Chapter Outline
Commonly Performed Clinical Procedures
This chapter illustrates some of the common procedures performed by physician assistant (PA) students and practicing PAs. It is not designed to be all-inclusive because there are many medical and surgical procedures not covered in this chapter. It is rather a primer for PA students and a refresher for practicing PAs for the procedures commonly performed throughout medical and surgical practices. Wound care, sutures, wound closures (including anesthetics used), wound dressing, universal precautions, and commonly performed procedures are covered. Words of advice for PA students include a willingness to learn any procedure presented during your education and volunteer to assist if you are not asked to perform the procedure. The old adage “see one, do one, teach one” holds quite true during your education and subsequent practice. The information within this chapter is designed to help you understand the aspects of performing these procedures.
The ability to perform clinical procedures is a necessary skill for PA students and practicing PAs alike. Procedures often provide valuable information that may aid in the diagnosis and treatment of a patient’s disease. No matter how routine and uncomplicated a clinical procedure may seem to a health care provider, it must always be regarded as a unique and personal experience for the patient.
Preparing the patient for the procedure both mentally and physically presents a challenge to all health care providers. Preparation skills must be developed and applied often. The PA must have a complete understanding of the procedure to be performed, including the indications and contraindications, a command of the anatomy involved, an attention to detail, and an awareness of the goal that is to be accomplished by each procedure.
A majority of all clinical procedures are painful in some way to the patient. Many times, the patient’s ability to cope with a procedure lies in the sure hands of the clinician. A positive, gentle manner combined with thoroughness in the explanation will instill confidence in the patient, as well as in the other health care providers assisting with the procedure. A patient who has a complete understanding of what is to be accomplished is much more likely to cooperate with specific requests and is better prepared to handle any difficulties that may be encountered. Finally, no matter how many times a PA student or PA may have performed a clinical procedure, he or she must keep in mind that it may be the first time for the patient and that the better prepared the patient is, the more satisfying the outcome will be.
Wounds and their Treatment
Any consideration of an invasive clinical procedure must begin with an understanding of wounds and their healing process. This chapter provides only a brief overview of wounds because a detailed explanation of the pathophysiology is beyond the scope of this discussion. The resource list at the end of the chapter provides sources for more comprehensive study and an in-depth discussion of specific types of wounds.
Definitions
A wound can be defined as any break in the normal anatomical relationship of tissues. Wounds can be classified as internal (those inside the skin) and external (those involving the skin). This chapter concentrates on external wounds because of their relationship to the performance of clinical procedures.
Wounds caused by any clinical or surgical procedure are classified, according to degree of contamination and risk for infection, as clean, clean-contaminated, contaminated, or dirty, as follows:
- •
Clean: A clean wound is typically a surgical incision made under sterile conditions. Clean wounds are generally considered to be relatively new wounds, meaning that they are less than 12 hours old. For the most part, wounds caused by clinical procedures are performed under sterile conditions and therefore can be considered clean.
- •
Clean-contaminated: A wound that begins as a clean wound but has experienced a potential source of contamination is clean-contaminated. One example is the opening of the colon during a bowel anastomosis. In this case, special precautions should be initiated to prevent spillage.
- •
Contaminated: A contaminated wound may have begun as a clean wound or may have been made under nonsterile conditions and has a greater incidence of infection. Some examples are a knife or glass laceration; the bowel opened during an operation with spillage of the contents into the surrounding sterile tissue; and the opening of an abscess, whether accidentally or by design, without containment of the enclosed infected material.
- •
Dirty: A dirty wound presents with an established infection—for example, a soft tissue abscess.
Wound Healing
Wounds heal by forming scars. The process of forming scars is traditionally divided into three main phases:
- 1.
Inflammatory phase, including hemostatic factors
- 2.
Proliferative phase
- 3.
