Use of Expired Materials
Expired medical materials such as drugs, fluids and sutures may not be used on any research animal who is unanesthetized or who is to recover from an anesthestic procedure. The use of such materials under these conditions constitutes inadequate veterinary care under the Animal Welfare Act.
The IACUC has established the following guidelines for the use of expired medical materials:
Preparation of the Patient
The majority of post-procedural infections are the result of contamination of the surgical site with resident or transient skin bacteria from the patient. Therefore, decontamination of the surgical site and prevention of contamination from other areas is the best means of preventing post-procedural infections.
Preparation of the Surgeon
The patient must be protected from organisms that can be carried and shed by the surgeon. These organisms reside on the surgeon's skin, hair, in the nose or mouth, or may be carried on dust particles from the floor or room surfaces. This route of contamination is minor compared to the patient's own flora, however, it is a significant source of contamination is some types of surgery such as orthopedic and central nervous system procedures.
It has been recognized that one of the greatest influences on the incidence of post-procedural infection rates is the surgeon themselves. Prolonged surgical times expose tissues to contaminants, dry out tissues and compromise the blood flow to tissues. Tissues damaged by crushing or drying, suture and other surgical implants serve as a nidus for infection. There are a number of things that surgeon's can do to prevent post-procedural infections.
Any suture that will be buried in tissues should be either absorbable or monofilament (non-absorbable braided suture is irritating and can harbor bacteria)
Sutures should be placed evenly and as close to the tissue edge as possible to prevent obstruction of blood flow- typically no more than 1 cm from the edge is necessary in large animals and 0.2 cm in small animals.
Sutures should only be tightened enough to appose the tissue edges. Any tighter will obstruct blood supply, retard wound healing and may result in dehiscence.
Skin sutures are often unnecessary. They may cause the animal to chew or scratch at the incision site. Alternatives include use of subcutaneous/intradermal closure techniques or tissue adhesive.
Wound clips typically used in rodents are not recommended. They crush large areas of tissue. The above methods or surgical staples are preferred.
Do not use toothed or crushing instruments if it is not necessary.
Hold the cut edge rather than grasping in the middle of a tissue layer.
When tying off vessels include only a minimun of surrounding tissues.
Use electrocautery or electroscalpels sparingly. They cause significant tissue necrosis.
Be aware of instrument and hand position at all times. If an instrument or hand touches something outside of the sterile field (the are delimited by the drape or the inside of the opened instrument pack) the instrument or glove should be replaced immediately.
Be gentle when handling tissues.
Use appropriate suture techniques
Ablate all "dead space" during closure. Any pockets or potential space that remains between tissue layers will fill with extracellular fluid or blood. This is an abscess waiting to happen. Tacking down tissue layers can be used. If this is not possible, use of a drain for 3 to 5 days following the procedure is recommended.
Sterile gloves should be used for all procedures. Examination gloves are not sterile. Gloves may be disinfected between surgeries with a cold sterilant for rodent and non-mammal surgeries. Large animal surgeries should be performed with a new pair of gloves for each patient.
The surgeon's hands and arms should be scrubbed for 3 minutes with a disinfectant such as povidone iodine or chlorhexidine, rinsed with water and dried prior to gloving for any large animal survival surgery. As much as 30% of the time gloves become perforated during surgery, exposing the animal's tissues directly to the surgeon's skin.
A cap, face mask, shoe covers and sterile gown must be worn for all large animal major survival surgeries.
A clean smock or lab coat is recommended when performing rodent surgeries. A hair cover and face mask will reduce the risk of gross contamination of the surgical site.
Minimizing traffic flow and conversation in the operating room significantly reduces the risk of contamination of the surgical site.
Normally, the patient's hair should be removed from the surgical site. This should done with an electric clipper or depilatory rather than a razor. Hair removal should be performed immediately prior to the surgery. Extended time between hair removal and use of razors contributes to post-procedural infections.
The patient's skin should be scrubbed with a disinfectant such as povidone iodine, alcohol or chlorhexidine. Scrubbing should start at the center of the surgical site and move to the outside in a linear or circular manner. Typically three scrubs with a disinfectant and then three with alcohol or water to remove debris are used. Often a disinfectant solution is then painted onto the surgical site and left to dry. It may not be appropriate to scrub the site of some patients. Scrubbing the skin of a fish or amphibian will remove the protective bacterial slime layer, and may actually increase the risk of infection.
A sterile surgical drape should be used whenever possible to isolate the disinfected area from surrounding areas. To be effective, a drape must fit tightly to the skin and must be impermeable to moisture. Clamps or sutures may be used to fix the drape in place. Self-adhesive drapes are also useful and are particularly recommended for use in small patients. In some cases a drape may not be practical or necessary. When a drape is not used is places extra responsibility on the surgeon to perform excellent surgical technique.
It is never acceptable to use outdated anesthetics, analgesics, or emergency drugs. Examples of acceptable materials include IV fluid solutions, non-emergency drugs (diuretics, contrast material, antibiotics), IV catheters, bandage materials, surgery gloves and suture materials.
Expired materials are only to be used on anesthetized animals in terminal studies (e.g. studies from which the animal does no awaken). Anesthesia for these terminal studies must be induced and maintained using current, non-expired drugs.
All expired materials must be clearly and individually labeled as 揈xpired--for acute use only?and are kept together in an area physically separate from all other medical materials and drugs. The area (box, shelf etc.) they are kept in must be labeled 揈xpired--for acute use only?
It is required that animals be cared for after procedures to ensure their full recovery. Post-procedural care for dogs, cats, swine, sheep and goats is provided by RAR. Post-procedural care for other animals such as small animals, nonhuman primates and in some circumstances, sheep, may be provided by the investigator under RAR supervision, or by RAR if arranged.
Projects outside of the core Minneapolis facilities must make arrangements to either have RAR provide post-op care service if practical or do the care themselves under guidance and oversight from RAR. In either case, the principal investigator should budget accordingly when planning the project. Post-operative care is not included in routine husbandry procedures or the per diem fees.
Post-procedural care includes the following:
1. Monitoring anesthetic recovery
Someone must be present with any animal recovering from anesthesia until that animal is able to hold itself in a sternal position (on its chest, able to hold its head up). This includes rodents and rabbits
Endotracheal tubes should be kept in place as long as possible; they must be removed when the animal begins to chew or swallow
Ability of animal to maintain normal physiology such as body temperature and fluid balance should be assessed.
2. Monitoring post-procedural complications
3. Maintaining records of care given. These records must include a daily assessment and treatments given. Other items that could be included in the record are anesthetic agents and time administered, intra-operative assessments and recovery observations. Post-operative records are required by the USDA on all animals except rats and mice, and must be readily available for review. Records on rats and mice may be somewhat abbreviated, and can be included as part of research data collected, but should also be available for review. For more information, contact RAR at 4-9100.
Provide analgesia for any procedures with potential for pain or distress
Administer antibiotics to prevent post-procedural infections
Monitor incisions for swelling, exudate, pain or dehiscence
Monitor catheters & devices
Monitor for procedure-related complications such as organ failure, thrombosis, ischemia