Economic burden of surgical site infections at a European university hospital

OBJECTIVE: To quantify the economic burden of in-hospital surgical site infections (SSIs) at a European university hospital. DESIGN: Matched case-control study nested in a prospective observational cohort study. SETTING: Basel University Hospital in Switzerland, where an average of 28,000 surgical procedures are performed per year. METHODS: All in-hospital occurrences of SSI associated with surgeries performed between January 1, 2000, and December 31, 2001, by the visceral, vascular, and traumatology divisions at Basel University Hospital were prospectively recorded. Each case patient was matched to a control patient by age, procedure code, and National Nosocomial Infection Surveillance System risk index. The case-control pairs were analyzed for differences in cost of hospital care and in provision of specialized care. RESULTS: A total of 6,283 procedures were performed: 187 SSIs were detected in inpatients, 168 of whom were successfully matched with a control patient. For case patients, the mean additional hospital cost was SwF-19,638 (95% confidence interval [CI], SwF-8,492-SwF-30,784); the mean additional postoperative length of hospital stay was 16.8 days (95% CI, 13-20.6 days); and the mean additional in-hospital duration of antibiotic therapy was 7.4 days (95% CI, 5.1-9.6 days). Differences were primarily attributable to organ space SSIs (n = 76). CONCLUSIONS: In a European university hospital setting, SSIs are costly and constitute a heavy and potentially preventable burden on both patients and healthcare providers.

Impact of intraoperative behavior on surgical site infections

BACKGROUND: The aim of this study was to identify intraoperative risk factors for surgical site infections (SSIs), which are accessible to interventions. We evaluated the effect of extensive intraoperative antiseptic measures and the impact of the behavior of members of the surgical team on SSIs. METHODS: Standard versus extensive antiseptic measures were randomly assigned in 1,032 surgical patients. The adherence to principles of asepsis by members of the surgical team was assessed prospectively. RESULTS: The rate of SSI was 14% with standard antiseptic measures and 15% with extensive measures (P = .581). Multivariate analysis identified following independent risk factors: lapses in discipline (odds ratio [OR] 2.02, confidence interval [CI] 1.05-3.88), intestinal anastomosis (OR 6.74, CI 3.42-13.30), duration of operation more than 3 hours (OR 3.34, CI 1.82-6.14), and body mass index >30 kg/m2 (OR 1.98, CI 1.22-3.20). CONCLUSION: Extensive measures of antisepsis did not reduce the incidence of SSI. A lapse to adhere to principles of asepsis was identified as an independent risk factor for the development of SSI (ClinicalTrials.gov number, NCT00555815).

The association of preoperative anemia and perioperative allogeneic blood transfusion with the risk of surgical site infection

BACKGROUND: The purpose of the study was to investigate allogeneic blood transfusion (ABT) and preoperative anemia as risk factors for surgical site infection (SSI). STUDY DESIGN AND METHODS: A prospective, observational cohort of 5873 consecutive general surgical procedures at Basel University Hospital was analyzed to determine the relationship between perioperative ABT and preoperative anemia and the incidence of SSI. ABT was defined as transfusion of leukoreduced red blood cells during surgery and anemia as hemoglobin concentration of less than 120 g/L before surgery. Surgical wounds and resulting infections were assessed to Centers for Disease Control standards. RESULTS: The overall SSI rate was 4.8% (284 of 5873). In univariable logistic regression analyses, perioperative ABT (crude odds ratio [OR], 2.93; 95% confidence interval [CI], 2.1 to 4.0; p < 0.001) and preoperative anemia (crude OR, 1.32; 95% CI, 1.0 to 1.7; p = 0.037) were significantly associated with an increased odds of SSI. After adjusting for 13 characteristics of the patient and the procedure in multivariable analyses, associations were substantially reduced for ABT (OR, 1.25; 95% CI, 0.8 to 1.9; p = 0.310; OR, 1.07; 95% CI, 0.6 to 2.0; p = 0.817 for 1-2 blood units and >or=3 blood units, respectively) and anemia (OR, 0.91; 95% CI, 0.7 to 1.2; p = 0.530). Duration of surgery was the main confounding variable. CONCLUSION: Our findings point to important confounding factors and strengthen existing doubts on leukoreduced ABT during general surgery and preoperative anemia as risk factors for SSIs.

