Bacterial Decontamination: Bowel Preparation and Chlorhexidine Bathing

Infectious complications following bowel surgery continues to be a leading cause of postoperative morbidity. Both patient- and procedure-related factors contribute to risk. Compliance with evidence-based process measures is the best strategy for prevention of surgical site infections. Three process measures that aim to reduce the bacterial load present at the time of surgery are mechanical bowel preparation, oral antibiotics, and chlorhexidine bathing. There is heightened awareness of surgical site infections, in part due to improved access to reliable postoperative complication data for colon surgery as well as incorporation of surgical site infection into public reporting and pay-for-performance payment models. As a result, the literature has improved with regard to the effectiveness of these methods in reducing infectious complications. Herein, we provide the evidence to support adoption of these practices into colorectal surgery infection prevention programs.

Perioperative synbiotics administration decreases postoperative infections in patients with colorectal cancer: a randomized, double-blind clinical trial

OBJECTIVE

to evaluate the effect of perioperative administration of symbiotics on the incidence of surgical wound infection in patients undergoing surgery for colorectal cancer.

METHODS

We conducted a randomized clinical trial with colorectal cancer patients undergoing elective surgery, randomly assigned to receive symbiotics or placebo for five days prior to the surgical procedure and for 14 days after surgery. We studied 91 patients, 49 in the symbiotics group (Lactobacillus acidophilus 108 to 109 CFU, Lactobacillus rhamnosus 108 to 109 CFU, Lactobacillus casei 108 to 109 CFU, Bifi dobacterium 108 to 109 CFU and fructo-oligosaccharide (FOS) 6g) and 42 in the placebo group.

RESULTS

surgical site infection occurred in one (2%) patient in the symbiotics group and in nine (21.4%) patients in the control group (p=0.002). There were three cases of intraabdominal abscess and four cases of pneumonia in the control group, whereas we observed no infections in patients receiving symbiotics (p=0.001).

CONCLUSION

the perioperative administration of symbiotics significantly reduced postoperative infection rates in patients with colorectal cancer. Additional studies are needed to confirm the role of symbiotics in the surgical treatment of colorectal cancer.

The Obese Colorectal Surgery Patient: Surgical Site Infection and Outcomes

BACKGROUND

Obese patients undergoing colorectal surgery are at increased risk for adverse outcomes. It remains unclear whether these risks can be further defined with more discriminatory stratifications of obesity.

OBJECTIVE

The purpose of this study was to understand the association between BMI and 30-day postoperative outcomes, including surgical site infection, among patients undergoing colorectal surgery.

DESIGN

This was a retrospective cohort study.

SETTINGS

The 2011-2013 American College of Surgeons National Surgical Quality Improvement Program database was used.

PATIENTS

Patients included those undergoing elective colorectal surgery in 2011-2013 who were assessed by the American College of Surgeons National Surgical Quality Improvement Program.

MAIN OUTCOME MEASURES

BMI was categorized into World Health Organization categories. Primary outcome was 30-day postoperative surgical site infection. Secondary outcomes included all American College of Surgeons National Surgical Quality Improvement Program-assessed 30-day postoperative complications.

RESULTS

Our cohort included 74,891 patients with 4.4% underweight (BMI <18.5), 29.0% normal weight (BMI 18.5-24.9), 33.0% overweight (BMI 25.0-29.9), 19.8% obesity class I (BMI 30.0-34.9), 8.4% obesity class II (BMI 35.0-39.9), and 5.5% obesity class III (BMI ≥40.0). Compared with normal-weight patients, obese patients experienced incremental odds of surgical site infection from class I to class III (I: OR = 1.5 (95% CI, 1.4-1.6); II: OR = 1.9 (95% CI, 1.7-2.0); III: OR = 2.1 (95% CI, 1.9-2.3)). Obesity class III patients were most likely to experience wound disruption, sepsis, respiratory or renal complication, and urinary tract infection. Mortality was highest among underweight patients (OR = 1.3 (95% CI, 1.0-1.8)) and lowest among overweight (OR = 0.8 (95% CI, 0.6-0.9)) and obesity class I patients (OR = 0.8 (95% CI, 0.6-1.0)).

LIMITATIONS

Retrospective analysis of American College of Surgeons National Surgical Quality Improvement Program hospitals may not represent patients outside of the American College of Surgeons National Surgical Quality Improvement Program and cannot assign causation or account for interventions to improve surgical outcomes.

CONCLUSIONS

Patients with increasing BMI showed an incremental and independent risk for adverse 30-day postoperative outcomes, especially surgical site infections. Strategies to address obesity preoperatively should be considered to improve surgical outcomes among this population. See Video Abstract at http://links.lww.com/DCR/A607.

Antimicrobial prophylaxis for colorectal surgery

BACKGROUND

Research shows that administration of prophylactic antibiotics before colorectal surgery prevents postoperative surgical wound infection. The best antibiotic choice, timing of administration and route of administration remain undetermined.

OBJECTIVES

To establish the effectiveness of antimicrobial prophylaxis for the prevention of surgical wound infection in patients undergoing colorectal surgery. Specifically to determine:1. whether antimicrobial prophylaxis reduces the risk of surgical wound infection;2. the target spectrum of bacteria (aerobic or anaerobic bacteria, or both);3. the best timing and duration of antibiotic administration;4. the most effective route of antibiotic administration (intravenous, oral or both);5. whether any antibiotic is clearly more effective than the currently recommended gold standard specified in published guidelines;6. whether antibiotics should be given before or after surgery.

SEARCH METHODS

For the original review published in 2009 we searched the Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library, MEDLINE (Ovid) and EMBASE (Ovid). For the update of this review we rewrote the search strategies and extended the search to cover from 1954 for MEDLINE and 1974 for EMBASE up to 7 January 2013. We searched CENTRAL on the same date (Issue 12, 2012).

SELECTION CRITERIA

Randomised controlled trials of prophylactic antibiotic use in elective and emergency colorectal surgery, with surgical wound infection as an outcome.

DATA COLLECTION AND ANALYSIS

Data were abstracted and reviewed by one review author and checked by another only for the single, dichotomous outcome of surgical wound infection. Quality of evidence was assessed using GRADE methods.

MAIN RESULTS

This updated review includes 260 trials and 68 different antibiotics, including 24 cephalosporins and 43,451 participants. Many studies had multiple variables that separated the two study groups; these could not be compared to other studies that tested one antibiotic and had a single variable separating the two groups. We did not consider the risk of bias arising from attrition and lack of blinding of outcome assessors to affect the results for surgical wound infection.Meta-analyses demonstrated a statistically significant difference in postoperative surgical wound infection when prophylactic antibiotics were compared to placebo/no treatment (risk ratio (RR) 0.34, 95% confidence interval (CI) 0.28 to 0.41, high quality evidence). This translates to a reduction in risk from 39% to 13% with prophylactic antibiotics. The slightly higher risk of wound infection with short-term compared with long-term duration antibiotic did not reach statistical significance (RR 1.10, 95% CI 0.93 to 1.30). Similarly risk of would infection was slightly higher with single-dose antibiotics when compared with multiple dose antibiotics, but the results are compatible with benefit and harm (RR 1.30, 95% CI 0.81 to 2.10). Additional aerobic coverage and additional anaerobic coverage both showed statistically significant improvements in surgical wound infection rates (RR 0.44, 95% CI 0.29 to 0.68 and RR 0.47, 95% CI 0.31 to 0.71, respectively), as did combined oral and intravenous antibiotic prophylaxis when compared to intravenous alone (RR 0.56, 95% CI 0.43 to 0.74), or oral alone (RR 0.56, 95% CI 0.40 to 0.76). Comparison of an antibiotic with anaerobic specificity to one with aerobic specificity showed no significant advantage for either one (RR 0.84, 95% CI 0.30 to 2.36). Two small studies compared giving antibiotics before or after surgery and no significant difference in this timing was found (RR 0.67, 95% CI 0.21 to 2.15). Established gold-standard regimens recommended in major guidelines were no less effective than any other antibiotic choice.

