tion devices are also effective, inexpensive, and appropriate for multi-day use. A straightforward way of monitoring the adequacy of
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artificial ventilation is to measure end-tidal CO2 either continuously or at frequent intervals (Vogler, 1997). Animals are typically given an osmotically balanced fluid and metabolites, such as lactated Ringers solution with dextrose, intravenously (DiBartola, 2000; Haskins and Eisele, 1997). When data collection goes on for several days, supplementation of that solution with potassium and/or amino acids may be desirable. For shorter experiments (under 48 hours), periodic subcutaneous administration of fluid may be sufficient. In all cases, the total volume administered should be adequate to make up for what is lost through the skin and lungs and should be sufficient to maintain renal function. The role of the kidneys in maintaining pH and osmotic balance is critical, and normal renal function can be particularly important in preventing the imbalances that may occur when animals are subjected to prolonged artificial ventilation. Monitoring urine output may be helpful in some situations to ensuring adequate renal function and hydration. During long experiments, rearranging an animal’s limbs and body and massaging the large muscle masses regularly can help to prevent the edema and venous pooling that occur in the absence of muscle tone and movement. Providing regular doses of antibiotics, vitamins, and anti-inflammatory agents may help to keep an animal in a stable condition and prevent infection (NIH, 1991). Core body temperature should be monitored throughout the period of paralysis, and supplemental heat should be provided as needed with forced air or circulating water heating pads (e.g., Vogler, 1997). Evaluating the need for aseptic technique in prolonged nonsurvival experiments requires the professional judgment of the investigator, veterinarian, and IACUC case by case. In general, the need for asepsis will depend on the duration of the experiment and the extent to which it involves the exposure of tissues or body cavities. As stated in APHIS/AC Policy 3, “nonsurvival surgeries require neither aseptic techniques nor dedicated facilities if the subjects are not anesthetized long enough to show evidence of infection.” Any procedure that lasts longer than 12 hours and involves exposed tissues or body cavities presents a significant opportunity for infection to occur, and the risk increases with the length of the procedure (Knecht et al., 1987; McCurnin and Jones, 1985). Failure to use aseptic procedures in prolonged nonsurvival experiments increases the possibility that research data will be compromised and increases the risk of premature death due to sepsis. Either of those outcomes could entail the use of additional animals, which would be inappropriate for both ethical and regulatory reasons (see U.S. Government Principle III). It would also violate the requirements of the Guide and the AWRs for the provision of adequate veterinary care. The use of aseptic procedures also helps to ensure that students learn proper surgical technique and strengthens an institution’s ability to respond to public inquiries about the use of animals in research. When a preparatory survival surgical procedure is conducted to implant devices, such as a pedestal and chamber, it should be performed under aseptic
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conditions (AWR 2.31(d)(1)(ix); NRC, 1996). Most implanted devices and their carriers can be disinfected, but it might not be possible for some sensitive or delicate equipment, such as some types of microelectrodes (for further information on this topic see “Animal Care and Use Concerns Associated with Introduction of Probes into Neural Tissue” in Chapter 4). Whenever possible, it is advisable to sterilize or disinfect devices before their insertion into neural tissue. Because a typical neuroscience laboratory contains many other items, such as recording equipment, that cannot be sterilized, the full application of aseptic technique during a prolonged nonsurvival experime