What causes sepsis?

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Last updated: March 16, 2025View editorial policy

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From the Guidelines

Sepsis is caused by a dysregulated host response to an infection, which can lead to life-threatening organ dysfunction, as defined by the Third International Consensus Definitions for Sepsis and Septic Shock (Sepsis-3) 1.

Causes of Sepsis

The causes of sepsis can be attributed to various factors, including:

  • Infections from bacteria, viruses, fungi, or parasites, with bacterial infections being the most common cause
  • Common infection sites such as the lungs (pneumonia), urinary tract, skin, and abdomen
  • Risk factors that increase the likelihood of developing sepsis, including weakened immune systems, elderly, infants, chronic medical conditions, and individuals who have recently undergone surgery or have invasive medical devices

Pathogenesis of Sepsis

When an infection occurs, the body releases chemicals into the bloodstream to fight it, but in sepsis, these chemicals trigger widespread inflammation that can damage multiple organ systems, leading to organ dysfunction and potentially death.

Importance of Early Recognition and Treatment

Early recognition and treatment of sepsis with appropriate antibiotics, intravenous fluids, and organ support is crucial for survival, as delayed treatment can lead to increased morbidity and mortality.

Treatment Approach

Treatment typically involves broad-spectrum antibiotics initially, followed by more targeted antibiotics once the specific pathogen is identified, along with supportive care to maintain organ function while the body fights the infection, as recommended by the Surviving Sepsis Campaign: International Guidelines for Management of Sepsis and Septic Shock: 2016 1.

From the Research

Causes of Sepsis

  • Sepsis is a life-threatening disease caused by a systemic infection that triggers a dysregulated immune response 2, 3, 4, 5, 6
  • The pathogenesis of sepsis is intricate and involves a complex interplay of pro- and anti-inflammatory mechanisms that can lead to excessive inflammation, immunosuppression, and potentially long-term immune disorders 2
  • Immunosuppression is recognized as a predisposing factor for increased susceptibility to secondary infections and mortality in patients 2, 5
  • Disbalances of the immune response play an important role in the pathophysiology of sepsis, with patients developing simultaneously or concomitantly states of systemic or local hyperinflammation and immunosuppression 3, 4

Immune Response in Sepsis

  • The immune response caused by the pathogen is complex, resulting in a dysregulated innate and adaptive immune response that, if not promptly controlled, can lead to excessive inflammation, immunosuppression, and failure to re-establish immune homeostasis 4
  • Sepsis-induced immunosuppression is characterized by the release of anti-inflammatory cytokines, abnormal death of immune effector cells, hyperproliferation of immune suppressor cells, and expression of immune checkpoints 5
  • The impaired immune response in patients with sepsis and the potential immunotherapy to modulate the immune response causing excessive inflammation or enhancing immunity suggest the importance of demonstrating individualized therapy 4

References

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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