SEPSIS
Sepsis is characterized by life-threatening organ dysfunction due to dysregulation of the host’s immune and metabolic response to bacterial infection. Innate immunity involving cells (macrophages, neutrophils, dendritic and natural killer cells) and humoral factors (complement, antibodies and acute phase proteins) is activated by pathogen entry and the bacterial infection can rapidly progress to sepsis. Sepsis is a leading cause of morbidity and mortality worldwide and in India.
There are 4 distinct stages of sepsis:
1. SIRS (Systemic Inflammatory Response Syndrome)
SIRS is the earliest stage and represents a non-specific, systemic activation of the innate immune system triggered by infection or noninfectious insults such as trauma, pancreatitis, burns, etc.
2. Sepsis
Sepsis occurs when SIRS is specifically triggered by infection and the immune response becomes dysregulated. It is defined as the presence of sepsis and refractory hypotension, i.e., systolic blood pressure less than 90 mm Hg, mean arterial pressure less than 65 mm Hg or a decrease of 40 mm Hg in systolic blood pressure compared to baseline unresponsive to a crystalloid fluid challenge of 20 to 40 mL/kg.
3. Severe sepsis
Severe Sepsis is defined by sepsis accompanied by acute organ dysfunction resulting from profound inflammatory and microcirculatory disturbances.
4. Septic shock
This is the most severe and life-threatening stage. In effect, the body’s response to combat infection causes multiple organ damage and failure, which leads to death within hours or results in long-lasting effects, if not treated quickly.
There are different types of sepsis based on the people that are affected:
1. Neonatal sepsis
Neonatal sepsis is a life-threatening bloodstream infection in newborns within the first 28 days of life, which can lead to shock, multiple organ failure and death if not treated promptly. It is categorized as early-onset (within 72 hours of birth) or late-onset (after 72 hours).
2. Maternal sepsis
Maternal sepsis is a life-threatening organ dysfunction caused by infection during pregnancy, childbirth or postpartum, a leading cause of maternal death.
3. Geriatric sepsis
Sepsis in the geriatric population is a critical, life-threatening condition with higher incidence and mortality due to age-related immune decline and chronic comorbidities.
4. Hospital acquired sepsis
Hospital-Acquired Sepsis (HOS) is a severe infection-triggered immune response that develops during a hospital stay (usually >48 hours), often linked to medical devices (catheters, ventilators) and multidrug-resistant organisms (MDROs).
5. Urosepsis
Urosepsis, as the name implies, is sepsis originating from the urogenital tract. Urosepsis is sepsis caused by infections of the urinary tract, including cystitis or lower urinary tract and bladder infections and pyelonephritis, or upper urinary tract and kidney infections.
6. Abdominal sepsis
Abdominal sepsis is a severe, life-threatening condition where an infection in the abdomen (like from a perforated gut, appendix or diverticulitis) triggers the body's systemic response, causing organ dysfunction, severe inflammation (peritonitis) and potentially septic shock.
Survival from infections can be influenced by the capacity of the host immune system in identifying microbial pathogens and triggering an immediate and effective response. Early diagnosis of sepsis is critical for better disease outcome.
The following is the key laboratory marker used to evaluate and diagnose sepsis:
