Risk of infection after penetrating abdominal trauma

Impact of laparoscopy on the perioperative outcome of penetrating abdominal trauma management during the post revolution period

BACKGROUND

Penetrating abdominal trauma (PAT) poses a significant challenge to trauma surgeons. Laparotomy is still the most popular procedure for managing PAT but has high morbidity and mortality rates. Presently, laparoscopy aims to provide equal or superior visualization compared to open approaches but with less morbidity, postoperative discomfort, and recovery time. The aim of this research is to assess the impact of laparoscopy on the management of PAT.

METHODS

This was a retrospective observational study carried out at the Emergency Hospital of Mansoura University/Egypt and at King Faisal Medical Complex, Taif/KSA from September 2014 to September 2018. All hemodynamically stable patients with PAT who were managed by laparoscopy were included in this study. Data extracted for analysis included demographic information, criteria of abdominal stabs, type of management, and perioperative outcome.

RESULTS

Forty patients were recruited in this research and the male-to-female ratio was 5.6:1. The mean age of the patients was 31.4 ± 12.318 years. During the laparoscopic procedure, no peritoneal penetration was observed in 4 patients (negative laparoscopy), while peritoneal penetration was observed in the remaining 36 patients. No visceral injuries were noted in 2 patients of the 36 patients with peritoneal penetration, while the remaining 34 patients had intra-abdominal injuries.

CONCLUSION

Laparoscopy performed on hemodynamically stable trauma patients was found to be safe and technically feasible. It also reduced negative and non-therapeutic laparotomies and offered paramount therapeutic and diagnostic advantages for traumatic diaphragmatic injuries.

Current status of initial antibiotic therapy and analysis of infections in patients with solitary abdominal trauma: a multicenter trial in Korea

Purpose

Proper use of antibiotics during emergency abdominal surgery is essential in reducing the incidence of surgical site infection. However, no studies have investigated the type of antibiotics and duration of therapy in individuals with abdominal trauma in Korea. We aimed to investigate the status of initial antibiotic therapy in patients with solitary abdominal trauma.

Methods

From January 2015 to December 2015, we retrospectively analyzed the medical records of patients with solitary abdominal trauma from 17 institutions including regional trauma centers in South Korea. Both blunt and penetrating abdominal injuries were included. Time from arrival to initial antibiotic therapy, rate of antibiotic use upon injury mechanism, injured organ, type, and duration of antibiotic use, and postoperative infection were investigated.

Results

Data of the 311 patients were collected. The use of antibiotic was initiated in 96.4% of patients with penetrating injury and 79.7% with blunt injury. Initial antibiotics therapy was provided to 78.2% of patients with solid organ injury and 97.5% with hollow viscus injury. The mean day of using antibiotics was 6 days in solid organ injuries, 6.2 days in hollow viscus. Infection within 2 weeks of admission occurred in 36 cases. Infection was related to injury severity (Abbreviated Injury Scale of >3), hollow viscus injury, operation, open abdomen, colon perforation, and RBC transfusion. There was no infection in cases with laparoscopic operation. Duration of antibiotics did not affect the infection rate.

Conclusion

Antibiotics are used extensively (84.2%) and for long duration (6.2 days) in patients with abdominal injury in Korea.

Antibiotic use in patients with abdominal injuries: guideline by the Korean Society of Acute Care Surgery

Purpose

A task force appointed by the Korean Society of Acute Care Surgery reviewed previously published guidelines on antibiotic use in patients with abdominal injuries and adapted guidelines for Korea.

Methods

Four guidelines were assessed using the Appraisal of Guidelines for Research and Evaluation II instrument. Five topics were considered: indication for antibiotics, time until first antibiotic use, antibiotic therapy duration, appropriate antibiotics, and antibiotic use in abdominal trauma patients with hemorrhagic shock.

Results

Patients requiring surgery need preoperative prophylactic antibiotics. Patients who do not require surgery do not need antibiotics. Antibiotics should be administered as soon as possible after injury. In the absence of hollow viscus injury, no additional antibiotic doses are needed. If hollow viscus injury is repaired within 12 hours, antibiotics should be continued for ≤ 24 hours. If hollow viscus injury is repaired after 12 hours, antibiotics should be limited to 7 days. Antibiotics can be administered for ≥7 days if hollow viscus injury is incompletely repaired or clinical signs persist. Broad-spectrum aerobic and anaerobic coverage antibiotics are preferred as the initial antibiotics. Second-generation cephalosporins are the recommended initial antibiotics. Third-generation cephalosporins are alternative choices. For hemorrhagic shock, the antibiotic dose may be increased twofold or threefold and repeated after transfusion of every 10 units of blood until there is no further blood loss.

Conclusion

Although this guideline was drafted through adaptation of other guidelines, it may be meaningful in that it provides a consensus on the use of antibiotics in abdominal trauma patients in Korea.

A Comparison of Self-Inflicted Stab Wounds Versus Assault-Induced Stab Wounds

Background

Although self-inflicted and assault-induced knife injuries might have different mortality and morbidity rates, no studies have actually evaluated the importance of the cause of knife injuries in terms of patient outcomes and treatment strategies.

Objectives

The aims of this study were to assess the difference between the outcomes of patients presenting with self-inflicted stab wounds (SISW) versus assault-induced stab wounds (AISW).

Patients and Methods

A retrospective review of the relevant electronic medical records was performed for the period between January 2000 and December 2012 for patients who were referred to the department of surgery for stab wounds by the trauma team. The patients were divided into either SISW (n = 10) or AISW groups (n = 11), depending on the cause of the injury.

Results

A total of 19 patients had undergone exploratory laparotomy. Of the nine patients with SISW undergoing this procedure, no injury was found in seven of the patients. In the AISW group, eight of the ten laparotomies were therapeutic. Three patients in the AISW group died during hospital admission. The average number of stab wounds was 1.2 for the SISW group and 3.5 for the AISW group. Organ injuries were more frequent in the AISW group, affecting the lung (2), diaphragm (3), liver (5), small bowel (2), colon (2), and kidney (1).

Conclusions

Although evaluations of the initial vital signs and physical examinations are still important, the history regarding the source of the stab wounds (AISW vs. SISW) may be helpful in determining the appropriate treatment methods and predicting patient outcomes.

Effect of initial empiric antibiotic therapy combined with control of the infection focus on the prognosis of patients with secondary peritonitis

BACKGROUND

In patients with intra-abdominal infection, inappropriate initial empiric antibiotic therapy is associated with greater morbidity. We evaluated the impact of adequate empiric antibiotic treatment together with control of the infection focus on the morbidity and mortality rates of patients with secondary peritonitis.

