IE Flashcards
What is IE?
Infection of the endothelial layer of the heart wall causing inflammation
Why does IE also affect valves?
Valves are often in contact with the endothelium so infection spreads
Risk factors for IE?
IV drug abusers Males Heart surgery - valvular/prosthetics Dental work - poor dental hygiene Congenital heart issues affecting valves Rheumatic heart disease affecting valves
What gender has the worst prognosis?
Females
Why are IV drug abusers more at risk?
Breach of skin allows normal skin bacteria to enter bloodstream
Why are people with poor dental hygiene who go for dental work more at risk?
Dentist could cause a breach in mouth and bacteria such as strep which grows in mouth can enter bloodstream
What is the pathophysiology?
Bacteria infects endocardium and valves
Bacteria begin to multiply and cause “fibrin plated” vegetation on valves
Valves become calcified and decreases blood flow causing heart failure and fatigue
Valves also become thrombosed
How is vegetation detected?
Echocardiograms
What is a major problem with vegetation?
It can break off and cause emboli’s
What can occur if the emboli is in the right side of the heart?
Pulmonary embolism
What can occur if the emboli is in the left side of the heart?
Can enter the systemic circulation and maybe cause a stroke or infarct elsewhere
What is a common complication of IE?
Heart failure - if valves are destroyed
What happens to the blood flow out of the heart once valves have vegetation?
Becomes turbulent
What are the main symptoms?
Fever, chills - infection
Weight loss
Headache
MSK pain
Do previously damaged valves increase risk of IE?
Yes - makes it easier for bacteria to attach as there will be a thrombus formed on the sit of injury
What are some signs of IE that suggest immune complex deposition?
Splinter haemorrhages
Roth spots - retinal bleeds, white centre on retina
Oslers nodes - deep red painful spots on finger tips
Janeway lesions - Flat red spots on hands and soles of feet - escape of blood from ruptured vessel
Vasculitic rash - widespread small red/purple dots that don’t go away with compression
Nephritis
What are some other signs that suggest IE?
A new murmur
In what type of patient will signs be absent?
Elderly
Immuno-compromised
IE with less virulent/atypical bacteria
After a patient has had antibiotics
What is a major complication of IE?
Heart failure
What are the major signs of the duke criteria?
2 positive blood cultures for common organisms that cause IE
Echocardiogram shows positive vegetation
New murmur
What are the minor signs of the duke criteria?
Predisposing valvular condition or is an IVDA
Fever - over 38
Blood cultures that don’t meet the major criteria - shows an atypical organism
Immunologic phenomena
Vascular phenomena
What shows immunological phenomena?
Oslers nodes
Roth spots
Nephritis
What shows a vascular phenomena?
Arterial emboli
Janeway lesions
Intracerebral bleed
Conjunctival bleed
How is IE diagnosed using the Duke criteria?
2 major
5 minor
1 major and 3 minor
Either all major, all minor or 1 major 3 minors
What investigative tests can be done?
FBC
C-reactive protein and ESR test
Urea and Electrolytes
Blood culture
Urinalysis
ECG
CxR
Echo
What is the 1st line investigation and why?
Echos - to spot vegetation
Why is CRP and ESR tests done?
To test for inflammation
Why is a FBC done?
Check for raised neutrophil count for infection
How are blood cultures done?
Done BEFORE any antibiotics are given
3 sets at different sites of body
Done 6 hours in-between sets
How are blood cultures done if patient is in sepsis/shock and time is a major constraint?
2 sets with an hour in-between
What are the common organisms that cause infection?
Strep
Staph
Enterococci
What type of streps cause infection?
Oral strep
What types of staph cause infection?
Staph aureus
Staph epidermis
Coagulase negative staph
Name a type of enterococci that causes infection?
E. faecalis
What are some atypical infective causes?
Intracellular bacteria:
Coxiella Burnetii
Bartonella
Fastidious organisms:
HACEK group
Brucella
Fungi
What is a specific test for intracellular bacteria such as coxiella burnetii
Serological testing
PCR
How are echos undertaken?
A trans-thoracic echo is done (TTE) and if low clinical suspicion and test is normal leave it at that
If high clinical suspicion or TTE shows some IE do a trans-oesophageal (TOE) to see IE better
What is tested for in a CxR?
Heart failure
Pulmonary abscess
What does a urine test look for?
Blood - nephritis
Treatment?
Look at marty’s Ox handbook cards
