What is the difference between sepsis and septic shock (Systemic Inflammatory Response Syndrome due to infection)?

From the Guidelines

Sepsis and septic shock are two distinct conditions that require prompt and effective treatment, with septic shock being a more severe form of sepsis that requires immediate attention to prevent high mortality rates. Sepsis is a life-threatening organ dysfunction caused by a dysregulated host response to infection, characterized by fever or hypothermia, tachycardia, tachypnea, and altered mental status, along with laboratory findings like leukocytosis or leukopenia 1. Septic shock is a more severe form of sepsis with profound circulatory, cellular, and metabolic abnormalities that substantially increase mortality risk. The key distinguishing feature of septic shock is persistent hypotension requiring vasopressors to maintain a mean arterial pressure (MAP) ≥65 mmHg despite adequate fluid resuscitation, along with serum lactate >2 mmol/L 1.

Treatment Approach

The treatment approach for both sepsis and septic shock includes:

• Early administration of broad-spectrum antibiotics, such as piperacillin-tazobactam 4.5g IV q6h, meropenem 1g IV q8h, or ceftriaxone 2g IV daily plus vancomycin 15-20mg/kg IV q8-12h, with antibiotic selection based on suspected source and local resistance patterns 1
• Fluid resuscitation with crystalloids (30mL/kg within the first 3 hours) is essential for both conditions 1
• Septic shock additionally requires vasopressors, with norepinephrine (starting at 0.05-0.1 mcg/kg/min, titrated to effect) as the first-line agent 1

Antimicrobial Therapy

The administration of effective IV antimicrobials within the first hour of recognition of septic shock and severe sepsis without septic shock is crucial. The initial empiric anti-infective therapy should include one or more drugs that have activity against all likely pathogens (bacterial and/or fungal or viral) and that penetrate in adequate concentrations into tissues presumed to be the source of sepsis 1. The antimicrobial regimen should be reassessed daily for potential de-escalation 1.

Key Considerations

• The selection of empiric antimicrobial therapy depends on complex issues related to the patient’s history, clinical status, and local epidemiologic factors 1
• The occurrence of more severe illness (e.g., septic shock) may be intrinsically associated with a higher probability of resistant isolates due to selection in failure to respond to earlier antimicrobials 1
• Collaboration with antimicrobial stewardship programs is encouraged to ensure appropriate choices and rapid availability of effective antimicrobials for treating septic patients 1

From the Research

Definition and Clinical Presentation

• Sepsis is a complication of severe infection characterized by a systemic inflammatory response 2
• Septic shock is the most severe form of sepsis, characterized by persistent hypotension despite fluid resuscitation and the presence of tissue hypoperfusion 3
• The clinical presentation of sepsis is highly variable depending on the etiology, with fever often being the first manifestation 2

Mortality Rates

• Mortality rates from sepsis range between 25% to 30% for severe sepsis and 40% to 70% for septic shock 2
• Delays in the diagnosis and initiation of treatment of septic shock are associated with increasing risk for mortality 3

Treatment and Management

• Early goal-directed therapy completed within the first six hours of sepsis recognition significantly decreases in-hospital mortality 2
• Initial management includes respiratory stabilization followed by aggressive fluid resuscitation, and vasopressor therapy is indicated when fluid resuscitation fails to restore adequate mean arterial pressure and organ perfusion 2, 3
• Early antibiotic therapy can improve clinical outcomes, and should be given within one hour of suspected sepsis 2
• The choice of antibiotic, such as meropenem versus piperacillin-tazobactam, may impact clinical outcomes in critically ill patients with sepsis and septic shock 4, 5

Importance of Timely Intervention

• Timely initiation of evidence-based protocols should improve sepsis outcomes 2
• Rapid initiation of appropriate antibiotic therapy is essential, as inadequate therapy early during septic shock has been shown to increase the risk of mortality 5
• Early identification and management of patients with severe sepsis and septic shock in the emergency department can significantly improve patient outcomes 6