METHODS

This was a prospective, observational study with the participation of 24 Spanish hospitals and 362 patients with secondary peritonitis (262 community-acquired, 100 post-operative). Therapeutic failure (infectious complications or death) was classified into four categories according to whether empiric antibiotic treatment was appropriate and the infection focus was controlled.

RESULTS

The rates of therapeutic failure, re-operation, and mortality were 48%, 13%, and 8%, respectively. Empiric antibiotic treatment was inappropriate in 39% of cases, which was associated with a higher rate of surgical site infection (53% vs. 40%; p=0.031) and death (12% vs. 5%; p=0.021) than was observed in patients receiving appropriate initial empiric therapy. Eight percent of patients in whom control of the infection focus was not obtained suffered from more infectious complications (76% vs. 52%; p=0.01) and surgical site infections (69% vs. 44%; p=0.01); and in this group, both therapeutic failure and mortality rates were similar, independent of whether the empiric antibiotic therapy was appropriate.

CONCLUSION

Inappropriate initial empiric antibiotic therapy was associated with higher rates of therapeutic failure, surgical site infection, re-operation, and death. Classification of therapeutic failure into four categories according to the appropriateness of empiric antibiotic therapy and the success of infection control provided excellent discrimination of morbidity and death.

Prediction of multiple infections after severe burn trauma: a prospective cohort study

OBJECTIVE

To develop predictive models for early triage of burn patients based on hypersusceptibility to repeated infections.

BACKGROUND

Infection remains a major cause of mortality and morbidity after severe trauma, demanding new strategies to combat infections. Models for infection prediction are lacking.

METHODS

Secondary analysis of 459 burn patients (≥16 years old) with 20% or more total body surface area burns recruited from 6 US burn centers. We compared blood transcriptomes with a 180-hour cutoff on the injury-to-transcriptome interval of 47 patients (≤1 infection episode) to those of 66 hypersusceptible patients [multiple (≥2) infection episodes (MIE)]. We used LASSO regression to select biomarkers and multivariate logistic regression to built models, accuracy of which were assessed by area under receiver operating characteristic curve (AUROC) and cross-validation.

RESULTS

Three predictive models were developed using covariates of (1) clinical characteristics; (2) expression profiles of 14 genomic probes; (3) combining (1) and (2). The genomic and clinical models were highly predictive of MIE status [AUROCGenomic = 0.946 (95% CI: 0.906-0.986); AUROCClinical = 0.864 (CI: 0.794-0.933); AUROCGenomic/AUROCClinical P = 0.044]. Combined model has an increased AUROCCombined of 0.967 (CI: 0.940-0.993) compared with the individual models (AUROCCombined/AUROCClinical P = 0.0069). Hypersusceptible patients show early alterations in immune-related signaling pathways, epigenetic modulation, and chromatin remodeling.

CONCLUSIONS

Early triage of burn patients more susceptible to infections can be made using clinical characteristics and/or genomic signatures. Genomic signature suggests new insights into the pathophysiology of hypersusceptibility to infection may lead to novel potential therapeutic or prophylactic targets.

Peri-operative blood transfusion in gastric cancer surgery: prognostic or confounding factor?

BACKGROUND AND PURPOSE

The relationship between peri-operative blood transfusions (PBTs) and poor prognosis in gastric cancer (GC) patients is still debated. The aim of this study is to examine the real prognostic impact of PBTs in comparison to well-known prognostic factors.

METHODS

We retrospectively analyzed a series of 224 patients who underwent surgery with curative intent for GC from January 1995 to December 2011. Among 224 patients, 46 (20%) required PBTs.

RESULTS

The overall 5-year survival was 77% in non-transfused patients and 65% in patients who received PBTs (p = 0.03). PBTs did not further stratify any recognized prognostic category (such as pT or pN according to the 7th edition of the TNM staging system). Multivariate analysis including all known prognostic variables (both cancer- and non-cancer-related) did not select PBTs as an independent prognostic factor. Only preoperative hemoglobin and albumin level, pT and operative time were significantly associated with the requirement for PBTs.

CONCLUSIONS

The study showed a worse prognosis for transfused patients, but PBTs seem a confounding factor more than a prognostic indicator, as they are obviously affected by other variables.

Prophylactic antibiotic use in penetrating abdominal trauma: an Eastern Association for the Surgery of Trauma practice management guideline

BACKGROUND

The use of prophylactic antibiotics in penetrating abdominal trauma has resulted in decreased infection rates. The Eastern Association for the Surgery of Trauma (EAST) first published its practice management guidelines (PMGs) for the use of prophylactic antibiotics in penetrating abdominal trauma in 1998. During the next decade, several new prospective studies were published on this topic. In addition, the practice of damage control laparotomy became widely used, and additional questions arose as to the role of prophylactic antibiotics in this setting. Thus, the EAST Practice Management Guidelines Committee set out to update the original PMG.

METHODS

A search of the National Library of Medicine and the National Institutes of Health MEDLINE databases was performed using PubMed (www.pubmed.gov) and specific key words. The search retrieved English language articles regarding the use of antibiotics in penetrating abdominal trauma published from 1973 to 2011. The topics investigated were the need for perioperative antibiotics, the duration of antibiotic therapy, the dose of antibiotics in patients presenting in hemorrhagic shock, and the appropriate duration of antibiotic therapy in the setting of damage control laparotomy.

RESULTS

Forty-four articles were identified for inclusion in this review.

CONCLUSION

There is evidence to support a Level I recommendation that prophylactic antibiotics should only be administered for 24 hours in the presence of a hollow viscus injury. In addition, there are no data to support continuing prophylactic antibiotics longer than 24 hours in damage control laparotomy.

"SCIP"ping antibiotic prophylaxis guidelines in trauma: The consequences of noncompliance

OBJECTIVE

The Surgical Care Improvement Project (SCIP) established surgical antibiotic prophylaxis guidelines as part of a national patient safety initiative aimed at reducing surgical complications such as surgical site infection (SSI). Although these antibiotic prophylaxis guidelines have become well established in surgical patients, they remain largely unstudied in patients with injury from trauma undergoing operative procedures. We sought to determine the role of these antibiotic prophylaxis guidelines in preventing SSI in patients undergoing trauma laparotomy.

