Massive transfusion associated with a hemolytic transfusion reaction: necessary precautions for prevention.

CASE REPORT: A 45-year-old male presented in severe hypovolemic shock after a thoracoabdominal gunshot wound. The massive transfusion protocol (MTP) was activated and the patient was taken to the operating room. His major injuries included liver, small bowel, and right common iliac vein. Hemorrhage was stopped and a damage control laparotomy was completed. He received a total of 113 blood products. During his postoperative course he received a group B blood transfusion on Hospital Days 2 and 7 based on incorrect blood typing late in his massive transfusion and repeat testing on Day 4. RESULTS: He succumbed to multiple organ failure on Day 8. MTPs are standard in most trauma centers during which universal donor red blood cells are initially used. As hemorrhage is controlled, the patient undergoes a complete type and cross according to blood banking protocols. These typing results are used to continue transfusions once the MTP is no longer needed. In contacting other blood banks servicing Level I trauma centers, the policy of when to switch from universal donor blood to crossmatched blood is variable. CONCLUSION: Our case illustrates a potential blood typing problem that had a disastrous outcome. We identified changes in policy that will make MTPs safer.

Management of High Grade Splenic Injuries in Rural America.

BACKGROUND: Rural surgeons face unique challenges when managing patients with high-grade (III-V) blunt splenic injury (BSI) given limited access to interventional radiology and blood products. Patients therefore may require transfer for splenic artery embolization (SAE) when resuscitation may still be ongoing. This study aims to evaluate current resource utilization in a rural trauma population with limited access to SAE and blood products. METHODS: Retrospective analysis of adult patients with high-grade BSI at one Level 1 trauma center and two Level 2 trauma centers was performed. Patients were evaluated for resources used after transfer to the regional trauma center. Primary outcomes measured were SAE, operative management (OM), and blood product utilization. Secondary outcomes measured included injury severity score (ISS) and mortality. RESULTS: Final analysis included 134 transferred patients. 16% underwent SAE, 16% underwent OM, and 69% were treated successfully with nonoperative and non-procedural management (NOM). 52% of the SAE patients had sustained a grade III splenic injury, 38% grade IV, and 10% grade V. 84% of patients required <3 units of packed red blood cells (PRBC) and 57% of patients required none. 80% of transferred patients required <3 total units of all combined blood products. DISCUSSION: The majority of patients with BSI transferred to a tertiary trauma center from a rural facility were successfully managed without SAE and required minimal transfusion of blood products. In the absence of other injuries necessitating transfer to a tertiary trauma center, rural surgeons should consider management of high grade splenic injuries at their home institution.

Screening for blunt cerebrovascular injuries is cost-effective.

BACKGROUND: Screening for blunt carotid and vertebral injury (BCVI) is increasing without a clear understanding of whether the chosen screening approach is cost-effective. We hypothesized that screening for BCVI using computed tomography angiography (CTA) was cost-effective in populations at high risk for BCVI. METHODS: A decision analysis was performed modeling current BCVI screening approaches: no screening, duplex ultrasound, magnetic resonance angiography, angiography, and CTA. Treatment options included antiplatelet therapy, anticoagulation, stents for pseudoaneurysm, and no treatment. Probability estimates for incidence of injury and stroke, sensitivity and specificity of the screening modality, and type of treatment were taken from published data. Average wholesale price and medicare reimbursement costs were used. Two populations were analyzed; high-risk and overall blunt trauma populations. Two perspectives were taken; societal (including lifetime stroke costs) and institutional (ignoring lifetime stroke costs). RESULTS: In the high-risk population, from a societal perspective, CTA has the lowest cost and stroke rate; $3,727 per patient screened with a 1% stroke rate. No treatment has the highest cost and stroke rate. From an institutional perspective, no screening is the least costly option but has an 11% stroke rate. Duplex ultrasound is the most cost-effective screening modality; $8,940 per stroke prevented. CONCLUSION: From the societal perspective, CTA is the most cost-effective screening strategy for patients at high risk for BCVI. From an institutional perspective, CTA prevents the most strokes at a reasonable cost.

