Preoperative risk prediction of surgical site infection requiring hospitalization or reoperation in patients undergoing vascular surgery.

OBJECTIVE: The objective of this study was to develop a surgical site infection (SSI) prediction score for risk assessment before elective vascular surgery. METHODS: We conducted a nested case-control study among patients who underwent elective vascular (abdominal aortic and peripheral arterial) surgery from January 1, 2003, to December 31, 2007, at Mayo Clinic (Rochester, Minn) an academic tertiary surgical center. Cases were patients with SSI requiring hospitalization; controls (one or two per case) were matched on type of procedure and date of surgery. Clinical data were collected by chart review. A risk score based on preoperative variables was developed using multivariable logistic regression and bootstrap resampling. The C statistic, equivalent to the area under the receiver operating characteristic curve, was used to assess discrimination. Calibration was assessed by plotting percentile risk groups of model-predicted values against observed proportions of subjects with SSI. RESULTS: Eighty-four cases were compared with 160 controls. Preoperative variables independently associated with SSI risk were critical limb ischemia, previous SSI, prior revascularization procedure, and chronic obstructive pulmonary disease. A prediction model containing these variables was developed (model and risk score C statistic of 0.737 and 0.727, respectively). The calibration curve did not appear to deviate appreciably from the 45-degree line of identity. CONCLUSIONS: We developed an SSI risk score based on noninvasive preoperative variables with acceptable discrimination and calibration. This tool needs prospective and external validation.

Assessment of prophylactic antibiotic use in patients with surgical site infections.

BACKGROUND: Surgical site infections (SSIs) are the leading cause of hospital-acquired infections and are associated with substantial health care costs, with increased morbidity and death. The Surgical Care Improvement Project (SCIP) contains standards that are nationally reported with the aim of improving patient outcomes after surgery. Our institution's standards for antimicrobial prophylaxis in the perioperative period are more stringent than these measures and may be considered "beyond SCIP." The 4 elements of appropriate antimicrobial prophylaxis are timing, antibiotic selection, dosing, and intraoperative redosing. OBJECTIVE: To quantify antimicrobial SSI prophylaxis compliance in accordance with institutional standards and to identify potential opportunities for improvement. METHODS: Patients aged 18 years or older were included if they had an SSI between January 1, 2009, and June 30, 2010, according to the database maintained prospectively by the Infection Prevention and Control Unit. Adherence to our institution's practice standards was assessed through analysis of antibiotics administered-timing in relation to the incision, closure, and tourniquet inflation times for the procedure and antibiotic selection, dose, and redosing. RESULTS: Overall noncompliance with all 4 elements of antimicrobial prophylaxis was 75.4% among the 760 cases. Repeat dosing had the greatest noncompliance (45.1%); antibiotic selection had the lowest incidence of noncompliance (10.8%). CONCLUSIONS: Noncompliance existed in each element of antimicrobial SSI prophylaxis, with antibiotic redosing leading in noncompliance. With the implementation of tools to assist the surgical team in following institutional standards, noncompliance will likely decline and additional research opportunities will exist.

What is preventable harm in healthcare? A systematic review of definitions.

BACKGROUND: Mitigating or reducing the risk of harm associated with the delivery of healthcare is a policy priority. While the risk of harm can be reduced in some instances (i.e. preventable), what constitutes preventable harm remains unclear. A standardized and clear definition of preventable harm is the first step towards safer and more efficient healthcare delivery system. We aimed to summarize the definitions of preventable harm and its conceptualization in healthcare. METHODS: We conducted a comprehensive electronic search of relevant databases from January 2001 to June 2011 for publications that reported a definition of preventable harm. Only English language publications were included. Definitions were coded for common concepts and themes. We included any study type, both original studies and reviews. Two reviewers screened the references for eligibility and 28% (127/460) were finally included. Data collected from studies included study type, description of the study population and setting, and data corresponding to the outcome of interest. Three reviewers extracted the data. The level of agreement between the reviewers was calculated. RESULTS: One hundred and twenty seven studies were eligible. The three most prevalent preventable harms in the included studies were: medication adverse events (33/127 studies, 26%), central line infections (7/127, 6%) and venous thromboembolism (5/127, 4%). Seven themes or definitions for preventable harm were encountered. The top three were: presence of an identifiable modifiable cause (58/132 definitions, 44%), reasonable adaptation to a process will prevent future recurrence (30/132, 23%), adherence to guidelines (22/132, 16%). Data on the validity or operational characteristic (e.g., accuracy, reproducibility) of definitions were limited. CONCLUSIONS: There is limited empirical evidence of the validity and reliability of the available definitions of preventable harm, such that no single one is supported by high quality evidence. The most common definition is "presence of an identifiable, modifiable cause of harm".