METHODS

A retrospective review of all patients who underwent emergency trauma laparotomy at two Level I trauma centers (2007-2008) revealed 306 patients who survived more than 4 days after injury. Demographics and clinical risk SSI factors were analyzed, and patients were compared on the basis of adherence to the following SCIP guidelines: (1) prophylactic antibiotic given, (2) antibiotic received within 1 hour before incision, (3) correct antibiotic selection, and (4) discontinuation of antibiotic within 24 hours after surgery. The primary study end point was the development of SSI.

RESULTS

The study sample varied by age (mean [SD], 32 [16] years) and injury mechanism (gunshot wound 44%, stab wound 27%, blunt trauma 30%). When patients with perioperative antibiotic management complying with the four SCIP antibiotic guidelines (n = 151) were compared with those who did not comply (n = 155), no difference between age, shock, small bowel or colon resection, damage control procedures, and skin closure was detected (p > 0.05). After controlling for injury severity score, hypotension, blood transfusion, enteric injury, operative duration, and other potential confounding variables in a multivariate analysis, complete adherence to these four SCIP antibiotic guidelines independently decreased the risk of SSI (odds ratio, 0.43; 95% confidence interval, 0.20-0.94; p = 0.035). Patients adhering to these guidelines less often developed SSI (17% vs. 33%, p = 0.001) and had shorter overall hospital duration of antibiotics (4 [6] vs. 9 [11] days, p < 0.001) and hospital length of stay (14 [13] vs. 19 [23] days, p = 0.016), although no difference in mortality was detected (p > 0.05).

CONCLUSIONS

Our results suggest that SCIP antibiotic prophylaxis guidelines effectively reduce the risk of SSI in patients undergoing trauma laparotomy. Despite the emergent nature of operative procedures for trauma, efforts to adhere to these antibiotic guidelines should be maintained.

Prognostic factors for traumatic bowel injuries: killing time

BACKGROUND

Intestinal rupture/perforation after abdominal trauma is a rare complication, but it is related to significant morbidity and mortality. Our objective is to identify determinants of prognosis in patients surgically treated for a bowel injury (small bowel and colon) after abdominal trauma.

METHODS

The present study is a retrospective analysis of 102 patients seen at our hospital during a 10-year period in whom laparotomy for traumatic bowel injury was performed. Predictors for morbidity and mortality were assessed in univariate and multivariate analysis models.

RESULTS

Mean age at diagnosis was 40 years, and most patients were male. There was a slight preponderance of blunt abdominal trauma, and the most frequent mechanism of injury was motor vehicle accident. In 75% of patients there was a small bowel lesion, and the colon was affected in 47%. There was no statistical relation between stoma construction and mortality, but an increase in morbidity was ultimately dependent on the severity of the underlying trauma. The univariate determinants of mortality were the new injury severity score (NISS) and American Society of Anesthesiologists (ASA) scores, the presence of blunt trauma and multiple intestinal or extra-abdominal lesions, and the elapsed time to surgery. The occurrence of postoperative complications was related to all these factors, as well as to tachycardia, hypotension, and bleeding. In multivariate analysis ASA score (p = 0.015), NISS (p = 0.002), time to surgery (p = 0.007), and presence of colonic lesions (p = 0.02) were identified as independent prognostic factors for postoperative morbidity.

CONCLUSIONS

The only modifiable determinant of morbidity seems to be the time to surgery. Only an expeditious evaluation and diagnosis and prompt surgical intervention can improve the prognosis of these patients.

Prevention of infections associated with combat-related thoracic and abdominal cavity injuries

Trauma-associated injuries of the thorax and abdomen account for the majority of combat trauma-associated deaths, and infectious complications are common in those who survive the initial injury. This review focuses on the initial surgical and medical management of torso injuries intended to diminish the occurrence of infection. The evidence for recommendations is drawn from published military and civilian data in case reports, clinical trials, meta-analyses, and previously published guidelines, in the interval since publication of the 2008 guidelines. The emphasis of these recommendations is on actions that can be taken in the forward-deployed setting within hours to days of injury. This evidence-based medicine review was produced to support the Guidelines for the Prevention of Infections Associated With Combat-Related Injuries: 2011 Update contained in this supplement of Journal of Trauma.

Surgical site infection in abdominal trauma patients: risk prediction and performance of the NNIS and SENIC indexes

BACKGROUND

The National Nosocomial Infections Surveillance (NNIS) and Efficacy of Nosocomial Infection Control (SENIC) indexes are designed to develop control strategies and to reduce morbidity and mortality rates resulting from infections in surgical patients. We sought to assess the application of these indexes in patients undergoing surgery for abdominal trauma and to develop an alternative model to predict surgical site infections (SSIs).

METHODS

We conducted a prospective cohort study between November 2000 and March 2002. The main outcome measure was SSIs. We evaluated the variables included in the NNIS and SENIC indexes and some preoperative, intraoperative and postoperative variables that could be risk factors related to the development of SSIs. We performed multivariate analyses using a forward logistic regression method. Finally, we assessed infection risk prediction, comparing the estimated probabilities with actual occurrence using the areas under the receiver operating characteristic (ROC) curves.

RESULTS

Overall, 614 patients underwent an exploratory laparotomy. Of these, 85 (13.8%) experienced deep incisional and organ/intra-abdominal SSIs. The independent variables associated with this complication were an Abdominal Trauma Index score greater than 24, abdominal contamination and admission to the intensive care unit. We proposed a model for predicting deep incisional and organ/intra-abdominal SSIs using these variables (alternative model). The areas under the ROC curves were compared using the estimated probabilities for this alternative model and for the NNIS and SENIC scores. The analysis revealed a greater area under the ROC curve for the alternative model. The NNIS and SENIC scores did not perform as well as the alternative model in patients with abdominal trauma.

CONCLUSION

The NNIS and SENIC indexes were inferior to the proposed alternative model for predicting SSIs in patients undergoing surgery for abdominal trauma.

Recent trends in the use of antibiotic prophylaxis in pediatric surgery

AIMS

The use of surgical antibiotic prophylaxis (AP) in children is poorly characterized. The aims of this study were to examine (1) trends in the use of AP for commonly performed operations, (2) appropriateness in the context of available guidelines, and (3) adverse events potentially attributable to AP.

METHODS

We conducted a 5-year retrospective analysis of 22 children's hospitals (January 2005-March 2009) for all patients younger than 18 years who underwent 1 of the 40 commonly performed general and urological procedures. Indications for AP were defined by published specialty-specific guidelines. Clostridium difficile infection and surrogate events for drug allergy (diphenhydramine and epinephrine administrations) were examined as potential antibiotic-associated adverse events.

