Sepsis Recap Flashcards
Define SIRS
Systemic inflammatory response syndrome.
Widespread inflammatory response to an infectious or non-infectious insult
Define sepsis (old def)
SIRS + documented or suspected infection
Define sepsis (new def)
life-threatening organ dysfunction caused by a dysregulated host response to infection.
Organ dysfunction is defined as SOFA (or q SOFA) score >/= 2
Define severe sepsis (old def)
Sepsis + evidence of organ dysfunction
Define severe sepsis (new def)
No such thing! All sepsis is “severe” now.
Define septic shock (old def)
Sepsis + hypotension that is not responsive to fluid therapy
Define septic shock (new def)
- a subset of sepsis in which particularly profound circulatory, cellular, and metabolic abnormalities are associated with a greater risk of mortality than with sepsis alone.
Vasopressors required to maintain MAP >65
AND
Lactate >2 in the absence of hypovolemia
Define MODS
multiple organ dysfunction syndrome.
Sepsis/SIRS + more than one organ dysfunction.
Increase in SOFA score of >/= 2 points.
What are the components of a SOFA score?
- Respiration: based on PaO2/FiO2 ratio
- Coagulation: based on platelet count
- Liver: based on bilirubin
- Cardiovascular: based on MAP
- CNS: based on Glasgow coma scale
- Renal: based on creatinine and urine output
What are the components of a qSOFA score?
3 categories not requiring lab work, score 0 or 1
RR >22/min
Altered mentation
Systolic BP <100mmHg
List 8 other findings of organ dysfunction with sepsis/SIRS that are not accounted for with a SOFA score.
- Hyperglycemia
- Hypoglycemia
- GI signs (V/D)
- Cardiac dysfunction (arrhythmias, impaired contractility)
- Immune dysregulation (CARS)
- Mitochondrial dysfunction
- Vascular leak/increased vascular permeability
- Hypoalbuminemia
What are the 4 basic steps in sepsis treatment?
- Identification
- Administer broad spectrum antibiotics (within 1 hr of ID)
- Systemic Stabilization
- Source Control
List the 5 major catecholamine receptors.
α1
α2
β1
β2:
dopaminergic (D receptors)
What are the effects of stimulation of alpha 1 (α1) receptors?
vasoconstriction (arterial and venous)
mild positive inotrope
What are the effects of stimulation of alpha 2 (α2) receptors?
primarily vasoconstriction, but vasodilation of vital organs
What are the effects of stimulation of beta 1 (β1) receptors?
Positive inotrope and chronotrope
What are the effects of stimulation of beta 2 (β2) receptors?
Vasodilation of vital organs
Bronchodilation
What are the effects of stimulation of Dopaminergic (D) receptors?
vasodilation of smooth muscle (renal, splanchnic, coronary, cerebrovascular).
What are the primary receptors stimulated by norepinephrine?
Primarily α
mild β (increases SVR)
What are the primary receptors stimulated by epinephrine?
Non selective α and β
What are the primary receptors stimulated by Dopamine?
Low dose (1-5mcg/kg/min): dopaminergic receptors
Mid dose (5-10): primarily β1, some α (positive inotrope/chronotrope with mild increase in SVR)
High dose (10-20): primarily α1 (vasoconstriction), lower GI blood flow
What are the primary receptors stimulated by dobutamine?
Beta only (β 1 > β 2)
What are the primary receptors stimulated by vasopressin?
V1: vasoconstriction
V2: found in the renal collecting duct, increases water reabsorption (increases aquaporin channels in the duct)
V3: stimulate release of ACTH from the pituitary
According to the Surviving Sepsis Guidelines, what is the preferred vasopressor for septic shock?
List the other options in order of preference.
- Norepinephrine
- Epinephrine
- Vasopressin
- Dopamine
- Phenylephrine- not really recommended at all anymore
Which of these are indications for administering steroids to a septic patient?