Extended antibiotic prophylaxis for prevention of surgical-site infections in morbidly obese women who undergo combined hysterectomy and medically indicated panniculectomy: a cohort study.

OBJECTIVE: The purpose of this study was to compare surgical-site infection rates in obese women who had extended prophylactic antibiotic (EPA) vs standard prophylactic antibiotic. STUDY DESIGN: An electronic records-linkage system identified 145 obese women (body mass index, >30 kg/m(2)) who underwent combined hysterectomy and panniculectomy from January 1, 2005, through December 31, 2008. The EPA cohort received standard antibiotics (cefazolin, 2 g) and continued oral antibiotic (ciprofloxacin) until removal of drains. Regression models were used to adjust for known confounders. RESULTS: The mean age was 56.0 + or - 12.1 years, and mean body mass index was 42.6 + or - 8.4 kg/m(2) (range, 30-86.4 kg/m(2)). The EPA cohort experienced fewer surgical-site infections (6 [5.9%] vs 12 [27.9%]; P < .001; adjusted odds ratio, 0.16; 95% confidence interval, 0.04-0.51; P < .001), had lower probability of incision and drainage (3 [2.9%] vs 5 [11.6%]; P = .05), and required fewer infection-related admissions (5 [4.9%] vs 6 [13.9%]; P = .08). CONCLUSION: Extended antibiotic prophylaxis can reduce surgical-site infections in obese women after combined hysterectomy and panniculectomy.

Incidence of infectious complications after an ultrasound-guided intervention.

OBJECTIVE: The objective of our study was to determine the incidence of infectious complications of common ultrasound-guided procedures including fine-needle aspiration (FNA), drain placement, biopsy, pseudoaneurysm thrombin injection, thoracentesis, and paracentesis. SUBJECTS AND METHODS: The infection prevention and control (IPAC) committee at the Mayo Clinic, Rochester, MN, conducts surveillance of selected infections including radiology procedures. When a positive culture, hospital admission, or operating room visit for infection is identified, the patient's electronic records are thoroughly reviewed by an infection control practitioner looking for information about prior interventions. Similarly, the department of radiology prospectively follows all patients who have undergone ultrasound-guided hepatic, renal, and pancreatic biopsies for complications 24 hours, 3 months, and 12 months after biopsy. We reviewed 2 years of these data to determine the incidence of infections after common ultrasound-guided procedures. RESULTS: We performed 13,534 ultrasound-guided procedures from January 2006 to December 2007. There were 11 likely and three possible procedure-related infections for an overall incidence of 0.1% (14/13,534). The infections consisted of five abscesses, four bloodstream infections, four cases of peritonitis, and one urinary tract infection. The highest incidence of infections occurred after ultrasound-guided biopsy (0.2%, 10/5,487), with biopsy of a hepatic transplant having the highest incidence (1.0%, 2/192). No infections occurred after thoracentesis and FNA despite the large number of procedures performed (2,489 and 2,340, respectively). Nearly all patients improved on antibiotics. One patient died 5 days after paracentesis; however, death was likely due to multiorgan failure in the setting of fulminant liver failure with hepatorenal syndrome. CONCLUSION: The incidence of a serious infectious complication after ultrasoundguided intervention is low. Radiologists can use these data to provide more accurate information to patients when asking for consent before procedures and to reassure their patients.

