BACTEREMIA AND SEPSIS

Question 1

Symptoms that may reflect metastatic staph. aureus bacteremia

Answer 1

1. bone or joint pain (septic arthritis)
2. protracted fever, night sweats, murmur, heart failure (endocarditis)
3. abdominal pain, especially LUQ pain (splenic infarction)
4. CVA tenderness (renal infarct or PSOAS abscess)
5. HA, difficulty breathing, altered mental status (septic emboli)

Question 2

Clinical approach to SAB

Answer 2

1. physical exam - metastatic seeding may occur within the first few days of hospitalization but may not be clinically apparent for several weeks
2. infectious disease consult - decreased mortality, fewer relapses, and decreased readmission rates
3. repeat blood cultures q48-72h to document clearance - treatment day starts day of negative blood cultures

Question 3

Echocardiography

Answer 3

• TTE performed first in SAB -identifying vegetation size/location
• TEE usually performed after TTE (preferred for MRSA bacteremia) - identifying intracardiac abscesses and valve perforation
• most sensitive when performed 5-7 days after onset

Question 4

staphylococcus aureus in urine

Answer 4

• not common organism in UTIs

- translocation of S. aureus from blood to urine due to hematogenous seeding and development of micro-abscesses

Question 5

Catheter and prosthetic device management in SAB

Answer 5

-attempt to remove all prosthetic devices; if not, significant increase in risk of relapse
-if unable to remove may add rifampin and may need long-term suppressive therapy
short term catheters- remove asap
long term catheters- remove unless major CI
replace catheters when blood cultures are negative for 48-72 hrs

Question 6

Empiric treatment of SAB

Answer 6

1. prompt source control

2. empirically cover MSSA and MRSA: vancomycin or daptomycin

Question 7

Treatment of MSSA bacteremia

Answer 7

nafcillin, oxacillin, cefazolin

-DO NOT USE: vanocmycin, combination with rifampin, combination with aminoglycosides unless endocarditiis

Question 8

Treatment of MRSA bacteremia

Answer 8

Vancomycin or Daptomycin

• dapto can be used in patients with septic pulmonary emboli because the clot is inside the vasculature and there is no surfactant present
• addition of gentamicin or rifampin to vancomycin is not reccomended unless infective endocarditis with prosthetic heart valve

Question 9

Combination therapy for MRSA bacteremia

Answer 9

it may be reasonable to employ combination therapy with a PBP-1 active beta-lactam or ceftaroline with vanco or dapto early in MRSA bacteremia especially in patients at the highest risk of treatment failure and death

Question 10

Duration of treatment for SAB

Answer 10

• uncomplicated SAB 14 days of IV therapy from the first negative blood culture.
• complicated SAB 4-6 weeks

Question 11

criteria for uncomplicated SAB

Answer 11

• exclusion of endocarditis (negative TTE, TEE)
• no indwelling or implantable devices or prostheses
• follow-up blood cultures drawn 2-4 days after initiating IV therapy and removal of the presumed focus on infection are negative
• patient defervesced with 48-72 hours after initiating IV therapy and removal of the presumed focus on infection
• no evidence of metastatic infection

Question 12

Systemic inflammatory response syndrome (SIRS)

Answer 12

• systemic inflammatory response to a variety of severe clinical insults (infectious or non-infectious), manifested by 2 or more of the following conditions:
  1. temperature >100.4 (38C) or <96.8 (36C)
  2. HR > 90 BPM
  3. RR >20 BPM or PaCO2 <32 mmHg
  4. WBC >12000/mm3, <4000/mm3, or >10% immature (band) forms

Question 13

Septic shock

Answer 13

• subset of sepsis in which underlying circulatory, cellular, and metabolic abnormalities are associated with higher risk of mortality than sepsis alone
• patients requiring vasopressors to maintain a MAP 65 mmHg and serum lactate >2 mmol/L (>18 mg/dL) in the absence of hypovolemia

Question 14

Causative pathogens in sepsis and septic shock: gram (-)

Answer 14

1. enterobacteriacea (E. Coli, Klebsiella, Enterobacter, Serratia, Proteus)
2. enteric gram (-) bacteria - normal endogenous flora within the GI tract
3. integrity of the GI mucosa - mechanical barrier (trauma, penetrating wounds, ulcerations, mechanical obstruction, ischemia)
4. pseudomonas- mechanical ventilation, prolonged hospitalization, burn injury
5. acinetobacter (prior antibiotic exposure)

Question 15

Causative pathogen in sepsis and septic shock: gram (+)

Answer 15

1. staphylococci- associated with intravascular devices, artificial heart valves
2. S. pneumonia
3. enterococci - prolonged hospitalization treatment with cephalosporins

Question 16

Causative pathogen in sepsis and septic shock: fungi

Answer 16

1. C. albicans

2. C. glabrata, C. parapsilosis, C. trropicalis, C. krusei

Question 17

Procalcitonin in sepsis

Answer 17

Initiating antibiotic therapy
1. <0.25 ng/mL - antibiotics strongly discouraged
2. >0.25 and <0.5 ng/mL - antibiotics discouraged
3. >/= 0.5 and <1 ng/mL - antibiotics encouraged
>1 ng/mL - antibiotics strongly encouraged

