Laparoscopic sigmoid colectomy and splenectomy for diverticulitis and splenic sarcoidosis.

Splenectomy together with colectomy is most commonly performed as a result of iatrogenic injury and not as an additional elective procedure. A 50-year-old African American female presented with recurrent episodes of diverticulitis. She had mediastinal, and porta hepatis lymphadenopathy and subcutaneous nodules, but multiple biopsies were unable to establish the diagnosis. On computed tomography scan, innumerable hypodense splenic lesions were noted. The patient underwent combined laparoscopic sigmoid colectomy and splenectomy. First, the severely inflamed sigmoid colon was mobilised followed by descending colon and splenic flexure. The spleen, which showed multiple granulomas, was dissected out and the hilum secured with a stapler. The rectum was now stapled, the Pfannenstiel incision was reopened, the spleen was removed in a retrieval bag and the colon was pulled out. The colorectal anastomosis was created with an end-to-end anastomotic (circular) stapler. Pathology demonstrated multiple non-caseating granulomas indicative for sarcoidosis and acute/chronic diverticulitis. The patient developed a superficial surgical site infection but no other complications. Prednisone and methotrexate were started and her sarcoidosis improved. She was well at her 2 years of follow-up. Only few patients have an indication for elective splenectomy together with segmental colectomy. The procedure can be safely performed using a laparoscopic approach.

Sex- and diagnosis-dependent differences in mortality and admission cytokine levels among patients admitted for intensive care.

OBJECTIVES: To investigate the role of sex on cytokine expression and mortality in critically ill patients. DESIGN: A cohort of patients admitted to were enrolled and followed over a 5-year period. SETTING: Two university-affiliated hospital surgical and trauma ICUs. PATIENTS: Patients 18 years old and older admitted for at least 48 hours to the surgical or trauma ICU. INTERVENTIONS: Observation only. MEASUREMENTS AND MAIN RESULTS: Major outcomes included admission cytokine levels, prevalence of ICU-acquired infection, and mortality during hospitalization conditioned on trauma status and sex. The final cohort included 2,291 patients (1,407 trauma and 884 nontrauma). The prevalence of ICU-acquired infection was similar for men (46.5%) and women (44.5%). All-cause in-hospital mortality was 12.7% for trauma male patient and 9.1% for trauma female patient (p = 0.065) and 22.9% for nontrauma male patients and 20.6% for nontrauma female patients (p = 0.40). Among trauma patients, logistic regression analysis identified female sex as protective for all-cause mortality (odds ratio, 0.57). Among trauma patients, men had significantly higher admission serum levels of interleukin-2, interleukin-12, interferon-γ, and tumor necrosis factor-α, and among nontrauma patients, men had higher admission levels of interleukin-8 and tumor necrosis factor-α. CONCLUSIONS: The relationship between sex and outcomes in critically ill patients is complex and depends on underlying illness. Women appear to be better adapted to survive traumatic events, while sex may be less important in other forms of critical illness. The mechanisms accounting for this gender dimorphism may, in part, involve differential cytokine responses to injury, with men expressing a more robust proinflammatory profile.

Experience with Laparoscopic and Robotic Colon Surgery Together with Other Major Minimally Invasive Procedures for Unrelated Pathologies.

Background: Indications for combined colon surgery together with other procedures include oncologic multivisceral resections and abdominal trauma. It is unclear if combining minimally invasive (MI) colon surgery with unrelated other procedures increases the risk for complications. Patients and Methods: The surgical database from two institutions during a 10-year period was queried for combined colon surgeries together with other interventions. All open cases, combined cases performed for one pathology and MI colectomies together with a minor procedure, were excluded. Results: Median age of the 6 men and 7 women was 64.4 (range 42.7-75.4) years. Colon surgeries included right (5), sigmoid (4) transverse (1) colectomies, rectum resection (1), rectopexy (1), and colostomy reversal (1) with indications of colorectal cancer (5), diverticulitis (3), benign ileocecal mass (1), colonic volvulus (3) and rectal prolapse (1). Second procedures included two splenectomies (sarcoidosis, ITP), paraesophageal hernia repairs (4), right diaphragmatic repairs [eventration (2) and Morgagni type hernia]; cholecystectomies (2), appendectomy (acute appendicitis), duodenal wedge resection (carcinoid), reversal of a gastric bypass (Roux limb stricture) one each. Cases were done laparoscopically (7) and robotic assisted (6). In most cases only 4 trocars were used. Median OR time was 4.3 (range 2.5 to 6.6) hours. No anastomotic breakdown was observed. Conclusions: Combining MI colectomy and other major abdominal surgeries can be safely done and in this series did not increase morbidity or mortality but avoids a second operation. Patient selection seems important and port placement may need to be altered to achieve good exposure for both procedures.

