How do you give a rat anesthesia? - briefly
Provide anesthesia to a rat by exposing it to a precisely controlled isoflurane concentration (1–3 % in oxygen) within a sealed induction chamber, monitoring respiratory rate and loss of righting reflex. Alternatively, inject a weight‑based mixture of ketamine (80 mg/kg) and xylazine (10 mg/kg) intraperitoneally, then verify absence of pedal and corneal reflexes before any procedure.
How do you give a rat anesthesia? - in detail
Administering anesthesia to a laboratory rat requires careful preparation, precise dosing, and continuous monitoring. Follow these steps to achieve a reliable and humane anesthetic plane.
Begin by selecting an appropriate anesthetic regimen. Common choices include inhalational agents such as isoflurane and injectable combinations like ketamine‑xylazine. The selection depends on the duration of the procedure, required depth of anesthesia, and the need for rapid recovery.
Preparation
- Verify the health status of the animal; exclude individuals with respiratory or cardiovascular compromise.
- Fast the rat for 2–4 hours before surgery if a full‑body procedure is planned; allow water ad libitum.
- Calibrate the anesthesia delivery system (vaporizers, syringes) and confirm the accuracy of the dosing calculator.
- Gather monitoring equipment: pulse oximeter, rectal thermometer, capnograph (if available), and a warming pad.
Induction with inhalational agent
- Place the rat in a transparent induction chamber.
- Introduce isoflurane at 3–5 % in oxygen (1 L min⁻¹) until loss of righting reflex, typically 30–60 seconds.
- Transfer the animal to a nose‑cone or mask, reduce isoflurane to 1–2 % for maintenance.
- Adjust the flow to maintain a stable respiratory rate (70–120 breaths min⁻¹) and heart rate (350–500 bpm).
Injection protocol (ketamine‑xylazine)
- Calculate dose based on body weight (average adult rat 250–300 g):
- Ketamine: 80–100 mg kg⁻¹
- Xylazine: 5–10 mg kg⁻¹
- Mix the drugs in sterile saline, draw into a 1‑ml syringe.
- Administer intraperitoneally using a 25‑gauge needle; inject slowly to avoid abdominal trauma.
- Observe for loss of pedal reflex (approximately 5 minutes post‑injection). Maintain depth by supplemental doses (¼ of the initial volume) if necessary.
Monitoring during anesthesia
- Record respiratory rate, heart rate, and body temperature every 5 minutes.
- Maintain core temperature at 37 ± 0.5 °C with a heating pad.
- Adjust anesthetic concentration or provide supplemental analgesia (e.g., buprenorphine 0.05 mg kg⁻¹ subcutaneously) as required.
Recovery
- Discontinue inhalational agent or cease supplemental injections.
- Place the rat in a clean recovery cage with a soft bedding substrate.
- Continue temperature support until the animal regains righting reflex and ambulation.
- Monitor for at least 30 minutes to ensure normal respiration and behavior.
Adhering to these procedures minimizes physiological stress, ensures consistent anesthetic depth, and complies with ethical standards for animal research.