Antibiotic misuse in two clinical situations: positive blood culture and administration of aminoglycosides

The need for an antibiotic stewardship program in a hospital using a computerized pre-authorization system

OBJECTIVES

Antimicrobial stewardship programs (ASPs) have an important role in the appropriate utilization of antibiotics. Some of the core strategies recommended for ASPs are pre-authorization and prospective audit and feedback. In Turkey, a unique nationwide antibiotic restriction program (NARP) has been in place since 2003. The aim of this study was to measure the effect of a prospective audit and feedback strategy system along with the NARP.

METHODS

A prospective quasi-experimental study was designed and implemented between March and June 2017. A computerized pre-authorization system was used as an ASP strategy to approve the antibiotics. During the baseline period, patients with intravenous (IV) antibiotic use ≥72 h were monitored without intervention. In the second period, feedback and treatment recommendations were given to attending physicians in the case of IV antibiotic use ≥72 h. The modified criteria of Kunin et al. and Gyssens et al. were followed for appropriateness of prescribing. Days of therapy (DOT) and length of stay (LOS) were calculated and compared between the two study periods.

RESULTS

A total of 866 antibiotic episodes among 519 patients were observed. A significant reduction in systemic antibiotic consumption was observed in the intervention period (575 vs. 349 DOT per 1000 patient-days; p <  0.001). On multivariate analysis, prospective audit and feedback (odds ratio 1.5, 95% confidence interval 1.09-2.04; p = 0.011) and pre-authorization of restricted antibiotics (odds ratio 1.7; 95% confidence interval 1.2-2.31; p =  0.002) were the predictors of appropriate antimicrobial use. Mean LOS was decreased by 2.9 days (p =  0.095).

CONCLUSIONS

This study showed that the antimicrobial restriction program alone was effective, but the system should be supported by a tailored ASP, such as prospective audit and feedback.

Usage Pattern and Serum Level Measurement of Amikacin in the Internal Medicine Ward of the Largest Referral Hospital in the South of Iran: A Pharmacoepidemiological Study

BACKGROUND

The inappropriate use of aminoglycosides has harmful effects such as the development of resistant pathogens and the incidence of nephrotoxicity and ototoxicity. Therefore, drug utilization evaluation of these drugs may improve their usage remarkably. The aim of this study was to assess the usage pattern of amikacin in an internal medicine ward.

METHODS

This cross-sectional study was conducted in the Internal Medicine Ward of Nemazee Teaching Hospital, Shiraz, Iran, in 2011. The guideline for amikacin use was approved by the institutional Pharmacy and Therapeutics Committee, and the study criteria were developed to assess several parameters involved in amikacin therapy such as appropriateness of drug use, dosage, duration of therapy, toxicity monitoring, and serum concentration assay. Serum concentration was assayed using a Cobas Mira AutoAnalyzer. Clinical and paraclinical parameters such as glomerular filtration rate, culture, microbial sensitivity, white blood cell count, and fever were collected.

RESULTS

Sixty-three patients were evaluated. Fifty-seven percent of the patients needed dose readjustment; however, it was not performed for 89% of them. Culture between 48 and 72 hours after amikacin administration was not controlled for 79% of the patients. In 19% of the patients, optimum therapeutic effect was not achieved. The mean±SD of the trough and peak concentrations was 7.63±5.4 μg/mL and 15.67±7.79 μg/mL, respectively. Forty-five percent of the trough and 38% of the peak levels were within the therapeutic range. The overall adherence of amikacin usage to the guideline was only 48%.

CONCLUSION

To achieve appropriate treatment and prevent toxic effects, we recommend that pharmacokinetic dosing methods, amikacin guideline, and serum monitoring be considered.

Use of antibiotics among non-medical students in a Nigerian university

BACKGROUND

Antibiotic misuse is a major contributory factor to treatment failure, antibiotic resistance and high healthcare costs.

OBJECTIVES

To evaluate level of self-reported antibiotic misuse among non-medical undergraduate students of a Nigerian university.

METHODS

Respondents' knowledge of antibiotics and disposal system for left-over antibiotics were explored using a structured questionnaire. Data were summarized with descriptive statistics. Chi square was used to evaluate relationship between specific categorical variables and respondents' opinions with p<0.05.