AUTHORS' CONCLUSIONS

This review has found high quality evidence that antibiotics covering aerobic and anaerobic bacteria delivered orally or intravenously (or both) prior to elective colorectal surgery reduce the risk of surgical wound infection. Our review shows that antibiotics delivered within this framework can reduce the risk of postoperative surgical wound infection by as much as 75%. It is not known whether oral antibiotics would still have these effects when the colon is not empty. This aspect of antibiotic dosing has not been tested. Further research is required to establish the optimal timing and duration of dosing, and the frequency of longer-term adverse effects such as Clostridium difficile pseudomembranous colitis.

A statewide colectomy experience: the role of full bowel preparation in preventing surgical site infection

OBJECTIVE

To assess the utility of full bowel preparation with oral nonabsorbable antibiotics in preventing infectious complications after elective colectomy.

BACKGROUND

Bowel preparation before elective colectomy remains controversial. We hypothesize that mechanical bowel preparation with nonabsorbable oral antibiotics is associated with a decreased rate of postoperative infectious complications when compared with no bowel preparation.

METHODS

Patient and clinical data were obtained from the Michigan Surgical Quality Collaborative-Colectomy Best Practices Project. Propensity score analysis was used to match elective colectomy cases based on primary exposure variable-full bowel preparation (mechanical bowel preparation with nonabsorbable oral antibiotics) or no bowel preparation (neither mechanical bowel preparation given nor nonabsorbable oral antibiotic given). The primary outcomes for this study were occurrence of surgical site infection and Clostridium difficile colitis.

RESULTS

In total, 2475 cases met the study criteria. Propensity analysis created 957 paired cases (n = 1914) differing only by the type of bowel preparation. Patients receiving full preparation were less likely to have any surgical site infection (5.0% vs 9.7%; P = 0.0001), organ space infection (1.6% vs 3.1%; P = 0.024), and superficial surgical site infection (3.0% vs 6.0%; P = 0.001). Patients receiving full preparation were also less likely to develop postoperative C difficile colitis (0.5% vs 1.8%, P = 0.01).

CONCLUSIONS

In the state of Michigan, full bowel preparation is associated with decreased infectious complications after elective colectomy. Within this context, the Michigan Surgical Quality Collaborative recommends full bowel preparation before elective colectomy.

Ring drape do not protect against surgical site infections in colorectal surgery: a randomised controlled study

INTRODUCTION

Surgical site infections (SSIs) remain a major problem in colorectal surgery.

METHOD

In this prospective, randomised study, we compared two kinds of wound protection, namely, "plastic ring drape" versus "standard cloth towels". One hundred one patients were randomised to the control group (wet cloth towels) and 98 to the study cohort (ring drape). SSIs were classified according to Centers for Disease Control and Prevention recommendations.

DISCUSSION

In the control group, 30 patients had an SSI, whereas 20 did so in the study group. This difference was not significant (p = 0.131).

CONCLUSION

Plastic ring drape for wound protection does not guard against SSIs in colorectal surgery.

A multicenter evaluation of the role of mechanical bowel preparation in pediatric colostomy takedown

BACKGROUND

In response to studies in adults that have failed to demonstrate a benefit for mechanical bowel preparation in colonic surgery, we sought to evaluate the utility of mechanical bowel preparation in a multicenter, retrospective study of children who underwent colostomy takedown.

METHODS

The records of 272 children who underwent colostomy takedown at 3 large children's hospitals were reviewed, and the utilization of mechanical bowel preparation and perioperative antibiotics was noted. Length of stay and the incidences of wound, anastomotic, and other complications were compared.

