This is the protocol for Dehydration:



Let’s break it down!

This is probably THE most common condition we’ll ever treat, so let’s make sure we do it right.  Soldiers in the field are often chronically dehydrated.  Strenuous activity, heat, and the spread of viral/bacterial illnesses can affect entire units at one time.  This can pose a potential threat to resources when you have to treat large groups of dehydrated soldiers at one time.  The importance of good hydration practices at a unit level cannot be overstated.

Most people can tolerate a 3-4% decrease in total body water without any difficulty or adverse health effects. A 5-8% decrease can cause fatigue and dizziness. Loss of over 10% percent of total body water can cause physical and mental deterioration, accompanied by severe thirst. Death occurs at a loss of between 15%-25% of body water.  Although dehydration and hypovolemia (loss of blood plasma) often go hand in hand, it’s important to understand that these two are distinct from one another.  Someone who is dehydrated may not necessarily be hypovolemic, and vice versa.  Dehydration is more likely to cause electrolyte abnormalities.

If you really want to get into the science of hydration, check out the video below:

On a hot summer day when everyone’s in full battle rattle, it’s easy to assume that many of these soldiers will be dehydrated. Most of them, however, won’t come up to you and say “Doc, I’m dehydrated”.  They’re much more likely to complain of things like a splitting headache, nausea/vomiting, etc.  They can also experience lightheadedness when standing suddenly.  This is referred to as orthostatic hypotension, which is characterized by a sudden drop in blood pressure by 20mmHg systolic or 10mmHg diastolic.  You can test this by performing the following steps:

  • Step 1: Have the patient lay down in supine position for 5 minutes
  • Step 2: Take blood pressure (Ex. 112/76)
  • Step 3: Have the patient stand up or sit up for at least 1 minute, no more than 3 minutes
  • Step 4: Take blood pressure (Ex. 98/64) 

Some good things to tell your soldiers before they go out in the field is to check their pee and check their lips.  If at any point in time, their lips are dry or their pee is dark, then those are solid indicators that they are dehydrated and they need to drink water.


Image result for orthostatic hypotension

If they can drink, they will!  Giving every dehydrated soldier a bag of saline is a good way to burn through all of your supplies.  Have them fill up their canteen and start sipping.  Soldiers should be drinking anywhere between 2-6 canteens of water per day, depending on their activity level.  For those that are already dehydrated, adding in an electrolyte mix can be beneficial.  Be sure to avoid the mixes that have more caffeine in them than electrolytes (caffeine acts as a mild diuretic).  There are a lot of different oral rehydration solutions out there, but one that’s beginning to grow in popularity is Drip drop, which has about 3X more electrolytes than sports drinks and half the sugar.  Tossing two 21g packets of Drip drop into a full canteen is an excellent way to rehydrate soldiers.  As a bonus, soldiers tend to like the taste!  

Image result for drip drop


Many patients with dehydration will experience nausea and vomiting, further contributing to fluid loss.  These guys may be unable to tolerate any PO fluids so these will be the cases where we opt for intravenous fluids.  Although normal saline is typically the go-to, using another crystalloid fluid such as Lactated Ringer’s would be just as good, if not better!

Where To Buy Bags Of Normal Saline | IUCN Water

Although dehydration is a fairly simple condition to treat, it can be difficult if other disease processes are involved like gastroenteritis, pneumonia, etc.  Priority evacuation for the ones that won’t get better… and back to work for the rest!

Good luck out there!



Brandon Simpson, PA-C
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