Maturation phase
Inflammatory Phase
Wound healing begins immediately after an injury has occurred to otherwise normal tissue. The inflammatory phase, which usually lasts for 2 to 4 days, serves to cleanse the wound of dead tissue and foreign objects by a sequence of physiologic and biochemical events, beginning with an immediate vasoconstriction to minimize blood loss. This vasoconstriction is brief and is followed by a histamine-induced vasodilatation and a migrating of leukocytes into the wound. The polymorphonuclear neutrophils (PMNs) and mononuclear leukocytes are the source for many of these mediators of the inflammatory response. The primary role of the PMNs and monocytes is to debride the wound of any foreign material. Serum enters the wound from gaps between endothelial cells, aiding the activation of platelets, kinin, complement, and prostaglandin components of the clotting cascade.
Hemostatic Factors
The hemostatic factors of wound healing are all activated immediately after the injury. One of the first is the activation of platelets, which adhere to one another and to the edges of the wound, forming a plug that attempts to cover the wound. This plug or clot soon retracts and stops the loss of blood. The kinins are a group of polypeptides that influence smooth muscle contraction, which may induce hypotension. Additionally, they increase the permeability of small blood capillaries, serving to increase the amount of blood flow, which in turn increases the amounts of other hemostatic factors previously mentioned.
Complements are other hemostatic factors whose main job is to produce bacteriolysis and hemolysis by accumulating fluid within the cells, causing them to eventually rupture. Prostaglandin acts to increase vasomotor tone, capillary permeability, smooth muscle tone, and the aggregation of platelets. Fibronectin aids in the migration of neutrophils, monocytes, fibroblasts, and endothelial cells into the wound and promotes the ability of these cells to adhere to one another, creating a framework of fibrin fibers. Fibronectin is found in abundance within the first 48 hours, gradually decreasing as protein synthesis begins to produce the collagen fibers that will eventually be the scar. The wound appears red and swollen and is painful and warm to the touch during the inflammatory phase, which typically lasts about 4 days. Accordingly, it is difficult to distinguish from an early wound infection at this time.
Fibroblastic or Proliferative Phase
The second phase of wound healing can begin only when the wound is covered by epithelium. This phase begins on or about the fourth day after an injury and continues alongside the maturation phase. An injured patient must have a normal amount of circulating calcium (Ca), platelets, and tissue factor before the second phase can begin. If these three substances are present as blood is exposed to air, prothrombin will be converted to thrombin. Thrombin acts as a catalyst in the conversion of fibrinogen to fibrin fibers, which stabilize the clot.
Fibroblasts are normally located in the perivascular tissue, and when they get into the wound, they produce several substances essential to wound repair, ending with the formation of collagen fibers. Collagen is the principal structural protein found in tendons, ligaments, and fasciae. Arranged in bundles, it strengthens and supports these tissues. Collagen levels rise continuously for approximately 3 weeks and have a negative feedback mechanism related to the number of fibroblasts found in the wound. As collagen increases, the number of fibroblasts decreases, eventually causing a decrease in the production of collagen. The rapid gain in tensile strength during this phase is directly related to the remodeling of collagen from a randomly arranged fiber mesh to a more organized formation of fibers that respond to the local stress found at the wound site.
At this stage, although it is less swollen, inflamed, and painful, the wound may look its worst. The scar may appear beefy red and may feel hard and raised. This is normal and should be expected. If the wound remains painful and inflamed at this stage of the healing process, however, some foreign material may have been retained, and reexploration may be warranted.
Maturation Phase
During this third phase of wound healing, metabolic activity remains high, but there is no increase in collagen production. This phase is sometimes referred to as the “remodeling phase” because of the rearrangement of the collagen fibers from their initial haphazard appearance after production to one of more organization. This pattern is determined by the anatomical location of the wound and the amount of stress placed on the skin and the scar at that location.
This phase usually begins at 3 weeks and can be active for 9 to 12 months, depending on the health status of the person. The appearance of the scar becomes less conspicuous as it begins to flatten out and fade and gradually begins to resemble normal skin tissue. The scar becomes more supple and more permanent as the cross-links of collagen are reorganized.
