US1794215A - Method of and apparatus for injecting medicated solutions - Google Patents

Description

Feb. 24, i 1931. p, 'n1-Us 1,794,215 METHOD 0F AND APPARATUS FOR INJECTING MEDICATED soLTIQNs Filed vJune 14, 1928 2 Sheets-Sheet l INVENTOR Feb. 24, 1931. P. 'rrrus 1,794,215

METHOD OF AND APPARATUS FOR INJECTING MEDICATED SOLUTIONS Filed June 14, 1928 2 Sheets-Sheet 2 4 E 300C: f l

3 250m a l J4 Ei zooc" El; 2 |5ocl r-l Q, 50cl OPEN a I2 Patented Feb. 24, 1931 UNITED STATES PATENT OFFICE PAUL TITUS, OF PITTSBURGH, PENNSYLVANIA Application led .Tune 14,

This invention relates generally to a method of and apparatus for injecting medicated solutions, and particularly to the intravenous injection of dextrose solutions.

In one clinic with which the inventor is connected, dextrose solutions in the amount of 20,000 cc. per month are being injected intravenously. In spite. of the fact that such large quantities of medicated solutions are being regularly employed in many clinics, a common and frequently harmful mistake in the intravenous administration of such solutions is that the solutions are administered too rapidly. It is a fact in the majority of clinics certain known physiological fact-s as to the rate at which the body is able to take up and utilize injected dextrose solutions are almost totally disregarded, with the result that dosage becomes inaccurate, large amounts of the medicine are wasted by being expelled through the kidneys and the expected therapeutic effect is thus vitiated in direct ratio to the speed at which the injection is given. It is probable, moreover, that this is also a common cause of certain unfavorable reactions which occur following dextrose injections.

It has been previously determined that an individual can utilize .8 gram of injected dextrose per hour for each kilogram of body weight, and that to give more than this amount by injecting` a solution too rapidly simply results in the excretion of the solution from the body and proportionate loss of its medicinal action.

Based on many experiments, the average single dose of dextrose given intravenously to an average sized adult (150 pounds or 56 kilograms) should be 7 5 grams. In most 1nstances it is preferred to usethe dextrose 1n a 25% solution, and such solution may be produced by dissolving grams of dextrose in 300 cc. of freshly double distilled water.

Bearing in mind that the average individual can uitilize up to .8 gram of dextrose per kilogram of body weight per hour, it will be apparent that a 25% solution of dextrose should be injected into an average sized adult (56 kilograms) at a maximum rate .of 3 cc. per minute. A slower rate of flow will even- 1928. Serial No. 285,301.

tually give the patient his full dose at an absorbable rate, but a faster rate will simply result in theloss by elimination of the surplus from the body. A full dose of a 25% dextrose solution formed by dissolving 7 5 grams of dextrosejin 300 cc. of double distilled water thus requires approximately minutes in its administration or approximately 12/3 hours. The corresponding rate for other concentrations of solutions may be easily calculated. For example, a 10% solution formed by dissolving one gram of dextrose in 10 cc. of water may be given as rapidly as 7.5 cc'. per minute to a person of this same average weight. The data and calculations are all approximate.

If the patient weighs less than the average, there will be some slight loss on this account, but if he weighs more than the average, he merely fails to receive the maximum dose in the shortest possible time.

Since the rate of {iow of dextrose solution injected intravenously for medical purposes must be so regulated that not more than a specified amount of the dextrose be injected int-o the human body in a given time, this necessitates varying the rate of injection in accordance with the percentage strength of the solution. 7itl'1out a computing or indicating device this must be laboriously figured out for cach different injection. Without a regulating device or valve, inaccuracies in controlling the rate of flow are inevitable, even if the proper rate has been determined by such calculation.

It has been established that when administering a dextrose solution to children, the rate of flow shouldbe about one-half that used in administering to adults, and that for Vinfants, the rate should be reduced to at least one-fourth the rate employed in administering to an adult.

