1. Aseptic Technique, Surgical Support and Anesthesia
LAT Chapter 11

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3. Introduction
Many minor procedures use aseptic technique in a clean environment, such as a research laboratory.
Other procedures require a dedicated surgery room similar to that used for human patients.

4. Aseptic Technique Contamination = introduction of pathogenic organisms
A disinfected or sterile area = a field
disinfecting the field with chemical solution + manipulating sterile instruments to avoid touching contaminated surfaces
field = surgery site and adjacent areas, surgery table, area where instruments will be placed or inside of laminar flow hood
requires specialized knowledge and careful attention to detail
To prevent contamination, so healing => without infection.
Initial procedures:
preparation of surgical team, operating room, instruments, patient
During procedures:
Contact of a sterile surface with other surfaces avoided.
Like a chain, only as strong as its weakest link.

5. A Disinfected or Sterile Area

6. A Disinfected or Sterile Area

7. A Disinfected or Sterile Area

8. A Disinfected or Sterile Area

9. Aseptic Technique (continued)
Required for all vertebrate animals which are to recover.
Survival surgery on the smaller laboratory animals performed in a sanitized lab area, with appropriate aseptic technique.
A dedicated surgery required for non-rodent mammals.
Major surgery = entering a body cavity or causing permanent post-surgical disability.
Contamination prevention procedures:
1. Cleansing and disinfection of operating room
2. Preparation of incision site and draping the animal
3. Aseptic preparation of the surgical team
4. Sterilization of surgical instruments and materials
Prevention also includes responsibility of surgeon.
gentle handling of tissue and proper suturing technique

10. Aseptic Technique (continued)
Preparation of the incision site and draping the animal.

11. Maintaining Sterility
Other precautions for maintaining a sterile field are:
1. Never turn backs on a sterile surface.
2. An unsterile area not touched or leaned over.
3. Sterile instruments never be below the edge of the surgical table.
4. Arms and hands remain above the waist and below the shoulder.
5. Lift up materials, do not drag over edges of containers.
6. Keep all sterile surfaces dry.
7. Avoid excessive movement during surgery.
8. Avoid shaking of gowns, towels, drapes, and other materials.
9. Keep conversation to a minimum during surgery.
10. If waiting, clasp hands in front of your body above the waist.
If contamination occurs during any part of the procedure, stop and correct the situation immediately.

12. Maintaining Sterility

13. Sanitation
Sterility and Asepsis: Sterility = state in which there are no living microorganisms present. Asepsis = state in which the number of disease-producing microorganisms (pathogens) have been greatly reduced.
Antiseptics: substances that destroy or inhibit the growth of microorganisms, but do not sterilize the area, and can be used on living tissue
Disinfectants: destroy or inhibit the growth of microorganisms, but do not sterilize, usually damaging to living tissue
Contamination: the process by which something is rendered unclean or non-sterile

14. Pre-surgical Care of Patient
Special care aids the well-being of the animals and contributes to the success of the operation.
Food may be withheld before surgery (6–8 hours, depending on the species) to reduce the chance that the animal may vomit while anesthetized.
Sometimes an enema or laxative will be given, in addition to withholding food, to empty the contents of the lower intestinal tract prior to intestinal surgery.
Perform physical exam before surgery.
Specimens of blood and urine may be taken to help determine the animal’s state of health.

15. Patient Preparation Patient prep. includes the following steps:
1. Clip a broad area around site being careful not to cut the skin.
2. Scrub area with surgical soap for five min.
Start at center of the site and work outward in larger and larger circles. Every time you go back to the center, use a new piece of gauze and start again.
3. Wipe area with sterile gauze sponge, starting at the center of the site, until all the surgical scrub material is gone.
4. Some surgeons follow the scrub with 70 percent ethyl alcohol.
5. Sterile surgical drapes are placed around the incision site, only people wearing sterile surgical gloves should touch the site.
6. Particularly dirty animals require bathing prior to surgical prep.

16. Surgical Personnel Preparation
Scrubbing:
1- Don a mask and cap.
2- Scrubbing done with a surgical hand brush and soap.
3- Apply soap to hands and arms, lathering without brush.
4- Rinse - elevate hands above the level of elbows, so that rinse water runs off the elbows, not back over hands.
5- Reapply soap and scrub hands and arms with brush.
6- Scrub from hands to elbows so cleanest area is hands.
Each finger = > 10 strokes on each surface (40 strokes / finger)
Fingernails and both surfaces of hands = 20 strokes each
Each arms surface = 10 strokes
7- Rinse in warm water, allowing the water to drip from the elbows.
8- Repeat entire scrubbing procedure twice.

