Comparison of one dose versus three doses of prophylactic antibiotics, and the influence of blood transfusion, on infectious complications in acute and elective colorectal surgery

In a randomized prospective controlled trial involving 311 patients undergoing acute or elective colorectal surgery, the efficacy and safety of two different single dose and one triple dose regimen of antibiotic prophylaxis, as well as the influence of blood transfusion on postoperative infectious complications, were studied. Postoperative infectious complications occurred in a total of 59 patients (19.0 per cent). There were no major differences between the three treatment groups. Thirty-four patients (10.9 per cent) developed abdominal wound infection, 17 patients (5.5 per cent) intra-abdominal abscess and 16 patients (5.1 per cent) anastomotic leakage. Of 202 patients (65.0 per cent) requiring blood transfusion during hospitalization 57 (28.2 per cent; 95 per cent confidence limits of 23-36 per cent) developed infectious complications, whereas two non-transfused patients (1.8 per cent; 95 per cent confidence limits of 0.2 to 6 per cent; P less than 0.001) developed infectious complications. It is concluded that one single dose of antibiotic prophylaxis in acute and elective colorectal surgery is as protective as a triple dose regimen. The development of infectious complications despite antibiotic prophylaxis is strongly related to blood transfusion.     

Ten-year computerized audit of infection after abdominal surgery

A prospective audit of the frequency of infective complications after all abdominal operations was carried out between January 1977 and December 1986. A total of 3100 abdominal procedures (2041 elective; 1059 emergency) were performed in 3056 patients. There were 50 (1.6 per cent) in-hospital and 66 (2.1 per cent) late wound infections (overall 3.7 per cent). Fifty-four (1.8 per cent) patients developed postoperative intraperitoneal sepsis. Ninety-eight patients died (overall mortality 3.2 per cent) and intraperitoneal sepsis was a related factor in twelve (0.4 per cent). Wound infection, peritoneal sepsis and mortality were related to the degree of operative contamination and to reoperation. The results support the traditional, although sometimes inadequately stressed, teaching that technique is an important factor in preventing infection. Infection is also reduced by peroperative antibiotic lavage. The limited value and the potential difficulties of the unstructured introduction of computerized audit should be recognized.     

Treatment of intra-abdominal sepsis

Twenty-three surgeons at three McGill University hospitals were interviewed about their treatment of intra-abdominal sepsis. They described their use of antibiotics, operative practices and other treatment of generalized peritonitis and intra-abdominal abscesses. If more than 75% of respondents used a given method, its use was considered "uniform" unless substantial interhospital variation existed for that method. Treatment was variable in 18 situations. Only four of these involved systemic antibiotic use--drug regimens in appendicitis and intra-abdominal abscess, and duration of antibiotic therapy following appendicitis and perforated duodenal ulcer. The other 14 examples of variation were in operative management. In generalized peritonitis, they were: use of diagnostic paracentesis; abdominal lavage with saline alone versus saline plus antibiotic use; whether the peritoneum should ever be left open; the use or avoidance of drains; primary versus delayed wound closure in appendicitis, bowel perforation and trauma with gastrointestinal perforation and, finally, wound lavage with saline alone or with antibiotics. Treatment of intra-abdominal abscesses varied in regard to the diagnostic and therapeutic roles of percutaneous needle aspiration, the preferred route of drainage of a pelvic abscess, the use of an extra- or trans-serosal approach to a subphrenic abscess, local versus full abdominal exploration for a single abscess and the type of drain used. The authors conclude that operative management of intra-abdominal sepsis varies widely among surgeons. This fact invalidates many "controlled" trials of antibiotics and should focus attention less on drugs and more on surgical treatment.     

Combined topical povidone-iodine and systemic antibiotics in postappendicectomy wound sepsis

Three hundred and fifteen patients with appendicitis were randomized into two groups. One group received pre-operative systemic gentamicin and metronidazole while the other group received 1 per cent topical povidone-iodine solution in addition to the antibiotics. For early appendicitis including normal and acutely inflamed appendices, only one dose of antibiotics was used. The postoperative wound sepsis was very low in both groups of patients and there was no statistical difference between them. For late appendicitis including gangrenous and perforated appendices, the antibiotics were continued for 7 days. Eight out of 51 patients who had the topical agent developed wound sepsis compared with one out of 52 patients who received no topical agent. This difference is statistically significant (P = 0.03). All wound infections presented within 2 weeks of operation and were deep. Povidone-iodine, 1 per cent, adversely affects the wound infection rate in late appendicitis and should not be used.     

