[Show abstract][Hide abstract] ABSTRACT: Blood stream infections (BSIs) are a common source of morbidity and death in hospitalized patients. We hypothesized that the proportions of bacteremia from gram-positive and fungal pathogens have decreased over time, whereas rates of gram-negative bacteremia have increased as a result of better central venous catheter management.
All U.S. Centers for Disease Control and Prevention-defined BSIs in patients treated on the general surgery and trauma services at our institution between January 1, 1998, and December 31, 2009 were identified prospectively. These cases were analyzed on a yearly basis to compare rates of various infections over time. The Cochran-Armitage test for trend was used to evaluate categorical data, whereas the Jonckheere-Terpstra test for ordered values was used to analyze continuous data.
A total of 1,040 patients had 1,441 episodes of BSI caused by 1,632 strains of bacteria or fungi. There was no difference over time in the proportion of BSI among overall infections. Rates of BSI for gram-negative and fungal pathogens increased over time (p=0.03 and<0.0001, respectively), whereas rates of gram-positive BSI decreased (p<0.0001). Positive changes in anaerobic BSI approached statistical significance.
Although our hypothesis was only partly true, over the last 12 y, our institution clearly has witnessed a shift in the types of organisms causing BSIs. There was a decrease in the rates of BSI caused by gram-positive pathogens with an associated increase in the rates of BSI of infections by fungal and gram-negative pathogens. Interventions to reduce institutional rates of BSI should include targeted therapies based on historical institutional trends.
[Show abstract][Hide abstract] ABSTRACT: Background:
We hypothesized that a longer duration of antibiotic treatment for intra-abdominal infections (IAI) would be associated with an increased risk of extra-abdominal infections (EAI) and high mortality.
We reviewed all IAI occurring in a single institution between 1997 and 2010. The IAI were divided into two groups consisting of those with a subsequent EAI and those without; the data for each group were analyzed. Patients with EAI following IAI were matched in a 1:2 ratio with patients who did not develop EAI on the basis of their Acute Physiology and Chronic Health Evaluation (APACHE II) score±1 point. Statistical analyses were done with the Student t-test, χ(2) analysis, Wilcoxon rank sum test, and multi-variable analysis.
We identified 2,552 IAI, of which 549 (21.5%) were followed by EAI. Those IAI that were followed by EAI were associated with a longer initial duration of antimicrobial therapy than were IAI without subsequent EAI (median 14 d [inter-quartile range (IQR) 10-22 d], vs. 10 d [IQR 6-15 d], respectively, p<0.01), a higher APACHE II score (16.6±0.3 vs. 11.2±0.2 points, p<0.01), and higher in-hospital mortality (17.1% vs. 5.4%, p<0.01). The rate of EAI following IAI in patients treated initially with antibiotics for 0-7 d was 13.3%, vs. 25.1% in patients treated initially for >7 d (p<0.01). A successful match was made of 469 patients with subsequent EAI to 938 patients without subsequent EAI, resulting in a mean APACHE II score of 15.2 for each group. After matching, IAI followed by EAI were associated with a longer duration of initial antimicrobial therapy than were IAI without subsequent EAI (median 14 d [9-22 d], vs. 11 d [7-16 d], respectively, p<0.01), and with a higher in-hospital mortality (14.9% vs. 9.0%, respectively, p<0.01). Logistic regression showed that days of antimicrobial therapy for IAI was an independent predictor of subsequent EAI (p<0.001).
A longer duration of antibiotic therapy for IAI is associated with an increased risk of subsequent EAI and increased mortality.
[Show abstract][Hide abstract] ABSTRACT: Background:
Aspergillus infections are associated commonly with immunocompromised states, such as transplantation and hematologic malignant disease. Although Aspergillus infections among patients having surgery occur primarily in transplant recipients, they are found in non-recipients of transplants, and have a mortality rate similar to that seen among transplant recipients.
