ORIGINAL ARTICLES.: PNEUMATIC TOURNIQUETS: WITH ESPECIAL REFERENCE TO THEIR Cushing, Harvey

S urgeons and neurologists alike are familiar with the postoperative palsies of the extremities consequent upon the too energetic and prolonged application of an elastic tourniquet. Out of a considerable number of pressure paralyses, which have come under the writer’s observation during the past two years, eight of them have thus origi­ nated. The greater number of these were of the brachial type, the tourniquet having been em­ ployed to render bloodless the field at the elbow usually for resections of the joint. A thin, flabby arm, especially in these cases of joint disease and in spite of all precautions, lends itself readily to such an injury as the poorly protected nerves are easily compressed against the hard shaft of the humerus. The skilful application of the old type of rubber tourniquet, varying it for the in­ dividual so that it exerts a compression just suf­ ficient to shut off the arterial supply and yet not enough to harm the nerve trunks, is an art rarely acquired even by an adept hospital orderly, who may have had years of experience. There remain other objections to its employ­ ment. One of these concerns the technic of the operation. The tourniquet usually occupies a po­ sition on the borderline of the aseptic field, and when once applied must remain so until the com­ pletion of the operation. If once relaxed, and in certain procedures, in amputations or plastic op­ erations on aneurismal sacs for example this may be necessary in order to see whether there is a continuance of any arterial bleeding, it is most difficult to readjust the tourniquet again, should this be desirable, without dislocating all of the clean surroundings, . towels, etc., at the wound. A still further drawback from an elastic band, when tightly applied, is the ensuing vaso­ motor palsy, evidenced bv the flushing of the extremity peripheral to thesite of application. In a major amputation this produces the “ wet stump” oftentimes so annoying to an operator inasmuch as it necessitates drainage which other­ wise might have been avoided. Pain is another objection. In many operative procedures on the extremities, preferably carried out under local anesthesia, the temporary cessa­ tion of the local circulation is of great assistance. Patients, however, can endurethe discomfort of an elastic tourniquet-for a very brief period. It is furthermore a common surgical practice, and one, I think, of questionable merit, to apply an elastic ligature, when necessary to control hem­ orrhage, in cases of traumatic lacerations of the extremities and to wait until the “ shock” from the original traumatism wears away. Such a prac­ tice, from afferent impulses of pain due to the tourniquet alone, may add not a little to the al­ ready existing vascular depression. _ Thus the possibility of paralysis, the difficulties of observing the best technic during the applica­ tion, removal and especially of reapplication, and the pain when no general anesthetic is adminis­ tered are all familiar drawbacks to the common form of elastic tourniquet. I think they may be avoided in large measure by the use of tour­ niquets of another sort. The suggestion of an inflatable .tourniquet doubtless originated in the use of the distensible armlet of the Riva-Rocci blood-pressure ap­ paratus. On one or two occasions I had utilized the apparatus itself as a means of shutting off the circulation during cocaine operations on the hand, by holding the pressure slightly above that of the registered systolic arterial pressure. Objections are self-evident. Although the pressure of the armlet is relatively painless, its slow distention by shutting off the veins before the arteries, causes such an engorgement as to render a clean dis­ section most difficult. Consequently a similar armlet, though broader, of less distensible rub­ ber and of such quality that it would stand boil­ ing, was constructed, and by connecting it with a bicycle pump of sufficient size one or two quick strokes of the piston sufficed to fill it. Such an arrangement I have made use of many times for cocaine operations on the extremities with the greatest satisfaction. The tourniquet may be ad­ justed but not blown up until the moment of be­ ginning the operation, and by palpating a periph­ eral artery one can tell easily when a sufficient degree of inflation has been reached.* When op­ erating on minor cases without an assistant I have used a small bicycle foot-pump, the tourniquet either being adjusted well above the operative field before “cleaning up” or, having been boiled, placed around the member within the aseptic field just before operating. In similar fashion a larger and stronger form of cylinder than those which I have had constructed would answer for use on a muscular thigh or leg. There is a further and a therapeutic use to which this form of peripheral construction could well be put though I have had little personal ex­ perience with this particular variety of tourni-