Rapid fluid resuscitation of the hypovolemic patient after abdominal trauma is significantly enhanced by which of the following?
Rapid fluid administration is often the key to successful trauma resuscitation. Some of the important factors affecting the rate of fluid resuscitation include the diameter of the intravenous tubing, the size and length of the venous cannulae, the fluid viscosity, and the site of administration. According to Poiseuille's law, flow is proportional to the fourth power of the radius of a catheter and inversely proportional to its length. Therefore, the shorter a catheter and the larger its diameter, the faster one can infuse a solution through it. Central venous placement alone does not assure rapid flow. Importantly, the diameter of the intravenous tubing employed may be the rate-determining factor in fluid delivery: blood-infusion tubing allows twice the flow of standard intravenous tubing and should be used when rapid fluid resuscitation is needed. Any patient who is suspected of having a major abdominal injury should immediately have at least two short, large-bore (16-gauge or larger) intravenous cannulae placed in peripheral veins. Longer, smaller catheters, such as standard 18-gauge central venous catheters, may take more time to place and will have lower flow rates. Once fluid resuscitation is under way, one may elect to place an 8- or 9-French pulmonary artery catheter-introducer via a central venous approach for further volume administration, as well as for measurement of central venous pressure or for Swan-Ganz catheter insertion. Lower-extremity venous cannulae, placed by saphenous vein cutdown or percutaneously into the femoral veins, are no longer advised as primary access for patients with abdominal trauma, since possible disruption of iliac veins or the inferior vena cava will render volume infusion ineffective. Studies have demonstrated that the flow rate of cold whole blood is roughly two-thirds that of whole blood at room temperature. Diluting and warming the blood by "piggybacking" it into infusion lines that are delivering crystalloid will decrease the blood's viscosity, enhance flow, and minimize hypothermia.
Placement of long 18-gauge subclavian vein catheters
Placement of percutaneous femoral vein catheters
Bilateral saphenous vein cutdowns
Placement of short, large-bore percutaneous peripheral intravenous catheters
Trauma