Adopted: February 9, 2010
Last Review Date: December 7, 2020
I. Purpose
The purpose of this policy is to protect the health of persons working with or near anesthetic gases used to sedate or euthanize animals at the 老虎机攻略. Volatile anesthetic waste gases should be minimized through training in anesthetic administration, using the smallest amount of anesthesia necessary, maintaining anesthetic equipment in proper working order, scavenging anesthetic waste gases, and monitoring worker exposure.
II. Procedure
A. Approved Inhalant Anesthetic Agents
1. Isoflurane is the only approved volatile halogenated anesthetic agents at the
老虎机攻略. Isoflurane may be used for both anesthesia and
euthanasia with proper approval from the Institutional Animal Care and Use
Committee.
2. Nitrous oxide is not approved for use in any facilities at the 老虎机攻略.
Its primary indication in veterinary medicine is as an adjunct to inhalant
anesthesia for added relaxation and analgesia. However, there are a variety of
alternative injectable sedatives and analgesics that are efficacious and do not
present health risks to personnel.
B. Anesthetic Training
1. Training to ensure the safety of animals being anesthetized and of the persons in
the area must be provided by the principal investigator (PI), Attending
Veterinarian, Laboratory Animal Resources (LAR) staff, or a trained and
experienced scientific laboratory member approved under the animal use
protocol (AUP).
2. Training should include checking the anesthetic circuit for leaks, operating
vaporizers at their lowest settings necessary for maintaining adequate anesthesia,
use of scavenging equipment, and animal monitoring.
C. Equipment Maintenance
1. Vaporizers are fully cleaned and calibrated by an authorized exchange service
center every other year. In the years between the exchange, vaporizers are
examined by a certified technician using leak and delivery accuracy testing on
site.
2. In both cases, vaporizers are marked with a sticker indicating the date of testing
or the date of next needed maintenance.
3. Maintenance is scheduled through LAR or verification provided in writing to the
Facility Manager.
D. Waste Gas Scavenging
1. When using an anesthetic vaporizer, waste gas should be scavenged actively
through a house vacuum, passively using a charcoal canister, or actively and
passively [e.g., active anesthetic evacuation system (A.E.S., Surgivet) feeding a
charcoal canister].
2. Endotracheal tubes should have cuffs to prevent leakage, and animal face
masks should fit snugly.
3. When using the open-drop method in the laboratory (e.g., a closed jar containing
gauze with anesthetic dripped on the gauze), it must be performed in a fume
hood. Care should be taken to ensure that the liquid anesthetic does not come
into direct contact with the animal.
4. In the field, use of the open-drop method requires adequate ventilation, holding
the jar at arm’s length when opening, and using a jar/container with a volume of
500-1000 ml. Care should be taken to ensure that the liquid anesthetic does not
directly contact the animal.
E. Worker Exposure Monitoring
1. In the absence of established national guidelines for isoflurane, it is our practice to
use 2 ppm as an institutional recommended exposure limit (REL). Monitoring of
personnel using badges clipped to clothing in the breathing zone has verified that
exposures are below the REL.
2. The United States Department of Labor, Occupational Safety and Health
Administration has published a document entitled "
According to this document,
"In 1997, the National Institute for Occupational Safety and Health (NIOSH) … recommended that no worker should be exposed at ceiling concentrations greater than 2 ppm of any halogenated anesthetic agent over a sampling period not to exceed one hour (NIOSH 1977). In 1989, the American Conference of Governmental Industrial Hygienists (ACGIH) assigned a threshold limit value-time-weighted average (TLV-TWA) for . . . halothane and enflurane, and are 50 ppm and 75 ppm, respectively. No NIOSH recommended exposure limits (REL) exist for the three most currently used anesthetics (isoflurane, desflurane, and sevoflurane). The levels of risk for isoflurane, desflurane, and sevoflurane have not been established. Since there are limited data, occupational exposure limits for these agents have not been determined. Therefore, until more information is available, it is prudent to attempt to minimize occupational exposure to these as with all anesthetic agents."