We conducted a retrospective analysis of a prospective data base collected from 1996 to 2010, in which we identified patients with Aspergillus infections. We compared demographic data, co-morbidities, and outcomes in non-transplant patients with those in abdominal transplant recipients. Continuous data were evaluated with the Student t-test, and categorical data were evaluated through χ(2) analysis.
Twenty-three patients (11 transplant patients and 12 non-transplant patients) were identified as having had Aspergillus infections. The two groups were similar with regard to their demographics and co-morbidities, with the exceptions of their scores on the Acute Physiology and Chronic Health Evaluation II (APACHE II), of 23.6±8.1 points for transplant patients vs. 16.8±6.1 points for non-transplant patients (p=0.03); Simplified Acute Physiology Score (SAPS) of 16.6±8.3 points vs. 9.2±4.1 points, respectively (p=0.02); steroid use 91.0% vs. 25.0%, respectively (p=0.003); and percentage of infections acquired in the intensive care unit (ICU) 27.3% vs. 83.3%, respectively (p=0.01). The most common site of infection in both patient groups was the lung. The two groups showed no significant difference in the number of days from admission to treatment, hospital length of stay following treatment, or mortality.
Although Aspergillus infections among surgical patients have been associated historically with solid-organ transplantation, our data suggest that other patients may also be susceptible to such infections, especially those in an ICU who are deemed to be critically ill. This supports the idea that critically ill surgical patients exist in an immunocompromised state. Surgical intensivists should be familiar with the diagnosis and treatment of Aspergillus infections even in the absence of an active transplant program.
[Show abstract][Hide abstract] ABSTRACT: Analysis and modeling of data monitoring vital signs and waveforms in patients in a surgical/trauma intensive care unit (STICU) may allow for early identification and treatment of patients with evolving respiratory failure.
Between February 2011 and March 2012, data of vital signs and waveforms for STICU patients were collected. Every-15-minute calculations (n = 172,326) of means and standard deviations of heart rate (HR), respiratory rate (RR), pulse-oxygen saturation (SpO2), cross-correlation coefficients, and cross-sample entropy for HR-RR, RR-SpO2, and HR-SpO2, and cardiorespiratory coupling were calculated. Urgent intubations were recorded. Univariate analyses were performed for the periods <24 and ≥24 hours before intubation. Multivariate predictive models for the risk of unplanned intubation were developed and validated internally by subsequent sample and bootstrapping techniques.
Fifty unplanned intubations (41 patients) were identified from 798 STICU patients. The optimal multivariate predictive model (HR, RR, and SpO2 means, and RR-SpO2 correlation coefficient) had a receiving operating characteristic (ROC) area of 0.770 (95% confidence interval [CI], 0.712-0.841). For this model, relative risks of intubation in the next 24 hours for the lowest and highest quintiles were 0.20 and 2.95, respectively (15-fold increase, baseline risk 1.46%). Adding age and days since previous extubation to this model increased ROC area to 0.865 (95 % CI, 0.821-0.910).
Among STICU patients, a multivariate model predicted increases in risk of intubation in the following 24 hours based on vital sign data available currently on bedside monitors. Further refinement could allow for earlier detection of respiratory decompensation and intervention to decrease preventable morbidity and mortality in surgical/trauma patients.
Surgery 09/2013; 154(5). DOI:10.1016/j.surg.2013.05.025 · 3.38 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Background:
The use of silver for the treatment of various maladies or to prevent the transmission of infection dates back to at least 4000 b.c.e. Medical applications are documented in the literature throughout the 17th and 18th centuries. The bactericidal activity of silver is well established. Silver nitrate was used topically throughout the 1800 s for the treatment of burns, ulcerations, and infected wounds, and although its use declined after World War II and the advent of antibiotics, Fox revitalized its use in the form of silver sulfadiazine in 1968.
Review of the pertinent English-language literature.
Since Fox's work, the use of topical silver to reduce bacterial burden and promote healing has been investigated in the setting of chronic wounds and ulcers, post-operative incision dressings, blood and urinary catheter designs, endotracheal tubes, orthopedic devices, vascular prostheses, and the sewing ring of prosthetic heart valves. The beneficial effects of silver in reducing or preventing infection have been seen in the topical treatment of burns and chronic wounds and in its use as a coating for many medical devices. However, silver has been unsuccessful in certain applications, such as the Silzone heart valve. In other settings, such as orthopedic hardware coatings, its benefit remains unproved.