It thus becomes apparent, in order that the doctor will not be misled as to the results obtained, and in order not to waste the solution which is being injected, and yet to administer the solution as rapidly as possible, and in order to avoid possible harmful strain on the sugar threshold of the patients kidneys, that a device should be employed by which the rate of flow of the solution can be accurately regulated and be adjustable for various strengths of solution, and that the medicated solution should be so administered as to give the maximum results and still require the minimum time. It is also essential that this device be so constructed as to be surgically sterilizable.

In addition to the above, it has been found that harmful eHects follow such injections of dextrose solutions if they are not sufficiently warm. The use of a heating device to regulate and maintain a fairly constant temperature near to or above that of the body is, therefore, desirable. Unfavorable reactions frequently follow the injection of solutions medicated With salt or other therapeutic agents, as well as the injection of citrated p blood for purposes of infusion, and a percentage of these reactions are due to the loss of heat or cooling of fluids during injection. It is desirable, therefore, to heat and to maintain and regulate the temperature o f all therapeutic intravenous" injections. Various heating devices have been designed for somewhat similar purposes, but none of these seem to embody the essential feature of being completely sterilizable by boiling, by autoclaving or by immersion in antiseptic liquids. This is a necessity in the case of an instrument to be used for the injection of sterilized medicated solutions into the veins of patients in order to avoid contamination of the solution and infection of the patient during the injection operation.

The apparatus hereinafter fully described is adapted to accomplish these results.

In the accompanying drawings, wherein the present preferred embodiment of my in- Vention is shown the valve for controlling the rate of flow of the medicated solution;

Figures 6 and 7 are views in side elevation showing opposite sides of the valve shown in Figure 5; and

Figure 8 is a longitudinal sectional view of a heating element adapted to control the temperature of the medicated solution.

Referring to the preferred embodiment of the invention, and particularly to Figure 1, there is shown a device for the intravenous injection of medicated solutions, comprising an infusion burette 2 and a measuring burette 3, connected through a passage in the body member 4, which is mounted upon a suitable base 5. Mounted on the body meniber 4 is a dial 6, adapted to cooperate with a pointer 7, connected to a valve 8, which controls the flow of solution from the bui'ettes 2 and 3 to a rubber tubing 9, which leads to a heating element 10. The opposite end of the heating element is connected by means of tubing l1 to a needle 12, which may be inserted into a vein of the patient.

Referring more particularly to Figures 2 to 7, inclusive, the body member 4 is mounted on the base 5, by means of screws 13, which also fasten a handle 14 to the apparatus. The body member 4 is provided with a conduit 15, adapted for connection at its right hand end with a conduit 16, provided in a tube'17, connected to the infusion burette 2. The opposite or left hand end of the conduit 15 is adapted to cooperate with the passages in a valve 8, in order to control the rate of flow from the burettes through the conduit 15, valve 8 and outlet 19, leading to the heating element 10, as shown in Figure 1.

By rotating the infusion burette 2, the opening at the lower end of conduit 16 may be-aligned with the conduit 15, thereby allowing the solution to flow from the burette into the conduit. Hook-shaped stops 2O and 21 are mounted on the body member 4 and are adapted to cooperate with a lug 22 mounted on a collar 23 connected to the tube 17, in order to limit the rotationof the burette 2 and to prevent accidental displacement of the burette from the body member 4. The burette 2 is marked, as shown, to indicate the number of cubic centimeters of medicated solution contained therein.

Intermediate the infusion burette and the valve 8 the body member 4 is provided with an opening 24 adapted to receive the lower end of the measuring burette 3 and to connect the burette with the conduit 15. The lower portions of the infusion burette and the measuring burette which are mounted in the body member 4 preferably are made of the'same size so that if the measuring burette, which is made of glass, should be broken, it may be withdrawn and the infusion burette may be placed in the opening 24.

