Biomedical subjects

D C Classen

Publications and source records attributed to D C Classen.

At least 37 records · Page 2Linked to original sources

PubMed1993

Prospective surveillance of imipenem/cilastatin use and associated seizures using a hospital information system.

OBJECTIVE: To develop computerized methods to monitor and recommend dosage changes for patients treated with excessive dosages of imipenem/cilastatin (I/C) and to determine the incidence of I/C-associated seizures in our patient population. DESIGN: Prospective observational and interventional study of all patients admitted to LDS Hospital and treated with I/C from May 1, 1987, through June 30, 1991. SETTING: LDS Hospital, Salt Lake City, UT, a 520-bed, tertiary care center associated with the University of Utah School of Medicine. PATIENTS: Using a hospital information system we developed computerized algorithms to identify and monitor patients receiving I/C. These algorithms screened the computer-stored medical records of all inpatient admissions for I/C prescription orders. Computer-decision support algorithms estimated the renal function of each I/C-treated patient and provided suggestions when dosages were determined to be excessive. Additional computer-generated alerts identified patients who were receiving anticonvulsants concomitantly with I/C or whose therapy reflected dosage changes in the previous 24 hours. A list of all I/C-treated patients with alerts was reviewed daily by a clinical pharmacist and prescribing physicians were contacted if the computer-generated suggestions were clinically relevant. MAIN OUTCOME MEASURE: The number and characterization of I/C-associated seizures. RESULTS: From May 1, 1987, through June 30, 1991, we prospectively monitored 107,600 patients of whom 1951 were treated with I/C. The following risk factors for I/C-associated seizures were observed in the I/C-treated population: CNS disease (6 percent), seizure disorders (0.6 percent), and abnormal renal function (70 percent). The observational and interventional methods employed in this study resulted in 79 percent of the patients receiving I/C dosages appropriate for their corresponding renal function. During the 50-month study period, we detected four seizures (0.20 percent) in the I/C-treated patients. All 4 patients were receiving I/C dosages that were excessive with respect to their renal function. CONCLUSIONS: Our rate of seizure (0.2 percent) was lower than the 1-2 percent rate reported in the literature despite the fact that more than 70 percent of the patients who received I/C had risk factors for seizure. We believe that appropriate dosing of I/C results in a low rate of associated seizures. Computer-assisted monitoring of I/C dosages in relation to renal function resulted in a reduced incidence of seizures.

Adolescent↗

PubMed1993

Using a hospital information system to assess the effects of adverse drug events.

The most common adverse events experienced by hospitalized patients are drug related. While numerous studies have described the incidence and types of adverse drug events (ADEs), the actual effect of these events on patient outcomes have only been estimated. The studies that have described the effects of ADEs on patient outcomes have not stratified patients by severity of illness and hospital costs were estimated based on a percent of hospital charges. We designed a study to utilize the resources of our hospital information system to assess the attributable effects of ADEs on hospital length of stay and cost of hospitalization. This approach emphasized the difference between study patients and their matched control patients rather than overall differences between patients with and without ADEs. In addition, we used nursing acuity data to help adjust severity of illness within DRG groups and actual hospital costs were used instead of estimated costs. This study found that while the average length of stay for patients with ADEs was 8.19 days compared to 4.36 days for matched control patients, the attributable difference due to the ADEs was 1.94 days. Similar methods found that patients with ADEs had an average cost of hospitalization of $10,584 compared to $5,350 for those without and the attributable difference due to ADEs was $1,939. This indicates that the 569 ADEs at our hospital during 1992 resulted in an additional 1,104 extra patient days at a cost of $1,103,291.

Adverse Drug Reaction Reporting Systems↗

PubMed1992

The timing of prophylactic administration of antibiotics and the risk of surgical-wound infection.