Silver remains a reasonable addition to the armamentarium against infection and has relatively few side effects. However, one should weigh the benefits of silver-containing products against the known side effects and the other options available for the intended purpose when selecting the most appropriate therapy.
[Show abstract][Hide abstract] ABSTRACT: Ventilator-associated pneumonia (VAP) is the most common hospital-acquired infection in the intensive care unit, with substantial subsequent mortality. The mortality following VAP declined in the 1980s and 1990s. Experts suggest that little progress has been made in the outcomes from VAP since several novel interventions have failed. We nonetheless hypothesized that mortality following VAP has continued to decrease owing to advances in pulmonary critical care.
We identified all adult patients with Centers for Disease Control and Prevention-defined, intensive care unit-acquired VAP between January 1, 1997, and December 31, 2008, from a prospectively collected database.
A total of 793 cases of VAP occurred in the study period. Cases were divided into four periods (1997-1999, 2000-2002, 2003-2005, or 2006-2008) to compare outcomes over time. Acute Physiology and Chronic Health Evaluation II scores were stable, while mortality was significantly lower in Period 4 when compared with Periods 1 and 2 (p = 0.004 and 0.009, respectively). A logistic regression model predicting death (c statistic = 0.871) revealed age (odds ratio, 1.03; 95% confidence interval, 1.02-1.05), Acute Physiology and Chronic Health Evaluation II score (1.09, 1.05-1.14), white blood cell count (1.03, 1.00-1.06), transplant recipient (3.45, 1.40-8.53), transfusions (3.25, 1.37-7.68), and pulmonary disease (3.01, 1.67-5.45) were independent predictors of death, as was the presence of trauma (0.10, 0.06-0.18), chronic steroid therapy (0.39, 0.17-0.91), and patient length of stay (0.99, 0.98-0.99), with odds ratios less than 1.0. In addition, those patients treated in Period 1 (2.23, 1.16-4.29) or Period 2 (2.13, 1.12-4.06) had twice the risk of death following an episode of VAP when compared with those treated in the most recent period.
We have shown that mortality following an episode of VAP continues to decrease over time and attribute this to advancements in pulmonary and general critical care rather than any specific interventions.
Prognostic study, level II.
[Show abstract][Hide abstract] ABSTRACT: Background:
The infected abdomen poses substantial challenges to surgeons, and often, both temporary and definitive closure techniques are required. We reviewed the options available to close the abdominal wall defect encountered frequently during and after the management of complicated intra-abdominal infections.
A comprehensive review was performed of the techniques and literature on abdominal closure in the setting of intra-abdominal infection.
Temporary abdominal closure options include the Wittmann Patch, Bogota bag, vacuum-assisted closure (VAC), the AbThera™ device, and synthetic or biologic mesh. Definitive reconstruction has been described with mesh, components separation, and autologous tissue transfer.
Reconstructing the infected abdomen, both temporarily and definitively, can be accomplished with various techniques, each of which is associated with unique advantages and disadvantages. Appropriate judgment is required to optimize surgical outcomes in these complex cases.
[Show abstract][Hide abstract] ABSTRACT: Anatomic popliteal artery entrapment can be challenging to diagnose. Four cases are described in which initial diagnosis and treatment failed to identify and correct the anatomic defect responsible for patients' symptoms. In 3 of these cases, initial assessment and diagnosis was exertional compartment syndrome, yet compartment release did not resolve the complaint. Following accurate diagnosis, surgical release of aberrant popliteal fossa anatomy provided all 4 patients with lasting symptom resolution, though 1 patient with bilateral operations has had relief of only 1 side. In the diagnostic algorithm for these patients, angiography with forced plantarflexion against resistance aids in eliciting the pathognomonic images of arterial occlusion in this disorder.
