Synchronizing Antimicrobial Susceptibility Testing with Interdepartmental Goals and StrategiesAPRIL ABBOT T, PH.D. , D(ABMM)

DEACONESS HEALTH SYSTEM

EVANSVILLE, IN

APRIL.ABBOT T@DEACONESS.COM

SCACM Audioconference October 3, 2017P.A.C.E.® # 362-008-17

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Objectives• Discuss the role of AST for infection control purposes

• Describe regulatory considerations and hospital incentives surrounding susceptibility data

• Discuss participation in and goals of antimicrobial stewardship programs

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The Real Role of the Clinical Microbiology Lab • Historically, the tasks of the Microbiology Laboratory were to isolate, identify and determine antibiotic susceptibility patterns of pathogens

• Today, personnel from Microbiology are asked to participate in hospital programs such as • Infection Prevention and Control

• Antimicrobial Stewardship

• Care conferences, interdisciplinary rounds

• Such programs exist to improve patient care, but also because of monetary incentives

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Affordable Care Act• Three separate programs created in 2010 with the goal of improving health care and reducing the cost of health care in the U.S.

• Monitor clinical outcomes◦ Value Based Purchasing

◦ Readmissions

◦ Hospital Acquired Conditions

• Penalize for poor performance (↓ $$)

• Incentivize (reward) for good performance (↑ $$)

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Value Based Purchasing/Programs

Who: Centers for Medicare/Medicaid Services (CMS) are a big driver in these programs, but hospitals likely participate in multiple value-based programs from other payers (e.g. Anthem, Aetna)

How: For participation in their healthcare plan, hospitals are required to submit certain data. Outcomes are measured and compared to national averages (benchmarks) to determine how a hospital is performing

What: The hospital then receives payment for care provided based on whether the hospital underperformed or outperformed

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Value Based PurchasingFour metrics◦ Clinical care (e.g. mortality, complications)

◦ Person and Community Engagement (e.g. HCAHPS scores)

◦ Safety (e.g. hospital acquired infections)

◦ Efficiency (e.g. spending per patient)

Each item is scored based on the national benchmark and improvement

Total Performance Score

The score in a given year to determine performance impact to payment is actually based on your performance two years prior

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Determining Your Score

Achievement

Improvement

Get the points of whichever is highest

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Overall Risk

• Overall, at risk of having 6% of payment withheld

• Distributed across the care of each CMS patient (i.e. get paid less for the care of each patient)

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Other Programs

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So What?

Key measures that Microbiology Impacts◦ CRE NHSN toolkit

◦ HAIs

◦ Antimicrobial usage

◦ Antimicrobial stewardship

◦ Length of stay

◦ Communication

Diekema, JCM, 2017, Vol. 55 (4)

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Hospital Acquired Infections

• Infections that are often associated with medical devices such as central line-associated blood stream infections (CLABSI) and catheter-associated urinary tract infections (CAUTI)

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CLABSI Case• Infection Prevention and Control (IPC) practitioner contacts the lab

• Patient with a central line is growing a single organism in 1 out of 4 sets with no clinical signs of sepsis

• Unusual organism that she has not seen the lab previously report: Dermabacter hominis, sent to reference laboratory for susceptibility testing

• The IPC officer wants to know if this patient possible got this organism from a source other than her central line

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Dermabacter hominis

• Gram positive bacilli, coryneform

• Catalase positive

• Small grayish-white colonies

• Pungent odor

• Present on skin

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CLABSI and Microbiological Advances• Until recently the isolation of coryneform bacteria in many types of clinical samples, including blood cultures, was usually considered synonymous with contamination

• With MALDI-TOF MS, laboratories are more readily able to provide a name, but should they??

• Dermabacter hominis has been associated with bacteremia and wound infections; however, it is also frequently isolated as a skin contaminant

• If using previously established criteria (pre-MALDI) the isolate would have been called a diphtheroid and a statement conveying the isolate is a likely contaminate would have been appended to the culture report

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Common Commensals List

Centers for Disease Control and Prevention. NHSN organism list. Centers for Disease Control and Prevention, Atlanta, GA. www.cdc.gov/nhsn/xls/ master-organism-com-commensals-lists.xlsx

• Dermabacter is on the list of common commensals

• What about the clinical significance of Actinomyces or bacteria that have undergone a recent name change when those are isolated in blood culture?

