 1987. The patients averaged 46 years of age (range 13 to 100), 62% were female, and 20% presented acutely. Five (3.1%) had common bile duct exploration. Each patient was prepared to accept early discharge. Prompt ambulation followed minimal tissue handling and use of long-acting local anesthesia. Enteral feeding at 300 kcal plus 12 g AAs/ hour began immediately, with swallowed air and potential excess removed automatically by efficient more proximal aspiration.

RESULTS

160 patients were discharged the next day, 158 of 160 (99%) without receiving any narcotics. They absorbed (on average) 3,350 kcal plus 130 g AAs the initial 8 to 16 hours. Serum branched-chain amino acids (BCAA) levels rose above basal within 4 hours. Three patients (1.9%) were readmitted. One (0.6%) had a sterile biloma drained percutaneously. A single acute cholecystitis patient developed sepsis (0.6%), a subphrenic abscess that resolved after drainage. The sole mortality (0.6%) was caused suddenly 27 days postoperatively by a pulmonary embolus.

CONCLUSIONS

Laparoscopy is a valuable surgical tool whose actual incremental benefits are yet to be determined. Shorter length of stay after cholecystectomy may primarily reflect the altered expectations and overall improved surgical performance associated with this innovation.

Antibiotic prophylaxis and tourniquet application in podiatric surgery

The use of prophylactic antibiosis in podiatric surgery is common, especially in patients undergoing endoprosthetic procedures, major arthrodeses, lengthy procedures, or in immunocompromised patients. The goal of prophylaxis is to prevent infection. For this to occur, there must be an adequate concentration of the antimicrobial agent in the tissue at the time of the incision. Historically, prophylaxis has consisted of intravenous administration of 1 gm. of cefazolin, 30 to 60 minutes prior to surgery. Cefazolin concentrations in the medial eminence of the first metatarsal were measured in patients undergoing bunionectomy procedures where pneumatic ankle tourniquets were used for hemostasis. The goal of this study was to determine if the current standards of prophylactic antibiotic administration provide adequate bone levels of cefazolin to effectively inhibit potential infection-causing pathogens.

Comparison of cefotaxime plus metronidazole versus cefoxitin for prevention of wound infection after abdominal surgery

In a randomized prospective stratified trial consisting of 1010 patients undergoing abdominal surgery involving the viscera, the efficacy of cefotaxime plus metronidazole was compared to cefoxitin for preventing wound infection. The efficacy of a single dose of antibiotics versus three doses over 24 hours was also evaluated. This study demonstrated that a single-dose antibiotic regimen was as effective as a multiple-dose regimen in the prophylaxis of wound infections following abdominal surgery. In addition it demonstrated that the cefotaxime plus metronidazole regimen is comparable to that of cefoxitin and is more cost-effective. It is concluded that a single dose of cefotaxime plus metronidazole provides effective prophylaxis against postoperative wound infections following abdominal surgery.

Inadequate levels of metronidazole in subcutaneous fat after standard prophylaxis

The efficacy of antibiotic prophylaxis depends on appropriate tissue levels of the drug being present at the time of potential wound contamination. Metronidazole concentrations in serum, muscle and subcutaneous fat were measured after a single intravenous dose given at two different intervals before operation. Twenty-six patients undergoing abdominal wall procedures were divided into two groups. Patients in group 1 received metronidazole 500 mg intravenously 2 h before surgery, and those in group 2 were given the drug during induction of anaesthesia. Mean plasma levels of metronidazole at the beginning of the procedure were significantly lower (P = 0.01) in group 1 (7.3 (95 per cent confidence interval 5.7-8.9)) micrograms/ml than in group 2 (12.3 (8.9-15.7)) micrograms/ml although in both cases were above the minimum inhibitory concentration for 90 per cent of Bacteroides fragilis. Similar therapeutic concentrations of metronidazole were achieved in plasma and muscle in both groups at the end of the operation. However, patients in both groups had non-therapeutic concentrations of metronidazole in subcutaneous fat: group 1 0.9 (0.6-1.2) micrograms/mg, group 2 1.2 (0.7-1.7) micrograms/mg at the beginning of operation, and 1.2 (0.8-1.6) and 1.5 (0.9-2.1) micrograms/mg respectively at the end of the procedure. It is concluded that infusion of metronidazole 2 h before surgery or during induction of anaesthesia achieved adequate plasma and muscle levels but failed to achieve therapeutic levels in subcutaneous fat.