Vascular and Endovascular Surgery 08/2012; 46(7):542-5. DOI:10.1177/1538574412457472 · 0.66 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Antimicrobial treatment in critically ill patients can either be started as soon as infection is suspected or after objective data confirm an infection. We postulated that delaying antimicrobial treatment of patients with suspected infections in the surgical intensive care unit (SICU) until objective evidence of infection had been obtained would not worsen patient mortality.
We did a 2-year, quasi-experimental, before and after observational cohort study of patients aged 18 years or older who were admitted to the SICU of the University of Virginia (Charlottesville, VA, USA). From Sept 1, 2008, to Aug 31, 2009, aggressive treatment was used: patients suspected of having an infection on the basis of clinical grounds had blood cultures sent and antimicrobial treatment started. From Sept 1, 2009, to Aug 31, 2010, a conservative strategy was used, with antimicrobial treatment started only after objective findings confirmed an infection. Our primary outcome was in-hospital mortality. Analyses were by intention to treat.
Admissions to the SICU for the first and second years were 762 and 721, respectively, with 101 patients with SICU-acquired infections during the aggressive year and 100 patients during the conservative year. Compared with the aggressive approach, the conservative approach was associated with lower all-cause mortality (13/100 [13%] vs 27/101 [27%]; p=0·015), more initially appropriate therapy (158/214 [74%] vs 144/231 [62%]; p=0·0095), and a shorter mean duration of therapy (12·5 days [SD 10·7] vs 17·7 [28·1]; p=0·0080). After adjusting for age, sex, trauma involvement, acute physiology and chronic health evaluation (APACHE) II score, and site of infection, the odds ratio for the risk of mortality in the aggressive therapy group compared with the conservative therapy group was 2·5 (95% CI 1·5-4·0).
Waiting for objective data to diagnose infection before treatment with antimicrobial drugs for suspected SICU-acquired infections does not worsen mortality and might be associated with better outcomes and use of antimicrobial drugs.
National Institutes of Health.
[Show abstract][Hide abstract] ABSTRACT: Isolation is defined as the separation of persons with communicable diseases from those who are healthy. This public health practice, along with quarantine, is used to limit the transmission of infectious diseases and provides the foundation of current-day cohorting.
Review of the pertinent English-language literature.
Mass isolation developed during the medieval Black Death outbreaks in order to protect ports from the transmission of epidemics. In the mid-1800s, infectious disease hospitals were opened. It now is clear that isolation and cohorting of patients and staff interrupts the transmission of disease. Over the next century, with the discovery of penicillin and vaccines against many infectious agents, the contagious disease hospitals began to close. Today, we find smaller outbreaks of microorganisms that have acquired substantial resistance to antimicrobial agents. In the resource-limited hospital, a dedicated area or region of a unit may suffice to separate affected from unaffected patients.
Quarantine, or cohorting when patients are infected with the same pathogen, interrupts the spread of infections, just as the contagious disease hospitals did during the epidemics of the 18th and 19th centuries.
[Show abstract][Hide abstract] ABSTRACT: We report the midterm results of external iliac artery reconstruction in 25 high-performance cyclists.
Cyclists undergoing arterial reconstruction for symptomatic external iliac arteriopathy at a single institution between October 2004 and August 2010 were identified. With Institutional Review Board approval, data were collected from medical record review and telephone interview. Results were analyzed with χ(2) or independent t-test.
