CDC definitions of nosocomial surgical site infections, 1992: a modification of CDC definitions of surgical wound infections

Linkage of microbiology reports and hospital discharge diagnoses for surveillance of surgical site infections

Surveillance of surgical site infections (SSIs) with feedback to surgical personnel is pivotal in decisions regarding infection control. Prospective surveillance is time and resource consuming, so we aimed to evaluate a method based on data collected routinely during care delivery. The study was carried out at three acute hospitals in North-eastern Italy, from 1 January 2001 to 31 December 2001. Hospital discharge diagnoses (selected codes from the International Classification of Diseases, 9th Revision--Clinical Modification) and electronic microbiology reports (positive cultures from surgical wounds and drainages) were linked to identify suspected SSIs. A random sample of tracked events was submitted to total chart review in order to confirm the presence of SSIs retrospectively according to Centers for Disease Control and Prevention definitions. Of 865 suspected SSIs, 64.5% were identified from the microbiological database, 27.1% from discharge codes, and 8.4% from both. Four hundred and three admissions were sampled for review; the overall positive predictive value was 72% (95%CI=69-76%). Since inpatient individual antibiotic exposure is not registered in Italy, the combined use of discharge codes and microbiology reports represents the most feasible automated method for surveillance of SSIs developing during hospital stay.

Rapid serodiagnosis of Staphylococcus aureus surgical site infection following median sternotomy

OBJECTIVES

To determine the sensitivity and specificity of a novel ELISA for the serodiagnosis of surgical site infection (SSI) due to staphylococci following median sternotomy.

METHODS

Twelve patients with a superficial sternal SSI and 19 with a deep sternal SSI due to Staphylococcus aureus were compared with 37 control patients who also underwent median sternotomy for cardiac surgery but exhibited no microbiological or clinical symptoms of infection. A further five patients with sternal SSI due to coagulase-negative (CoNS) staphylococci were studied. An ELISA incorporating a recently recognised exocellular short chain form of lipoteichoic acid (lipid S) recovered from CoNS, was used to determine serum levels of anti-lipid S IgG in all patient groups.

RESULTS

Serum anti-lipid S IgG titres of patients with sternal SSI due to S. aureus were significantly higher than the control patients (P<0.0001). In addition, patients with deep sternal SSI had significantly higher serum anti-lipid S IgG titres than patients with superficial sternal SSI (P = 0.03). Serum anti-lipid S IgG titres of patients with sternal SSI due to CoNS were significantly higher than the control patients (P = 0.001).

CONCLUSION

The lipid S ELISA may facilitate the diagnosis of sternal SSI due to S. aureus and could also be of value with infection due to CoNS.

Adverse impact of surgical site infections in English hospitals

Between October 1997 and June 2001, 140 English hospitals participating in the surveillance of surgical site infection (SSI) with the Nosocomial Infection National Surveillance Service (NINSS) reported 2832 SSIs following 67 410 surgical procedures in nine defined categories of surgery. Limb amputation had the highest incidence of SSI with 14.3 SSIs per 100 operations. For all categories of surgery, except knee prosthesis (P=0.128), there was a linear increase in the incidence of SSI when the American National Nosocomial Infections Surveillance risk index increased. Superficial incisional SSI was more common than deep incisional and organ/space SSI, and accounted for more than half of all SSIs for all categories of surgery. The postoperative length of stay (LOS) was longer for patients with SSI, and when adjusted for other factors influencing LOS, the extra LOS due to SSI ranged from 3.3 days for abdominal hysterectomy to 21.0 days for limb amputation, and was at least nine days for the other categories. The additional cost attributable to SSI ranged from pound959 for abdominal hysterectomy to pound6103 for limb amputation. Deep incisional and organ/space SSI combined incurred a greater extra LOS and cost than superficial incisional SSI for all categories of surgery, except limb amputation. The crude mortality rate was higher for patients with SSI for all categories of surgery but, after controlling for confounding, only patients with SSI following hip prosthesis had a mortality rate that was significantly higher than those without SSI [odds ratio (OR)=1.8, P=0.002]. However, the adjusted mortality rate for patients with deep incisional and organ/space SSI compared with those without SSI was significantly higher for vascular surgery (OR=6.8, P<0.001), hip prosthesis (OR=2.5, P=0.005) and large bowel surgery (OR=1.8, P=0.04). This study shows that the adverse impact of SSI differs greatly for different categories of surgery, and highlights the importance of measuring the impact for defined categories rather than for all SSIs and all surgical procedures.

Risk factors for prediction of surgical site infections in "clean surgery"

BACKGROUND

The aim of this study was to determine the risk factors of surgical site infections (SSI) in clean surgery and to identify high- and low-risk patients from whom efficacy of the antibiotic prophylaxis was analyzed.

METHODS

From June 1982 to September 1996, a database was established from 3 prospective multicenter randomized studies, containing information of 5798 patients who underwent abdominal noncolorectal surgery. Multivariate analysis was performed using nonconditional logistic regression expressed as an odds ratio (OR).

RESULTS

A total of 2374 patients underwent a clean surgery. An antibiotic prophylaxis was administered to 1943 patients (81.8%). A multivariate analysis was performed including only preoperative factors and disclosed 3 independent factors: cirrhosis (OR, 2.8; 95% CI: 1.6-12.8), other disease (OR, 2.7; 95% CI: 1.3-5.8), and preoperative urinary catheter (OR, 2.1; 95% CI: 1.1-4.6). A risk score for SSI was constructed: -4.9 + (1.5 x cirrhosis++) + (other disease++) + (0.8 x preoperative urinary catheter++) (++ = 0 if absent or 1 if present). The study included 1 group of patients having no risk factors for SSI with a score below -4.5 (S1R-) and 1 group of patients having 1 or more risk factors for SSI with a score over -4.5 (S1R+). Antibiotic prophylaxis did not reduce the infectious complication rate in the S1R- group, whereas, in the S1R+ group, it reduced significantly the rate of SSI and of parietal infectious complications by 58% and 69%, respectively.

CONCLUSIONS

Antibiotic prophylaxis in clean abdominal surgery was effective in high-risk patients. Urinary catheter must be avoided.

Prévalence et facteurs de risque de l’infection postopératoire en chirurgie orthopédique pédiatrique

PURPOSE OF THE STUDY

The incidence of postoperative infection in pediatric surgery has been studied little in the literature. It would be lower than in adults. In the present work, we attempted to define the incidence of postoperative infection in orthopedic pediatric surgery and identify risk factors.

MATERIAL AND METHODS

This was a retrospective analysis of 458 children who underwent surgery between 1998 and 1999 for the following conditions: talipes equinus, congenital hip dislocation, supracondylar fracture of the elbow, and femur shaft fracture. We noted the prevalence of infection of the surgical site, the type of infection and its course as well as the principal risk factors incriminated: age, condition, surgical modalities (emergency setting, hour, bleeding) and use of antibiotic prophylaxis.

RESULTS

Mean age at surgery was 5.4+/-3.5 years. The sex ratio was 1.6 boys/1 girl. Forty-two patients developed an infection of the surgical site, giving an incidence of 9.2% of the patients and 8.3% of the surgical sites. Postoperative infection was more frequent in the talipes equinus group (19.4% versus 5.8% for supracondylar fractures of the elbow, 2% for femur shaft fractures, and 0% for congenital hip displacement). In 78.6% of the cases, the infection was superficial. The analysis of risk factors showed that talipes equinus is an independent risk factor. The absence of antibiotic prophylaxis increased the risk of infection of the surgical site significantly only in the talipes equinus group (40.7% versus 14%).

