Sepsis

Systemic inflammatory response syndrome (SIRS)

Definition

Sepsis is a severe illness caused by overwheming infection of the bloodstream by toxin-producing bacteria.

Causes, incidence, and risk factors

Sepsis is caused by bacterial infection that can originate anywhere in the body. Common sites include the following:

• The kidneys (upper urinary tract infection)
  
• The liver or the gall bladder
  
• The bowel (usually seen with Peritonitis)
  
• The skin (cellulitis)
  
• The lungs (bacterial pneumonia)
  

Meningitis may also be accompanied by sepsis. In children, sepsis may accompany infection of the bone (osteomyelitis). In hospitalized patients, common sites of infection include intravenous lines, surgical wounds, surgical drains, and sites of skin breakdown known as decubitus ulcers or bedsores.

The infection is often confirmed by a positive blood culture, though blood cultures may be negative in individuals who have been receiving antibiotics. In sepsis, blood pressure drops, resulting in shock. Major organs and systems, including the kidneys, liver, lungs, and central nervous system, stop functioning normally.

A change in mental status and hyperventilation may be the earliest signs of impending sepsis.

Sepsis is often life-threatening, especially in people with a weakened immune system or other medical illnesses.

Symptoms

• Fever or hypothermia (low body temperature)
  
• Hyperventilation
  
• Chills
  
• Shaking
  
• Warm skin
  
• Skin rash
  
• Rapid heart beat
  
• Confusion or delirium
  
• Decreased urine output
  

Signs and tests

• White blood cell count that is low or high
  
• Platelet count that is low
  
• Blood culture that is positive for bacteria
  
• Blood gases that reveal acidosis
  
• Kidney function tests that are abnormal (early in the course of disease)