RESULTS

More than half the respondents obtained their antibiotics through doctor's prescriptions (273; 68.3%). The study revealed gross antibiotic misuse with majority, (298;74.5%) either by keeping left-over antibiotics for future use or throwing it away with refuse. Respondents (289; 72.3%) sometimes forgot to take the antibiotics. Financial constraints (73; 18.3%), long duration of treatment (70; 17.5%), side effects experienced (60;15.0%), polypharmacy (56;14.0%), tablet size (45;11.3%), and perceived low level of confidence in the prescriber (11; 2.8%) were major reasons for non-adherence. Course of study of respondents had no significant effect on respondents' knowledge or adherence (p>0.05).

CONCLUSION

Misuse of antibiotics among non-medical undergraduate students in a Nigerian university setting is pervasive suggesting an urgent need for enlightenment on rational use and disposal of antibiotics.

Health Care-Associated Infection Prevention and Control: Pharmacists' Role in Meeting National Patient Safety Goal 7

Health care-associated infections and antimicrobial resistance are continually increasing, with fewer drugs available for effective treatment. Potential benefits of infection control and antimicrobial stewardship programs include improvements in antibiotic use and conversion from intravenous (IV) to oral antibiotics and reductions in resistance and infection rates and length of hospital stay. NorthShore University HealthSystem in Evanston, Illinois, was the first large hospital system in North America that adopted universal inpatient surveillance for methicillin-resistant Staphylococcus aureus (MRSA). Results showed that nasal MRSA was a powerful predictor of MRSA disease and antibiotic resistance in other organisms. MRSA infections occurring up to 30 days posthospitalization decreased by approximately 70%. At the Hospital of Saint Raphael, a community teaching hospital in New Haven, Connecticut, an antimicrobial stewardship pilot program focused on automatic conversation from IV to oral antimicrobials and appropriate antimicrobial use. The percentage of patients receiving oral fluconazole increased from 63% to 77%; the percentage of those receiving oral linezolid increased from 54% to 71%. Total antibiotic use decreased by 6%. Based on the 60-day trial, potential cost savings were estimated as $874,000 annually, less the cost of a pharmacist's salary and benefits. Infection control and antimicrobial stewardship programs offer pharmacists new opportunities for helping improve patient safety and quality of care. Pharmacy-medical staff partnership, combined with support from microbiology, infection control, information technology, and hospital administration, is key to a successful program.

Follow-up of antibiotic prophylaxis: impact on compliance with guidelines and financial outcomes

In order to enhance the quality of antibiotic use, a new financial system was introduced in Belgium in 1997, which links reimbursement of antibiotic costs incurred during prophylaxis in surgery and obstetrics to compliance with evidence-based guidelines. At University Hospitals Leuven (UHL), this reimbursement scheme was supplemented with a follow-up programme in 2001 that informs physicians of their compliance with the guidelines and outlines the financial consequences of their use of prophylactic antibiotics. The aim of this paper is to evaluate the impact of the follow-up programme developed and implemented by a clinical pharmacist at UHL. The analysis drew on data on consumption and costs of antibiotics used in standard prophylaxis that were retrieved from patient invoices. Both financial outcomes and results on consumption patterns of antibiotics point to an increasing compliance with guidelines. An average annual loss of 92,353 Euro associated with prophylactic antibiotic use prior to the implementation of the follow-up programme evolved into a profit of 27,269 Euro following its introduction. The share of consumption of prophylactic antibiotics held by cefazolin and metronidazole, the two main antibiotics recommended by the guidelines, increased substantially or remained stable as a result of the follow-up programme, whereas the shares held by other antibiotics generally fell. Moreover, the range of antibiotics consumed during standard prophylaxis narrowed. This follow-up programme thus reduced antibiotic costs, improved profitability and increased physician compliance with guidelines.

Adjustment of antibiotic treatment according to the results of blood cultures leads to decreased antibiotic use and costs

INTRODUCTION

To avoid the use of unnecessary broad-spectrum antibiotics, empirical therapy of bacteraemia should be adjusted according to the results of blood cultures.

OBJECTIVES

To investigate whether the results of blood cultures led to changes in antibiotic use and costs in a tertiary-care university hospital in Norway.

METHODS

Medical records from all patients with positive blood cultures in 2001 were analysed retrospectively. Factors predisposing to infections, results of blood cultures, antibiotic use and outcome were recorded. The influence of blood culture results on antibiotic treatment and costs were analysed.

RESULTS

The antibiotic use in 226 episodes of bacteraemia in 214 patients was analysed. According to the guidelines empirical antibiotic treatment should be adjusted in 166 episodes. Antibiotic use was adjusted in 146 (88%) of these 166 episodes, which led to a narrowing of therapy in 118 (80%) episodes. Compared with empirical therapy there was a 22% reduction in the number of antibiotics. Adjustment of therapy was more often performed in Gram-negative bacteraemia and polymicrobial cultures than in Gram-positive bacteraemia. In bacteraemia caused by ampicillin-resistant Escherichia coli, ampicillin was mostly replaced by ciprofloxacin. The cost for 7 days adjusted therapy in 146 episodes was euro19,800 (23%) less than for 7 days of empirical therapy.

