Stockinette is a soft knit material which is in tubular form, resembles a footless stocking without seams and is available in rolls of various widths (5 to 40 cm) to cover any part of the body. It protects the skin under the plaster cast and form a lining for the cast. Stockinettes are also helpful to protect the edges of the plaster casts.
An adequate padding with cotton is necessary to protect the skin and bony prominences under the plaster cast. Padding is applied directly over the skin or over a covering of stockinette. The padding applied should be smooth and without wrinkles.
4. Warm Water
Water at the temperature of 35 to 40.5 degree celcius is necessary to saturate the plaster bandages. The setting time of plaster is also influenced by the temperature of water. Warmer temperature will speed up the setting time. When a large cast is being applied, it may be necessary to change water in between, otherwise excessive sediments of plaster accumulate and begins to adhere to the new rolls of plaster which causes slow setting of the plaster and produces lamination and weakness of the cast.
5. Special Tables (Orthopaedic Tables)
Special tables, called orthopaedic tables are used for the application of the cast. It has devices to support the uncasted area leaving the area on which the cast is applied left free.
6. Other Accessories
If a cast is to be used for bearing client’s weight during ambulation, it is fitted with a walking heel on the plantar surface. It is fitted on the plaster cast in its green stage.
TYPES OF PLASTER CASTS
1. Short Arm Cast (Wrist Plaster)
Short arm casts are applied in the treatment of the fractures of the carpel and metacarpal bones and for the dislocation of the wrist joint. It is extending from below the elbow to the phalanges. The fingers are left free to check the blood circulation and movement in the arm.
2. Long Arm Cast (Above-elbow Plaster)
This is used in the treatment of the fractures of one or both bones of the forearm and dislocation involving the elbow joint. The long arm cast extends from below the shoulder to the phalanges. The elbow joint is kept flexed.
3. Short Leg Cast (Below-knee Plaster)
This is used for the treatment of the fractures of the tarsal and metatarsal bones and for the dislocation, sprains etc. involving the ankle joint. Short leg cast may be either weight bearing or non weight bearing. If it is to be used for bearing a client’s weight during ambulation, it is fitted with a walking heel. The ankle joints are kept at 90 degree angle. The cast is applied from below the knee to the toes. The toes are left exposed.
4. Long Leg Cast (Above-knee Plaster)
This is used in the treatment of the fractures of the bones of the lower leg and thus involving the knee joint. It extends from below the groin to the toes.
5. Spica Cast
Spica cast may be applied to the hip, shoulder and thumb joints. A shoulder spica cast is a combination of a body jacket and a long arm cast. It is used in the treatment of fractures of the shoulder girdle, humerus, dislocation of the shoulder joint etc.
Hip spica extends from the mild trunk just below the nipple line down the entire length of one leg on the affected side. The cast has an opening around the buttocks and perineal region for the purpose of elimination and cleanliness. Hip spica casts are used to treat congenital dislocation of the pelvis, hip joint or fracture of the pelvic bones and femur. Shoulder or hip spica casts may be reinforced by plastering a stick or bar between the extended portions of the cast.
6. Body Casts
Two types of body casts are used – Minerva jacket and body jacket. A Minerva jacket covers the frontal and occipital regions of the skull and extends over the neck, chest, back, abdomen and iliac crests. The face, ears and upper extremities are exposed.
Body jacket extends from the upper chest to the pubis, exposing buttocks and perineal area. Some of the body casts include thighs.
Both Minerva casts and body jackets are used to immobilize the spine to promote healing of surgical spinal fusions, spinal injuries or to relieve degenerative disorders. Body casts may be used to immobilize the spine in a position of hyperextension to treat compression fractures.
Body casts, if applied too tightly over the chest and abdomen will interfere with the chest expansion during breathing and may cause abdominal discomforts. Body casts are sometimes prepared several days before surgery. It is bivalved and removed when dry and then it is reapplied when the operation is complete.
7. Bivalved Casts
Bivalved a cast means splitting it along both sides. A cast may be bivalved for the following purpose:
To allow space for tissue swelling when it is expected in an area.
To treat a surgical wound
To prevent uncomfortable abdominal distension
To facilitate skin care when skin damage is expected without disturbing the body alignment
To make a half cast which can be used as an intermittent splint to prevent deformities
To help the client to adjust gradually without a body cast
The top half is removed while the client lies supine and remains in the bottom half of the cast and vice versa. When reapplying the bivalved cast, be certain to handle the client carefully and take care not to pinch the skin between the two halves.
