302 W. I. Card and I. N. Marks 



the conserving action of the kidney, to deplete the body of 

 magnesium to any serious extent by taking a diet low in 

 magnesium. The opportunity occurred to us some four years 

 ago of treating a patient with an ileal fistula from which 

 extensive fluid and electrolyte losses occurred, and in whom a 

 magnesium-deficient state ultimately appeared. 



For the purposes of this paper the precise clinical details 

 are irrelevant; it is sufficient to say that the patient was a 

 woman aged 34, suffering from ulcerative colitis, who had had 

 performed a proctocolectomy with ileostomy. The immediate 

 postoperative course was satisfactory but it became necessary 

 to refashion the ileostomy a fortnight later, and this was 

 followed by intestinal obstruction for which a further opera- 

 tion was performed. An ileal fistula then developed. Such a 

 fistula results in large fluid and electrolyte losses. 



It is not of course possible in clinical practice to measure 

 electrolyte balances on all patients postoperatively, but it is 

 clearly necessary to have sufficient knowledge of their losses in 

 order to replace them effectively. The routine ward procedure, 

 which was followed in this case, is as follows: 



A fluid balance chart is kept on which the amounts of all 

 fluids given orally and by intravenous infusion are noted, as 

 well as all losses whether urinary, faecal, by aspiration or by 

 any other route. In patients such as this woman, where the 

 intake of food is important, the food taken is recorded on a 

 slip of paper, so that the dietitian may make some estimate 

 of caloric or protein intake. From the fluid balance chart, 

 with, if necessary, the estimation of electrolytes in any 

 aspirated fluid, the necessary amounts of fluid, water, sodium, 

 chloride, and potassium, are prescribed for the next 12 or 24 

 hours. Serum electrolyte concentrations are measured, daily 

 if necessary, as in this case. 



This procedure was carried out with this patient so that she 

 was kept in water, sodium, potassium, and chloride balance. 

 The CO 2 combining power remained within normal limits. 

 There was no rise in her blood urea and judging by the urinary 

 specific gravity reached the kidneys functioned well. Calcium 