CONCLUSIONS

Adjustment of antibiotic therapy according to the results of blood cultures led to a reduction in the number of antibiotics and a narrowing of antibiotic therapy. The costs for antibiotics decreased.

Evaluation of antibiotic use in intensive care units of a tertiary care hospital in Turkey

The object of this study was to evaluate the appropriateness of antibiotic use in relation to diagnosis and bacteriological findings in the intensive care units (ICUs) of a 1100-bed referral and tertiary care hospital with an antibiotic restriction policy in Turkey. Between June and December 2002, patients who received antibiotics in the medical and surgical ICUs were evaluated prospectively. Two infectious diseases (ID) specialists assessed the antibiotics ordered daily. Of the 368 patients admitted to the ICUs, 223 (60.6%) received 440 antibiotics. The most frequently prescribed antibiotics were first-generation cephalosporins (16.1%), third-generation cephalosporins (15.2%), aminoglycosides (12.1%), carbapenems (10.7%) and ampicillin-sulbactam (8.7%). Antibiotic use was inappropriate in 47.3% of antibiotics. ID specialists recommended the use of 47% of all antibiotics. An antibiotic order without an ID consultation was more likely to be inappropriate [odds ratio (OR)=13.2, P<0.001, confidence intervals (CI)=4.4-39.5]. Antibiotics ordered empirically were found to be less appropriate than those ordered with evidence of culture and susceptibility results (OR=3.8, P=0.038, CI=1.1-13.1). Inappropriate antibiotic use was significantly higher in patients who had surgical interventions (OR=3.6, P=0.025, CI=1.2-10.8). Irrational antibiotic use was high for unrestricted antibiotics. In particular, antibiotic use was inappropriate in surgical ICUs. Additional interventions such as postgraduate training programmes and elaboration of local guidelines could be beneficial.

Compliance with an infectious disease specialist's advisory consultations on targeted antibiotic usage

This study was conducted to evaluate the appropriateness of the use of targeted antibiotics, and to analyze compliance and the short-term impact of targeted antibiotic advisory consultations, as implemented in our hospital in October 2002. Targeted antibiotics included glycopeptides, carbapenems, antipseudomonal cephalosporins, and aminoglycosides. A total of 339 prescriptions were reviewed from October 2002 through March 2003. Antimicrobial utilization density (AUD), which was the defined daily dose divided by 1000 patient days, was compared quarterly. Overall, 85.6% of the prescriptions were inappropriate, with 73.7% being inappropriate for therapeutic use and 100% inappropriate for prophylactic use. The overall compliance rate of attending physicians with the antibiotic advisory consultations was 46.5%. Compliance was higher in medical services than in surgical services (64.2% vs 43.1%; P = 0.005) and for therapeutic use than for prophylactic use (54.7% vs 36.5%; P = 0.001). The use of all parenteral antibiotics in the hospital decreased, from 770.8 AUD during the first quarter in 2002 to 626.8 AUD during the second quarter in 2003 (P < 0.01). In conclusion, inappropriate antibiotic use for treatment and prophylaxis is common in our hospital. A targeted antibiotic advisory consultation may be an alternative means of ensuring more appropriate antibiotic use. However, more efficient antibiotic control measures should be developed and implemented, and prospective and continuous monitoring of antibiotic use is required.

Structured representation of the pharmacodynamics section of the summary of product characteristics for antibiotics: application for automated extraction and visualization of their antimicrobial activity spectra

OBJECTIVE

The aim of this study was to construct automatically a knowledge base concerning the pharmacodynamic properties of antibiotics and a visualization tool.

DESIGN

The authors studied the various guidelines used to write the pharmacodynamics section of the Summary of Product Characteristics (SPC) for antibiotics and constructed a conceptual model of the information. Particular words, syntagms, and punctuation elements were marked in the SPC texts, and automatic extraction was then used to build a knowledge base. This base was used to create dynamic HTML tables displaying the activity spectra of the antibiotics.

MEASUREMENTS

The authors analyzed the performances of automatic extraction (recall and precision).