RESULTS

Procedures of 246,316 were identified, of which 25% met criteria for AP. Eighty-two percent of the children received antibiotics during procedures when AP was indicated (range, 60%-96% by hospital), and 40% of the patients received antibiotics when there was no indication (range, 10%-83%). The likelihood of receiving AP was significantly different between hospitals for all procedures examined (P < .0001 for each procedure). Adverse events were significantly more frequent in children receiving AP than in those who did not (odds ratio [95% confidence interval] C difficile: 18.8 [6.9-51.5], P < .0001; epinephrine: 1.8 [1.7-2.0], P < .0001; diphenhydramine: 6.0 [5.6-6.5], P < .0001).

CONCLUSIONS

Significant variation exists in the use of AP in the pediatric surgical population. Many children do not receive AP when indicated, and an even greater proportion may receive antibiotics when there is no indication. These findings may have profound implications from a public health perspective when extrapolated to all children undergoing surgical procedures.

Microbiological profile and antimicrobial susceptibility in surgical site infections following hollow viscus injury

INTRODUCTION

The purpose of this study was to assess the microbiological profile, antimicrobial susceptibility, and adequacy of the empiric antibiotic therapy in surgical site infections (SSI) following traumatic hollow viscus injury (HVI).

METHODS

This is a retrospective study of patients admitted with an HVI from March 2003 to July 2009. SSI was defined as a wound infection or intra-abdominal collection confirmed by positive cultures and requiring percutaneous or surgical drainage.

RESULTS

A total of 91 of 667 (13.6%) patients with an HVI developed an SSI confirmed by positive culture. Mean age was 33.0 +/- 14.1 years, mean Injury Severity Score (ISS) was 17.7 +/- 9.6, 91.2% were male, and 80.2% had sustained penetrating injuries. The SSI consisted of 65 intra-abdominal collections and 26 wound infections requiring intervention. The most commonly isolated species in the presence of a colonic injury was Escherichia coli (64.7%), Enterococcus spp. (41.2%), and Bacteroides (29.4%), and in the absence of a colonic perforation, Enterococcus spp. and Enterobacter cloacae (both 38.9%). Susceptibility rates of E. coli and E. cloacae, respectively, were 38% and 8% for ampicillin/sulbactam, 82% and 4% for cefazolin, 96% and 92% for cefoxitin, with both 92% to piperacillin/tazobactam, and 100% to ertapenem. The initial empirical antibiotic therapy adequately targeted the pathogens in 51.6% of patients who developed an SSI.

CONCLUSION

The distribution of the microorganisms isolated from SSIs differed significantly according to whether or not a colonic injury was present. Empiric antibiotic treatment was inadequate in upwards of 50% of patients who developed an SSI. Further investigation is warranted to determine the optimal empiric antibiotic regimen for reducing the rate of postoperative SSI.

Trauma sepsis

Sepsis is a major cause of mortality and morbidity in the trauma patient. Sepsis following traumatic injury is related to the type of injury, together with the extent of injury and the anatomical location. Burn injuries are associated with the highest risk of sepsis. The diagnosis of sepsis in the trauma patient remains difficult. Interpretation of abnormal results is key to successful diagnosis, particularly in conjunction with clinical findings. This review will consider the specific features of sepsis in the context of trauma relating to epidemiology, risk factors, diagnosis and management.

Gastrointestinal hemorrhage: should we transfuse less?

Although blood transfusion has an established place in the conventional management of acute upper gastrointestinal (GI) hemorrhage, there is growing evidence of adverse side effects of transfusion, both acute and later. An Ovid Medline literature search was performed to evaluate the significance and importance of these effects. Evidence of impaired hemostasis with repletion of blood volume in the acute phase was found in multiple studies and in uncontrolled studies in combat casualties. There are multiple large studies of a so-called immunosuppressive effect of transfused blood leading to increased infection rates and mortality dependent both on dose and on the age of the stored blood. In view of evidence of increased bleeding with early blood volume restoration and the growing evidence of so-called immunosuppressive effects of stored blood, there is a need to consider trials using a conservative utilization of blood in acute GI bleeding.

Transfusion, Not Just Injury Severity, Leads to Posttrauma Infection: A Matched Cohort Study

Blood transfusion has been associated with infection; however, the collinearity of injury severity has not been clearly addressed to show a direct relationship. Using more rigorous analysis, we aimed to untangle the effect of injury severity from transfusion leading to sepsis. We hypothesized that blood transfusion independently increases infection in massively transfused versus nontransfused patients with matched Injury Severity Scores (ISSs). We performed a matched cohort study measuring infection rates in trauma patients receiving massive transfusion. Control subjects were contemporaneous patients with matched ISS receiving no blood. Infection was defined as intraperitoneal or intrathoracic abscesses, pneumonia, urinary tract infection, or bacteremia. Multivariate logistic and univariate analysis was completed. Infection rate was 61 per cent in 44 transfused patients versus 20 per cent in 44 control subjects ( P = 0.001). Odds of infection were eightfold greater in transfused patients (OR, 7.97; 95% CI, 2.3 to 27.5; P < 0.001) independent of ISS, Glasgow Coma Scale, mechanism, and age. Infection was most associated with transfusion of packed red blood cells (PRBCs), although transfusion of other blood products had strong collinearity with PRBCs. Transfused patients had eight times the risk of infection independent of ISS; this appears to be the result of PRBC transfusion. Modifying the ratio of components in transfusion protocols favoring plasma may cause less infection after injury

Commentary: Transfusions: weighing the risks and benefits

This commentary identifies important differences in patient groups that affect the observations in the accompanying article.

The impact of perioperative blood transfusion on clinical outcomes in colorectal surgery

Colorectal cancer is the second-leading cause of cancer-related death in the US. The prognosis of advanced colorectal cancer remains poor in spite of the advances obtained in recent years with new therapeutic agents, new approaches in surgical procedures and new diagnostic methods. Currently, colorectal cancer is the second most common cancer in Europe both in terms of incidence and mortality. Approximately 90% of all cancer deaths arise from the metastatic dissemination of primary tumors. It is a matter of vital importance whether perioperative blood transfusion promotes tumor recurrence and morbidity. This paper reviews the relevant medical literature published in English language on the theoretical background, methodological problems, results, as well as the possible clinical impact of blood transfusions in colorectal surgery with well-controlled trials. Searches were last update August 2007.

Post-traumatic hypotension: should systolic blood pressure of 90-109 mmHg be included?

