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Biomedical subjects

D C Classen

Publications and source records attributed to D C Classen.

At least 19 recordsLinked to original sources
PubMed1999

Treatment of infected left ventricular assist device using antibiotic-impregnated beads.

There is no well-established therapy for treating infections of heart-assist or artificial heart devices, a serious problem with life-threatening consequences. We used a promising new approach in which antibiotic-impregnated polymethylmethacrylate beads were placed around an implanted left ventricular assist device to control an external blood pump infection in a bridge-to-transplant patient. In this case report, we describe the potential of antimicrobial-impregnated polymethylmethacrylate beads for in situ control of infections involving external surfaces of cardiovascular devices.

Combined Modality Therapy↗
PubMed1999

Clinical and financial impact of intravenous erythromycin therapy in hospitalized patients.

OBJECTIVE: To determine the economic consequences of intravenous erythromycin use in hospital patients in a variety of clinical circumstances. DESIGN: Retrospective cohort study of patients with specified primary diagnosis-related group discharge diagnoses treated from January 1, 1990, to December 31, 1994, who received erythromycin, and a matched cohort group from the same period who did not receive erythromycin. SETTING: LDS Hospital, Salt Lake City, UT, a 520-bed teaching hospital. PATIENTS: A long-term archive of clinical and financial data from a computerized hospital information system was searched for patients meeting a strict case definition. This archive contained information on erythromycin exposure as well as concurrent drug therapy and adverse drug events that had been prospectively evaluated during hospitalization throughout the study and cohort periods. Detailed costs were available for each patient. MAIN OUTCOME MEASURE: Attributable differences in lengths of stay and total costs determined using linear regression modeling. RESULTS: For 797 erythromycin patients and 2771 cohort patients, we found an attributable increased length of stay of 2.14 days and an increased cost of hospitalization of $6061 for erythromycin case patients. Case patients also had a significantly increased risk of adverse drug events. Linear regression modeling showed that erythromycin use was significantly related to increased length of stay and cost of hospitalization. CONCLUSIONS: Intravenous erythromycin use has been associated with significant increases in hospital length of stay and total hospital cost.

Adolescent↗
PubMed1999

Evaluation of a computer-assisted antibiotic-dose monitor.

OBJECTIVE: To examine the effect of a computer-assisted antibiotic-dose monitor used to reduce the number of days that patients receive excessive dosages of antibiotics and the number of adverse drug events (ADEs) secondary to antibiotics. DESIGN: Descriptive epidemiologic study of a two-year preintervention period and one-year intervention period. SETTING: The LDS Hospital, a tertiary care center in Salt Lake City, UT. PATIENTS: All patients aged > or = 18 years, admitted to LDS Hospital from April 1, 1993, to March 31, 1996, who received at least one of five targeted antibiotics (vancomycin, gentamicin, imipenem, cefazolin, cefuroxime), who had a serum creatinine or a urine creatinine clearance test result before antibiotic therapy, and who were never admitted or transferred to the shock/trauma/respiratory intensive care unit. METHODS: Each morning during the 12-month intervention period, the antibiotic-dose monitor checked the renal function of all patients who were receiving any of the five antibiotics. Pharmacists received a computer listing of patients who may have been receiving excessive dosages. The antibiotic-dose monitor suggested an alternate dosage and a pharmacist contacted the patient's physician if the suggested change in the dosage was appropriate. RESULTS: During the intervention period, 4483 patients received at least one of the five study antibiotics and 1974 (44%) were identified as receiving an excessive dosage, compared with 4494 (50%) of 8901 patients during the preintervention period (p < 0.001). The patients receiving excessive dosages received an excessive dosage for an average of 2.9 days during the intervention period, compared with 4.7 days (p < 0.001) during the preintervention period. In addition, these same patients during the intervention period received fewer doses of antibiotics (10.9 vs. 13.4; p < 0.001), fewer grams of antibiotics (10.4 vs. 12.0; p < 0.02), at less cost ($98 vs. $128; p < 0.004) than the patients during the preintervention period. Moreover, there were 14 ADEs (0.3%) secondary to the five study antibiotics during the intervention period, compared with 82 (0.9%; p < 0.001) for the two-year preintervention period. The study also found that significantly more patients identified as receiving excessive dosages had experienced decreases in renal function, compared with patients who were not identified as receiving excessive dosages (25% vs. 12% during preintervention period and 23% vs. 16% during intervention period; p < 0.001). CONCLUSIONS: Many patients experience decreases in renal function after antibiotics are ordered. The use of the computer-assisted antibiotic-dose monitor appears to be a promising method to help reduce the excessive use and cost of antibiotic therapy and reduce the number of ADEs secondary to antibiotics.

