Vascular loading in the first 24 hours following severe head injuries

The main goal at the acute phase of head injury is to prevent a decrease in blood pressure, which promotes cerebral ischemia. Volume loading is therefore frequently indicated. A normal or increased plasma osmolarity should be maintained. Thus hypotonic fluids should be avoided. Hyperglycaemia is also a risk factor for brain injury and glucose use has to be restricted in the first hours after trauma. Isotonic saline 0.9% is the first solution to be infused. Lactated Ringer solutions are mildly hypotonic as approximately 114 mL of free water is contained in each litre of the solution. Isotonic colloids are indicated to replace blood losses, but have no advantage over cristalloids, concerning the development of cerebral oedema. Fluid restriction minimally affects cerebral edema. Because of the severe consequences of hypovolaemia and hypotension, fluids should not be restricted until haemodynamic stability is achieved. Hypertonic fluids rapidly restore intravascular volume and decrease intracranial pressure. Although they probably have a place in prehospital intensive therapy, the demonstration of their benefit is still lacking. Monitoring of intravascular volume is essential. Continuous arterial pressure and central venous pressure monitoring are mandatory. New monitoring techniques as the measurement of systolic pressure variations or transoesophageal Doppler echocardiography will probably find a place in the management of trauma patients in the near future.