Diagnosis.—Although the well established methods of clinical examination have not been superseded, the chief advances in surgical diagnosis of late years have been due to a more exact use of radiology (q.v.). Though shadow pictures are open to misinterpretation and may mislead, these methods as a whole have led to much greater accuracy in the localisation of morbid con ditions in various organs, or in establishing the fact that they are normal. Advances in the chemical investigation of the blood and urine have made it possible to estimate the functional ability of the kidneys with considerable accuracy. The importance of this cannot be overestimated in considering the probabilities of sur vival of a patient after a major operation on the urinary system.
Though surgery cannot be regarded as a preventive art there are certain conditions in which it may be properly characterised as such. The early recognition and removal of diseased lymphatic organs such as the tonsil and the appendix are undoubtedly reducing the incidence of certain chronic and acute diseases which may follow the retention of a diseased organ in the body. Another example may be cited in the early operation on the common forms of hernia (q.v.). This condition is now customarily operated on almost as soon as it is recognised, fre quently in childhood; as a result, the gross and disabling ruptures with their concomitant danger to life, commonly met with in the past century are now relatively rare. Preventive medicine on the other hand, is gradually removing, as it should, from the sphere of surgery many conditions hitherto treated by the knife. In most civilised communities, rickets (q.v.) has been eradicated or is treated so early that operation is seldom necessary.
Remarkable experimental re sults in animals have been published from time to time in regard to the transference of organs and tissues from one animal to another. These results in animals can be applied to a limited degree in man. It has not been found possible successfully to transplant organs or tissues of one species to another. Success in this respect can only be claimed if the transplant survives and retains its original cell form and functions. Skin, fascia and bone are the tissues which can be usefully transplanted from one part of the body to another.
Pre-operative management of the pa tient will concern his general condition, the preparation for the anaesthetic and the cleansing of the skin in the operation area. Before an operation the patient should be in as good a physical state as possible. For one who is reduced or anaemic, infusion of fluid or even transfusion of blood may be required. In the case of a patient suffering from diabetes the proper dose of insulin or glucose is administered. As regards preparation for an anaesthetic, severe purging and prolonged starvation are now avoided. If the anaesthetic to be administered is ether, a small dose of atropine is given half an hour before the operation to limit the excretion of mucus in the air passages during the operation. Morphia is sometimes given beforehand to calm a nervous patient. Pre
paratory skin preparation need not exceed the dictates of ordinary cleanliness. The most generally employed method of sterilising the skin immediately before operation is after shaving to paint it with a solution of iodine or picric acid in spirit.
This is effected by boiling them from five to fifteen minutes in water. Strong chemical antiseptics or spirit are often employed to steril ise edged instruments which would be blunted by boiling. Ligature materials used within the wound are now usually made of catgut. These are specially prepared (whereby different degrees of dura bility are obtained) and sterilised by various processes. Silk and thread are sometimes used for special purposes and are sterilised by boiling in water. Sutures for the skin, which are removable, are commonly made of silkworm or salmon gut and are sterilised in the same way. Dressings and wound coverings are most effec tively disinfected by exposure in an autoclave to superheated steam at a temperature of about 250° F for 20 minutes. Sterilisa tion by hot air from its less penetrating power is limited in appli cation to instruments which would be damaged by boiling in water. Formalin vapour is also of use for instruments of this type.
In all operations the surgeon wears a sterile gown, cap and mask, and protects his carefully cleansed hands with sterilised rubber gloves. During operation care to avoid shock to the pa tient on the lines already indicated is taken. The operating thea tre is kept at a temperature above 70° F, and unnecessary ex posure of the patient is avoided. When shock is inevitable infusion of saline solution or blood may be carried out during the operation.
This will be directed to avoid the compli cations secondary to anaesthesia. The patient is kept warm in a well-ventilated room. Some vomiting is to be expected after ether anaesthesia. Fluid is administered in small quantities by the mouth as soon as the patient regains consciousness. In some conditions fluid administration may be given by the rectum or subcutaneously. Diet is kept to fluids for a few days. A meas ure of starvation at this stage, so long as plenty of fluid is given, does not prejudice the patient's recovery. A return to normal diet will depend upon the nature of the operation and the idiosyncrasy of the patient.
The normal clean surgi cal wound is dressed with sterile gauze which may be left in place till the stitches are due for removal; this will probably be about a week after operation. In those cases in which suppuration is present either as the result of a pre-existent abscess or from surgi cal infection, the wound will be drained by a tube or wick, and mild antiseptic dressings are applied at frequent intervals.
The period of time during which the patient is kept in bed necessarily depends on the mechanical state of affairs, especially in regard to abdominal wounds. In general, time will be given for substantial healing of the abdominal incision before the patient gets up—that is to say—two to three weeks.