Brief overview
- SIRS criteria: Elevated body temperature (36 to 38 degrees Celsius), accelerated heart rate (at least 90 beats per minute), faster breathing (at least 20 breaths per minute), increased or decreased white blood cell count (leukocyte count: ≥12000/microliter or ≤4000/microliter).
- Treatment and prognosis: hydration by IV, thromboprophylaxis, analgesics, surgery for organ failure
- Causes: Burns, injuries, organ damage and inflammation, undersupply of organs and tissues, hemorrhage, allergies
When is SIRS present?
According to a somewhat outdated definition that was in effect until 2007, physicians referred to SIRS (systemic inflammatory response syndrome) when there is an inflammatory response of the entire body without a specific pathogen being proven or suspected as the trigger.
However, this classification is insufficient, which is why the German Interdisciplinary Association for Intensive Care and Emergency Medicine (DIVI) and the German Sepsis Society (DSG) have adapted the definition for SIRS. Accordingly, the terms SIRS and sepsis are to be considered together and do not indicate different diseases. A distinction is now made between SIRS with infection and without organ complication (sepsis) and SIRS with infection and with organ complication (“severe” sepsis).
The previously established SIRS criteria continue to apply, including for more detailed assessment of the severity of sepsis, but primarily in ill patients 16 years of age or older.
What are SIRS criteria?
Physicians speak of SIRS when at least two of the following four SIRS criteria are met:
- Fever (38 degrees Celsius) or hypothermia (36 degrees Celsius), measured rectally or via catheter probe in a blood vessel or the urinary bladder
- Rapid breathing (tachypnea) with more than 20 breaths per minute or hyperventilation (measurable by the CO2 content in the blood)
- White blood cells in the blood increased (leukocytosis: ≥12000/microliter) or decreased (leukopenia: ≤4000/microliter)
What are the treatment and prognosis for SIRS?
Primarily, physicians attempt to stabilize the circulation with infusions and, if necessary, vasoconstrictive agents (vasopressors) in the treatment of SIRS, similar to the treatment of sepsis.
In addition to supplementary standard therapies such as thrombosis prophylaxis and pain therapy, doctors consider surgery if the trigger of SIRS is, for example, organ damage or a burn. This is because for the sustained treatment of SIRS, it is important to track down its trigger and, if possible, eliminate it.
Read more about the treatment and course of sepsis in the article Blood Poisoning.
What triggers SIRS?
There are many triggers of SIRS or sepsis. They include, but are not limited to:
- Burns
- Injuries
- Major organ damage
- Severe allergic reactions (anaphylaxis)
- Organ inflammation such as pancreatitis
- Severe bleeding
- Insufficient oxygen supply to tissues or organs (ischemia) such as a stroke or heart attack
Examinations and diagnosis
Read more about how SIRS or sepsis is diagnosed in the article Blood Poisoning.