Venous thromboembolism prophylaxis in surgical patients: identifying a patient group to maximize performance improvement.

BACKGROUND: Venous thromboembolism (VTE) in surgical patients is a cause of increased morbidity, mortality, and cost of care. Deep vein thrombosis (DVT) prophylaxis reduces the risk of DVT or pulmonary embolism (PE), but not to zero, which is concerning because DVT/PE is being considered a serious reportable event. A study was conducted in January-June 2009 to test the hypothesis that most surgical VTEs occur despite the patient's receiving appropriate prophylaxis. METHODS: All patients with a surgical diagnosis-related group (DRG) who had a documented DVT/PE in 2008 were retrospectively reviewed. Each VTE episode was characterized as occurring during the index admission for surgery or being present on admission (POA). DVT prophylaxis compliance was measured in all patients who had a procedure at the institution, a 454-bed university teaching hospital, and those patients were classified in terms of compliance with our VTE protocols. Class 1 patients had VTE protocols followed; Class 2 patients had contraindications to VTE protocols documented; Class 3 patients should have received VTE prophylaxis but did not; and Class 4 patients had contraindications to VTE prophylaxis that were not documented. RESULTS: Some 156 (6.3%) of 2,474 surgical patients had a DVT/PE in 2008; for the 144 patients with complete records for review, 89 were candidates for VTE prophylaxis. Some 77 of the 89 patients had received appropriate VTE prophylaxis or had documented contraindications to prophylaxis. Eleven (12.4%) patients who should have received VTE prophylaxis did not. CONCLUSIONS: Compliance with VTE protocols continues to be less than 100%, and even when patients adhere to existing protocols VTE events continue to occur.

Intraabdominal vascular injury: are we getting any better?

BACKGROUND: Intraabdominal vascular injury (IAVI) as a result of penetrating and blunt trauma carries a high mortality rate. This study was performed to compare current mortality rates with a previously reported historic control. METHODS: The experience at our institution from 1970 to 1981 was previously reported with an overall mortality rate of 32% in 112 patients with penetrating IAVI. In a retrospective analysis, this historic cohort was compared with 248 patients with penetrating and blunt IAVI during a 138-month interval ending in June 2007. RESULTS: Overall mortality rate was 28.6%. The most commonly injured arteries were the iliac artery, aorta, and superior mesenteric artery. The most commonly injured veins were the inferior vena cava, iliac vein, and portal vein. Injury to the aorta, IVC, and portal vein had the highest mortality rates of 67.8%, 42.1%, and 66.6%, respectively. One hundred forty-four patients with one vessel injured had a mortality rate of 18.7%, whereas those with more than one vessel injured had a mortality rate of 48.7% (p < 0.001). A total of 46% of 117 patients in shock died compared with 9.6% of 104 patients not in shock (p < 0.001). Patients with a base deficit of less than -15 had a mortality rate of 72%, whereas those with a base deficit of 0 to -15 (p < 0.001) had a mortality rate of 18.9%. There was no difference in the overall mortality rate for penetrating trauma compared with the previous study. CONCLUSIONS: Although over 20 years have passed, no significant changes have occurred in the mortality associated with IAVI. Patients presenting in shock with IAVI continue to have a high mortality rate.

Initial and Ongoing Training of the Rural Surgeon.

Over the last 2 decades, rural locations have realized a steady decrease in surgical access and direct care. Owing to societal expectations for equal general and subspecialty surgical care in urban or rural areas, the ability to attract, train, and hold onto the rural surgeon has come into question. Our current general surgery training curriculum has been reevaluated as to its relevance for rural surgery and several alternatives to the traditional surgical training model have been proposed. The authors discuss and evaluate current and proposed methods for surgical training curriculums and methods for rural surgeon retention through continuing education models.

