Description

Fluid resuscitation in acute care medicine remains controversial. Clinical recommendations should be based on an understanding of the pathophysiology of trauma and the composition of the various intravenous fluids available. The metabolic response to trauma results in sodium retention and water retention in excess of sodium. Currently available crystalloid solutions are not ideal, since 0.9% saline results in hyperchloraemic acidosis and Ringers lactate is hypotonic and may worsen the hypo-osmolar state associated with injury. Clear-cut advantages for the colloids have yet to be demonstrated. Current recommendations suggest that crystalloid administration should probably be limited to 23 litres of crystalloid and further volume replacement should be managed with colloid solutions. Red cell infusions, fresh frozen plasma and platelets should be administered to correct demonstrable deficits. The determination of plasma volume, and hence the judgement of the need for volume therapy remains controversial. Static haemodynamic measures including arterial blood pressure, pulmonary capillary wedge pressure and central venous pressure are limited in terms of their value in estimating volume requirements. No ideal measure against which to guide volume therapy exists, but dynamic measures of the response of stroke volume or pulse pressure variation to volume loading may offer good answers to the problem in the future.