Definition of Sepsis

Sepsis is defined by the 1992 American College of Chest Physicians consensus criteria (sometimes referred to as the "Bone" criteria after the lead author).^[1]

The definition of Sepsis requires the presence of proven infection and two or more features of Systemic Inflammatory Response Syndrome (SIRS), namely:

• Fever or Hypothermia (Temperature over 38 or under 36 degrees Celcius)
• Tachypnea (Respiratory rate over 20)
• Tachycardia (Heart Rate over 90)
• Immune Dysregulation (White Blood Cell count less than 4000, greater than 12000, or greater than 10% immature forms)

Severe sepsis is a subset of sepsis that is characterized by organ dysfunction, and Septic Shock is defined as Severe Sepsis with hypotension unresponsive to appropriate amounts of fluid administration. These are discussed in more detail below.

An alternative classification of Sepsis uses the acronym PIRO to describe the condition.

PIRO refers to various aspects of sepsis, namely:

• Predisposition
  
• Insult/Infection
  
• Response
  
• Organ Dysfunction
  
  

^[2]
This classification may in future be used to aid risk stratification in patients admitted to the ICU with Sepsis. ^[3]

Diagnosis of Sepsis - Symptoms

Despite the relatively clear definition above, the diagnosis of Sepsis may be difficult in some patients, and is often delayed until late in the disease course. Patients may present with clear symptoms of infection, such as cough, sputum production and fever, or may be non-specifically unwell, with 'flu-like symptoms, malaise or diarrhoea.

Diagnosis of Sepsis - Signs

Clinical signs of sepsis may relate to the underlying infection, or to the physiological disturbance caused by Sepsis.

Investigation of Sepsis

Immediate Therapy including 6-hour Surviving Sepsis Campaign Care Bundle.

Subsequent Therapy including Surviving Sepsis Campaign 24-hour Care Bundle

Fluid Administration

Vasopressor and Inotrope Therapy

Rational and Timely Antibiotic Choice

Steroid Use in Sepsis

Glycaemic Control in Sepsis

Source Control

The Role of Invasive Monitoring in Sepsis

The role of Nutrition and Micronutrients in Sepsis

Critical illness myopathy and neuropathy and Sepsis

Recovery from Sepsis

Genetics of Sepsis - brief notes on previous and current studies

Statins and Sepsis - brief notes on what is currently known

Key Trials in Sepsis - brief notes on the key studies that informed the SSC guidelines

Early Goal Directed Therapy (EGDT) for Severe Sepsis and Septic Shock
Dr. Rivers, et al, in the November 8, 2001 edition of the New England Journal of Medicine detailed a series of actions that showed significant improvements in the mortality rate of patients with septic shock (46.5% mortality in standard treatment group, 30.5% mortality in EGDT group; Number Needed to Treat [NNT] is 6.25).

The pathway outlined in the article includes the following:

• Initiate antibiotics (if bacterial meningitis is suspected, give Decadron 0.15 mg/kg IV prior to antibiotics).
• Placement of a central vein catheter to measure central venous pressure (CVP).
• Give 500cc boluses of crystalloid every 30 minutes until the CVP is normal (8-12).
• After CVP normalized, if patient remains hypotensive, start pressors to keep the mean arterial pressure (MAP) 65-90.
• Transfuse the patient as needed to keep the hematocrit > 30% to increase oxygen carrying capacity.
• Obtain central venous blood gas oxygen saturation. If VBG O2 < 70%, start dobutamine.
• If VBG O2 < 70% after starting dobutamine, paralyze and intubate the patient.

Also, if an abscess is present, early drainage is beneficial.

References:

1. ↑ ACCP-SCCM consensus conference on sepsis and organ failure. Bone RC, Sibbald WJ, Sprung CL. Chest. 1992;101;1481-3.
2. ↑ Predisposition, insult/infection, response, and organ dysfunction: A new model for staging severe sepsis. Rubulotta F, Marshall JC, Ramsay G, Nelson D, Levy M, Williams M. Crit Care Med. 2009;37:1329-35.
3. ↑ Sepsis mortality prediction based on predisposition, infection and response. Moreno RP, Metnitz B, Adler L, Hoechtl A, Bauer P, Metnitz PG; SAPS 3 Investigators. Intensive Care Med. 2008 Mar;34(3):496-504.