Yesterday, I wrote about the (lack of) effectiveness of forcing hypernatremia in the management of TBI. However, we do know that some of our head injured patients have trouble maintaining a normal sodium level, and if it drops quickly or too far, hyponatremia can certainly cause problems. Trauma professionals have a number of tools to help fix this, including salt supplements or tablets, saline infusions, or even hypertonic saline in more difficult cases.
But what about using a sports drink to replace electrolytes? Isn’t that what athletes do? There are quite a few of these sports drinks on the market, and new ones seem to appear every week. Common examples are Gatorade, Powerade, Muscle Milk, Vitamin Water, 10-K Thirst Quencher, and many more. What if your brain injured patients eschews the salt tabs and insists on pounding down sports drinks all day?
Here is a table from an old sports medicine paper that describes the composition of a number of sports drinks from back in the day. Some, like Gatorade, are still around. (Click image to see a bigger, readable version)
Note that the electrolyte results are in mg/250cc, so I will translate to meq/liter for you. Gatorade had the highest sodium concentration at the time, 20meq/L, and one of the lowest potassiums at 3meq/L. The majority of the current day sports drinks have about the same electrolyte composition. Note that they are all a bit hyperosmolar (300+ mOsm), and this is made possible by added carbohydrate from some type of sugar. The carb is usually in the form of sucrose, dextrose, and/or high fructose corn syrup (yum!).
Bottom line: Your typical sports drink is equivalent to D30 in 0.1 normal saline. Not good for your TBI patient when consumed for sodium supplementation. It will actually drive the serum sodium down when consumed in quantity. Make sure your patients steer clear of this stuff until their brain injury is healed and they are running their next marathon.
Reference: The Effectiveness of Commercially Available Sports Drinks. Sports Med 29(3):181-209, 2000.