Factors That Affect Wound Healing
The health of an individual can greatly affect the time involved in the healing of a wound. Proper wound closure is paramount to the successful healing of an injury, but many other factors influence this process. The surgical technique, the type of injury, the degree of contamination, and the health status and biochemical makeup of the patient all play important roles in the final outcome of an injury. Suturing and other techniques of wound closure are discussed later in the chapter, but first, some consideration of the biochemical factors and the health status of an individual with a wound are warranted. Some of the factors that directly relate to the healing process are as follows:
- •
Oxygen: Fibroblasts are closely related to the partial pressure of oxygen (P o 2 ) in the circulating blood. A P o 2 of less than 30 mm Hg severely retards the healing process by lowering the production of collagen in the cytoplasm of the fibroblast. Disease processes such as small vessel atherosclerosis, chronic infection, and diabetes mellitus can be greatly affected by the oxygen delivery system.
- •
Hematocrit: There must be an adequate supply of hemoglobin in the blood to carry oxygen to the tissues.
- •
Steroids (antiinflammatory): Steroids slow the inflammatory phase of the healing process by inhibiting macrophages and fibrogenesis.
- •
Vitamin C: Vitamin C is important to the maturation process of fibroblasts.
- •
Vitamin E: In large doses, vitamin E can decrease the tensile strength of a wound by lowering the accumulation of collagen.
- •
Zinc: Epithelial and fibroblastic proliferation is slowed in patients exhibiting a low serum zinc level.
- •
Antiinflammatory agents: Aspirin and ibuprofen decrease collagen synthesis in a dose-related fashion.
- •
Age: Both tensile strength and wound closure rates decrease as a person ages.
- •
Mechanical stress: Wounds involving the skin over joints, where the stresses are greatly increased by normal usage, take longer to heal. The delay is caused by the constant stretching and tearing of the collagen mesh, which results in reinitiating the entire wound-healing process.
- •
Nutrition: Poor nutrition results in absence of the essential building blocks of protein for collagen production, prolonging the inflammatory phase and inhibiting fibroblasia. Glucose supplies energy for leukocytes to function. Fats are necessary for synthesis of new cells.
- •
Hydration: A well-hydrated wound, not a wet wound, epithelializes faster than a dry wound. Keeping a wound covered by a dressing enhances the humidity of the wound and speeds the healing process.
- •
Environmental temperature: Wound healing time is shortened by environmental temperatures greater than 30°C. Wound healing time can decrease as much as 20% in temperatures of 12°C or less, owing to vasoconstriction and lowering of the capillary blood supply.
- •
Denervation: Denervated skin is less susceptible to local temperatures and more prone to ulceration. Patients with paraplegia develop massive, rapidly destructive ulcers that can be five times worse than those in patients with intact nervous systems.
- •
Infection: The ability of local tissue defenses to cleanse the wound is greatly diminished by a larger number of pathogenic organisms. Infection prolongs the inflammatory phase of the healing process.
- •
Idiopathic manipulation: Overhandling and rough handling of tissue by health care providers along with tight sutures can result in tissue ischemia and poor healing.
- •
Chemotherapy: Anticancer drugs decrease the fibroblast proliferation.
- •
Radiation therapy: Acute radiation injury is manifested by stasis and occlusion of small vessels, resulting in the formation of ulcers at the point of ischemia.
- •
Diabetes mellitus: Defective leukocyte function and microvascular occlusion may occur secondary to hyperglycemia in diabetes mellitus. High glucose levels interfere with the ability of cells to transport ascorbic acid, resulting in a decrease in the production of collagen.
Wound Anesthesia
Anesthesia is used in a number of different ways. The most common is local, whereby just the area around the wound is anesthetized. A hematoma block is local anesthetic injected directly into a hematoma. This is primarily used in fractures in which there is some internal bleeding around the fracture site. The anesthetic is allowed to filter throughout the surrounding tissue and fracture site. When an adequate amount of anesthesia has been achieved, the fracture can be set. A field block is the injection of an anesthetic around a given surgical operative site. A nerve block targets a specific nerve at a distant site from the area of the proposed surgery. A digital block administered at the base of the involved finger or toe is used to numb an entire digit. This is especially useful when a laceration of a finger or toe is massive and a local infiltration would result in increased swelling and a more difficult closure. Injection of the anesthetic on both sides of the affected digit will provide effective anesthesia to the area. Last, a regional block is used to anesthetize a large specific area; for instance, an epidural block (regional) allows the parturient patient to remain awake during the delivery of her child. A digital block may be referred to as a regional block in some instances. Regional blocks may affect the motor activity of the affected area.