The valve 8, which controls the rate of flow of the medicated solution, is adapted to be received in an opening 25, provided in the body member 4. The ,valve 8 is provided with an axial passage 26 which, when the valve is in a position such vas to align the axial passage with the conduit 15, allows the medicated solution to How rapidly from the outlet 19. The valve 8 is further provided with a circumferential groove 27, which, as shown in Figure 5, is connected at its vleft hand end with the left hand end of the axial groove 26. The right hand end of thegroove 27 terminates just short of the conduit 15. On its opposite side, the valve is provided with a second circumferential groove 28,

which is preferably of an equal depth transversel of the valve throughout its length but W ich tapers longitudinally Yof the valve to a point from its right hand to its left hand end (Figure 6). On the upper end of the valve, the pointer 7 is adapted to cooperate with the scale 6, to indicate the rate of How of the medicated solution.

As shown in Figure 3, the scale is marked to indicate the position to which the pointer 7 should be brought inorder 'to Hush the apparatus, and to indicate the various positions to which the pointer should be brought in order to allow the medicated solution of different densities to How at different rates. The scale is marked to indicate the rates at which various strength solutions should be administered. As indicated, a 25% dextrose solution should not be administered at a rate greater than 3 cc. per minute and a 10% dextrose solution should not be administered at a greater rate than 7.5 cc. per minute. They scale also indicates the positions to which the pointer should be moved in order to produce these various Hows. f

In Figure 8, a heating device 10 is shown which is adapted to control the temperature of the medicated solution. As shown, the heating device is made of glass and is shaped so as to provide a conduit 30, through which the medicated solution flows. A heating element 31, which is formed of a material such as copper wire, is wound around the wall. 32 which forms the conduit 30. Surrounding the heating element 31 and in spaced relation thereto is an outer wall 33 adapted to enclose the heating device 10, throughout the major portion of its length.

At its right hand end, the heating element 31 is connected through a lug 34to an adjustable screw 35, and at its opposite end the heating element is connected through a collar 36 to a binding post 37. At the right hand end of the heating device 10 there is provided a bimetallic thermostatic element 38 which is connected at its right hand end to the binding post 39. Wires 40 and 4 1 connect the binding posts 37 and 39 to a plug 42.

In the administration of medicated solutions using the apparatus above described, the instrument is sterilized by boiling, by autoclaving or by soakingl it in alcohol and is thereafter assembled. Hot distilled Water is run through theI apparatus with the pointer 7 arranged in the Hushing position indicated on the dial 6. Thereafter, the valve 8 is turned `so that the pointer coincides with the zero position of the scale shown in Figure 3. A preheated medicated solution such, for example, as a dextrose solution, is introduced into the burette 2, and the burette turned so as to allow passage of the solution into the measuring burette 3 through the conduit 15.

The valve and pointer 7 are then set at the proper point for the concentration of dextrose solution which is being used and as soon as all air bubbles are eliminated and the How is established at the needle, the vein kmay be entered.

The medicated solution Hows from both the infusion burette 2 and the measuring burette 3 into the conduit 15. In the Hush position, the axial assage 26 aligns with the conduit 15, thus allbwing a fast rate of How of the solution from the device. When the Valve is in the lposition shown in Figure 5, none of the solution passes the valve 8. However,'if the valve is turned in a clockwise direction as indicated by the arrow, the con duits 27 and 28 connect with the conduit 15. Flow is then established from ,right to left of the apparatus shown in Figure 5 through conduit 15, circumferential passage 27, axial passage 26 and circumferential passage 28, to the outlet 19. The circumferential passage 28 tapers to a point (as shown in Figure 6) so that as the valve is rotated in the direction indicated by the arrow, the outlet 19 is connected with a larger portion,r of the passage 28 and the rate of How is thereby increased.

