sensation or pain when a sharp object is gently applied to the skin. Administering local anesthesia is similar except you are anesthetizing nerves immediately adjacent to where you will be working instead of nerve trunks. There are two generally accepted methods of infiltrating the anesthesia. One is through the skin surrounding the margin of the wound and the other is through the wound into the surrounding tissue. In either case, sufficient quantities must be infiltrated to effect anesthesia approximately ½ inch around the wound, taking care not to inject into a vein or artery. CAUTION: The maximum recommended amount of Xylocaine to be used is 50 cc for a 1% solution or the equivalent. General Principles of Wound Suturing Wounds are closed either primarily or secondarily. A primary closure takes place within a short time of when the wound occurs, and it requires minimal cleaning and preparation. A secondary closure, on the other hand, occurs when there is a delay of the closure for up to several days after the wound's occurrence. A secondary closure requires a more complex procedure. Wounds 6 to 14 hours old may be closed primarily if they are not grossly contaminated and are meticulously cleaned. Wounds 14 to 24 hours old should not be closed primarily. When reddening and edema of the wound margins, discharge of pus, persistent fever, or toxemia are present, do not close the wound. Do not use a primary closure for a large, gaping, soft-tissue wound. This type of wound will require warm dressings and irrigations, along with aseptic care for 3 to 7 days to clear up the wound. Then a secondary wound closure may be performed. The steps to perform a delayed wound closure are outlined below. 1. Debride the wound area and convert circular wounds to elliptical ones before suturing. Circular wounds cannot be closed with satisfactory cosmetic results. 2. Try to convert a jagged laceration to one with smooth edges before suturing it. Make sure that not too much skin is trimmed off; that would make the wound difficult to approximate. 3. Use the correct technique for placing sutures. The needle holder is applied at approximately one-quarter of the distance from the blunt end of the needle. Suturing with a curved needle is done toward the person doing the suturing. Insert the needle into the skin at a 90 angle, and sweep it through in an arclike motion, following the general arc of the needle. 4. Carefully avoid bruising the skin edges being sutured. Use Adson forceps and very lightly grasp the skin edges. It is improper to use dressing forceps while suturing. Since there are no teeth on the grasping edges of the dressing forceps, the force required to hold the skin firmly may be enough to cause necrosis. 5. Do not put sutures in too tightly. Gentle approxi- mation of the skin is all that is necessary. Remember that postoperative edema will occur in and about the wound, making sutures tighter. Figure 4-33 illustrates proper wound-closure techniques. 6. If there is a significant chance that the sutured wound may become infected (e.g., bites, delayed closure, gross contamination), place an iodoform (anti-infective) in the wound. Or place a small rubber drain in the wound, and remove the drain in 48 hours. 7. When suturing, the best cosmetic effect is obtained by using numerous interrupted simple sutures placed 1/8 inch apart. Where cosmetic result is not a consideration, sutures may be slightly farther apart. Generally, the distance of the needle bite from the wound edges should be equal to the distance between sutures. 8. When subcutaneous sutures are needed, it is proper to use 4-0 chromic catgut. 9. When deciding the type of material to use on skin, use the finest diameter that will satis- factorily hold the tissues. Table 4-4 provides guidance as to the best suture to use in selected circumstances. 10. When cutting sutures, subcutaneous catgut should have a 1/16-inch tail. Silk skin sutures should be cut as short as is practical for removal on the face and lip. Elsewhere, skin sutures may have longer tails for convenience. A tail over ¼ inch is unnecessary, however, and tends to collect exudate. 11. The following general rules can be used in deciding when to remove sutures: a. Face: As a general rule, 4 or 5 days. Better cosmetic results are obtained by removing every other suture and any suture with 4-44