The properties of the ideal local anesthetic are few and simple. It must be easy to administer and have a rapid onset. Its effect must last as long as needed for a given procedure, and it must dissolve completely, with no adverse effects or toxic effects either locally or systemically. Local anesthetics work by blocking depolarization of a nerve impulse. Of the numerous anesthetic agents available on the market today, lidocaine is probably the most widely used for local anesthesia. It is manufactured in a variety of solutions, but the two most commonly used for local anesthesia are 1% and 2%. One percent lidocaine works well in blocking pain stimuli while leaving the sensations of touch and pressure relatively intact. Two percent lidocaine usually blocks all stimuli from a wound area.
Two other agents, procaine hydrochloride (Novocain) and bupivacaine hydrochloride (Marcaine), are well known and warrant some discussion. Novocain has a rapid onset, usually about 4 to 7 minutes, and lasts approximately 1 hour. Lidocaine has an equally rapid onset but may last approximately 3 hours. Marcaine takes longer to reach its anesthetic level but lasts up to 10 hours. Choosing the right anesthetic for the wound takes a significant amount of skill that is developed with years of wound evaluation and experience. The clinician must also be aware of the possible complications involved in the use of these agents. Some general rules to avoid any complications are of value, and the safety of the patient should always be of primary concern, as with the use of any medication.
Use the least amount of local anesthetic to gain the maximum amount of anesthesia for a given wound.
Almost all the local anesthetic agents give the patient a sensation of burning on injection. Before injecting, explain to the patient that this is a normal response. When injecting, go slow and wait for some of the anesthetic effects of the agent to begin working before continuing.
Always aspirate when attempting to inject an agent into the body. If there is a blood return, remove the needle and apply local pressure to ensure hemostasis.
Be aware of the signs of an allergic reaction, such as wheezing, hives, and hypotension. Always be prepared to support the airway with ventilations if necessary. Although a true allergic reaction to lidocaine is rare, extra precautions should be taken if the patient reports any history of this type of allergy.
Be aware of the maximum dosages allowable for local anesthetic medications. The toxic dose of plain lidocaine is 7 mg/kg when it is administered over 1 hour. The common side effects that are associated with lidocaine toxicity include blurred vision, tinnitus, and tremors. Cardiac side effects can also occur, including heart block and a decrease in cardiac output.
The last area for potential complications concerns local anesthetics that contain a vasoconstrictive agent. Epinephrine, in concentrations of 1:100,000 or 1:200,000, is most commonly used to prolong the effects of the local anesthetic. Because of its vasoconstrictive action, it may also be used to control or decrease bleeding. It is this use for which the potential for complications arises. The local anesthetics that contain epinephrine should never be used in areas of the body that have terminal vasculature, such as the ears, tip of the nose, fingers, penis, and toes. The vasoconstricting action can lead to tissue death and gangrene in such areas. There is also a higher potential for wound infection because prolonged vasoconstriction delays the highly effective cleansing agents from entering the wound. Adherence to meticulous hemostasis is also important under these conditions to control the potential for increased bleeding after the effects of epinephrine wear off.
The anesthetics mentioned in this discussion are easy to use and readily available. The resource list at the end of this chapter provides in-depth studies of these agents.
Sutures
Numerous types and sizes of suture materials are available. A variety of different sutures may be used to adequately repair any given wound. The selection of suture material depends on the type of wound (clean vs. contaminated), the location of the wound (face vs. arm or leg), and the personal preference of the clinician. The following discussion provides some general principles to help in the selection of a dependable suture for a specific area of the body and a specific type of wound.
Suture Types
Sutures can be divided into two categories, absorbable and nonabsorbable. Absorbable sutures may be either natural (e.g., plain catgut, chromic catgut) or synthetic (e.g., polyglycolic acid [Vicryl or Dexon], polydioxanone [PDS]). Nonabsorbable sutures may be either multifilament (e.g., silk, cotton) or monofilament (e.g., nylon, polypropylene [Prolene], stainless steel wire).