Duration of influenza A virus shedding in hospitalized patients and implications for infection control.

OBJECTIVE: To assess the duration of shedding of influenza A virus detected by polymerase chain reaction (PCR) and cell culture among patients hospitalized with influenza A virus infection. SETTING: Mayo Clinic (Rochester, Minnesota) hospitals that cater to both the community and referral populations. METHODS: Patients 18 years old and older who were hospitalized between December 1, 2004, and March 15, 2005, with a laboratory-confirmed (ie, PCR-based) diagnosis of influenza A virus infection were consecutively enrolled. Additional throat swab specimens were collected at 2, 3, 5, and 7 days after the initial specimen (if the patient was still hospitalized). All specimens were tested by PCR and culture (both conventional tube culture and shell vial assay). Information on demographic characteristics, date of symptom onset, comorbidities, immunosuppression, influenza vaccination status, and receipt of antiviral treatment was obtained by interview and medical record review. Patients were excluded if informed consent could not be obtained or if the date of symptom onset could not be ascertained. RESULTS: Of 149 patients hospitalized with influenza A virus infection, 50 patients were enrolled in the study. Most patients were older (median age, 76 years), and almost all (96%) had underlying chronic medical conditions. Of 41 patients included in the final analysis, influenza A virus was detected in 22 (54%) by PCR and in 12 (29%) by culture methods at or beyond 7 days after symptom onset. All 12 patients identified by culture also had PCR results positive for influenza A virus. CONCLUSION: Hospitalized patients with influenza A virus infection can shed detectable virus beyond the 5- to 7-day period traditionally considered the duration of infectivity. Additional research is needed to assess whether prolonging the duration of patient isolation is warranted to prevent nosocomial outbreaks during the influenza season.

Hospital rules-based system: the next generation of medical informatics for patient safety.

PURPOSE: The hospital rules-based system (HRBS) and its subsystems at a major medical center are described. SUMMARY: The HRBS was implemented at the Mayo Clinic to rapidly identify and communicate crucial information to the clinician in order to optimize patient care. The system also enhances workload efficiency and improves documentation and communication. The system is used by the infectious-diseases division, pharmacy services, nutritional support services, infection control, and the nursing department. The six HRBS subsystems are Web-based programs that share a common structural design and integrate computerized information from multiple institutional databases. The integrated data are presented in a user-friendly format that improves the efficiency of data retrieval. Information, such as monitoring notes and intervention information, can be entered for specific patients. The subsystems use rules designed to detect suboptimal therapy or monitoring and identify opportunities for cost savings in a timely manner. CONCLUSION: The HRBS enhances the identification of drug-related problems while optimizing patient care and improving communication and efficiency at a major medical center.

SARS: epidemiology, clinical presentation, management, and infection control measures.

Severe acute respiratory syndrome (SARS) is a recently recognized febrile respiratory illness that first appeared in southern China in November 2002, has since spread to several countries, and has resulted in more than 8000 cases and more than 750 deaths. The disease has been etiologically linked to a novel coronavirus that has been named the SARS-associated coronavirus. It appears to be spread primarily by large droplet transmission. There is no specific therapy, and management consists of supportive care. This article summarizes currently available information regarding the epidemiology, clinical features, etiologic agent, and modes of transmission of the disease, as well as infection control measures appropriate to contain SARS.

Q fever endocarditis in the United States.

Infections due to Coxiella burnetii, the causative organism of Q fever, are extremely rare in North America. Endocarditis due to the organism has an unusual presentation and poses echocardiographic and laboratory challenges in establishing a diagnosis. We describe the presentation and clinical course of a 40-year-old American man with Q fever endocarditis and briefly discuss the salient issues regarding this entity.

Surgical management of abdominal tuberculosis.