Vitamin C and Thiamin Deficiencies in Patients Undergoing Laparoscopic and Robotic Gastric Band Removal.

Outcomes after adjustable gastric banding (AGB) were unsatisfactory and many devices need to be removed for dysphagia. Vitamin C and thiamin deficiency are rare conditions in industrialized countries. Patients undergoing AGB removal (90% for dysphagia) from 2021 to 2023 (laparoscopic 15 and robotic 5) were tested for vitamin C and thiamin levels. Twenty patients (8 m/12 f median aged 56 (range 33.6-79.4) were included. BMI at AGB removal was 39.7 (range 24.4-50.1) kg/m2. Only 20% of patients had normal thiamin levels, 30% had low levels, 20% were deficient, and 30% were critically low. Only 25% of patients had normal vitamin C levels, 40% had low levels, 25% were deficient, and 10% were critically low. One third of patients had HbA1c levels between 5.8 and 6.4 and 22% had levels >6.5; 60% of patients had hyperlipidemia. Adjustable gastric banding patients develop concerning rates of vitamin C and thiamin deficiency, and routine testing for levels is recommended.

Acute Cholecystitis Due to Lactococcus lactis and Single-Center Experience With Infections Due to Lactococcus spp.

Background: Lactococcus species are used to ferment milk to yogurt, cheese, and other products. The gram-positive coccus causes diseases in amphibia and fish and is a rare human pathogen. Patients and Methods: A 51-year-old male underwent laparoscopic cholecystectomy for acute and chronic calculous cholecystitis. Lactococcus lactis was isolated from pus from his gallbladder empyema. Results: Our institutional database was searched for other cases of Lactococcus spp. infections and four patients (2 males, 2 females; aged 51, 64, 78, and 80 years) were identified during a four-year period. The three other patients had positive blood cultures associated with pneumonia, toxic megacolon, and severe gastroenteritis. All isolates were monocultures with Lactococcus lactis (2), Lactococcus garvieae (1) and Lactococcus raffinolactis (1). Two patients died related to their sepsis. We report the second case of cholecystitis involving Lactococcus. Conclusions: Lactococcus is a very rare pathogen mainly causing blood stream infections but needs to be considered to cause serious surgical infections in humans.

Hypothyroidism Complicated by Vitamin C and Thiamin Deficiency in Surgical Patients.

Multiple vitamin deficiencies together with endocrinopathy may be encountered in individuals presenting with critical illness. Following the surprise postmortem diagnosis of concomitant scurvy, Wernicke, and hypothyroidism in an elderly woman presenting with a mix of atypical symptoms, patients considered at risk were tested for TSH, vitamin C, and thiamin levels. Between September 1, 2018, and December 31, 2022, 801 vitamin C levels in 679 patients were measured in our rural hospital and 309 (39%) were found <0.4 mg/dL. In this population, 39% of 626 thiamin levels were found to be low. Twenty-two patients with vitamin C and/or thiamin deficiency and elevated TSH levels were identified. Two patients died from scurvy; one also had myxedema. The incidence of vitamin C and thiamin deficiency in our patient population was higher than expected. Further studies should determine if this is unique to our rural setting or part of a bigger trend associated with poor dietary choices.

Good Long-Term Outcome Following Liver Transplant in a Patient With Common Variable Immunodeficiency Syndrome Despite Multiple Infections and Recurrent Nodular Regenerative Hyperplasia.

Common variable immunodeficiency can be associated with various hepatic conditions, the most common being nodular regenerative hyperplasia. Multiple cases of liver transplant in adults with common variable immunodeficiency have been reported. Here, we report a 51-year-old man with common variable immunodeficiency and noncirrhotic portal hypertension due to nodular regenerative hyperplasia who underwent liver transplant. The patient received tacrolimus/steroid immunosuppression and remained rejection free; however, he developed cytomegalovirus infection, disseminated nocardiosis, Pseudomonas pneumonia, and Clostridioides difficile- associated colitis. All infections were successfully managed. The graft was well functioning after 18 months; however, alkaline phosphatase remained elevated and a liver biopsy showed evidence of recurrent nodular regenerative hyperplasia. The patient was started on a steroid taper, which led to normalization of the alkaline phosphatase. Two years later, a repeat biopsy confirmed recurrent nodular regenerative hyperplasia. Immunosuppression was kept low, and intravenous immunoglobulin infusions were continued. More than 10 years later, the patient is alive with a functioning graft. This case emphasizes that intensified prophylaxis for infections and less intense immunosuppression may be strategies to enable long-term survival in liver transplant recipients with common variable immunodeficiency and nodular regenerative hyperplasia relapse despite recently reported poor outcomes in this patient population.

