To begin preparation, inspect the vial. Do not administer if the product is discolored or if the vial has been frozen. Immediately before withdrawing contents from the vial, invert it to resuspend the particles. You may need to invert the vial several times if the content has settled.
To open the vial, place your thumb against the notch on the cap, flip the cap up, and remove the metal collar. Puncture the vial stopper once with a 25-gauge or larger needle. You may find it easier to withdraw the therapeutic with a larger needle. DO NOT puncture the vial multiple times. Use aseptic technique to sequentially attach and fill sterile syringes for dosing. Each syringe should be prepared for single patient use only. Discard the vial after all doses are withdrawn.
To administer NOCITA, calculate the dose volume for each injection to be used in the 4-point peripheral nerve block. Withdraw appropriate dose volume for each of the 4 injection sites on each forelimb.
You are now ready to administer NOCITA as peripheral nerve blocks to each forelimb.
[DOSE ADMINISTRATION]
For the procedure, we will use a 25-gauge needle to administer NOCITA. We begin administering the nerve block at the superficial branch of the radial nerve, starting with the left forelimb.
We find it is easier to keep the legs in the correct orientation to guide the injections if the cat is kept in sternal for the Point A injections. It helps to have an assistant hold the limb so taht there is a line from shoulder to elbow to carpus but be sure they aren't rotating the limb as there is a tendency to hold as though for venipuncture.
Looking down onto the top of the forelimbs, find your landmarks for this injection: the antebrachiocarpal joint and the junction of the accessory cephalic and cephalic veins. The carpus should be at an angle to the table, not flat — the medial aspect will be slightly up off the table.
Flex and feel for the distal end of the radius using your thumb. Note the level of the joint line at the midpoint of the leg’s width when viewed in this position. With the bevel up, insert the needle, with care to remain in the subcutaneous space. Angle the needle medially, aiming for the junction of the accessory cephalic and cephalic veins. Advance the needle approximately 10 millimeters (less in smaller cats), being sure to remain in the subcutaneous space. Once the needle tip is 3 to 5 millimeters from the junction, aspirate and slowly inject NOCITA. You should see a bleb just under the skin.
Follow the same landmarks for the right forelimb — noting the midpoint of the limb’s width at the level of the antebrachiocarpal joint. Our perspective makes it appear that the needle entry isn’t centered, but the needle is correctly positioned.
The second block to be administered will be for the dorsal branch of the ulnar nerve. Run your thumb or forefinger distally along the lateral aspect of the carpus, feeling for a groove between the accessory carpal bone and the styloid process of the ulna — they create a bit of a “V” through which the nerve runs. The accessory carpal bone is in the base of the accessory carpal pad, which in some cats may be more proximal than you’d expect.
Approximately 3-5 millimeters distal to the base of the “V” made by this groove, insert the needle with the bevel up. Advance the needle subcutaneously until the tip is located at the midpoint of the groove. Aspirate and inject. For the right forelimb, we again feel between the two bones, aspirate and inject such that the bleb appears just proximal to the groove.
The third block to be administered is for the median nerve and superficial branch of the palmar branch of the ulnar nerve. For this block the needle will be inserted on the lateral side and advanced medially over the palmar aspect of the metacarpals.
Palpate the base of the first digit and note where the tip of the accessory carpal pad is located. It’s okay to press down gently, but don't push it toward the toes as this will alter the landmark. With the bevel up, insert the needle just lateral and distal to where the tip of the accessory carpal pad is located. Carefully advance the needle medially, aiming for the base of the first digit. The needle should be easily visible just under the skin.
Once the needle is advanced two-thirds the width of the limb, aspirate and inject two-thirds of the dose volume, then the remaining one-third as you slowly withdraw the needle. Aim to finish your injection when the tip is still a few millimeters from the entry point, to prevent leakage. Massage the area for 5 seconds.
For the right paw, once again find the base of the first digit. Applying gentle pressure to the accessory carpal pad, find the landmarks. Flex the toes back to keep the skin taut as you advance the needle just under the skin. Aspirate and inject. If the needle poked through the skin as it was advanced, a small amount may leak out of the hole, as seen here. You can gently apply pressure to this puncture as you massage.
The last block is administered at the deep branch of the palmar branch of the ulnar nerve. Identify the accessory carpal bone — at or just proximal to the base of the accessory carpal pad, on the lateral side. Approach the accessory carpal bone from the medial side, insert the needle into the skin with the bevel up, and advance 1-2 millimeters until it touches the bone. Rotate the syringe 90 degrees so the needle is redirected dorsally. Using the accessory carpal bone as a guide, advance the needle two to three millimeters until it penetrates the flexor retinaculum. Veterinarians report they feel a slight “pop” at least half the time. Aspirate and inject.
Find the accessory carpal bone on the right paw and repeat. For this block, take special note of the hand and needle positions for right versus left paws. The patient is now ready for surgery.