COMPLICATIONS OF PLASTER CASTS
1. Impaired blood flow
Signs and Symptoms: absence of pulse in the extremity below the plaster cast, Pallor, blanching or cyanosis of the skin, Pain, coldness of the skin, Swelling, Numbness, Motor paralysis.
2. Nerve damage
Signs and Symptoms: persistent and increasing pain, Numbness and Motor paralysis.
3. Tissue necrosis and infections
Signs and Symptoms: unpleasant odour, Feeling of ‘hot’ sensations, Drainage through the cast, Sudden elevation of unexplained body temperature.
4. Volkman’s ischaemic contracture
Signs and Symptoms: all the signs and symptoms of impaired blood flow. Absence of radial/pedal pulse, Infarction and necrosis of the muscles, Absence of finger/toe movement, Absence of pain which was intense in the beginning.
5. Cast Syndrome
Signs and Symptoms: prolonged nausea and vomiting. Abdominal distension, Vague abdominal pain.
6. Complications due to immobility
Signs and Symptoms: hypostatic pneumonia, foot drop, renal calculi, decubitus ulcer on all pressure points, stiffness of joints, constipation and retention of urine, lethargy, loneliness and depression, insomnia.
7. Surgical complications
Signs and Symptoms: phlebo-thrombosis and pulmonary embolism, wound infection.
PLASTER CASTS – Purpose, Articles Used, Types, Application. A Simple Learning for Nurses
Plaster casts made from plaster of Paris are devices that encase an injured part in order to protect, to support and to immobilize it during healing process and are used to prevent or correct a deformity.
1. To immobilize, to support and to protect a part of the musculoskeletal system during healing process
2. To prevent or correct deformity
3. To relieve pain associated with fracture of bone by relieving muscle spasm and preventing displacement of the fractured bone fragments
4. To maintain a particular position and enforce rest
ARTICLES USED FOR APPLICATION OF PLASTER CASTS
1. Plaster of Paris (gypsum salt)
Plaster of Paris is soft and malleable when moistened with water, but is hard and durable when dry. Plaster of Paris (anhydrous calcium sulphate) is chalky white powder made by a process that removes water from gypsum. In the process of making plaster of Paris, crystals of gypsum are broken up and reduced to powder and intense heat is applied. This removes water from the crystals. A chemical process of rehydration occurs when plaster of Paris is placed in water. The heat produced during this recrystallization, or ‘setting’ period can be felt in the newly applied cast.
A plaster cast becomes firm (sets) rapidly but it takes a long period to dry. During this setting period, there should be no movement which may produce a crack in the cast and makes the cast weak. A newly set plaster cast is called a ‘green cast’. It contains excess of water which adds to the weight of the cast. Eventually, this water evaporates leaving a dried cast which is light in weight and is porous. The porous nature of the plaster permits the evaporation of moisture from the skin. A cast attains its full strength, once an evaporation of complete water occurs. Plaster casts take variable time to dry. Setting is influenced by:
a. The type of plaster used
b. The thickness of the cast
c. The condition of the surrounding environment
d. The temperature of the water (warmer temperature speed up the setting time, while colder temperature slows down the setting time).
Plaster casts are applied by applying 5 to 7 or more layers of plaster bandages. Plaster of Paris bandages are available in individually wrapped pre-cut rolls of crinoline impregnated with plaster of Paris. The bandages are available for varying widths from 5 to 15 cm. they are available for varying setting periods. The strength of the plaster cast is determined by the number of layer of plaster bandages used. Plaster splints (slabs) may be used to strengthen and re-inforce area of casts which require an additional support.
REGARDING REMOVAL OF THE PLASTER CAST
1. Always get written order from the doctor for cutting and removal of the plaster cast. The length of time a client continue to wear a plaster cast varies and it depend upon the type and extent of injury, diseases, surgery and the rate of healing. For a simple fracture of the upper limb, the cast is cut off after 6 weeks and for the lower limb the cast is cut after 3 months.
2. When a cast is cut off, apply an elastic bandage for few days to minimize swelling.
Stiffness of joints which were immobilized may occur. The client should be given graded active exercises, massages and whirlpool bath etc. to increase the muscle strength and to restore the joint movements.
3. Removal of the cast is accomplished with an electric cutter which resembles a small electric saw with a circular blade. The appearance and the noise should be explained and be assured that he will not get hurt or injured by the instrument.
4. Record the removal of the plaster with date and time on the client’s record.
5. When the plaster is worn for a long time, the epidermal cells of the skin cannot flake off normally and it collects beneath the plaster. No forceful attempt should be made to remove this dead skin. Scrubbing the skin with strong cleaning agents should be avoided.