Analysis of Academic Medical Center Graduate Medical Education Websites for Policies Regarding Restrictive Covenants in Non-ACGME Fellowships.

BACKGROUND: The topic of restrictive covenants in fellowships that are not approved by the Accreditation Council for Graduate Medical Education (ACGME) has not been studied. OBJECTIVE: To investigate the presence of institutional polices at academic medical centers regarding restrictive covenants in non-ACGME fellowships. METHODS: The graduate medical education (GME) office website of 132 academic medical centers was evaluated and searched for the following as of June 1, 2017: presence of any ACGME residency or fellowship, presence of any non-ACGME fellowship, presence of GME policies and procedures, presence of a restrictive covenant policy, and if that policy applies to non-ACGME fellowships. RESULTS: A total of 96 academic medical centers had non-ACGME fellowships. Of these, 56 prohibit restrictive covenants in non-ACGME fellowships because of either their GME policy or state law. Seven academic medical centers have a GME policy that allows restrictive covenants in non-ACGME fellowships. Two academic medical centers clearly state that fellows in a certain subspecialty fellowship will be required to sign a restrictive covenant. CONCLUSIONS: GME policies at academic medical centers that allow restrictive covenants in non-ACGME fellowships are very uncommon. The practice of having fellows sign a restrictive covenant in a non-ACGME fellowship is in conflict with an American Medical Association ethics statement, ACGME institutional requirement IV.L, and the rules of the San Francisco Match.

Skin, soft tissue, bone, and joint infections in hospitalized patients: epidemiology and microbiological, clinical, and economic outcomes.

BACKGROUND: Infections involving skin, soft tissue, bone, or joint (SSTBJ) are common and often require hospitalization. There are currently few published studies on the epidemiology and clinical and economic outcomes of these infections, whether acquired in the community or healthcare setting, in a large population. OBJECTIVE: To characterize outcomes of culture-proven SSTBJ infection in hospitalized patients, using information from a large database. DESIGN: We identified patients hospitalized in 134 institutions during 2002-2003 for whom specific International Classification of Diseases, Ninth Revision, Clinical Modification diagnosis codes and a culture-positive SSTBJ specimen were recorded. Patients were classified into 4 clinical groups based on the type and clinical severity of infection. Patients in each group were further classified on the basis of whether their infection was community acquired or healthcare associated and whether it was complicated or uncomplicated. RESULTS: We identified 12,506 patients with culture-positive infections and categorized them as having cellulitis (37.3%), osteomyelitis or septic arthritis (22.4%), surgical wound infection (26.1%), device-associated or prosthesis infection (7.2%), or other SSTBJ infection (6.9%). Monomicrobial infection was reported for 59% of patients, 54.6% of whom had Staphylococcus aureus as the etiologic agent. Of all S. aureus isolates recovered, 1,121 (28.0%) of 4,007 were resistant to methicillin. Healthcare-associated infections accounted for 27.2% of cases and were associated with a significantly greater mortality rate, a longer length of stay, and greater hospital charges, compared with community-acquired infections. Patients with a complicated infection (78.4%) had a significantly greater mortality rate, a longer length of stay, and greater hospital charges, compared with patients with an uncomplicated infection. CONCLUSIONS: SSTBJ infections are frequent among hospitalized patients. S. aureus caused infection in more than 50% of the patients studied, and 28.0% of the S. aureus isolates recovered were resistant to methicillin. Healthcare-associated and complicated infections are associated with a significantly higher mortality rate and more prolonged and expensive hospitalizations. These findings could assist in projects to revise current management strategies in order to optimize outcomes while restraining costs.

Length of stay: an appropriate quality measure?