Antibiotic prophylaxis in dermatologic surgery

Antibiotic prophylaxis is generally administered either to prevent wound infection or to hinder the development of endocarditis. Although the use of antibiotics in certain circumstances to prevent wound infection can be straightforward, there are other circumstances in which the decision to use antibiotics is much less clear. Endocarditis prophylaxis has traditionally been based on the American Heart Association's guidelines, which do not cover dermatologic surgery. This article discusses the rationale and controversies surrounding the use of antibiotic prophylaxis for prevention of both wound infection and endocarditis, reviews the few studies that pertain to dermatology, and provides recommendations for antibiotic prophylaxis on a case-by-case basis for those who perform dermatologic surgery.

[Antibiotic prophylaxis in hepatobiliary surgery]

Today, hepatic and biliary surgery includes conventional biliary surgery, laparoscopic surgery, interventional radiology, endoscopy and hepatic resection surgery. In conventional biliary surgery, the benefit of antibiotic prophylaxis has been demonstrated. Among the risk factors, some are specific (age > 65 years, gallstones in the common bile duct with or without jaundice, history of acute cholecystitis or of biliary surgery) and the others are non specific such as the CDC new index risk (for scoring from 0 to 3, wound infection rates are respectively 1.36, 2.01, 7.11, 11.54%). The targets for antibiotics used in conventional biliary surgery are E. coli, Klebsiella and Streptococcus. In biliary laparoscopic surgery, the rate of infectious complications and results of antibiotic prophylaxis have not been assessed. However, in laparoscopic surgery, the use of an antibiotic prophylaxis similar to that employed in conventional biliary surgery seems logical. In interventional radiology and endoscopy, the modalities and the benefit of antibiotic prophylaxis have not yet been assessed. Infections (angio-cholecystitis) secondary to these procedures are frequent and severe. They are due to multiresistant hospital microorganisms. Antibiotic prophylaxis regimens for hepatic resections have not yet been assessed and are the same as for conventional biliary surgery.

Prophylactic use of cefuroxime in biliary tract surgery: randomized controlled trial of single versus multiple dose in high-risk patients. Galant Trial Study Group

To assess the efficacy of a single-dose short-acting antibiotic in the prevention of septic complications after biliary surgery, a randomized controlled double-blind multicentre trial was conducted. One dose of cefuroxime before operation (1.5 g intravenously) was compared with a three-dose regimen of the drug as control (1.5 g before and two doses of 0.75 g after operation). The study group comprised 1004 patients with risk factors for infection, who were followed for 4-6 weeks after surgery. The characteristics of both treatment groups were comparable. No significant difference was found between the one- and three-dose antibiotic regimens in preventing postoperative wound infection: 6.6 versus 6.2 per cent for minor wound infection (P = 0.78) and 4.6 versus 3.8 per cent for major wound infection (P = 0.52). The estimated difference in major wound infection rate between the two groups was 0.8 per cent (95 per cent confidence interval -1.7 to 3.3 per cent).

Prophylaxis against sepsis in patients undergoing major surgery

Postoperative infection in general surgical patients is discussed according to operation types. A selection of the huge literature on each group is reviewed, and details from the author's own work and ideas are presented. By discussing these points attempts are made to determine the best regimens for a given set of clinical circumstances. There is a small literature indicating that postoperative chest infection can be prevented by some antibacterial drug regimens, and this question has been addressed; it seems that in the past it has been largely ignored. Some nonantibacterial methods of reducing postoperative infection are also briefly discussed.