DISCUSSION

The incidence of infection of the surgical site in pediatric orthopedic surgery was high in our series, 8.3% versus 0.4% and 5.6% reported in the literature. Talipes equinus surgery exposes the child to a significant risk of infection. The principal risk factors related to surgery would be: ischemia, inflammation of cutaneous and subcutaneous tissue due to detachment, the tourniquet, and the absence of antibiotic prophylaxis.

Prophylaxis of sternal wound infections with gentamicin-collagen implant: randomized controlled study in cardiac surgery

Postoperative infections may lead to prolonged hospital stay and increased morbidity, mortality and hospital costs, especially in heart surgery. Finding new means to prevent infections would benefit both the patient and society. The aim of this study was to assess if locally administered gentamicin prevents sternal wound infections in coronary artery bypass (CABG) surgery. We randomized 542 consecutive CABG patients to two groups: those who received gentamicin-collagen implant under their sternum before closure (N=272) and controls (N=270). The subjects received routine intravenous antimicrobial prophylaxis (85% cefuroxime, 14% cefuroxime and vancomycin), and were followed-up for three months. The sternal wound infection rate was 4.0% (11/272) in the gentamicin group and 5.9% (16/270) in the control group. The mediastinitis rates were 1.1 and 1.9%, respectively. This treatment was safe and easy to administer, and no side-effects occurred. No statistically significant difference was demonstrated between infection rates in the two groups. This is the first study on the use of gentamicin-collagen sponge as prophylaxis in cardiac surgery. Our data show that infection was reduced slightly in the gentamicin-collagen group compared with the control group, but the study population was too small to draw conclusions. Further evaluation is needed, and the results may warrant another larger, better-powered study.

Risk factors for surgical site infections in a free-standing outpatient setting

BACKGROUND

More information about risk factors for surgical site infections in outpatient settings is necessary for creation of surveillance systems in this field.

OBJECTIVE

The aim of this study was to determine the incidence of surgical site infections (SSI) in an outpatient setting and to investigate whether the risk index of the National Nosocomial Infections Surveillance (NNIS) System is appropriate for outpatient settings.

METHODS

A retrospective cohort design was used to investigate SSI following all hernia repairs and varicose veins operations over a 9-year period in a freestanding outpatient setting. The exposure variables studied were age, sex, and American Society of Anesthesiologists (ASA) score of the patient; duration of operation; performing surgeon's name; type of operation; type of anesthesia; and follow-up period. An univariable and a multivariable analysis were performed to determine risk factors for SSI.

RESULTS

A total of 1095 operations were performed: 714 on varicose veins and 381 on hernia repairs. The median follow-up period was 43 days. The crude SSI rate was 1.2% (varicose veins operations, 1.5%; hernia repair operations, 0.5%). According to the results of the logistic regression model, only 1 factor remained significant: Patients with spinal anesthesia were 11 times as likely to develop a SSI as patients with any other type of anesthesia (95% CI, 2.15-200.5).

CONCLUSION

The NNIS risk index was not suitable for assessing SSI rates in this outpatient setting and for these specific procedures.

Multivariate analysis of risk factors for deep and superficial sternal infection after coronary artery bypass grafting at a tertiary care medical center

Identification of modifiable risk factors for sternal infection is essential for the development and institution of practices that decrease the incidence of these infections. This study analyzed 4004 consecutive patients undergoing coronary artery bypass grafting performed at a single institution between January 1996 and May 2003. Specific risk factors for both superficial and deep sternal wound infection were identified by univariate and multivariate analysis. The incidence of superficial sternal wound infections was 2.2% (N = 87) while the incidence of deep sternal wound infections was 1.8% (N = 73). Risk factors for superficial sternal infection identified by multivariate analysis include increasing body mass index (BMI) (OR 1.089, 95% CI 1.057-1.122, P < 0.001), female gender (OR 1.412, 1.108-1.717, P = 0.036), active smoking (OR 1.856, 1.079-3.193, P = 0.025), utilization of bilateral internal mammary arteries (OR 7.546, 3.175-17.935, P < 0.001), and transfusion of > or =4 units of packed red blood cells postoperatively (OR 2.009, 1.158-3.485, P = 0.013). Risk factors for deep sternal infection include increasing BMI (OR 1.077, 1.042-1.114, P < 0.001), diabetes mellitus (OR 2.412, 1.376-4.231, P = 0.002), and transfusion with > or =2 units of platelets postoperatively (OR 2.787, 1.279-6.071, P = 0.010). These data suggest that cessation of smoking, improved blood glucose management, preoperative weight loss, limitation of transfusions, and discriminate use of bilateral internal mammary arteries are all practices that may decrease the incidence of postoperative wound complications following coronary revascularization.

Bacteria of preoperative urinary tract infections contaminate the surgical fields and develop surgical site infections in urological operations

BACKGROUND

The risk factors for surgical site infection (SSI) following urological operations have not been clearly identified, although the presence of a preoperative urinary tract infection (UTI) is thought to be one risk factor. We studied potential risk factors to clarify when and how bacteria contaminate wounds and SSI develop.

METHODS

Objects of the present study were patients with SSI after open urological operations that were performed at the Department of Urology, Miyazaki Medical College Hospital, University of Miyazaki, Kiyotake, Miyazaki, Japan, during the period between June 1999 and December 2000. Endourological operations, operations on children and short operations of less than 2 h duration were excluded. Patients were screened for the presence of UTI before the operation and subcutaneous swabs for culture were collected at the end of the operation by brushing with a sterile cotton-swab just before skin closure.

RESULTS

Surgical site infections occurred in 20 of 134 patients. Bacteria from the subcutaneous swabs were detected in 15 (75.0%) of the patients with SSI. All patients received antimicrobial prophylaxis (AMP), but bacteria from the subcutaneous swabs of patients with SSI were less susceptible to the agents (20.0%). Preoperative UTI were observed in 11 (55.0%) of the patients with SSI. In these patients, four had the same species of bacteria detected from urine, swab and wound, three had the same species from swab and wound and one had the same species from urine and wound.

CONCLUSIONS

Preoperative UTI was the most important risk factor for SSI following urological operations. It is most likely that the bacteria in the urine contaminated the surgical fields and the AMP resistant strains produced SSI.

Infections de site opératoire chez les patientes césarisées : bilan de 5 années de surveillance

AIMS

To determine the incidence of surgical site infections and to identify risk factors for infections.

METHOD

A prospective study of surgical site infections (SSI) after cesarean section was carried out from September 1997 to September 1998 (pilot study) and from January 2000 to August 2003, using the methodology of the American National Nosocomial Infection Surveillance System. Follow up of women was performed by midwives until discharge and during the post-natal visit. Suspected surgical site infections were confirmed by surgeons and infection control practitioners. The microbiological file of each patient was edited 30 days after cesarean section. Risk factors were analyzed using a logistic regression model.

RESULTS

During the pilot study, infection rate was estimated at 3.2%. At multivariate analysis, factors independently associated with an increased risk of SSI were ASA score > 1, performance of cesarean section in a room not dedicated to this activity, and use of an open urine drainage system. During the following years (2000-2003), infection rates progressively decreased to reach 1.9% in 2003. Infections included superficial wound infections (involving skin and subcutaneous tissue) (47%), deep wound infections (involving deep and soft tissue (fascia and muscle) (20%) and organ/space infections (i.e. endometritis, pelvic abscess) (33%). Infections occurred after patient discharge in 47.5% of cases and diagnosis was based only on clinical findings in 30% of cases. Infected patients were hospitalized longer (median: 6 days) than non infected patients.

CONCLUSION

Prospective surveillance of SSI led to better awareness of infectious problems among health care workers, to identification of risk factors and evaluation of health procedures. Surveillance contributed to a decrease in nosocomial infections.