RESULTS

The conceptual pharmacodynamics model dealt with antibiotics, pathogens, susceptibility tests, and the prevalence of resistance. Automatic extraction had a recall rate of 97.9% and a precision of 96.2%. The tool displaying antibiotic spectra and resistance prevalences used color codes to identify differences in susceptibility.

CONCLUSION

This tool can provide an overview of the prevalence of resistance as expressed in SPC in primary care settings. Its potential impact should be evaluated.

Evaluation of antibiotic use in a hospital with an antibiotic restriction policy

The study was designed to evaluate rational antibiotic use in relation to diagnosis and bacteriological findings. All hospitalized patients who received antibiotics were evaluated by a cross-sectional study. Of the 713 patients hospitalized, 281 (39.4%) patients received 377 antibiotics. Among 30 different antibiotics the most frequently requested were first generation cephalosporins (19.9%), ampicillin-sulbactam (19.1%) and aminoglycosides (11.7%). Antibiotic use was appropriate in 64.2% of antibiotic requests. In analysis of appropriate use, a request after an infectious diseases consultation was a frequent reason (OR=14, P<0.001, CI=0.02-0.24). Antibiotics requested in conjunction with susceptibility results were found to be more appropriate than those ordered empirically (OR=4.5, P=0.017, CI=0.06-0.76). Inappropriate antibiotic use was significantly higher among unrestricted antibiotics than restricted ones (P<0.001). Irrational antibiotic use was high for unrestricted antibiotics. Additional interventions such as postgraduate training programmes and elaboration of local guidelines could be beneficial.

Etiology of fever and opportunities for reduction of antibiotic use in a pediatric intensive care unit

OBJECTIVE

To determine the cause of fever in critically ill children and to identify opportunities for reducing antibiotic use in this population.

DESIGN

Prospective case series.

SETTING

A tertiary-care medical-surgical pediatric intensive care unit (PICU).

PATIENTS

Children admitted to the PICU who experienced fever (axillary temperature >38.3 degrees C).

MEASUREMENTS

Consecutive children who were febrile at any point in their PICU stay were investigated over two winter seasons. Etiology of the fever was determined by physical examination and routine microbiology and radiographic tests. Three subgroups were reviewed to approximate the number of antibiotic-days that could have been reduced; namely, those with an indeterminate source, those with a documented viral infection, and those receiving a prolonged course of antibiotics. A set of standards reflecting common antibiotic use then was applied to these three patient groups.

RESULTS

Of 211 subjects, the majority (83.3%) had either a definitive or suspected focus for their fever, and nearly all of these patients were judged to have an infectious etiology. The study population received a total of 2,036 antibiotic-days. Despite the high incidence of infectious causes of fever in our subjects, however, approximately 15% of total antibiotic-days could have been reduced by applying common-use standards.

CONCLUSIONS

Fever in the PICU was usually of defined focus and infectious in origin. However, among febrile patients in the PICU, substantial opportunity exists for reduction of antibiotic use. Trials determining the safety of antibiotic reduction in this population should be pursued vigorously.

Do guidelines for community-acquired pneumonia improve the cost-effectiveness of hospital care?

There is growing pressure to demonstrate the value of practice guidelines. We have reviewed the evidence that guidelines for the treatment of community-acquired pneumonia (CAP) change current practices and that the standardization of practices reduces costs and/or improves outcome. The most obvious barrier to implementation of the guidelines is lack of knowledge about their content; equally important are the attitudes and behavior of professionals, patients, and their caregivers. Guidelines may improve the outcome of CAP, provided that there is an association between variations in outcome and some specific processes of care. Conversely, when there is no such relationship, guidelines may reduce the cost of care without having an adverse effect on outcome. The cost-effectiveness of CAP guidelines in an individual hospital depends on the systems that are available to identify patients with CAP and to measure the processes of care. There is good evidence that following the recommendations of the CAP guidelines does improve the cost-effectiveness of care and, therefore, that an audit of CAP may be worth the effort.

Quality measures of antimicrobial drug use

Antimicrobial use is the major determinant in the development of resistance. Many parameters of importance for optimal quality of antimicrobial therapy have already been defined. Maximal efficacy of the treatment should be combined with minimal toxicity at the lowest cost. Quality of antimicrobial drug use is dependent on knowledge of many aspects of infectious diseases. Considering efficacy, many of our indications for antimicrobial use need critical evaluation. Irrational use should be discouraged. Avoidance of the development of resistance is a quality parameter that will need increasing attention. This paper reviews the well-established factors that may influence the appropriateness of pharmacotherapy with antimicrobial drugs. It cites recent evidence supporting principles of prudent prescribing and gives an overview of audits that have addressed these parameters. Measures relating to resistance are discussed.