BACKGROUND: Randomized, controlled trials have shown that prophylactic antibiotics are effective in preventing surgical-wound infections. However, it is uncertain how the timing of antibiotic administration affects the risk of surgical-wound infection in actual clinical practice. METHODS: We prospectively monitored the timing of antibiotic prophylaxis and studied the occurrence of surgical-wound infections in 2847 patients undergoing elective clean or "clean-contaminated" surgical procedures at a large community hospital. The administration of antibiotics 2 to 24 hours before the surgical incision was defined as early; that during the 2 hours before the incision, as preoperative; that during the 3 hours after the incision, as perioperative; and that more than 3 but less than 24 hours after the incision, as postoperative. RESULTS: Of the 1708 patients who received the prophylactic antibiotics preoperatively, 10 (0.6 percent) subsequently had surgical-wound infections. Of the 282 patients who received the antibiotics perioperatively, 4 (1.4 percent) had such infections (P = 0.12; relative risk as compared with the preoperatively treated group, 2.4; 95 percent confidence interval, 0.9 to 7.9). Of 488 patients who received the antibiotics postoperatively, 16 (3.3 percent) had wound infections (P less than 0.0001; relative risk, 5.8; 95 percent confidence interval, 2.6 to 12.3). Finally, of 369 patients who had antibiotics administered early, 14 (3.8 percent) had wound infections (P less than 0.0001; relative risk, 6.7; 95 percent confidence interval, 2.9 to 14.7). Stepwise logistic-regression analysis confirmed that the administration of antibiotics in the preoperative period was associated with the lowest risk of surgical-wound infection. CONCLUSIONS: We conclude that in surgical practice there is considerable variation in the timing of prophylactic administration of antibiotics and that administration in the two hours before surgery reduces the risk of wound infection.

Adult↗

PubMed1992

Computerized identification of patients at high risk for hospital-acquired infection.

Surveillance for hospital-acquired infections is required in U.S. hospitals, and statistical methods have been used to predict the risk of infection. We used the HELP (Health Evaluation through Logical Processing) Hospital Information System at LDS Hospital to develop computerized methods to identify and verify hospital-acquired infections. The criteria for hospital-acquired infection are standardized and based on the guidelines of the Study of the Efficacy of Nosocomial Infection Control and the Centers for Disease Control. The computer algorithms are automatically activated when key items of information, such as microbiology results, are reported. Computer surveillance identified more hospital-acquired infections than did traditional methods and has replaced manual surveillance in our 520-bed hospital. Data on verified hospital-acquired infections are electronically transferred to a microcomputer to facilitate outbreak investigation and the generation of reports on infection rates. Recently, we used the HELP system to employ statistical methods to automatically identify high-risk patients. Patient data from more than 6000 patients were used to develop a high-risk equation. Stepwise logistic regression identified 10 risk factors for nosocomial infection. The HELP system now uses this logistic-regression equation to monitor and determine the risk status for all hospitalized patients each day. The computer notifies infection control practitioners each morning of patients who are newly classified as being at high risk. Of 605 hospital-acquired infections during a 6-month period, 472 (78%) occurred in high-risk patients, and 380 (63%) were predicted before the onset of infection. Computerized regression equations to identify patients at risk of having hospital-acquired infections can help focus prevention efforts.

Cross Infection↗

PubMed1992

Randomized trial of meatal care with silver sulfadiazine cream for the prevention of catheter-associated bacteriuria.

A randomized, controlled, prospective clinical trial involving 696 hospitalized patients was undertaken to determine the effectiveness of 1% silver sulfadiazine cream applied twice daily to the urethral meatus in preventing transurethral catheter-associated bacteriuria. The overall incidence of bacteriuria was 11.4% (38/332) in the treated group and 13.2% (48/364) in the untreated group (P = .56; odds ratio, 0.85; 95% confidence interval, 0.53-1.37). Cox proportional hazards analysis identified female sex, lack of antibiotic use, and a positive initial meatal culture (but not treatment randomization or lack of urinemeter use) as independent variables associated with an increased risk of bacteriuria. Survival curve analysis of subgroups stratified by sex and antibiotic use failed to detect an effect of silver sulfadiazine on the rate of bacteriuria. Meatal care with silver sulfadiazine cream did not prevent the development of catheter-associated bacteriuria in short-term catheterized patients.

Administration, Topical↗

PubMed1992

Description of a computerized adverse drug event monitor using a hospital information system.