Seguridad y eficacia del hierro intravenoso en la anemia aguda por fractura trocantérea de cadera en el anciano

BACKGROUND AND OBJECTIVE

An important percentage of patients with hip fracture need allogeneic transfusion to resolve their perioperative anemia. Our goal was to determine the safety profile and usefulness of parenteral iron in order to avoid allogeneic transfusions in trochanteric hip fracture (THF).

PATIENTS AND METHOD

A pseudo-experimental study was performed comparing a historic THF group (n = 104) with another group (n = 23) treated with parenteral iron (Venofer) (doses of 100 mg). Patients who had primary blood diseases or were receiving anticoagulation therapy were excluded. Age, gender, elapsed time, type of THF (international AO classification), surgical procedure, transfusion procedure and quantity, hemoglobin and hematocrit at days 0 and +2 (if a surgical procedure was not performed) and postoperatively were examined. We also analyzed the morbidity (post-surgical infection) and hospital stay and mortality rate at the first month.

RESULTS

We have not observed any adverse reactions upon iron administration. The iron group was transfused less times (39.1% vs. 56.7%) and had lower morbidity (infection) (20.3% vs. 35.4%) (p = 0.04), lower mortality (13% vs. 16.3%), less blood consumption (0.87 vs. 1.31 units) and less stay (13.7 vs. 14.3 days).

CONCLUSIONS

Parenteral administration of iron could be a safe and effective way to avoid or reduce allogeneic blood transfusions in THF patients. The reduction in the transfusional rate in the iron treated group is also accompanied by a reduction in the morbidity, infection rate, mortality rate and hospital stay.

Evolution of closed urinary drainage systems use and associated factors in Spanish hospitals

Although closed urinary drainage systems (CUDS) reduce the risk of catheter-associated urinary tract infection (CAUTI), open systems are still used in Spain. The object of this work was to describe the progress of CUDS use and factors associated with the drainage system type used in Spanish hospitals. The databases of the EPINE study (Study of Prevalence of Nosocomial Infections in Spain) from 1990 to 2000 were used. The EPINE study includes hospitalized patients of all ages in acute-care Spanish hospitals. Seventy-six thousand, seven hundred and eighty-eight catheterized patients were studied, and the whole database was used for the trend analysis of global hospital-acquired infection (HAI). The patient and the hospital were the two units of observation used in the analysis. Full implementation was defined as 90% CUDS use. A logistic regression model was applied to study factors influencing the use of CUDS and to determine prevalence trend. An odds ratio (OR) >1 indicates an incremental trend. The Pearson correlation coefficient between annual percentage of CUDS use and CAUTI prevalence was calculated. Variables for the year 2000 were compared using the Mann-Whitney U test between hospitals with and without full implementation. The prevalence of urinary catheterized patients in Spain increased from 12.4% in 1990 to 15.2% in 2000 (OR 1.019, 95% CI 1.016-1.021). The proportion of CUDS used increased from 50.6% in 1990 to 70% in 2000 (OR 1.1, 95% CI 1.095-1.104) and correlated with a significant decrease of UTIs (r = 0.65, P = 0.03). In 1990, 28.5% of hospitals had full implementation of CUDS and by 2000 this had risen to 40.3% (OR 1.093, 95% CI 1.06-1.127). Patients in medium (200-500 beds) and large (>500 beds) hospitals, as well as those with three of more diagnoses and two or more intrinsic risk factors had an increased probability of having a CUDS, whereas being hospitalized in areas other than intensive care, being male and less than 65 years old were associated with a lower probability of CUDS use. The median prevalence of catheterized patients in hospitals with full implementation, was significantly lower than in those without it (P = 0.049). Although CUDS use is increasing, there is still much work required to reach full implementation. Keeping CUDS for more severely ill patients may reflect a higher concern over the consequences of UTI in these patients. Nevertheless, it is necessary to change a practice that exposes patients to a known UTI risk factor and reach a consensus on indications for catheter insertion.

Can hospital discharge diagnoses be used for surveillance of surgical-site infections?

The aim of this study was to assess the data quality of postoperative infections in a hospital discharge registry in the Emilia-Romagna region of Italy. Data from a prospective regional study of postoperative infections in 6158 patients from 31 of the 36 public hospitals of the region were compared with data from the regional hospital discharge registry, using different classes of ICD-9-CM codes. The sensitivity of the hospital discharge database for postoperative surgical infections was 10% when ICD-9-CM codes directly indicative of postoperative infectious complications were used. When non-specific codes of postoperative complications, not necessarily of infectious origin, were added, the sensitivity reached 21%. At present, the hospital discharge registry is not suited for surveillance of hospital-acquired infection.

Clostridium infections associated with musculoskeletal-tissue allografts

BACKGROUND

Allografts are commonly used in orthopedic reconstructive surgery. In 2001, approximately 875,000 musculoskeletal allografts were distributed by U.S. tissue banks. After the death from Clostridium sordellii sepsis of a 23-year-old man who had received a contaminated allograft from a tissue bank (Tissue Bank A), the Centers for Disease Control and Prevention initiated an investigation, including enhanced case finding, of the methods used for the recovery, processing, and testing of tissue.

METHODS

A case of allograft-associated clostridium infection was defined as a culture-proven infection of a surgical site within one year after allograft implantation, from January 1998 to March 2002. We traced tissues to tissue banks that recovered and processed these tissues. We also estimated the rates of and risk ratios for clostridium infections for tissues processed by the implicated tissue bank and reviewed processing and testing methods used by various tissue banks.

RESULTS

Fourteen patients were identified, all of whom had received allografts processed by Tissue Bank A. The rates of clostridium infection were 0.12 percent among patients who received sports-medicine tissues (i.e., tendons, femoral condyles, menisci) from Tissue Bank A and 0.36 percent among those who received femoral condyles in particular. The risk-ratio estimates for clostridium infections from tissues processed by Tissue Bank A, as compared with those from other tissue banks, were infinite (P<0.001) for musculoskeletal allografts, sports-medicine tissues, or tendons. Because Tissue Bank A cultured tissues only after treating them with a nonsporicidal antimicrobial solution, some test results were probably false negatives. Tissues from implicated donors were released despite the isolation of clostridium or bowel flora from other anatomical sites or reports of infections in other recipients.

CONCLUSIONS

Clostridium infections were traced to allograft implantation. We provide interim recommendations to enhance tissue-transplantation safety. Tissue banks should validate processes and culture methods. Sterilization methods that do not adversely affect the functioning of transplanted tissue are needed to prevent allograft-related infections.

Hospital-acquired infections in Italy: a region wide prevalence study

Between October and December 2000, a region-wide prevalence study of hospital-acquired infections (HAI) was conducted in all public hospitals (59 facilities with ca. 16000 beds; 560000 admission yearly) in Piemonte Region, Italy, and in the one hospital of the neighbouring autonomous region of Valle d'Aosta. The study population comprised a total of 9467 patients hospitalized for at least 24 h. The prevalence of HAI was 7.84%, with marked differences in prevalence among the participating hospitals (range: 0-47.8%). The higher relative frequency of urinary tract infections (UTI; 52.7%) was due to the inclusion of urine cultures obtained on the day of the study from asymptomatic UTI in catheterized patients. A significant correlation was found with major risk factors related to medical procedures (urinary catheter, mechanical ventilation, surgical drainage, intravascular catheters). Patients with HAI were found to be older and to have a greater mean length of stay in hospital. Multiple logistic regression analyses showed that lack of independence, indwelling urinary catheter and mechanical ventilation were the risk factors more significantly associated with HAI. The use of antibiotics, in particular prophylactic agents used in surgery (cephalosporins, glycopeptides), provided an incentive for corrective intervention in antibiotic administration and in training of healthcare workers.

Perioperative Blood Transfusion Is Predictive of Poststernotomy Surgical Site Infection: Marker for Morbidity or True Immunosuppressant?

