Bacteremia and Sepsis Flashcards
_____ is simply the presence of bacterial cells in the bloodstream
Bacteremia
Respiratory tract infections, especially pneumonia, are the leading cause (or entry point) of _____
sepsis
Describe how a bacterial infection in the lungs can spill over into the bloodstreem
- The distance between the blood and the air-filled alveoli is only 2 small epithelial cells thick
-If pneumonia occurs and the alveoli fill with bacterial colonies and pus, this 2-cell barrier could fail. - As the infection outside the bloodstream worsens, the epithelial layer is damaged and the bacterial cells can spill over into the bloodstream.
Three main areas where Bacteremia can occur
Respiratory tract
GI Tract
Genitourinary tract
How does Bacteremia occur in the Gastrointestinal Tract?
- The intestines are very vascular as large amounts of nutrients and fluid are absorbed from the gut.
- There is significant potential for quick entry into the blood for invading pathogens.
How does Bacteremia occur in the Genitourinary tract?
- When bacteria invades the urinary tract, we call this a UTI.
- If a UTI is allowed to proliferate, progression up to the kidneys can occur (pyelonephritis)
- The kidneys are highly vascular and the barrier between the urine and the blood is very thin, offering easy entry.
Other routes of entry for Bacteremia?
Dental abcesses
Cellulitis in an extremity
Mastoiditis
Strep Throat with a peritonsilar abcess
Infected surgical wound
Sinusitis
Bacterial presence in the blood can trigger the immune system with activation of _____
phagocytes
T/F Bacteremia will always cause sepsis
F
Bacterial presence in the blood can trigger the immune system with activation of phagocytes.
If the bacteria has a high degree of virulence, or if the patient is immunocompromised, the immune system may initiate a widespread, dysregulated response
The largest proportion of pathogens involved in sepsis are ____
Gram positive bacteria - 52.1%
T/F Sepsis is always caused by bacteria
F - viruses can cause it too!
Gram positive bacteria- 52.1%
Gram negative bacteria- 37.6%
Polymicrobial infection- 4.7%
Fungi- 4.6%
Viral- < 1% (although considered underdiagnosed)
SARS-CoV-2 was an important recent cause
Sepsis is responsible for about ___% of US hospital admissions
6
The most common bugs in Sepsis
- Staphylococcus aureus: Respiratory, ENT, Skin
- Streptococcus pneumoniae: Respiratory, ENT
- The Enterococci: Gastrointestinal, Urinary
- Klebsiella pneumoniae: Respiratory
- Pseudomonas aeruginosa: Pneumonia, Urinary, Vascular Access lines, Skin
- Escherichia coli: Urinary, Gastrointestinal
_____ is a dysregulated host response to infection that results in life-threatening organ dysfunction
Sepsis
Sepsis spectrum is _____
Infection, bacteremia, sepsis, septic shock, multiple organ dysfunction syndrome (MODS), death.
Definition of sepsis prior to 2016 (some clinics still use)
Systemic Inflammatory Response Syndrome (SIRS) due to a documented or suspected infection
SIRS (Systemic Inflammatory Response Syndrome) = 2 or more of the following abnormalities on physical exam and/or labs
Temp > 100.4 F (38 C) or < 96.8 F (36 C)
HR > 90 beats per minute
RR > 20 breaths per minute or partial pressure of CO2 (PaCO2) < 32 mmHg
White blood cell count (WBC) > 12,000 or < 4,000 cells/mm3
Why is the presence of SIRS is not currently the preferred diagnostic definition of sepsis for some experts?
If SIRS is used as the main criteria for diagnosing sepsis, some septic patients may be diagnosed later than ideal, during the shock stages.
- Diagnosed too late
In ____, the Society of Critical Care Medicine (SCCM), in collaboration with the European Society of Intensive Care Medicine, published new clinical guidelines for Sepsis
2016
T/F the SCCM definitions for Sepsis are unanimously accepted
F
The current SCCM’s definition of Sepsis, which was intended to replace the SIRS+infection definition
Sepsis is life-threatening organ dysfunction caused by dysregulated host response to an infection.