17. Surgical Personnel Preparation

18. Drying, Gowning & Gloving
Pick up sterile towel by 1 end using 1 hand.
Dry fingers and hand of the opposite arm, then dry arm to elbow.
Grasping opposite end of towel with dry hand, repeat.
Once towel is used on arms, don’t use on hands or fingers.
Unscrubbed assistant opens gown pack outer wrapping.
Scrubbed surgeon grasps folded gown at the shoulder.
Places the left arm into the sleeve, right arm into the sleeve.
Assistant grasps inside of gown and pull the sleeves into place.
grasps the inside of the gown and pull down to straighten the front
ties the neck and waist
assistant opens glove pack
Left pick up right glove rolled cuff, pull over the right...
Throughout gowning and gloving procedures, bare fingers should never touch any part of gown or any part of outside of gloves.

19. Gowning Principles of Surgery
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Gowning
Principles of Surgery
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20. Gowning Principles of Surgery
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Gowning
Principles of Surgery
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21. Gowning Principles of Surgery
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Gowning
Principles of Surgery
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22. Gowning Principles of Surgery
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Gowning
Principles of Surgery
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23. Gloving Principles of Surgery
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Gloving
Principles of Surgery
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24. Gloving Principles of Surgery
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Gloving
Principles of Surgery
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25. Gloving Principles of Surgery
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Gloving
Principles of Surgery
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26. Gloving Principles of Surgery
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Gloving
Principles of Surgery
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27. Gloving Principles of Surgery
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Gloving
Principles of Surgery
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28. Gloving Principles of Surgery
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Gloving
Principles of Surgery
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29. Gloving Principles of Surgery
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Gloving
Principles of Surgery
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30. Gloving Principles of Surgery
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Principles of Surgery
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31. Surgical Instruments I
Forceps: for compressing or grasping tissue. Thumb forceps and hemostats are typical forceps. Hemostats aid in compressing tissue, especially blood vessels, to stop bleeding (hemostasis).
Needle holders: hemostat-like devices that hold needles used to suture wounds closed.
Needles: permanently attached suture material = swaged-on. Tip may be blunt, tapered, sharp, cutting, or some other configuration
Scalpel handle and blades: size 10 blade most popular, 11 has a straight edge and a sharp point.15 has a very small cutting edge, used for fine, delicate surgery(e.g. eye). 20 is similar to 10 but larger.

32. Surgical Instruments II
Scissors: blunt-blunt, blunt-sharp, or sharp-sharp. They may also be straight or curved. Some scissors are serrated for cutting thick bandages or cartilage.
Retractors: pull overlying tissue away from the surgical site. Hand-held retractors and self-retaining
Suture materials: thickest suture is given the number 6.
<6 = smaller diameter.
Sutures having smaller diameter indicated by 0 (“aught”) smallest suture is designated 12-0 (twelve-aught).
Synthetic = nylon, or natural = silk or gut.
Some absorbed by the body during the healing process, nylon removed after wound heals, usually in 7–10 days.
Gauze pads: sponges used for soaking up blood and other fluids from the surgical site.

33. Cleaning Surgical Instruments
Manual Cleaning:
1. Rinse instruments in cold water ASAP.
2. Open all locks and disassemble instruments.
3. Inspect each instrument, for proper function and cleanliness.
4. Scrub each instrument.
5. Rinse instruments with hot, clear water.
6. Dry thoroughly before re-packing.
Ultrasonic Cleaning: converts high frequency sound waves into mechanical vibrations.
Removes ~ 90 % of the dirt and debris but does not sterilize or eliminate the need for initial removal of blood and dirt.
Lubrication: After cleaning but before autoclaving, use only antimicrobial, water-soluble lubricants.

34. Sterilizing Surgical Materials
Chemical sterilization, “cold” sterilization, reserved for surgical instruments and other items that are heat-sensitive and can be immersed in liquid.
Glutaraldehyde requires 10 hrs to sterilize instruments.
Very irritating to tissues, rinse off thoroughly with sterile saline.
Ethylene oxide requires chamber with vent to the outside
Very toxic gas; items must “air out” for a minimum of 24 hours after procedure to prevent exposure.
Plasma vapor autoclave utilizes non-toxic hydrogen peroxide to sterilize heat-sensitive items.
Dry heat sterilization in an oven or glass bead sterilizer.
Small glass beads are super-heated in a stainless steel chamber. Instruments sterilized within 10 seconds.

