IV FLUIDS

Question 1

What are IV crystalloids?

Answer 1

Water-based solutions with small solutes that freely cross capillary membranes; first-line fluids in EMS.

Question 2

What are IV Colloids?

Answer 2

FLUIDS with LARGE Molecules that REMAIN Intravascular LONGER by INCREASING Oncotic Pressure;

RARELY Used Prehospital.

Question 3

What does Tonicity describe?

Answer 3

A FLUID’s Osmolar EFFECT on Cells

• ISOTonic
• HYPOTonic
• HYPERTonic

Question 4

Define Isotonic IV fluids.

Answer 4

Osmolarity similar to plasma (≈275–295 mOsm/L);

no net fluid shift into or out of cells.

Question 5

Common Isotonic fluids in EMS.

Answer 5

Normal Saline (0.9% NaCl),
Lactated Ringer’s,
Plasma-Lyte.

Question 6

Primary indications for Isotonic fluids.

Answer 6

Shock,
trauma,
dehydration,
sepsis,
hypotension,
medication carrier

Question 7

Key RISK of Large-Volume Normal Saline.

Answer 7

HYPERChloremic Metabolic Acidosis.

Question 8

Why is Lactated Ringer’s often Preferred in TRAUMA?

Answer 8

MORE Physiologic Electrolyte Profile;

LESS Acidosis than NS.

Question 9

Define Hypotonic IV fluids.

Answer 9

Lower osmolarity than plasma; fluid shifts into cells.

Question 10

Common Hypotonic fluids.

Answer 10

0.45% NaCl,

D5W (functionally hypotonic).

Question 11

EMS indications for Hypotonic fluids.

Answer 11

Rare;

Severe Hypernatremia with Medical Control.

Question 12

Why are Hypotonic fluids avoided in Head injury?

Answer 12

They INCREASE Cerebral Edema

Question 13

Define hypertonic IV fluids.

Answer 13

Higher osmolarity than plasma; pull fluid out of cells into the intravascular space.

Question 13

Common hypertonic fluids in EMS.

Answer 13

3% NaCl, D10W, D50W.

Question 14

Indications for hypertonic saline.

Answer 14

Severe hyponatremia with neurologic symptoms; TBI with herniation signs (protocol-dependent).

Question 15

Key risk of rapid hypertonic saline administration.

Answer 15

Osmotic demyelination syndrome.

Question 16

Preferred glucose solution for adult hypoglycemia?

Answer 16

D10W (titrated, lower extravasation risk).

Question 17

When is D50W used?

Answer 17

Severe adult hypoglycemia when D10W unavailable; use cautiously.

Question 18

Why is D5W NOT a volume expander?

Answer 18

Glucose is metabolized, leaving free water that shifts into cells.

Question 19

Example of a colloid fluid.

Answer 19

Albumin

Question 20

First-line IV fluid for undifferentiated shock?

⸻

Answer 20

Isotonic crystalloid (e.g., NS or LR).

Question 20

Why are colloids uncommon in EMS?

Answer 20

No proven mortality benefit, higher cost, potential renal and coagulation risks.

Question 21

Fluid choice in Sepsis (PreHospital)?

Answer 21

Aggressive Isotonic Crystalloids;

Titrate to Perfusion.

Question 22

Fluid strategy in uncontrolled hemorrhage.

Answer 22

Controlled isotonic resuscitation;

Avoid Overloading before Hemorrhage Control.

Question 23

Best Fluid choice in Traumatic Brain Injury.

Answer 23

Avoid hypotonic fluids; Consider Hypertonic Saline per protocol.

Question 24

What must be Reassessed AFTER Every Fluid Bolus?

Answer 24

Lung Sounds, Blood Pressure/MAP, Mental Status, Perfusion.

Question 25

Your 23-year-old patient has reportedly been ill for three days with a high fever, chills, nausea, and vomiting. His skin is cool and pale and has a delayed skin turgor response. His heart rate is accelerated while his respirations are shallow and fast. His blood pressure is borderline hypotensive, and he has a decreased level of consciousness. Suspecting dehydration, which of the following IV fluids would be most appropriate to administer to this patient? A Isotonic solution B Hypotonic solution C Nonelectrolyte solution D Hypertonic solution