What is sepsis?

What is Sepsis?

Sepsis is a life-threatening organ dysfunction caused by a dysregulated host response to infection, characterized by an increase in the Sequential Organ Failure Assessment (SOFA) score of 2 points or more. 1

Definition and Pathophysiology

Sepsis involves an abnormal immune response to infection that damages the body's own tissues and organs. This dysregulated host response leads to organ dysfunction that can rapidly progress to life-threatening conditions 1. The pathophysiological mechanisms include:

• Endothelial dysfunction
• Coagulation abnormalities
• Alterations in cell function
• Dysregulated cardiovascular responses 2

Clinical Identification and Diagnosis

Organ Dysfunction Assessment

The SOFA score is the primary tool for identifying organ dysfunction in sepsis. It evaluates six organ systems:

• Respiratory
• Cardiovascular
• Hepatic
• Coagulation
• Renal
• Neurological

An increase of ≥2 points in the SOFA score indicates organ dysfunction associated with sepsis 1.

Screening Tools

Several tools help identify patients at risk of sepsis:

1. qSOFA (quick SOFA): A bedside screening tool evaluating three parameters:

   • Altered mental status
   • Systolic blood pressure ≤100 mmHg
   • Respiratory rate >22/min

   A score ≥2 indicates high risk of sepsis, though it has lower sensitivity (31-36%) but higher specificity (78-90%) 1.

2. NEWS2 (National Early Warning Score 2): Evaluates six physiological parameters with scores ranging from 0 (very low risk) to ≥7 (high risk) 1.

Septic Shock

Septic shock represents a more severe evolution of sepsis, characterized by:

• Circulatory, cellular, and metabolic abnormalities
• Need for vasopressors to maintain mean arterial pressure ≥65 mmHg
• Serum lactate level >2 mmol/L despite adequate fluid resuscitation
• Hospital mortality rates exceeding 40% 1

Management Approach

Management is stratified based on risk assessment:

• High-risk patients (qSOFA ≥2 or NEWS2 ≥7):

  • Broad-spectrum antibiotics within 1 hour
  • IV fluid bolus (30 ml/kg crystalloid) for hypotension
  • Monitoring every 30 minutes 1

• Moderate-risk patients (NEWS2 5-6):

  • Antibiotics within 3 hours
  • IV fluids as needed
  • Monitoring hourly 1

• Low-risk patients (NEWS2 1-4):

  • Antibiotics within 6 hours
  • Monitoring every 4-6 hours 1

Important Clinical Considerations

• Early recognition and prompt management are crucial for improving outcomes 3
• Antimicrobials should be administered as soon as possible, as delays are associated with increased mortality 3
• Fluid management should avoid fluid overload in patients with generalized peritonitis 1
• Norepinephrine is the recommended first-line vasopressor for septic shock 3

Evolution of Sepsis Definition

The definition of sepsis has evolved significantly over time:

• 1991: Initial definition based on systemic inflammatory response syndrome (SIRS)
• 2001: Revised to incorporate threshold values for organ damage
• 2016: Current definition focusing on life-threatening organ dysfunction and eliminating mention of SIRS 4

This evolution reflects improved understanding of sepsis pathophysiology and aims to better identify patients at risk of poor outcomes.