Recent reports suggest an increased incidence of abdominal tuberculosis in the United States, particularly in high-risk groups. The aim of this study was to review the spectrum of abdominal tuberculosis and its surgical management at a tertiary referral center in the United States. The medical records of patients treated for abdominal tuberculosis at our institution between January 1992 and June 2001 were retrospectively reviewed. Eighteen patients were diagnosed with abdominal tuberculosis by microbiologic and/or histologic examination. The 10 men and eight women had a mean duration of symptoms of 4 months (range 1 to 24 months). Five were born in the United States, and 13 were foreign born (7 Asians and 6 Africans). The United States-born patients with abdominal tuberculosis, as compared to the foreign-born patients, were older (mean age 74 years vs. 35 years), more likely to have chronic medical illnesses (80% vs. 7%), and had concomitant pulmonary tuberculosis (60% vs. 0%). Computed tomography was the most frequent imaging modality (88%); findings suggestive of abdominal tuberculosis were mesenteric/omental stranding (50%), ascites (37%), and retroperitoneal lymphadenopathy (31%). Seventeen of the 18 patients required operative intervention, and one patient underwent CT-guided drainage of a psoas abscess. Laparoscopy was useful for diagnosis in eight patients; laparotomy was performed for complications of abdominal tuberculosis in six patients and to obtain a tissue diagnosis in three patients. Abdominal tuberculosis continues to represent a diagnostic challenge to clinicians. Among native-born white Americans, abdominal tuberculosis is primarily a disseminated disease of elderly, debilitated patients with chronic illnesses. Among foreign-born individuals, abdominal tuberculosis occurs in young, immunocompetent patients from endemic areas. Characteristic CT findings should be evaluated for abdominal tuberculosis in the appropriate clinical setting. Laparoscopy is an effective modality for diagnosis of peritoneal tuberculosis.

A cluster of Mycobacterium wolinskyi surgical site infections at an academic medical center.

OBJECTIVE: To study a cluster of Mycobacterium wolinskyi surgical site infections (SSIs). DESIGN: Observational and case-control study. SETTING: Academic hospital. PATIENTS: Subjects who developed SSIs with M. wolinskyi following cardiothoracic surgery. METHODS: Electronic surveillance was performed for case finding as well as electronic medical record review of infected cases. Surgical procedures were observed. Medical chart review was conducted to identify risk factors. A case-control study was performed to identify risk factors for infection; Fisher exact or Kruskal-Wallis tests were used for comparisons of proportions and medians, respectively. Patient isolates were studied using pulsed-field gel electrophoresis (PFGE). Environmental microbiologic sampling was performed in operating rooms, including high-volume water sampling. RESULTS: Six definite cases of M. wolinskyi SSI following cardiothoracic surgery were identified during the outbreak period (October 1, 2008-September 30, 2011). Having cardiac surgery in operating room A was significantly associated with infection (odds ratio, 40; P = .0027). Observational investigation revealed a cold-air blaster exclusive to operating room A as well a microbially contaminated, self-contained water source used in heart-lung machines. The isolates were indistinguishable or closely related by PFGE. No environmental samples were positive for M. wolinskyi. CONCLUSIONS: No single point source was established, but 2 potential sources, including a cold-air blaster and a microbially contaminated, self-contained water system used in heart-lung machines for cardiothoracic operations, were identified. Both of these potential sources were removed, and subsequent active surveillance did not reveal any further cases of M. wolinskyi SSI.

Should national standards for reporting surgical site infections distinguish between primary and revision orthopedic surgeries?