It is generally accepted that patients with a systolic blood pressure (SBP)<90 mmHg are in "shock" and have a worse prognosis than patients with a higher SBP. Our objective was to determine if patients with a SBP of 90-109 mmHg have a worse outcome than patients with a higher SBP following trauma. Patients with gastric, small bowel, and/or diaphragm injuries were identified retrospectively through the trauma database from 1980-2003. All 2071 patients underwent emergent laparotomy at an urban, level one trauma center. The mortality rate of patients with a SBP of 90-109 mmHg in the ED or OR was 5% (17/354) and significantly higher than the 1% (12/1020) mortality seen in patients with a SBP of 110 mmHg or greater (P<0.001). The average length of stay of patients with a SBP of 90-109 mmHg was 15+/-14 days and was significantly longer than the 11+/-11 days seen in patients with a higher SBP. If the SBP was 90-109 mmHg, the infection rate was 39% (131/340), and this was significantly higher than the 22% (219/1016) infection rate seen in patients with higher SBP (P<0.001). Trauma patients with a systolic blood pressure of 109 mmHg or below are at increased risk for morbidity and mortality following trauma. Patients with a systolic blood pressure of 90-109 mmHg following trauma should be considered as a special group requiring aggressive resuscitation and surgery. Early operative control of hemorrhage in these patients can reduce mortality and infection.

Postoperative infections after oesophageal resections: the role of blood transfusions

BACKGROUND

Perioperative blood transfusion carries numerous potential risks concerning the transmission of infective diseases and immunodepression that can facilitate the occurrence of postoperative infectious complications. Explanation of connections between perioperative blood transfusion and postoperative septic complication worldwide is not well documented. Many studies have described a correlation between perioperative blood transfusions and postoperative infections. On the contrary, other studies indicate that factors influencing the need for blood transfusions during surgery have a greater bearing than blood transfusion per se on the occurrence of postoperative complications.

PATIENTS AND METHODS

A prospective study was conducted in our Department on 110 consecutive patients undergoing oesophageal resection for primary cancer, in order to evaluate the incidence of postoperative infections related to perioperative allogenic blood transfusions. For each patient we preoperatively recorded in a computerized data-base several known risk-factors for postoperative infections; in detail we registered the administration of allogenic perioperative blood transfusions (period of administration, number of packages administered).

RESULTS

Among the enrolled 110 patients, 53 (48%) received perioperative blood transfusions: in this group postoperative infections (overall infective complications) occurred in 27 patients. After a multivariate analysis we observed that perioperative blood transfusions significantly affected as an independent variable the development of wound infections (p = 0.02).

CONCLUSION

Blood transfusions independently affected the incidence of wound infections in patients who underwent oesophageal resection for primary cancer.

Mountainbiker's hematuria: a case report

Although exercise-induced hematuria is a well known finding in long distance running, it is extremely rare in cycling. We describe a case of gross atraumatic hematuria after mountainbiking. The only pathologic finding in our patient was a small hyperemic zone in the bladder mucosa suggesting a local traumatic origin due to repeated contact of the flaccid bladder wall against the bladder base. This in contrast with the renal origin commonly seen in marathon runners. It is a benign hematuria that usually resolves within a day without specific treatment. The best treatment is prevention by means of good bladder filling. Neoplasm of the urothelium should be ruled out in differential diagnosis.

Massive transfusion as a risk factor for acute lung injury: Association or causation?

One of the most common clinical sequelae of massive transfusion is acute lung injury. In virtually all clinical settings, there is a very strong relationship between transfusion and acute lung injury that remains even after adjusting for potential confounders. Whether the association between transfusion and acute lung injury in these settings is a result of residual confounding or actually reflects a causal relationship is unknown. However, there are several potential mechanisms by which massive transfusion might predispose to lung injury: a) cognate antigen-antibody interactions (classic transfusion-associated lung injury); b) activation of nonspecific immunity through soluble mediators present in transfused blood; c) an increased risk of infection through transfusion-associated immunomodulation leading to sepsis and sepsis-induced lung injury; and d) volume overload in the face of increased permeability of the alveolar capillary membrane. Elucidating the precise causal mechanism operative in patients receiving massive transfusion has more than academic importance; it has direct implications for transfusion policy and practice.

Granulocyte colony-stimulating factor prophylaxis improves survival and inflammation in a two-hit model of hemorrhage and sepsis

OBJECTIVE

We evaluated the effects of a granulocyte-colony stimulating factor (G-CSF) prophylaxis in two clinically relevant situations, hemorrhage on the day before infection (e.g., trauma) and acute hemorrhage followed subsequently by infection (e.g., operative complication). A two-hit model of hemorrhage and polymicrobial peritoneal contamination and infection (PCI) was used to assess the influence of G-CSF on the outcome, bacterial clearance, and cytokine pattern.

DESIGN

Clinic modeling randomized laboratory trial.

SETTING

University laboratory.

SUBJECTS

One hundred thirty-two male rats.

INTERVENTIONS

In trial 1 we compared a) preoperative PCI only; b) preoperative hemorrhage plus PCI; and c) hemorrhage plus PCI plus G-CSF prophylaxis (n=18 rats/group). In trial 2, intraoperative hemorrhage was assessed with the same trial design. Primary end point was survival at 120 hrs. In trial 2 additionally, six rats per group and six naive control rats were used for secondary end point analysis.

MEASUREMENTS AND MAIN RESULTS

Primary end point was mortality at 120 hrs. Secondary end points were granulocyte counts, bacterial clearance, and local cytokine levels. In trial 1 survival rate was 56% after PCI only, 17% after hemorrhage plus PCI, and 61% after hemorrhage plus PCI plus G-CSF (p<.01). In trial 2 survival rate was 33% after PCI only, 17% after hemorrhage plus PCI, and 50% after hemorrhage plus PCI plus G-CSF (p<.05). In trial 2, neutrophil counts were doubled to 66% 1 hr after hemorrhage (p<.05), colony-forming units of microbes in the lung and liver were halved to 166+/-56 and 134+/-28 colony-forming units (p<.05 for liver), and the macrophage inflammatory protein-2 expression in the lung was halved to 0.88+/-0.06 pg of complementary DNA (p<.05) by G-CSF prophylaxis compared with hemorrhage and PCI.

CONCLUSIONS

Hemorrhage (first hit) sensitized the host for a second hit of polymicrobial PCI independent of the timing. G-CSF prophylaxis improved survival and clearance of microbes and reduced the proinflammatory chemokine macrophage inflammatory protein-2 in the lung.