To improve the detection and characterization of adverse drug events (ADEs) in hospitalized patients, a computerized adverse drug event monitor was developed. Computer programs were written to allow for voluntary as well as automated detection of adverse drug events using the HELP hospital information system, a large integrated hospital database containing computerized patient medical records and a knowledge base allowing for automated medical decisions. Programs were created to allow simple computer entry of potential adverse drug events by physicians, pharmacists, and nurses. Automated detection of potential adverse drug events relied on signals such as sudden medication stop orders, "antidote" orders, and selected abnormal laboratory values. Each day a list of all potential adverse drug events from these sources was generated and a pharmacist reviewed the medical records and interviewed healthcare personnel associated with patients identified as having potential adverse drug events. This process allowed for characterization of the event, causality assessment, and follow-up of the resulting clinical course by the pharmacist. The permanent storage of these results in the computerized patient medical record permits their future retrieval to prevent adverse drug events during subsequent hospital care. The authors conclude that fully integrated hospital systems will permit the further development and evaluation of computer-assisted methods for the detection of adverse drug events in hospitalized patients.

Adverse Drug Reaction Reporting Systems↗

PubMed1992

Prevention of adverse drug events through computerized surveillance.

Adverse drug events (ADEs) are a serious health problem and are the leading adverse event experienced by hospitalized patients. Numerous hospitals have used different methods to improve the reporting of ADEs but few have undertaken studies aimed at the prevention of ADEs. We found that computerized ADE surveillance identified significantly more ADEs than our previous voluntary reporting method. Moreover, the computerized ADE surveillance system created a database of ADEs which allowed us to analyze the ADEs and design methods for prevention. We found that computer alerts of previously known drug allergies generated when drugs were ordered significantly reduced the number of type B ADEs, 56 vs 8 (p < 0.001). In addition, we found that the timely surveillance of ADEs combined with physician notification reduced the number of severe ADEs, 41 vs 12 (p < 0.001). Initial analysis of the ADE database has shown that on average patients with type B ADEs are hospitalized longer (17 vs 14 days) and have larger hospitalization costs ($30,617 vs $23,256) than patients with type A ADEs. Patients with severe ADEs also are hospitalized longer (20 vs 13 days) and have larger hospitalization costs ($38,007 vs $22,474) than patients with moderate ADEs. This indicates that the prevention and early treatment of ADEs can reduce the length of hospitalization and result in a considerable cost savings to the hospital.

Clinical Pharmacy Information Systems↗

PubMed1992

Clinical trial of junction seals for the prevention of urinary catheter-associated bacteriuria.

BACKGROUND: Preconnected catheter systems with sealed junctions have been associated with reduced rates of bacteriuria and mortality. A clinical trial was undertaken to evaluate the effectiveness of a junction seal applied after catheter insertion for preventing bacteriuria and reducing mortality. METHODS: Patients undergoing transurethral catheterization at a community hospital were randomized within 24 hours of catheter insertion to receive either a tape seal applied to the catheter-drainage tubing junction or no tape seal. Catheter urine cultures and catheter care violations were monitored daily until catheter removal or patient discharge. RESULTS: Overall, 124 (13.7%) of 903 patients in the group receiving a junction seal acquired bacteriuria, compared with 125 (14.9%) of 837 patients in the control group (P = .52, odds ratio = 0.91, 95% confidence interval, 0.69 to 1.20). Multivariate analysis revealed that only female gender and lack of systemic antibiotic use independently correlated with the development of bacteriuria; neither junction treatment randomization nor disconnection of the junction was associated with bacteriuria. Survival curve analysis of patients stratified by gender and antibiotic use revealed no significant differences in the rate of bacteriuria between treatment groups. The overall mortality in the tape seal group was less than that in the control group (6.6% vs. 8.0%, respectively), but not to a statistically significant extent despite stratification by antibiotic use. CONCLUSIONS: The use of a tape seal applied to the catheter-drainage tubing junction within 24 hours of catheter insertion was not associated with significantly lower rates of bacteriuria and mortality in patients undergoing short-term catheterization.

Bacteriuria↗

PubMed1992

Intensive surveillance of midazolam use in hospitalized patients and the occurrence of cardiorespiratory arrest.

