The dose of sodium chloride administered to a person with intentional salt poisoning can be estimated from the serum sodium concentration. The author is from St. James’s University Hospital in Leeds, England.


excess serum sodium in mmol/L =

= (measured serum sodium level in mmol/L) - (normal serum sodium level in mmol/L) =

= (measured serum sodium level in mmol/L) – 140


excess serum sodium in mmol =

= (excess serum sodium in mmol/L) * (extracellular fluid volume in liters)



• Methods for estimating total body water are discussed in Chapter 2. For the implementation I will use the method from Race and Rathbun (02.12.04), which gives a rough estimate.

• Extracellular fluid represents about 45% of total body water.


Each 17 mmol sodium indicates 1 gram sodium chloride.


grams of sodium chloride administered =

= (excess serum sodium in mmol) / 17


Each 5 mL level teaspoon delivers about 6 grams of salt.


number of level teaspoons of salt administered =

= (grams of sodium chloride) / 6



• This assumes that the administration was shortly before presentation, so that the measured serum level reflects the peak serum concentration.


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