From The Philadelphia Polyclinic, February and March, 1893. PRACTICAL DETAILS IN THE PREPARATION OF PLASTER OF PARIS BANDAGES.1 By H. Augustus Wilson, M. D., PROFESSOR OF GENERAL AND ORTHOPEDIC SURGERY IN THE PHILADELPHIA POLYCLINIC; CLINICAL PROFESSOR OF ORTHOPEDIC SURGERY IN THE JEFFERSON MEDICAL COLLEGE. I want, this evening, to make a practical demonstration of the proper method of preparing and using the plaster of Paris bandage, that you may all clearly understand the necessity for observing the petty details upon which the successful use of the plaster of Paris depends. This method of making impromptu splints, or apparatus, to hold any part of the body in an immovable position, is now of such a common use that it is only its supposed disadvantages that prevent its more extended employment. It is often stated that plaster of Paris was not used in a certain instance, or could not be used because, first, it was such a dirty proceeding, and second, because it required so long a time for the plaster to set, that the parts were apt to get out of position while it was hardening, and third, that it would crumble and break instead of remaining firm. All these disadvantages can be, and should'be, avoided, by care- ful attention to the details in the preparation, and in the application. Therefore, we will begin at the beginning and speak of the materials to be used. 1 An evening lecture delivered at the Polyclinic Hospital. This will be followed by a similar paper on the application of such bandages. 31 32 WILSON, Plaster of Paris is gypsum, which has had the water of crystallization driven out of it by heat, and then ground into a fine powder. It possesses a strong affinity to again take up this water of crystallization, from whatever sources it can, and resume its former condition as a stone. This water of crystallization may be absorbed from moist dress- ings, or from the atmosphere, and it not infrequently occurs that bandages that are perfect in appearance, are thoroughly useless because of the long time that has elapsed since they were made, during which time the plaster has absorbed moisture from the atmosphere. The method of testing the quality of plaster of Paris is by taking a small pinch of the powder between the thumb and finger and gently rubbing it; if small particles of grit are felt, it indicates that parts of the plaster have already absorbed water, and it is therefore unfit for use. The same test may be observed by taking a pinch of the powder again and placing the fingers under water, and then rub- bing in the same way as before. If, however, in both of these tests no grit is felt, and, under water, a thin creamy substance is formed, which is easily rubbed off the fingers, the plaster is in a proper condition for use. Where plaster has been kept for a long time, or where it is gritty, its con- dition can be very greatly improved. It may be re-dried by putting it in a metal dish, such as a pie-plate or iron pot, and placing it in an oven of a hot fire or over a gas-jet. As soon as it becomes heated, it will be observed that a process itdentical with boiling water is taking place. When this ebullition has entirely ceased, the powder is freshly kiln- dried. If the method of testing is again resorted to, it will be found that the gritty appearance and feeling will have disappeared, in a very large measure, leaving only the fine dry powder ready for use. If there are any lumps remain- ing, they may be removed by the use of a sieve. From what has been already said, it will need but a reminder that the plaster of Paris must always be kept in a hermetic- ally sealed jar, or in a very dry place. Now as to the material of which the bandage is to be PREPARATION OF PLASTER OF PARIS BANDAGES. 33 made. The materials most frequently resorted to, are the ordinary surgical roller bandage, made out of unbleached muslin; cheese cloth, made out of same material, and dif- fering from the former only in its having larger meshes; crinoline, a stiff gauze, and buttercloth, or bleached gauze. It is a matter of very great importance that the material used for the bandage should possess the property of absorb- ing water, and, therefore, the foregoing materials will be submitted to a comparative test in order to observe their relative value. As small pieces of the above are placed in a basin of cold water, it will be observed that the buttercloth sinks immediately; the crinoline more slowly, the cheese cloth and surgical roller bandage remain on the surface, and, at the end of an hour, will be found to be almost as dry as when they were put in the water. Therefore, I would recommend as the best material for making a plaster of Paris bandage, the commercial buttercloth. This material is made exactly like cheese cloth ; in fact, it is cheese cloth, which, by some process, has been bleached, and it is stiffened some, not by starch or sizing, but simply by being passed over heated rollers. This enables it to hold its shape, but it is not as stiff as crinoline, nor are its fibers covered with a sizing which will prevent its absorbing water. There are two brands of buttercloth on the market, known as the Reading and the Weymuth. Either of these materials may be bought in any length, one yard wide, for 3 to 5 cents a yard. Where the bandages are to be made in large numbers, I find it decidedly advantageous to purchase it in the original package, containing 50 to 100 yards, simply because of the convenience in preparing it. The surgical roller bandage may be readily and accurately torn in the requisite widths, but the cheese cloth