Midazolam, a benzodiazepine used extensively as a sedative and a hypnotic for patients undergoing inpatient and outpatient medical procedures, has been associated with several side effects, the most serious of which are cardiac and respiratory arrest. We studied the use of midazolam and its association with cardiac and respiratory arrest among hospital patients at our institution. From 1988 through 1990 we identified 5439 patients exposed to midazolam, representing 8% of all patients admitted; 3031 (55.7%) received midazolam while not on mechanical ventilation. In the majority of patients the drug was given as a one-time dose, and the total dose was less than or equal to 5 mg in more than 70%. Three patients (0.099%) experienced respiratory arrest. All three events occurred within 2 hours after the last dose of midazolam had been given. All patients were elderly and all survived. The rate of respiratory arrest appears low at our institution and was associated with high doses of midazolam, concurrent use of opiates, and use in elderly patients.

Aged↗

PubMed1991

Computerized surveillance of adverse drug events in hospital patients.

OBJECTIVE: To develop a new method to improve the detection and characterization of adverse drug events (ADEs) in hospital patients. DESIGN: Prospective study of all patients admitted to our hospital over an 18-month period. SETTING: LDS Hospital, Salt Lake City, Utah, a 520-bed tertiary care center affiliated with the University of Utah School of Medicine, Salt Lake City. PATIENTS: We developed a computerized ADE monitor, and computer programs were written using an integrated hospital information system to allow for multiple source detection of potential ADEs occurring in hospital patients. Signals of potential ADEs, both voluntary and automated, included sudden medication stop orders, antidote ordering, and certain abnormal laboratory values. Each day, a list of all potential ADEs from these sources was generated, and a pharmacist reviewed the medical records of all patients with possible ADEs for accuracy and causality. Verified ADEs were characterized as mild, moderate, or severe and as type A (dose-dependent or predictable) or type B (idiosyncratic or allergic) reactions, and causality was further measured using a standardized scoring method. OUTCOME MEASURE: The number and characterization of ADEs detected. RESULTS: Over 18 months, we monitored 36,653 hospitalized patients. There were 731 verified ADEs identified in 648 patients, 701 ADEs were characterized as moderate or severe, and 664 were classified as type A reactions. During this same period, only nine ADEs were identified using traditional detection methods. Physicians, pharmacists, and nurses voluntarily reported 92 of the 731 ADEs detected using this automated system. The other 631 ADEs were detected from automated signals, the most common of which were diphenhydramine hydrochloride and naloxone hydrochloride use, high serum drug levels, leukopenia, and the use of phytonadione and antidiarrheals. The most common symptoms and signs were pruritus, nausea and/or vomiting, rash, and confusion-lethargy. The most common drug classes involved were analgesics, anti-infectives, and cardiovascular agents. CONCLUSION: We believe that screening for ADEs with a computerized hospital information system offers a potential method for improving the detection and characterization of these events in hospital patients.

Adolescent↗

PubMed1991

The HELP system and its application to infection control.

The HELP system is a comprehensive hospital information system that is linked to an allied financial data base. The clinical data base integrates information from areas such as admitting, pharmacy, radiology, surgery, pathology, nursing, respiratory therapy, and the clinical laboratories, including microbiology. This allows for the creation of an electronic medical record that contains all the clinical and financial data for each patient. The HELP system combines both communication and advice features through the use of data- and time-driven algorithms. We have used the HELP system to automate the surveillance and analysis of hospital-acquired infections and to identify patients at high risk for nosocomial infection. The expert system features have also been used to suggest alternatives for patients receiving inappropriate antimicrobial therapy, to improve the timing of antibiotic prophylaxis in surgery, and to curtail unnecessarily prolonged prophylaxis. Automated hospital information systems such as HELP can facilitate the investigation of a broad range of infection control, quality improvement, and cost-containment issues.

Cross Infection↗

PubMed1991

Prevention of catheter-associated bacteriuria: clinical trial of methods to block three known pathways of infection.

