A.40 Bacteremia and Septicemia Flashcards
A.40 Bacteremia and Septicemia
Bacteremia:
Bacteremia
Bacteremia refers to the presence of bacteria in the bloodstream.
- It can occur from common activities (e.g., vigorous tooth brushing), dental or medical procedures, or infections.
- Often, bacteremia does not show symptoms, but it can lead to infections and serious complications.
Individuals who are unable to clear bacteria through their immune system may accumulate them in various body parts, potentially leading to conditions such as Meningitis, Pericarditis, Endocarditis, Osteomyelitis, and other infections.
A.40 Bacteremia and Septicemia
Symptoms:
Bacteremia
Clinical features depend on the suspected source for bacteremia; affected individuals can also be asymptomatic and bacteremia can resolve spontaneously.
Systemic signs:
Fever (most common)
Chills and rigors
A.40 Bacteremia and Septicemia
Diagnosis:
Bacteremia
Involves culturing a blood sample (either through venipuncture or using an indwelling catheter).
A.40 Bacteremia and Septicemia
Prevention
Bacteremia
Prophylactic antibiotic treatment is recommended for high-risk patients.
A.40 Bacteremia and Septicemia
Treatment:
Bacteremia
Antibiotics.
A.40 Bacteremia and Septicemia
Septicemia:
Septicemia
Sepsis is a severe, life-threatening condition caused by organ dysfunction due to an inappropriate response to infection.
A.40 Bacteremia and Septicemia
Etiology:
Septicemia
Common primary infections include:
Respiratory, gastrointestinal, genitourinary, skin, and soft tissue infections.
Pathogens:
Bacterial: Gram-positive and gram-negative bacteria.
Fungal, viral, or parasitic infections.
A.40 Bacteremia and Septicemia
Risk Factors:
Septicemia
Age: Individuals under 1 year or over 75 years.
Underlying conditions: Chronic illnesses (e.g., diabetes, cirrhosis), acquired pneumonia, bacteremia, and alcohol abuse.
Immune suppression: Conditions such as neutropenia or corticosteroid treatment.
Intensive care or prolonged hospitalization (nosocomial infections).
A.40 Bacteremia and Septicemia
Pathophysiology:
Septicemia
Sepsis represents a state of a hyper-inflammatory systemic reaction.
1. Activation of Inflammatory Mediators
Triggers from the immune system, such as the complement system, mast cells, and macrophages, cause a release of pro-inflammatory cytokines (e.g., TNFα, IL-1).
2. Endothelial Disruption
Leads to changes in capillary permeability, allowing fluid to leak into tissues.
3. Intravascular Coagulation
Activation of the coagulation cascade leads to disseminated intravascular coagulation (DIC) and microvascular thrombosis.
4. Tissue Ischemia
Results from decreased oxygen delivery, leading to cellular injury.
A.40 Bacteremia and Septicemia
Clinical Features:
Septicemia
Initial Presentation: Patients often present with poor overall condition and generalized edema.
Common Symptoms:
Fever, chills, and diaphoresis.
Tachycardia: Increased heart rate.
Tachypnea: Rapid breathing.
Organ Dysfunction Indicators:
Cardiovascular System: Alterations in mean arterial pressure (MAP).
Coagulation: Coagulopathy (abnormal blood clotting).
Hepatic Function: Elevated liver enzymes and bilirubin.
Renal Function: Increased creatinine levels.
Pulmonary System: Symptoms of acute respiratory distress syndrome (ARDS).
A.40 Bacteremia and Septicemia
Additional Features in Septic Shock
Septicemia
Severe Hypotension (systolic blood pressure < 65 mmHg).
Initially warm skin with normal capillary refill time may progress to cold, cyanotic skin as shock worsens.
Focus on addressing the primary infection.
A.40 Bacteremia and Septicemia
Diagnostics:
Septicemia
Identify the Responsible Pathogen:
- Conduct Gram stain and cultures of blood and urine.
- Based on symptoms, evaluate other body fluids (e.g., sputum, especially if cough is present; or stool, if diarrhea is evident).
Determine the Site of Primary Infection:
- Use imaging studies.
- Consider lumbar puncture if central nervous system (CNS) involvement is suspected.
- Perform echocardiography if necessary.
Assess Organ Dysfunction:
- Look for coagulation abnormalities:
- Tests: PT, aPTT, INR, TIBC, ALT, AST, and liver enzymes.
- Monitor renal function:
- Check blood urea nitrogen (BUN) and creatinine levels.
A.40 Bacteremia and Septicemia
Treatment:
Septicemia
Immediate Resuscitation (Respiratory and Circulatory Support):
Begin resuscitation promptly if there are indicators of respiratory failure, severe hypotension, or peripheral perfusion issues.
Empiric Antibiotic Therapy:
Initiate treatment for suspected MRSA infection using:
Vancomycin or linezolid or daptomycin.
If a Pseudomonas infection is suspected, consider adding:
Piperacillin/tazobactam.
A.40 Bacteremia and Septicemia
Complications:
Septicemia
Be aware of critical illness polyneuropathy, which may cause motor neuron impairment or muscular atrophy, leading to bilateral, symmetrical, flaccid paralysis that could affect diaphragm function.
