Blood Infections Flashcards
What is the treatment of community-acquired septicemia?
FIRST LINE:
A broad-spectrum antipseudomonal penicillin
- piperacillin + tazobactam
- ticarcillin + clavulanic acid
OR
A broad-spectrum cephalosporin
- cefuroxime (2nd gen)
- add second agent in specific cases:
- if MRSA is suspected, add vancomycin or teicoplanin
- if ANAEROBIC infection is suspected, add metronidazole to cephalosporin
- if other resistant organism is suspected, use broad-spec beta-lactam antibacterial eg meropenem (like hospital-acquired regimen)
What is the treatment of hospital-acquired septicemia?
FIRST LINE
A broad-spectrum antipseudomonal beta-lactam antibacterial, EITHER:
- piperacillin + tazobactam
- ticarcillin + clavulanic acid
- ceftazidime
- imipenem + cilastatin
- meropenem
- *add second agent in specific cases:
- if MRSA is suspected, add vancomycin or teicoplanin
- if anaerobic infection suspected, add metronidazole to broad-spec cephalosporin
(compared to community-acquired septicemia, this extends coverage to include more gram negative and anaerobic infectious agents)
What are the microorganisms most commonly implicated in community-acquired septicemia? (5)
GRAM POSITIVES:
Staphylococcus aureus
Streptococcus pneumoniae
GRAM NEGATIVES:
Pseudomonas aeruginosa
Escherichia coli
FUNGAL
Candida
(However, varies widely by region, season, patient demographics)
What are the most common sites of infection for patients with septicemia? (4)
- Lungs
- Abdomen
- Bloodstream
- Renal or GU tract
How is community-acquired septicemia differentiated from hospital-acquired?
The cut-off is typically between 48-72 hours:
- an infection is considered community-acquired if symptoms start within 48-72 hours of hospital admittance in an infected patient without recent exposure to healthcare risks
- symptoms that develop > 48-72 hours are more likely to be hospital acquired
**this distinction is important because it gives a clue to the etiological agent and therefore directs management
What is the difference between septicemia and sepsis?
SEPTICEMIA may lead to SEPSIS
- septicemia: life-threatening bacterial bloodstream infection, “blood poisoning” by bacteria
- sepsis: body’s response to septicemia which causes an extreme immune response and potentially dangerous whole-body inflammation that can lead to tissue damage, organ failure, and death (overwhelming and life-threatening RESPONSE to infection)
What microorganisms are most commonly implicated in nosocomial septicemia? (7)
- Aerobic gram-negative bacilli (E.coli, Klebsiella, Serratia marcescens)
- Anaerobes (Bacteroides fragilis, Fusobacterium, Lactobacillus, Clostriudium sp., Actinomyces)
- Candida sp.
- Staph aureus
- Enterococcus sp.
- Pseudomonas aeruginosa
- Staphylococcus sp.
https: //www.atsu.edu/faculty/chamberlain/website/lectures/lecture/sepsis2007.htm
https: //www.ncbi.nlm.nih.gov/books/NBK482349/
What organisms are targeted by piperacillin+tazobactam (Zosyn)? (3)
Coverage includes:
- Gram negative organisms including Pseudomonas
- Gram positives
- Anaerobic bacterial organisms (Bacteroides fragilis, Fusobacterium, Lactobacillus, Clostriudium sp., Actinomyces)
What are the main anaerobic organisms implicated in bacterial infection? (5)
- Bacteroides fragilis
- Fusobacterium
- Lactobacillus
- Clostriudium sp.
- Actinomyces
What is the coverage of carbapenems meropenem and imipenem?
In general, all carbapenems are considered broad spectrum, providing good coverage against gram positive, gram negative, and anaerobic organisms.
Meropenem: more active against gram-negative bacilli (eg Pseudomonas, E.coli, Klebsiella, Enterobacter, Serratia, etc)
Imipenem: more active against gram-positive cocci (strep, staph)
**they do NOT cover Enterococcus faecium or MRSA
What is the coverage of ticarcillin + clavulanic acid? (Co-ticarclav)
Broad spectrum: covers gram-positive, gram-negative, aerobic and anaerobic bacteria
What is the coverage of ceftazidime?
Ceftazidime is a THIRD generation cephalosporin with coverage against:
- gram-negative aerobes (Enterobacter, E.coli, H.influenza, Klebsiella, Proteus, P.aeruginosa, N.meningitidis)
- gram-positive aerobes (GBS, Strep pneumo, Strep pyogenes)
**generally has poor activity against anaerobes eg Bacteroides
List the main gram-negative aerobic bacteria (7)
- Enterobacter
- E.coli
- H.influenza
- Klebsiella
- Proteus
- Pseudomonas
- Neisseria meningitidis
(vs anaerobes:
- gram-positive: Lactobacillus, Clostriudium sp., Actinomyces
- gram-negative: Bacteroides fragilis, Fusobacterium)
What is the treatment of septicemia related to a vascular catheter?
FIRST LINE:
Vancomycin or teicoplanin
In special cases:
- if gram-negative sepsis suspected (especially if immunocompromised), add a broad-spectrum antipseudomonal beta-lactam
- consider removing vascular catheter if infection is caused by staph, pseudomonas, or candida
What is the treatment of meningococcal septicemia?
If meningococcal disease is suspected:
FIRST LINE:
Single dose of benzylpenicillin sodium given immediately (before urgent transfer to hospital as long as it does not delay transfer)
SECOND LINE:
Cefotaxime (if penicillin allergy)
THIRD LINE:
Chloramphenicol (if history of allergy to penicillin or cephalosporins)