To analyze risk factors for the development of adult poststernotomy surgical site infections (SSIs), we performed a retrospective case-control study at a tertiary care hospital. Case patients with poststernotomy SSI between June 1999 and January 2001 were matched to control subjects without poststernotomy SSI according to date of procedure and age. Data were collected on known SSI risk factors. Of 711 procedures, we identified 38 cases with SSI and 114 matched controls. Univariate analysis revealed that receipt of transfused blood (odds ratio [OR], 3.19; 95% confidence interval [CI], 1.54-6.62), diabetes (OR, 2.90; 95% CI, 1.27-6.59), length of stay before hospitalization (OR, 1.19 per day; 95% CI, 1.02-1.37 per day), and American Society of Anesthesia score (OR, 2.19; 95% CI, 1.04-4.64) were significantly associated with SSI. Multivariate analysis revealed that transfusion (OR, 3.21; 95% CI, 1.41-7.31) and diabetes (OR, 3.65; 95% CI, 1.42-9.36) were predictors for SSI. The exact role of blood transfusion in the pathogenesis of SSI, whether as a direct immunosuppressant or a surrogate marker for morbidity, remains unresolved.

Risk factors for postoperative mediastinitis due to methicillin-resistant Staphylococcus aureus

Risk factors for developing postoperative mediastinitis (POM) due to methicillin-resistant Staphylococcus aureus (MRSA) were analyzed in a case-case control study of patients who underwent median sternotomy during the period from 1994 through 2000. Three patient groups were studied. The first consisted of 64 patients with POM due to MRSA; the second consisted of 79 patients with POM due to methicillin-susceptible S. aureus (MSSA); and the third consisted of 80 uninfected control patients. In multivariable analysis, patients who were diabetic (adjusted OR, 2.86; 95% CI, 1.22-6.70), female (OR, 2.70; 95% CI, 1.25-5.88), and >70 years old (OR, 3.43; 95% CI, 1.53-7.71) were more likely to develop POM due to MRSA. In contrast, the only independent risk factor associated with POM due to MSSA was obesity (OR, 2.49; 95% CI, 1.25-4.96). Antimicrobial prophylaxis consisted primarily of cephalosporin antibiotics (administered to 97% of the patients). Changes in perioperative antimicrobial prophylaxis, in addition to other interventions, should be considered for prevention of POM due to MRSA in targeted, high-risk populations.

Prophylaxis with cefazolin plus clindamycin in clean-contaminated maxillofacial surgery

PURPOSE

Infections after maxillofacial surgery are usually due to aerobic and anaerobic gram-positive cocci and gram-negative bacilli. Various antimicrobials, including cephalosporins, beta-lactams/beta-lactamase inhibitors, aminoglycosides, lincosamides, and fluoroquinolones, have been tested for use for perioperative prophylaxis in maxillofacial surgery. However, the best regimen has not been determined. We tested the safety and the efficacy of clindamycin plus cefazolin as perioperative prophylaxis for patients undergoing major maxillofacial procedures.

PATIENTS AND METHODS

Intravenous cefazolin and clindamycin in 3 doses were administered to 155 patients undergoing major maxillofacial procedures. After surgery, patients were monitored for the presence of infection and side effects.

RESULTS

No patient experienced a fever or infection after surgery. No side effects related to these antibiotics were observed.

CONCLUSIONS

The antibiotics used as prophylaxis in maxillofacial surgery should possess an adequate coverage against gram-positive aerobic and anaerobic cocci as well as gram-negative bacilli. Prophylaxis with cefazolin plus clindamycin in major maxillofacial seems safe and effective.

[Observational study investigating the use of levofloxacin in ICU patients]

INTRODUCTION

There is little information on the use of levofloxacin, a new quinolone, in ICU patients.

OBJECTIVE

To investigate the criteria for the use of levofloxacin (indications, forms of prescription, doses, and routes of administration) and to study tolerance in patients admitted to the ICU. Method. Prospective, observational study performed from October 2000 to November 2001 in 35 ICUs and including the first 15 patients receiving levofloxacin as monotherapy or combined treatment. Descriptive data are expressed as mean and percentage. Statistical significance was set at P < .05.

RESULTS

A total of 543 indications for treatment with levofloxacin were analyzed. The patients were 70.7% men, with a mean (SD) age of 60.2 (16.7) years, mean APACHE II score of 18.9 (7.9), and a medical underlying disease in 79.2% of cases. The ICU mortality rate was 24.1%. A total of 60% of patients required mechanical ventilation and 44.3% needed inotropic drug treatment. Levofloxacin was predominantly prescribed for treating community-acquired infections (67.8%), mainly in the respiratory tract (88.1%). An etiological diagnosis was established in only 55.6% of cases. The most common pathogens were Streptococcus pneumoniae (12.7%), Haemophilus influenzae (9.1%), Escherichia coli (7.4%), methicillin-sensitive Staphylococcus aureus (7.2%), Pseudomonas aeruginosa (4.9%), and Legionella pneumophila (4.7%). In 87.1% of indications, levofloxacin was prescribed as empirical treatment. Susceptibility of the isolated pathogens to this antibiotic was confirmed in 32.2% of cases. The initial dose was 500 mg/24 h in 48.5% of indications and 500 mg/12 h in 48.3%. Combined treatment was given in 49.7% of cases. In 32.2% of cases, parenteral administration of levofloxacin was changed to oral route. Adverse events probably or possibly associated with levofloxacin occurred in only 12.5% of patients and mainly included increased ALT/ALS levels (4.4%), diarrhea (2.3%), and heart rhythm alterations (2.1%).

CONCLUSIONS

This study describes the profile of critically ill patients receiving levofloxacin and the different forms of its use in the ICU.

Intraoperative antibiotic prophylaxis in clean spinal surgery: a retrospective analysis in a consecutive series of 973 cases

BACKGROUND

Antibiotic prophylaxis in spine surgery is still a debated question, involving medical, ethical, economic, and legal issues. The aim of our retrospective study was to evaluate the safety and effectiveness of an intraoperative protocol of antibiotic prophylaxis.

METHODS

During a 3-year period, 973 patients were consecutively operated on for clean spinal operations. Twenty-three percent of the cases involved the cervical spine and 77% the thoraco-lumbar spine; about 90% of patients were operated on for degenerative diseases and the remaining for traumatic lesions or tumors. Patients undergoing operations shorter than 120 minutes received a single-dose of IV ampicillin 1000 mg and sulbactam 500 mg (AS) at induction of anesthesia. In procedures longer than 120 minutes and/or requiring prosthetic materials, an IV single-dose of teicoplanin 400 mg was also administered at the same time. A second intraoperative dose of AS and teicoplanin was administered in operations longer than 4 hours (240 minutes after the first one) and in procedures in which blood loss exceeded 1500 mL. Postoperative prophylaxis has never been performed.

RESULTS

The only side effect was a cutaneous rash in 7 cases (0.7%), without any consequence. A wound infection was detected in 9 cases (<1%), all successfully treated with surgical toilette and specific antibiotic treatment. A lumbar discitis was detected in 4 out of 657 microdiscectomies (0.6%).

CONCLUSIONS

Even if this study has the weakness of the retrospective character, our intraoperative antibiotic prophylaxis protocol proved to be safe and efficacious. We hope that these preliminary results will be confirmed by larger prospectic trials.