HYPOTHESIS: Although demographic and clinical information are known to affect hospital length of stay (LOS), we hypothesized that LOS after traumatic injury would be significantly influenced by nonclinical factors. DESIGN: Retrospective database analysis. PATIENTS: Trauma patients treated at hospitals participating in data submission to the National Trauma Data Bank. METHODS: The National Trauma Data Bank was queried for all patients older than 18 years with an LOS longer than 48 hours and complete demographic information including age, sex, and race/ethnicity; nonclinical factors including payment type (commercial, Medicaid, Medicare, uninsured, and other) and discharge destination (home, rehabilitation facility, nursing home, and other); and clinical information (body region injured, Injury Severity Score, and Revised Trauma Score). Statistical analysis was performed using generalized linear modeling adjusted for multiple comparisons. MAIN OUTCOME MEASURES: Length of stay greater than the mean. RESULTS: We obtained 313 144 medical records. Mean LOS was 9.6 days. Discharge destination had the greatest effect on LOS. Mean LOS for patients with Medicaid (11.3 days) was significantly longer than for patients with commercial insurance and uninsured patients (each 9.3 days) and patients with Medicare (8.8 days). Length of stay was longer for patients discharged to a nursing home (14.2 days) or rehabilitation facility (11.5 days) compared with those discharged to any other facility (9.6 days). In multivariate analysis, factors significantly associated with extended LOS included age, sex, race/ethnicity, insurance status, discharge destination, and Revised Trauma Score. CONCLUSIONS: Nonclinical factors significantly influence LOS. If LOS is used as a quality measure for injured patients, adjustment for these factors is necessary.

Biomechanics of side impact: injury criteria, aging occupants, and airbag technology.

This paper presents a survey of side impact trauma-related biomedical investigations with specific reference to certain aspects of epidemiology relating to the growing elderly population, improvements in technology such as side airbags geared toward occupant safety, and development of injury criteria. The first part is devoted to the involvement of the elderly by identifying variables contributing to injury including impact severity, human factors, and national and international field data. This is followed by a survey of various experimental models used in the development of injury criteria and tolerance limits. The effects of fragility of the elderly coupled with physiological changes (e.g., visual, musculoskeletal) that may lead to an abnormal seating position (termed out-of-position) especially for the driving population are discussed. Fundamental biomechanical parameters such as thoracic, abdominal and pelvic forces; upper and lower spinal and sacrum accelerations; and upper, middle and lower chest deflections under various initial impacting conditions are evaluated. Secondary variables such as the thoracic trauma index and pelvic acceleration (currently adopted in the United States Federal Motor Vehicle Safety Standards), peak chest deflection, and viscous criteria are also included in the survey. The importance of performing research studies with specific focus on out-of-position scenarios of the elderly and using the most commonly available torso side airbag as the initial contacting condition in lateral impacts for occupant injury assessment is emphasized.

Empiric treatment options in the management of complicated intra-abdominal infections.

Complicated intra-abdominal infections remain a major challenge for surgeons and internists because of their association with high morbidity and mortality. For optimal outcome, these infections require a combination of appropriate and timely surgical source control and adjunctive broad-spectrum antimicrobial therapy. This review discusses criteria for choosing empiric antimicrobial therapy, outlines available treatment options, and highlights new antimicrobial therapies for these infections.

Aligning forces for quality: the Wisconsin way.

Aligning Forces for Quality offers a tremendous opportunity for Wisconsin's health care stakeholders to work together to advance the quality of chronic care. Wisconsin is well-poised to work collaboratively on this initiative, has already taken significant initial steps toward its aims, and has the capacity for further improvement. Together we can make a difference by aligning the forces for quality the Wisconsin way.

Clinical significance of computed tomography contrast extravasation in blunt trauma patients with a pelvic fracture.