Inadequate treatment of nosocomial infections is associated with certain empiric antibiotic choices

OBJECTIVE

The purpose of this study was to determine the impact of scheduled changes of antibiotic classes, used for the empirical treatment of suspected or documented Gram-negative bacterial infections, on the occurrence of inadequate antimicrobial treatment of nosocomial infections.

DESIGN

Prospective observational study.

SETTING

Medical (19-bed) and surgical (18-bed) intensive care units in an urban teaching hospital.

PATIENTS

A total of 3,668 patients requiring intensive care unit admission were prospectively evaluated during three consecutive time periods.

INTERVENTIONS

During each time period, one antibiotic class was selected for the empirical treatment of Gram-negative bacterial infections as follows: time period 1 (baseline period) (1,323 patients), ceftazidime; time period 2 (1,243 patients), ciprofloxacin; and time period 3 (1,102 patients), cefepime.

MEASUREMENTS AND MAIN RESULTS

The overall administration of inadequate antimicrobial treatment for nosocomial infections decreased during the course of the study (6.1%, 4.7%, and 4.5%; p = .15). This was primarily because of a statistically significant decrease in the administration of inadequate antibiotic treatment for Gram-negative bacterial infections (4.4%, 2.1%, and 1.6%; p < .001). There were no statistically significant differences in the overall hospital mortality rate among the three time periods (15.6%, 16.4%, and 16.2%; p = .828) despite a significant increase in severity of illness as measured with Acute Physiology and Chronic Health Evaluation (APACHE) II scores (15.3 +/- 7.6, 15.7 +/- 8.0, and 20.7 +/- 8.6; p < .001). The hospital mortality rate decreased significantly during time period 3 (20.6%) compared with time period 1 (28.4%; p < .001) and time period 2 (29.5%; p < .001) for patients with an APACHE II score > or = 15.

CONCLUSIONS

These data suggest that scheduled changes of antibiotic classes for the empirical treatment of Gram-negative bacterial infections can reduce the occurrence of inadequate antibiotic treatment for nosocomial infections. Reducing inadequate antibiotic administration may improve the outcomes of critically ill patients with APACHE II scores > or = 15.

Rotation and restricted use of antibiotics in a medical intensive care unit. Impact on the incidence of ventilator-associated pneumonia caused by antibiotic-resistant gram-negative bacteria

To test the hypothesis that a new program of antibiotic strategy control can minimize the incidence of ventilator-associated pneumonia (VAP) caused by potentially antibiotic-resistant microorganisms, we performed a prospective before-after study in 3, 455 patients admitted to a single intensive care unit over a 4-yr period. Regarding the bacterial ecology and the increasing antimicrobial resistance in our medical intensive care unit (MICU), we decided to vary our choice of empiric and therapeutic antibiotic treatment, with a supervised rotation, and a restricted use of ceftazidime and ciprofloxacin, which were widely prescribed before this scheduled change. For all patients, VAP was diagnosed based on the results of quantitative culture of bronchoalveolar lavage specimens (>/= 10(4) cfu/ml). We studied 1,044 and 1,022 patients requiring more than 48 h of mechanical ventilation (MV), respectively, in the before-period (2 yr: 1995-1996) and the after-period (2 yr: 1997-1998). We observed a decrease from 231 consecutive episodes of VAP in the before-period to 161 episodes of VAP in the after-period (p < 0.01), particularly for VAP occurring before 7 d of MV. The total number of potentially antibiotic-resistant gram-negative bacilli responsible for VAP such as Pseudomonas aeruginosa, Burkholderia cepacia, Steno-trophomonas maltophilia, and Acinetobacter baumanii decreased from 140 to 79 isolated bacilli. The susceptibilities of these bacteria to the antibiotics regimen increased significantly, especially for P. aeruginosa and B. cepacia. The percentage of methicillin-sensitive Staphylococcus aureus increased significantly from 40% to 60% of S. aureus responsible for VAP. These results suggest that a new strategy of antibiotics use could be an efficient means to reduce the incidence of VAP caused by antibiotic-resistant bacteria. Nevertheless, further studies are needed to validate these data.

[The economic impact of inadequate prescriptions]

The impact of antibiotic therapy has gone to considerable expense. The review of literature demonstrates that an optimal use of economical resources can be achieved by an improvement of medical prescriptions. This improvement of prescriptions can be obtained for prophylaxy and for curative therapy. Cost savings can be as high as one-year budget for the recruitment of an infectious diseases consultant.

