Sepsis Flashcards
Systemic Inflammatory Response Syndrome (SIRS)
AKA Cytokine storm
Release of large quantities of cytokines in response to stimulus
Cytokines are chemical mediators of inflammation and immune response
Causes multiple organ dysfunction
SIRS Criteria
At least 2 of 4: 1. Fever (>38 C, 100.4F) or hypothermia (<36 C, 96.8F) 2. Tachycardia (>90 bpm) 3. Tachypnea (>24 breaths/minute) 4. Leukocytosis (>12,000cells/mm3) Leukopenia (<4000 cells/mm3) OR Left shift (>10% immature band cells) AKA elevated or lower WBC count
A diffuse fungal infection could make a patient hypothermic and leukopenic
Many things could cause a patient to have SIRS, so this definition is not used as much anymore
Sepsis
At least 2 of 4 SIRS criteria
PLUS
Suspected or proven infection
Severe sepsis
At least 2 of 4 SIRS criteria
PLUS
suspected or proven infection
PLUS
end-organ dysfunction in one or more organ systems
(CV, renal, resp, hema, metabolic acidosis)
Sig. decreased urine output Changes in mental status Decreased platelets Difficulty breathing Abnormal heart function Abdominal pain
Septic shock
At least 2 of 4 SIRS criteria
PLUS
suspected or proven infection
PLUS
end-organ dysfunction in one or more organ systems
(CV, renal, resp, hema, metabolic acidosis)
PLUS
Hypotension (systolic bp <90mmHg or >40 mmHg decrease from baseline) despite adequate fluid resuscitation, requiring pressor therapy
Refractory septic shock
At least 2 of 4 SIRS criteria
PLUS
suspected or proven infection
PLUS
end-organ dysfunction in one or more organ systems
(CV, renal, resp, hema, metabolic acidosis)
PLUS
Hypotension (systolic bp <90mmHg or >40 mmHg decrease from baseline) despite adequate fluid resuscitation, requiring pressor therapy
AND THEN
It lasts for 1 hour despite fluid resuscitation and pressor therapy
May lead to death
New classification of Sepsis syndromes
Since 2016 Society of Critical Care Medicine
Early sepsis > Sepsis > Septic shock
Leads to multiple organ dysfunction syndrome (MODS) and death
Early Sepsis and qSOFA
Assuming they already have an infection
Quick Sequential (sepsis-related) Organ Failure Assessment score (qSOFA)
qSOFA score <2: 3% risk of mortality
qSOFA score >=2: 18-24% risk of mortality
Resp rate >=22
Altered mentation
Systolic blood pressure <=100mmHg
Sepsis
Life-threatening organ dysfunction caused by infection with dysregulated host response
When your body’s inflammatory response to infection gets out of hand
SOFA score:
Increase of 2+ points
Not diagnostic of sepsis or infection (need other things to tell us if patient is actually sick with infection)
Assess for end-organ dysfunction
Identify patients who are at risk of death
Septic Shock
Vasodilation or distribution problem due to sepsis causing circulatory, cellular, or metabolic derangements
Sepsis (assuming patient has an infection)
Requirement of vasopressors to maintain mean arterial pressure (MAP) of >65 mmHg
Keep BP up, profusion, organs get the blood they need
Lactate >2mmol/L
> 40% mortality vs >10% with sepsis alone
28 day mortality is 40-70%
Shock
- Diminished cardiac output or reduced effective circulating blood volume
- Impairs tissue perfusion and leads to cellular hypoxia
- Can lead to cell death and eventually organ failure and death if not corrected immediately
Can be reversible or fatal
Caused by many things (not just infection):
- Infection (inflammatory cytokines)
- Anaphylaxis (severe allergic reaction- vasodilator response, pass out, die)
- Cardiac abnormality (if your heart can’t pump regularly)
- Hypovolemia (bleeding out, losing blood for organs)
Multiple Organ Dysfunction Syndrome (MODS)
Progressive
Primary (result of defined insult) or secondary (result of indirect insult to due host response)
No universally accepted criteria (use SOFA score)
Sepsis stats
> 750,000 cases of severe sepsis or septic shock a year
As many as AMIs
Most common cause of death in ICU (non-cardiac)
3rd leading cause of death in US
Frequency increasing:
- More aggressive surgery
- More resistant organisms (infections have become resistant to antibiotics)
- More immune compromise from diseases and meds (cancer)
- Increased elderly living with chronic diseases (AIDS, because we can treat it)
- Widespread use of catheters/mechanical devices (foreign bodies in people, increasing risk of infection)
What constitutes poor prognosis with septic shock?
Increased age Comorbid medical conditions High APACHE II score Elevated lactate Insufficient response to vasopressors Delay in treatment
Infectious causes of sepsis
- Opportunistic infections (wouldn’t normally cause infections in immunocompetent hosts)
- Host factors (comorbid disease like COPD, diabetes, hypertension)
- Indwelling lines/catheters/foreign bodies (obstruction of normal drainage)
- Microbial factors (evading immune system and antibiotics we use to treat; toxins we cannot treat)
- Microbes (gram+,gram-, fungi, virus)
- Infections
Pneumonia
Lung infection
Peritonitis
Infection in abdominal cavity (with liver disease)
Pyelonephritis
Kidney infection
Abscess
Especially intra-abdominal
If you have surgery and they nick the bowel and the contents leak out into the belly, that could form an abscess
Cholangitis
Infection in gall bladder
Cellulitis and necrotizing fasciitis
Skin, fascia, muscle, bone; think all layers
Cardiogenic shock
Caused by:
- Myocardial infarction (patient is hypotensive because heart muscle can no longer pump)
- Ventricular rupture (from trauma)
- Arrhythmia (rhythm not compatible with life)
- Cardiac tamponade (Heart leaks out into space between heart muscle and pericardium, fluid presses on heart and prohibits it from pumping blood)
- Pulmonary embolism
Mechanism:
Failure of myocardial pump resulting from intrinsic myocardial damage, extrinsic compression, or obstruction to outflow
Hypovolemic shock
Caused by: Fluid loss (hemorrhage, vomiting, diarrhea, burns, trauma)
Mechanism:
Inadequate blood or plasma volume
Systemic inflammation
Caused by:
- Overwhelming microbial infections (bacterial and fungi)
- Superantigens (toxic shock)
- Trauma, burns, pancreatitis
Mechanism:
- Cytokine cascade activation
- Vasodilation and pooling of blood and intravascular coagulation
- Endothelial activation/injury (immune system inflammatory response that is causing the shock)
- Leukocyte-induced damage
- DIC