An application of a plaster cast is entirely a responsibility of doctor. The responsibility of the nurses lies in the preparation of the client, the articles, helping the doctor in an application of the plaster cast, after care of the client and the articles.
REGARDING PREPARATION OF CLIENT AND THE ARTICLES
1. Explain the procedure to the client prior to the application of cast; how he will be looked after in the cast especially in the body cast. Adequate explanations will relieve anxiety of the client.
2. Prepare the part for the application of the plaster cast. Clean the skin with soap and water and dry the area thoroughly. Shave the hairy part to prevent bad odor.
3. Examine the skin thoroughly for lesions, infections, dirt and foreign particles etc.
4. Check the pulse in an involved limb to verify the circulation before the application of the plaster cast. Mark the area where the pulse was felt with a skin pencil for future reference.
5. Protect the floor and garments of the client and the operator from plaster that my spill during the application.
6. Protect the skin area to be casted with stockinette and cotton padding to prevent skin irritation and skin damage. Special attention should be paid to the bony prominences. When stockinette or padding is applied under a cast, it must be smooth on the skin. Wrinkled material under a cast cause pressure areas and skin breakdown.
7. Prepare the client as for the general anaesthesia, if reduction of fractured bones are to be carried out under general anaesthesia prior to the application of the plaster cast.
8. All the articles are arranged in the plaster room according to the convenience of the doctor and the nurses. The following articles are required for the application of the plaster casts:
a. The plaster bandages (the number and width of the bandages are determined according to the area to be covered)
b. Stockinette or cotton wool for padding
c. Deep basin or bucket with warm water (the basin should be lined with paper or clothing to trap all the sediments of plaster settling at the bottom)
d. Strong scissors, plaster shears to cut the plaster
e. Tape measure
f. Skin pencil
g. Waterproof sheets, aprons and gloves
h. Soap, water and hand towel
REGARDING APPLICATION OF THE PLASTER CAST
1. Maintain the position of the client as desired by the doctor until the cast has started to set. It is important to hold the client precisely as the doctor wishes, so that the casted structures will remain properly aligned. Remember, a plaster cast will not benefit a client unless it is correctly applied in a correct position.
2. Never attempt to correct the position by pulling on the plaster bandage or by changing the position of the limb when the plaster is partly applied.
3. When supporting the newly casted areas, hold the cast on an open palm. Never grasp or pinch the wet cast with your finger tips because it will make indentations on the wet.
4. The primary object of the application of cast is to apply a smooth, strong and a correctly positioned cast. To make it smooth, the cast is continuously rubbed and moulded with moderate pressure exerted by an open hand until it is completely set. To make it strong, the cast is re-inforced by the slabs on certain areas of the body where strain will be more (at the back of the forearm and elbow, along the calf muscles and sole of the foot). To have a correctly positioned cast, place the body part in the normal functioning position.
5. After the first layer has been put on, the edges of the stockinette is doubled back at the top and bottom to form a neat finish. The subsequent turns are put on carefully so that the folded edge just appears on the finished plaster.
6. When saturating the plaster bandages, it is immersed vertically in warm water. When bubbles of air cease to rise from the bandage, it is picked up with both the hands covering the ends of the roll with the palms. It is then gently squeezed to remove excess of water, losing as little plaster as possible.
7. When applying the plaster, observe the rules for applying the roller bandages.
To function effectively and safely the plaster cast is applied neither too tight nor too loose. Every effort is made to apply a cast that will be comfortable as well as therapeutic. If it is too tight, it may cut off circulation. If it is too loose, it will not fulfill the intended function of maintaining the position of the desired parts.
8. The plaster cast must be applied as light as possible yet strong enough to withstand usage.
9. Following application of the cast, an X-ray film is taken (check X-ray) to verify the correct position of the body part. Subsequent films are taken whenever a cast is removed or applied.
10. If a leg cast is to be applied for bearing the client’s weight, it is fitted with a walking heel on the plantar surface.
11. Bone reduction should be done whenever the fractured fragments are displaced. They are brought in position and then the cast is applied to help in the healing of fracture in its correct position.
12. To prevent wastage of plaster bandages, never submerge more than one roll in water at a time, as the plaster gets destroyed if prepared too much in advance. Start soaking plaster only when the surgeon is ready to apply it. Soak the second bandage only after taking the first.
13. If the large cast being applied, it may be necessary to change the water in the bucket and replace it with fresh warm water. This helps to maintain the temperature of the water which helps to set the plaster quickly. Plaster residue in the water (left in the previous use) adhere to the new rolls of plaster causing the freshly dipped plaster to set too slowly, producing lamination and weakness of the cast.
