6. Sepsis and Infective Endocarditis Flashcards
Definition of bacteraemia
Transient presence of bacteria in the bloodstream
Definition of septicaemia
Persistent presence of bacteria in the bloodstream with attendant signs and symptoms
Definition of sepsis
Infection and SIRS
SIRS with a presumed/confirmed infectious process
Definition of SIRS
Systemic inflammatory response syndrome
A clinical response arising from a non-specific insult
Clinical features of SIRS (4)
Temperature <36C or >38C
HR/pulse >90bpm
Respiratory rate >20bpm or PaCO2 < 4.3pKa
WCC <4,000cells/mm3 or >12,000cells/mm3
Types of sepsis (3)
Sepsis
Severe sepsis
Septic shock
Definition of severe sepsis
Sepsis with one or more signs of organ dysfunction/failure (includes microvascular opening/rash)
Types of organ failure (7)
Cardiovascular (refractory hypotension) Renal Respiratory Hepatic Haematological CNS Metabolic acidosis
Definition of septic shock
Sepsis plus shock refractory to fluid resuscitation
What is sepsis (2)
Uncontrolled, unregulated, self-sustaining intravascular inflammation
Involves a cytokine storm
Definition of cytokine storm (2)
Unregulated simultaneous release of pro-inflammatory and anti-inflammatory elements out of balance
Extending to otherwise normal tissue
Reactions to sepsis
Endothelial damage
Microvascular dysfunction
Impaired tissue oxygenation
Organ injury
Gram negative septicaemia clinical features result from
Endotoxin release
Mainly hospital-acquired (E. coli)
Gram positive septicaemia clinical features result from
Teichoic acid and peptidoglycan from cell wall
Sources of infection (4)
Skin
Respiratory tract
Bone/joint infections
Oral cavity
Who does fungal septicaemia affect
Immunosuppressed hosts (disease of the diseased)
Septicaemia treatment (3)
Aggressive early treatment (IV antibiotics, oxygen, blind empirical antibiotics)
Modify treatment when culture available
Identify and remove source
Septicaemia diagnosis (4)
Blood cultures
Cultures of other infected sites
Detection of microbial products in serum
Molecular methods (PCR)
Sepsis 6 (6)
Give O2 to keep SATS >94% Take blood cultures Give IV antibiotics Give fluid challenge Measure lactate Measure urine output
Sepsis 6 - Why should you give O2 to keep SATS >94%
To maintain oxygen supply to organs, decreasing risk of failure
Sepsis 6 - Why should you take blood cultures
To identify source of infection and pathogen causing it
Sepsis 6 - Why should you give IV antibiotics
To get rid of the infection-causing pathogen
Sepsis 6 - Why should you give fluid challenge
Maintain hydration - challenge patient to drink certain amount
Sepsis 6 - Why should you measure lactate
Measurement of tissue dysfunction
Sepsis 6 - Why should you measure urine output
Measurement of metabolism of tissue and organs (urea conc.)
Definition of infective endocarditis
Microbial infection of the endothelial lining of the heart
Manifestation of infective endocarditis
Vegetations on heart valves, involves microbial colonisation of thrombi on surface irregularities
What does infective endocarditis cause
Haemodynamics and blood flow of heart to change, allowing bacteria to enter blood and accumulate in valves
Treatment of infective endocarditis
Surgical valve removal and prosthetic heart valve insertion
Problems with prosthetic heart valve
More suitable site for pathogens to adhere to
Infective endocarditis portals of entry (3)
Oral cavity
Skin breach
Haematological spread
Patients at higher risk of infective endocarditis (6)
Acquired valve disease Prosthetic valve Structural congenital heart disease Previous endocarditis Hypertrophic cardiomyopathy Recurrent bacteraemia
Infective endocarditis diagnosis (4)
Clinical signs
Blood cultures (x3 over 24hrs)
Echocardiography
DUKE criteria (positive micro blood cultures, evidence of endocardial involvement)
Infective endocarditis antimicrobial treatment (4)
Broad-spectrum initially, guide by lab results
Consider multiple drug combo
Monitor drug levels
Cardiac monitoring