INTRODUCTION: Blunt pelvic fractures can be associated with major pelvic bleeding. The significance of contrast extravasation (CE) on computed tomography (CT) is debated. We sought to update our experience with CE on CT scan for the years 2009-2014 to determine the accuracy of CE in predicting the need for angioembolization. METHODS: This is a retrospective review of the trauma registry and our electronic medical record from a Level I trauma center. Patients seen from July 1, 2009, to September 7, 2014, with blunt pelvic fractures and contrast-enhanced CT were included. Standard demographic, clinical, and injury data were obtained. Patient records were queried for CE, performance of angiography, and angioembolization. Positive patients were those where CE was associated with active bleeding requiring angioembolization. All other patients were considered negative. RESULTS: There were 497 patients during the study time period with blunt pelvic fracture meeting inclusion criteria, and 75 patients (15%) had CE. Of those patients with CE, 30 patients (40%) underwent angiography, and 17 patients (23%) required angioembolization. The sensitivity, specificity, positive predictive value, and negative predictive value of CE on CT were 100%, 87.9%, 22.7%, and 100%, respectively. Two patients without CE underwent angiography but did not undergo embolization. Patients with CE had higher mortality (13 vs. 6%, p < 0.05) despite not having higher ISS scores. CONCLUSIONS: This study reinforces that CE on CT pelvis with blunt trauma is common, but many patients will not require angioembolization. The negative predictive value of 100% should be reassuring to trauma surgeons such that if a modern CT scanner is used, and there is no CE seen on CT, then the pelvis will not be a source of hemorrhagic shock. All of these findings are likely due to both increased comfort with observing CEs and the increased sensitivity of modern CT scanners. LEVEL OF EVIDENCE: Therapeutic/care management study, level IV.

Association between Pre-Operative Cefazolin Dose and Surgical Site Infection in Obese Patients.

BACKGROUND: A fixed dose of cefazolin results in serum concentrations that decrease as body mass increases. Current national guidelines suggest a pre-operative cefazolin dose of two grams may be insufficient for patients ≥120 kg; thus a three gram dose is recommended. These recommendations, however, are based on pharmacokinetic rather than outcome data. We evaluate the efficacy of pre-operative cefazolin two gram and three gram doses as measured by the rate of surgical site infection (SSI). PATIENTS AND METHODS: We conducted a retrospective review of adult patients ≥100 kg who were prescribed cefazolin as surgical prophylaxis between September 1, 2012 and May 31, 2013 at an academic medical center. Patients were excluded if cefazolin was prescribed but not administered, had a known infection at the site of surgery, or inappropriately received cefazolin prophylaxis based on surgical indication. The SSIs were identified by documentation of SSI in the medical record or findings consistent with the standard Centers for Disease Control and Prevention definition. Inpatient and outpatient records up to 90 days post-operative were reviewed for delayed SSI. RESULTS: Four hundred eighty-three surgical cases were identified in which pre-operative cefazolin was prescribed. Forty-seven patients were excluded leaving a total of 436 patients for final analysis: 152 in the cefazolin two gram group and 284 in the three gram group. Baseline demographics were similar between groups with a mean follow-up duration of 77 days for both groups. Unadjusted SSI rates were 7.2% and 7.4% (odds ratio [OR] 0.98, p = 0.95), for the two gram and three gram groups, respectively. When differences in follow-up between groups were considered and logistic regression was adjusted with propensity score, there remained no difference in SSI rates (OR 0.87, 95% confidence interval 0.36-2.06, p = 0.77). CONCLUSION: In otherwise similar obese surgical patients weighing ≥100 kg, the administration of a pre-operative cefazolin two gram dose is associated with a similar rate of SSI compared with patients who received a three gram dose.

Effective retention of primary survey skills by medical students after participation in an expanded Trauma Evaluation and Management course.

BACKGROUND: The Trauma Evaluation and Management (TEAM) module orients medical students to the initial assessment of an injured patient. At the Medical College of Wisconsin, a course based on expanded TEAM (eTEAM) was developed for junior medical students. This study determined whether eTEAM improved the ability to perform and retain primary survey skills. METHODS: Objective Structured Clinical Examination methodology was used to compare 2 groups of senior medical students 1 year after receiving either a 2-hour lecture or eTEAM. RESULTS: Students receiving eTEAM performed the primary survey much better than those receiving lecture alone. The overall Objective Structured Clinical Examination scores did not differ between groups. CONCLUSIONS: Medical students participating in eTEAM retained the ability to perform a primary survey in proper sequence 1 year later better than students receiving the information in lecture format only.