and buttercloth can- not be torn straight, and therefore some other method must be resorted to, in the case of the buttercloth, in order to have the bandages of even width. If but a few bandages are to be prepared, the material may be cut into widths of 2J or 3 inches, with a pair of scissors, following a thread, or a long piece of bandage material may be rolled into as tight 34 WILSON, a form as possible, and then cut transversely with a sharp knife. This method has the advantages of rapidity, of accuracy, and of not requiring especially made appliances for the purpose. The next step will be the combination of the bandage material and of the plaster of Paris, and there are two ways of accomplishing this. One way is to apply the bandage to the part to be covered, and after a layer has been put on, to smear the so-called cream of plaster of Paris on the bandage; then another layer of bandage, and then more cream of plaster of Paris, and so on until sufficient thickness has been obtained. The cream of plaster of Paris referred to, is made by mixing the dry plaster of Paris powder with suffi- cient water to make it of the consistency of thick cream. This method has the disadvantage of being excessively dirty, because in the attempt to carry the cream from the basin in which it has been made, to the parts upon which it is to be applied, it is sure to drop over everything and to splatter all around, and it is therefore desirable to avoid this way, by the better way which I shall now describe. The simplest way of filling the meshes of a buttercloth bandage with dry plaster of Paris, is to spread the bandage to be rolled on a table at which you are sitting, to have a pile, of a pound or more, of plaster at your right hand, and while you roll the bandage with your left hand, to apply the powder smoothly on top of the bandage with the right hand, or, if you prefer, you may use a spatula or even a table knife. In this way a thin layer of the powder is evenly applied on top of the bandage, and in the process of rolling, it is squeezed into the meshes, filling all the interstices. Some of the powder will squeeze through and remain on the table, leaving parts of the bandage with an insufficient quantity, but this can be avoided by having some of the loose powder on the table directly under the bandage, as it is being rolled. Where only a few bandages are to be pre- pared, this plan answers every purpose. Its great disadvan- tage is that the fine powder spreads all around, going from the hands on the clothing, on the floor, and by the very PREPARATION OF PLASTER OF PARIS BANDAGES. 35 motion required in this manipulation, scatters throughout the room, to a greater or less extent. To avoid this dirt, and to facilitate the more even preparation of the bandage, I have devised a box or bandage roller, which, while it removes the objections already described, possesses the advantage of speed which is often an important item. The box I devised for the purpose is made by Mr. A. G. Gefvert, the Mechanician to the Hospital. It is 16 inches long, 5 inches wide and 5 inches deep, although any size box may be used for the purpose. In this box there is a movable diaphragm made of tin hinged at a point 12 inches from one end of the box. The extremity under the crank pin, upon which the bandage is rolled, is curved so as to conform to the in- creasing size of the band- ace while it is being rolled. The sides of this tin dia- phragm, beginning at the hinge, and extending 6 inches, are turned up at a right angle, simply to pre- vent the escape of the plaster over the sides. Five inches from the hinge there is what I call for convenience, a distributor, which is simply a gate, hinged to the upright sides of the distributor, at such an angle as to make an even distribution of the plaster on the bandage as it is being rolled. It is kept in place and enabled to make gentle downward pressure, by means of rubber elastic bands, attached to the 6 er& (o P"M 36 WILSON, turned up sides of the distributor, at a point about 3 inches from the hinge. The free moving end of the diaphragm has also a rubber band attached to and connecting with the box, so as to hold the diaphragm always in contact with the out- side layer of the bandage, from the beginning of the rolling to the end. The free space of the box beneath the distributor is used to hold the dry plaster of Paris, which is brought up and placed on the bandage behind the distributor, by means of any convenient form of scoop. The method of using the apparatus is as follows : The diaphragm being entirely free from plaster of Paris, the crank pin is inserted, and the gauze is passed over the hinge of the diaphragm, under the distributor, and then under the crank pin. One or more turns of the crank pin are made simply to catch the gauze. Sufficient plaster of Paris is now placed behind the distributor, and the crank pin turned in such a way that the bandage is kept in contact with the diaphragm. The left hand is used to guide the bandage so as to roll straight, and, at the same time, to make a gentle restraining force that may be required to prevent its being rolled too loosely. When the bandage has become large enough for use, or when the length required has been exhausted, the left hand grasps the bandage firmly, and a quick reversed turn of the crank pin is made with the right hand, withdrawing the crank, the bandage is placed to one side, the rubber elastic band at the extremity of the diaphragm is loosened, the diaphragm raised so as to throw all remaining plaster of Paris back into the box. It is then ready for another bandage. From what has already been said about the difficulty of keeping the dry plaster of Paris, it will be apparent that the same difficulty will be met with in preserving the plas- ter of Paris bandage after it is rolled. It is, therefore, important that each bandage, shortly after its preparation, should be tightly enveloped in previously prepared paraffin paper, the ends of which should be twisted or fastened in such a way as to make it practically impervious. If this is done, the bandage may be put away for months, and, when used, will be in as good condition as when originally prepared. 