Surgical Site Infections

This article examines the epidemiology and risk factors for the development of surgical site infections (SSIs), the importance of appropriate administration of prophylactic antibiotics, nonpharmacologic strategies, and the role of new "active" devices in reducing SSIs. A review of the pertinent English-language literature shows that many factors contribute to the risk of a patient developing an SSI. These include the patient's health status, preparation of the patient before surgery, and the use of appropriate antibiotic prophylaxis. Careful preparation of the patient and care after surgery is especially important. The use of new "active" antibacterial devices may reduce risk further. Surgeons can minimize the risk to the patient of the development of SSI through strict adherence to established surgical guidelines for perioperative care.

Raised cortisol:DHEAS ratios in the elderly after injury: potential impact upon neutrophil function and immunity

The detrimental effect of stress on the immune response increases with age, though the mechanisms responsible are not fully understood. The physiological response to stress is regulated in part by the adrenocortical system. Adrenal hormones dehydroepiandrosterone sulphate (DHEAS) and cortisol have opposing effects on the innate immune system, DHEAS enhances while cortisol suppresses immunity and the molar ratio of cortisol to DHEAS increases with age. We found that elderly hip fracture patients produced a robust neutrophilia after injury, but circulating neutrophils showed an impaired antibacterial response. We therefore proposed that adrenocortical hormones mediate the heightened immunosuppression seen in the elderly after injury. We examined neutrophil function and adrenocortical hormone levels in elderly (> 65 years) hip fracture patients and age-matched healthy controls. Thirteen out of 35 elderly patients acquired infections following hip fracture. Neutrophil superoxide production was lower in elderly hip fracture patients compared with controls (P < 0.005) and lower in patients who acquired infection following injury compared with those who did not (P < 0.05). Serum cortisol:DHEAS ratio was higher in elderly hip fracture patients (0.56 +/- 0.38) compared with either age-matched controls (0.36 +/- 0.21; P < 0.05) or young fracture patients (0.087 +/- 0.033; P < 0.0001). Moreover, cortisol: DHEAS was increased in elderly patients who succumbed to infection compared with those who did not (0.803 +/- 0.42 vs. 0.467 +/- 0.28; P < 0.02). In vitro cortisol significantly decreased neutrophil superoxide generation (P < 0.05) and this was prevented by coincubation with DHEAS. We propose that increased cortisol:DHEAS ratios may contribute to reduced immunity following physical stress in the elderly.

Transfusion of the injured patient: proceed with caution

Transfusion of the injured patient with packed red blood cells (PRBCs) is a dynamic process requiring vigilance during the acute resuscitative and recovery phases postinjury. Although adverse events have been reported in 2% to 10% of injured patients, the advent of new detection techniques for viral pathogens has markedly decreased the risk of infectious transmission. However, transfusions are strongly associated with immunosuppression in the host, which may occur days after the initial injury and may lead to bacterial infections. Conversely, early transfusion of stored PRBCs, > 6 units in the first 12 h postinjury, contributes to an early state of hyperinflammation that is a strong, independent predictor of multiple organ failure (MOF) in those patients with intermediate injury severity scores. The roles of prestorage leukoreduction are also reviewed with respect to the promotion of both immunosuppression and hyperinflammation. We further summarize studies with hemoglobin substitutes, whose use may obviate many of the untoward events of transfusion and promise to lead to better outcomes for injured patients.

Transfusions result in pulmonary morbidity and death after a moderate degree of injury

BACKGROUND

Prior studies have suggested that blood transfusion (Tx) is associated with infectious and respiratory complications in trauma patients. However, these studies are difficult to interpret because of small sample size, inclusion of severely injured patients in traumatic shock, and combination of a variety of unrelated low-morbidity/mortality infections, such as wound, catheter-related, and urinary tract infection as outcomes. To eliminate these confounding variables, this study evaluates the association between delayed Tx and serious, well-defined respiratory complications (ventilator-associated pneumonia [VAP] and acute respiratory distress syndrome [ARDS]) and death in a cohort of intensive care unit (ICU) admissions with less severe (Injury Severity Score [ISS] < 25) blunt trauma who received no Tx within the initial 48 hours after admission.

METHODS

Patients with blunt injury and ISS < 25 admitted to the ICU over a 7-year period were identified from the registry and excluded if within 48 hours from admission they received any Tx or if they died. VAP required quantitative bronchoalveolar lavage culture (> or =10(5) colonies/mL), and ARDS required Pao2/Fio2 ratio < 200 mm Hg, *** no congestive heart failure, diffuse bilateral infiltrates, and peak airway pressure > 50 cm H2O for diagnosis. Outcomes were VAP, ARDS, and death.

RESULTS

Nine thousand one hundred twenty-six with blunt injury were ICU admissions, and 5,260 (58%) met study criteria (72% male). Means for age, ISS, and Glasgow Coma Scale score were 39, 12, and 14, respectively. There were 778 (15%) who received delayed Tx. Incidences of VAP, ARDS, and death were 5%, 1%, and 1%, respectively. Logistic regression analysis identified age, base excess, chest Abbreviated Injury Scale score, ISS, and any transfusion as significant predictors for VAP; chest Abbreviated Injury Scale score and transfusion as significant predictors for ARDS; and age and transfusion as significant predictors for death.

CONCLUSION

Delayed transfusion is independently associated with VAP, ARDS, and death in trauma patients regardless of injury severity. These data mandate a judicious transfusion policy after resuscitation and emphasize the need for safe and effective blood substitutes and transfusion alternatives.

Reversing systemic inflammatory response syndrome with chemokine receptor pepducins

We describe a new therapeutic approach for the treatment of lethal sepsis using cell-penetrating lipopeptides-termed pepducins-that target either individual or multiple chemokine receptors. Interleukin-8 (IL-8), a ligand for the CXCR1 and CXCR2 receptors, is the most potent endogenous proinflammatory chemokine in sepsis. IL-8 levels rise in blood and lung fluids to activate neutrophils and other cells, and correlate with shock, lung injury and high mortality. We show that pepducins derived from either the i1 or i3 intracellular loops of CXCR1 and CXCR2 prevent the IL-8 response of both receptors and reverse the lethal sequelae of sepsis, including disseminated intravascular coagulation and multi-organ failure in mice. Conversely, pepducins selective for CXCR4 cause a massive leukocytosis that does not affect survival. CXCR1 and CXCR2 pepducins conferred nearly 100% survival even when treatment was postponed, suggesting that our approach might be beneficial in the setting of advanced disease.

