Chapter 17: Table of Contents
Common bandages consist of three layers: the inner layer in direct contact with the skin known as the ‘Contact’ or ‘Primary’ layer, the ‘Absorbent’ or ‘Secondary’ layer and the ‘Support’ or ‘Tertiary’ layer. The contact layer is made of a sterile or non-sterile material that may be adherent (e.g. wet to dry bandage) or non-adherent (e.g. petroleum impregnated gauze). The absorbent layer is often a material such as bulk cotton or thinner cast padding. Often the absorbent layer may be surrounded by a non-elastic conforming gauze material which holds the absorbent material in place. Lastly, the supporting layer is usually made of an elastic wrap to provide a secure fit for the bandage and maintain an internally clean environment. Common bandaging techniques are further described.
BANDAGE TYPES:
- Light Pressure: The light pressure bandage is often used to cover wounds or minimize swelling of injured limbs. It is very important to bandage the limb in its normal functional position to allow proper use of the limb and for comfort of the animal.
- Light Pressure Application: The light pressure bandage is often used to cover wounds or minimize swelling of injured limbs. The animal is placed in lateral recumbency and the limb is held in position to prevent hyperextending or hyperflexing during bandaging. It is very important to bandage the limb in its normal functional position for patient comfort and to allow proper use of the limb.
- Applying stirrups: Two stirrups, each approximately 20 cm long, made with non-elastic tape are placed opposite one another either on the lateral and medial surface or dorsal and palmar/plantar surface of the foot. They are placed with half of their length over the distal limb while extending the other half beyond the end of the limb. The free ends of tape are temporarily stuck to one another.
- With an assistant: Bandaging is much easier with an assistant holding the limb. If possible, the assistant should hold the toes rather than the stirrups.
- Applying the contact layer: If a wound (surgical or other) is present on the limb, it is first covered with an adherent or non-adherent dressing prior to applying the bandage. This dressing represents the contact or primary layer of the bandage.
- Applying the absorbent layer: The secondary layer is usually made of cotton and is wrapped around the contact layer overlapping by 50% as you wrap up and down the limb.
- Applying conforming gauze: After applying the desired amount of absorbent/padding material, conforming gauze is used to provide mild pressure and conform the material to the limb. The gauze roll is wrapped up the limb (and back down if required) overlapping by 50% while providing constant mild tension. It is important to create equal tension along the entire limb preventing high pressure areas as this might impair vascular and lymphatic flow potentially leading to serious swelling of the toes and distal limb.
- Adhering the stirrups: Next, the stirrups are separated and applied vertically (with the adherent side towards the bandage) to hold the bandage in place.
- Robert Jones: Robert Jones bandages are usually used to decrease soft tissue swelling and stabilize fractured limbs before surgical repair.
- Robert Jones Application: Stirrups are applied as in the light pressure bandage but they should be about 5cm longer. With the patient in lateral recumbency, the limb is held in a weight bearing position. If a wound is present on the limb, an adherent or non-adherent cover is placed as a contact layer over the wound. Cotton padding is then applied directly to the limb overlapping by 50% as it is wrapped from the distal to proximal region. Since this bandage is used to stabilize fractures and absorb large amounts of exudate, it must be very well padded, requiring two to three layers of bulk cotton. Conforming gauze is then applied and wrapped distal to proximal with as much tension as possible. Two layers are frequently required to create enough tension while creating a uniform diameter along the entire bandage length. Enough cotton padding must be applied prior to tightening the gauze roll to prevent compromising circulation to the limb. Lastly, apply a support bandage of elastic wrap (distal to proximal) overlapping by 50%. The completed bandage should sound like a ripe melon when flicked by the finger.
Incorrect Bandaging: A bandage that is applied too tightly or tightens because it becomes wet or moves after application can have devastating consequences. For this reason, the third and fourth digits should be visible to allow twice daily examination for evidence of swelling, divergence of the toes, coldness, pain or discharge. If any of these signs are noted, the bandage should be removed as soon as possible (and potentially replaced) to prevent limb ischemia.
SPLINTS
Splints: For additional support, a splint may be added between the absorbent and support layers, commonly on the caudal aspect of the forelimb or on the lateral aspect of the hindlimb.
- Applying the support layer: After folding over the stirrups, a support or tertiary layer is applied to provide support and protect the internal layers from contamination. This usually consists of an elastic wrap or tape that is once again overlapped by 50% as it is wrapped up the limb. Application of this layer is typically done under relative tension in order to provide support. However, excessive tension must be avoided as this may prevent normal lymphatic drainage leading to distal limb swelling.
- Examining the toes: All layers making up the light pressure bandage should begin at the distal end of the limb without completely covering the toes allowing examination. The third and fourth digits should be visible and are typically examined twice daily for evidence of swelling, divergence of the toes, coldness, pain or discharge suggesting that the bandage might be too tight. If any of these signs are noted, the bandage should be removed as soon as possible (and potentially replaced) to prevent limb ischemia.
SPLINT TYPES:
- Fiberglass Spica: Splints are frequently included in bandages to provide further support to fracture and tendon repairs. Splints can be made of various materials. A simple, economical and strong splint can be made to measure for the patient using a multi-layered strip of fiberglass casting material. Splints can be applied to any area of the limb to span a portion of the distal limb only and sometimes the entire limb. Most splints are applied on the lateral or the caudal surface of limbs. Spica splints are lateral splints that cover the entire length of the front limb and cross over the chest and dorsum to the level of the contra-lateral shoulder. These splints are used to immobilize the entire limb (including the shoulder and elbow).