Twenty-five patients (31 limbs) underwent operation, which included arterial reconstruction with or without inguinal ligament release. The average patient age at operation was 43.8 ± 5.0 for graft and 35.1 ± 1.9 for patch (P = .08). The average time from competitive cycling until operation was 18.2 ± 5.8 years for graft and 20.0 ± 2.5 for patch repairs (NS). Patients included 14 males and 11 females. There were 23 unilateral and four bilateral arterial reconstructions, including 26 patch angioplasties for localized disease and five interposition grafts for extensive disease; three patients underwent contralateral reconstruction as a separate procedure. Concomitant ipsilateral inguinal ligament release was performed in 25 patients (28 limbs), with contralateral release done in 12 patients (12 limbs). Three patients with isolated ligament release required subsequent arterial intervention. Follow-up averaged 32 months (range, 2-74). Primary patency for all reconstructions was 100%; the four reoperations (five limbs; one bilateral) were for symptom recurrence, two postgraft and two postangioplasty. Three reoperations were for recurrent intimal hyperplasia, one for disease distal to the anastomosis, and one for concomitant atherosclerotic disease. Based on available data, postexercise ankle-brachial indices were improved in 18 of 23 limbs. Seventeen patients completed questions regarding satisfaction: 10 were satisfied or very satisfied (zero graft, 10 patch; P = .25), while four were unsatisfied (three graft, two patch; P = .017, including one patient with both a patch and graft repair). All 20 patients for whom follow-up data were available are still cycling, 10 competitively. Two of the four reoperated patients were unsatisfied; all four are still cycling, one competitively.
External iliac arteriopathy is a disease of prolonged, sustained, and repetitive trauma. Patch angioplasty yields a low rate of reoperation, more satisfied patients, return to competitive activity, and improvement in postexercise ankle-brachial indices. Interposition grafting is associated with slightly older patients, more extensive disease, and less satisfying results. Intimal hyperplasia is the most frequent complication necessitating reoperation. Both the decision to pursue arterial reconstruction and patient expectations must be tempered by the pattern of disease and the potential for unsatisfactory results.
Journal of vascular surgery: official publication, the Society for Vascular Surgery [and] International Society for Cardiovascular Surgery, North American Chapter 03/2012; 55(5):1338-44; discussion 1344-5. DOI:10.1016/j.jvs.2011.11.106 · 3.02 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Cohorting patients in dedicated hospital wards or wings during infection outbreaks reduces transmission of organisms, yet frequently, this may not be feasible because of inadequate capacity, especially in the intensive care unit (ICU). We hypothesized that cohorting isolation patients in one geographic location in a single ICU and using enhanced isolation procedures ("superisolation") can prevent the further spread of highly multi-drug-resistant organisms (MDRO).
Six patients dispersed throughout our Surgical Trauma Burn ICU had infections with carbapenem-resistant, non-clonal gram-negative MDRO, namely Klebsiella pneumoniae, Citrobacter freundii, Stenotrophomonas maltophilia, Aeromonas hydrophilia, Proteus mirabilis, Pseudomonas aeruginosa, and Providencia rettgeri. Five of the six patients also had simultaneous isolation of vancomycin-resistant enterococci (VRE). Under threat of unit closure and after all standard isolation procedures had been enacted, these six patients were moved to the front six beds of the unit, the front entrance was closed, and all traffic was redirected through the back entrance. Nursing staff were assigned to either two isolation or two non-isolation patients. In accordance with the practice of Semmelweis, rounds were conducted so as to end at the rooms of the patients with the most highly-resistant bacterial infections.
A few months after these interventions, all six patients had been discharged from the ICU (three alive and three dead), and no new cases of infection with any of their pathogens (based on species and antibiogram) or VRE occurred. The mean ICU stay and overall hospital length of stay for these six patients were 78.3 days and 117.2 days respectively, with a mortality rate of 50%.
Cohorting patients to one area and altering work routines to minimize contact with patients with MDRO (essentially designating a "high-risk" zone) may be beneficial in stopping patient-to-patient spread of highly resistant bacteria without the need for a dedicated isolation unit.