Implantation of Prophylactic Nonabsorbable Intraperitoneal Mesh in Patients With Peritonitis Is Safe and Feasible

BACKGROUND: Patients with peritonitis undergoing emergency laparotomy are at increased risk for postoperative open abdomen and incisional hernia. This study aimed to evaluate the outcome of prophylactic intraperitoneal mesh implantation compared with conventional abdominal wall closure in patients with peritonitis undergoing emergency laparotomy. METHOD: A matched case-control study was performed. To analyze a high-risk population for incisional hernia formation, only patients with at least two of the following risk factors were included: male sex, body mass index (BMI) >25 kg/m(2), malignant tumor, or previous abdominal incision. In 63 patients with peritonitis, a prophylactic nonabsorbable mesh was implanted intraperitoneally between 2005 and 2010. These patients were compared with 70 patients with the same risk factors and peritonitis undergoing emergency laparotomy over a 1-year period (2008) who underwent conventional abdominal closure without mesh implantation. RESULTS: Demographic parameters, including sex, age, BMI, grade of intraabdominal infection, and operating time were comparable in the two groups. Incidence of surgical site infections (SSIs) was not different between groups (61.9 vs. 60.3 %; p = 0.603). Enterocutaneous fistula occurred in three patients in the mesh group (4.8 %) and in two patients in the control group (2.9 %; p = 0.667). The incidence of incisional hernia was significantly lower in the mesh group (2/63 patients) than in the control group (20/70 patients) (3.2 vs. 28.6 %; p < 0.001). CONCLUSIONS: Prophylactic intraperitoneal mesh can be safely implanted in patients with peritonitis. It significantly reduces the incidence of incisional hernia. The incidences of SSI and enterocutaneous fistula formation were similar to those seen with conventional abdominal closure.

Hepatic steatosis is associated with surgical-site infection after hepatic and colorectal surgery.

BACKGROUND Obesity and increased visceral fat deposits are important risk factors for surgical-site infection (SSI). Interestingly, a potential role of hepatic steatosis on complications after extrahepatic surgery remains unknown. The aim of the present study was to investigate the impact of hepatic steatosis on SSI in patients that underwent open abdominal surgery. METHODS A total of 231 patients that underwent either liver (n = 116) or colorectal (n = 115) resection and received preoperative contrast-enhanced computed tomography scans were retrospectively investigated. Signal attenuation of the liver parenchyma was measured on computed tomography scans to assess hepatic steatosis. RESULTS More SSIs (including types 1, 2, and 3) were found in the group with hepatic steatosis (56/118 [47.5%]) compared with the control group (30/113 [26.6%]; P = .001). Patients with hepatic steatosis showed greater median body mass index than patients without hepatic steatosis (26.6 kg/m(2) [range 16.8-47.0 kg/m(2)] vs 23.2 kg/m(2) [15.9-32.7 kg/m(2)]; P < .001). Patients with hepatic steatosis experienced longer median operation times (297 minutes [52-708 minutes] vs 240 minutes [80-600 minutes]; P = .003). In a multivariate analysis, hepatic steatosis was identified as an independent risk factor for SSI in patients undergoing hepatic (odds ratio 10.33 [95% confidence interval 1.19-89.76]; P = .03) or colorectal (odds ratio 6.67 [95% confidence interval 1.12-39.33]; P = .04) operation. CONCLUSION Hepatic steatosis is associated with SSI after hepatic and colorectal operation.

Additional surgical procedure is a risk factor for surgical site infections after laparoscopic cholecystectomy

PURPOSE: Surgical site infections (SSI) are associated with increased costs and length of hospital stay, readmission rates, and mortality. The aim of this study was to identify risk factors for SSI in patients undergoing laparoscopic cholecystectomy. METHODS: Analysis of 35,432 laparoscopic cholecystectomies of a prospective multicenter database was performed. Risk factors for SSI were identified among demographic data, preoperative patients' history, and operative data using multivariate analysis. RESULTS: SSIs after laparoscopic cholecystectomy were seen in 0.8 % (n = 291) of the patients. Multivariate analysis identified the following parameters as risk factors for SSI: additional surgical procedure (odds ratio [OR] 4.0, 95 % confidence interval [CI] 2.2-7.5), age over 55 years (OR 2.4 [1.8-3.2]), conversion to open procedure (OR 2.6 [1.9-3.6]), postoperative hematoma (OR 1.9 [1.2-3.1]), duration of operation >60 min (OR 2.5 [1.7-3.6], cystic stump insufficiency (OR 12.5 [4.2-37.2]), gallbladder perforation (OR 6.2 [2.4-16.1]), gallbladder empyema (OR 1.7 [1.1-2.7]), and surgical revision (OR 15.7 [10.4-23.7]. SSIs were associated with a significantly prolonged hospital stay (p < 0.001), higher postoperative mortality (p < 0.001), and increased rate of surgical revision (p < 0.001). CONCLUSIONS: Additional surgical procedure was identified as a strong risk factor for SSI after laparoscopic cholecystectomy. Furthermore, operation time >60 min, age >55 years, conversion to open procedure, cystic stump insufficiency, postoperative hematoma, gallbladder perforation, gallbladder empyema, or surgical revision were identified as specific risk factors for SSI after laparoscopic cholecystectomy.

