Electronic antibiotic stewardship--reduced consumption of broad-spectrum antibiotics using a computerized antimicrobial approval system in a hospital setting

OBJECTIVES

Antibiotic stewardship is important, but the ideal strategy for providing stewardship in a hospital setting is unknown. A practical, sustainable and transferable strategy is needed. This study evaluates the impact of a novel computerized antimicrobial approval system on antibiotic-prescribing behaviour in a hospital. Effects on drug consumption, antibiotic resistance patterns of local bacteria and patient outcomes were monitored.

METHODS

The study was conducted at a tertiary referral teaching hospital in Melbourne, Australia. The system was deployed in January 2005 and guided the use of 28 restricted antimicrobials. Data were collected over 7 years: 5 years before and 2 years after deployment. Uptake of the system was evaluated using an in-built audit trail. Drug utilization was prospectively monitored using pharmacy data (as defined daily doses per 1000 bed-days) and analysed via time-series analysis with segmental linear regression. Antibiograms of local bacteria were prospectively evaluated. In-hospital mortality and length of stay for patients with Gram-negative bacteraemia were also reported.

RESULTS

Between 250 and 300 approvals were registered per month during 2006. The gradients in the use of third- and fourth-generation cephalosporins (+0.52, -0.05, -0.39; P < 0.01), glycopeptides (+0.27, -0.53; P = 0.09), carbapenems (+0.12, -0.24; P = 0.21), aminoglycosides (+0.15, -0.27; P < 0.01) and quinolones (+0.76, +0.11; P = 0.08) all fell after deployment, while extended-spectrum penicillin use increased. Trends in increased susceptibility of Staphylococcus aureus to methicillin and improved susceptibility of Pseudomonas spp. to many antibiotics were observed. No increase in adverse outcomes for patients with Gram-negative bacteraemia was observed.

CONCLUSIONS

The system was successfully adopted and significant changes in antimicrobial usage were demonstrated.

A prospective comparison of severity scores for identifying patients with severe community acquired pneumonia: reconsidering what is meant by severe pneumonia

BACKGROUND

Several severity scores have been proposed to predict patient outcome and to guide initial management of patients with community acquired pneumonia (CAP). Most have been derived as predictors of mortality. A study was undertaken to compare the predictive value of these tools using different clinically meaningful outcomes as constructs for "severe pneumonia".

METHODS

A prospective cohort study was performed of all patients presenting to the emergency department with an admission diagnosis of CAP from March 2003 to March 2004. Clinical and laboratory features at presentation were used to calculate severity scores using the pneumonia severity index (PSI), the revised American Thoracic Society score (rATS), and the British Thoracic Society (BTS) severity scores CURB, modified BTS severity score, and CURB-65. The sensitivity, specificity, positive and negative predictive values were compared for four different outcomes (death, need for ICU admission, and combined outcomes of death and/or need for ventilatory or inotropic support).

RESULTS

392 patients were included in the analysis; 37 (9.4%) died and 26 (6.6%) required ventilatory and/or inotropic support. The modified BTS severity score performed best for all four outcomes. The PSI (classes IV+V) and CURB had a very similar performance as predictive tools for each outcome. The rATS identified the need for ICU admission well but not mortality. The CURB-65 score predicted mortality well but performed less well when requirement for ICU was included in the outcome of interest. When the combined outcome was evaluated (excluding patients aged >90 years and those from nursing homes), the best predictors were the modified BTS severity score (sensitivity 94.3%) and the PSI and CURB score (sensitivity 83.3% for both).

CONCLUSIONS

Different severity scores have different strengths and weaknesses as prediction tools. Validation should be done in the most relevant clinical setting, using more appropriate constructs of "severe pneumonia" to ensure that these potentially useful tools truly deliver what clinicians expect of them.

Detection of an aberrant motile larval form in the brain of a patient with neurocysticercosis

Neurocysticercosis is the most common parasitic infection of the central nervous system in humans. The adult pork tape worm, Taenia solium, resides in the lumen of the intestine, and the only structural element of an adult worm usually found within a tissue cyst in the brain or in muscle is a single invaginated scolex. We report a highly unusual, and perhaps unique, occurrence of neurocysticercosis in which an aberrant worm-like larval form, 12.5 cm in length, was found within a cyst in brain parenchyma.