The Surgical Learning and Instructional Portfolio (SLIP) as a self-assessment educational tool demonstrating practice-based learning.

PURPOSE: Time constraints on the teaching and evaluation of residents continue to alter the way in which medical knowledge must be imparted and assessed. Lifelong learning is a component of the practice-based learning competency. A portfolio is one way to assess practice-based learning, but its use is unfamiliar to most surgical programs. The authors describe the evolution of the Surgical Learning and Instructional Portfolio (SLIP) into a worthwhile educational tool. METHODS: In March 2001, the authors began a program to encourage residents to develop a case-based portfolio to document their experience and demonstrate acquisition of knowledge in caring for a variety of surgical diseases. The monthly case topic was chosen by the resident and reported using a template: case history, supporting diagnostic studies, differential diagnosis, final diagnosis with ICD-9 coding, management options, treatment used, 3 lessons learned, embellishment of 1 lesson, and 2 articles supporting the experience. Initially, cases were submitted to the program coordinator and reviewed every 6 months with a faculty advisor to provide feedback. RESULTS: After the first 18 months of this program, resident compliance was less than 50%, satisfaction was low, and formal review did not occur. In July 2004, a single faculty member became responsible for evaluating and providing feedback on the monthly SLIPs. The assignments were handled electronically with feedback delivered within the month via e-mail. SLIP quality as measured by resident compliance and satisfaction improved. CONCLUSION: These SLIPs have matured into a valuable educational tool satisfying multiple ACGME competencies. This portfolio system required direct faculty feedback to become successful.

A PGY1 curriculum--meeting a need for changing times.

A systematic process is described that produced a PGY1 curriculum for the surgical residents at Medical College of Wisconsin. The process involved faculty and residents. Topics were selected based on the six general competencies. Objectives were developed for all topics. The curriculum was delivered to the residents while they were off clinical duty. This Protected Block Curriculum approach was chosen to facilitate the learning structure of the curriculum. Feedback was positive, learning objectives appeared to be achieved and the plan is to continue to develop the PGY1 curriculum in the same format.

Role of the Open Abdomen in Critically Ill Patients.

An open abdomen is common used in critically ill patients to temporize permanent abdominal closure. The most common reason for leaving the abdomen open by reopening a laparotomy, not closing, or creating a fresh laparotomy is the abdominal compartment syndrome. The open abdomen technique is also used in damage control operations and intra-abdominal sepsis. Negative pressure wound therapy may be associated with better outcomes than other temporary abdominal closure techniques. The open abdomen is associated with many early and late complications, including infections, gastrointestinal fistulas, and ventral hernias. Clinicians should be vigilant regarding the development of these complications.

Predicting academic performance in surgical training.

