How can you rinse a rat’s nose with saline solution?

How can you rinse a rat’s nose with saline solution? - briefly

Use a sterile 0.9 % saline solution delivered with a calibrated micropipette or fine‑gauge syringe while the rat is lightly anesthetized, applying 0.1 ml per nostril and allowing the fluid to drain naturally. Ensure the catheter tip does not contact tissue to avoid injury and maintain gentle pressure throughout the irrigation.

How can you rinse a rat’s nose with saline solution? - in detail

To perform a nasal lavage on a laboratory rat, follow these steps:

1. Prepare isotonic saline

   • Dissolve 9 g of sodium chloride in 1 L of sterile distilled water (0.9 % NaCl).
   • Filter through a 0.22 µm membrane and store at 4 °C; use within 24 hours.
   • Warm to 37 °C before application to avoid thermal shock.

2. Set up equipment

   • Micropipette or syringe (1 mL) with a 27‑30 G blunt‑ended needle or a calibrated catheter.
   • Small animal anesthesia system (isoflurane vaporizer) or injectable anesthetic (e.g., ketamine / xylazine).
   • Disposable gloves, sterile gauze, and a clean work surface.

3. Induce anesthesia

   • Place the rat in an induction chamber with 3–5 % isoflurane in oxygen until loss of righting reflex.
   • Transfer to a maintenance platform, reduce isoflurane to 1–2 % to keep the animal at a surgical plane.
   • Verify lack of response to toe pinch.

4. Position the animal

   • Lay the rat in dorsal recumbency on a warm pad.
   • Gently extend the head by supporting the neck with a fingertip, keeping the airway open.
   • Use a small towel to expose the nostrils without compressing the facial structures.

5. Administer the lavage

   • Load 0.2–0.3 mL of warmed saline into the syringe.
   • Insert the blunt needle just into the external naris, avoiding deep penetration that could damage the turbinates.
   • Depress the plunger slowly, allowing the fluid to flow into the nasal cavity and exit through the opposite nostril or the mouth.
   • Repeat once or twice, collecting expelled fluid in a sterile container for analysis if required.

6. Monitor and recover

   • Observe respiratory rate and effort throughout the procedure.
   • After the final flush, gently wipe excess fluid from the snout with sterile gauze.
   • Discontinue anesthesia, place the rat in a recovery cage with a heat source, and watch until normal posture and gait resume.

7. Post‑procedure care

   • Provide fresh water and food immediately.
   • Check for epistaxis, nasal discharge, or signs of distress over the next 24 hours.
   • Record volume of saline used, amount recovered, and any abnormalities observed.

Safety considerations

• Use sterile techniques to prevent infection.
• Do not exceed 0.3 mL per nostril; larger volumes risk aspiration.
• Maintain body temperature; hypothermia impairs recovery.
• If the animal exhibits prolonged apnea or severe bleeding, terminate the procedure and seek veterinary assistance.

By adhering to these protocols, nasal irrigation can be performed reliably, yielding reproducible samples while minimizing trauma to the rat’s nasal mucosa.