[Show abstract][Hide abstract] ABSTRACT: Intra-abdominal infections following surgical procedures result from organ-space surgical site infections, visceral perforations, or anastomotic leaks. We hypothesized that open surgical drainage is associated with increased patient morbidity and mortality compared with percutaneous drainage. A single-institution, prospectively collected database over a 13-year period revealed 2776 intra-abdominal infections, 686 of which required an intervention after the index operation. Percutaneous procedures (simple aspiration or catheter placement) were compared with all other open procedures by univariate and multivariate analyses. Analysis revealed 327 infections in 240 patients undergoing open surgical drainage and 359 infections in 260 patients receiving percutaneous drainage. Those undergoing open drainage had significantly higher Acute Physiology Score (APS) and Acute Physiology and Chronic Health Evaluation (APACHE) II scores and were more likely to be immunosuppressed, require intensive care unit treatment, and have longer hospital stays. Mortality was higher in the open group: 14.6 versus 4.2 per cent (P = 0.0001). Variables independently associated with death by multivariate analysis were APACHE II, dialysis, intensive care unit (ICU) care, age, immunosuppression, and drainage method. Open intervention for postsurgical intra-abdominal infections is associated with increased mortality compared with percutaneous drainage even after controlling for severity of illness by multivariate analysis. Although some patients are not candidates for percutaneous drainage, it should be considered the preferential treatment in eligible patients.
The American surgeon 07/2011; 77(7):862-7. · 0.82 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: In response to inconsistent compliance with infection prevention measures, the Centers for Medicare & Medicaid Services collaborated with the U.S. Centers for Disease Control and Prevention on the Surgical Infection Prevention (SIP) project, introduced in 2002.
Quality improvement measures were developed to standardize processes to increase compliance. In 2006, the Surgical Care Improvement Project (SCIP) developed out of the SIP project and its process measures. These initiatives, published in the Specifications Manual for National Inpatient Quality Measures, outline process and outcome measures. This continually evolving manual is intended to provide standard quality measures to unify documentation and track standards of care.
Seven of the SCIP initiatives apply to the peri-operative period: Prophylactic antibiotics should be received within 1 h prior to surgical incision (1), be selected for activity against the most probable antimicrobial contaminants (2), and be discontinued within 24 h after the surgery end-time (3); (4) euglycemia should be maintained, with well-controlled morning blood glucose concentrations on the first two post-operative days, especially in cardiac surgery patients; (6) hair at the surgical site should be removed with clippers or by depilatory methods, not with a blade; (9) urinary catheters are to be removed within the first two post-operative days; and (10) normothermia should be maintained peri-operatively.
There is strong evidence that implementation of protocols that standardize practices reduce the risk of surgical infection. The SCIP initiative targets complications that account for a significant portion of preventable morbidity as well as cost. One of the goals of the SCIP guidelines was a 25% reduction in the incidence of surgical site infections from implementation through 2010. Process measures are becoming routine, and as we practice more evidence-based medicine, it falls to us, the surgeons and scientists, to be active, not only in the implementation and execution of these measures, but in the investigation of clinical questions and the writing of protocols. We are responsible for ensuring that out-of-date practices are removed from use and that new practices are appropriate, achievable, and effective.
[Show abstract][Hide abstract] ABSTRACT: Novexel is developing the novel, orally active, semisynthetic streptogramin NXL-103, which has potential therapeutic application in the treatment of community-acquired pneumonia, community- or hospital-acquired MRSA, vancomycin-resistant enterococcus, and acute bacterial skin and soft tissue infections. NXL-103 is a combination of streptogramin A:streptogramin B components, initially developed in a 70:30 dose ratio. In multiple in vitro studies, NXL-103 demonstrated potent activity against different types of bacteria, such as Staphylococcus aureus (including MRSA), Streptococcus pneumoniae, Streptococcus pyogenes, Enterococcus faecium, Enterococcus faecalis, Haemophilus influenzae and Haemophilus parainfluenzae. NXL-103 was not affected by the resistance profiles of bacteria against other commonly used antibiotics. In phase I clinical trials, NXL-103 achieved bactericidal levels in plasma and was generally well tolerated, with side effects primarily on the gastrointestinal system. The first phase II trial conducted to evaluate the efficacy of NXL-103 against community-acquired pneumonia revealed that the compound was comparable with amoxicillin. NXL-103 has promise to become an important agent in the treatment of community-acquired pneumonia and complex skin and soft tissue infections, pending further development.
Current opinion in investigational drugs (London, England: 2000) 02/2010; 11(2):225-36. · 3.55 Impact Factor