Prospective, randomized study comparing amoxycillin-clavulanic acid and cefamandole for the prevention of wound infection in high-risk patients undergoing elective biliary surgery

The efficacy of amoxycillin-clavulanic acid for prevention of postoperative wound infection was compared with that of cefamandole in 150 patients at risk for infected bile while undergoing elective biliary surgery in a prospective, randomized study. The two groups were comparable for age, sex, risk factors, operative procedures and positive bile cultures. Similar numbers of patients had an uncomplicated postoperative course (amoxycillin-clavulanic acid 70%; cefamandole 73%). Four patients in each group developed wound infection. The incidence of postoperative pneumonia, urinary tract infection and number of days (+/- SD) in hospital (amoxycillin-clavulanic acid 10.1 +/- 4.7; cefamandole 9.7 +/- 5.6) were similar. The efficacy of amoxycillin-clavulanic acid and cefamandole in preventing wound sepsis in high-risk patients undergoing biliary surgery was similar. Economic considerations may favour the use of amoxycillin-clavulanic acid.

A randomized trial of one versus three doses of Augmentin as wound prophylaxis in at-risk abdominal surgery

In a randomized prospective trial of prophylactic antibiotics in at-risk abdominal surgery, one dose of intravenous Augmentin (amoxycillin 250 mg and clavulanic acid 125 mg) on induction has been compared with three 8 hourly doses in 900 patients. Wound infection rates which included minor and delayed infections were very similar in those given one dose: 48/449 (10.7%) compared with those given three doses: 49/451 (10.9%) 95% confidence limits - 4.25% + 3.9%. There were more septic and sepsis-related deaths in those patients given one dose (14 deaths) than in those given three doses (7 deaths) P > 0.1 95% CL - 0.4% + 3.0%. However, there were more very elderly patients in the one dose group: 64% of the deaths were aged over 80 and all but one had an emergency operation. There was no difference in the other outcome measures studied which included non-fatal deep sepsis, length of postoperative hospital stay, duration of postoperative fever or the use of antibiotics for postoperative infection. One dose of a suitable intravenous antibiotic gives prophylaxis against wound infection in at-risk abdominal surgery which is at least as effective as multiple doses. However, there may be a risk of overwhelming systemic sepsis in very elderly patients having emergency surgery.

Multifactorial analysis of septic bile and septic complications in biliary surgery

A unifactorial analysis for possible risk factors was applied to 2,700 consecutive operations for benign disease of the biliary tract. A series of high risk factors in relation to positive bacteriology and septic complication could be identified. These risk factors were patients who were elderly (greater than 70 years; p less than 0.001), those who were diabetic, those who had a serum bilirubin greater than 1.1 mg% (p less than 0.001), those who had acute cholecystitis (p less than 0.001), and those in whom choledochal stones were found (p less than 0.001). Using a multivariate analysis, we concluded that in patients with no risk factors (56.9%) the incidence of a positive bacteriology was low (10.9%) and they should receive no antibiotic prophylaxis. Patients with one risk factor (24%), had a 36% incidence of positive bacteriology and minimal pre-operative prophylaxis is recommended. Patients with two or more risk factors (19.1%) had a 77.6% incidence of positive bacteriology and full peri-operative prophylaxis is recommended, starting pre-operatively and continuing for 3 to 5 days postoperatively. The aim of this study was to identify patients at risk for septic complication in biliary surgery and to create new guidelines for the antibiotic treatment of selected groups.