The simultaneous use of methods to block all three known pathways of bacterial entry into the bladders of catheterized patients has been suggested because of the limited effectiveness of individual methods that block single pathways. We conducted a randomized controlled trial to assess the prevention of bacteriuria in patients, using a three-way system that included a hydrophilic polymer-coated and preconnected sealed catheter system, daily catheter care, and disinfection of the outflow tube of the drainage bag with povidone-iodine (i.e., methods to block bacterial entry at the urethral insertion site, at the catheter drainage tube junction, and at the outflow tube). Among treated patients, 14 (4.7%) of 300 acquired bacteriuria as compared with 15 (4.9%) of 306 who did not receive the protocol treatments. Only 3 of 29 episodes of bacteriuria occurred in patients whose meatal cultures did not contain gram-negative bacilli or enterococci; thus migration of bacteria in the periurethral mucous sheath appeared to be the most common pathway by which bacteria gained entry into the bladder in this study. Catheter care and disinfection of the drainage bag outflow tube as used in this study remain unproven methods of preventing catheter-associated bacteriuria. Preconnected catheters with junction seals were used in both treated and untreated patients and, on the basis of previous studies, appear to be effective in reducing junction disconnections and bacteriuria. Therefore we conclude that the use of several simultaneous measures to prevent catheter-associated urinary infections is no more effective than the use of preconnected catheters with junction seals alone and is clearly more expensive.

Bacteriuria↗

PubMed1991

Daily meatal care for prevention of catheter-associated bacteriuria: results using frequent applications of polyantibiotic cream.

OBJECTIVE: To determine the efficacy of meatal treatment with a polyantibiotic cream in the prevention of bacteriuria during transurethral bladder catheterization. DESIGN: Randomized controlled trial. SETTING: Community teaching hospital. PATIENTS: Adult patients who underwent closed urinary catheter drainage for short and intermediate durations (two to 30 days). INTERVENTION: Polyantibiotic cream containing polymyxin B sulfate, neomycin sulfate, and gramicidin was applied to the urethral meatus-catheter interface three times daily from the first day of catheterization until bacteriuria was found. The onset of bacteriuria was defined as the day the colonizing species first achieved a colony count of greater than or equal to 1000 colonies/ml. Patients randomized to the control group received routine meatal care with cleansing of the meatal surface during daily bathing. RESULTS: Among 2,923 patients who were randomly allocated to receive either the protocol meatal care or routine care, the evaluable study population consisted of 747 patients who were nonbacteriuric and who remained catheterized for more than two days. Overall, 26 (6.8%) of 383 patients given the polyantibiotic treatment acquired bacteriuria, as compared to 37 (10.1%) of 364 patients not given this treatment (p = .167). A Cox proportional hazards regression analysis showed that, among putative risk factors including lack of meatal care, only female gender, a meatal swab culture yielding gram-negative rods or enterococci, and lack of antibiotic use during catheterization were independently associated with the development of bacteriuria. CONCLUSIONS: The adverse effect of meatal care noted in earlier studies of a disinfectant ointment applied twice daily was not found in this study of an antimicrobial preparation in a cream vehicle applied three times daily. However, the results do not support meatal care as an efficacious method to prevent catheter-associated bacteriuria in all patients.

Aged↗

PubMed1991

Surveillance for quality assessment: IV. Surveillance using a hospital information system.

Hospital surveillance for infection control purposes is a well-accepted method of following nosocomial infections in U.S. hospitals. However, hospital surveillance is being increasingly performed for nosocomial events in noninfectious areas, such as quality assurance and other areas of outcomes research. For the continued development of hospital surveillance in all these areas, dramatic growth in the amount of information collected will occur. To accommodate this growth and to validate new approaches in these areas, large amounts of data collection will be necessary. Collection of these data will be quite difficult without the creation of clinical hospital data bases in which large amounts of information are collected as a routine part of patient care, not as an elaborate addition to patient care. Automated hospital information systems, such as the HELP system, can facilitate the conduct of ongoing hospital surveillance not only in infection control but also in a broad range of areas, such as quality improvement outcomes research and cost-containment areas.

Cross Infection↗

PubMed1991

Development of a computerized adverse drug event monitor.

Adverse events during drug therapy are receiving renewed attention. Some adverse drug events (ADEs) are identified only after the widespread clinical use of a drug. The Food and Drug Administration advocates post-marketing surveillance systems to provide early warnings of previously undetected ADEs. The identification of ADEs by U.S. hospitals is now required by the Joint Commission on Accreditation of Healthcare Organizations. We developed a series of computer programs and data files on the HELP System to help identify ADEs. The HELP System monitors laboratory test results, drug orders, and data entered through a computerized ADE reporting program. A nurse or pharmacist verifies computer alerts of possible ADEs. The computerized system identified 401 ADEs during the first year of use compared to 9 by voluntary reporting methods during the previous year (p less than 0.001). This paper describes the development and early use of the computerized ADE surveillance system.

