To begin, insert a lubricated rectal probe to control the temperature of the anesthetized rat during surgery. After locating the jugular region in the lower right neck region of the anesthetized rat above the clavicle, use DeBakey Atraumatic Forceps to gently grasp the skin and make a precise incision with fine sharp scissors or a scalpel. Gently slash the tissue with standard pattern forceps.
Locate and gently liberate the jugular vein from its muscular compartment. Place a 4-0 silk suture thread to securely ligate the distal side of the jugular vein. Use the suture with the needle holders to tension the jugular vein.
Place a 4-0 suture on the proximal side of the jugular vein and prepare a surgeon knot without tightening it. Using Vannas micro dissecting scissors, make a small incision in the jugular vein. After carefully grasping the vein wall with small forceps, insert the PE50 catheter in the jugular vein.
Slightly advance the catheter, and to confirm its correct placement in the vein, draw a small amount of blood and re-inject it. Tighten the previously prepared knot to secure the catheter. Apply a drop of lidocaine to the incised area.
Cover the incision with a moist sterile gauze pad. Use DeBakey Atraumatic Forceps to grasp the skin of the Scarpa triangle on the left leg, and make an incision with fine sharp scissors or a scalpel. Gently dilacerate tissue with standard pattern forceps.
Locate the femoral triad and place one forceps under the triad. Then with a second standard pattern forceps, carefully separate the artery from the nerve and femoral vein. Place a 4-0 suture to ligate the femoral artery distally and take the suture with the needle holders to put the femoral artery in tension.
Now place a 4-0 suture on the proximal side of the femoral artery and prepare a surgeon knot without closing it. After clamping the artery, use Vannas micro dissecting scissors to make a transverse incision in the femoral artery. Grasp the artery wall with standard pattern forceps and cannulate the femoral artery with the catheter holding it with forceps.
Gently unclamp the artery and ensure that the blood is not flowing back into the catheter. If the signal is good, advance the catheter slightly into the artery and tighten the previously prepared surgeon knot. Administer heparin into the rat, and place a moistened sterile gauze pad over the incised area.
After 10 minutes of stabilization, record the basal hemodynamic values for five minutes. To induce hemorrhagic shock, use a one milliliter syringe to draw five milliliters of blood from the femoral artery over five minutes. Prepare a mix of 50%lactated Ringer solution and 50%collected blood at room temperature.
Place a two milliliter syringe filled with the mix at the end of the jugular vein cannula. For hemorrhagic shock maintenance, when mean arterial pressure exceeds 38 millimeters of mercury, withdraw 200 microliters of blood from the femoral artery. If pressure drops below 32 millimeters of mercury, inject 200 microliters of the 50%blood, 50%lactated Ringer's mixture through the jugular vein.
After sterile preparation of the tail with a gauze pad, use the tip of the needle to draw a blood drop from the end of the tail to measure peripheral blood lactate. Finally, resuscitate the rat with a lactated Ringer solution using a 20 milliliter syringe through the jugular catheter with a syringe pump.