Elderly recipients of hepatitis C positive renal allografts can quickly develop liver disease.

Our institution explored using allografts from donors with Hepatitis C virus (HCV) for elderly renal transplantation (RT). Thirteen HCV- elderly recipients were transplanted with HCV+ allografts (eD+/R-) between January 2003 and April 2009. Ninety HCV- elderly recipients of HCV- allografts (eD-/R-), eight HCV+ recipients of HCV+ allografts (D+/R+) and thirteen HCV+ recipients of HCV- allografts (D-/R+) were also transplanted. Median follow-up was 1.5 (range 0.8-5) years. Seven eD+/R- developed a positive HCV viral load and six had elevated liver transaminases with evidence of hepatitis on biopsy. Overall, eD+/R- survival was 46% while the eD-/R- survival was 85% (P = 0.003). Seven eD+/R- died during follow-up. Causes included multi-organ failure and sepsis (n = 4), cancer (n = 1), failure-to-thrive (n = 1) and surgical complications (n = 1). One eD+/R- died from causes directly related to HCV infection. In conclusion, multiple eD+/R- quickly developed HCV-related liver disease and infections were a frequent cause of morbidity and mortality.

Castleman disease in a pediatric liver transplant recipient: a case report and literature review.

Castleman disease is a rare hematologic disorder, closely linked to the HHV-8, and most commonly observed in immunocompromised individuals. Thirteen months following a liver transplant for CPS-1 defect, a 15-month-old boy presented with fevers, anemia, and growth retardation. Abdominal CT scan showed splenomegaly and generalized lymphadenopathy. Histology of chest wall lymph nodes revealed a mixed CD3+ T-cell and CD20+ B-cell population with atretic germinal centers consistent with multicentric Castleman disease. Qualitative DNA PCR detected HHV-8 in the resected lymph node and in the blood, supporting the diagnosis. Immunosuppression was tapered, and he was transitioned from tacrolimus to sirolimus. His graft function remained stable, and repeat imaging showed regression of the lymphadenopathy. The child is living one yr after Castleman disease diagnosis with a well-functioning graft. Castleman disease is a potential complication of solid organ transplant and HHV-8 infection. Reduction in immunosuppression and switch to sirolimus may be an effective strategy to treat this condition.

Acute Cholecystitis in a Gastric Bypass Patient Complicated by Takotsubo Cardiomyopathy.

Background: Gallbladder disease is a common condition after gastric bypass surgery. Even after weight loss, many bariatric patients continue to suffer from comorbid conditions. Takotsubo cardiomyopathy is a rare condition that mimics acute cardiac ischemia but seems to be caused by a catecholamine storm triggered by intense stress. Case Report. A 62-year-old female presented with acute right upper quadrant (RUQ) pain to the ER. She had a history of laparoscopic gastric bypass 5 years ago and had been noncompliant for 2 years. This noncompliance included missing follow-up appointments, gaining weight which caused poorly controlled DM, and not taking her vitamin supplements. Upon presentation, her WBC was elevated, her LFTs were normal, and imaging showed acute calculous cholecystitis. She was admitted and started on antibiotics with plans for laparoscopic cholecystectomy. The next day, she developed acute chest pain, and troponins were elevated with ST changes on EKG. Echocardiography showed a ballooned left ventricle indicative for Takotsubo cardiomyopathy. Symptomatic treatment including antibiotics, betablocker, and thiamine infusion was initiated. At three-month follow-up, ejection fraction had improved from <20% to >50%. The patient underwent interval laparoscopic cholecystectomy, which was technically very challenging due to severe ongoing acute and chronic cholecystitis. There were no cardiac issues, but the patient developed an abscess in the gallbladder fossa, which was successfully treated with oral antibiotics. Conclusions: Takotsubo cardiomyopathy complicating acute cholecystitis has thus far not been reported. Our patient had a history of gastric bypass and was noncompliant with vitamin supplementation. Thiamine deficiency may have contributed to the cardiac condition (wet beriberi).

