SIRS

Table 1: SIRS[Ame92] is defined as the presence of two or more of the variables below

Variable	Abnormality
Temperature	$>$ 38 C or $<$ 36 C
Heart rate	$>$ 90 beats per minute
Respiratory rate	$>$ 20 breaths per minute or PaCO $<$ 32 mmHg ($<$ 4.3 kPa)
White cell count	$> 12 \times 10^9$ or $< 4 \times 10^9$ or $> 10\%$ immature (band) cells

The definition of SIRS has varied and most accepted definition is that given by the American College of Chest Physicians (ACCP)/ Society of Critical Care Medicine (SCCM)[Ame92], outlined in table 1.

In simple terms SIRS is defined as a syndrome characterised by the presence of two or more variables. This definition is fairly wide and all encompassing, indeed any sick surgical patient almost automatically has SIRS.