RESULTS

A polyethylene glycol bowel prep was administered to 187 children. All subjects received perioperative, intravenous antibiotics, and 52% of those with bowel preps received preoperative oral antibiotics. Subjects in the bowel prep group had a significantly higher incidence of wound infection (P = .04) and longer length of stay (P = .05). Oral antibiotics did not affect outcome.

CONCLUSIONS

The use of a mechanical bowel preparation in children before colostomy takedown was associated with a greater risk for wound infection, no protection from other complications, and a longer length of stay. This suggests that bowel preparation may be safely omitted in many children who undergo colonic surgery, thereby reducing cost and discomfort.

Bowel preparation for colectomy and risk of Clostridium difficile infection

BACKGROUND

Mechanical bowel preparation before colectomy is controversial for several reasons, including a theoretically increased risk of Clostridium difficile infection.

OBJECTIVE

The primary aim of this study was to compare the incidence of C difficile infection among patients who underwent mechanical bowel preparation and those who did not. A secondary objective was to assess the association between C difficile infection and the use of oral antibiotics.

DESIGN

This was an observational cohort study.

SETTING

The Michigan Surgical Quality Collaborative Colectomy Project (n = 24 hospitals) participates in the American College of Surgeons-National Surgical Quality Improvement Program with additional targeted data specific to patients undergoing colectomies.

PATIENTS

Included were adult patients (21 years and older) admitted to participating hospitals for elective colectomy between August 2007 and June 2009.

MAIN OUTCOME MEASURE

The main outcome measure was laboratory detection of a positive C difficile toxin assay or stool culture.

RESULTS

Two thousand two hundred sixty-three patients underwent colectomy and fulfilled inclusion criteria. Fifty-four patients developed a C difficile infection, for a hospital median rate of 2.8% (range, 0-14.7%). Use of mechanical bowel preparation was not associated with an increased incidence of C difficile infection (P = .95). Among 1685 patients that received mechanical bowel preparation, 684 (41%) received oral antibiotics. The proportion of patients in whom C difficile infection was diagnosed after the use of preoperative oral antibiotics was smaller than the proportion of patients with C difficile infection who did not receive oral antibiotics (1.6% vs 2.9%, P = .09).

LIMITATIONS

The potential exists for underestimation of C difficile infection because of the study's strict data collection criteria and risk of undetected infection after postoperative day 30.

CONCLUSIONS

In contrast to previous single-center data, this multicenter study showed that the preoperative use of mechanical bowel preparation was not associated with increased risk of C difficile infection after colectomy. Moreover, the addition of oral antibiotics with mechanical bowel preparation did not confer any additional risk of infection.

Differing risk factors for incisional and organ/space surgical site infections following abdominal colorectal surgery

OBJECTIVE

Surgical site infections are a major source of morbidity after colorectal surgery. The aim of this study was to explore differences between incisional and organ/space surgical site infection types by evaluating risk factors, National Nosocomial Risk Index Scores, and clinical outcomes.

DESIGN

A random sample of adults undergoing abdominal colorectal surgery between June 2001 and July 2008 was extracted from a colorectal surgery practice database. Patient factors, comorbidities, intraoperative factors, postoperative factors, and infection were collected; risk score (from -1 to 3 points) was calculated. Variables associated with surgical site infection by univariate analysis were incorporated in a multivariable model to identify risk factors by infection type. Infection risk by risk score was evaluated by logistic regression. Length of stay, readmission, and mortality were examined by infection type.