Continuing or stopping antibiotic therapy

1. <0.25 ng/mL - stopping antibiotics strongly encouraged
2. > 0.25 and <0.5 ng/mL - stopping antibiotics encouraged
3. > 0.5 ng/mL - continuing antibiotics encouraged
4. > 0.5 ng/mL - changing antibiotics strongly encouraged

Question 18

Laboratory/diagnostic in sepsis and septic shock

Answer 18

1. blood cultures -at least 2 sets (aerobic and anaerobic)
2. specimens for direct examination and culture from any primary or metastatic site of infection
3. obtain before antimicrobial therapy if no significant delay
4. WBC with differential
5. coagulation tests
6. SCr, BUN, LFTs to determine organ dysfunction
7. imaging studies

Question 19

To be completed in the first 3 hours of presentation of sepsis/septic shock

Answer 19

1. measure lactate conc
2. obtain blood cultures prior to administration of antibiotics
3. administer broad-spectrum antibiotics
4. administer 30 mL/kg of crystalloid (NS or LR) for sepsis-induced hypotension or septic shock, or lactate >4 mmol/L

Question 20

To be completed in the first 6 hours of presentation of sepsis/septic shock

Answer 20

1. apply vasopressors (for hypotension not responding to fluid resuscitation) to maintain MAP > 65 mmHg - norepinephrine is the first line
   - if MAP is not at goal add vasopressin
   - if MAP not at goal with levo + vaso add epinephrine

Question 21

MAP calcualtion

Answer 21

MAP = systolic + 2 x diastolic / 3

Question 22

Empiric therapy for sepsis in adults with community-acquired infection in non-neutropenic patients (ANC > 1000/mm3): pneumonia

Answer 22

1. ceftriaxone + azithromycin

2. ceftriaxone + respiratory FQ (Moxi or Levo)

Question 23

Empiric therapy for sepsis in adults with community-acquired infection in non-neutropenic patients (ANC > 1000/mm3): UTI

Answer 23

1. 3rd or 4th gen cephalosporin (+/- aminoglycoside)
2. zosyn (+/- aminoglycoside)
3. FQ (cipro or levo)

Question 24

Empiric therapy for sepsis in adults with community-acquired infection in non-neutropenic patients (ANC > 1000/mm3): suspected intra-abdominal source

Answer 24

1. zosyn
2. carbapenem
3. 3rd or 4th gen cephalosporin + metronidazole
4. cipro or levo + metronidazole

Question 25

Empiric therapy for sepsis in adults with community-acquired infection in non-neutropenic patients (ANC > 1000/mm3): SSTI (cellulitis)

Answer 25

1. vancomycin 2. linezolid 3. daptomycin

Question 26

Empiric therapy for sepsis in adults with hospital-acquired infection in non-neutropenic patients (ANC > 1000/mm3): HAP/VAP

Answer 26

anti-pseudomonal beta-lactam + aminoglycoside or antipseudomonal FQ + vancomycin or linezolid

Question 27

Empiric therapy for sepsis in adults with hospital-acquired infection in non-neutropenic patients (ANC > 1000/mm3): UTI

Answer 27

1. cefepime + aminoglycoside (tobramycin) or FQ | 2. zosyn + aminoglycoside (tobramycin) or FQ

Question 28

Empiric therapy for sepsis in adults with hospital-acquired infection in non-neutropenic patients (ANC > 1000/mm3): suspected intra-abdominal source

Answer 28

1. zosyn | 2. carbapenem (not ertapenem)

Question 29

Empiric therapy for sepsis in adults with hospital-acquired infection in non-neutropenic patients (ANC > 1000/mm3): SSTI (cellulitis, necrotizing fasciitis)

Answer 29

vancomycin + zosyn (+ clindamycin if necrotizing fasciitis)

Question 30

empiric treatment of a hospital-acquired sepsis infection (neutropenic patient)

Answer 30

1. zosyn +/- aminoglycoside 2. antipseudomonal carbapenem (not erta) +/- aminoglycoside 3. ceftazidime or cefepome +/- aminoglycoside

Question 31

empiric treatment for sepsis infection with thermal injury to at least 20% of body SA

Answer 31

antipsuedomonal beta-lactam + aminoglycoside + vancomycin

Question 32

Empiric treatment for sepsis infection with suspicion of indwelling vascular catheter infection

Answer 32

vancomycin, daptomycin, linezolid

Question 33

duration of empiric therapy

Answer 33

7-10 days

Question 34

Vasopressors in sepsis/septic shock

Answer 34

1. target MAP of 65 mmHg 2. Norepinephrine is the first choice. 3. vasopressin can be added to NE to either increase MAP or decrease NE dose 4. Epinephrine may be added to NE and vaso if needed to maintain adequate blood pressure 5. dopamine alternative vasopressor only in highly selected patients (patients with low risk of tachyarrhythmias and bradycardia) 6. phenylephrine only in circumstances where NE is associated with serious arrhythmias, CO is known to be high and BP is persistently low, salvage therapy

Question 35

Inotropic therapy in sepsis/septic shock

Answer 35

dobutamine infusion may be administered or added to vasopressors in the presence of myocardial dysfunction or ongoing signs of hypoperfusion

Question 36

Corticosteroids in sepsis/septic shock

Answer 36

IV hydrocortisone for septic shock that remains poorly responsive to fluid resuscitation and vasopressors - do not administer in absence of shock