Prophylaxis of postoperative infections

The antibiotic most appropriate for prophylaxis of postoperative infections depends on the nature of the operation. In aseptic (clean) operations, gram-positive postoperative infections are the primary concern, and cefazolin is recommended because of its excellent pharmacokinetics and good activity against gram-positive pathogens, including staphylococci. In those operations where violation of the digestive tract creates a contaminated field, a cefotaxime-generation cephalosporin is the agent of choice because of the excellent safety profiles and the capability of agents of this class to kill essentially all pathogenic gram-negative aerobes as well as a substantial portion of anaerobes. Selection of resistant bacteria has not been significant and is unlikely to become so with single-dose prophylaxis. Occasionally, if there is a high probability that the operative field may be heavily contaminated by anaerobes, metronidazole should be added. Dosing should be sufficient to cover the operative period. Only a single prophylactic dose is necessary, given at the time of induction of anesthesia. For particularly long operations, a second dose of those antibiotics with half-lives shorter than 60 min is required two hours after the first. Single-injection prophylaxis is effective, inexpensive, has no side effects and does not induce bacterial resistance.

A bacteriological assessment of ampicillin with sulbactam as antibiotic prophylaxis in patients undergoing biliary tract operations. The West of Scotland Surgical Infection Study Group

A prospective audit of 644 patients undergoing biliary tract operations has been conducted in ten district general hospitals. All patients received a single dose of ampicillin 2 g and sulbactam 1 g as antibiotic prophylaxis. Bacteria were cultured from the bile of 121 patients. In patients with sterile bile the incidence of postoperative infection was 2.5%, while in those with colonized bile it was 22% (P less than 0.0001). The 35 patients from whose bile bacteria of two or more species were isolated, had a higher incidence of wound infection (34%) than those whose bile yielded only one species of bacterium (17%; P less than 0.05). Seventeen of the 27 patients with colonized bile who developed postoperative infection were shown to be infected by the same organisms that had been isolated from their bile. The patients whose bile yielded organisms resistant to the prophylactic antibiotic combination did not have a significantly higher rate of infection than those from whose bile only sensitive organisms were obtained. A marked difference in sensitivity patterns between the participating hospitals was observed.

Infectious complications after 809 biliary tract operations and results of a prospective randomized single-blind study comparing cefoxitin versus ampicillin plus an inhibitor of beta-lactamases

A retrospective analysis of 809 biliary tract operations revealed postoperative wound infections in 13.4% of 278 patients with bactericholia, compared to 6.9% in patients without bactericholia. More than one third of isolated bacteria were resistant to ampicillin. This was the basis to conduct a prospective randomized single-blind study to compare the efficacy of ampicillin in combination with the beta-lactamase-inhibitor sulbactam with cefoxitin as perioperative prophylaxis in elective biliary surgery. Patients received a single dose of either 2 g ampicillin plus 1 g sulbactam or 2 g cefoxitin as intravenous short-infusion approximately 30 min prior to skin incision. Both groups were comparable concerning demographic and nosographic data. 80 of 83 patients were evaluable for efficacy; 39 received ampicillin/sulbactam and 41 cefoxitin. In the cefoxitin group two wound infections were observed. In the ampicillin/sulbactam group one patient developed postoperative temperatures of greater than 39.0 degrees C, which was regarded as a wound-related infectious complication. In addition, there occurred five urinary tract infections (cefoxitin: 3; ampicillin/sulbactam: 2) but no pulmonary infection. In conclusion, no significant difference between the two groups could be shown. Both regimens were well tolerated with no significant differences between treatment groups. The combination of ampicillin with the beta-lactamase-inhibitor sulbactam can be regarded as safe and as effective compared to cefoxitin for single-dose prophylaxis of post-operative infections after biliary tract operations.

Prophylactic antibiotic use in four Dublin teaching hospitals

A retrospective study of 266 surgical patients revealed that 55% received antibiotics. Of these, 71% had prophylactic and 29% therapeutic courses. Twenty-five per cent of prophylactic courses were started post-operatively, 65% were continued for more than 24 hours, 28% were administered by an inappropriate route and 10% were started more than two hours pre-operatively. Of all courses of antibiotics ordered, 67% had no record of intended duration on the prescription. In 4% of courses the surgeon's orders were not followed. This study demonstrates widespread suboptimal use of antibiotic prophylaxis in a variety of surgical specialties.