When evaluating a wound for primary closure, the clinician must keep in mind the ideal qualities of a suture and must choose the most appropriate suture for each particular wound. The ideal suture:
- •
Maintains adequate tensile strength until its purpose is served
- •
Causes minimal tissue reaction
- •
Does not serve as a nidus for infection
- •
Is nonallergenic
- •
Is easy to handle and tie
- •
Holds knots well
- •
Is inexpensive
- •
Is easily sterilized
Absorbable sutures should be used when the suture needs to function for a short time and cannot be recovered when its use is completed, as for the inner layer of a bowel anastomosis. The suture serves only to approximate the mucosa and to assist in temporary hemostasis until the body’s hemostatic mechanism can secure permanent hemostasis and wound closure. The suture used most often for this type of anastomosis is catgut. Absorbable catgut sutures, which are obtained from the small intestine of cattle or sheep, generate an inflammatory response within the wound that eventually leads to their absorption. Plain catgut sutures lose approximately 50% of their initial tensile strength in just 7 days. Chromic tanning of plain catgut (chromic catgut), on the other hand, prolongs the absorptive time and the life of this suture to about 3 weeks. The synthetic absorbable sutures (Vicryl, Dexon) do not generate as extensive an inflammatory response as catgut suture material. Their chief advantage is their uniform loss of tensile strength. Research has shown that these sutures lose their strength at a steady rate for about 21 days, at which time they have no residual benefit.
Silk, throughout the years, has been the most commonly used nonabsorbable suture. It is easily obtained at a lower cost than the monofilaments and is comfortable to work with. Additionally, it holds knots securely. The major disadvantages of using silk include the following:
- 1.
The tissue reaction it stimulates, which, although less than that produced by catgut sutures, is more than that of the synthetic monofilaments
- 2.
It is a multifilament suture that may be associated with an increased risk for inflammation.
A multifilament suture is made of many filaments or fibers intertwined, producing numerous interstices (spaces between the fibers) that, when contaminated with bacteria, serve as a continuous nidus for infection. The interstices are small enough to deter body host defenses but large enough for bacteria to multiply. Cotton suture has the same advantages and disadvantages as silk; however, cotton is slightly weaker than silk initially but maintains its tensile strength in the tissue for a longer period.
Monofilament sutures (nylon, polypropylene [Prolene], poliglecaprone [Monocryl] stainless steel wire) share the advantages of prolonged high tensile strength, low tissue reaction, and lack of interstices. Their chief disadvantages are difficulties for the clinician in handling and tying knots. More throws (seven or eight) are required in a single knot to maintain its security. The monofilaments are also more expensive and are less readily available than silk and cotton.
Suture Sizes
Suture sizes are graded by a number or a zero (e.g., 2, 1, 0, 00 [2-0], 000 [3-0], 0000 [4-0], 00000 [5-0], and so forth); the more zeros, the smaller the diameter of the suture material. Whereas the larger sizes (2, 1) are used for heavier work (i.e., closing fascia layers or placing retention sutures in the abdomen), the smallest sutures (9-0 or 10-0 and smaller) are used exclusively in microvascular surgery.
Choice of Suture
The question remains: What type of suture should be used? Because of the numerous types and sizes of sutures available to the clinician, the choice of sutures for each specific purpose reverts to personal preference and wound closure experience. Because many possible different sutures can be used to close a wound, Table 14.1 is supplied as a general guide for novices in choosing the type of suture according to the anatomical location of the wound.
| Location of Wound | Suture Size | Suture Type |
|---|---|---|
| Skin | ||
| Face | 5-0, 6-0 | Nylon |
| Hands | 4-0, 5-0 | Nylon |
| Scalp | 3-0, 4-0 | Nylon |
| Extremities, abdomen | 3-0, 4-0 | Nylon |
| Subcutaneous tissue | 3-0, 4-0 | Vicryl, Dexon |
| Fascia | 0 | Prolene |
| 2-0 | Stainless steel wire | |
| 0 | Surgilon | |
| Peritoneum ∗ | 2-0, 3-0 | Vicryl, Dexon |
| Bowel anastomosis | ||
| Inner layer | 3-0, 4-0 | Catgut |
| Outer layer | 3-0, 4-0 | Silk, propylene |
Suture Needles
Two basic types of needles are used with suture material in surgery, tapered and cutting ( Fig. 14.1 ). A tapered needle has a sharp point and a round body. Tapered needles are less traumatic to the tissues than cutting needles. Cutting needles are beveled and have sharp, knifelike edges that make them well suited for skin sutures. A general rule is that cutting needles are used for skin suturing, and tapered needles are used for most other tissues.
