The control of water and electrolyte balance after surgery.

T H E great majority of patients who This post-operative response affects undergo a surgical operation are able, many of the metabolic processes of the within a very short while, to return to a body, indeed probably more than we are normal intake of food and drink, so that, yet aware of, but . its most important with regard to fluid balance, they present effects are on the handling by the body of no problems which demand more than water and electrolytes. Speaking in general common sense in their management. However, in the minority of patients, particularly those submitted to major surgery on terms these effects can be described as an impairment of the kidneys' normal ability to excrete from the body excess loads of the alimentary tract, care is required if water and salt. As a result, if too much they are to be maintained in fluid and electrolyte balance in the days immediately following operation. The need for this care arises from two causes: first, because such patients are liable to develop complications such as paralytic ileus which can in themselves easily lead to severe electrolyte disturbance; secondly, because of the metabolic changes which fluid is given, it accumulates in the body, leading to salt and/or water retention. Such a retention is, of course, the end result of these metabolic changes but it is by observation of the details of such retentions that we derive our knowledge of the changes themselves. During the past few years my colleague Dr. Lewis and I have carried out a series of balance follow surgery. This metabolic response to studies before and after operation which surgery occurs after all operations, indeed, have enabled us to get a reasonably clear after all forms of trauma. In general its picture of these changes. Our results have magnitude varies in direct proportion to been published elsewhere (Le Quesne and the magnitude of the trauma, with the Lewis, 1953), and the description that result that, whilst it can be neglected after follows will largely be based on our observations, which I should point out revealed little that was new. I shall not take up your time now with technical details, but before describing our results one or two points need emphasis. The essential basis of our observations was the operations of average severity, an understanding and recognition of its effects is vital in the care of those submitted to major operations.