Surgery, with Special Reference to Podiatry Part 33

+Novocaine.+ This drug is one-seventh as toxic as cocaine but is also weaker in action. It does not cause vascular constriction but has a preliminary vasodilator action. Like quinine, it has a decidedly irritating action when injected. It has a decidedly toxic effect when used in stronger solutions than 2 per cent. and causes tonic and clonic spasm. In a 1 per cent. solution it is probably safest and best as an anesthetic and one-half ounce of such a solution may be injected without fear of unpleasant consequences.

Its dose is said to be about seven grains, but this may often be the cause of alarming symptoms, and half of this quant.i.ty would perhaps be a safe limit. The duration of anesthesias of fairly strong solutions is about fifteen minutes; the action is more prolonged if used with adrenalin.

Various combinations of drugs besides adrenalin are employed with novocaine. Fischer recommends its use with thymol, but even so, it is not efficient for a longer period than twenty or twenty-five minutes.

Novocaine is frequently used in alcoholic solutions for injection in neuralgic subjects. The commercial tablet of novocaine and adrenalin is convenient for office use.

+Alypin.+ This substance occurs as a crystalline powder, easily soluble in water, alcohol and ether, and makes a neutral solution.

Alypin is in every respect the equal of cocaine though not quite as strong. Schleich has found that its use, in conjunction with minute quant.i.ties of cocaine, permitted of a reduction of the entire amount of anesthetics necessary to accomplish insensibility.

In its use on mucous membranes it does not cause any anemia and therefore no secondary bleeding occurs. This is a great advantage also in the examination of mucous membrane lined cavities, such as the eye, nose, throat and urethra, inasmuch as after the application of cocaine, the blanching of the membrane conveys no idea of the real condition of the parts.

Because of the results he obtained, Schleich now recommends the following solutions for infiltration:

1. Cocaine 0.1 Alypin 0.1 Sodium chloride 0.2 Distilled water 100.

2. Cocaine 0.05 Alypin 0.05 Sodium chloride 0.2 Distilled water 100.

3. Cocaine 0.01 Alypin 0.01 Sodium chloride 0.2 Distilled water 100.

For other operative procedures of a minor character, it has been found that one-fourth per cent. to one-eighth per cent. is sufficient. For application to mucous membranes, as in the urethra, nose and throat, 1 per cent. to 2 per cent. has proved effective.

+Stovaine.+ Stovaine is used more for spinal anesthesia than for local purposes; it is said to work well in inflamed tissues.

Several drugs have been used because of their lessened toxicity and many are constantly being tried but to be abandoned because of their inefficiency or irritating qualities. None of them are as efficient as cocaine and the weak solutions of Schleich are about as active as stronger solutions of many of these and are not more toxic.

Among the other cocaine subst.i.tutes in general use are betaeucaine, tropacocain, anesthesin, and subcutin.

These all find a special field of usefulness, but for general work, are limited, because of some disadvantages which each and all of them possess.

Individual selection plays an important part in the use of a local anesthetic, and one operator, by practical experience, may obtain results with a given drug, which another fails to achieve.

The essential feature to be remembered by the practising chiropodist is, that the use of any drug employed for anesthetizing purposes, even though but local, should be safeguarded in every way.

+Cold.+ The methods of using ether, rhigolene, or ice and salt, to produce cold, are slow and unsatisfactory. If cold is to be used to produce local anesthesia the most efficient and convenient method of applying it is by means of _ethyl chloride_. This fluid is very volatile and is best controlled by having it in air-tight tubes. When not in use, a valve covering one end of the tube prevents leakage.

When the valve is pressed upon, the orifice of the tube is opened and the heat of the hand forces out a fine stream of the liquid which is directed upon the parts to be frozen. Rapid evaporation causes intense cold. The nozzle should be held about fifteen inches from the area to be acted upon. When the spray strikes the integument, redness almost instantly results but in a few seconds the part becomes hard and white. This condition indicates local insensibility and lasts about two minutes. If the action is slow, it can be much hastened by gently blowing upon the parts to increase the rapidity of evaporation.

The refrigeration method of local anesthesia is of limited usefulness and is recommended only for the opening of felons and abscesses, for removing wens from the scalp and back, and for producing a painless area in which a puncture is to be made. It must be borne in mind that sloughing and ulceration of the skin are liable to follow the use of cold.

Work under this form of anesthesia must be done with rapidity not always consistent with thoroughness, and should therefore be employed only when a single incision or puncture is indicated.

The pain incident to subsequent thawing is severe and, in general, is about as hard to bear as an incision without an anesthetic.

For the purposes of practical podiatry, the chiropodist is advised to use a subst.i.tute for cocaine rather than the cocaine itself when local anesthesia is necessary. In the clinics of the School of Chiropody of New York, novocaine, quinine and urea hydrochloride, and alypin are preferred, and no single instance of toxemia has ever been experienced. There have been cases in which the anesthesia did not prove thoroughly effective, but, in the main, these drugs have well answered the purposes of their use.

THE END