Sutures come prepackaged with a label indicating the size, type, and length of the suture and the type and size of the suture needle. Labels are usually color coded according to the type of suture material contained.
Skin sutures should be removed when they have fulfilled their purpose. The longer sutures remain, the more inflammatory the response they generate, which ultimately results in a larger, more noticeable scar. The clinician must weigh the odds of creating an unsightly scar against the chance of a wound dehiscence if the sutures are removed prematurely. The following is a guideline for when to remove sutures according to location:
Face: 3 to 4 days
Scalp: 5 to 7 days
Trunk: 6 to 8 days
Extremities: 7 to 14 days; longer for areas under maximal tension
Wound Closure
Wounds, however they are created, require proper and timely attention to facilitate the best possible outcome. A few general principles can aid in deciding on the best approach for wound closure. Determining the cause of the wound and the possibility of contamination is important. Surgical wounds are almost always closed primarily because of the controlled atmosphere in which they are created. Acute, accidental wounds need much more evaluation before treatment. Often the decision focuses on the size and shape of a wound and the degree of contamination suspected.
Historically, there are three methods of treating wounds, and timing is the most critical aspect to consider when choosing among them.
Primary Closure
The immediate suturing, stapling, or taping of a wound yields the best possible outcome with minimal scarring ( Fig. 14.2 ). Two factors to consider in deciding whether a wound can be closed primarily are the amount of tissue loss and the degree of contamination. Clean surgical wounds fall into this category, as well as lacerations from sharp objects, such as a glass, knife, or sharp piece of metal, in which there is almost no tissue loss and contamination is minimal. Generally, an accidental wound is not closed primarily if it is more than 8 hours old. In instances in which the wounds are in areas with a good vascular supply (i.e., the face and scalp), wounds can still be closed if more than 8 hours old, although each patient needs to be evaluated on an individual basis to determine whether it is appropriate to close primarily.
Delayed Primary Closure
The wound is left open, usually because of a significant amount of bacterial contamination. Through a process that is not fully understood, the wound develops a resistance to infection over the next 4 to 5 days ( Fig. 14.3 ). This development occurs only if the wound is cleansed of all foreign material and is loosely packed with a sterile dressing. The wound is then closed by approximation of the two sides using as little suture as possible.
Healing by Secondary Intention
A wound treated by secondary intention typically involves a large amount of tissue loss or heavy contamination by bacteria. In this case, the wound closes by the process of epithelialization and contraction rather than any type of suturing ( Fig. 14.4 ). The wound is carefully observed throughout the healing process, which may take weeks or months. To promote healing, the wounds are packed with sterile dressings that are changed daily to promote debridement of the wound. All wounds heal in this manner if they can remain free of bacteria and no fistula or sinus tract develops. The cosmetic result of this type of closure is extremely poor, however, and may require consultation with a plastic surgeon to improve the cosmetic result.
Wound Suture
The principles of wound suturing are few and simple. Ideally, when the clinician is evaluating a wound for primary closure, he or she wants to produce the best possible result with the least amount of pain by using the most appropriate material with the least financial cost to the patient. A person’s skin is his or her showcase to the world, and wounds and scars create physical changes that often affect self-image. The psychological aftermath of scars can be deeper than the wound itself. Every health care provider must be aware of how an injury has affected the patient. Clinicians can maximize cosmetic results by perfecting their techniques as much as possible. A referral to a plastic surgeon is appropriate for more complicated wounds, especially those involving the face and hands.