Postoperative chest wound infections in patients requiring coronary bypass. A controlled study evaluating prophylactic antibiotics.

A controlled study investigating clean chest wound infections in 904 patients undergoing myocardial revascularization was performed. Four hundred fifty-one patients received systemic antibiotics before and after the operation, and 453 patients received no prophylactic systemic antibiotics. The infection rate was 1.10 per cent and 1.76 per cent, respectively, indicating no statistical difference between the two groups. Preoperative skin preparation and subsequent local antibiotic wound irrigation may be the most important factors in preventing clean wound infection.     

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.     

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

Background

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

Methods

We reviewed the charts of patients with ruptured appendicitis who underwent open appendectomy performed by the same pediatric surgeon at the Hospital for Sick Children, Toronto, Canada between 1969 and 2003, inclusive. We evaluated 3 types of prophylaxis: subcutaneous (SC) antibiotic powder, peritoneal wound drain and intravenous (IV) antibiotics. We divided the sample into 4 treatment groups: peritoneal wound drain alone (group 1); peritoneal wound drain, SC antibiotic powder and IV antibiotics (group 2); SC antibiotic powder and IV antibiotics (group 3); and IV antibiotics alone (group 4). We used the χ² test with Bonferroni correction for multiple comparisons.

Results

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

Conclusion

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

Postoperative enterococcal infection after treatment of complicated intra-abdominal sepsis

BACKGROUND: The prevalence of enterococcal isolation and factors associated with postoperative enterococcal infection remain ill defined. METHODS: A prospective longitudinal observational study was conducted of consecutive patients with a first episode of intra-abdominal infection and a positive microbiological culture who did or did not develop a postoperative septic complication involving enterococci. The prevalence of initial enterococcal isolation was determined for each focus of infection. Postoperative enterococcal infections were related to whether appropriate (piperacillin--tazobactam), suboptimal (carbapenems) or inappropriate (cefotaxime plus metronidazole) antienterococcal therapy had been administered empirically. RESULTS: Enterococci were isolated in 42 (21 per cent) of the 200 patients investigated. The isolation rates were 11 per cent for community-acquired peritonitis, 50 per cent for postoperative peritonitis and 23 per cent for intra-abdominal abscesses of both origins. No enterococci were isolated from 49 patients with perforated appendicitis. Independent factors for postoperative enterococcal infection were type of intra-abdominal infection (P = 0.006), Acute Physiology And Chronic Health Evaluation (APACHE) II score greater than 12 (P = 0.04) and inappropriate empirical antibiotic cover (P = 0.05). Postoperative enterococcal infections were associated with a high mortality rate (21 versus 4 per cent; P < 0.0007). CONCLUSION: Enterococci are frequently isolated from intra-abdominal infections of non-appendiceal origin and are often involved in postoperative infectious complications, particularly peritonitis. Empirical antibiotic therapy covering Enterococcus faecalis should be contemplated in some circumstances.     

Colectomy, mucosal proctectomy, and ileal pouch-anal anastomosis. A prospective trial of optimal antibiotic management.

The ideal prophylactic antibiotic regimen has not been established for patients undergoing colectomy, mucosal proctectomy, and endorectal ileoanal anastomosis, a prolonged operation frequently accompanied by abdominal and pelvic contamination and associated with an infection rate up to 20%. The aim of this study was to evaluate, in a prospective, randomized, double-blind fashion, the efficacy of a short perioperative course compared to an extended postoperative course of intravenous antibiotics (cefoxitin) in patients undergoing colectomy with ileoanal anastomosis. Forty patients with ulcerative colitis or familial polyposis coli received a mechanical and oral antibiotic bowel preparation and a standard three-dose perioperative course of intravenous cefoxitin. Patients then were randomized to receive intravenous cefoxitin, 1 g every 6 hours, or placebo for 5 days. No differences in overall postoperative morbidity were observed and neither group developed intra-abdominal, pelvic, or wound infections. It is concluded that a standard three-dose perioperative course of intravenous antibiotics provides adequate prophylaxis in the prevention of infectious complications in patients undergoing colectomy, mucosal proctectomy, and ileoanal anastomosis.     

Oral versus systemic antibiotic prophylaxis in elective colon surgery: a randomized study and meta-analysis send a message from the 1990s.