Adverse Drug Reaction Reporting Systems↗
PubMed1999

Immunization in the first month of life may explain decline in incidence of IDDM in The Netherlands.

A low cumulative incidence of IDDM was reported in Dutch males born in 1962 (Diabetologia 1992: 35: 139-142) compared to males born in previous or later years. The cause for the decreased risk has not been previously explained. We propose that children born in 1962 during an European smallpox epidemic may have received the smallpox vaccine in the first month of life and this may have attributed to the decreased risk of IDDM in these children. We have shown that immunization with several different vaccines starting in the first month of life prevents diabetes in NOD mice and BB rats (Autoimmunity 1996: 24: 137-145) while immunization at birth with the BCG vaccine is associated with an decreased risk of IDDM in humans (Infectious Diseases in Clinical Practice 1997: 6: 449-454). An even bigger decline in diabetes is seen in rodents and associated in humans when one compares immunization starting in the first month of life to immunization starting after 2 months, since the later has been associated with an increased risk of IDDM. Immunization studies in the past have typically followed patients for only several weeks to determine any unplanned affects on autoimmune disease. Due to the potential benefit of reducing the incidence of diabetes by 50% through age 18 we believe clinical trials are warranted to study the effect of timing of immunization on IDDM.

Adolescent↗
PubMed1998

A computer-assisted management program for antibiotics and other antiinfective agents.

BACKGROUND AND METHODS: Optimal decisions about the use of antibiotics and other antiinfective agents in critically ill patients require access to a large amount of complex information. We have developed a computerized decision-support program linked to computer-based patient records that can assist physicians in the use of antiinfective agents and improve the quality of care. This program presents epidemiologic information, along with detailed recommendations and warnings. The program recommends antiinfective regimens and courses of therapy for particular patients and provides immediate feedback. We prospectively studied the use of the computerized antiinfectives-management program for one year in a 12-bed intensive care unit. RESULTS: During the intervention period, all 545 patients admitted were cared for with the aid of the antiinfectives-management program. Measures of processes and outcomes were compared with those for the 1136 patients admitted to the same unit during the two years before the intervention period. The use of the program led to significant reductions in orders for drugs to which the patients had reported allergies (35, vs. 146 during the preintervention period; P<0.01), excess drug dosages (87 vs. 405, P<0.01), and antibiotic-susceptibility mismatches (12 vs. 206, P<0.01). There were also marked reductions in the mean number of days of excessive drug dosage (2.7 vs. 5.9, P<0.002) and in adverse events caused by antiinfective agents (4 vs. 28, P<0.02). In analyses of patients who received antiinfective agents, those treated during the intervention period who always received the regimens recommended by the computer program (n=203) had significant reductions, as compared with those who did not always receive the recommended regimens (n= 195) and those in the preintervention cohort (n = 766), in the cost of antiinfective agents (adjusted mean, $102 vs. $427 and $340, respectively; P<0.001), in total hospital costs (adjusted mean, $26,315 vs. $44,865 and $35,283; P<0.001), and in the length of the hospital stay days (adjusted mean, 10.0 vs. 16.7 and 12.9; P<0.001). CONCLUSIONS; A computerized antiinfectives-management program can improve the quality of patient care and reduce costs.

Anti-Bacterial Agents↗
PubMed1998

Oral antimicrobial prophylaxis in bone marrow transplant recipients: randomized trial of ciprofloxacin versus ciprofloxacin-vancomycin.