A large localized outbreak of Mycobacterium ulcerans infection on a temperate southern Australian island

Mycobacterium ulcerans, the organism which causes Buruli or Bairnsdale ulcer, has never been isolated in culture from an environmental sample. Most foci of infection are in tropical regions. The authors describe the first 29 cases of M. ulcerans infection from a new focus on an island in temperate southern Australia, 1992-5. Cases were mostly elderly, had predominantly distal limb lesions and were clustered in a small region in the eastern half of the main town on the island. The authors suspected that an irrigation system which lay in the midst of the cluster was a source of infection. Limitation of irrigation was associated with a dramatic reduction in the number of new cases. These findings support the hypothesis that M. ulcerans has an aquatic reservoir and that persons may be infected directly or indirectly by mycobacteria disseminated locally by spray irrigation.

Helicobacter cinaedi bacteraemia: varied clinical manifestations in three homosexual males

We report 3 cases of Helicobacter cinaedi bacteraemia in different hosts representing a spectrum of clinical illness associated with this infection. The first was an AIDS patient with relapsing H. cinaedi bacteraemia despite antibiotic treatment. The second was an HIV seronegative homosexual man with end-stage renal failure, receiving haemodialysis and a previous history of chronic lymphoedema of his legs. He developed H. cinaedi bacteraemia with cellulitis of his left leg. Patient 3, an HIV seronegative homosexual man, had transient H. cinaedi bacteraemia 2 days after the completion of a course of chemotherapy for bilateral testicular carcinoma. The clinical spectrum of disease associated with H. cinaedi is broad, with few specific clinical features. Successful recovery of this fastidious organism from blood aids in the diagnosis of this unusual infection.

Hepatitis B vaccination and booster in predialysis patients: a 4-year analysis

Patients undergoing chronic haemodialysis are at increased risk for infection with hepatitis B virus (HBV), but response to currently available vaccines is suboptimal. We undertook a 4-year prospective study of the efficacy of hepatitis B vaccine in patients with renal insufficiency, who were not yet dialysis-dependent. A booster dose of Recombivax HB was given at 3 or 4 years to those whose antibody levels fell below a predetermined point. Progression to dialysis was associated with poorer initial response to vaccination compared with those remaining dialysis-independent, but response to booster immunization was favourable in both groups. It is concluded that immunization of predialysis patients and subsequent booster vaccine results in a more favourable antibody response than has been seen historically in haemodialysis patients. Local endemicity and cost of vaccine should be considered when determining the best strategy for HBV immunization of patients with chronic renal failure.

Persistence of antibody in healthcare workers vaccinated against hepatitis B

A cross-sectional serological survey was undertaken in 82 randomly selected high-risk healthcare workers previously vaccinated with the hepatitis B vaccine. The study design allowed for the identification and testing for hepatitis B surface antibody in equal numbers of employees in six-month intervals up to five years after vaccination. The results showed a consistent decline in antibody level with time, and an increasing proportion of participants with antibody levels below the commonly accepted protective level of greater than or equal to 10 S/N (sample counts/negative control counts) radioimmunoassay units. The percent of vaccinees whose S/N ratio was greater than 10 fell from 10% at one year, to 25% at two years, to over 50% at four years. Based on these figures, as well as the financial costs of hepatitis B in employees and the predictability of booster immunization, it was possible to assess the cost benefit of a hospital policy for reimmunization. At our institution, a strategy of revaccination at fixed intervals could save up to $200,000 over a ten-year period if revaccination was not offered and vaccine efficacy declined. The information obtained should help determine the need for revaccination and the advantages and disadvantages of alternative revaccination strategies.

Viral hepatitis. An important sexually transmitted disease

Hepatitis B is an important sexually transmitted disease. The availability of a safe and effective vaccine has unfortunately had little impact on controlling this disease nationwide or in North Carolina, chiefly because target groups have proven difficult to reach. Both HAV and NANB can be transmitted sexually, but are much less important than HBV.

Experience with trimethoprim-sulfamethoxazole in treatment of infective endocarditis

The published experience with trimethoprim-sulfamethoxazole (TMP-SMZ) for treatment of infective endocarditis was reviewed. Among 62 cases, a high proportion had unusual causative organisms: 60% of cases were due to Coxiella burnetii or Pseudomonas species. Only 17% of patients had previously normal cardiac valves. Patients often had complicated courses in which TMP-SMZ was tried only after other treatment regimens had failed, yet a successful outcome was achieved in 61% of cases. Thirty-five patients were treated with antibiotics alone, while the other 27 patients required combined medical and surgical management. TMP-SMZ has a limited role in the management of infective endocarditis; specific guidelines for its use, including proper laboratory control, have been delineated.