Relationship between bile colonization, high-risk factors and postoperative sepsis in patients undergoing biliary tract operations while receiving a prophylactic antibiotic. West of Scotland Surgical Infection Study Group

A prospective audit of 644 patients undergoing biliary tract operations has been conducted to assess the incidence of bile colonization and its association with the incidence of postoperative sepsis when all patients received the same prophylactic antibiotic. The accuracy of the determination of high-risk factors has been assessed as has the correlation between bile colonization and patients assessed as 'high risk'. Organisms were cultured from the bile of 121 (19 per cent) patients and among these the incidence of wound or intra-abdominal sepsis was 22 per cent whereas among patients with sterile bile the incidence was only 2 per cent (P less than 0.0001). Although the incidence of bile colonization within the high-risk group (32 per cent) was more than twice that in the low-risk group (14 per cent), more than half (54 per cent) of the patients with positive bile cultures were in the low-risk group. It is concluded that, despite prophylactic antibiotics, bile colonization remains the major factor associated with postoperative sepsis, but that this cannot be predicted accurately by preoperative assessment of high-risk factors. Furthermore, we believe that a policy of selective administration of prophylactic antibiotics solely to high-risk patients cannot be justified.

Ceftriaxone versus clavulanate-potentiated amoxycillin for prophylaxis against post-operative sepsis in biliary surgery: a prospective randomized study in 200 patients

A prospective study was carried out in 200 consecutive patients undergoing biliary surgery to compare the prophylactic effectiveness of ceftriaxone and clavulanate-potentiated (CP-) amoxycillin. Patients were assigned in a randomized fashion to two groups and received ceftriaxone (2 g intravenously pre-operatively), or CP-amoxycillin (1200 mg, to be repeated for 2 more doses in the case of patients undergoing procedures other than elective cholecystectomy). Post-operative wound infection occurred in 4% of patients in each group. Administration of ceftriaxone was associated with a lower incidence of post-operative pyrexia and chest infection as well as with a shorter hospital stay.

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.

A prospective randomized trial to compare triple dose mezlocillin with triple dose cefuroxime plus metronidazole as prophylaxis in colorectal surgery

The results of a prospective randomized clinical trial to compare three dose regimens of mezlocillin with cefuroxime plus metronidazole for prophylaxis in emergency and elective colorectal surgery are reported. Severe wound infection occurred in five patients (10%) receiving mezlocillin and in four patients (7%) receiving cefuroxime and metronidazole. There were two episodes of septicaemia, each in the mezlocillin group. The total number of surgically related infections was less with cefuroxime plus metronidazole (n = 10) compared with mezlocillin (n = 17), but this was not statistically significant (P greater than 0.1).

Ceftriaxone versus povidone iodine in preventing wound infections following biliary surgery

The effect of either prophylactic antibiotic or wound antiseptic on bile bacteriology, wound and other postoperative sepsis has been studied in a controlled prospective randomised trial of 243 patients undergoing biliary surgery at a district general hospital. Wound infection rates were significantly less in patients given intravenous ceftriaxone (1%) at induction of anaesthesia when compared to povidone iodine sprayed into the wound at the completion of surgery (9%) (P = 0.02). In all but one patient infected wounds grew organisms identical to those cultured from the bile. There were also fewer chest and urinary infections in the ceftriaxone group but this was not statistically significant.

