Hypovolaemic shock Hypovolaemic shock is caused by an inadequate intravascular volume, which can be caused by loss of blood or other body fluids (McLuckie,2003).If the fluid loss is less than 750ml,the patient will usually present with a compensated picture in which the body tries hard to make up for the loss of fluid in the system (McLuckie, 2003). Compensation occurs by an increase in heart rate and systemic vasoconstriction.These two mechanisms maintain MABP in order to optimize perfusion to vital organs such as the brain and the heart.They are triggered by an increase in sympathetic activity and the release of catecholamines (adrenaline and noradrenaline) (Tortora and