4'-O-methylhonokiol increases levels of 2-arachidonoyl glycerol in mouse brain via selective inhibition of its COX-2-mediated oxygenation

BACKGROUND AND PURPOSE 4'-O-methylhonokiol (MH) is a natural product showing anti-inflammatory, anti-osteoclastogenic, and neuroprotective effects. MH was reported to modulate cannabinoid CB2 receptors as an inverse agonist for cAMP production and an agonist for intracellular [Ca2+]. It was recently shown that MH inhibits cAMP formation via CB2 receptors. In this study, the exact modulation of MH on CB2 receptor activity was elucidated and its endocannabinoid substrate-specific inhibition (SSI) of cyclooxygenase-2 (COX-2) and CNS bioavailability are described for the first time. METHODS CB2 receptor modulation ([35S]GTPγS, cAMP, and β-arrestin) by MH was measured in hCB2-transfected CHO-K1 cells and native conditions (HL60 cells and mouse spleen). The COX-2 SSI was investigated in RAW264.7 cells and in Swiss albino mice by targeted metabolomics using LC-MS/MS. RESULTS MH is a CB2 receptor agonist and a potent COX-2 SSI. It induced partial agonism in both the [35S]GTPγS binding and β-arrestin recruitment assays while being a full agonist in the cAMP pathway. MH selectively inhibited PGE2 glycerol ester formation (over PGE2) in RAW264.7 cells and significantly increased the levels of 2-AG in mouse brain in a dose-dependent manner (3 to 20 mg kg(-1)) without affecting other metabolites. After 7 h from intraperitoneal (i.p.) injection, MH was quantified in significant amounts in the brain (corresponding to 200 to 300 nM). CONCLUSIONS LC-MS/MS quantification shows that MH is bioavailable to the brain and under condition of inflammation exerts significant indirect effects on 2-AG levels. The biphenyl scaffold might serve as valuable source of dual CB2 receptor modulators and COX-2 SSIs as demonstrated by additional MH analogs that show similar effects. The combination of CB2 agonism and COX-2 SSI offers a yet unexplored polypharmacology with expected synergistic effects in neuroinflammatory diseases, thus providing a rationale for the diverse neuroprotective effects reported for MH in animal models.

Impact of case-relevant and case-irrelevant communication within the surgical team on surgical-site infection

BACKGROUND Surgical-site infections (SSIs) are the most common complications after surgery. An influence from talking and distractions during surgery on patient outcomes has been suggested, but there is limited evidence. The aim of this prospective observational study was to assess the relationship between intraoperative communication within the surgical team and SSI, and between intraoperative distractions and SSI. METHODS This prospective observational study included patients undergoing elective, open abdominal procedures. For each procedure, intraoperative case-relevant and case-irrelevant communication, and intraoperative distractions were observed continuously on site. The influence of communication and distractions on SSI after surgery was assessed using logistic regressions, adjusting for risk factors. RESULTS A total of 167 observed procedures were analysed; their mean(s.d.) duration was 4·6(2·1) h. A total of 24 SSIs (14·4 per cent) were diagnosed. Case-relevant communication during the procedure was independently associated with a reduced incidence of organ/space SSI (propensity score-adjusted odds ratio 0·86, 95 per cent c.i. 0·77 to 0·97; P = 0·014). Case-irrelevant communication during the closing phase of the procedure was independently associated with increased incidence of incisional SSI (propensity score-adjusted odds ratio 1·29, 1·08 to 1·55; P = 0·006). Distractions had no association with SSI. CONCLUSION More case-relevant communication was associated with fewer organ/space SSIs, and more case-irrelevant communication during wound closure was associated with incisional SSI.