If possible, refer the patient. If you cannot refer him, treat him like this.
For example, correct any hypovolaemia, treat a burn, or severe muscle injury. Even if you can refer him, do this first.
Chart the water and electrolytes he has lost and those he has been given. Correct his calculated water and electrolyte deficit before you start the period of fluid restriction.
Give him his measured output of water, plus an estimate of his insensible loss. Give it as water by mouth, or intravenously as 5% dextrose. Don’t give him any solutions containing electrolytes, except those necessary to replenish his losses, because he cannot excrete them.
His measured output is the total volume of his urine, and any vomit, or watery diarrhoea.
His insensible loss in a temperate climate will be about 500 ml, in the tropics it may be 1000 ml or more.
CAUTION! (1) Don’t include blood, plasma, or plasma substitutes in these estimates. (2) Don’t allow his thirst to influence the volume of his intake. Watch that he does not over hydrate himself. (3) The dose of many antibiotics, especially gentamicin, needs to be modified in the presence of renal failure. (4) Don’t give him diuretics.
If possible, do this daily. He should lose about 500 g daily after his initial fluid replacement. If he gains weight, he is retaining fluid and is being over hydrated.
(1) Remove all dead and dying tissue with a really thorough wound toilet. (2) Avoid hypoxia. If he needs an anaesthetic, try to use local anaesthesia. (3) Don’t give him potassium in any form. There is potassium in milk and orange juice, barrows and Ringer’s lactate, in soup and meat, and in many drugs. (4) Minimize catabolism with a high energy no protein diet.
If he has no nausea, gastric suction, or intestinal lesions, try to to give him at least 400 g of glucose or lactose, or, failing these, sucrose, daily by mouth or by nasogastric tube. This will give him 6.7 MJ (1,600 kcal).
Give him 20 ml of 50% glucose with 10 units of soluble insulin into a large vein, preferably his vena cava, repeated 6 hourly (19.2).
Every 24 hours during this phase give him 1500 ml of fluid plus his urine output for the previous 24 hours. Give him a litre of 0.9% saline and a litre of 5% dextrose and the balance as half strength Darrow’s solution. This contains 17 mmol/l of potassium. The normal potassium requirements are about 35 mmol/daily. He may need 6 to 10 litres of fluid a day.
If his urine specific gravity is still very low at 4 days, you are probably keeping his diuresis going by overinfusing him. Try cautiously reducing his fluid intake.
CAUTION! Don’t start protein feeding until he is passing at least 1500 ml of urine a day, and his blood urea is below 25 mmols (250 mg/dl). Starting it too early increases the danger of uraemic complications.