Fluid Selection in EMS Settings

General Principles

The American College of Critical Care recommends balanced crystalloids, like Lactated Ringer's, as first-line fluid therapy for most patients, while 0.9% saline should be reserved for specific indications such as traumatic brain injury, severe hyponatremia, or metabolic alkalosis 1, 2, 3
Balanced crystalloids are preferred for most resuscitation scenarios due to lower risk of hyperchloremic acidosis compared to normal saline 2, 3
Normal saline should be limited to a maximum of 1-1.5L when used, due to risk of hyperchloremic acidosis 1
Fluid choice should be guided by the patient's underlying condition, with special considerations for specific clinical scenarios 1, 4

In cases of traumatic brain injury, normal saline is strongly recommended as first-line fluid therapy 4
Normal saline helps correct sodium deficits without diluting serum sodium further in patients with severe hyponatremia 4
The relative acidifying effect of normal saline can help correct metabolic alkalosis 5
Balanced solutions like Lactated Ringer's are preferred for resuscitation in trauma with significant blood loss, such as hemorrhagic shock without traumatic brain injury 2
Balanced crystalloids are preferred to reduce risk of kidney injury and hyperchloremic acidosis in sepsis 5
Lactated Ringer's does not significantly worsen lactic acidosis despite containing lactate 5
Lactated Ringer's is traditionally preferred for initial fluid resuscitation in burn patients 2

Lactated Ringer's should be avoided in traumatic brain injury patients, as normal saline is preferred 1, 4
Lactated Ringer's should be avoided in patients with severe liver dysfunction due to impaired lactate metabolism 5
Lactated Ringer's should be avoided in patients with severe hyperkalemia, as it contains potassium 4
Normal saline should be avoided in patients with severe acidosis, especially with hyperchloremia 1, 5
Normal saline should be avoided in patients requiring large volume resuscitation due to risk of hyperchloremic acidosis 1

Both fluids should be administered according to the patient's clinical condition and hemodynamic response 1
In hemorrhagic shock, a strategy of restricted volume replacement is recommended until bleeding is controlled 1
Target systolic blood pressure of 80-90 mmHg in hemorrhagic shock without traumatic brain injury 1