IV Fluids

Fluid therapy management is determined by the fluid’s ability to cross capillary membranes and its tonicity relative to human plasma.


Type Examples Clinical Characteristics
Crystalloids Normal Saline (0.9%), Ringer’s Lactate, Hartmann’s Solution Electrolyte solutions; redistribute rapidly to the interstitial space (require a 3:1 volume ratio).
Colloids Albumin, Hydroxyethyl Starch (HES), Gelatins Large molecules exert oncotic pressure; remain intravascular longer, but have a higher cost and allergic risk.


High-Yield Clinical Pearls:

  • Normal Saline (0.9\%): Excess use can induce hyperchloremic metabolic acidosis.
  • Balanced Solutions: Ringer’s Lactate is often preferred for large-volume resuscitation due to its electrolyte composition being closer to plasma.
  • Albumin: Reserved for specific cases like cirrhosis with refractory hypotension or severe hypoproteinemia; rarely superior to crystalloids for general sepsis.
  • Resuscitation Endpoints: Target adequate perfusion (Mean Arterial Pressure, urine output, lactate clearance) while strictly monitoring for fluid overload, which leads to pulmonary edema and impairs wound healing.

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