Utilidad de los índices compuestos de riesgo para predecir el desarrollo de infección quirúrgica en neurocirugía

BACKGROUND AND OBJECTIVE

The use of risk indexes, originally developed in the US for the assessment of SSI risk, is an useful instrument that must be analyzed according to each specific procedure. The addition of other possible SSI risk factors, like the use of perioperative antibiotic prophylaxis, could improve the predictive value of these indexes. The aim of this study was to determine the SSI incidence rate for craniotomy in patients admitted to the Neurosurgical Unit of the Hospital Clinic of Barcelona (Spain), to assess the use of standard NNIS and SENIC indexes, and to assess the possible effect of the addition of a new risk factor (adequate or inadequate use of perioperative antibiotic prophylaxis) to these indexes.

PATIENTS AND METHOD

Risk factors for SSI were assessed following common standard definitions and procedures (CDC-NNIS) over a three-year period (1999-2001). NNIS and SENIC risk indexes were calculated. The effect of the addition of a new variable, namely perioperative antibiotic prophylaxis adequate (0 points) or inappropriate/no prophylaxis (1 point) on these indexes (modified indexes NNISa and SENICa) was also assessed. Statistical analysis included both parametric and non-parametric standard tests.

RESULTS

The study included a total of 203 patients undergoing a craniotomy procedure (40% of all neurosurgical procedures). The overall SSI incidence rate was 6.8% (14 patients developed SSI). The cut-off point (75 percentile) for the duration of the procedure was 180 minutes instead of the commonly US reported 240 minutes. Patients who develop SSI had a trend towards having shorter operation times. For those patients in the lower risk groups, the SSI incidence rate was: NNIS (0, 1): 6.9%; SENIC (0, 1): 6.2%. If the modified indexes were used, the SSI incidence rate was: NNISa (0, 1): 4.2%; SENICa (0, 1): 4.9%. When NNIS and SENIC indexes, both standard and modified (NNISa and SENICa), were compared, no statistically significant differences between infected and non-infected patients were observed.

CONCLUSIONS

When applied to a health system other than the US, SENIC and NNIS indexes could be useful if adapted to each specific situation and procedure. The added value of a new risk factor (perioperative antibiotic prophylaxis) on standard NNIS and SENIC indexes shows a slight improvement in their prediction rate for SSI in patients undergoing craniotomy, mainly in those patients at lower risk for developing superficial SSI.

A prospective study of surgical site infections in a pediatric hospital in Mexico City

BACKGROUND

Pediatric surgical site infection (SSI) rates in the United States range from 2.5% to 4.4%. There is little data regarding their risk factors among children. We quantified SSI rates and identified risk factors of SSI in a tertiary care pediatric teaching hospital in Mexico City.

METHODS

All neurosurgical, cardiovascular, and general surgical patients who underwent operation between Aug 1, 1998, and Jan 31, 1999, were followed-up daily during hospitalization. On postoperative day 30, a full review of microbiology reports and medical records was performed. Univariate and multivariate analyses were done to identify risk factors.

RESULTS

Four hundred twenty-eight of 530 children completed follow-up. The overall SSI rate was 18.7%. Forty percent of SSI were superficial incisional, 21% were deep incisional, and 39% were organ/space infections. For clean, clean-contaminated, contaminated, and dirty procedures, SSI infection rates were 12.4%, 24.4%, 14.3%, and 32.4%, respectively. Open drains (OR = 2.3; 95% CI = 1.3-4.2; P <.005) and surgery that lasted 90 or more minutes (OR = 2.9; 95% CI = 1.6-5.1; P <.001) were associated with infection.

CONCLUSIONS

Our rates are greater than comparable reported data among children. Duration of surgery and use of open drains were associated with SSI.

Effect of intensive surveillance on cesarean-section wound infection rate in a Saudi Arabian hospital

Surveillance for surgical site infection (SSI) in cesarean-section (C-section) in our hospital, carried out between September 1998 and July 1999, identified areas of deficiency in aseptic techniques that have contributed to increased incisional surgical site infection rates (ISSI) rates. On the basis of these findings, we intensified the infection control presence in this area and increased the number of in-services to our staff, with attention to infection control practices. Our senior infection control staff carried out ongoing monitoring of the ISSI rates as well as careful observation of aseptic technique. The aim was to reduce the rates of C-section ISSI in our hospital. We used the Centers for Disease Control and Prevention definitions for infection and the National Nosocomial Infections Surveillance System (NNISS) risk index in measuring the ISSI rates in the 2 time periods. We compared the ISSI rates with those of our preintervention period in an attempt to evaluate our interventional measures. Eight hundred seventy-five (875) C-sections were performed at King Fahad National Guard Hospital between January and December 2000. The overall ISSI rate was 1.37%. The ISSI rate for the NNISS risk category 0 (zero) was 1.2% and for the NNISS risk category 1 was 4.1%. There was a 50% reduction in the overall ISSI rates from our preintervention period (P <.05). Even though there were no objective means by which we measured the effect of infection control presence on the asepsis practices, there were no other changes that could have attributed to this significant reduction in ISSI rates in our C-section population.

Assessment of a selective surveillance method for detecting nosocomial infections in patients in the intensive care department

BACKGROUND

The implementation of a time- and cost-effective system for the surveillance of the nosocomial infection (NI) is a challenge for infection control practitioners.

OBJECTIVES

The aim of this study was to assess the sensitivity and the time reduction using a selective surveillance method (SSM) for the detection of NIs in comparison with a reference surveillance method (RSM).

METHODS

During a 12-month period, surveillance was performed prospectively in 4 intensive care departments on a rotating basis. Using the RSM, NIs were identified by prospective chart reviews performed twice a week combined with weekly infectious disease ward rounds. In the SSM, surveillance was reduced to microbiologic data and participation in the weekly infectious disease ward rounds followed by selective chart review.

RESULTS

In all, 578 patients amounting to 3597 patient-days were included in the study. In total, 78 NIs among 56 patients were identified. The overall sensitivity of the SSM compared with the RSM was 93.6% (73 of 78 NIs). The sensitivity of the SSM for the most important device-associated NIs (pneumonia, bloodstream infections, and urinary tract infections) was 96.3% (52 of 54 NIs) and 87.5% (21 of 24 NIs) for other NIs. Time required using the SSM was 1.3 hours compared with 4.1 hours per 10 beds per week (P =.0001) with the RSM.

CONCLUSIONS

Within our setting, a SSM with restriction to microbiology reports and participation in the infectious disease ward rounds detected NIs with a high sensitivity and a remarkable time reduction.

Surgical wound infection surveillance in general surgery procedures at a teaching hospital in Pakistan

BACKGROUND

A surveillance system was established at the Aga Khan University Hospital in Karachi, Pakistan, to determine surgical wound infection (SWI) rates, trends, and risk factors; and to compare rates with those reported by the National Nosocomial Infection Surveillance (NNIS) system of the Centers for Disease Control and Prevention.

METHODS

Surveillance was performed from January 1997 to December 1999. Risk categorization was on the basis of the NNIS system. P <.05 was set for statistically significant difference between groups. Data were analyzed using the Epi-Info software (version 6.04, CDC, Atlanta, Ga).

RESULTS

Overall SWI rates for the NNIS risk categories 0, 1, 2, and 3 were 1.9%, 3.7%, 6.7%, and 5.1%, respectively. SWI rate in 0 risk category decreased from 3% in 1997 to 1.1% in 1999 (P =.06). Multivariate analysis showed that SWI rates were higher after mastectomy (odds ratio [OR] 4.28, 95% confidence interval [CI] 1.8-10), hernia repair (OR 3.28, 95% CI 1.6-6.7), gastrointestinal resection (OR 2.2, 95% CI 0.88-5.9), skin procedures (OR 1.97, 95% CI 0.89-4.3), appendectomy OR 0.57, 95% CI 0.20-1.60, and miscellaneous procedures (OR 3.6, 95% CI 1.6-7.7), as compared with cholecystectomy. Other risk factors were contaminated type of operation (OR 2.6, 95% CI 1.2-5.5), and duration of operation exceeding the NNIS standard of "T" hours (OR 2.6, 95% CI 1.7-4).

