Introduction

Sepsis and septic shock represent critical medical emergencies characterized by a high probability of mortality if left untreated. This condition impacts multiple organ systems through an inflammatory response, leading to complications like capillary leak, hypovolemia, decreased cardiac output, and hypotension, which can result in renal, heart, and brain failure, and stress on the endocrine system. The complexity of sepsis and its potential for rapid deterioration necessitates prompt recognition, efficient assessment, and aggressive treatment​​.

Revised guidelines in 2016 (Sepsis-3) redefined sepsis as life-threatening organ dysfunction caused by a dysregulated host response to infection. This redefinition combined previous categories of sepsis and severe sepsis into one. Septic shock now denotes sepsis with persistent hypotension requiring vasopressors and elevated serum lactate levels despite adequate fluid resuscitation​​.

Sepsis continues to be a major healthcare burden, with a significant increase in hospitalizations and mortality rates as high as 50.7% in septic shock cases. The financial implications are substantial, with the cost of hospitalization due to sepsis rising dramatically, making it one of the most expensive conditions treated in U.S. hospitals​​.

Sepsis Definitions

Sepsis

Sepsis is now defined as a life-threatening organ dysfunction caused by a dysregulated host response to infection. This modern definition reflects an understanding that sepsis is not just an infection, but a severe health condition where the body’s response to the infection causes damage to its own tissues and organs. The current definitions emphasize the severity of organ dysfunction in sepsis and its potential fatal outcomes (Srzić, Nesek Adam, & Tunjić Pejak, 2022).

Severe Sepsis

The term “severe sepsis” has been eliminated from the latest definitions, as recent understanding suggests that all sepsis is inherently severe. Previous classifications categorized severe sepsis as sepsis with acute organ dysfunction, but current perspectives integrate organ dysfunction into the fundamental definition of sepsis. This change acknowledges that sepsis is always a serious condition requiring immediate and effective treatment (Coopersmith & Nugent, 2020).

Septic Shock

Septic shock is a subset of sepsis in which particularly profound circulatory, cellular, and metabolic abnormalities are associated with a higher risk of mortality than with sepsis alone. It is characterized by a drop in blood pressure that decreases tissue perfusion pressure, causing hypoxia. Septic shock can be identified clinically by the requirement of vasopressors to maintain a mean arterial pressure of 65 mm Hg or greater and serum lactate levels greater than 2 mmol/L despite adequate volume resuscitation (Srzić, Nesek Adam, & Tunjić Pejak, 2022).

Related Terminology

• Systemic Inflammatory Response Syndrome (SIRS): Previously used to describe the inflammatory state resulting from infection, SIRS criteria are no longer central to the definition of sepsis. The shift away from SIRS criteria to SOFA (Sequential Organ Failure Assessment) scores in defining sepsis aligns with the focus on organ dysfunction (Coopersmith & Nugent, 2020).
• Organ Dysfunction: A crucial aspect of sepsis, organ dysfunction can manifest in various forms such as renal failure, respiratory failure, altered mental status, and cardiovascular instability. It’s the severity of organ dysfunction that distinguishes sepsis from less severe infections (Chiu & Legrand, 2021).

References

• Srzić, I., Nesek Adam, V., & Tunjić Pejak, D. (2022). SEPSIS DEFINITION: WHAT’S NEW IN THE TREATMENT GUIDELINES. Acta Clinica Croatica, 61, 67-72. Link to source
• Coopersmith, C., & Nugent, K. (2020). How do I identify the patient with “sepsis”? [Publisher]. Link to source
• Chiu, C., & Legrand, M. (2021). Epidemiology of sepsis and septic shock. Current Opinion in Anaesthesiology