OBJECTIVES: To compare the efficacy of combined oral and systemic antibiotics (combined) versus systemic antibiotics (systemic) alone in preventing surgical site infection in elective surgery of the colon, and to perform a meta-analysis of randomized studies comparing combined versus systemic antibiotics in elective colon surgery. DESIGN: A double-blind, placebo-controlled, randomized clinical trial. SETTING: The Queen Elizabeth Hospital, Montreal, a university-affiliated community hospital. PARTICIPANTS: Two hundred and fifteen patients scheduled to undergo elective surgery of the colon. INTERVENTIONS: Patients were randomized to receive neomycin and metronidazole orally (109 patients) or identical placebos (106 patients) on the final preoperative day. All were given amikacin and metronidazole intravenously just before operation. Thirteen randomized series comparing combined and systemic antibiotic prophylaxis in elective colon surgery were identified for meta-analysis. OUTCOME MEASURES: Rates of postoperative surgical site infections: risk differences, risk ratios (RRs) and 95% confidence intervals (CIs); organisms found in the colon and wound fat at surgery, and in infected wounds. RESULTS: Three patients in the systemic group, and 5 in the combined group were excluded. Wound infections occurred in 5 patients in the combined group but in 17 in the systemic group (p < 0.01, RR = 0.29, 95% CI 0.11-0.75). Bacteria isolated from wound infections and wound fat were similar to those found in the colon. They were more frequent in the colon in the systemic group (p < 0.001) and occurred in wound fat in the systemic group twice as often as in the combined group (p < 0.001). By stepwise logistic regression, the presence of bacteria in wound fat at surgery was the strongest predictor of postoperative wound infection (p < 0.002). In the meta-analysis, the summary weighted risk difference in surgical site infections between groups (d(w)) and the summary RR both favoured combined prophylaxis (d(w) = 0.56, 95% CI 0.26-0.86; RR = 0.51, 95% CI 0.24-0.78; p < 0.001). CONCLUSIONS: In elective surgery of the colon combined oral and systemic antibiotics are superior to systemic antibiotics in preventing surgical site infections. Orally administered antibiotics add value by reducing bacterial loading of the colon and wound fat contamination, both associated with postoperative wound infection. Meta-analysis of randomized clinical trials reported from 1975 to 1995 supports these conclusions.     

Septic complications after appendicectomy for perforated appendicitis. A controlled clinical trial metronidazole and topical ampicillin

A prospective, controlled trial of antibiotic therapy was carried out in 90 patients with perforated appendicitis. One randomly selected group received systemic metronidazole, started peroperatively, plus locally instilled ampicillin. The other group, also randomly selected, received only local ampicillin. There was no statistically significant difference in the overall frequency of postoperative septic complications (wound infection or intra-abdominal abscess) between the two groups, but wound infections were significantly fewer in the patients given metronidazole. There was no intergroup difference in hospitalization time. Treatment with systemic metronidazole and local ampicillin is recommended in patients operated on for perforated appendicitis.     

Morbidity of colostomy closure

An unexpectedly high morbidity (28 per cent) followed colostomy closure in 100 patients. One patient died postoperatively because of sepsis resulting from disruption of the colon anastomosis. Wound infection (10 per cent), intraperitoneal abscess (1 per cent), bowel obstruction (7 per cent), and fecal fistula (4 per cent) were other significant complications. Wound sepsis was greater after primary than after delayed wound closure. Obstruction did not correlate with the use of either an open or closed technic of anastomosis. Three patients required reoperation for complications.Temporary colostomy was constructed for colon injury in 85 per cent of patients. In view of the considerable morbidity of colostomy closure, alternate technics of managing colon trauma should be considered. Such technics include primary closure and exteriorization of repaired colon. When temporary colostomy is unavoidable, closure is best done by open, two layer anastomosis with delayed wound closure. Colostomy should be recognized as an important procedure associated with significant morbidity.     

Immediate resection in emergency large bowel surgery: a 7 year audit

In a consecutive series of 153 emergency admissions with large bowel disease during a 7 year period, 49 per cent were for colonic obstruction, 46 per cent for peritonitis and 5 per cent for miscellaneous conditions. Urgent operation was performed on 104 (68 per cent) patients. Of those operated upon, 82 (79 per cent) had a primary resection with a mortality rate of 12.2 per cent, intraperitoneal sepsis rate of 2.4 per cent and wound sepsis rate of 7.3 per cent. The median postoperative hospital stay was 21 days. An immediate anastomosis was performed in 46 (56 per cent) patients with a mortality rate of 8.7 per cent, anastomotic leak rate of 2.2 per cent, and wound sepsis rate of 8.7 per cent. The median postoperative hospital stay was 19 days. The mortality in patients presenting with large bowel emergencies is related to age and advanced malignant disease. Immediate resection is applicable in over 80 per cent of patients requiring urgent operation and morbidity can be low and treatment economical. Immediate anastomosis after proximal colonic resection is safe and the use of intra-operative colonic irrigation permits a primary anastomosis in selected patients after emergency resection of the distal colon.     