[The good use of antibiotics in intensive care: results of a program for rationalization of prescriptions]

OBJECTIVE

To assess the impact of an antibiotic prescribing programme in a intensive therapy unit.

TYPE OF STUDY

Prospective comparative study.

METHODS

We compared antibiotic prescriptions and bacterial susceptibility to antimicrobial agents before and after introduction of a programme focusing on injection control and therapeutic indications.

RESULTS

The introduction of the programme resulted in a major decrease in antibiotic administration. Moreover, the susceptibility of Pseudomonas aeruginosa to ticarcillin increased from 40 to 68%, and susceptibility of Staphylococcus aureus to methicillin increased from 55 to 73%.

CONCLUSIONS

Antibiotic control policies must be considered integral to any effort to decrease resistance and cost of therapy with antibiotics.

Implementation of an educational program and an antibiotic order form to optimize quality of antimicrobial drug use in a department of internal medicine

In a study designed to evaluate the effects of an educational program and an antibiotic order form on the quality of antimicrobial drug use, a prospective analysis was conducted in the department of internal medicine of a 948-bed university hospital. Following a quality-of-use review of all consecutive courses of antimicrobial drugs prescribed during four weeks, an educational program was conducted and an antibiotic order form introduced. After four years, an identical review was performed. In the first review, 109 (31%) of 347 patients were prescribed antimicrobial drugs. Only 40% of the prescriptions were considered definitely appropriate, and 13% were considered unjustified. There was a certain degree of underutilization, and only 67% of clinical isolates were susceptible to empirical therapy. In the review performed after intervention, 164 (21%) of 796 patients were given antimicrobial drugs. Defined daily doses per 100 bed days increased from 59.8 to 72.6. Fifty-three percent of the prescriptions were judged optimal, and only 9% were judged unjustified. Ninety percent of the clinical isolates were susceptible to empirical therapy. After one year, compliance with the antibiotic order forms on a voluntary basis reached 77%, documenting 86% of antimicrobial drug costs. As a result, the antibiotic order form will be useful for surveillance, if logistic support is provided by the pharmacy. The combination of several measures leads to improved quality of use. As correctly predicted by the first evaluation, improvement in quality resulted in increased drug consumption by fewer patients and a higher cost per bed day.

Empiric antibiotic treatment and the misuse of culture results and antibiotic sensitivities in patients with community-acquired bacteraemia due to urinary tract infection

Recent data suggests that culture isolations and susceptibility profiles are overlooked, misinterpreted and are not a major determinant in the process of selecting anti-bacterial therapy. Compliance with empiric antibiotic protocols, relationship between blood culture results, change and selection of secondary antibiotic regimens and effect on outcome and length of hospitalization were assessed prospectively in 134 episodes of community-acquired bacteraemia due to urinary tract infection in adults. Empiric antibiotic protocols were correct in 112 episodes (83.6%), excessive in 12 episodes (8.95%) and inappropriate in 10 (7.5%) episodes, with no significant difference in outcome or length of hospitalization. Excluding early deaths, the adequacy of the initial antibiotic therapy was clearly associated with mortality (four deaths out of eight episodes treated incorrectly vs. 21/117 treated appropriately [P = 0.029]), but not with length of hospitalization. Antibiotic change was theoretically required in 92/119 (77.3%) episodes (27 [29.3] incorrect regimen, 65 [70.65%] excessive regimen), but actual change was made in only 43 episodes, of which three protocols were changed from a correct to an incorrect regimen, and one patient continued to receive an incorrect regimen. Eighteen out of 34 changes in excessive protocols were still excessive. Adequacy of secondary antibiotic treatment was clearly associated with outcome (5/10 vs. 4/109 [P<0.001]). Excessive protocols were not associated with better outcome or shorter hospital stay. Change of antibiotic regimen was associated with the presence of background diseases (5.6-fold increase) and inversely with hospitalization on the urology ward (0.254), but no independent factors associated with correct or incorrect secondary regimens could be identified. Although the compliance rate with empiric protocols was satisfactory, in many bacteraemic episodes blood culture results and antibiotic sensitivity profiles are overlooked, leading to higher mortality and excessive, unjustified use of expensive and broad-spectrum antibiotics. We could not identify factors associated with this disregard of susceptibility profiles.

