Ring Tourniquet Syndrome

A tight ring encircling the proximal phalanx may become entrapped because of distal swelling. Such swelling may be the result of trauma, infections, skin disorders, allergic reactions, or the tight ring alone. As the digit expands, venous outflow is restricted by the tight ring, producing more swelling. This vicious cycle may lead to nerve damage, ischemia, and digital gangrene.

The finger should be assessed for lacerations, sensory function (two-point discrimination), and perfusion (color and capillary refill). Digital artery pulsations can be detected with a Doppler flow meter, although this is usually not required. The presence of impaired sensation or diminished perfusion indicates significant constriction; rapid ring removal is then warranted. Rapid removal usually requires cutting the ring. If sensation and perfusion are intact, removal can be attempted with slower techniques that preserve the ring. The exception to ring preservation methods arises when there is an underlying phalangeal fracture; it is then prudent to cut the ring off.

In all methods, the hand should be elevated to encourage venous and lymphatic drainage, thus reducing swelling. Alternatively, the finger can be circumferentially wrapped with a 1/2- to 1-in. elastic band (e.g., Penrose drain), starting from the distal tip and winding the band tightly around the finger, progressing toward the proximal phalanx to reduce swelling. The wrap is left in place for several minutes before it is unwrapped and the ring is removed by one of the methods described below. Regional anesthesia is often required, particularly in patients who cannot tolerate the pain of circumferential compression. The metacarpal block is ideal because it produces less swelling of the finger than a digital block.

The simplest technique is lubrication. A variety of water-soluble lubricants can be applied to the digit and the ring removed with circular motion and traction.

The string technique uses a length of string wound circumferentially around the finger. When string is unwrapped, the ring is advanced toward and off the distal tip of the finger. Either string, umbilical tape, or 0-gauge silk sutures can be used. Synthetic monofilament sutures should not be used because they tend to cut the skin. The required length depends on the diameter of the string and the size of the finger; up to 100 in. of string may be required. The method starts by passing one end of the string under the ring and then wrapping the finger, starting next to the ring and winding clockwise, with each loop snug against the previous one, from proximal to distal. With each loop, the tissue underneath is compressed. When it is completely wrapped, the finger should be entirely covered by the string with no tissue showing between the loops (Fig 39-M). Wrapping and compression is a painful process and usually requires regional anesthesia. To remove the ring, the proximal end of the string is slowly unwrapped in a counterclockwise manner, advancing the ring toward the distal end as the string unwinds ( Fig 39-4B). The proximal interphalangeal region is the widest portion of the finger and is the most difficult site over which to maneuver the ring. Abrasions are commonly produced with the string method.

Syndrome Tourniquet

A variety of modifications to the string technique have been described. One involves wrapping from distal to proximal so as to reduce distal edema. Elastic band compression to reduce digital edema can be combined with a blood pressure cuff inflated above systolic pressure to prevent reaccumulation of edema once the elastic band is removed.11 Another method uses a self-adherent compression bandage.12

The rubber band technique uses a 3- to 4-mm rubber band that is passed between the ring and skin; the two ends of the rubber band are then picked up by a clamp and used to place distal traction on the ring. The finger and ring are then lubricated. Traction is applied to the rubber band as it is moved circumferentially around the ring, slowly pulling it distal.13

Ring cutters are available in both manual and power models. The cutter has a small guard that fits underneath the ring and contains a channel allowing the circular blade to cut down through the ring without coming in contact with the skin. Sometimes, the swelling is so tight that the guard cannot slip under the ring. In these cases, reducing edema by using an elastic band, as noted above, may be successful. Alternatively, the circular ring may be deformed into an oval, creating a gap on the long axis of the ring. Rings should be cut in the thinnest and most accessible site. Thin and flexible rings may require only one cut; the ring is then removed by bending the two ends and pulling the ring open. Thick rings cannot easily be bent; such rings may need to be cut in two locations, opposite each other, separating the ring into two halves.

Very thick or tempered industrial objects (nuts or machine parts) may occasionally be placed on fingers and become stuck. Removal of these objects may require bolt cutters or motorized hand-held cutters. When these devices are used, the underlying skin should be protected from injury by a Silastic band or similar material. To prevent thermal burn from motorized cutters, water should be used for cooling during the cutting process.

After removal, sensation and perfusion should be reassessed. Tetanus prophylaxis may be required.

Blood Pressure Health

Blood Pressure Health

Your heart pumps blood throughout your body using a network of tubing called arteries and capillaries which return the blood back to your heart via your veins. Blood pressure is the force of the blood pushing against the walls of your arteries as your heart beats.Learn more...

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