Sepsis/inflammation Flashcards
What are the criteria to diagnose septic shock?
-requires a vasopressor to maintain MAP > 65mmHg
-serum lactate >2 in the absence of hypovolemia
What is the mortality associated w/ septic shock?
40% or greater
Which Candida species is intrinsically resistant to azoles (fluconazole)?
Candida glabrata
The major cause of vasodilation in sepsis is likely mediated by what?
ATP-sensitive K channels in smooth muscle
-increases permability of vasc smooth muscle cells to K
-hyperpolariaztion of cell membranes preventing muscle contraction
For pts in vasodilatory shock on high-dose pressors and steroids what agent can be added to improve arterial pressure?
Angiotensin 2
-typically see a 45% absolute increase in MAP response when compared to placebo
What effect on the vascular system does angiotensin 2 have?
potent vasoconstrictor
In what patient population is angiotensin 2 contraindicated?
those on ACE inhibitors
What are the two most common causes of bacterial meningitis in ages 16-50?
-Streptococcus pneumoniae
-Neisseria meningitidis
What is most likely to normalize first for pts after an ICU discharge?
pulmonary function
What is a type 1 NSTI?
polymicrobial w/ GP and GN organisms
-on average have 4 isolates of aerobes and anaerobes
-most common isolates: streptococci, staphylococci, enterococci, E. coli, Klebsiella Pseudomonas, Acinetobacter, Bacteroides, Clostridial species
What is a type 2 NSTI?
monomicrobial, usually GAS (Streptococcus pyogenes) or MRSA
-accounts for 15% or less of NSTIs
What is a type 3 NSTI?
monomicrobial, most commonly Clostridium, but can be Aeromonas hydrophila or Vibrio vulnificus
-can be any Clostridium species, but usually C. perfringens
-a/w IVD and surgical wounds
What is the most common type of NSTI?
type 1 (polymicrobial) making up 50-75% of all infections
What are some risk factors for type 1 NSTI?
-DM
-PVD
-obesity
-chronic renal failure
-EtOH abuse
What type of NSTI is Fournier gangrene and Ludwig angina typically?
type 1
What is the most common cause of DIC? And other causes?
-sepsis
-trauma, malignancy, aortic aneurysms, OB complications
What type of sepsis is DIC classically associated with?
gram-negative sepsis
What test is used to check for cryptococcal meningitis?
CSF India ink stain
What supplementation can help reduce rates of systemci bacteremia in critically ill patients?
-glutamine
-L arginine
-these can reduce systemic bacteremia, immune maintenance, and gut flora preservation
What is the “dangerous area” of the face and what are its borders?
-area where venous drainage goes directly into cavernous sinus so any infection can lead to cavernous sinus thrombosis
-triangular area from corners of the mouth to the nasal bridge, to include the lower part of the nose and maxilla
Gram-negative, encapsulated, non-motile bacterium describes which organism?
Klebsiella pneumoniae
What culture result is suggestive of MRSA?
GPC that is mecA positive
What is the mortality rate of CLABSI?
12-25%
-2nd most preventable healthcare acquired infection
-8th leading cause of death in US
Bacteruria is present in what percent of patients after having a catheter for 2 days?
25%
What are risk factors for CAUTI?
-female
-chronic catheter use
-chronic health conditions
-at risk populations (elderly, immunocompromised)
-improperly placed foleys w/ break in sterile technique
What differentiates CA-ASB from CAUTI?
-CA-ASB = catheter associated asymptomatic bacteruria
-pt is asymptomatic w/ >/= 10^5 CFU on culture
-CAUTI = catheter associated UTI
-pt is symptomatic w/ >/= 10^3 CFU
What is the treatment for CAUTI?
-GN infection that is otherwise uncomplicated ceftriaxone 1gm daily or cefotaxime 1gm q8hr for 7-14 days
-if not in the ICU can consider levofloxacin x5 days
Which pts are at risk for candida CAUTIs?
-chronic catheters
-anatomic abnormalities
-diabetes
-chronic abx use
What is the mortality rate for VAP?
15-25%
What are the risk factors for VAP?
-chronic disease
-lung disease
-age
-aspiration
-supine
-paralytic use
What are risk factors for VAP that are specific to trauma?
-increased ISS
-decreased GCS
-blunt mechanism of injury
-emergent intubation
-shock
-advanced age
-increased transfusion requirements
-injury pattern
What is the incidence of PNA in pts w/ GCS 3-8?
40%
What is the rate of sepsis in hospitalized patients? In ICU pts?
-1-11%
-30%
What is the rate of septic shock in ICU pts?
15%
What is the mortality of septic shock in ICU pts?
30-50%
What is the Sepsis 3 definition of sepsis?
-life-threatening organ dysfunction d/t dysregulated host response to infection
-organ dysfunction = SOFA score increase of 2 or more
What is the Sepsis 3 definition of septic shock?
sepsis with:
-hypotension that persists despite adequate fluid resuscitation and requires vasopressors to keep MAP > 65
-lactate >/= 2
Which inflammatory mediators are released by the innate immune system in response to sepsis?
-TNF-alpha
-IL 6
-IL 10
-TGF-beta
What characterizes the immune system of a septic pt?
-persistent impairment of neutrophil function
-increased lymphocyte and dendritic cell apoptosis
-shift from Th1 to Th2 cytokine profile
-increase in T regulatory cells
-release of anti-inflammatory mediators
-monocyte deactivation
-immature myeloid-derived suppressor cells
In what percent of pts is no source of sepsis identified?