Cost-effectiveness of recombinant human erythropoietin for reducing red blood cells transfusions in critically ill patients

OBJECTIVE

To examine the cost-effectiveness of using recombinant human erythropoietin (rHuEPO) to reduce red blood cells (RBC) transfusions in intensive care unit (ICU) patients.

METHODS

Decision analysis examining costs and effectiveness of using rHuEPO versus not using rHuEPO in a simulated adult medical/surgical/trauma (mixed) ICU. Two independent cost-effectiveness models were created based on the results of two multicenter studies that investigated the use of rHuEPO. Base case assumptions and estimates of effectiveness were obtained from these two studies. Mean cumulative doses of rHuEPO were 190,900 units and 102,400 units for studies 1 and 2, respectively. The models accounted for the deferral rate for allogeneic RBC transfusions, rHuEPO efficacy (the reduction in allogeneic RBC use), and adverse effects of rHuEPO and allogeneic RBC transfusions. Model estimates were obtained from published sources. Costs were expressed in 2002 US dollar (dollars) and effectiveness was measured using discounted quality-adjusted life-years (QALYs). A 3% discount rate was used. Probabilistic sensitivity analysis was conducted using second-order Monte Carlo simulation.

RESULTS

Incremental costs of using rHuEPO to reduce RBC transfusions amounted to 1918 dollars and 1439 dollars; incremental effectiveness values were 0.0563 QALYs and 0.0305 QALYs; and the cost-effectiveness ratios were 34,088 dollars and 47,149 dollars per QALY for studies 1 and 2, respectively. The model was most sensitive to the attributable risk of nosocomial bacterial infections per RBC unit. rHuEPO was cost-effective in 52.0% of the Monte Carlo simulations for a willingness to pay of 50,000 dollars/QALY.

CONCLUSION

rHuEPO appears to be cost-effective for reducing RBC transfusions in heterogeneous ICU populations, assuming RBC transfusions increase the risk of nosocomial bacterial infections.

Anemia, allogenic blood transfusion, and immunomodulation in the critically ill

Anemia and allogenic RBC transfusions are exceedingly common among critically ill patients. Multiple pathologic mechanisms contribute to the genesis of anemia in these patients. Emerging risks associated with allogenic RBC transfusions including the transmission of newer infectious agents and immune modulation predisposing the patient to infections requires reevaluation of current transfusion strategies. Recent data have suggested that a restrictive transfusion practice is associated with reduced morbidity and mortality during critical illness, with the possible exception of acute coronary syndromes. In this article, we review the immune-modulatory role of allogenic RBC transfusions in critically ill patients.

A handicap in treatment and follow-up of ankylosing spondylitis: sports hematuria

A 19-year-old male patient with a 7-year history of ankylosing spondylitis (AS) was admitted to our clinic. After completion of the laboratory and radiologic investigations, we prescribed an exercise program besides his medical therapy. After these exercises, he complained of painless dark urine sometimes with passage of clot that disappeared the following day. To investigate this hematuria related with exercise, further laboratory and radiologic studies were carried out. After exclusion of the other causes of hematuria, we concluded that the diagnosis was sports hematuria.

Current strategies for prevention of surgical site infections

Surgical site infections (SSIs) are a common complication that follows all types of operative procedures. These infections are usually caused by the exogenous and endogenous microorganisms that enter the operative wound during the course of surgery. The general and procedure-specific risk factors for the development of SSI have been identified and are discussed in this article. Factors that influence the SSI rate and the current strategies for prevention of SSIs are also presented. Emphasis is placed on the efficacious use of antibiotic prophylaxis in surgery. A discussion of the principles of antibiotic prophylaxis, including choice of agents, route of administration, and timing, is offered. It appears that the use of less invasive laparoscopic surgical approaches, as practiced widely today, will be associated with an overall decreased incidence of SSI.

Stress responses and innate immunity: aging as a contributory factor

Evolutionary pressure has selected individuals with traits that allow them to survive to reproduction, without consideration of the consequences for the post-child rearing years and old age. In the 21st century, society is populated increasingly by the elderly and with the falling birth rate and improved health care this trend is set to continue for the foreseeable future. To minimize the potential burden on health services one would hope that 'growing old gracefully' should also mean 'growing old healthily'. However, for too many the aging process is accompanied by increasing physical and mental frailty producing an elevated risk of physical and psychological stress in old age. Stress is a potent modulator of immune function, which in youth can be compensated for by the presence of an optimal immune response. In the elderly the immune response is blunted as a result of the decline in several components of the immune system (immune senescence) and a shifting to a chronic pro-inflammatory status (the so-called 'inflamm-aging' effect). We discuss here what is known of the effects of both stress and aging upon the innate immune system, focusing in particular upon the age-related alterations in the hypopituitary-adrenal axis. We propose a double hit model for age and stress in which the age-related increase in the cortisol/sulphated dehydroepiandrosterone ratio synergizes with elevated cortisol during stress to reduce immunity in the elderly significantly.

Use of exogenous erythropoietin in critically ill patients

OBJECTIVE

Review the literature regarding the use of recombinant human erythropoietin (rHuEPO) to prevent red blood cell (RBC) transfusion in critically ill patients.

DATA SOURCES

A computerized search of MEDLINE and EMBASE from 1966 through June 2003 was conducted using the terms erythropoietin, anemia, hemoglobin, critical care, intensive care, surgery, trauma, burn, and transfusion. References of selected articles were reviewed. A manual search of critical care, surgery, trauma, burn, hematology, and pharmacy journals was conducted to identify relevant abstracts.

RESULTS

Six randomized studies have evaluated exogenous administration of erythropoietin to prevent RBC transfusions in critically ill patients. Studies vary with respect to rHuEPO dosage regimens, dose of concurrently administered iron, patient characteristics, and transfusion thresholds. Administration of rHuEPO rapidly produces erythropoiesis to reduce the need for RBC transfusions. The largest study conducted to date used weekly rHuEPO administration and found a modest decrease in transfusion requirements although the time to first transfusion was delayed. Reduced intensive care unit (ICU) length of stay (LOS) was shown in only one study of surgical/trauma patients. Reduced LOS after ICU discharge was found in another study of severely ill patients (APACHE II score >22). Other clinical outcomes were not altered by rHuEPO use. No adverse events were associated with rHuEPO use although studies were not designed to evaluate safety.