INTRODUCTION: During surgical residency, trainees are expected to master all the 6 competencies specified by the ACGME. Surgical training programs are also evaluated, in part, by the residency review committee based on the percentage of graduates of the program who successfully complete the qualifying examination and the certification examination of the American Board of Surgery in the first attempt. Many program directors (PDs) use the American Board of Surgery In-Training Examination (ABSITE) as an indicator of future performance on the qualifying examination. Failure to meet an individual program's standard may result in remediation or a delay in promotion to the next level of training. Remediation is expensive in terms of not only dollars but also resources, faculty time, and potential program disruptions. We embarked on an exploratory study to determine if residents who might be at risk for substandard performance on the ABSITE could be identified based on the individual resident's behavior and motivational characteristics. If such were possible, then PDs would have the opportunity to be proactive in developing a curriculum tailored to an individual resident, providing a greater opportunity for success in meeting the program's standards. METHODS: Overall, 7 surgical training programs agreed to participate in this initial study and residents were recruited to voluntarily participate. Each participant completed an online assessment that characterizes an individual's behavioral style, motivators, and Acumen Index. Residents completed the assessment using a code name assigned by each individual PD or their designee. Assessments and the residents' 2013 ABSITE scores were forwarded for analysis using only the code name, thus insuring anonymity. Residents were grouped into those who took the junior examination, senior examination, and pass/fail categories. A passing score of ≥70% correct was chosen a priori. Correlations were performed using logistic regression and data were also entered into a neural network (NN) to develop a model that would explain performance based on data obtained from the TriMetrix assessments. RESULTS: A total of 117 residents' TriMetrix and ABSITE scores were available for analysis. They were divided into 2 groups of 64 senior residents and 53 junior residents. For each group, the pass/fail criteria for the ABSITE were set at 70 and greater as passing and 69 and lower as failing. Multiple logistic regression analysis was complete for pass/fail vs the TriMetrix assessments. For the senior data group, it was found that the parameter Theoretical correlates with pass rate (p < 0.043, B = -0.513, exp(B) = 0.599), which means increasing theoretical scores yields a decreasing likelihood of passing in the examination. For the junior data, the parameter Internal Role Awareness correlated with pass/fail rate (p < 0.004, B = 0.66, exp(B) = 1.935), which means that an increasing Internal Role Awareness score increases the likelihood of a passing score. The NN was able to be trained to predict ABSITE performance with surprising accuracy for both junior and senior residents. CONCLUSION: Behavioral, motivational, and acumen characteristics can be useful to identify residents "at risk" for substandard performance on the ABSITE. Armed with this information, PDs have the opportunity to intervene proactively to offer these residents a greater chance for success. The NN was capable of developing a model that explained performance on the examination for both the junior and the senior examinations. Subsequent testing is needed to determine if the NN is a good predictive tool for performance on this examination.

Activity of antibacterial impregnated central venous catheters against Klebsiella pneumoniae.

OBJECTIVE: Antibiotically coated or impregnated catheters are effective in eliminating gram-positive bacteria from their surfaces. However, their activity against gram-negative bacteria is not well known. The aim of this study was to evaluate and compare the adherence, persistence and colonization of Klebsiella pneumoniae on catheter surfaces and also to assess bacteriostatic and bactericidal levels. DESIGN: Randomized, controlled, laboratory study. SETTING: University surgical microbiology laboratory. SUBJECTIVE: Silver sulfadiazine-chlorhexidine impregnated (SSC), minocycline and rifampin bonded (M+R), silver, platinum and carbon incorporated (SP+C) and non-antiseptic central venous catheter segments. INTERVENTIONS: Catheter segments were immersed in 1 ml of phosphate buffered saline (0.01 mol/l) with 0.25% dextrose (PBSD) and incubated at 37 degrees C. The PBSD was replaced daily. Effluents were frozen at -70 degrees C for subsequent determination of bacteriostatic and bactericidal activity. On days 1,3,7,14 and 21 after initial immersion, 1 ml standardized inoculum of Klebsiella pneumoniae was added to 90 tubes for a period of 30 min. The inoculum was then replaced with PBSD. One third of the samples were immediately sonicated and plated for the determination of bacterial adherence. The remaining segments were incubated for 4 and 24 h, followed by the same procedure to determine bacterial persistence and colonization with time. All plates were read after 24 h of incubation. MEASUREMENTS AND RESULTS: There was a significant reduction in initial bacterial adherence for SP+C catheters on all days ( p<0.05). SSC catheters prevented initial bacterial adherence for the first 7 days only ( p<0.05). SSC and SP+C catheters prevented bacterial persistence and further colonization on all days. However M+R catheters prevented bacterial colonization for 3 days only. Effluent studies indicated that the impregnated agents in catheter SSC were bactericidal compared to catheter M+R, which were bacteriostatic to K. pneumoniae. No antibacterial activity was detected in the effluents from catheter SP+C. CONCLUSIONS: SSC and SP+C catheters are effective in eliminating K. pneumoniae from their surfaces for at least 21 days. M+R catheters are less effective in eliminating bacterial adherence and colonization may be due to their bacteriostatic property.