Adverse Drug Reaction Reporting Systems↗

PubMed1990

Failure of cephalosporins to prevent Staphylococcus aureus surgical wound infections.

Approximately 35,000 Staphylococcus aureus surgical wound infections occur annually in the United States. To investigate why S aureus causes infection despite the perioperative administration of cephalosporins, we compared 35 methicillin-susceptible isolates recovered from deep wound infections that complicated cefazolin prophylaxis (18 of 1650 patients) and cefamandole prophylaxis (17 of 3702 patients) with 64 colonizing isolates from presurgical patients. Compared with both colonizing and cefamandole-associated isolates, S aureus isolates from cefazolin-associated infections were more resistant to cefazolin by specialized assays. Staphylococcus aureus isolates that produced the A and C variants of staphylococcal beta-lactamase were associated with infections following cefazolin and cefamandole prophylaxis, respectively. These isolates hydrolyze the respective cephalosporins rapidly, suggesting that staphylococcal survival after perioperative prophylaxis may be mediated by in vivo degradation of the prophylactically administered cephalosporin. These data indicate that some S aureus wound infections occur because of deficiencies in antimicrobial effectiveness that are not detectable by routine susceptibility tests. This finding has important implications for the therapy and prevention of S aureus infection.

Cefamandole↗

PubMed1990

Therapeutic antibiotic monitoring: surveillance using a computerized expert system.

STUDY OBJECTIVE: To develop and evaluate a computerized system to monitor therapeutic antibiotics in a hospital setting. MATERIAL AND METHODS: From November 1986 through October 1987, we prospectively monitored 1,632 hospitalized patients who had 2,157 microbiology specimens sent for culture and sensitivity testing. During the study period, computer algorithms were used to identify patients whose antibiotic therapy was inappropriate in relation to microbiology culture and sensitivity data. When inconsistencies occurred between antibiotic therapy and in vitro sensitivity data, computer algorithms generated therapeutic antibiotic monitor (TAM) alerts. A clinical pharmacist then notified the attending physician of the alert. RESULTS: Antibiotic therapy was identified by the computer as inappropriate in 696 instances (32%). After we eliminated false-positive alerts, 420 evaluable TAM alerts remained. Physicians responded to the TAM alerts by either changing or starting antimicrobial therapy in 125 cases (30%). Moreover, physicians were previously unaware of the relevant susceptibility test results in 49% of the alerts. CONCLUSION: Computer-assisted monitoring is an efficient and promising method to identify and correct errors in antimicrobial prescribing and to assure the appropriate use of therapeutic antibiotics.

Algorithms↗

PubMed1990

Streptococcus mitis sepsis in bone marrow transplant patients receiving oral antimicrobial prophylaxis.

PURPOSE: Streptococcal infection has increasingly become a problem in neutropenic patients. We report on an outbreak of Streptococcus mitis sepsis in six bone marrow transplant patients receiving oral antimicrobial prophylaxis. PATIENTS AND METHODS: We performed an epidemiologic study of all patients in our bone marrow transplant program from 1986 to 1988. The hospital and microbiology records for all patients were reviewed. All bone marrow patients were treated according to specified protocols, including an oral prophylactic antimicrobial regimen that was changed in late 1987 from vancomycin/polymyxin/tobramycin to norfloxacin. Identification, susceptibility testing, and whole cell protein analysis of streptococcal isolates were performed at the Reference and Antimicrobial Investigations Laboratories at the Centers for Disease Control. RESULTS: We detected six cases of S. mitis sepsis among 21 patients undergoing bone marrow transplantation. No other concurrent pathogen was isolated from any patient at the time of the S. mitis bacteremia. Bacteremia developed within 72 hours of transplant in five of six patients and was associated with severe mucositis in four patients. An environmental study failed to reveal any common source for the outbreak, and whole cell protein analysis of all six S. mitis isolates revealed each to be distinct. Of 12 patients receiving oral vancomycin/polymyxin/tobramycin, one developed S. mitis bacteremia, versus five of nine patients receiving norfloxacin (p less than 0.03). CONCLUSION: We believe S. mitis bacteremia is a potential complication of bone marrow transplantation and is associated with antimicrobial prophylaxis with norfloxacin, especially in the setting of mucositis.

Administration, Oral↗