About 3,000-4,000 cc of Ringer's lactate seems reasonable. Several clinical parameters are utilized by the medical officer in determining the casualty's response to the therapeutic intervention. Assessment of clinical response can be made on the basis of changes in blood pressure, pulse rate, capillary refill, urine output, and mental status. Where large volumes of fluid and blood are required, the progress of therapy is facilitated by central venous pressure monitoring. The centrally-placed catheter affords all accurate measure of the right heart's volume requirement and its ability to accept additional fluid loading.
Serial measurements are clearly of greater value than a single determination.
Sophisticated systems that measure cardiac output and the pulmonary artery wedge pressure do not add a great deal to the early treatment or treatment assessment of the combat casualty. Blood transfusion is all integral part of the resuscitation of casualties presenting with Classes III and IV hemorrhages and in those with continuing hemorrhage. Whole blood is preferred due to its lower viscosity, faster infusibility and potential provision of some of the clotting factors. Prior to hospital arrival, a more forward echelon may have already infused low-titer type O blood. Female casualties who require the immediate use of type O blood should be given Rh-negative, if available, to avoid the potential of future problems associated with sensitization.