From the outlet 19, the medicated solution flows through the tube 9 into the right hand end of the heating device 10, shown in Figures 1 and-8, and from the left hand end of the heating device 710, the solution Hows to the injecting needle, through the rubber tube 1l. The bimetallic element 38, shown in Figure 8, is so constructed that when it is heated it tends to bow downwardly. When the plug 42 is connected to a source of electricity and when the electrical contact 38 is in contact with the tip of the adjustable screw 35, current Hows from the -source through the wire 40 to the binding post 37, heating element 31, binding post 34, adjustable screw 35, bimctallic element 38, and out through the wire 41. The medicated solution flowing through the heating device therebv becomes heated. The bimetallic element 38 is heated and bows downwardly, thus breaking Contact between the adjustable screw 35 and contact point 38 and cuts off the flow of current through the heating element 31. Asthe solution cools, it cools the element 38, so that it bows upwardly and again establishes contact with the tip of the adjustable screw 35. The temperature of the solution flowing through the heating device is governed by the relative position of the adjustable screw 35 and bimetallic element 38. The temperature may therefore be regulated by adjusting the screw.

If it is desired to determine if the rate of How of the solution is the same as indicated by the pointer 7, the infusion burette 2 is rotated so as to prevent How of the solution from the burette into conduit 15. The solution being injected Hows entirely from the measuring burette 3 into the conduit 15 and through the passages' previously described into a vein of the patient.

Since the capacity of the measuring bu rette 3 is small as compared with the capacity of the infusion burette Q, the droi in the level of the solution in the measuring ,burette is rapid and may be easily observed. The rate of flow may be easily determined by timing with a Watch, thus giving a check on the flow indicated by the pointer 7.

Although any suitable material which is not attacked by the medicated solution may be employed to form the apparatus shown in Figure 2, I prefer to use either Monel metal, which'is approximately 65% nickel and 35% copper, or a chromium, nickel alloy of iron, the chromium running from 17 to 20% and the nickel from T to 10 C/v. If desired, either of these materials may be nickel plated.

It is to be understood that the form of the invention herewith shown and described is to be taken as the preferred embodiment of the same, and that the invention is not so limited but may be otherwise embodied Within the scope of the following claims.

I claim:

l. device of the character described comprising a body portion provided With a conduit, an infusion burette rotatably mounted in said body portion and adapted upon rotation to either establish or cut off communica tion between said burette and the conduit, a valve arranged in said body portion and adapted to cooperate with the conduit in order to control the rate of flow of the solution from the device, and means for determining the rate of flow of the solution from the device Without interrupting its flow.

2. A device of the character described comprising a body provided with conduit, an infusion burette rotatably mounted in said body portion and adapted upon rotation to either establish or cut olf communication between said burette and the conduit, a valve arranged in said body portion and adapted to cooperate With the conduit in order to control the rate of flow of the solution from the device, and a measuring burette connected to the conduit for determining he rate of iioW of the solution `from the device Without interrupting its ow When said infusionI burette is in a position to out 0H flow from Said infusion burette to the conduit.

3. In the method of injecting medicatedv solutions in which an infusion burette and a measuring burette are employed, the step of determining the rate of flow of the solution which comprises causing the solution to flow onlyvfrom the measuring burette, and tim ing the flow from the measuring burette.

4. An apparatus for injecting medicated solutions, comprising a body portion provided with a conduit, an infusion burette and a measuring burette communicating with the conduit, a valve for controlling the flow of solution in the conduit, and means for causing all the solution passing through said valve to be supplied from said measuring burette whereby the rate oflow through the valve can be determined by observing the measuring burette.

5. An apparatus for injecting medicated solutions comprising a body portion provided With a conduit, an infusion burette and a measuring burette, each connected through valves with the conduit, and a conduit valve for controlling the flow of solution in the conduit, the arrangement being such that all of the solution passing through said conduit valve may be supplied from said measuring buiette whereby the rate of flow through the valve can be determined by observing the measuring burette.

In testimony whereof I have hereunto set my hand.

PAUL TITUS.'

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