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• Only 10 of 60 patients with Actinomyces isolated from blood cultures were deemed to have a clinical suspicion for actinomycosis

• Majority of those patients where the physician felt the isolate did not represent a clinical infection were untreated. None had recurrence.

• Historically, Actinomyces have not been considered part of the normal microbiota; however, with recent improvements in identification methods, isolation of Actinomyces is occurring in patients with no clinical signs of infection

• Further complicated because taxonomists keep adding and changing names!!

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Handling Questionable “Coryneforms”

• Providing an identification when the significance of the organism is questionable• May lead to treatment of the patient that is unnecessary

• May result in claiming hospital acquired infection

• Establish reporting rules in concert with physician and IPC input

• For example, when organism is identified in only one set, consider• Reporting the organism but add a comment labeling it as a “diphtheroid” or

“diphtheroid-like” organism, possible contaminant or clinical significance unknown

• Reporting as diphtheroid

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Reducing Cost for the Lab and the Hospital

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Reducing Unnecessary Testing (and Cost)• The laboratory is frequently the gate keeper for test utilization• Guide physicians on the appropriate test to order

• Report information in a manner to demonstrate clinical relevance

• Rules regarding the reporting of blood culture contaminants

• Only perform testing deemed to be clinically relevant

• Use Gram stain to assist in determining quality of the specimen

• Limit the amount of workup on heavily mixed cultures

• Only perform susceptibility testing on clinically relevant isolates

• The laboratory is often not reimbursed for testing performed

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CAUTI Case• IPC is concerned that they are seeing a high number of catheter-associated urinary tract infections (CAUTI) despite a number of initiatives to reduce this HAI

• The laboratory is asked to assist in the reduction of CAUTIs

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Lab-driven CAUTI Initiatives• Development of specimen collection materials

• Requirement for culture indication when ordering

• Urine transport device

• Urinalysis reflex to culture

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Transport TimeReject >24 hours

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Why Preserve Urine?

10 min 4 hr

Voided

CCMS

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UA Reflex to Culture Algorithm• Algorithms that promote utilizing urinalysis (UA) results to determine acceptability for urine culture limit overuse of urine culture orders, help control laboratory resources, reduce cost, and assist in antimicrobial stewardship

• Reducing urine culture ordering in catheterized inpatients can both reduce the NHSN-defined CAUTI rate and reduce unnecessary antibiotic use

• Not applicable for all patient populations (e.g. immunocompromised, pregnancy, urological procedures)

• Urine cultures are often obtained for inappropriate reasons (e.g. smelly urine)

• Common UA reflex criteria: leukocyte esterase (LE), nitrite, bacteria, WBCs

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The Literature on Urinalysis• No consensus as to what markers best predict UTI

• The negative predictive value of UA markers (i.e. all 4 are negative) is good with an estimated 4% false negative rate compared to culture alone.

• The positive predictive value of UA alone for diagnosis of UTI is low, necessitating culture. Overall, 22% of asymptomatic patients will have a positive UA (number varies by patient population and approaches 100% in chronically catheterized patients)

• Estimated that 23% -50% of antibiotic days for UTI are unnecessary treatment of asymptomatic bacteriuria

Garcia and Spitzer, AJIC, 2017

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Now You Have a Positive Urine Culture, What About AST

• Limit unnecessary workup – only report pathogens

• Consider evaluating the outpatient urine antibiogram to help determine optimal therapy

• Push physicians to use optimal therapy, but there are challenges• Fosfomycin

• Cefazolin urine breakpoints (E. coli, K. pneumoniae, P. mirabilis)

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Cefazolin to Predict Oral Cephalosporins• Cefazolin became the recommended surrogate marker for oral cephalosporins when treating uncomplicated UTIs in 2014

*Oral cephalosporins (cefaclor, cefdinir, cefpodoxime, cefprozil, cefuroxime, cephalexin, and loracarbef)

Test/ Report Group

Agent

MIC Breakpoint (µg/ml) Comments

Susc Int Res

Cephems (Parenteral)