14. Never empty the plaster laden water into the drainage system, because the plaster sediment will solidify and plug the drainage system. When changing the water, wait for the sediment to settle at the bottom of the bucket and then carefully drain off the water from the top of the bucket and dispose the plaster sediment safely.
15. If the plaster is to be bivalved, a metal strip should be included inside the plaster as it is applied, and along this metal piece, the plaster can be split causing no pain or discomfort to the client.
16. As far as possible all fingers and toes are left exposed in arm or leg casts to check for the circulation of blood and nerve damage.
The plaster is dated with a skin pencil on it and is recorded in the client’s record.
REGARDING CARE OF CLIENT IN PLASTER CAST
1. A wet plaster cast must be handled with greatest care. The cast must be supported as a whole. Do not attempt to move the client until the plaster is set.
2. A cast should not rest on the hard surface while drying, because continuous pressure will cause it to adapt itself to the contour of the surface and it becomes flattened.
Place supportive pillows along the entire length of a casted area during the drying process.
3. As soon as the cast is complete, the client’s skin is cleaned to remove excess plaster. Otherwise, the dried plaster may fall between the plaster cast and the skin and it may cause irritation of the skin.
4. Watch for swelling below the plaster. If swelling appears, split the cast longitudinally through all layers including the padding to relieve pressure.
5. As soon as the plaster is completed, check the pulse to verify that the circulation is not impaired by the plaster cast. If the pulse is not felt, it indicates constriction of the blood vessels by the plaster cast. The plaster should be removed and reapplied.
6. While the cast is drying, heat may be lost from the body due to evaporation of the water. The client may feel cold and chilled easily. During this period, provide the client with adequate covering while leaving the casted area exposed.
7. Heat is generated during the initial setting period of a cast, which is very uncomfortable to the client. The fan may be put on to cool down the body. Remember, very soon the client may feel cold and chilled due to evaporation of the water.
8. A cast should be dry from inside out. It is important that a cast is not heated with an artificial method because the outer side of the cast is dried soon with the heat applied, but the inner side will remain damp and can cause cracks in the cast. A rapid drying may cause the burning of the skin under the cast.
9. The plaster cast may become loose when the swelling of the tissues disappears. If it becomes loose, it has to be removed and reapplied again.
A casted extremity should be elevate to minimize swelling especially in the first 24 to 48 hours. Elevation may be done with pillows, slings etc. the foot should be elevated higher than knee, the knee higher than the hip in order to reduce the swelling.
10. Mattress with fracture boards beneath them are used for clients with plaster casts. A sagging mattress will tend to deform a green cast and may cause cracks in a dried cast.
Weight bearing is not permitted at least for first 24 hours after the application of the cast to prevent damage to the cast.
11. A client with plaster cast will require constant observation for the first 24 to 48 hours to detect the early signs of complications.
The complications may be caused by the following factors:
a. Swelling of the tissues under the plaster cast
b. Application of the cast that is too tight
c. Wrinkles in the underlying padding
d. Foreign objects pushed under the cast
e. Vascular or nerve damage sustained during the injury, fracture reduction, surgery or the application of the cast
f. Formation of vascular thrombosis or emboli
g. Indentations in the plaster
12. To prevent complications and to detect the early signs of complications, the nurse should make the following observations:
a. Skin color
b. Skin temperature
c. Peripheral pulse
e. Swelling and skin damage under the cast
f. Activity of the limb distal to the plaster cast
13. Never ignore any complaints made by the client however small it may appear to be.
If the client has a walking cast, the leg should be elevated by the use of sling when the client is ambulatory. When the arm rests in the sling, the fingers should be higher than elbow.
14. Protect the areas of cast near the buttocks and perineal region to prevent dampness and soilage. Waterproof materials can be smoothly placed under the cast edges and taped to the exterior surface of the dry cast.
15. When offering bed pans to the client with spica casts, the client should be carefully and comfortably placed over the bedpan. Support the back with pillows. An overhead frame with trapeze bar helps the client to lift his body up during the insertion of the bed pan. Slightly raising the head of the bed will prevent the fluid from running under the back of the cast during perineal toilet.
16. The pressure points require prompt and special attention to prevent decubitus ulcers. Skin care should include frequent inspection, frequent change of position, thorough cleaning and drying of the skin and the application of emmolient lotions etc. any skin damage should be reported and treated immediately.
17. A foot support should be provided to prevent foot drop of the uncasted foot.