Preoperative biliary drainage: Impact on intraoperative bile cultures and infectious morbidity and mortality after pancreaticoduodenectomy

Whether it is necessary to perform biliary drainage for obstructive jaundice before performing pancreaticoduodenectomy remains controversial. Our aim was to determine the impact of preoperative biliary drainage on intraoperative bile cultures and postoperative infectious morbidity and mortality following pancreaticoduodenectomy. We retrospectively analyzed 161 consecutive patients undergoing pancreaticoduodenectomy in whom intraoperative bile cultures were performed. Microorganisms were isolated from 58% of these intraoperative bile cultures, with 70% of them being polymicrobial. Postoperative morbidity was 47% and mortality was 5%. Postoperative infectious complications occurred in 29%, most commonly wound infection (14%) and intra-abdominal abscess (12%). Eighty-nine percent of patients with intra-abdominal abscess (P = 0.003) and 87% with wound infection (P = 0.003) had positive intraoperative bile cultures. Microorganisms in the bile were predictive of microorganisms in intraabdominal abscess (100%) and wound infection (69%). Multivariatc analysis of preoperative and intraoperative variables demonstrated that preoperative biliary drainage was associated with positive intraoperative bile cultures (P <0.001), postoperative infectious complications (P = 0.022), intra-abdominal abscess (P = 0.061), wound infection (P = 0.045), and death (P = 0.021). Preoperative biliary drainage increases the risk of positive intraoperative bile cultures, postoperative infectious morbidity, and death. Positive intraoperative bile cultures are associated with postoperative infectious complications and have similar microorganism profiles. These data suggest that preoperative biliary drainage should be avoided in candidates for pancreaticoduodenectomy. Presented at the 1998 Annual Meeting of the American Gastroenterological Association, New Orleans, La., May 19, 1998.     

Implications of leukocytosis and fever at conclusion of antibiotic therapy for intra-abdominal sepsis.

Outcomes of 65 patients after operation who had exhibited a clinical response to treatment for intra-abdominal sepsis were compared based on the presence or absence of leukocytosis and fever at the conclusion of antibiotic therapy. Fifty-one patients were afebrile when antibiotics were stopped. Intra-abdominal infection developed in 7 of 21 (33%) who had a persistent leukocytosis, but no intra-abdominal infections developed after operation in 30 patients who had normal WBC counts at the end of antibiotic treatment (p less than 0.005). Nosocomial infections developed in 6 (12%) of the 51 patients, and there was no difference in the incidence between patients with or without leukocytosis. Eleven of 14 (79%) patients who were still febrile when antibiotics were discontinued developed infections after operation. Nosocomial infections occurred in three (21%) and intra-abdominal infections in eight (57%). Of the 15 patients who developed intra-abdominal infection after operation, only four responded to appropriate antibiotic treatment without requiring further surgery. The other patients required surgical management for definitive control within two months of the initial operation. In conclusion, patients at risk of developing infection after operation after exhibiting a clinical response to treatment of intra-abdominal sepsis are those who are afebrile with a persistent leukocytosis or who are still febrile when antibiotics are stopped.     

Wound sepsis following gastrointestinal surgery: a comparison of topical and two-dose systemic cephradine.

A prospective study of the effect of the route of administration of prophylactic antibiotic on the wound infection rate following gastrointestinal surgery was performed. Patients were randomly allocated to one of three groups: group 1 received no form of antibiotic prophylaxis; group 2 received 1 g of cephradine applied topically to the wound at closure; group 3 received 1 g of cephradine intravenously at induction of anaesthesia and a further intravenous dose of 500 mg 4 h later. Wound infections occurred in 12 of 83 patients in the control group (14.5 per cent), in 6 of the 83 patients in the group who received topical antibiotic (7.2 per cent) and in 3 of the 82 patients who received systemic antibiotics (3.6 per cent). Only the group who received systemic antibiotic showed a statistically significant reduction in the incidence of wound infections compared with the control group (P = 0.03).     