CONCLUSIONS

rHuEPO reduces the need for transfusions. A cost-effectiveness analysis of rHuEPO for this indication is needed. Defining an optimal dosage regimen, identifying patients most likely to respond to rHuEPO, and determining risk factors for ICU associated anaemia would provide information for appropriate rHuEPO utilization.

Preventing surgical site infections

Over the past 50 years, increased interest in the discipline of surgical infection has resulted in advances in post-surgical infection control. Early investigations focused on the importance of anaerobic microflora to postoperative infection and paved the way for significant improvements in prophylactic and therapeutic antibiotic treatment of surgical patients. Later research centered on the identification of risk factors to better predict postoperative infection rates. This article reviews the evolution of postoperative infection control and highlights antibiotic prophylaxis in specific clinical situations.

Bedside Laparotomy for Trauma: Are There Risks?

BACKGROUND

Critically ill trauma patients are often too unstable for safe transfer to the operating room. Damage control laparotomy patients frequently require early reoperation and have a reported mortality of 50-60%. As a result, many of these patients must undergo laparotomy in the intensive care unit. We hypothesized that patients undergoing bedside laparotomy (BSL) and managed with the abdomen left open would have an unacceptably high mortality or intra-abdominal complications.

METHODS

We performed a retrospective chart review of our Trauma Registry. Of the 11,096 consecutive trauma admissions from March 1, 1996 to May 20, 2000, 75 patients underwent 95 BSL. Patients were stratified according to injury severity score (ISS), base deficit (BD), lactic acid (LA), total transfusion (TRBC) requirements, indication for BSL, mechanism of injury, infectious complications (intra-abdominal abscess (IAA), fistula), and length of hospital stay.

RESULTS

Seventy-five patients underwent 95 BSL. Mean ISS was 50.6 +/- 18.9, mean BD was -11.9 (+/- 5), and the mean LA was 5 +/- 5 for the study group. The TRBC for the group was 43.7 +/- 42.6 units. Indications for the 95 BSL were (1) abdominal compartment syndrome (n = 47, 49.5%); (2) suspected intra-abdominal infection (n = 18, 19.0%); (3) washout/pack removal (n = 14, 14.7%); (4) washout with fascial closure (n = 12, 12.6%); and (5) other (n = 4, 4.2%). Twenty-nine of 75 patients (39.2%; ISS 52.3 +/- 18.8) died within 72 h of operation. Of the 46 remaining patients, an additional eight died 72 h or more after operation, for a late mortality rate of 17.4% and a total mortality rate of 49%. None of these deaths were attributable to either the operation or to post-operative IAA or fistula formation; all late deaths were secondary to multiple organ failure. Intra-abdominal abscesses developed in three of 46 patients (6.5%), each of whom had a TRBC of >100 units (mean, 160 units). Five of 46 patients (10.9%) developed enterocutaneous fistulae. None of these eight patients died. Thirty-eight of 75 patients (50.7%) survived to discharge, with a mean ISS of 40 (+/- 11.9).

CONCLUSIONS

Despite the high acuity of the population undergoing BSL, 50.7% of patients survived. Moreover, during BSL, IAA and fistula formation occurred at low rates.

Transfusion in pediatrics

In reviewing the literature, the authors noted an important variation in stated and observed transfusion practice patterns among pediatric critical care practitioners, and in published guidelines on RBC transfusion. They also noted a paucity of clinical evidence with respect to RBC transfusion to critically ill children. There has been only one large randomized trial in adults, and the authors do not believe that the results from this trial should be generalized to critically ill children because of the many differences in children and their adaptive responses, and differences in disease processes. More research about anemia and RBC transfusion to critically ill children must be performed. The TRIPICU study is testing the safety of giving more or less RBC transfusion to stable critically ill children. Other studies must be done on the epidemiology and determinants of RBC transfusion in PICUs, on prevention of transfusion, and on alternatives to RBC transfusion (eg, erythropoietin).

Prediction of 6-month survival after liver transplantation using Cox regression

BACKGROUND

The outcome of liver transplantation (LTx) has been correlated with several donor and recipient factors.

METHODS

A database of 191 consecutive LTx cases was analyzed using Kaplan-Meier and Cox regression statistics based on 80 variables. To avoid additional effects of late events on patient survival, the chosen endpoint was 6 months. Data were evaluated using SPSS statistical software.

RESULTS

Kaplan-Meier analysis revealed a difference in 1- to 6-month graft survival between patients transplanted with organs from donors older versus younger than 60 years (Breslow, P <.01). Differences in 1- to 6-month graft survivals were observed between patients listed as UNOS status 3, 2B, 2A, and 1: the outcomes for UNOS status 2B versus UNOS status 2A and UNOS status 2B versus status 1 were significant (P <.05). Differences in 1- to 6-month graft survival rates were found between patients with versus without sepsis (P <.05), and with versus without rejection episodes (P <.01). Cox regression analysis revealed only three of the variables to be independent prognostic predictors of graft failure: donor age; postoperative septic status; and rejection. The best mathematical multivariate Cox regression model linked donor age + donor Na + rejection + sepsis to 1- to 6-month graft survival (chi-square = 29.06, P <.001).

CONCLUSION

Factors predictive of 1- to 6-month graft survival after liver transplantation include donor age; UNOS status; sepsis; and rejection.

The consequences of suppression of anaerobic bacteria

Anaerobic bacteria such as Bacteroides fragilis, Peptostreptococcus species, and Fusobacterium species, when accompanied by aerobic bacteria or in the presence of dead tissue, can cause severe infections. This article discusses the most common type of anaerobic infection, i.e., infection after colonic contamination of the abdominal cavity and soft tissues. Colonic anaerobes rarely cause infections as solitary pathogens. Mixed infections of aerobes and anaerobes are treated by source control, surgical drainage and debridement, and combination antibiotic therapy. Antimicrobial treatment should cover both anaerobes and aerobes; treatment of mixed infections with anti-anaerobic agents alone is likely to result in abscess formation. Recent trends toward cost cutting and the advent of antibiotics with good coverage of both aerobes and relevant pathogenic anaerobes have led to increased single-agent therapy with cefoxitin, cefotetan, ampicillin/sulbactam, imipenem/cilastatin, ticarcillin/clavulanate, trovafloxacin/alatrofloxacin, and piperacillin/tazobactam. In the past 15 years, research has begun to focus on the gut barrier, particularly on the beneficial effects of anaerobic microflora. Directing antibiotic therapy against the anaerobe when it is involved in clinical infection is important; however, the negative consequences of anti-anaerobic antibiotic therapy on the beneficial effects of normal distal gut colonization must also be considered.