Explanted liver inflammatory grade predicts fibrosis progression in hepatitis C recurrence.

UNLABELLED: Factors present prior to liver transplantation (LT) that predict fibrosis progression in recurrent hepatitis C infection (HCV) after LT would be important to identify. This study sought to determine if histologic grade of HCV in the explant predicts fibrosis progression in recurrent HCV. The clinical and histologic data of all 159 patients undergoing their first LT for HCV at our center from 1998 to 2001 were retrospectively reviewed with follow-up through June 2008. Twenty-five cases were excluded for: non-HCV-related graft loss <90 days (19), recidivism (4), or unavailable explant or follow-up biopsies (2). A single pathologist scored (Ishak) explants in a blinded fashion. Patients were grouped by explant inflammatory grade ≤ 4 (group1) and >4 (group 2). Prospectively scored liver biopsies (protocol months 1 and 4, annually, and as indicated clinically) were reviewed for development of advanced fibrosis (bridging or cirrhosis). Cox proportional hazard regression was used to analyze the association of explant grade, donor, viral and LT factors with progression to advanced fibrosis. The groups were well-matched for patient, viral, donor, and transplant factors. Five-year advanced fibrosis-free survival in group 1 versus group 2 was 63% versus 28%, P < 0.001. Explant grade >4 was associated with increased HCV-related graft loss at 1 (6% versus 3%) and 5 (36% versus 14%) years post-LT (P = 0.003). On univariate and multivariate Cox regression analysis, predictors of advanced fibrosis were explant grade >4 (hazard ratio [HR] = 3.3, 95% confidence interval [CI] = 1.9-5.6, P < 0.001) donor age >50 (HR = 3.3, 95% CI = 1.9-5.7, P < 0.001) and viral load at LT of >158,730 IU/mL (HR = 1.8, 95% CI = 1.05-3.1, P = 0.03). CONCLUSION: Explant histologic grade can identify patients requiring more aggressive monitoring and intervention for HCV recurrence post-LT.

Improving graft survival for patients undergoing liver transplantation.

Liver transplant (LT) outcomes are reported to be improving in non-HCV recipients but not for those infected with HCV. Our aim was to evaluate graft survival and predictors of outcome in HCV and non-HCV patients before and after 2003. Patients with primary LT between February 1, 1998, and December 31, 2005, were included. Patients were divided into Era 1 (1998-2002) and Era 2 (2003-2005) with follow-up through May 31, 2009. Graft survival was compared for HCV, non-HCV, and all patients. There was significant improvement in graft survival in Era 2 for HCV patients. Graft survival in Era 2 of HCV patients was equivalent to non-HCV patients. The most significant improvement between eras was in outcomes of grafts from donors ≥60 yr with three-yr graft survival 58.6 (51.3-65.9) vs. 75.4 (68.9-81.9), p = 0.002. The use of donors ≥60 did not change between eras: 31% vs. 34%; however, utilization in HCV recipients decreased from 36% to 3% (p < 0.001). In conclusion, graft survival of HCV patients has improved significantly since 2003 and was comparable to non-HCV patients up to three yr. The change in management of donor organs into HCV and non-HCV patients likely contributed to this outcome.

Real-time MR-guided retrieval of inferior vena cava filters: an in vitro and animal model study.

PURPOSE: To develop interventional magnetic resonance (MR) guidance techniques for inferior vena cava (IVC) filter retrieval in vitro and demonstrate feasibility in vivo. MATERIALS AND METHODS: Three optional IVC filters and their retrieval systems were investigated. Experiments were performed on a 1.5-T MR system. Real-time MR imaging was optimized by using a custom-built IVC phantom. A three-dimensional (3D) contrast-enhanced MR venography sequence was optimized in vitro for improved detection of thrombus trapped within the filters. Filters were then retrieved in vitro and in vivo in a swine model under MR guidance. In-vivo retrieval procedure time was measured. RESULTS: The combination of one of the nitinol filters and a loop snare was suitable for real-time MR procedures. With a 90° flip angle, 3D MR venography allowed detection of simulated thrombus within the filter. A radial true fast imaging sequence with steady-state precession allowed visualization of the loop snare and IVC filter hook and successful retrieval of the filter in vivo and in vitro. In-vivo MR fluoroscopy time for retrieval was 97 seconds ± 51 (mean ± SD). CONCLUSIONS: MR-guided retrieval of a nitinol-based IVC filter by using a loop snare is feasible with the use of optimized sequences and passive device tracking.