Two things make scars visible, color and shadows. The clinician has little control over the color of the patient’s skin, but the smaller the scar, the less likely it is that a color change will occur. Shadows, however, are created by a centralized light source catching a subject at an angle. Even the smallest elevation or indentation of a scar makes it visible ( Fig. 14.5 ). The only way for the clinician to address this concern is to make the scar as flat as possible because a flat scar leaves no shadow.
First Principle
The first principle of wound repair is to close the wound in layers, making sure that each layer of skin, from the deep fascia to the epidermis, butts up against its counterpart on the other side. Perfect epithelium-to-epithelium matching and a technique called “everting of the skin edges” give the best possible result ( Fig. 14.6 ). The key is to remove tension from the outer wound edges by placing absorbable sutures inside deep lacerations and matching them layer to layer. This arrangement supports the skin and removes any underlying abnormal pull on the skin. Correctly placed layered stitches can result in a closure that may not even need skin sutures. The skin edges are everted by making sure that (1) the depth of the stitch is greater than the width and (2) the stitch reaches the bottom of the wound.
Adherence to this principle automatically everts the skin edges ( Fig. 14.7 ). As the suture needle is placed in the skin, it should follow a direction that is oblique, back, and away from the wound edge. This creates the desired bottleneck effect of the stitch in the wound ( Fig. 14.8 ). In a wound that has been closed with this technique, the tissue will fall back into place when the sutures are removed, and the scar will eventually flatten.
Second Principle
The second principle of wound repair is to match any landmarks that are readily identifiable. Before the first stitch is placed, the wound should be inspected for the location and identification of landmarks (e.g., creases or wrinkles, birthmarks, old age spots, tan lines, hairlines, the vermilion of the lip, eyebrows, eyelids, tattoos). The first stitch should be placed in the landmark or as close to it as possible to match it precisely. Stair-step effects in linear lines, especially on the face, are visible, and extreme caution should be taken to avoid this result.
Third Principle
The third principle is the need for proper placement of the sutures. In the majority of the lacerations seen in emergency departments (EDs), one side of the wound is longer than the other. Care must be taken in attempting to correct this imbalance. Taking more tissue between stitches on one side than on the other will create what is known as a “dog ear.” To avoid a dog-ear effect, it is essential to place the sutures at the same distance along each side of the wound. In the absence of landmarks, measuring may be necessary. A good rule to follow is to measure ¼ inch down one side of the laceration from the apex, place the stitch in the skin about ¼ inch from the wound edge ( Fig. 14.9 ), and then repeat the procedure on the other side. This method gives the most accurate closure possible.
Wound Tension
Wound tension is another aspect of suturing that must always be considered. The amount of tissue captured within a suture loop, no matter how little, creates a potential for ischemia by the overzealous use of force when the knot is tightened. The reduced capillary blood flow within the suture loop can result in tissue necrosis, prolonging the inflammatory response and potentially leading to a breakdown in healing that can result in a dehiscence of the wound. The wound edges should be brought together so that they merely touch because edema created by the inflammatory response increases the amount of tension in the suture loop. Approximating the edges so that dead space is eliminated and tension is minimal should be the goal in each wound closure.
Debridement
Occasionally, a wound may need debridement before primary closure. Debridement is the careful removal of dead or damaged tissue in addition to any unwarranted foreign material from the wound. This procedure should be considered when wounds, such as crush injuries, create jagged edges that have obliterated any previously existing landmarks. The goal of the clinician at this point is to create a more manageable wound that will produce a better cosmetic result and minimize the opportunity for any bacterial growth. Occasionally, the margins of a wound will be ragged and contused. The wound can be converted into a nicely incised surgical wound by excision of a 2- to 3-mm wound margin. This can be most easily accomplished by using a #15 surgical blade on a scalpel to cut into the dermis along a predetermined line that is safe to excise. Cut along the line created by the scalpel with a pair of surgical cutting scissors, excising the margins of the wound in a perpendicular fashion. After debridement of the wound, especially if the skin edges are involved, the wound may require undermining of the skin to bring the skin edges together without tension on the wound ( Fig. 14.10 ). Do not excise tissue on the scalp or the eyebrows. This will create a prominent hairless scar.