- Spica Application: First, a soft padded bandage (with stirrups) is applied to the limb. This bandage can be continued on the proximal portion of the limb and around the chest using cast padding in small patients. Another option is to use a sheet of bulk cotton to extend the padded area over the upper limb, shoulder, and dorsum to the level of the contra-lateral shoulder. Conforming gauze is then placed on the distal limb bandage and is continued around the thorax to hold the cotton in place. Ensure that adequate tension is placed to prevent motion of the bandage material under the splint but that the thoracic cavity is not excessively compressed as this may result in respiratory difficulties (this is especially easy to do in anesthetized patients due to muscle relaxation). The previously placed stirrups are then folded over to prevent the bandage slipping. Another option is to fold one or both stirrups over the splint and bandage at a later stage; this will prevent motion of the splint in the bandage and is especially useful when shorter splints are applied. Water activated resin (fiberglass) casting material is used to create the spica splint. Gloves should be worn while handling this material to prevent the resin sticking to your hands. Fiberglass casting material is available in various widths; choose the appropriate width for the desired splint and size of the patient. The desired splint (length and thickness) is created prior to immersing the casting material in water; water will activate resin polymerization (hardening) limiting the time available to create the splint. Multiple layers (usually 6) of the casting material are used to create a strong splint. Pre-measure the required length on the patient to ensure that a splint of adequate length is created. The multiple layers of casting material are joined with pressure and the material is immersed in water to fully activate the resin. Excess water is stripped from the material to prevent excessive wetting of the bandage. The splint (while still soft) is then placed and conformed to the lateral aspect of the dog’s limb and over the shoulder and back towards the opposite shoulder. While the splint is still soft, a ridge may be formed along the length of the casting material to improve bending rigidity. The resin will harden in 5-10 minutes via polymerization of the resin; heat is produced during this process. It is sometimes helpful to place one layer of conforming gauze over the splint during polymerization (hardening) to ensure that the splint conforms well to the limb and bandage (not shown in the video clips); this gauze usually becomes wet and should be replaced after polymerization is complete. Once the splint is polymerized, it should be incorporated in the bandage using conforming gauze starting at the dog’s foot towards and around the thorax. Tape strips (or the stirrups if these were not reflected onto the bandage earlier) can be used to stabilize shorter splints within the bandage (not shown in the video clips); ensure however, that a 360 degree tape strip is not placed as this could create pressure and lead to swelling of the limb distal to the tape strip. Non-adherent elastic material is then applied to complete the tertiary layer of the splint. This type of splint could also be applied to the hind limb of female dogs to decrease motion in the hip joint and proximal femur.
SLING TYPES:
- Ehmer Sling: The Ehmer sling is used to prevent weight bearing and promote reduction of the femoral head in the acetabulum after closed or internal fixation of coxofemoral luxations.
- Ehmer Application: The Ehmer sling is used to prevent weight bearing and promote reduction of the femoral head in the acetabulum after closed or internal fixation of coxofemoral luxations. Next pass the tape over the top along the lateral aspect of the thigh, pulling the skin distally to prevent slipping, and direct it caudal to the stifle, medial to the hock and ventral to the metatarsus with the adhesive side still against the skin. Repeat the same pattern several times to provide adequate support. To complete the bandage the tape may be cut and adhered to the existing bandage (allowing the limb to adduct) or if it is desired to abduct the limb, the bandage may be ended by pulling the tape over the back of the animal towards the opposite limb and around the abdomen (cannot be performed in male dogs). It is important to remember that the Ehmer bandage applies significant pressure over the quadriceps muscles and thus monitoring for muscle damage is important. The toes and tibia should also be checked for swelling periodically.
CASTS
- Cast Application: Casts may be applied as a form of external fixation for simple fractures located distal to the elbow or stifle only. It is important to remember that a cast must extend beyond the fracture line by at least one joint above and below and must never end in the middle of a long bone. Casts should always be applied with the patient under general anesthesia. First, stirrups are applied as in the light pressure bandage. A stockinette is prepared by rolling it into a doughnut configuration for ease of application to the limb. The stockinette is applied to the limb by unrolling it distal to proximal. (It can be attached proximally with a towel clamp if necessary). After reduction of the fracture, the limb is held (by an assistant) in a normal weight bearing position to allow walking on the limb after cast application. Cushioning may be added to certain pressure points on the limb, such as over joints or bony prominences using cotton padding. The cast material (plaster of Paris or fiberglass) is then applied overlapping it by 50 percent as the limb is wrapped distal to proximal and vice versa. If using plaster of Paris, the layers are smoothed as they are placed to prevent any pressure points from forming or from development of weak points in the cast. Fiberglass casts tend to apply more uniformly. Two layers of cast material are often applied. After applying the cast material, excess stockinette ends are trimmed leaving 3-5cm to be folded over the cast ends. Next, the stirrups are separated and applied to the cast vertically. The stirrups and stockinette are covered with precut pieces of cast material at the proximal and distal ends of the cast. It is important to support the cast while hardening occurs to prevent formation of pressure points or cast weakness. If any defects in the cast occur removal will be required. Plaster of Paris casts will take longer to set than fiberglass casts
- Fiberglass Cast: Fiberglass cast application is similar to that of Plaster of Paris except that the fiberglass material sets within minutes requiring rapid and accurate application. Descriptive steps for Fiberglass cast application are being developed.