Laparoscopic Repair of Morgagni Hernia Combined with Right Hemicolectomy for Bleeding Ascending Colon Carcinoma Lodged within the Chest: A Case Report and Review of the Literature.

BACKGROUND: Morgagni hernias are rare in adults and may be asymptomatic but, nevertheless, require surgical repair, with laparoscopy offering an excellent option. The colon dislodged into the chest through diaphragmatic hernias may be affected by various disorders, including malignancies. Case Report. A 70-year-old obese male presented with fatigue and shortness of breath. CT scan showed the right colon lodged in the chest through a Morgagni hernia. He was anaemic, and colonoscopy revealed a colon cancer. He underwent combined laparoscopic hernia repair with bioabsorbable mesh and right hemicolectomy. Recovery was uneventful, but the patient died 5 months later from chemotherapy-associated cardiac failure. Literature review revealed eight similar published cases, and including ours, there were seven Morgagni hernias, one traumatic hernia, and one Bochdalek hernia. Median age of the five men and four women was 66 (range 49-85) years. Surgical approach was thoracotomy (2), laparotomy (5), and laparoscopy (2). CONCLUSION: Outcome of the rare condition is determined by the course of the colon cancer. Hernia repair was successful in ours and all other published cases. A combined laparoscopic approach can be safely done.

Appendiceal Diverticulitis in a Young Female Diagnosed on Pathology after Laparoscopic Appendectomy for Acute Appendicitis.

Background. Appendiceal diverticulitis is a rare cause of inflammation of the appendix, which may mimic acute appendicitis. Its diagnosis is often delayed, and its occurrence carries an increased risk of significant complications, such as perforation. Case Presentation. A 23-year-old woman presented with sudden onset, severe, right lower quadrant abdominal pain and nausea. Her WBC was elevated, and abdominal CT showed findings indicative of acute appendicitis with a 13 mm fluid-filled appendix and local stranding. During laparoscopic appendectomy, significant inflammation was found around the appendix with some mucous material around the tip. The appendix base was not involved, and an endoloop was used to secure the stump. No other intra-abdominal abnormalities were observed. The patient recovered uneventfully. Pathology showed no classic appendicitis but appendiceal diverticulitis with signs of perforation. Discussion. Appendiceal diverticulitis is a rare condition which cannot be distinguished from acute appendicits clinically and on imaging. Diagnosis may be established based on pathology such as in our case. Appendectomy is indicated in appendiceal diverticulitis, and an appendix diverticulum is incidentally found during surgery or other investigations. This is due to the increased risk of perforation and the reported development of malignant tumors, including the appendix carcinoid.

Portal Perfusion Through the Splenic Vein During Liver Procurement.

OBJECTIVES: Livers procured via donation after cardiac death have produced good outcomes. Some centers use only aortic perfusion; others add portal perfusion. MATERIALS AND METHODS: We report a series of organ procurements in which portal perfusion was performed via cannulation of the splenic vein instead of the inferior mesenteric vein in 4 donors after cardiac death and 2 donors after brain death. RESULTS: After declaration of death, donors were brought to the operating room and prepared and draped. During procurement, first the aorta was cannulated, and then the atrium or inferior vena cava was opened and perfusion was started.The spleen was mobilized, the splenic vein was dissected out and cannulated, and portal perfusion was performed with 2 L of University of Wisconsin solution. Five liver allografts were transplanted: 3 at our center, and 2 at outside centers. One liver from a donor after cardiac death was declined because of a high fat content. All 5 transplanted grafts showed good initial function; there was no sign of primary nonfunction, and no vascular or biliary complications developed. CONCLUSIONS: For livers from donors after cardiac death, cannulation of the splenic vein was easier than access via the inferior mesenteric vein. For donors after brain death, we also found this technique was suitable for livers with intra-abdominal adhesions or a small inferior mesenteric vein. Graft outcomes in this series were excellent.

A Series of Haemophilus parainfluenzae Surgical Infections and Review of the Literature.