Organ dysfunction is defined as an ____
acute change in the total Sequential Organ Failure Assessment (SOFA) score by 2 or more points due to infection
SOFA
Sequential Organ Failure Assessment
SOFA looks at 6 organ systems to determine score:
Lungs/Respiration (using PaO2/FiO2 ratio)
Platelet Count
Liver Function (using Bilirubin level)
Cardiovascular/Blood Pressure
Brain Function (using Glasgow Coma Score)
Kidney Function (using Creatinine)
Two scoring systems sometimes used for early identification of those who may go on to develop severe sepsis
qSOFA and NEWS
qSOFA
“quick” SOFA is commonly used but is less specific than SOFA. Looks at 3 organ systems:
- Lungs/Respiration (respiration rate ≥ 22 per min)
- Cardiovascular/Blood Pressure (SBP </= 100 mmHg)
- Brain Function (altered mentation)
T/F qSOFA Is a part of the diagnostic definition of sepsis
F
Just for screening to identify high-risk patients
Examples of clinical evidence that suggest organ dysfunction or tissue hypoperfusion
Vascular: Sepsis-induced hypotension (low SBP or MAP)
Heart: Elevated troponin levels
Renal: Urine output < 0.5 mL/kg/hour for > 2 hours despite adequate fluid resuscitation, AND/OR Creatinine > 2 mg/dL
Liver: Elevated bilirubin
Hematologic: Platelet count <100,000 AND/OR elevated INR
Hypoperfusion: Elevated Lactic Acid (this is a big one)
Sepsis-induced hypotension definition
despite adequate fluid resuscitation, requires vasopressors to maintain a mean arterial pressure (MAP) ≥ 65 mmHg AND have a lactate > 2 mmol/L.
Septic shock is associated with a greater risk of ____ than sepsis alone (≥ 40% risk vs ≥ 10% risk)
mortality
Diagnostic Studies with Sepsis
CBC with diff
CMP (electrolytes, glucose, LFTs, albumin, bilirubin)
Serum lactate
Arterial blood gases (ABGs) - particularly if hypotensive
Amylase and Lipase
Urinalysis
Blood cultures (2 sets) - as long as does not delay Abx by 45 min
Consider cultures from easily accessible sites (sputum, urine, etc.)
Diagnostic Imaging Studies with sepsis
Chest X-ray - Common, particularly if respiratory suspect.
Abdominal CT if abdominal infection is suspected.
CT Head if focal neurologic deficit on exam.
Echocardiogram if murmurs or suspected endocarditis.
Other applicable imaging (such as US of soft tissues)
*Always consider your patient’s stability/risk for transport to imaging or invasive procedures
A true concern we have in sepsis is the fact that there’s no ___
perfect gold standard test
Diagnosing sepsis requires ____
quick critical thinking and clinical reasoning.
-We are often initiating treatment based on a suspected diagnosis, deciding this empirically at the bedside upon patient presentation
____ are sets of interventions or care processes based on clinical guidelines, that when implemented correctly, contribute positively to quality care
Bundles
The following clinical actions should occur between the initial recognition of severe sepsis or septic shock and the 3-hour mark, the SEP-1 bundle:
Serum lactate measurement.
Blood/other culture prior to antibiotics.
Antibiotic therapy initiated (targeted or broad spectrum).
Initial IV fluid therapy of 30 mL/kg of crystalloid (if SBP < 90, MAP < 65, or serum lactate > 4 mmol/L).
If initial lactate is > 2, repeat lactate is required prior to 6 hours from initial recognition
Hour-1 Bundle Recommends the same actions as SEP-1 occur w/in 1 hour with the strongest evidence supporting:
initiation of the antibiotic within the first hour
After SEP-1 or Hour-1 is initiated, what is done necxt?
- Secure airway and give O2 (if indicated).
- Lactate and blood cultures should be obtained.
- Initiate fluid resuscitation with crystalloid IV fluids
- Initiate broad-spectrum antibiotics ASAP
- Plan for source control if applicable
Which Antibiotic to start with sepsis, with and without shock? What about with MRSA?
Sepsis without shock: 1 broad-spectrum Abx.
- Ex: Meropenem (Merrem) or Piperacillin-Tazobactam (Zosyn).
With septic shock: combination therapy is advised
- Ex: Meropenem or Zosyn, PLUS Vancomycin.
Anytime MRSA is a concern, add Vanco
Sepsis with a source of CAP often require what antibiotics
Levo or moxifloxacin are often added
T/F If the source of sepsis is thought to be fungal, particularly in a patient with neutropenia, antifungal treatment should accompany antibiotic treatment.
T
Monitoring for Sepsis during treatment
Monitor response to initial IV fluid resuscitation
If refractory hypotension, initiate vasopressor
Consider RBC transfusion if hemoglobin < 7.
Approximately ___ millions cases of sepsis occur globally each year
48-50
Approximately ____ million deaths are attributed to sepsis each year
11
The incidence of sepsis seems to vary among racial and ethnic groups, but appears to be highest among ____
black and Hispanic populations
Prognosis in Septic patients:
“Severe Sepsis” (sepsis with severe organ dysfunction): Mortality of 25-40%!
Septic Shock (sepsis with refractory hypotension)
Mortality of 40-80%!
Risk of sepsis increases exponentially after the age of ____.
60
Common causes of Nosocomial Sepsis
Ventilator pneumonia
Surgical site infection
Bladder catheter infection
Vascular catheter infection