Scheduled change of antibiotic classes: a strategy to decrease the incidence of ventilator-associated pneumonia

The purpose of this study was to determine the impact of a scheduled change of antibiotic classes, used for the empiric treatment of suspected gram-negative bacterial infections, on the incidence of ventilator-associated pneumonia and nosocomial bacteremia. Six hundred eighty patients undergoing cardiac surgery were evaluated. During a 6-mo period (i.e., the before-period), our traditional practice of prescribing a third generation cephalosporin (ceftazidime) for the empiric treatment of suspected gram-negative bacterial infections was continued. This was followed by a 6-mo period (i.e., the after-period) during which a quinolone (ciprofloxacin) was used in place of the third-generation cephalosporin. The incidence of ventilator-associated pneumonia was significantly decreased in the after-period (n = 327) compared with the before-period (n = 353) (6.7 versus 11.6%; p = 0.028). This was primarily due to a significant reduction in the incidence of ventilator-associated pneumonia attributed to antibiotic-resistant gram-negative bacteria (0.9 versus 4.0%; p = 0.013). Similarly, we observed a lower incidence of bacteremia attributed to antibiotic-resistant gram-negative bacteria in the after-period compared with the before-period (0.3 versus 1.7%; p = 0.125). These data suggest that a scheduled change of antibiotic classes can reduce the incidence of ventilator-associated pneumonia attributed to antibiotic-resistant gram-negative bacteria.

The impact of nosocomial infections on patient outcomes following cardiac surgery

STUDY OBJECTIVE

To evaluate the relationship between nosocomial infections and clinical outcomes following cardiac surgery, and to identify risk factors for the development of nosocomial infections in this patient population.

DESIGN

Prospective cohort study.

SETTING

Barnes-Jewish Hospital, St. Louis, a university-affiliated teaching hospital.

PATIENTS

Six hundred five consecutive patients undergoing cardiac surgery.

INTERVENTIONS

Prospective patient surveillance and data collection.

MAIN OUTCOME MEASURES

Occurrence of nosocomial infections, multiorgan dysfunction, hospital mortality, and risk factors for the acquisition of nosocomial infections.

RESULTS

One hundred thirty-one (21.7%) patients acquired at least one nosocomial infection following cardiac surgery. Four independent risk factors for the development of a nosocomial infection were identified: the duration of mechanical ventilation, postoperative empiric antibiotic administration, the duration of urinary tract catheterization, and female gender. Thirty (5.0%) patients died during their hospitalization. The mortality rate of patients acquiring a nosocomial infection (11.5%) was significantly greater than the mortality rate of patients without a nosocomial infection (3.2%) (odds ratio [OR]=4.0; 95% confidence interval [CI]=2.7 to 5.8; p<0.001). Multiorgan dysfunction was found to be the most important independent determinant of hospital mortality (adjusted OR=23.8; 95% CI=13.5 to 42.1; p<0.001) along with the aortic cross-clamp time (adjusted OR=2.3; 95% CI=1.7 to 3.0; p=0.002) and severity of illness as measured by APACHE II (acute physiology and chronic health evaluation) (adjusted OR=1.1; 95% CI=1.1 to 1.2; p=0.019). Ventilator-associated pneumonia, clinical sepsis, female gender, the cardiopulmonary bypass time, and severity of illness were identified as independent risk factors for the development of multiorgan dysfunction. Among hospital survivors, patients acquiring a nosocomial infection had longer hospital lengths of stay compared to patients without a nosocomial infection (20.1+/-13.0 days vs 9.7+/-4.5 days; p<0.001).

CONCLUSIONS

Nosocomial infections, which are common following cardiac surgery, are associated with prolonged lengths of hospitalization, the development of multiorgan dysfunction, and increased hospital mortality. These data suggest potential interventions for the prevention of nosocomial infections following cardiac surgery that could substantially improve patient outcomes and decrease medical care costs.

The clinical significance of positive blood cultures in the 1990s: a prospective comprehensive evaluation of the microbiology, epidemiology, and outcome of bacteremia and fungemia in adults

To assess changes since the mid-1970s, we reviewed 843 episodes of positive blood cultures in 707 patients with septicemia. The five most common pathogens were Staphylococcus aureus, Escherichia coli, coagulase-negative staphylococci (CNS), Klebsiella pneumoniae, and Enterococcus species. Although CNS were isolated most often, only 12.4% were clinically significant. Half of all episodes were nosocomial, and a quarter had no recognized source. Leading identifiable sources included intravenous catheters, the respiratory and genitourinary tracts, and intraabdominal foci. Septicemia-associated mortality was 17.5%. Patients who received appropriate antimicrobial therapy throughout the course of infection had the lowest mortality (13.3%). Multivariate analysis showed that age (relative risk [RR], 1.80), microorganism (RR, 2.27), source of infection (RR, 2.86), predisposing factors (RR, 1.98), blood pressure (RR, 2.29), body temperature (RR, 2.04), and therapy (RR, 2.72) independently influenced outcome. Bloodstream infections in the 1990s are notable for the increased importance of CNS as both contaminants and pathogens, the proportionate increase in fungi and decrease in anaerobes as pathogens, the emergence of Mycobacterium avium complex as an important cause of bacteremia in patients with advanced human immunodeficiency virus infection, and the reduction in mortality associated with infection.