A Cefazolin ≤2 4 ≥8based on dose of 2 g every 8 h

Cephems (Oral)

U Cefazolin* ≤16 - ≥32

M100-S27

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Why Urine-Specific Breakpoints• Many antibiotics concentrate in the urine

• Generally speaking, breakpoints are established based on the amount of drug that one can reasonably achieve in blood (and CSF) and do not necessarily correlate with the amount of drug one can achieve in other compartments, specifically urine

• Cefazolin was determined to be a great surrogate test for the oral cephalosporins – posses the ability to predict susceptibility to other agents without the need to test each independently

• Ultimately, the lowered cefazolin breakpoints (2010 to address ESBL testing) would result in reporting of cefazolin as resistant, thus excluding this treatment option for many UTIs that would respond to this agent

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How to Report: Example UTI vs Urosepsis• 65 year old female presents with uncomplicated UTI symptoms

• 65 year old female presents with UTI, but also symptoms of sepsis

Isolate 1: Urine MIC Interp

Cefazolin 8 S

Isolate 2: Blood MIC Interp

Cefazolin 8 R

Isolate 1: Urine MIC Interp

Cefazolin 8 S

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How to Communicate Results• Lab often does not know clinical scenario

• There is not a “urine cefazolin” breakpoint on a commercial AST system

• In the laboratory information system (LIS) build an additional agent and interpretations for urine isolates only

Urine Isolate MIC Interp

Oral cephs(uncomplicated UTI)

8 S

Cefazolin (parenteral) 8 R

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Antimicrobial Stewardship Effect

• When reviewing our antibiogram• E. coli all isolates demonstrated 70% susceptibility

• E. coli urine isolates demonstrated 95% susceptibility

• Urine specific antibiogram would allow for prediction of which agents would be most useful for empiric therapy in the outpatient setting (these are the patients most likely to have uncomplicated UTIs)

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More Assistance with Antimicrobial Stewardship

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Why Get Involved in Antimicrobial Stewardship

• Between 20-50% of antibiotic prescriptions are unnecessary or inappropriate

• Poor antibiotic selection contributes to mortality and morbidity

• Antibiotic use is the single most important risk factor for C. difficile infection

• Prolonged and non-judicious antibiotic use contributes to development of resistance

• At the end of the day, this is YOUR data!

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Antimicrobial Susceptibility Reports• Help clinicians to choose the most appropriate empiric and then definitive therapy• Empiric therapy = treatment before a definitive diagnosis

• Antibiogram

• Definitive therapy = treatment after the susceptibility pattern is known

• Individual organism susceptibility report

• Comments may be added to additional assist with clarification, to provide prescribing guidance without performing susceptibility testing (e.g. beta-hemolytic streptococci vs penicillin, to provide dosing information, etc.

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Case: Stewardship for Bloodstream Infections

• 72 year old female

• Arrives at ED with symptoms consistent with a urinary tract infection, but the patient is also experiencing possible altered mental status

• Both urine and blood cultures obtained

• Admitted to be further evaluated and placed on vancomycin and meropenem

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Coagulase negative staphylococci, likely

contaminant

1 hr ~18-24 hrs 4 hrs

~3 hrs

+

ID

S. epidermidis

Total ~24-30 hrs

Call & Pharmacy Consult

4 hours!!

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• Pharmacy note:

• Hospitalist note:

• Called by pharmacy. Blood cx came back 1 of 2 sets coag neg staph, likely contaminat. Pt evaluated, diagnosed with UTI, no clinical signs of sepsis or risk factors for CoNS sepsis. Stopped vancomycin

• SUCCESSFUL BECAUSE RESULTS ARE ACTED UPON. Must establish a mechanism for active communication of results, passively putting these into the patient record will not result in optimal success

Treatment Success – Removal of Unnecessary Antibiotic

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Other Considerations• Billing and reimbursement: • Charge for your work

• Routinely re-evaluate charges for your work

• Billing and collection errors = free work

• Work with billing department early and often

• Don’t forget about specialty populations (e.g. pediatrics, cystic fibrosis) and differences between inpatients and outpatients

• Interdisciplinary teams help to address problems before they become PROBLEMS

• Get involved to show your worth!

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Questions?

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