CONCLUSION

The SWI rates at the Aga Khan University Hospital are higher than the NNIS standards. There was a downward trend in the SWI rates during the surveillance period. A decrease in the duration of surgical procedures could further reduce the risk.

Diabetes and coronary artery bypass surgery: an examination of perioperative glycemic control and outcomes

OBJECTIVE

To determine the adequacy of perioperative glycemic control in diabetic patients undergoing coronary artery bypass grafting (CABG) and to explore the association between glycemic control and in-hospital morbidity/mortality.

RESEARCH DESIGN AND METHODS

Retrospective cohort study of consecutive patients with diabetes undergoing CABG between April 2000 and March 2001 who survived at least 24 h postoperatively.

RESULTS

Of the 291 patients in this study, 95% had type 2 diabetes and 40% had retinopathy, nephropathy, or neuropathy at baseline. During hospitalization (median 7 days), 78 (27%) of these patients suffered a nonfatal stroke or myocardial infarction, septic complication, or died ("adverse outcomes"). Glycemic control was suboptimal (average glucose on first postoperative day was 11.4 [11.2-11.6] mmol/l) and was significantly associated with adverse outcomes post-CABG (P = 0.03). Patients whose average glucose level was in the highest quartile on postoperative day 1 had higher risk of adverse outcomes after the first postoperative day than those with glucose in the lowest quartile (odds ratio 2.5 [1.1-5.3]). Even after adjustment for other clinical and operative factors, average blood glucose level on the first postoperative day remained significantly associated with subsequent adverse outcomes: for each 1-mmol/l increase above 6.1 mmol/l, risk increased by 17%.

CONCLUSIONS

Perioperative glycemic control in our cohort of diabetic patients undergoing CABG in a tertiary care facility was suboptimal. We believe closure of this care gap is imperative, because hyperglycemia in the first postoperative day was associated with subsequent adverse outcomes in our study patients.

Does using a laparoscopic approach to cholecystectomy decrease the risk of surgical site infection?

OBJECTIVE

To assess the impact of laparoscopy on surgical site infections (SSIs) following cholecystectomy in a large population of patients.

SUMMARY BACKGROUND DATA

Previous investigations have demonstrated that laparoscopic cholecystectomy is associated with a shorter postoperative stay and fewer overall complications. Less is known about the impact of laparoscopy on the risk for SSIs.

METHODS

Epidemiologic analysis was performed on data collected during a 7-year period (1992-1999) by participating hospitals in the National Nosocomial Infections Surveillance (NNIS) System in the United States.

RESULTS

For 54,504 inpatient cholecystectomy procedures reported, use of the laparoscopic technique increased from 59% in 1992 to 79% in 1999. The overall rate of SSI was significantly lower for laparoscopic cholecystectomy than for open cholecystectomy. Overall, infecting organisms were similar for both approaches. Even after controlling for other significant factors, the risk for SSI was lower in patients undergoing the laparoscopic technique than the open technique.

CONCLUSIONS

Laparoscopic cholecystectomy is associated with a lower risk for SSI than open cholecystectomy, even after adjusting for other risk factors. For interhospital comparisons, SSI rates following cholecystectomy should be stratified by the type of technique.

The clinical relevance of microbiology in acute and chronic wounds

PURPOSE

To improve clinical practice and the quality of patient care by providing a learning opportunity that enhances the participant's understanding of how wound microbiology affects healing.

TARGET AUDIENCE

This CME/CE activity is intended for physicians and nurses with an interest in interpreting the role of microorganisms in wound healing.

OBJECTIVES

At the conclusion of this course, participants should be able to: 1. Identify the microbiology of acute and chronic wounds, risk factors for infection, and advantages and disadvantages of wound culturing. 2. Identify methods of debridement and wounds for which they are appropriate. 3. Identify systemic antibiotic treatment options for acute and chronic wound infections.

A user evaluation of the Nosocomial Infection National Surveillance System: surgical site infection module

The Nosocomial Infection National Surveillance Scheme (NINSS) enables hospitals in England to undertake surveillance of healthcare associated infection, compare their results with national aggregated data, and use the information to improve patient care. A surgical site infection (SSI) module was introduced in 1997, and participation has increased steadily since its inception. This survey was undertaken to assess the views of users on the current service, and how the module should be developed to best meet their needs and resources. Survey forms were sent to infection control teams (ICTs) at the 113 hospitals that had participated at any time during the first three years of the programme. The response rate was 90% (102). The views of users were generally very positive and indicated considerable support for the approach to this type of surveillance. The ability to compare hospital infection rates with national data, the availability of standardized surveillance methods, and centralized data analysis and report production were key reasons for participation for over 80% of users. Most did not wish to see any major changes made to the protocol, although more than a third of users suggested additional data items. Overall, users were satisfied with both the content and timescale for receipt of feedback reports, and 77% disseminated them to at least three groups of clinicians and managers. The majority of ICTs (89%) gave the results directly to the surgeons. For some users (29%) it was too early to assess the value of the surveillance. Of the remainder, although results provided evidence of good performance for some, 46% identified high rates of SSI in one or more groups of surgical patients. In about two-thirds of these hospitals, a review or change in clinical practice was initiated as a result. Three main areas for development were identified: an extended range of surgical procedures, post-discharge surveillance and improved local data collection and analysis systems. Users said they would also like training in handling and interpreting surveillance data. These needs should be addressed in order to ensure the continuing success of national surveillance.

Relationship between hospital infection and long-term mortality in general surgery: a prospective follow-up study

A prospective study of 1431 patients admitted to a general surgery department were followed up for a median of 6.2 years after discharge (7679 person-years of follow-up). We collected information on underlying conditions, including severity of illness, and healthcare-related variables. Relative rates of death and their 95% confidence interval (CI) were estimated using person-years as the denominator. Multiple-risk factors adjusted for relative rates (RR) were obtained using Poisson regression analysis. There were 172 deaths during the follow-up period after hospital discharge (2/100 person-years). Follow-up was complete in 91% of the cohort. There were no important differences in demographic characteristics or risk factors between patients followed up and those lost to follow-up. The death rate in patients with any hospital-acquired infection was 5.3/100 person-years, and the relative rate was 3.07 (95% CI: 2.20-4.24). After adjusting for the main predictors of mortality, we found an effect modification by the presence of chronic disease (P = 0.01 for the product-term between hospital infection and the diagnosis of chronic diseases). Among patients without any underlying chronic disease, hospital-acquired infection was related to a significantly higher long-term mortality (RR = 2.47, 95% CI: 1.24-4.91). In these patients, surgical wound infection yielded a RR of mortality of 3.44 (95% CI: 1.63-7.27). Among patients with underlying chronic disease no association between hospital infection and long-term mortality was found. No evidence of an important modification of the relative rate along the follow-up period was observed. In conclusion surgical patients without chronic disease developing hospital-acquired infection have an increased risk of long-term mortality.

Surfactant protein D binds selectively to Klebsiella pneumoniae lipopolysaccharides containing mannose-rich O-antigens

Surfactant protein D (SP-D) plays important roles in the regulation of innate immune responses in the lung. We have previously shown that SP-D can agglutinate and enhance the macrophage-dependent killing of specific unencapsulated phase variants of Klebsiella pneumoniae. In the present studies, we used 16 clinical isolates of Klebsiella representing four O-serotypes and examined the interaction of SP-D with their isolated LPSs. Although SP-D bound to the core oligosaccharide of rough LPS from all isolates, it selectively bound to smooth forms of LPS expressed by O-serotypes with mannose-rich repeating units in their O-polysaccharides. SP-D was more potent in agglutinating unencapsulated phase variants of O-serotypes expressing these SP-D "reactive" O-polysaccharides, and more effectively inhibited the adhesion of these serotypes to lung epithelial cells. This novel anti-adhesion activity required the multimerization of trimeric SP-D subunits (dodecamers). Klebsiella serotypes expressing "nonreactive" LPS O-Ags were isolated at a significantly higher frequency from patients with K. pneumoniae. Our findings suggest that SP-D plays important roles in the clearance of opportunistic Gram-negative bacteria and contributes to known serotypic differences in the pathogenicity of Klebsiella through specific interactions with O-polysaccharides.

