Definition : inadequate tissue and organ perfusion to meet metabolic demands leading to
eventual global cellular hypoxia.
Hypotension: SBP < 90mmH or MAP <60mmHg or reduction in SBP >30mmHg from baseline
Pathophysiology of Shock
i. MAP ∝ CO x SVR
ii. CO = SV x HR
iii. SV ∝ preload, afterload and myocardial contractility
iv. → MAP ∝ HR, preload, afterload, contractility
With systemic hypotension = release of catecholamines, aldosterone, renin and cortisol which
act together to increase HR, preload, afterload and contractility.
RECOGNITION OF SHOCK
Inadequate tissue perfusion
i. Skin – cold, pale, decreased capillary refill
ii. Renal – decreased urine output (<0.5ml/kg/hr)
iii. CNS – anxiety, confusion, lethargy
Increased sympathetic tone
i. Narrowed Pulse Pressure
ii. Tachycardia
ENDPOINT OF RESUSCITATIONS
- Normalization of BP, HR, Urine Output -> most patient (50-85%) still in “compensated” shock
- Serum markers – lactate (<2 mmol/L), base deficit (between -2 and +2) & gastric mucosa pH (7.30 – 7.35) are more appropriate end-points -> aim for normalization within 24hours
Types Of Shock
