From the Guidelines
SIRS, sepsis, and septic shock are defined as a progressive spectrum of inflammatory responses to infection, with SIRS characterized by at least two of the following criteria: temperature >38°C or <36°C, heart rate >90 beats/minute, respiratory rate >20 breaths/minute or PaCO2 <32 mmHg, and white blood cell count >12,000/mm³, <4,000/mm³, or >10% immature bands, as stated in the 2016 study 1.
Definitions
- SIRS is characterized by at least two of the following criteria:
- Temperature of >38 °C or <36 °C
- Heart rate of >90 beats per minute
- Respiratory rate of >20 breaths per minute or partial pressure of CO2 of <32 mmHg
- White blood cell count of >12,000 per ml or <4,000 per ml, or >10% immature (band) forms
- Sepsis is defined as a life-threatening organ dysfunction caused by a dysregulated host response to infection, which can be clinically represented by an increase in the SOFA score of 2 points or more, as defined in the 2017 study 1.
- Septic shock is defined as a subset of sepsis in which particularly profound circulatory, cellular, and metabolic abnormalities are associated with higher risk of mortality than with sepsis alone, and can be clinically identified by requirement for vasopressors to maintain a mean arterial pressure of 65 mmHg or greater and serum lactate level less than 2 mmol/L (>18 mg/dL) in the absence of hypovolemia, as stated in the 2017 study 1.
Management
- Management of sepsis requires prompt recognition, early administration of broad-spectrum antibiotics, aggressive fluid resuscitation, source control, and vasopressor support if hypotension persists.
- The initial hemodynamic resuscitation should be achieved within 3 h, with a goal of restoring a mean arterial pressure of 65 to 70 mmHg, as recommended in the 2017 study 1.
- Norepinephrine is the first-line vasopressor agent used to correct hypotension in the event of septic shock, as it is more efficacious than dopamine and effective for reversing hypotension in patients with septic shock, as stated in the 2017 study 1.
From the Research
Definition of SIRS, Sepsis, and Septic Shock
- The Systemic Inflammatory Response Syndrome (SIRS) is characterized by a dysregulated host response to infection, leading to inflammatory damage to nearly every organ system 2.
- Sepsis is a life-threatening syndrome that occurs when the body's response to an infection damages its own tissues and organs 3, 2.
- Septic shock is a subset of sepsis with associated circulatory and cellular/metabolic dysfunction associated with a greater risk of mortality than sepsis alone 3, 2.
Diagnostic Criteria
- The definition of SIRS, sepsis, and septic shock has evolved over time, with the third consensus (Sepsis-3) withdrawing the use of SIRS as a diagnostic pillar 4.
- The frequency of SIRS, sepsis, and septic shock in critically injured patients has been studied, with 87.8% of patients fulfilling the SIRS criteria, and 20.2% meeting the criteria for septic shock 5.
Clinical Implications
- Early recognition and treatment of sepsis and septic shock are essential to reducing organ system injury and mortality 3, 2.
- The use of antibiotics, fluids, and vasopressors is critical in the management of sepsis and septic shock, with timely and appropriate antibiotic therapy being the most important determinant of survival 3, 2, 6.