The optimal oral antimicrobial prophylactic regimen for bone marrow transplant recipients remains to be elucidated. We randomized 84 patients to receive either oral ciprofloxacin or ciprofloxacin plus vancomycin at hospital admission. Patients were monitored for bacteremias and clinical parameters, and stool and throat swab surveillance cultures were performed. The addition of vancomycin resulted in a significant decrease in the frequency of patients with surveillance cultures positive for coagulase-negative staphylococci (stool cultures, 44 versus 23%; throat swab cultures, 37 versus 19%) and alpha-hemolytic streptococci (throat swab cultures, 90 versus 60%). The frequencies of positivity for Candida spp. and gram-negative organisms on surveillance cultures were comparable. Despite these results, no differences in the incidences of bacteremias (12 of 41 versus 12 of 43 patients) or clinical parameters such as number of days to first fever, total number of febrile days, length of stay, and number of transfusions could be demonstrated. Because of a lack of efficacy of vancomycin and emerging problems with vancomycin-resistant isolates, vancomycin should not be used in oral antimicrobial prophylaxis regimens.

Antibiotic Prophylaxis↗
PubMed1998

Association of borderline oxacillin-susceptible strains of Staphylococcus aureus with surgical wound infections.

Staphylococcus aureus isolates which produce type A staphylococcal beta-lactamase have been associated with wound infections complicating the use of cefazolin prophylaxis in surgery. To further evaluate this finding, 215 wound isolates from 14 cities in the United States were characterized by antimicrobial susceptibility and beta-lactamase type and correlated with the preoperative prophylactic regimen. Borderline-susceptible S. aureus isolates of phage group 5 (BSSA-5), which produce large amounts of type A beta-lactamase and exhibit borderline susceptibility to oxacillin, comprised a greater percentage of the 120 wound isolates associated with cefazolin prophylaxis than they did of the 95 isolates associated with other prophylactic regimens (25% versus 12.6%, respectively; P < 0.05). In contrast, methicillin-resistant S. aureus isolates were distributed evenly between the two groups (8.3% versus 11.6%, respectively). In vitro assays demonstrated that cefazolin was hydrolyzed faster by BSSA-5 strains than by other beta-lactamase-producing, methicillin-susceptible strains (1.54 versus 0.50 microg/min/10(8) CFU, respectively; P < 0.0001). These data demonstrate that BSSA-5 strains are a distinct subpopulation of methicillin-susceptible S. aureus which frequently cause deep surgical wound infections. Cefazolin use in prophylaxis is a risk factor for BSSA-5 infection.

Cefazolin↗
PubMed1997

Infectious diseases consultation: impact on outcomes for hospitalized patients and results of a preliminary study.

In the absence of detailed and specific data on outcomes, specialists are thought to contribute excessively to the cost of care. Infectious diseases physicians are at further risk of heavy utilization of medical resources because their patients often are those with serious complications or expensive underlying diseases (e.g., AIDS). By using readily available information in a sophisticated computer database, we examined the crude economic impact of an inpatient infectious diseases consultation and identified important matching variables for more refined analysis. The study was performed at LDS Hospital (Salt Lake City), a tertiary care facility with four full-time infectious diseases physicians. A total of 496 cases (patients who were seen by an infectious diseases consultant) were matched with 3,117 controls (patients who were not seen by an infectious diseases consultant). Matching was performed on the basis of age, sex, exact discharge diagnosis-related group, minimum length of hospital stay equal to the interval from admission to consultation for cases, and measures of the severity of illness (nursing acuity score and the number of secondary diagnoses). Cases had longer lengths of hospital stays, longer intensive care unit lengths of stays, and higher antibiotic costs than did matched controls, and if the consultation occurred in the last one-third of hospitalization, cases had shorter lengths of hospital stay and lower antibiotic costs than did controls.

Case-Control Studies↗
PubMed1996

Implementing antibiotic practice guidelines through computer-assisted decision support: clinical and financial outcomes.

OBJECTIVE: To determine the clinical and financial outcomes of antibiotic practice guidelines implemented through computer-assisted decision support. DESIGN: Descriptive epidemiologic study and financial analysis. SETTING: 520-bed community teaching hospital in Salt Lake City, Utah. PATIENTS: All 162 196 patients discharged from LDS Hospital between 1 January 1988 and 31 December 1994. INTERVENTION: An antibiotic management program that used local clinician-derived consensus guidelines embedded in computer-assisted decision support programs. Prescribing guidelines were developed for inpatient prophylactic, empiric, and therapeutic uses of antibiotics. MEASUREMENTS: Measures of antibiotic use included timing of preoperative antibiotic administration and duration of postoperative antibiotic use. Clinical outcomes included rates of adverse drug events, patterns of antimicrobial resistance, mortality, and length of hospital stay. Financial and use outcomes were expressed as yearly expenditures for antibiotics and defined daily doses per 100 occupied bed-days. RESULTS: During the 7-year study period, 63 759 hospitalized patients (39.3%) received antibiotics. The proportion of the hospitalized patients who received antibiotics increased each year, from 31.8% in 1988 to 53.1% in 1994. Use of broad-spectrum antibiotics increased from 24% of all antibiotic use in 1988 to 47% in 1994. The annual Medicare case-mix index increased from 1.7481 in 1988 to 2.0520 in 1993. Total acquisition costs of antibiotics (adjusted for inflation) decreased from 24.8% ($987,547) of the pharmacy drug expenditure budget in 1988 to 12.9% ($612,500) in 1994. Antibiotic costs per treated patient (adjusted for inflation) decreased from $122.66 per patient in 1988 to $51.90 per patient in 1994. Analysis using a standardized method (defined daily doses) to compare antibiotic use showed that antibiotic use decreased by 22.8% overall. Measures of antibiotic use and clinical outcomes improved during the study period. The percentage of patients having surgery who received appropriately timed preoperative antibiotics increased from 40% in 1988 to 99.1% in 1994. The average number of antibiotic doses administered for surgical prophylaxis was reduced from 19 doses in the base year to 5.3 doses in 1994. Antibiotic-associated adverse drug events decreased by 30%. During the study, antimicrobial resistance patterns were stable, and length of stay remained the same. Mortality rates decreased from 3.65% in 1988 to 2.65% in 1994 (P < 0.001). CONCLUSIONS: Computer-assisted decision support programs that use local clinician-derived practice guidelines can improve antibiotic use, reduce associated costs, and stabilize the emergence of antibiotic-resistant pathogens.

Anti-Bacterial Agents↗
PubMed1995

A large randomized clinical trial of a silver-impregnated urinary catheter: lack of efficacy and staphylococcal superinfection.

PURPOSE: The antibacterial activity of silver-containing compounds has recently been employed in constructing medical devices, such as vascular and urinary catheters, that may be effective in blocking infection. The present study was designed to evaluate the efficacy of a silver oxide-coated urinary catheter. PATIENTS AND METHODS: A total of 1,309 hospitalized patients who required placement of an indwelling urinary catheter for 24 hours or longer were randomly assigned to receive either a silicone catheter coated externally with 5% silver oxide or a standard silicone elastomer-coated latex catheter. Daily catheter-urine specimens were collected aseptically and catheter-care violations were monitored daily for the duration of the catheterization. RESULTS: Bacteriuria developed in 85 of 745 patients (11.4%) in the silver-coated catheter group and in 73 of 564 patients (12.9%) in the control group (P = 0.45). In women who did not receive antibiotics, the rates were 29.3% and 30.4%, respectively (P = 0.98). In men who did not receive antibiotics, the rate of bacteriuria was significantly higher with the silver-coated catheter (29.4% compared to 8.3%, respectively, P = 0.02). Staphylococcal species were isolated more often from the silver-coated catheter group than from the control group (25% versus 8% of all isolates, respectively, P = 0.002). CONCLUSIONS: This study, the largest ever reported evaluating any silver-impregnated device, has not only failed to demonstrate the efficacy of silver in prevention of catheter-associated bacteriuria, as suggested in prior studies, but it has also shown a significantly increased incidence of bacteriuria in male patients and a significantly increased occurrence of staphylococcal bacteriuria. These results suggest the need for caution and for similar large-scale trials before silver-containing compounds are widely used for preventing device-associated infections, both in vascular and urinary catheters.

Bacteriuria↗