Awareness of surgical site infections for advanced practice nurses

A primary concern in healthcare today is the prevention of infection. Surgical site infections (SSIs) are the leading type of infection among hospitalized patients. Advanced practice nurses play a vital role in patient care, and those who incorporate best practice standards can reduce the morbidity and mortality associated with SSIs. The Centers for Disease Control and Prevention have published recommendations for prevention of SSIs. This article reviews current literature regarding the prevention of SSIs and how critical care practitioners can incorporate these scientifically tested recommendations into their practice.

[Etiology of hospital-acquired infections in Spanish hospitals (EPINE, 1990-1999)]

BACKGROUND

Clinical and demographic characteristics of patients, their interaction with pathogens and antimicrobial therapies are prompting changes in the epidemiology of hospital-acquired infections (HI). The knowledge of the etiology of hospital-acquired infections is valuable for the treatment of infected patients and for the prevention of HI.

PATIENTS AND METHOD

We analyzed a series of 10 annual prevalence studies during the period 1990-1999 (EPINE project) in Spanish hospitals. Estimate of prevalence of infection was calculated by means of the percent distribution of every organism regarding overall identified organisms and infections.

RESULTS

40,550 HI were identified among 484,013 patients (HI prevalence = 8.4%; 95% CI, 8.3-8.5%). Gram-positive organism predominated steadily in bloodstream and surgical wound infections, while gram-negative bacilli predominated in respiratory and urinary tract infections. There was an increase in HI infections by Acinetobacter baumannii (from 1.9% in 1990 to 3.6% in 1999; P < 0.001) and Candida albicans (from 2.4 to 3.2%; P < 0.001), as well as an increase in both HI and community-acquired infections by methicillin-resistant Staphylococcus aureus [HI: from 4.7 to 40.2% (P < 0.001); community-acquired: from 2.7 to 15.6% (P < 0.001)].

CONCLUSIONS

We observed some changes in the etiology of infections over the last decade: rates of methicillin-resistant S. aureus hospital-acquired and community-acquired infections increased steadily and their initial rates multiplied by 8 and 6, respectively. Rates of HI caused by yeasts and A. baumannii increased also.

Decision support for infectious diseases--a working prototype

This paper presents a decision support system for nosocomial infections and its integration in the large HIS of the University Hospital of Giessen. The system comprises five different engines and a data dictionary. It is designed to detect hospital acquired infections even in a situation where only a restricted amount of clinical data is available (the data is split up in different information systems). Furthermore the model prevents time consuming manual data entry. The five engines split the main task into: (1) a preselection, which sorts out patients who definitely do not have a nosocomial infection; (2) a rule based reasoning process which detects patients likely to have such an infection; (3) an alarm process which is responsible for the presentation of the alert; (4) an explanation process to follow up the reasoning; and (5) statistic tools to answer specific hygienic questions. A data dictionary supplies the controlled vocabulary, which is required to understand data structures used in the different clinical subsystems and may those with each other.

The effect of surgical site infections on outcomes and resource utilization after liver transplantation

BACKGROUND

Although postoperative infections have a significant impact on morbidity and mortality after orthotopic liver transplantation (OLT), less is known about their economic implications. In this study, we sought to identify risk factors and estimate the impact of surgical site infections on 1-year mortality, graft survival, and resource utilization after OLT.

METHODS

We studied 777 first, single-organ liver transplant recipients from the National Institute of Diabetes and Digestive and Kidney Diseases Liver Transplantation Database. Surgical site infections (n = 292, 37.8%) were defined as bacterial or fungal infections of the liver, intestine, biliary tract, surgical wound, or peritoneum within 1 year of transplantation. A subset of these (n = 159) occurred during the transplant hospitalization and were used to estimate excess charges associated with surgical site infections.

RESULTS

Leaks in the choledochojejunostomy (odds ratio [OR] = 7.1, P =.001) and choledochocholedochostomy (OR = 2.5, P =.002), extended operation duration in hours (OR = 1.2, P =.002), serum albumin levels in grams per liters (OR = 0.71, P =.009), ascites (OR = 1.43, P =.037), and administration of OKT3 within 7 days (OR = 1.49, P =.039) significantly increased risk of infection. Surgical site infections did not significantly increase 1-year mortality (88.5% vs 91.5%, P =.19) but significantly increased 1-year graft loss (79.8% vs 86.5%, P =.022). Patients with surgical site infections incurred approximately 24 extra hospital days and $159,967 in excess charges (P =.0001). Multivariate analysis reduced the estimate of excess charges to $131,276 (P =.0001).

CONCLUSIONS

Liver transplant recipients who develop surgical site infection have significantly higher resource utilization requirements than those who do not. These results imply substantial returns to preventative efforts directed at surgical site infections in patients undergoing OLT.

A retrospective review of 228 episodes of infective endocarditis where rheumatic valvular disease is still common

Two hundred and twenty-eight episodes of infective endocarditis in adult patients (mean age 36 years) were reviewed retrospectively. There were 183 episodes (80%) of native valve, 15 (7%) early prosthetic valve and 30 (13%) late prosthetic valve endocarditis. The most common predisposing factor was rheumatic valvular disease (65%). None of the patients were intravenous drug users. According to the Duke criteria, the number of definite, probable and rejected episodes were 121 (53%), 94 (41%) and 13 (6%), respectively. Additional minor criteria increased the number of definite endocarditis to 82%. The Duke criteria are not primarily intended to influence treatment decisions but are helpful in standardising research activities. The choice of the level of sensitivity or specificity of the criteria may be adjusted according to the aim of the study and prevalence of disease in a particular area. More sensitive criteria may be valuable in those countries where the prevalence of rheumatic valvular disease is still high.

Surgical site infections in ambulatory surgery: a 5-year experience

OBJECTIVES

To evaluate the ambulatory surgical site infection rate and risk factors associated with surgical site infection.

METHODS

We conducted a case-control analysis of all ambulatory surgeries between January 1, 1993, and December 31, 1997. The frequency of surgical site infection per 100 surgeries was calculated. The odds ratio (OR) was estimated by using logistic regression analysis.

SETTING

A 140-bed tertiary-care teaching hospital for adult patients with cancer.

RESULTS

The study followed 1350 outpatient surgeries. Thirty-eight patients had a surgical site infection (rate per 100 surgeries: 2.8). The risk factors statistically associated with surgical site infection were postoperative antibiotics (OR = 7.5; 95% CI, 2.5-23.0), and surgical time >35 minutes (OR = 2.4; 95% CI, 1.1-5.5).

CONCLUSIONS

The surgical site infection rate for same-day surgery at our hospital is within the limits reported in the literature and below the rates reported previously for inpatient surgeries at our hospital. Full review of medical records and microbiology reports at day 30 allowed us to identify infections that otherwise would have been missed. Postoperative antibiotics may increase the risk of infection.

Impact of antibiotic prophylaxis on wound infection after cesarean section in a situation of expected higher risk

BACKGROUND

To measure rates of incisional surgical site infection (ISSI) after cesarean section (CS) and to assess risks for infection.