- Low random cortisol level
- Decreased “delta” cortisol on an ACTH stimulation test
- Hypotension that is poorly responsive to fluid and vasopressor therapy
- Fever
- Early severe ARDS (PaO2/FiO2 <200)
- Hypotension that is poorly responsive to fluid and vasopressor therapy
- Early severe ARDS (PaO2/FiO2 <200)
What are 6 other measures that can be considered in a septic patient with hypotension poorly responsive to fluid therapy, vasopressors, and hydrocortisone?
- Positive inotropes (dobutamine, pimobendan?)
- Blood transfusion if indicated (higher transfusion threshold)
- Mechanical ventilation
- Colloid therapy if hypoalbuminemic or requiring high dose crystalloids
- Bicarbonate therapy if severely acidotic (pH < 7.1)
- Calcium supplementation if severely hypocalcemic
Amoxicillin:
MOA:
Cidal or static:
Spectrum:
MOA:
B-lactam.
Inhibit cell wall synthesis by binding to and inhibiting penicillin binding proteins (which catalyze cross linking of glycopeptides that form the cell wall).
Cidal or static: Cidal
Spectrum: G (+), G (-), anaerobes
Cefotaxime:
MOA:
Cidal or static:
Spectrum:
MOA:
B-lactam (3rd gen cephalosporin).
Inhibit cell wall synthesis.
Cidal or static: Cidal
Spectrum: G (-)
Metronidazole:
MOA:
Cidal or static:
Spectrum:
MOA: Inhibit RNA and DNA synthesis
Cidal or static: Cidal
Spectrum: Anaerobes
Enrofloxacin:
MOA:
Cidal or static:
Spectrum:
MOA: Inhibit DNA gyrase
Cidal or static: Cidal
Spectrum: G(-)
Azithromycin:
MOA:
Cidal or static:
Spectrum:
MOA: Inhibit protein synthesis via the 50S subunit
Cidal or static: Static
Spectrum: G (+), mycoplasma
Chloramphenicol:
MOA:
Cidal or static:
Spectrum:
MOA: Inhibit protein synthesis via the 50S subunit
Cidal or static: Static
Spectrum: G (+), G (-), anaerobes
Clindamycin:
MOA:
Cidal or static:
Spectrum:
MOA: Inhibit protein synthesis via the 50S subunit
Cidal or static: Static (except at high doses)
Spectrum: G (+), anaerobes
Tetracycline:
MOA:
Cidal or static:
Spectrum:
MOA: Inhibit protein synthesis via the 30S subunit
Cidal or static: Static
Spectrum: G (+), G (-), anaerobes
Amikacin:
MOA:
Cidal or static:
Spectrum:
MOA: Inhibit protein synthesis via the 30S and 50S subunits
Cidal or static: Cidal
Spectrum: G (-), staph
Suflas:
MOA:
Cidal or static:
Spectrum:
MOA: Inhibit folic acid synthesis 🡪 impaired protein and nucleic acid metabolism
Cidal or static: Static
Spectrum: G (+), G (-), anaerobes
Define cMax:
peak concentration of a drug after administration
Define MIC
lowest concentration of an antibiotic with no evidence of bacterial growth.
Define Breakpoint
The approximate concentration of the drug that can be achieved safely in the plasma given the clinically accepted dose and route (takes into account pharmacology of the drug)
How can you use the breakpoint and MIC to choose the best antibiotic for your patient?
Subtract Breakpoint from MIC- choose drug with largest number.
Use higher doses (if safe) if you absolutely have to use drugs with breakpoint near the MIC.
Explain time dependent antibiotics.
Time dependent antibiotics are those where the amount time spent above MIC is the major determinant of effectiveness (generally given multiple times daily).
Try to keep the concentration at 2-4 x MIC over dosing interval.
Explain concentration dependent antibiotics.
Concentration dependent antibiotics are those where the height of cMax is the major determinant of effectiveness (generally given once daily).
cMax should be at least 10-12 x the MIC to be effective.
Concentration dependent antibiotics often have a “post antibiotic effect” in which killing continues after the antibiotic concentration has dropped below MIC.
Examples of time dependent antibiotics.
B-lactams
vancomycin
clindamycin
macrolides