Sepsis is a condition that arises when the body's response to an infection injures its tissues and organs, sometimes progressing to septic shock. Multiple organ (lung, liver, and kidney) dysfunction is possible, which may result in death. Sepsis may be characterized by organ dysfunction, hypoperfusion, and hypotension, or just hypotension alone.
The U.S. Centers for Medicare and Medicaid Services (CMS) published its core measure and definition for sepsis, The Third International Consensus Definitions for Sepsis and Septic Shock (Sepsis-3), in 2016. For the past 20 years, Sepsis-1 (SEP-1) has been utilized in the measure. Although SEP-1 remains retroactively in use, SEP-3 is now the endorsed standard.
SEP-1 Definitions
Severe Sepsis/Septic Shock Early Management Bundle (SEP-1) defines severe sepsis as having a suspected source of clinical infection and two or more manifestations of systemic infection (using SIRS criteria) plus one or more organ dysfunction variables. SIRS criteria include:
- A body temperature >38°C (100.4°F) or <36°C (96.8°F)
- A heart rate >90 beats/minute
- Respiratory rate >20 breaths/minute
- An alteration in the white blood cell (WBC) picture, such as a count >12.0 × 103/mcL or <4.0 × 103/mcL or >10% immature neutrophils (leukocytosis)
According to SEP-1, variables of organ dysfunction leading to a diagnosis of severe sepsis include any one of the following:
- Lactate >2 mmol/L
- INR >1.5 or aPTT >60 seconds
- Platelet count <100,000 × 103/mcL
- Bilirubin >2 mg/dL
- Creatinine >2 mg/dL, or urine output <0.5 mL/kg/hr for 2 hours
- Systolic blood pressure (SBP) <90 mmHg, or mean arterial pressure <65 mmHg, or decrease in SBP >40 mmHg from last previously recorded "normal" for that patient
SEP-3 Definitions
Sepsis is defined as life-threatening organ dysfunction due to a dysregulated host response to infection.
- Sepsis clinical criteria: organ dysfunction is an increase of 2 points or more in the Sequential Organ Failure Assessment (SOFA) score. Here, SOFA assessment is utilized in place of SIRS. SOFA is a score obtained by the clinical providers.
- Patients with suspected infection who are likely to have a prolonged ICU stay or to die in the hospital, presenting with two or more of the following:
- Hypotension: Systolic Blood Pressure less than or equal to 100 mmHg
- Altered mental status: Generalized Consciousness Scale score less than 15
- Tachypnoea: Respiratory Rate greater than or equal to 22 breaths/minute
Septic shock is a subset of sepsis with underlying circulatory, cellular, and metabolic abnormalities that are profound and substantially increase mortality. Septic shock clinical criteria includes:
- Sepsis,
- Persistent hypotension requiring vasopressors to maintain Mean Arterial Pressure greater than or equal to 65 mm Hg, and
- Lactate greater than or equal to 2 mmol/L.
Note: As of the SEP-3 criteria publication, the term “severe sepsis” is no longer used.
1. Singer, M., Deutschman, C., Seymour, C., et al. (2016). The third international consensus definitions for sepsis and septic shock (Sepsis-3). JAMA. 315(8):801-810. doi:10.1001/jama.2016.0287