METHODS

Prospective surveillance for ISSI at a 540-bed hospital in Saudi Arabia by using Centers for Disease Control and Prevention definitions for infection and the National Nosocomial Infections Surveillance (NNIS) system risk index.

RESULTS

Seven hundred thirty-five CSs were studied from September 1998 to July 1999; 72% were emergency procedures, despite a 95% rate of antenatal care. The overall ISSI rate was 2.8% (95% confidence interval [CI], 1.7%-4.3%). The rate for NNIS risk category 0 was 2.4% (95% CI, 1.3%-4.2%; n = 536) and for category 1 was 4.1% (95% CI, 1.8%-8.6%; n = 170). In the multivariate analysis, the only independent risks for ISSI were duration of surgery (OR = 1.01; 95% CI, 1.00-1.03; P =.02) and no antibiotic prophylaxis (OR = 3.09; 95% CI, 1.10-9.11; P =.04). Antibiotic prophylaxis was inconsistently administered among both emergency and elective CS. Infection control procedures were inadequate in the obstetric suite operating room.

CONCLUSIONS

Despite deficient infection control practices in the setting described, ISSI rates after CS were judged "acceptable" compared with NNIS benchmark rates. This was attributed to prescribing antibiotic prophylaxis for patients at low risk as well as high risk of infection.

Epidemiology of and surveillance for postpartum infections

We screened automated ambulatory medical records, hospital and emergency room claims, and pharmacy records of 2,826 health maintenance organization (HMO) members who gave birth over a 30-month period. Full-text ambulatory records were reviewed for the 30-day postpartum period to confirm infection status for a weighted sample of cases. The overall postpartum infection rate was 6.0%, with rates of 7.4% following cesarean section and 5.5% following vaginal delivery. Rehospitalization; cesarean delivery; antistaphylococcal antibiotics; diagnosis codes for mastitis, endometritis, and wound infection; and ambulatory blood or wound cultures were important predictors of infection. Use of automated information routinely collected by HMOs and insurers allows efficient identification of postpartum infections not detected by conventional surveillance.

Multicenter surveillance study for nosocomial infections in major hospitals in Korea. Nosocomial Infection Surveillance Committee of the Korean Society for Nosocomial Infection Control

BACKGROUND

The goals of a surveillance for nosocomial infections (NIs) are to observe the magnitude and characteristics of NIs and to plan and evaluate policies and guidelines of infection control. This study was designed to determine the rate and distribution of NIs and their causative pathogens in Korean hospitals.

METHODS

Prospective surveillance was performed at 15 acute care hospitals with more than 500 beds during a 3-month period from June to August 1996. The case-finding methods were laboratory-based surveillance for patients in the general wards and a direct review of medical charts done regularly for all the patients in the intensive care units.

RESULTS

A total of 3162 NIs were found among 85,547 discharged patients, with an overall nosocomial infection rate of 3.70 per 100 patients discharged. Urinary tract infections constituted 30.3% of all NIs. Other infections were pneumonias, 17.2%, surgical site infections, 15.5%, and primary bloodstream infections, 14.5%. The infection rate was the highest in neurosurgery (14.21), followed by neurology (8. 62) and ontology services (6.70). The infection rate in intensive care units was higher than it was in the general wards (10.74 vs 2. 57, P =.001). The commonly isolated organisms were Staphylococcus aureus (17.2%), Pseudomonas aeruginosa (13.8%), and Escherichia coli (12.3%).

CONCLUSIONS

This first multicenter surveillance study provided extensive information on the current status and trends of NIs in major hospitals in Korea. The results may contribute to the evaluation of infection control programs and the development of effective strategies in these hospitals.

Wound closure technique and acute wound complications in gastric surgery for morbid obesity: a prospective randomized trial

BACKGROUND

During the past 10 years, numerous clinical studies have supported the use of continuous monofilament fascial closure after laparotomy. Because of the increased incidence of surgical-site infections and other acute wound complications in the morbidly obese, these patients are well suited for a study of technical factors that may affect the frequency of these wound complications.

STUDY DESIGN

A prospective, randomized study of the midline fascial closure technique in gastric bariatric operations was conducted between 1991 and 1998 in 331 consecutive morbidly obese patients. At the time of closure of the upper midline laparotomy wound, the patients were randomized into two groups: Group I patients (n = 172) underwent continuous fascial closure and group II patients (n = 159) underwent interrupted fascial closure. All patients received prophylactic antibiotics in a similar fashion. Wounds were monitored for 30 days postoperatively, and acute wound complications were classified as superficial or deep. Superficial complications included superficial surgical-site infections, seromas, and hematomas. In all superficial complications, the fascia remained uninvolved and intact. Deep wound complications included deep surgical-site infections and fascial dehiscence.

RESULTS

A total of 49 acute wound complications occurred (15%). There were 22 superficial (7%) and 27 deep (8%) wound complications in the 331 in the patients studied. Group I patients experienced fewer total wound complications than group II patients (18 versus 31; p=0.021). Group I patients also experienced fewer deep wound complications than group II (5 versus 22; p = 0.003).

CONCLUSIONS

Continuous fascial closure reduces major acute wound complications in morbidly obese patients undergoing gastric operations for obesity.

Surgical site infections at the National Cancer Institute in Mexico: a case-control study

OBJECTIVES

To quantify the surgical infection rate and to identify risk factors associated with surgical site infection.

METHODS

We conducted a case-control study of all surgical patients between January 1, 1993, and June 30, 1994. The frequency of surgical site infection per 100 surgeries was calculated. The odds ratio (OR) was estimated by using logistic regression analysis.

SETTING

A 130-bed tertiary-care teaching hospital for adult patients with cancer.

RESULTS

The study followed 3372 surgeries. Three hundred thirteen patients had a surgical site infection (rate per 100 surgeries: 9. 30). The risk factors associated with surgical site infection were diabetes mellitus (OR = 2.5, 95% confidence interval [CI] = 1.27-4. 91), obesity (OR = 1.76, 95% CI = 1.14-2.7), presence of surgical drains for >5 and <16 days (OR = 1.84, 95% CI = 1.02-3.31), and presence of surgical drains for >/=16 days (OR = 2.14, 95% CI = 1. 0-4.6). The bacteria most frequently isolated were Escherichia coli 38 (21.8% of the total of microorganisms found), Pseudomonas sp 22 (12.6%), Staphylococcus aureus 16 (9.2%), and coagulase-negative Staphylococcus 25 (13.6%). The coexistence of other nosocomial infections was greater among the cases (OR = 1.8, 95% CI = 1.1-3.1) than in the control group.

CONCLUSIONS

The surgical site infection rate in our hospital is slightly higher than the rates reported for general hospitals. The risk factors associated with surgical site infection are similar to those previously reported. Diabetes mellitus, obesity, and prolonged presence of a surgical drain increased the risk of infection.

Quantifying excess length of postoperative stay attributable to infections: a comparison of methods

To quantify the net effect of deep surgical site infection (DSSI) on postoperative stay (POS) among patients who had undergone open heart surgery, and to assess the comparability of two methods, two observational studies were conducted: one on a retrospective cohort of 701 operated patients, and the other on a cohort of 31 infected patients versus a cohort of uninfected patients, with 1:1 matching. In addition to DSSI, a further three factors were identified by multivariate analysis as independent POS-related predictor variables. After internal validation of the multivariate model, excess POS attributable to DSSI amounted to 20.7 days (95% confidence interval [CI] 16.7-24.9). In contrast, excess length of stay attributable to DSSI among the matched pairs who survived infection (22) totaled 14.3 days (95% CI 3.2-25.4) and 26.5 days (mean and median differences). Multivariate techniques may prove a more appropriate and reliable analysis than matched-pair comparisons for the purpose of evaluating the extra stay and cost attributable to the nosocomial infections.