Multicenter open trial of cefotetan and cefoxitin in elective biliary surgery

The present study was performed in two phases. In phase I, 112 patients were randomized to either 2 g cefotetan as a single prophylactic dose or 2 g cefoxitin every 6 hours for a maximum of 4 doses; phase II included 148 patients who were randomized to either 1 g cefotetan as a single dose or cefoxitin dosed as in phase I. The randomization was 2:1 cefotetan to cefoxitin in both phases. Nonevaluability rates were 10 percent for the cefotetan patients and 22 percent for the cefoxitin patients, the majority being due to dosing errors. Demographic characteristics demonstrated 88 percent to be female, 81 percent to be less than 65 years of age, and the average weight to be 165 lb. There were no differences in these characteristics among the groups. Common duct exploration was performed in 6 percent of the 2 g cefotetan patients, 9 percent in the 1 g cefotetan patients, and 13 percent in the 2 g cefoxitin patients. There were five clinical failures of prophylaxis: one wound infection in the 2 g cefotetan patients, one wound infection and one drain tract infection in the 1 g cefotetan patients, and one wound infection and one case of cholangitis in the 2 g cefoxitin patients. The clinical success rates were 98 percent in the 2 g cefotetan patients, 98 percent in the 1 g cefotetan patients, and 97 percent in the 2 g cefoxitin patients.

Single-dose clavulanate-potentiated amoxycillin versus three-dose cefotaxime in the prevention of wound infection following elective cholecystectomy: a prospective randomized study

A prospective randomized study was carried out to evaluate the efficacy of clavulanate-potentiated amoxycillin with that of cefotaxime as prophylactic agents for the prevention of sepsis following elective cholecystectomy. One hundred patients were randomized into two treatment groups. In the first group, each patient received a single intravenous dose (1200 mg) of clavulanate-potentiated amoxycillin 2 h before surgery. In the second group, patients were given intravenous cefotaxime, in three doses (2 g each) during surgery, and 6 and 12 h after their operation. No case of serious post-operative sepsis occurred in either group. Superficial wound infection occurred in 2% of patients receiving a single pre-operative dose of clavulanate-potentiated amoxycillin and in 6% of those given cefotaxime according to the three-dose regimen.

Topical antibiotics in the high-risk biliary surgical patient. A prospective, randomized study

This randomized, prospective study has evaluated the efficacy of topical antibiotics in preventing infective complications in patients undergoing high-risk biliary surgery. Sixty-nine patients who underwent bile duct exploration, choledochoenteric anastomosis, or cholecystectomy, either for acute cholecystitis or because they were older than 65 years of age, were randomized to the following three groups: Group I, topical antibiotics alone (22 patients); Group II, cefoxitin and topical antibiotics (24 patients); and Group III, penicillin, tobramycin, clindamycin, and topical antibiotics (23 patients). The incidence of infective complications was no different among the groups. There was one wound infection in each group, one episode of bacteremia in Group II, and no intraabdominal abscesses. This study has demonstrated that parenteral antibiotics administered prophylactically in the perioperative period offer no additional benefit over the use of effective topical antibiotics used intraoperatively in patients undergoing high-risk biliary surgery.

Single dose mezlocillin versus three dose cefuroxime plus metronidazole for the prophylaxis of wound infection after large bowel surgery

A prospective, randomized, controlled trial was conducted in 116 consecutive patients undergoing colorectal surgery to compare single dose prophylaxis with mezlocillin to cefuroxime plus metronidazole in three doses. Patients were randomized to receive either a single dose of iv mezlocillin (5.0 g) or three doses of iv cefuroxime plus metronidazole at 8-hourly intervals. The first dose was given on the operating table. The overall wound infection rate in the mezlocillin treated patients (n = 54) was 30% and in the patients treated with cefuroxime plus metronidazole (n = 56) 25%. This difference is not statistically significant. When trivial wound infections were disregarded the wound infection rates were 11% and 16% respectively, which again was not statistically significant.

Surgery in the patient with liver disease

This article deals with the effects of anesthesia and surgery on the healthy and diseased liver and the preoperative assessment of patients with liver disease. Emphasis is placed on estimating surgical risk. Guidelines for optimal preoperative preparation are discussed.

Prospective randomised study of preoperative endoscopic sphincterotomy versus surgery alone for common bile duct stones

One hundred and twenty patients with known common bile duct stones were entered into a prospective randomised study of preoperative endoscopic sphincterotomy and stone clearance (group 1) versus surgery alone (group 2). Five patients were incorrectly entered; the 55 patients randomised to group 1 and the 60 randomised to group 2 were well matched with respect to clinical features and biochemical and medical risk factors. In group 1 endoscopic stone clearance was successful in 50 patients (91%); five of these patients refused elective surgery, though this was subsequently necessary in one. In group 2 common bile duct stones were cleared surgically in 54 of 59 patients (91.5%); one patient was treated by endoscopic sphincterotomy alone because of a myocardial infarct. The overall major complication rate in group 1 was 16.4% and included two deaths; in group 2 this was 8.5% and included one death. The minor complication rate in group 1 was 16.4% and that in group 2 13.6%. These differences in outcome were not significant. Despite a significant reduction in total hospital stay of patients in group 1, these results do not support the routine use of preoperative endoscopic sphincterotomy in patients having biliary surgery for stones in the common bile duct.

Prophylactic antibiotics for patients undergoing elective biliary tract surgery: a prospective randomized study of cefotiam and cefoperazone

Cefotiam, a second generation cephalosporin and cefoperazone, a third generation cephalosporin have a broad spectrum of activity against a majority of organisms commonly found in the bile. Although cefoperazone is excreted into the human bile to a greater extent than is cefotiam, there are no comparative data available that cefoperazone prophylaxis is safer and more effective than cefotiam for patients undergoing biliary tract surgery. A prospective randomized study was performed to compare the safety and efficacy of cefotiam with those of cefoperazone for prophylaxis in patients undergoing elective biliary tract surgery. The incidence of postoperative infection was not significantly different between the cefotiam group (n = 86) and the cefoperazone group (n = 86). The rate of side effects, however, was significantly different. In the cefotiam group, only one patient had diarrhea whereas in the cefoperazone group, eight had diarrhea and one skin eruption. Clostridium difficile cytotoxin was nil in those with diarrhea. Diarrhea in all patients was mild and recovery was rapid. Cefotiam is thus safer and as effective as cefoperazone in preventing postoperative infections following biliary tract surgery. We suggest that cefotiam is the first choice antibiotic for prophylaxis in biliary tract surgery.

Cephalosporins in surgery. Prophylaxis and therapy

Prophylactic antibiotics in surgery are intended to prevent morbidity and mortality, as well as to reduce the duration and cost of hospitalisation. The indications for prophylaxis, and its effectiveness, should be evaluated with these criteria in mind. The basis for antibiotic prophylaxis in surgery is either provision of an effective concentration of antibiotic in the tissue site at the time of potential contamination, or (primarily in the case of colorectal surgery) to reduce the inoculum of potentially contaminating bacteria. Cephalosporins are the antibiotics most widely used for prophylaxis in surgery, and have clearly been shown to reduce postoperative morbidity in vaginal hysterectomy, resection of head and neck cancers, vascular grafting, total joint replacement, repair of hip fractures, and high risk gastroduodenal surgery. They are probably also useful in cardiac surgery, abdominal hysterectomy, caesarean section, and colorectal surgery. For orthopaedic, cardiac, gynaecological, and gastroduodenal procedures it is important to select an antibiotic with proven clinical activity against Gram-positive organisms. For head and neck surgery, the spectrum of activity should also include oral anaerobes and Enterobacteriaceae. For biliary surgery an antibiotic effective against both Gram-positive and Gram-negative organisms may offer at least theoretical advantages, while for appendicectomy a cephamycin represents the most appropriate choice. In colorectal procedures, activity against B. fragilis is the major consideration in selecting an antibiotic for systemic prophylaxis. When intra-abdominal sepsis occurs following surgery, a potentially wide range of bacteria may be implicated, but in practice such infections are due to a small number of species, with B. fragilis most commonly implicated. The most useful cephalosporins in this setting are those active against both aerobic Gram-negative bacteria and anaerobes, especially B. fragilis. In practice, an aminoglycoside is often administered concomitantly. Importantly, prompt surgical treatment is the cornerstone of management of abdominal sepsis, and empirical antibiotic therapy should be adjusted as needed when culture and sensitivity tests become available.