OBJECTIVE: To compare the surgical site infection (SSI) rate after primary total hip arthroplasty with the SSI rate after revision total hip arthroplasty. DESIGN: Retrospective cohort study. SETTING: Mayo Clinic in Rochester, Minnesota, a referral orthopedic center. PATIENTS: All patients undergoing primary total hip arthroplasty or revision total hip arthroplasty during the period from January 1, 2002, through December 31, 2006. METHODS: We obtained data on total hip arthroplasties from a prospectively maintained institutional surgical database. We reviewed data on SSIs collected prospectively as part of routine infection control surveillance, using the criteria of the Centers for Disease Control and Prevention for the definition of an SSI. We used logistic regression analyses to evaluate differences between the SSI rate after primary total hip arthroplasty and the SSI rate after revision total hip arthroplasty. RESULTS: A total of 5,696 total hip arthroplasties (with type 1 wound classification) were analyzed, of which 1,381 (24%) were revisions. A total of 61 SSIs occurred, resulting in an overall SSI rate of 1.1% for all total hip arthroplasties. When stratified by the National Nosocomial Infection Surveillance (NNIS) risk index, SSI rates were 0.5%, 1.2%, and 1.6% in risk categories 0, 1, and 2, respectively. After controlling for the NNIS risk index, the risk of SSI after revision total hip arthroplasty was twice as high as that after primary total hip arthroplasty (odds ratio, 2.2 [95% confidence interval, 1.3-3.7]). In the analysis restricted to the development of deep incisional or organ space infections, the risk of SSI after revision total hip arthroplasty was nearly 4 times that after primary total hip arthroplasty (odds ratio, 3.9 [95% confidence interval, 2.0-7.6]). CONCLUSION: Including revision surgeries in the calculation of SSI rates can result in higher infection rates for institutions that perform a larger number of revisions. Taking NNIS risk indices into account does not eliminate this effect. Differences between primary and revision surgeries should be considered in national standards for the reporting of SSIs.

Epidemiology and control of pertussis outbreaks in a tertiary care center and the resource consumption associated with these outbreaks.

OBJECTIVE: To describe the epidemiology and control of 2 separate outbreaks of pertussis at a large tertiary care center and the resource consumption associated with these outbreaks. DESIGN: Descriptive study. SETTING: The Mayo Clinic in Rochester, Minnesota, a tertiary care center catering to both referral patients and patients from the community. METHODS: We reviewed routine and enhanced surveillance data collected by infection prevention and control practitioners during the outbreaks. Pertussis was diagnosed either on the basis of a nasopharyngeal specimen positive for Bordetella pertussis by use of polymerase chain reaction (PCR) or on the basis of a compatible clinical syndrome along with an epidemiologic link to PCR-confirmed cases. RESULTS: Two pertussis outbreaks, the first community based and the second hospital based (ie, due to transmission among healthcare personnel), occurred during the period from October 2004 through October 2005. In the first outbreak from November 2004 through March 2005, there were 109 cases diagnosed; 105 (96%) of these cases were diagnosed on the basis of a nasopharyngeal specimen positive for B. pertussis by use of PCR. Adolescents 10-19 years of age were most affected (77 cases [71%]). Only 13 cases (12%) occurred among healthcare personnel; however, many healthcare personnel required postexposure prophylaxis. A second outbreak of 122 cases occurred during the period from July through October 2005; of these 122 cases, 96 (79%) were diagnosed on the basis of a nasopharyngeal specimen positive for B. pertussis by use of PCR, and 64 (52%) involved healthcare personnel. There were many instances of transmission among healthcare personnel and from patients to healthcare personnel, but no documented transmission from healthcare personnel to patients. The outbreaks were controlled by aggressive case finding, treatment of those infected, prophylaxis of all healthcare personnel and patients who had contact with both probable and confirmed cases, implementation of educational efforts, and compliance with respiratory etiquette. Vaccination of healthcare personnel against pertussis began in October 2005. CONCLUSION: Pertussis remains a public health problem. Outbreaks in healthcare facilities consume the resources of those facilities in terms of personnel, testing, treatment of cases, and prophylaxis of those individuals who were in contact with those cases. Adult vaccination may reduce the disease burden.

Sternal wound infections.

Deep sternal wound infections (DSWI) continue to be a relatively uncommon event occurring in about 1%-2% of all patients undergoing cardiac surgery. However, the sheer number of cardiac surgery patients and the relatively high mortality associated with DSWIs makes them of clinical relevance. This review will describe the current incidence of DSWIs and their associated morbidity and mortality as well as risk factors for the development of this complication. The microbiology of DSWIs will be reviewed and strategies to prevent these complications will be discussed with a focus on interventions that may be undertaken by the clinical anesthesiologist.