Isoflurane sop using vet equip inhalation anestheia systems
Prepared by: Laura Lee Davis, BS
Date Prepared: February 18, 2005
Objective: Vet Equip inhalation anesthesia, Isoflurane, will be used to obtain cardiac ultrasound scans with a heart rate maintained between 400 to 500 BPM as well as acquiring a constant ECG scan.
Procedure
1) Weigh each carbon filter and record on the cylinder. The carbon traps are used to capture the Isoflurane and prevent it from being released into the work area. When the weight of the cylinder increases by 50 grams they are considered saturated with Isoflurane and are discarded and replaced with a fresh carbon filter trap.
2) Make sure the valve to the clear housing unit named induction chamber is open. This means the valve will be turned the same direction as the clear tube. Make sure the valve for the tubing portion of the set up is closed. This means the valve will be turned so that the tubing and valve will be in a cross position. Tubes run from the Isoflurane Vaporizer to a Carbon Filter. There are valves that either open the tube’s circulation or close it. One tube controls the flow of Isoflurane and Oxygen to the induction chamber unit of the Isoflurane set up (this is where the animal is initially exposed to the anesthesia and becomes sedated) and another tube controls the flow of Isoflurane and Oxygen to the mask portion of the isoflurane set up, (this tubing has a nose cone attached and will be fitted to the mouse).
3) Weigh animal. Record weight.
4) Place animal into the induction chamber, (located at the top of the Isoflurane set up). This housing unit will be ventilated with Oxygen and Isoflurane. Turn the Isoflurane Vaporizer Dial on and adjust level gage to 3 %. Turn the Oxygen on and adjust the oxygen flow meter to at least 1 liter per minute (lpm). This level of Oxygen will be maintained throughout the entire scan. Wait until the mouse is very drowsy or asleep. Push the oxygen flush button for 20 – 30 seconds to evacuate all anesthesia-saturated gas from the chamber.
5) Turn the valve for the lower portion of the Isoflurane set up on (the valve will be parallel with the tubing). This provides Isoflurane to the mouse nose cone. Turn valve connected to the induction chamber to the closed position (so the valve and tube are in a cross position). This turns off the gas to the induction chamber.
6) A small table with a warm water pad covering is located next to the Isoflureane set up. Tubing connected to the Isoflurane vaporizer and Oxygen is taped to this table. The tubing has a nose cone attached as well. Remove the anesthetized mouse from the induction chamber and immediately place the animal’s muzzle into the nose cone. Turn the Isoflurane dial back to 1 %.
7) Secure mouse to the warmed table pad (38 *C) and apply depilatory. Turn Isoflurane dial to .5% until depilatory is removed.
8) Set up ECG electrodes. Using Neonatal type cloth electrodes (like Philips Medical Supplies number 13951 C) with one electrode on each of the front paws (coded white and black) and one electrode on a back leg (coded red).
9) The amount of Isoflurane may vary from .5% to .3% to maintain a pulse rate of 400 – 500 BPM (beats per minute).
10) Complete cardiac ultrasound scan.
11) Turn Isoflurane dial OFF. Turn Oxygen OFF. Turn Oxygen flow meter OFF.
12) Clean mouse of all gel and return to his original mouse box.
13) Clean and sanitize the chamber and nose cone as outlined in your procedure area cleaning protocols.
Note
The brief oxygen flush evacuations of the chamber should not awaken already anesthetized animals.
If the valve to the nose cone is open when the oxygen flush button is depressed, the resulting oxygen pressure through the nose cone may push that animal’s nose out of the nose cone. Always close the valve to the nose cone before using the oxygen flush.
