Standard Operating Procedure

Transcription

1 Animal Care and Use Program Standard Operating Procedure Title: Standard Surgical Practices for Rodent Recovery Surgery SOP NO: AC-G004 Supersedes Version: L1 & L2 Effective Date: August 27, 2010 Choose One: Psychology Biology Animal Care Facility ACC APPROVING SIGNATURES & DATES INDICATE NA IF NOT APPLICABLE Position Signature Date ACC Chair ACC Coordinator Animal Facility Manager Researcher Veterinarian Other: Director, Neuroscience N/A N/A Purpose The preparation of the animal, the preparation of the surgeon, and the general techniques followed when performing rodent surgery are critical to the outcome of the operation and the experimental data that are being collected. The goal of aseptic technique is not necessarily set to decrease the rate of mortality associated with surgery but more importantly to minimize the untoward, unplanned alteration of physiological parameters or behavior due to post-operative infections often, sub-clinical. Indeed the effects of microbial contamination are usually not expressed clinically. However, the sub-clinical effects on the immune system, blood biochemistry, wound histology, etc, are well documented. Standardized procedures are also necessary to minimize the variability of data due to extraneous variables. The importance of this aspect of animal care is underscored by the presence of legislation in the United States and the Guidelines of the Canadian Council on Animal Care (CCAC) which both require that recovery surgery in rodents be performed using aseptic technique. AC-G004 Standard Surgical Practices for Rodent Recovery Surgery Page 1

2 The purpose of this SOP is to detail the standard practices for experimental surgery in order to facilitate the acquisition of repeatable, quality data, and at the same time be in compliance with CCAC guidelines. Responsibilities These procedures apply to all rodent surgeries being performed at Carleton University. Minor Surgery: A surgical procedure that does not result in the removal of or alteration to a functionally significant amount of tissue. Minor surgeries typically last for less than 30 minutes. In addition, animals intended to be euthanized within 24 hours of surgery are considered to be in this category when it comes to determining the level of surgical cleanliness. Major Surgery: A surgical procedure in which there is direct visual access to a major body cavity (i.e. cranium, spinal canal, thorax, abdomen) and/or exposure of a major vascular, muscular, neural, lymphatic or glandular structure and/or the removal of or alteration to a functionally significant amount of tissue. Any surgical procedure lasting longer than 30 minutes is also considered a major surgery. Materials Designated surgical suite Anesthetic scavenging system for inhalants Clippers Surgical tape Antibacterial soap, alcohol wash Draping (either cloth or disposable) Autoclave; sterilized surgical pack Syringes Sterile fluids Heating pads Disposable mask, gloves, & hair net Dedicated surgery gown (freshly laundered but not sterilized) PROCEDURES 1. Facilities 1.1 Surgical procedures are normally performed in the dedicated surgery room 276. Other rooms may be used as long as they have the approval of the ACC and meet the following criteria; room is located away from general human traffic, the area can be easily disinfected and contains only equipment necessary for the surgical procedures and experimental recordings, the surgical area is clean and clutter-free at all times, anesthetic scavenging systems are available for inhalant anesthetics, the room is held under positive pressure ventilation, a good bright light source is available, equipment for monitoring animals during surgery is available, and separate areas, or preferably separate rooms, are available for prepping and recovering animals. 2. Pre-operative Preparation of the Animal 2.1 Animals shipped from outside suppliers are acclimatized for a minimum of 5 days prior to surgery. AC-G004 Standard Surgical Practices for Rodent Recovery Surgery Page 2

3 2.2 Animals are examined to confirm they are clinically healthy. i.e. they are in good body condition and exhibiting normal behavior. 2.3 Animals are weighed and the weights are recorded. This information is important for accurately determining drug dosages and as a baseline for health monitoring. 2.4 Fasting is not normally required since rodents cannot regurgitate. Their high metabolic rate also makes them susceptible to hypoglycemia if fasted. Thirdly, rodents are coprophagic, so it is actually very difficult to prevent them from eating prior to surgery. 2.4 Restricting water is not advisable at any time. 3. Anesthesia 3.1 See specific anesthetic SOP. 4. Surgical Site Preparation 4.1 The preparation of the surgical site is performed in a separate room or area within the operating room. 4.2 The hair is clipped and the site vacuumed. Adhesive tape may also be used to further rid the site of loose hair. 4.3 The skin is decontaminated by first scrubbing with an antibacterial soap. The soap is removed with an alcohol wash. Finally, the skin is coated with an antiseptic solution and allowed to dry before surgery is started. Ideally the soap and antiseptic solution which are used are of the same class of disinfectant (i.e. both chlorhexidine and both betadinebased). 4.4 The surgical station is cleaned and disinfected with 70% alcohol prior to each surgery or group of surgeries. If a circulating water-heating blanket is to be used then the pad is covered by clean disposable drape material before each surgery or group of surgeries. 4.5 The animal is then brought to the surgical station and positioned for surgery. 5. Draping 5.1 Ideally a sterile fenestrated cloth drape or commercial disposable adhesive drape (i.e. Opsite ) is placed over the incision site particularly when there is a risk of instruments or suture material contacting the animal s skin. Partially draping or complete drape removal is acceptable only if it interferes with the ability to perform specific manipulations or make critical animal observations. 5.2 An alternative is to use an appropriately-size sheet of Glad Press-N-SealTM, which has been shown to be for all intents and purposes to be sterile straight out of the commercial box. This product is advantageous because it is transparent and allows the anesthetist/surgeon to monitor respiration and any movement. 6. Surgeon Preparation and Apparel 6.1 Surgeons thoroughly wash their hands and arms with antibacterial soap just prior to surgery. AC-G004 Standard Surgical Practices for Rodent Recovery Surgery Page 3