Determinants of mortality and multiorgan dysfunction in cardiac surgery patients requiring prolonged mechanical ventilation

OBJECTIVES

To identify characteristics associated with mortality and the development of multiorgan dysfunction in patients who had undergone cardiac surgery and required prolonged mechanical ventilation, ie, > 48 h.

DESIGN

A prospective cohort study.

SETTING

Barnes Hospital, St. Louis, an academic tertiary care center.

PATIENTS OR OTHER PARTICIPANTS

A total of 107 consecutive patients undergoing cardiac surgery and requiring prolonged mechanical ventilation.

INTERVENTIONS

Prospective patients surveillance and data collection.

MAIN OUTCOME MEASURES

ICU mortality and multiorgan dysfunction.

RESULTS

Among 472 consecutive patients admitted to the cardiac surgery ICU following surgery, 107 (22.7%) required prolonged mechanical ventilation. Twenty-one of these patients (19.6%) died during their hospitalization. In a logistic-regression analysis, the development of an organ system failure index (OSFI) of 3 or greater was the only characteristic independently associated with ICU mortality (p < 0.001). The occurrence of an antibiotic-resistant infection (adjusted odds ratio [AOR] = 6.1, 95% confidence interval [CI] = 2.5 to 14.6 p = 0.006), an aortic cross-clamp time equal to or greater than 1.25 h (AOR = 3.9, CI = 2.3 to 6.8, p = 0.016), the development of ventilator-associated pneumonia (AOR = 3.6, CI = 2.4 to 5.3, p < 0.001), and an APACHE III score equal to or greater than 30 (AOR = 3.1, CI = 1.8 to 5.3, p = 0.036) were independently associated with the development of an OSFI of 3 or greater.

CONCLUSIONS

These data confirm that acquired multiorgan dysfunction is the best predictor of mortality in patients requiring prolonged mechanical ventilation following cardiac surgery. Additionally, they identify potential determinants of multiorgan dysfunction and suggest possible interventions for its reduction in this patient population.

Drug use evaluation of antibiotics in a pediatric teaching hospital

OBJECTIVE

To determine the incidence and type of antibiotic use variances at our institution.

DESIGN

Inpatient bacterial culture and susceptibility results were reviewed for 1 week per month. Medication administration records were evaluated to determine whether antibiotic selection was appropriate, given the susceptibility of the organism. Process indicators included use of the least costly antibiotic, as well as appropriate dose, interval, and route of administration. The complete medical record was reviewed for all patients if management did not appear to meet criteria.

SETTING

A 225-bed, tertiary-care children's teaching hospital.

RESULTS

Thirty-five (8.2%) of 428 patients reviewed over 12 months had a total of 49 variances: failure to treat (3), treatment of contaminant/colonizer (2), use of more costly agent (10), failure to revise therapy (8), inappropriate route (2), inappropriate empiric antibiotic (4), incorrect dose (3), unnecessary multiple antibiotics (6), inappropriate drug (8), and prolonged prophylaxis (3).

CONCLUSIONS

Thirty-five patients with 10 types of variances were identified during the study. Follow-up monitoring will assess the impact of educational efforts on the incidence of variances. Specific problem antibiotics have been identified for further audits.

Formulary control of antimicrobial usage. What price freedom?

Formulary controls are the most common and probably the most effective method for controlling abuse of antimicrobial agents in hospitalized patients. Such programs may include restriction of both the number of agents available and the way these agents may be used. These programs have been demonstrated to control pharmacy expenditures. Other potential advantages include reductions in the incidence of adverse drug reactions and the antimicrobial resistance among the hospital flora, and improvements in the overall quality of prescribing of antimicrobials. There are few data to document such benefits, however. Potential disadvantages are also poorly documented but include inconvenience for prescribing physicians, increased administrative costs, prescribing errors, and increased antimicrobial resistance. Antimicrobial control programs will likely remain common, but the availability of new information technologies should enable a transition to systems based on concurrent assessment of antimicrobial appropriateness with immediate feedback to the prescribing physician.