Assessment of hypovolaemia in the critically ill.

Assessment of the intravascular volume status of patients is one of the most challenging tasks for the intensive care clinician. It is also one of the most important skills in intensive care management as both hypervolaemia and hypovolaemia lead to increased morbidity and mortality. The assessment of hypovolaemic patients is aided by several clinical signs, laboratory investigations, and a multitude of haemodynamic monitoring systems. This review aims to outline the definitions, pathophysiology, and various assessment techniques (both old and new) employed by intensivists on the critically ill patient.