Postcholecystectomy wound infection. The impact of prophylactic antibiotics on the epidemiology of infections

The clinical courses of 347 patients undergoing gallbladder surgeries were monitored to study the epidemiology of postcholecystectomy wound infection in a hospital in which high-risk patients received prophylactic antibiotics. Overall, 3.8% of patients had wound infections. Patients who had positive bile cultures taken during surgery or positive intraoperative wound cultures had higher rates of infection than patients with negative cultures. However, there was a poor correlation among the bacterial isolates that were recovered from the bile or the wound surface during surgery and from postoperative infections. Antibiotic-sensitive enteric bacteria were recovered from bile samples at surgery, gram-positive organisms and enteric gram-negative bacteria were isolated from intraoperative cultures of the wound surface, and antibiotic-resistant gram-negative bacteria or enterococci were recovered from wounds that developed postoperative infections. There was a strong association between the prior receipt of prophylactic antibiotics and infections with antibiotic-resistant bacteria. Data suggest that bactibilia is still an important epidemiologic marker that identifies patients at high risk for subsequent wound infection. However, in patients who have received prophylactic antibiotics, intraoperative cultures cannot be relied on to guide the choice of empiric therapeutic antibiotics for postoperative infections. Bacteria responsible for these infections are not identified by cultures taken at the time of surgery and are often resistant to the class of antibiotics used for prophylaxis.

Single dose prophylaxis in elective cholecystectomy. A prospective, double-blind randomized study

We tested the effectiveness of a single dose of prophylactic antibiotic (gentamicin) in elective cholecystectomy in a double-blind, controlled randomized study. All patients recognized preoperatively as being at risk were excluded. The treatment group comprised of 102 patients received a single dose of gentamicin and the 74 patients in the control group received a placebo. Of the patients who received gentamicin, wound infection developed in 4.9 percent versus 13.5 percent in the control group. Among 45 patients who had positive bile cultures, the wound infection rate for those in the treatment group was 14 percent versus 44 percent for those in the control group. Of 17 patients who underwent unexpected exploration of the choledochus, none of those in the treatment group had development of wound infection. The rate of wound infection in the control group was 50 percent. As 30 percent of the patients undergoing elective cholecystectomy were found to have risk factors for the development of wound infection which could not be identified preoperatively, we recommend single dose prophylaxis for all patients undergoing cholecystectomy.

Single dose systemic antibiotic prophylaxis of surgical wound infections

The proper duration of antimicrobial use for the prevention of postoperative surgical infection has been a subject of controversy. Currently, more than 40 published clinical trials are available in which the efficacy of single dose surgical prophylaxis with parenteral antimicrobials has been studied. These studies have compared single doses versus multiple doses of the same agent, single doses of antimicrobial versus placebo, single doses of various antimicrobials, and a single dose of one agent versus multiple doses of another agent. In all trials in which single dose regimens were compared with multidose regimens, the single dose regimens resulted in a similar frequency of postoperative wound infections. Single antimicrobial doses, usually cephalosporins given immediately before operation, are effective in preventing wound infections in gastric, biliary, and transurethral operations, hysterectomies and cesarean sections. For colorectal operations, the value of single parenteral doses of various agents has been established; however, it is not clear if there is an added benefit when oral antimicrobials are also used. For open heart operations or those in which prosthetic materials are implanted, the value of single dose regimens has not been established.