Table 1. Clinical Signs of Shock

	Class 1	Class 2	Class 3	Class 4
Blood Loss Volume (mls) in adult	750mls	800 - 1500mls	1500 - 2000mls	>2000mls
Blood Loss % Circ. blood volume	<15%	15 - 30%	30 - 40%	>40%
Systolic Blood Pressure	No change	Normal	Reduced	Very low
Diastolic Blood Pressure	No change	Raised	Reduced	Very low / Unrecordable
Pulse (beats /min)	Slight tachy- cardia	100 - 120	120 (thready)	>120 (very thready)
Capillary Refill	Normal	Slow (>2s)	Slow (>2s)	Undetectable
Respiratory Rate	Normal	Normal	Raised (>20/min)	Raised (>20/min)
Urine Flow (mls/hr)	>30	20 - 30	10 - 20	0 - 10
Extremities	Normal	Pale	Pale	Pale & cold
Complexion	Normal	Pale	Pale	Ashen
Mental state	Alert, thirsty	Anxious or agressive, thirsty	Anxious or agressive or drowsy	Drowsy, confused or unconscious