Topic 30: Sepsis
- Definition
Sepsis is a life-threatening organ dysfunction caused by a dysregulated host response to infection.
Sepsis is caused by an immune response to infection (commonly bacterial, but can be fungal, viral or parasitic). The primary infection can be found in any of the bodies organs (especially lungs, brain, urinary tract, skin and abdominal organs). There is increased risk in those in immunocompromised state
- Basic Terminology
Infection = invasion and multiplication of microorganisms in normally sterile tissue.
Inflammation = stereotyped local immune response to infection or injury.
Surgical Infection = may or may not lead to systemic effects.
Note: Sepsis ≠ SIRS (Systemic Inflammatory Response Syndrome), but SIRS can progress into sepsis.
- Spectrum of Sepsis
- SIRS – Criteria (≥2 of the following):
Temperature: >38°C or <36°C
Heart rate: >90 bpm
Respiratory rate: >20/min or PaCO₂ < 4.3 kPa
WBC: >12,000 or <4,000 / μL
- Etiology & Risk Factors
High- risk groups:
Elderly or neonates
Immunocompromised (AIDS, leukemia, lymphoma)
Diabetes mellitus
Patients with indwelling devices (catheters, stents)
Postoperative/invasive procedures
Long- term antibiotic therapy
Common sources of infection:
Genitourinary system
Gastrointestinal tract
Respiratory tract
Skin/wound infections
- Pathophysiology
Infection triggers massive cytokine release (IL- 1, TNF- α, IL- 6)
Leads to:
- Endothelial damage
- Capillary leak
- Tissue hypoperfusion
- Mitochondrial dysfunction
Results in:
- Lactic acidosis
- Multiple organ failure
- Circulatory collapse (septic shock)
- Clinical Features
General:
- Fever or hypothermia
- Tachycardia
- Tachypnea
- Chills
- Sweating
- Altered mental status
- Hypotension (if severe)
Local signs (may be minimal):
- Reduced or absent wound secretion
- Pale or necrotic granulation
- Poor response to antibiotics
Progression:
- Organ dysfunction signs:
↓ urine output
Dyspnea or hypoxia
Jaundice
Coagulopathy
Confusion/coma
- Laboratory Investigations
- Imaging (in septicopyemia )
X-ray / CT scan: May show metastatic pyogenic foci (lung, liver, brain, bone)
Ultrasound: Source localization
Echo: For suspected infective endocarditis
- Complications
Septic shock
Acute respiratory distress syndrome (ARDS)
Disseminated intravascular coagulation (DIC)
Multiple Organ Dysfunction Syndrome (MODS)
- Prognosis (Mortality)
- Treatment
- Initial Management (within 1st hour = Sepsis Bundle)
- Oxygen: Maintain saturation >94%
- IV Access + Fluids: 30 mL/kg crystalloids (e.g. Ringer lactate) within 3 hours
- Blood cultures: Before antibiotics
- Empirical antibiotics: Broad- spectrum (e.g., ceftriaxone + metronidazole)
- Monitor lactate: Reassess after 2–4 hours
- Vasopressors: If MAP < 65 mmHg (norepinephrine is 1st line)
- Supportive Measures:
Ventilation if ARDS
Renal support (dialysis)
Glycemic contro
Nutrition support
Remove source (e.g. abscess drainage, catheter removal)