How do we make decisions? (In medicine)

How do we make decisions? In medicine

• Dogma:” Doctrine/Teaching”

• Tradition: “We’ve always done it that way”

• Convention: “Everyone does it this way”

• Evidence-Based: “Evidence supports this way”

Evidence Based Medicine(EBM)

• Conscientious, ^yDoh idÌshg wkql+,&• Explicit, ^iqmeyeos,s&• Judicious ^m%{djkA;&

• use of

• “current best evidence in making decisions about the care of individual patients”

Infective Endocarditis:Approach to

Evidence Based Management

BSAC Guidelines

Contents

• First BSAC guidelines- in 2004- Mostly the expert opinions

• Latest in 2012 – – Majority of recommendations are evidence

based,– Rest are consensus among the working party

members (Expert Opinion)

What is included in 2012 BSAC

• Mx of Native valve endocarditis(NVE) &

• Mx of Prosthetic valve endocarditis (PVE).

• PVE includes infections in– Prosthetic valves of all types,– Annuloplasty rings, – Intracardiac patches and – Shunts.

What is excluded from 2012

• Infective Endocarditis related to – pacemakers, – defibrillators or– ventricular-assist devices

• These dealt in a separate BSAC review

The aim of these guidelines

• Standardize the initial investigation and treatment of IE;

• Identify the patients who can develop adverse drug reactions (Side Effects and Toxicity)

• identify pts fail to respond to initial antimicrobial therapy and may require a change in therapy or surgery.

Summary2004 Vs 2012

• 2004 guidelines based on expert opinion

• 2012 – Mostly are evidence based: When evidence is not available→ Consensus– A-high-quality randomized controlled trials and

meta-analysis of randomized controlled trials; – B -observational data and non-randomized trials;

and – C - expert opinion or Working Party consensus.

Level of evidence gradation according to strength of evidenceC<B<A

Some Facts of IE

IE- The clinical presentation is highly variable,

• Vary according to the causative microorganism,

• Vary according to presence or absence of pre-existing cardiac disease,

• Presence of co-morbidities

• Risk factors for the development of IE.(IVDU,HD, etc)

IE may present as

• An acute, rapidly progressive infection,

• as a subacute or chronic disease,

• low-grade fever and non-specific symptoms that may cause confusion in initial assessment.

• Patients present to a variety of specialists/GPs who may consider a range of alternative diagnoses, – Any chronic infection, – Rheumatological disorder– and autoimmune disease or – malignancy.

Presentation• The majority (90%) of patients present with fever,

– with systemic symptoms of chills, – poor appetite– weight loss.

• Heart murmurs up to 85% (Pre existing heart murmur should prompt heighten degree of suspicion for look for IE)

• New murmurs reported in 48%.

• New valvular regurgitation is more specific for a diagnosis of IE

• Classic textbook signs( Rare)

• Peripheral stigmata of IE are increasingly uncommon (patients generally present at an early stage of the disease)

• Immunological phenomena, such as – Splinter hemorrhages, – Roth spots and– glomerulonephritis, are now less common,

• Emboli to brain, lung or spleen occur in 30% of patients(Often could be presenting symptom)

Six right sided endocarditis patients were followed up….

Present/Yes Absent/No Total

Embolic phenomena

3Pneumonia

3 6

Isolate MRSA (3 out of 3 sets) 3 patients

3 6

Risk factor Present in 3 cases1. CVP cannulation @

ICU 3/12 before for MX of DHF

2. Recurrent Blood transfusion for Thal

3. Criminal Abortion4. Long Term HD5. Long Term HD

Risk factors not present in one case

6

Classical risk factors such as IVDU

No Not present in all 6 case 6

Outcome with surgery

3 responded for vegetectomy

one died and 1 responded for treatment, one undergoing treatment

6

• Atypical presentations– e.g. absence of fever is more common in the elderly,

after antibiotic pre-treatment, – in the immunocompromised patients and – in IE involving less virulent or atypical organisms.

• The diagnosis of IE should also be considered in patients who present with – a stroke or transient ischaemic attack and a fever.

BSAC Guidelines

Clinical Assessment and

diagnosis

Summary of ECHO Recommendation of IE

The Duke criteria has clinical, echocardiographicand microbiological findings,

Were developed as a research tool- provide high specificity and moderatesensitivity for the diagnosis of IE.

These criteria an objective tool for evaluating the strength of evidence to support a diagnosis of IE, particularly in difficult cases.

Microbiological Diagnosis & AST

IE is a condition where you get continuous bacteremia

• Generally all three blood cultures will be positive

• Single blood culture = No culturing

WE have stopped giving sensitivities on the isolates directly to the wards. AST should be interpreted with the help of CLIN_MICRO TEAM

Culture Negative Infective Endocarditis

Role of Serology

Role of surgery in

infective endocarditis

Antibiotic Dosing Delivery

and Monitoring

Why monitor only aminoglycosides (and Vancomycin?)

• Low therapeutic index.

• Bactericidal efficacy ᾀ peak concentrations

• Toxicity is related to total drug exposure

• Nephrotoxicity (usually reversible) and ototoxicity (often irreversible)

• The desired plasma concentration-time profile for aminoglycosides differs to most other drugs.

Amino glycoside toxicity

• More with divided doses than single once daily dose

• Body weight is measured according to ideal body weight (not the actual body weight)

• Ideal body weight ± 20% is allowed

Monitoring For Aminoglycosides and Vancomycin levels- THK Protocol

• RECEIVE THIS FROM MICRO DEPARTMENT

Use of Ɓ-Lactams

• Can amphicillin/amoxycillin use fro treatment of IE• Why only penicillin is used?

• What are the drugs given in pen allergy?• How do you ascertain a history of pen allergy as a true

immediate type of HS?

• With a history of rash with Amp, can you give pen?

• In the backdrop of anaphylaxis, can you give CRO?

5.3 b-Lactams• Amoxicillin and ampicillin → microbiologically equivalent and either

can be used.

• Amoxicillin can be used instead of benzylpenicillin for susceptible isolates (greater risk of Clostridium difficile infection)

• Need to be given more frequently (due to short t1/2)

• No comparison of continuous with intermittent penicillin administration for streptococcal endocarditis.

• Dose modifications necessary for renal failure

A history of a rash with ampicillin or amoxicillin may not indicate true allergy. Unless signs of immediate-type hypersensitivity (anaphylaxis, angio-oedema, bronchospasm and urticaria) were reported, a trial with penicillin may be warranted,(A emergency trolley need to be kept bear)

A rash occurs after 72 h- unlikely to be an immediate IgE-mediatedreaction (type I hypersensitivity).

In a recent study, 72% of patients with a delayed-type hypersensitivity reaction to aminopenicillins had no cross-reactivity with penicillin.

The American Heart Association (AHA) advises ceftriaxone for the penicillin-allergic pts, (for allergy other than immediate-type hypersensitivity, because of the risk of cross-sensitivity with penicillin)

5.5 Other antibiotics

• linezolid and daptomycin

• Only after consultating Micro Team