78 PRACTICAL DETAILS IN THE APPLICATION OF PLASTER OF PARIS BANDAGES.1 By H. Augustus Wilson, M. D., PROFESSOR OF GENERAL AND ORTHOPEDIC SURGERY IN THE PHILADELPHIA POLYCLINIC; CLINICAL PROFESSOR OF ORTHOPEDIC SURGERY IN THE JEFFERSON MEDICAL COLLEGE. The bandage being ready for use, it will be important to consider the preparation of the parts to be bandaged, so as to have the necessary material required for that purpose in readiness for use. The objections to applying the plaster of Paris bandage directly to the skin of the patient are three- fold ; first, that any hair that may be upon the parts will be caught and firmly imbedded in the plaster, as it sets, ren- dering the subsequent removal excessively painful to the patient, and very difficult; the second objection is that the bony prominences being brought into contact with the unyielding surface of the plaster of Paris would be apt to produce abrasions of the skin, or ulceration, besides being very painful and rendering the continued use of the appa- ratus impossible ; and the third is that the plaster of Paris would set or become hardened much more slowly from being in contact with the, more or less, oily skin. It therefore becomes important to resort to the use of some material which will, at once, remove all the objections to which I have just alluded. A non-absorbent, or a slowly absorbent, material would remove the first two objections but not the third. Therefore such material as unbleached muslin, or cheese cloth, or any similar material, would not be suitable for the same reason that they were inapplicable in the preparation of the bandage itself. The use of gauze employed in making the bandage, would remove all of the objections except the second, and that only in part unless quite a number of layers were used. I have found that the use of the patent absorbent lint is a most desirable material for this purpose. It is cut into 1An evening lecture delivered at the Polyclinic Hospital. In the February num' ber similar details are given for the preparation of the bandage. APPLICATION OF PLASTER OF PARIS BANDAGES. 79 bandages of the required width, by means of a sharp knife, in the same manner that the buttercloth is prepared, and has been found to answer every requirement. Its capabil- ity of absorbing water has been found to enable the plaster of Paris bandage to set more rapidly than when other materials have been used. Even after all the precautions already taken, it will be found that the plaster of Paris will harden very slowly, requiring twenty to thirty minutes or more, if plain water, either hot or cold, be used. Experience has taught that the use of a large handful of ordinary table salt, in a basin of water, assists in the hardening process, lessens the time required in setting, and prevents to a great measure, the subsequent crumbling which is such an annoyance to the patient. Cold water is to be preferred, because in the process of reabsorption of the water of crystallization, and getting back to its mechanical condition of stone, heat is generated to a sufficient degree to be positively painful in patients who are especially susceptible to heat. Therefore if hot water had been used to begin with and supplemented with the heat generated and already referred to, it would become unbearable to almost any one. Plaster of Paris should not be placed in water until just at the time it is to be used. The best rule is to have it immersed at the same time that the patent absorbent lint is being applied to the parts. There should be enough water to entirely cover the band- age, and about one or two minutes will be required, accord- ing to the size of the bandage, for it to become thoroughly saturated. As soon as the bubbles of air cease rising to the surface of the water, a thorough saturation has been accom- plished, and the bandage should be taken out in both hands and gently but firmly squeezed so as to get rid of the excess of water, and the end of the bandage loosened. In this condition it can be carried across the room, if necessary, without dropping any plaster on the floor, and it is suffi- ciently moist to render its easy and rapid application. Should the ravelings of the sides of the bandage gather in a 80 WILSON, tangle during the application, they may be cut loose by a pair of scissors which is preferable to attempting to pull them out, for in the attempt to pull them out more threads are disengaged and will cause more delay in trying to get rid of them. While the bandage is being applied the parts to be cov- ered should be held accurately in the position in which they are to remain, and either with the disengaged hand, or better by an assistant, the plaster should be rubbed thor- oughly so as to squeeze the still soft mass into all of the meshes of the bandage, with the object of making a homo- geneous and compact mass, composed of the plaster of Paris, with the threads of the bandage material running through it. If