What is systemic inflammatory response syndrome (SIRS)?

Systemic inflammatory response syndrome (SIRS)

SIRS is defined as a systemic response to a non-specific infectious or non-infectious insults such as from burns, pancreatitis, an autoimmune disorder, ischemia, or trauma. 

The presence of two or more of the following clinical criteria help establish the diagnosis of SIRS: 

• Body temperature higher than 38°C (100.4°F) or lower than 36°C (96.8°F) 
• Heart rate faster than 90 beats per minute
• Respiratory rate more than 20 breaths per minute or hyperventilation with an arterial carbon dioxide tension (PaCo2) less than 32 mm Hg
• Abnormal white blood cell count (greater than 12,000/ mcL or less than 4000/mcL or greater than 10% immature [band] forms)

N.B: When a source of infection is confirmed, SIRS is categorized as sepsis

Source:

• CURRENT Medical Diagnosis & Treatment 2018; page 502
• Robbins Basic Pathology 10th Edition; page: 58 (Fig 3.1) & 60