Infective Endocarditis (IE)

Question 1

WHERE in the heart can IE be CONTRACTED?

Answer 1

Infection of:

1) Valves - Native or Prosthetic
2) Endocardium
3) Interventricular Septum, i.e. Septal Defect
4) Intra-Cardiac Devices
5) Chordae Tendinae

Question 2

What are the some of the RISK FACTORS of IE?

Answer 2

1) Valvular Disease
2) > Age
3) Congenital Defects
4) Rheumatic Fever
5) Healthcare-Associated Infection
6) Invasive Procedures
7) Intra-Cardiac Devices
8) IV Drug Abuse (IVDA)
9) Immunocompromised Patients
10) Diabetes

Question 3

Describe the PATHOPHYSIOLOGY of IE:

Answer 3

1) Damage or Inflammation of Endothelial Lining
2) Adherence + Colonisation of Bacteria to Fibrin-Platelet Clot
3) Inflammatory Mediators Mobilised
4) Activation of Coagulation Cascade
5) Vegetation Growth

Question 4

How can BACTERAEMIA occur and spread?

Answer 4

1) Extra-Cardiac Infections
2) Invasive Procedures
3) Gingival Disease
4) Activities of Daily Living, i.e. Brushing Teeth

Question 5

What are the SYMPTOMS of IE?

Answer 5

*Can be Variable and Non-Specific

1) Fever
2) Fatigue
3) Malaise

Question 6

What is the MAIN CAUSE of IE?

Answer 6

Bacteraemia

Question 7

What are some of the IMMUNE COMPLEX DEPOSITION SIGNS of IE?

Answer 7

1) Splinter Haemorrhages
2) Janeway Lesions
3) Roth Spots
4) Osler’s Nodes
5) Vasculitis Rash

Question 8

What are some of the SEPTIC SIGNS of IE?

Answer 8

1) Pyrexia
2) Weight Loss
3) Night Sweats
4) Rigors
5) Anaemia
6) Splenomegaly
7) Clubbing

Question 9

What are the potential SIGNS of IE due to CARDIAC LESIONS?

Answer 9

Change to Pre-Existing or New Murmurs

Question 10

What are the OTHER potential SIGNS of IE?

Answer 10

1) Embolic Phenomena - PEs/Abscesses or Peripheral Emboli/Abscesses
2) Focal Neurological Signs

Question 11

Under what CIRCUMSTANCES may SIGNS of IE be ABSENT?

Answer 11

1) In the Elderly
2) After Antibiotic Treatment
3) < Virulent/Atypical Organisms
4) Immunocompromised

Question 12

What INVESTIGATIONS should be carried out to DIAGNOSE IE?

Answer 12

1) FBC - U + Es; Neutrophilia; CRP; ESR
2) Blood Cultures
3) Urinalysis
4) ECG
5) CXR
6) Echo - Transthoracic (TTE) + or - Transoesophageal (TOE)

Question 13

What is the MAIN CRITERIA for BLOOD acquisition and subsequent CULTURING when diagnosing IE?

Answer 13

Obtain:

1) Prior to Commencing Antibiotics
2) 3 Sets
3) From Different Sites
4) > 6 Hours Apart

Question 14

What might be evident on CXR for IE?

Answer 14

1) Congestive Heart Failure

2) PEs/Abscesses

Question 15

What is the FIRST-LINE MODE of echocardiography for IE?

Answer 15

TTE

*Perform TOE if TTE is -ve; yet, > Clinical Suspicion Remains

Question 16

What are the MAIN PATHOGENS involved in IE and are likely to return +ve in BLOOD CULTURES?

Answer 16

1) Streptococci - Strep. Viridans and Bovis
2) Enterococci
3) Staphylococci - Staph. Aureus and Epidermidis

Question 17

What would be the REASONS for a -ve BLOOD CULTURE RESULT in IE?

Answer 17

1) Prior Antibiotic Treatment
2) Fastidious Organisms - i.e. Gram -ve Bacilli or Fungi
3) Intracellular Bacteria

Question 18

What are the MAJOR CRITERIA for diagnosing IE according to DUKE CRITERIA?

Answer 18

1) Identification of an Organism via +ve Blood Cultures

2) Evidence of Infection in the Heart via Echo or Murmurs

Question 19

What are some of the MINOR CRITERIA for diagnosing IE according to DUKE CRITERIA?

Answer 19

1) Predisposition
2) Pyrexia
3) Vascular Phenomena, i.e. Emboli
4) Immunological Phenomena, i.e. Osler’s Nodes

Question 20

In order to obtain a DEFINITE diagnosis, which criteria MUST BE FULFILLED?

Answer 20

1) 2 Majors
2) 1 Major + 3 Minors
3) 5 Minors

Question 21

What are the TREATMENTS for IE?

Answer 21

1) IV Antibiotics *After Blood Cultures

2) + or - Surgery

Question 22

If IE pertains to NATIVE VALVES, which ANTIBIOTICS should be given?

Answer 22

*For 4 Weeks

Gentamicin + Amoxicillin

Question 23

If IE pertains to NATIVE VALVES and PENICILLIN ALLERGIC, which ANTIBIOTICS should be given

Answer 23

*For 4 Weeks

Gentamicin + Vancomycin

Question 24

If IE pertains to PROSTHETIC VALVES, which ANTIBIOTICS should be given?

Answer 24

*For 6 Weeks

Gentamicin + Vancomycin + Rifampicin

Question 25

What are some of the COMPLICATIONS of IE; thus, INDICATIONS for SURGERY?

Answer 25

1) Heart Failure
2) Leaflet Perforation
3) Uncontrolled Infection
4) Abscess Formation
5) AV Heart Block
6) Embolism
7) Prosthetic Valve Dysfunction/Dehiscence

Question 26

What does the EVIDENCE SUGGEST regarding the use of PROPHYLACTIC ANTIBIOTICS to prevent IE?

Answer 26

1) Unfounded Effectiveness
2) Should be Avoided
3) Limit to > Risk Patients
4) > Risk of Anaphylaxis
5) > Prevalence of Antibiotic Resistance

Question 27

What PREVENTATIVE GUIDANCE should be OFFERED to AVOID IE in those at risk?

Answer 27

1) Benefits and Risks of Prophylaxis
2) Good Oral Health
3) Symptoms that Indicate IE
4) When to Seek Expert Advice
5) Risks of Invasive Procedures; Including Non-Medical, i.e. Piercing or Tattooing