the bandage has been properly made, and applied as directed, it will never be necessary to rub in any additional cream, for the additional plaster of Paris will simply give increased weight and bulk without increasing the strength of the bandage. In most cases, four layers will be ample to rigidly restrain any part of the body, and the additional layers will not add to its efficiency. I cannot too strongly urge the necessity of leaving bare the extremity of the limb to be covered with the plaster of Paris because it affords an indicator of the condition of the circulation beneath the bandage. In applying the plaster of Paris dressing to the leg or foot, the ends should all be left so that they can be watched without disturbing the apparatus, and should the circulation become impaired to a sufficient extent to indicate decided pressure, the apparatus should be removed at once, other- wise sloughing and gangrene may result. It is also impor- tant in holding the dressing, while it is drying, to avoid pressure at any point, as would be made if the fingers were to press into the bandage, because these finger marks make elevations upon the inside of the bandage, which may not only be sources of great annoyance to the patient, but be productive of serious injury. Firm gentle pressure by the entire hand will avoid this, and make a smooth exterior to the bandage. It should be borne in mind that plaster of APPLICATION OF PLASTER OF PARIS BANDAGES. 81 Paris always shrinks in setting, and it is therefore very important to apply it loosely to allow for this. Various methods have been devised to facilitate the removal of this form of fixed dressing, a few of which I shall speak of now. The simplest method of doing it is by the use of a knife, when the bandage is wet, or freshly applied. If the blade of the knife is held obliquely, and great care is exercised, the bandage may be cut down and the edges which have been turned up in so doing may be pressed back into position. If great care is not taken, there is always danger of cutting the patient, and to avoid this numerous methods have been recommended. Dr. A. T. Steele, of St. Louis, has devised a special tool to be slipped under the dressing and carried down as the knife proceeds in its work. Upon this the knife would strike when the dressing was cut entirely through. To avoid the necessity of purchasing the special appliance for the purpose, the same may be accomplished by placing a slip of metal, one inch wide, and long enough to extend the entire length of the part to be covered, and being placed between the skin covering and the plaster of Paris, the knife may be used with perfect fearlessness and the plaster thereby easily removed. The plaster of Paris, however, sets so very quickly that it is often found very difficult to cut through its entirety, upon its becoming very hard. If this is the case, or if the bandage is to be cut several days after it has set, the line of incision may be softened with vinegar, or the same object may be accomplished by the use of water. The disadvantages of this method is, that, in the case where the apparatus is to be reapplied, the edges are left in a rough condition, necessitating trimming, thereby making the case very much smaller. It has been recommended that fine steel wire be used between each layer of the plaster of Paris as it is being applied, and after the plaster has become thoroughly set and hard and dry, that these wires should be torn out, one by one, carrying with them the overlying fibers of the band- 82 WILSON, age material. I have, however, found the most satisfactory- way to be by the use of a saw and a strong pair of shears. The saw cuts down quickly through the plaster of Paris and there is an absence of resistance upon reaching the skin protector. Any points that are still resistent may be cut through with the shears, and suffers thereby, no loss of material, so that the cast may be reapplied and fit accu- rately the parts from which it has been taken. If it is desired to have a small hole of 2 or 3 inches in diameter, through which to supply subsequent dressing to the wound, a large wad of cotton of about the size of the fist is to be applied where it is desired to have the hole. This will make a decided mound when the plaster is fin- ished, and makes it very easy to cut with a knife into the cotton. The cotton being removed it will be found that the edges are all turned up, making a convenient receptacle for retaining subsequent dressing. When a plaster of Paris dressing or jacket is to be worn for a prolonged time, or where it is to be reapplied, all the edges should be carefully trimmed and bound. This binding may be done by ordinary rubber adhesive plaster or by a new plaster of Paris bandage. The objection to the rubber adhesive plaster is that it becomes very dirty, aud it gives an unsightly finish to the pure white of the plaster of Paris. The binding by the plaster of Paris band- age is in keeping with the rest of the apparatus, and answers every purpose. After the apparatus has become thoroughly dry, hard and firm, it may be protected by varnishing it, and this has the additional advantage of keeping it clean. Then by a damp rag, the entire surface may be rubbed whenever it is necessary. Should any part of the appara- tus begin to crumble, it would be a waste of time to attempt to patch it, because the new material would be on the out- side only, and the break would continue to increase. It will save time to make an entire new cast, strengthening it at the point where the previous break has taken place.