(0.9% sodium chloride solution also known as NS)
*Note: Normal saline should not be confused with Normosol-R. They are not the same.

Brand

No specific brand names; there are multiple manufacturers

Availability

• Solution: 250 mL, 500 mL and 1000 mL bags.

Pharmacology

Normal saline (0.9% sodium chloride) is an isotonic crystalloid solution. It is a source of water and electrolyte replacement. It closely approximates the composition of extracellular fluid (ECF) in the body. Normal saline is useful in replacing fluid loss and ECF electrolyte loss. It is also useful in wound irrigation and for inhalation in nebulization.

Normal saline solution has pH of 5.5 (4.5 to 7.0). Its composition, osmolarity, and ionic concentration are shown below for 1 litre of solution:

One litre of 0.9% Sodium Chloride contains:

154 mEq of sodium ion = 154 mmol/L

154 mEq of chloride ion = 154 mmol/L

Osmolarity=308 mOsm/L

Normal saline solution is substantially excreted by the kidney.

Indications

Used in cases of:

• hypovolemia as a result of fluid loss due to trauma
• in cases of dehydration for rehydration and maintenance
• as a replacement for fluid loss in chronic renal failure in small animals.
• for inhalation in nebulization therapy
• may be used as an irrigating solution in wounds

Drug Interactions or Contraindications

• Possible risk of sodium retention when used along side of corticosteroids.
• Use with caution in rats with congestive heart failure, kidney disease, or obstruction of the urinary tract since overhydration may occur more easily.

Adverse Reactions

CV: overhydration can increase workload of the heart and precipitate congestive heart failure

Resp: rapid breathing, pulmonary edema with overhydration

Metabolic:  fluid and electrolyte imbalances leading to muscle weakness if used inappropriately

Dosage Recommendations

Dose can be dependent on weight and severity of dehydration.

Suggested dosing per references are:

50 mL to 100 mL/kg/24 hr; SQ, IV, IO (intraosseous)  ¹

or

60-80 mL/kg/24 hr, dependent upon severity of dehydration; SQ , volume to be divided in two separate dosings given 12 hours apart. Administer by tenting the skin on the back over the area of the shoulder blades, and inserting needle into the subcutaneous tissue. Sites for administering over the area of the shoulder blades may be alternated from the center either to the left or right when choosing to administer the bolus in two smaller volumes at one time. ¹²

or

40 mL to 80 mL/kg/24 hr; IV, if animal not drinking. ¹⁰

or

For a 400 gm rat approximately 16 to 32 mL per day. If giving IP or SQ, it is recommended that it be in divided doses (example: 4 times/day) given during the day, and to be kept to approximately 5 mL per site to prevent skin distention and pain.  ⁹

Locations for giving SQ fluids are the fleshy area scruff of neck (at back over shoulder blades), and the fleshy part of right or left hind quarter.

The solution should be warmed in a water bath prior to giving by IV, SQ, IP or IO. Note, do not overheat solution or burns can occur.

Considerations

• ALWAYS assess level of dehydration before giving by IV, SQ, IP or IO!
• Auscultate breath sounds for rales.
• Use with caution- may result in electrolyte imbalance.
• Recommended storage at room temperature.
• A one liter bag of solution has a 6-month expiration date.