4 6.2 For all surgeries the surgeon wears a clean, dedicated, gown with cuffed sleeves, a mask, a cap that covers their entire hair, and fresh disposable gloves. Prior to commencing surgery the hands are disinfectant via spraying with a 10% alcohol solution. 6.3 Gloves are again sprayed with 70% alcohol intra-operatively any time they are contaminated by coming into contact with an unsterile surface. 6.4 Gloves are changed between animal surgeries or after they become significantly contaminated or torn. 6.5 Exposed skin should not be observed between the gloves and the sleeves of the lab coat. For this reason cuffed sleeves and/or gloves with long sleeves should be used. 7. Instrumentation and Supplies 7.1 Major surgeries are started using autoclaved or otherwise sterilized instruments and implants. Chemically disinfected instruments are acceptable for minor surgeries. See SOP on standard rodent surgical pack preparation for further details. 7.2 Chemical sterilization is acceptable for minor procedures. A minimum contact time of 24 hours is required. The cold sterilization tray is labeled with the date the solution was prepared. Instruments are wiped with sterile gauze square and/or rinsed with sterile saline prior to contacting animal tissues. 7.3 A surgical pack may be used for up to 5 animals as long as the dirty instruments are cleaned with 70% alcohol, heated in a glass bead-sterilizer, or placed in a cold sterilizer solution between animals. Note it is important to remove any blood and tissues from the instruments prior to placing them in the bead sterilizer; otherwise the sterilizing process will generate somewhat offending odors. Prior to touching an animal, the disinfected instrument should be rinsed with sterile water and/or cooled to an appropriate temperature. 7.4 A new sterile scalpel blade is used for each animal undergoing a major surgery. 7.5 Sterile suture material and a swedged-on needle are used for suturing tissues. The size and type of suture material used is appropriate for the tissue and surgery. For example, normally a monofilament or coated suture (i.e. PDS, Monocryl, and coated Vircryl ) would be used for skin closure in order to avoid skin infections associated with the bacterial wicking action of multifilament material. Silk sutures are to be avoided because they elicit a prominent localized inflammatory reaction. 7.6 An emergency anesthetic recovery kit is available at all times. 8. General Guidelines for Maintaining Asepsis 8.1 Once the animal and surgeon are prepped for surgery, great efforts are made to avoid breaching the aseptic barrier. If an animal needs to be manipulated, it is handled through the drape or via a sterile gauze square. Similarly if non-sterile items must be handled e.g. the anesthetic vaporizer dial, writing utensils, etc, sterile gauze is also employed. 9. Intra-Operative Animal Care 9.1 Sterile ophthalmic ointment is placed in the eyes of all anesthetized rodents. Rodents are normally exophthalmic and most anesthetics oblate the blink reflex making them susceptible to corneal desiccation. AC-G004 Standard Surgical Practices for Rodent Recovery Surgery Page 4

5 9.2 Major surgeries require the use of a supplemental heating device, preferably a circulating water-heating pad. When possible core body temperatures are monitored. 10. Post-Operative Care 10.1 Animals having undergone major surgery and/or are have been anesthetized for greater than 30 minutes are administered warm sterile fluids (SC or IP) at the dose of 10 to 20 ml/kg/hour of surgery. Therefore a 300-gram rat recovering from a major surgery/anesthetic would receive at least 3 ml of fluids. A polyionic, isotonic, crystalloid solution such as Lactated Ringers, Normosol, or Plasmalyte is recommended. Saline is to be avoided due to its weak acidity and therefore tissue irritating properties All animals are observed until they have recovered before returning them to their normal room. Recovery is defined as performing purposeful movements and the ability to ambulate in a normal fashion All animals undergoing major surgery are administered analgesic drugs. See SOP on rodent analgesia for further details. Analgesia is not administered if its omission is explained in an ACC-approved protocol AC-G004 Standard Surgical Practices for Rodent Recovery Surgery Page 5