To adequately evaluate a wound, hemostasis is needed to prepare a clear visual field. The most common sources of wound-related bleeding are the subdermal plexus and superficial veins. Oozing from these sources can usually be controlled with the application of direct pressure using saline-soaked sponges or gauze.
In the event of continual bleeding, the next step is typically an attempt at chemical hemostasis using epinephrine mixed with local anesthetics in concentrations of 1:100,000 or 1:200,000 and injected into the wound area. Local epinephrine induces vasoconstriction that will additionally allow a longer duration of anesthesia and a larger total local anesthetic dose due to the depot effect of the vasoconstriction.42,43,44,45 Despite the theoretical risk of end-organ ischemia (i.e., fingers, nose, ears, toes), when mixed with local anesthetics, the safety of epinephrine use in these regions has been well documented.46, 47, 48, 49, 50, 51, 52 Use caution in patients with small vessel disease, where end-organ epinephrine injection remains ill advised. Although epinephrine interferes with wound healing in experimental animal models,4,5 no increase in wound infection has been observed with the addition of epinephrine to local anesthetics used in the ED.
Physical means of applying pressure to bleeding include the use of gelatin, cellulose, or collagen sponges placed directly into the wound. Denatured gelatin (Gelfoam®; Pfizer, Inc., New York, NY) has no intrinsic hemostatic properties and works by the pressure it exerts as it expands. A cellulose derivative (Oxycel®; Becton Dickinson Infusion Therapy Systems, Inc., Sandy, UT) or a collagen (Actifoam®; MedChem Products, Inc., Woburn, MA) sponge reacts with blood, forming an artificial clot. These products are not particularly effective for actively bleeding wounds, as the blood flowing into the wound can wash them out.
If the source of bleeding is a small vessel that has been lacerated but can be easily visualized, control may be achieved through direct pressure applied with a gloved fingertip directly on the vessel. Once bleeding has ceased, more permanent control can be obtained by clamping the vessel, isolating a short length, and ligating it with absorbable synthetic suture (typically 5-0). Take care to avoid clamping or ensnaring adjacent structures (i.e., nerves and tendons), particularly when working with wounds of the face.
For bleeding wound edges where the involved vessel is not visible, a figure-of-eight or horizontal mattress suture (Figure 40-1) applied adjacent to the site of bleeding will sometimes achieve control. However, this technique may impair blood flow and leave nonviable tissue in the wound.
Suture to control bleeding wound edges where the involved vessel is not visible. Left column: Standard horizontal mattress suture. Right column: Figure-of-eight suture. [Image used with permission of Nicholas Hatch, MD.]
Bipolar electrocautery can achieve hemostasis in blood vessels <2 mm in diameter, but if improperly or too extensively applied, it can result in tissue necrosis. Electrocautery units are not routinely available in many EDs. Battery-powered, hand-held cautery devices (Figure 40-2), although more accessible, do not generate sufficient heat to produce coagulation in vessels larger than capillaries. Low-temperature units, identified where the wire loop does not glow when heated, are recommended for ED use.
Battery-powered, hand-held thermal cautery units commonly used in the ED. Top: High-temperature unit (1200°C); wire loop glows when heated. Bottom: Low-temperature unit (690°C); wire loop does not glow when heated. [Image used with permission of J. Stephan Stapczynski, MD.]
Scalp lacerations can bleed extensively from the wound edges due to the highly vascular subcutaneous layer. If traditional methods of hemostasis fail, scalp bleeding can be controlled by the use of specially designed clips applied along the wound edges (Figure 40-3). If the source of bleeding is determined to be a major artery, do not ligate the vessel. Maintain direct pressure on the vessel and obtain surgical consultation.
Raney clips are used to control bleeding from the wound edges of scalp lacerations. An applicator is used to apply the open clip. When the applicator is released, the clip closes and pinches onto the wound edges. [Image used with permission of J. Stephan Stapczynski, MD.]
Extremity wounds that are refractory to direct pressure, ligation, or cautery may require an arterial tourniquet.53 Tourniquets may compress and damage underlying blood vessels and nerves, reducing tissue viability, and therefore should not be left in place for greater than 20 to 30 minutes at a time. The simplest tourniquet to use in an ED is a blood pressure cuff placed proximal to the wound and inflated to 20 to 30 mm Hg (2.7 to 3 kPa) above the patient's systolic pressure. Elevating the extremity to reduce venous blood volume prior to cuff inflation may be useful. If an extremity tourniquet is needed to control bleeding, the best course of action is exploration and repair in the operating room.