35. Cleaning Surgical Instruments
Glass Bead Sterilization
Cold Sterilization

36. Autoclave Sterilization
1. Soak gowns, drapes and launder.
2. Pack materials by procedure and surgeon’s preference.
3. Don’t densely pack.
4. Pack and wrap to allow opening without contaminating.
5. Color change occurs on the indicator in the center of the pack If that location reached 121°C for 15 minutes.
6. Label packs on the outside with date sterilized.
Packs correctly wrapped remain sterile for up to six months if they’re stored properly and remain dry and sealed.
Wetness destroys the effectiveness of the wrapper as a contamination barrier.

37. Autoclave Sterilization

38. Anesthesia
Local - Xylocaine (Lidocaine®) and bupivicaine (Marcaine®) injection examples
Topical liquids, sprays, ointments, or creams. Proparacaine (Ophthaine®), anesthetic eye drops
General injection = barbiturates (thiopental and pentobarbital) and ketamine.
Ketamine used to immobilize nonhuman primates
Poor analgesia and muscle relaxation, combined with analgesic
Anesthesia can be maintained in small rodents using a plastic syringe case as a nose cone.
Use under a certified fume hood that prevents the breathing of anesthetic gas by the person doing the procedure.
Gas anesthetics include halothane and isoflurane. Isoflurane produces rapid anesthesia and rapid recovery, and is often used in short procedures such as blood collection in rodents.

39. Anesthesia

40. Monitoring Anesthetized Patient
Vital signs - color of mucous membranes,capillary refill time, heart, pulse, respiratory rate and respiratory depth
Color of the foot pads (perfusion) used as an indicator of adequate blood circulation.
BP, EKG or ECG & blood gas
Frequent measurement of body temp.
General anesthetics can cause hypothermia.
Place on warm surface to prevent hypothermia.
Monitor to determine that animal is adequately anesthetized.
Too deep = close to death, insufficient = feeling pain.
If the animal withdraws the foot when it is pinched, then the surgery or painful procedure must be delayed until proper anesthesia is achieved.

41. Post-surgical Care of Patient
If still unconscious, turn from side to side frequently to prevent blood pooling in tissues of the down side.
Waking animals => involuntary and uncontrolled motions.
Place by itself in a recovery cage, food and water bowls removed.
Be aware behavior during recovering is not like conscious animal.
Be on the alert for complications that endanger life or well-being.
It is crucial that all medications be given in the correct dose and at the designated time intervals.
Keep veterinarian aware of how treatments are progressing. Veterinarian may decide to change the treatment. Technicians should not make these decisions.

42. Post-surgical Care of Patient

43. Assessing Pain & Distress
Pain perception results from stimulation of specialized nerve endings in the tissues.
Impulses from these nerve endings reach the cerebral cortex through specific nerve pathways.
Pain sensation => withdraw from noxious stimuli => protective.
Local anesthesia, nerve pathways blocked, no pain perceived.
General anesthesia, loss of consciousness, pain perception in cerebral cortex not functioning.
Stress from physiologic, psychologic, environmental or physical factors which alter normal state of homeostasis.
distress => physiological changes, difficult to observe
Acute = short and often severe / Chronic = longer time
Pain to humans is assumed pain to other species.

44. Acute Pain Guarding Crying Self-mutilation Restlessness Sweating
Panting
Tooth grinding
Recumbency
Ambulation
Abnormal postures

45. Chronic Pain 1. Limping or carrying a limb
2. Licking or rubbing an area of the body
3. Reluctance to rise and move
4. Loss of appetite
5. Change in temperament or behavior toward handlers
6. Change in bowel and/or urinary activity
7. A lack of self-grooming
analgesic drugs - acetaminophen (Tylenol®) buprenorphine and the non-steroidal anti-inflammatory drugs (NSAID) like aspirin and ibuprofen.
Analgesic reduces pain sensation. Tranquilizer diminishes anxiety.
The most important component of pain or distress control is ability of technician to recognize and assess abnormal behavior.

47. Additional Reading
1. Flecknell, P.A. Laboratory Animal Anesthesia, 2nd Ed. Academic Press, San Diego, CA, 1996.
2. Knecht, C.D. et al. Fundamental Techniques in Veterinary Surgery, 3rd Ed. W.B. Saunders, Philadelphia, PA, 1987.
3. Short, C.E., ed. Principles and Practice of Veterinary Anesthesia. Williams and Wilkins, Baltimore, MA, 1987.
4. Recognition and Alleviation of Pain and Distress in Laboratory Animals. National Academy Press, Washington, D.C., 1992.