Parenteral Fluid Therapy

Administration of fluid by any root other than the alimentary canal (per oral) i.e. intravenous, intramuscular, subcutaneous or into bone marrow is called Parenteral Fluid Therapy.

Intravenous route is by far the most common method for parenteral fluid therapy. Mostly, the median cubital vein in the cubital fossa is used for venepuncture.

Important Solutions commonly used:

# 5% Dextrose 

  • Isotonic solution that supplies calories but not electrolytes.
  • Used when the patient requires replenishment of his blood volume along with some nutrition, but no electrolytes.
  • Particularly used in the immediate post operative period when Na excretion is considerably diminished by renal conservation.

# Isotonic (0.9%) Sodium Chloride Solution

  • It is isotonic and contains Sodium and chloride ions in the concentration almost similar to that of plasma.
  • It should not be used in first 24 hours after surgery due to natural sodium conservation.
  • One important fact is that it contains a high concentration of Chloride as compared to that in plasma and imposes an appreciable load of excess Cl on the kidneys that cannot be readily excreted.

# Ringer's Lactate Solution

  • Its main advantage is that it has almost similar electrolyte concentration as ECF (extracellular fluid) and the pH remains normal even  if infused in large quantities.
  • This solution is best to be used in hypovolemic shock while awaiting for blood.
  • The chief disadvantage is its slight hypo-osmolarity with respect to sodium.

# Darrow's Solution

  • This is the only solution which contains more potassium than available in the plasma or ECF.
  • This is the best solution to combat hypokalemia.
  • The rate of infusion should be slower than other solution to avoid hyperkalemic state.