Gunshot wounds of the colon: A review of 100 consecutive patients,with emphasis on complications and their causes

The cases of one hundred civilian patients with gunshot wounds of the colon treated at the Louisville General Hospital have been reviewed. Most injuries were in the transverse colon (44 per cent), followed by the ascending colon (27 per cent), rectosigmoid (19 per cent), and descending colon (10 per cent). Associated injuries occurred in 81 per cent of the patients; the small bowel was the most common structure injured.Primary closure was used in 52 per cent of the patients, with a resultant 19 per cent rate of wound infection and 14 per cent rate of serious complication. When the extent of contamination or tissue destruction required resection, an attempted primary anastomosis was followed by a high rate of wound infection (57 per cent) and serious complications (36 per cent) as compared with end-colostomy and mucous fistula, which resulted in a 24 per cent rate of wound infection and 24 per cent rate of serious complication. The rate of wound infection between these groups is significant (p = 0.05). Results with end-colostomy and mucous fistula were better than with attempted primary anastomosis.Primary closure of missile injuries of the colon is feasible but should not be attempted in the presence of gross fecal peritonitis or massive tissue destruction. If resection is undertaken, end-colostomy (or ileostomy) and distal mucous fistula should be performed in the presence of intra-abdominal contamination to reduce the incidence of postoperative wound infection and serious complications. Delayed primary closure should also reduce the rate of wound infection in these patients.     

Incidence and significance of intraperitoneal anaerobic bacteria.

To amplify recent interest in anaerobic infections following abdominal disease, trauma, or surgery, 512 consecutive patients subjected to emergency celiotomy had both aerobic and anaerobic cultures taken of peritoneal fluid as well as all complicating wound and intra-abdominal infections. Average time between peritoneal entry of abscess drainage and specimen incubating under anaerobic conditions was less than two minutes. During 4 of the seven study months, patients had antibiotic therapy randomized, with clindaymcin or cephalothin being sole parenteral agents and given intravenously prior to operation and for 5 days thereafter. Results demonstrated that anaerobes uniformly contaminate the peritoneal cavity whenever distal or obstructed intestine has been perforated, irrespective of the cause. Although all but one of the 123 complicating wound and intra-abdominal infections were due solely or at least in part to aerobic pathogens, 2/3 of such infections also contained one or more different anaerobic species acting in synergism with the aerobes. No significant difference in incidence of postoperative infection or in infecting bacteria could be found with respect to antibiotic administered or etiology of perforation. Indeed, duration of bacterial exposure to atmospheric oxygen was the most critical factor influencing culture recoverability of anaerobic organisms, likelihood of ensuing wound or peritoneal sepsis participated in by an anaerobe, and success in control of established infections harboring anaerobes.     

Experimental evaluation of primary repair of colonic injuries.

To evaluate the management of colonic injuries, experimental models simulating acute injuries of the colon were studied utilizing New Zealand white rabbits. Seventy-nine rabbits underwent primary repair of colonic injuries in the presence of massive contamination and none showed any evidence of anastomotic leakage or breakdown. The fact that primary colonic repairs do heal even in the presence of infection suggests that breakdown of colonic anastomosis results from factors other than infection. Despite the absence of anastomotic leaks in this series, morbidity and mortality were high in those animals not given antibiotics. The high morbidity and mortality were due to peritonitis, intra-abdominal abscess, and wound infection, and were directly proportional to the length of time from colonic injury to repair. On the basis of this study, it is concluded that most isolated injuries of the colon can be closed primarily, if antibiotic therapy is begun immediately after injury and continued throughout the operative and postoperative periods.     

Combined topical and systemic antibiotic prophylaxis in experimental wound infection

The effectiveness of a combined topical and systemic antibiotic regimen was studied in an animal model previously shown to simulate clinical surgical wound infection. At a high level of bacterial contamination, the combination regimen produced a lower infection rate than either a placebo (p < 0.01), a topical antibiotic administered alone (p < 0.01), or a systemic antibiotic administered alone. At a lower level of bacterial contamination, no additional reduction in infection rates was produced by the combination regimen when compared with systemic antibiotic administered alone. These experimental results suggest that when wound contamination is great, a combination of topical and systemic antibiotics is the more effective regimen. Where wound contamination is less severe, systemic antibiotic prophylaxis is all that is required; no further benefit is obtained by the additional administration of topical antibiotics. Clinical trials appear justified to confirm or refute this hypothesis.