plaster of paris

PLASTER OF PARIS:

PLASTER OF PARIS by Dr BABU.S KMC,kurnool

HISTORY:

HISTORY The writings of Hippocrates discuss in the management of fractures , recommending wooden splints plus exercise to prevent muscle atrophy during immobilization .

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The Ancient Egyptians used wooden splints made of bark wrapped in linen. Ancient Hindus treated fractures with bamboo splints The ancient Greeks also used waxes and resins to create stiffened bandages The Roman , in AD 30, describes how to use splints and bandages stiffened with starch

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Arabian doctors used lime derived from sea shells and albumen from egg whites to stiffen bandages. The sixteenth century the famous French surgeon Ambroise Paré ; (1517-1590), promoted the use of artificial limbs made casts of wax, cardboard, cloth, and parchment that hardened as they dried

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The innovation of the modern cast by four Military Surgeons , Dominique Jean Larrey , Louis Seutin , Antonius Mathijsen , and Nikolai Ivanovich Pirogov The first commercial bandages were produced from Germany (1931), and were called Cellona

DOMINIQUE JEAN LARREY(1768-1842):

DOMINIQUE JEAN LARREY (1768 - 1842) One of his patients after the Battle of Borodino in 1812 whose arm had to be amputated at the shoulder , was evacuated immediately following the operation and passed from Russia, through Poland and Germany. On his arrival at his home in France the dressing was removed and the wound found to be healed. Larrey concluded that the wound had been undisturbed had facilitated healing. After the war, Larrey began stiffening bandages using camphorated alcohol, lead acetate and egg white in water.

LOUIS SEUTIN (1793 - 1865):

LOUIS SEUTIN (1793 - 1865) Used cardboard splints and bandages soaked in a solution of starch and applied wet. These dressings required 2 to 3 days to dry, depending on the temperature and humidity of the surroundings Suetin’s technique for the application of the starch apparatus formed the basis of the technique used with plaster of Paris dressings today

WILLIAM ETON(British):

WILLIAM ETON ( British ) Who described a method of treating fractures that he had observed in Turkey. that Gypsum (plaster of paris ) was moulded around the patient’s leg to cause immobilization. If the cast became loose due to a reduction in swelling, then liquid gypsum was poured into a hole to fill the space.

ANTONIUS MATHIJSEN(1805 - 1878):

ANTONIUS MATHIJSEN (1805 - 1878) developed a method of applying Plaster of Paris bandages emphasized that only simple materials were required and the bandage could be quickly applied without assistance. The bandages hardened rapidly, provided an exact fit and could be windowed or bivalved easily

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used coarsely woven materials, usually linen, into which dry Plaster of Paris had been rubbed thoroughly. The bandages were then moistened with a wet sponge or brush as they were applied and rubbed by hand until they hardened.

NILOLAI IVANOVICH PIROGOV (1810-1881):

NILOLAI IVANOVICH PIROGOV (1810-1881) Plaster of Paris dressings were first employed in the treatment of mass casualties in the 1850s during the Crimean War He had observed the use of plaster of Paris bandages in the studio,who used strips of linen soaked in liquid plaster of Paris for making models

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Pirogov's method involved soaking coarse cloth in a plaster of Paris mixture immediately before application to the limbs, which were protected either by stockings or cotton pads. Large dressings were reinforced with pieces of wood

How to prepare plaster of paris:

How to prepare plaster of paris Plaster of paris is made from crystalline gypsum by heating in controlled conditions (120 c – 160 c) 2(CaSO4.2H2O)+Heat 2(CaSO4,1/2H2O)+3H2O Gypsum Plaster of paris Water The POP powder then spread onto gauge bandage which sets to hard cast when soaked in water

POP SETTING:

POP SETTING POP rapidly absorbs water which forms growing solid crystals of CaSO4.2H2O 2(CaSO4,1/2H2O)+3H2O 2(CaSO4.2H2O)+Heat Plaster of paris Water Gypsum crystals During this time heat is generated( exotherm ) as a result of ch emical activity(hydration)

Stages of setting:

Stages of setting Initial set - <10 min - crystals become longer and start to interlock - end of the working time - if the cast is manipulated after the initial set it will be weak - if immersed in cold water initial set will be delayed , working time lengthened - in warm water (< 50 c) initial set will be accelerated > 50 c the setting rate will slows,> 100 c no set

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Final set -forming a rigid structure around the gauze mesh -heat is generated at this time -end of the exotherm period - 10 - 45 min

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Hard set -crystals are completely locked together, excess water will be lost by evaporation -strength of the cast increases considerably during first 24 -72 hrs -the plaster is then able to withstand considerable forces

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- if the cast subsequently absorbs excess water,it will weaken - drying out will be delayed in cold or moist conditions - eccelerated in warm and dry environment - denotes end of the drying out period

Preparing to place a splint:

Preparing to place a splint • Expose the injured extremity completely before splinting • Clean, repair, and dress all open wounds before applying any splint • Check for neurovascular compromise • Choose the appropriate size and shape of splint to be used – Goal is to cover ½ circumference of the extremity without overlap

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• Prevent stiffness and loss of function by: – Preparing extremities to be Splinted in their functional position – Preparing extremities to be Splinted against gravity

Minimize swelling/edema:

Minimize swelling/edema • Rest, Ice, and Elevate • Ice-apply to area where there is no plaster and not more than 15-20 minutes/hr at a time for first 2 days – Longer may numb the extremity – shorter may not affect swelling Elevate the limb above the heart level

PADDING:

PADDING To protect skin soft tissue and bony prominences from pressure and abrasion and for cast removal To protect the skin from thermal injury during setting Over padding will reduce closed fitting of cast and permits excess movement at # site resulting in impaired healing

PRINCIPLES OF CAST MAKING:

PRINCIPLES OF CAST MAKING PADDING : -apply stockinet over the area to be plastered -then apply spl orthopedic padding overlap each turn by 1/3 in order to secure layers padding is specially important in a) swelling is present/expected b) limb is thin,bones are superficial c) when electric cutters used

:

APPLICATION : get ready equipment and water(25 c-35 c) Pt in comfortable position and clothing protected and understand what is going to happen if Pt is tense , cast will loose and inefficient desired position secured and held corrrectly

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bandages of the correct size are immersed in water at a time , held until bubbling stops ends are gently squeezed and expel water (not too much-will become unworkable) unrolls the wet bandage around the limb in an even manner , minimum tension directed towards the centre of the bandage

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only circular and spiral turns , reverse turns will lead to ridges inside the cast , moulding done by constant smoothing with wet palm when the required thickness obtained , trim to ensure range of movement at Jts not immobilized(this should be done while the cast is wet) Pt is instructed in taking care of the cast

HOW TO APPLY:

HOW TO APPLY

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For slab after immersed in water ,immediately remove , the layers must be pressed together and bubbles excluded , if this is not done the layers become brittle when dry and can separate

Setting depends on:

Setting depends on The less water is used, the more linear expansion occurs. Potassium Sulphate used as an accelerator sodium borate as a retarder in order that the plaster can be caused to set more quickly or slowly

How do you know if the splint is too tight:

How do you know if the splint is too tight If patient feels numbness, tingling, or increased pain, If the fingers or toes start turning blue If the fingers or toes become swollen

care of the splint:

care of the splint • Do not get the splint wet. Use plastic bags to cover the splint while bathing. • Do not walk on the splint. • Do not stick anything down the splint to scratch or itch. This may lead to injury and infection

Complications of splinting:

Complications of splinting • Rarely occur if applied correctly • Most common : sores, abrasions, and secondary infections from loose or ill-fitting splints • Less common :neurovascular compromise from tight fitting splints, contact dermatitis, and thermal burns from heating of plaster, deep venous thrombosis,

Follow up:

Follow up • Instruct patient should return if numbness, tingling, increased pain and impaired sensation • Re-evaluate in 48 hours for neurovascular compromise 5 P’s : pain, pallor, paresthesia, pulselessness, and paralysis • Orthopedic evaluation in 7-10 days for casting

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thank you