Sepsis

Definition
Sepsis is a life-threatening organ dysfunction caused by a dysregulated host response to infection. It represents a medical emergency requiring rapid recognition and treatment to prevent septic shock and death.

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Causes

• Bacterial infections (most common): Escherichia coli, Staphylococcus aureus, Streptococcus pneumoniae

• Viral infections: Influenza, SARS-CoV-2

• Fungal infections: Candida species

• Common infection sources: pneumonia, urinary tract infection, intra-abdominal infection, skin/soft tissue infection, indwelling devices

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Risk Factors

• Age <1 year or >65 years

• Immunosuppression (HIV, chemotherapy, steroids)

• Chronic diseases (diabetes, chronic kidney disease, liver disease, heart failure)

• Recent surgery or hospitalisation

• Invasive devices (catheters, ventilators)

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Pathophysiology

• Infection triggers widespread release of inflammatory mediators

• Endothelial dysfunction → increased vascular permeability → hypotension

• Coagulation abnormalities → microthrombosis → impaired tissue perfusion

• Leads to organ dysfunction (e.g., lungs, kidneys, brain, heart)

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Clinical Features

General Symptoms

• Fever, chills, rigors

• Rapid heart rate (tachycardia)

• Rapid breathing (tachypnoea)

• Confusion or altered mental state

• Weakness, malaise

Signs of Organ Dysfunction

• Hypotension (SBP <100 mmHg or MAP <65 mmHg)

• Reduced urine output (<0.5 mL/kg/h)

• Low oxygen saturation

• Jaundice

• Skin mottling or cyanosis

Septic Shock

• Persistent hypotension despite adequate fluid resuscitation

• Elevated serum lactate (>2 mmol/L)

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Diagnosis

• Clinical recognition using Sepsis-3 criteria: infection + SOFA score increase ≥2 points

• qSOFA bedside assessment: RR ≥22/min, altered mentation, SBP ≤100 mmHg

• Laboratory tests: CBC, CRP, lactate, blood cultures, renal/liver function tests, coagulation profile

• Imaging to locate source of infection (X-ray, ultrasound, CT)

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Treatment

Immediate Management (within 1 hour — “Sepsis 6” bundle)

1. Oxygen therapy to maintain SpO₂ >94%

2. Blood cultures before antibiotics

3. Broad-spectrum antibiotics (empirical) within 1 hour

   • Examples: Piperacillin-tazobactam 4.5 g IV every 6–8 hours OR Meropenem 1 g IV every 8 hours

4. IV fluids (30 mL/kg crystalloid bolus)

5. Measure lactate and repeat if elevated

6. Monitor urine output with catheter

Ongoing Care

• Source control: drain abscess, remove infected catheter

• Vasopressors (e.g., norepinephrine starting at 0.05–0.1 mcg/kg/min) if hypotension persists

• Organ support: mechanical ventilation, renal replacement therapy if indicated

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Prevention

• Timely treatment of infections

• Strict aseptic technique in hospital procedures

• Vaccination against pneumonia and influenza in high-risk patients

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Quick-Reference Clinical Chart — Sepsis

Feature	Details
Definition	Life-threatening organ dysfunction due to dysregulated infection response
Common Sources	Pneumonia, urinary tract infection, abdominal infection, skin infection
Causative Agents	E. coli, S. aureus, S. pneumoniae, Candida spp.
Risk Factors	Extremes of age, immunosuppression, chronic illness, recent surgery
Early Signs	Fever, tachycardia, tachypnoea, confusion
Severe Signs	Hypotension, oliguria, hypoxia, jaundice, mottled skin
Diagnosis	Clinical + SOFA ≥2, qSOFA, labs (CBC, lactate, cultures)
Immediate Treatment	Oxygen, blood cultures, broad-spectrum IV antibiotics (e.g., piperacillin-tazobactam 4.5 g IV q6–8h), IV fluids (30 mL/kg), lactate monitoring, urine output
Advanced Treatment	Vasopressors if needed, source control, organ support
Prognosis	Depends on speed of recognition and treatment; high mortality if delayed