Background: Haemophilus parainfluenzae (HPI) is a rare and underreported pathogen. Haemophilus parainfluenzae causes respiratory, soft tissue, and central nervous system (CNS) infections, and endocarditis. Little data on HPI surgical infections are available, especially for intra-abdominal infections (IAI). Patients and Methods: Haemophilus parainfluenzae isolates were recovered from patients treated at a rural hospital during a two-year period. Isolation and identification of the pathogen was done according to standard guidelines. A literature review with regard to HPI IAI was done. Results: A total of 273 HPI isolates were analyzed, 15 patients had double isolates; HPI was commonly part of a mixed infection. Respiratory tract infections accounted for 64.8%, ear-nose-throat (ENT)/eye infections for 17.9%, genital/urologic infections for 3%, blood stream infections for 1% of cases and 13.2% of HPI isolates involved surgical infections. Thirty-four patients (36 isolates) had HPI surgical infections including 28 skin/soft tissue infections, two bone infections, two perirectal abscesses, one infected hemodialysis catheter, and three IAIs including perforated appendicitis, perforated diverticulitis, and a pelvic abscess 10 days after laparoscopic appendectomy. All three IAIs were mixed infections and successfully managed with percutaneous drainage and antibiotic therapy. More than 90% of HPI isolates in our hospital tested negative for ß-lactamase production. A literature review revealed 32 reported cases of HPI IAI including biliary infections (12), peritonitis (9), liver abscess (7), and IA abscess (4) with the majority being monomicrobial; treatment included antibiotic agents and surgery/intervention in most cases. Outcomes were generally favorable. Conclusions: Our study confirms data from the literature that HPI is capable of causing a variety of severe surgical infections. More research with regard to this pathogen is warranted.

Longitudinal Gastrectomy for Nonbariatric Indications.

BACKGROUND: Sleeve gastrectomy is the most commonly performed bariatric procedure. Laparoscopic longitudinal gastrectomy (LLG) may be indicated for other indications. Patients and Methods. Two men and two women aged 67, 72, 77, and 80 years underwent LLG for nonbariatric indications with two having normal weight, one being cachectic, and one severely obese. RESULTS: LLG was discussed with patients prior to surgery, but decision for LLG was made during surgery after contemplating other surgical options. A wide sleeve over a 42 French bougie was created with the staple line being oversewn with running 3-0 silk. Indications included a bleeding Dieulafoy lesion that failed endoscopic clipping, fundus gland polyposis found during paraesophageal hernia repair, fundus nodules suspected to be leiomyosarcoma metastases revealing splenosis on final pathology, and significant gastric dilatation associated with organoaxial gastric volvulus. Three patients had an uneventful recovery; the severely obese patient temporarily lost weight but died after two years from a stroke. The last patient developed dysphagia due to an alpha-loop in the sleeve, which was managed by endoscopic stenting. The device subsequently migrated and was laparoscopically removed, with a side-side gastrogastrostomy performed to straighten the alpha-loop. The patient tolerated food better and with overnight PEG tube feeds gained weight but continued heavy smoking. He died after one year from COPD exacerbation. CONCLUSION: LLG seems to be an appropriate intervention for various gastric pathologies. Training of residents and fellows in the minimally invasive surgical steps of LLG is encouraged.

Identification of risk factors for the development of clostridium difficile-associated diarrhea following treatment of polymicrobial surgical infections.

OBJECTIVE: To identify risk factors for Clostridium difficile-associated diarrhea (CDAD) in surgical patients following treatment of polymicrobial infections. SUMMARY BACKGROUND DATA: Infections among surgical patients are frequently anaerobic or mixed aerobic-anaerobic infections and are therefore subject to polymicrobial antibiotic coverage, including metronidazole. While multiple antibiotics are known to contribute to the development of CDAD, the role of preventive antibiotics is unproven. METHODS: An 11-year dataset of consecutive infections treated in surgical patients at a single hospital was reviewed. All intra-abdominal, surgical site, or skin/skin structure infections were identified. Each infection was evaluated for antibiotic coverage and subsequent CDAD. Antibiotic usage was assessed using chi analysis. A multiple logistic regression was used to identify independent predictors of CDAD. RESULTS: A total of 4178 intra-abdominal, surgical site, or skin/skin structure infections were identified. Of these infections, 98 were followed by CDAD. Only carbapenem use affected the incidence of CDAD: 3.5% of infections treated with a carbapenem were followed by CDAD, whereas only 2.1% of infections treated without carbapenems were followed by CDAD (P = 0.04). Metronidazole had no association with future CDAD. Only age and Acute Physiology and Chronic Health Evaluation II (APACHE II) score were independently associated with CDAD by multiple logistic regression analysis. CONCLUSIONS: Older patients with a high severity of illness are at greatest risk for developing CDAD following treatment of polymicrobial infections. No specific antibiotic class, including fluoroquinolones, is associated with an increased incidence of CDAD in this population. Although use of metronidazole in the treatment of polymicrobial infections is appropriate for anaerobic coverage, it does not reduce the risk of future CDAD.