30-40%
What components make up the SOFA score (sequential organ failure assessment)?
-PaO2/FiO2
-PLT count
-bilirubin
-MAP or pressor requirement
-GCS
-creatinine
-UOP
What is the recommendation for fluid resuscitation in septic shock?
30mL/kg of IV crystalloid given in 3 hours or less
What factors are associated w/ NSTI?
-immunocompromised
-DM
-COPD
-coronary heart disease
-chronic renal insufficiency
-history of traumatic injury or surgery
-IV drug use
What percent of pts w/ NSTI had no predisposing factors?
~20%
How does the indirect necrosis d/t the toxins release in NSTIs occur?
-perforating vessel thrombosis
-vasoconstriction that worsens tissue hypoxia
What are the common aerobic pathogens of NSTIs?
-Streptococcus
-Enterococcus
-Staphylococcus
-Escherichia coli
-Klebsiella
-Proteus
What are the common anaerobic pathogens of NSTIs?
-Clostridium
-Bacteroides
-Peptostreptococcus
What is a type 1 NSTI?
polymicrobial
-includes GPC, GNR, and anaerobes (Clostridium)
-pts are typically older w/ comorbidities
-if leads to shock then mortality is > 50%
What is a type 2 NSTI?
involve a group A beta-hemolytic streptococci
-can be isolated or w/ Staphylococcus
-more related to IVDU so can be a younger population
What is a type 3 NSTI?
caused by GN marine organisms
-most common is Vibrio vulnificus
What percent of NSTIs are polymicrobial?
> 75%
On average how many organisms are in a polymicrobial NSTI?
4
What are the local early signs of NSTI?
-erythema
-warmth
-tenderness
-myalgia
-hypersensitivity
What are the late local signs of NSTI?
-hematic/gas bullae
-necrosis
-purple/blue skin
-crepitus
-cutaneous anesthesia
-sensory/motor loss
What are the systemic early signs of NSTI?
-pain out of proportion
-swelling
-fever
What are the systemic late signs of NSTI?
-hypotension
-confusion
-MOF
What labs are suggestive of an NSTI?
-WBC > 15.4, esp. w/ bandemia
-Na < 135
-BUN > 15
-CRP > 149
-decreased bicarb
-elevated lactate
What is the increase in NSTI mortality if care is delayed for > 24hrs?
32% to 70%
What antibiotics can be used in pts w/ NSTIs and PCN allergies?
fluoroquinolones w/ additional GN and anaerobic coverage or carbapenems
How does cardiac output change (in broad terms) throughout septic shock?
-increases as a normal adaptive stress response
-peaks and plateaus during early decompensation
-drops off during clinical septic shock when SVR < 800
How does systemic vascular resistance change (in broad terms) throughout septic shock?
-decreases as a normal adaptive stress response
-nadir and plateaus during early decompensation, or just after
-rises relatively quickly during clinical septic shock when SVR < 800
What is the definition of a superficial surgical site infection?
-involves only skin or subQ tissue
-occurs w/in 30 days of an operation
-has at least 1 of:
-purulent drainage
-localized signs of infection that require opening of superficial wound
-positive wound culture
What is the definition of a deep surgical site infection?
-involves the fascia and muscle layers
-occurs w/in 30 days of operation
-has at least 1 of:
-purulent drainage from deep incision
-fever of 38C or greater, localized pain, or spontaneous dehiscence
-abscess in the deep wound
What is the definition of an organ space surgical site infection?
-involves the any part of the anatomy that is not the incision which was manipulated during the surgery
-has at least one of:
-purulent drainage from a drain that is placed
-positive cultures from the space
-abscess in the organ or space
What is the risk of infection in a class 1 surgical wound?
1.5%
What is the risk of infection in a class 2 surgical wound?
15%
What is the risk of infection in a class 3 surgical wound?
15%
What is the risk of infection in a class 4 surgical wound?
40%
Which GPC do you need to consider for nosocomial infections?
-S. aureus (wound infections)
-S. epidermidis (catheters, shunts, prosthetics)
-S. pyogenes (GA beta-hemolytic; post-op wound infections)
-E. faecalis (peritoneal and pelvic infections)
Which GP bacilli do you need to consider for nosocomial infections?
-clostridium
-actinomyces
-nocardia
Which GN bacilli do you need to consider for nosocomial infections?
-E. coli
-klebsiella
-proteus
-enterbacter
-serratia
-pseudomonas
Which anaerobic do you need to consider for nosocomial infections?
-B fragilis
-clostridium
In surgical pts what are the most common bacteria found in surgical wound infections?
-S. aureus
-Enterococci
-E. coli
In surgical pts what are the most common bacteria found in bacteremia?
-coag neg staph
-S. aureus
-enterobacter
In surgical pts what are the most common bacteria found in UTIs?
-E. coli
-pseudomonas
-enterobacter
In surgical pts what are the most common bacteria found in respiratory infections?
-pseudomonas
-S. aureus
-enterobacter
In surgical pts what are the most common bacteria found in cutaneous infections?
-S. aureus
-pseudomonas
-enterococci
What is the SBP mortality rate?
25%
What is the most common bacteria found in immunocompromised pts?
pseudomonas
What is the definition of sepsis using MEWS (modified early warning score)?
-MEWS >/= 5 + infection
-medium risk if 2 - 4
What are the categories looked at in MEWS?
-SBP
-HR
-RR
-temp
-AVPU (alert/reacts to voice/reacts to pain/unresponsive)