RESULTS

Six hundred fifty subjects were identified: 312 were male, age was 59.8 (SD 17.8) years. Common preoperative diagnoses included colorectal cancer (36.9%) and inflammatory bowel disease (21.7%). Forty-five cases were emergencies, and 171 included rectal resections. Eighty-two patients developed incisional and 64 developed organ/space surgical site infections. Body mass index was associated with incisional infection (OR 1.05, 95% CI 1.00-1.09), whereas previous radiation (OR 4.49, 95% CI 1.53-13.18), postoperative hyperglycemia (OR 2.99, 95% CI 1.41-6.34), preoperative [albumin] (OR 0.52, 95% CI 0.36-0.76), and case length (OR 1.26, 95% CI 1.08-1.47) were associated with organ/space infection. A risk score of 2 and above, compared with a score of <2, predicted organ/space (OR 5.92, 95% CI 3.16-11.09) but not incisional infection (OR 0.95, 95% CI 0.41-2.16). Organ/space infections were associated with longer length of stay (P = .006) and higher readmission rates (P < .001) than incisional infections.

CONCLUSIONS

Risk factors for surgical site infections differ by type of infection. Clinical outcomes and value of the risk index score are different by infection type. It may be prudent to consider incisional and organ/space surgical site infections as different entities for patients undergoing colorectal surgery.

Back to basics--cutting the cord on umbilical infections

INTRODUCTION

Surgical site infections (SSIs) are a significant cause of postoperative morbidity with laparoscopic surgery associated with lower SSI rates. However, a departmental change in our unit to increased laparoscopic colorectal surgery resulted in increased wound infection rates at umbilical specimen extraction sites, the cause of which we attempted to elucidate.

SUBJECTS AND METHODS

Prospectively collected data over an 18-month period (April 2008 to September 2009) for laparoscopic colorectal operations in a busy teaching hospital were retrospectively analysed, focusing on operation performed, whether pre-operative skin cleansing was employed, nature of specimen extraction excision, and rate of umbilical wound infection. Comparison was made with open colorectal procedures performed in the preceding year.

RESULTS

In total, 275 laparoscopic colorectal operations were performed. Over the first 8 months there was a significant increase in infection rates when compared with open procedures over a similar time period (23.5% vs 8.0%; P = 0.0001). Changing practice to use pre-operative skin cleansing and an incision that skirted around, as opposed to traversing, the umbilicus reduced umbilical infection rates significantly from 23.5% to 11.6% (P = 0.01). Patients undergoing right hemicolectomy benefitted more (reduction of 30.0% to 6.9%; P = 0.04) than those undergoing anterior resection (26.8% vs 15.6%, P = 0.13).

CONCLUSIONS

Umbilical incisions, when extended for specimen extraction, are particularly prone to infection following colorectal surgery but rates can be reduced by simple measures such as pre-operative umbilical cleansing and avoidance of the umbilicus in the incision, without the need for drastic and costly changes in technique or antibiotic prophylaxis.

Preoperative mechanical bowel preparation does not offer a benefit for patients who undergo pancreaticoduodenectomy

BACKGROUND

Mechanical bowel preparations (MBPs) are commonly administered preoperatively to patients who undergo pancreaticoduodenectomy (PD); however, their effectiveness over a clear liquid diet (CLD) preparation remains unclear. The aim of this study was to determine whether MBP offers an advantage to patients who undergo PD.

METHODS

In this retrospective review, we analyzed the clinical data from 100 consecutive PDs performed on patients who received preoperative MBP from March 2006 to April 2007, and we compared them with 100 consecutive patients who received a preoperative CLD from May 2007 to March 2008.

RESULTS

No differences were observed between the MBP and CLD groups in the rates of pancreatic fistula (13% vs 14%; P = 1.0), intra-abdominal abscess (11% vs 13%; P = .83), or wound infection (9% vs 8%; P = 1.0). Trends toward increased urinary tract infections (13% vs 5%; P < .08) and Clostridium difficile infections were found in the MBP group (6% vs 1%; P = .12). The median duration of postoperative hospital stay was 7 days in each group, and the 12-month survival rates were equivalent (74% vs 75%; P = 1.0).

CONCLUSION

There is no clinical benefit to the administration of a preoperative MBP for patients undergoing PD.