AVIAN ANESTHESIA & SURGERY Kim Healy VETS 247 – Exotic Animal Medicine and Nursing Dr. Meckel Spring 2008

Anesthetic Procedures Surgical sexing –Not as commonly done now –DNA testing Abscess/Wound repair Repair bone fractures Foreign body removal Growth removals

Anesthetic Procedures Radiography Endoscopy Repair beak abnormalities –Scissor beak Reproductive problems –Egg-bound Many more

Preanesthetic Period Complete History Physical Exam Diagnostics –CBC/Chem –+/- Radiographs or Ultrasound Stabilization for critical patients Fasting: 0-2 hours prior to procedure

Premedication Rarely used –Stress from handling –Unpredictability of injectable drugs Anticholinergics (Atropine, Glycopyrrolate) –If history of bradycradia Opioids (Butorphanol) –Reversible

Induction Inhalants – preferred method Isoflurane or Sevoflurane –Iso: less cardiac s/e Benefits – Rapid induction and recovery – Rapid adjustments to anesthetic depths – Low organ toxicity

Induction Injectables –Unpredictable effects –Side effects –Extended recovery times Ketamine +/- Benzodiazepines –Long & stormy recovery Propofol –Respiratory depression –Stormy recovery

Induction Mask Commercially made Home made –Plastic bottles or syringe cases Smaller patients –Whole head inside mask

Intubation Can use mask for very short procedures Intubation provides: –Manual ventilation –Prevents aspiration Non-rebreathing system –Less than 7kg

Intubation Concentric (complete) tracheal rings –Less flexible Don’t inflate cuff of endotracheal tube Or, use uncuffed tubes –Cole Inflated cuff can cause pressure necrosis of trachea and sloughing of mucosa

Intubation

Air sac cannula –Head/beak procedures –Clearing tracheal obstruction Caudal thoracic air sac –Through lateral body wall –Typically left side – larger air sac Can be left in for several days –E-collar

Air Sac Cannulation

Local Anesthesia Example – Lidocaine Not recommended –Necessary dose higher than toxic dose, especially in smaller birds –Restraint of an awake bird is difficult

Surgical Prep Avoid heat loss! –High surface area to volume ratio = lose heat quickly Pluck only necessary feathers –Pluck in opposite direction Chlorexidine or Betadine scrub Saline –Alcohol will cause heat loss Transparent sterile drape –Retains heat –Easier to monitor patient

Transparent Drape

Monitoring Manual Auscult heart rate –Stethoscope, esophageal stethoscope Observe breathing –Can be difficult to visualize –Lungs rigid, no diaphragm –Muscular movement of ribs/sternum Relaxed when anesthetized Shivering = too light

Monitoring ECG – Heart activity –Larger birds –Smaller birds Machine that can register rapid heart rate Doppler – Blood pressure –Medial metatarsal artery –Radial artery Pulse Oximeter – Oxygen saturation –Femur, foot, toe, radius –Can be difficult to get a reading Cloacal or esophageal thermometer

Monitoring Blood Pressure

Catheterization Replace fluids lost Maintain blood pressure Blood Transfusion IV Dextrose Not often done –Difficult to monitor blood pressure –Avoid overhydration

Catheterization Intravenous (IV) –Fragile veins: long-term is difficult –Jugular, basilic, medial metatarsal veins Intraosseous (IO) –Bone –Distal ulna

Intraosseous Catheter

Anesthetized Patient a/b- et tube c- IVC d- IVF e- pulse ox

Thermal Support High surface area to volume ratio = lose heat quickly Heated surgery table Water circulating blanket Forced air blankets (Bair hugger) NO Heat lamps/heating pads – NOT RECOMMENDED! – thermal burns even on low setting

Heat Support

IPPV Intermittent Partial Pressure Ventilation –“Bagging” –Mechanical Ventilator Inflates and circulates air through air sacs 1-4 times per minute Do not exceed 15mm H2O –Overinflation, rupture of air sacs

IPPV - Bagging

Recovery Incubator –Stabilize temperature –Oxygen support Wrapped in towel Remove endotracheal tube –Chewing/swallowing, head shaking, flapping wings Feed small amount of food or few drops 50% dextrose –hypoglycemia

Incubator

Instruments & Equipment Small specialized surgical instruments Ophthalmology instruments –Delicate and precise Laser –Cauterizes for hemostasis –Shorter surgical/anesthesia times Endoscope

Equipment Optical Magnification –Binocular head sets –microscope

Suture Fine suture for thin skin 4-0 to 8-0 Tapered needle Tissue glue

Suture

Sources Cited Ballard, B., & Cheek, R. (2003). Exotic Animal Medicine for the Veterinary Technician. Iowa: Blackwell Publishing. Tully, Jr., T.N., & Mitchell, MA. (2001). A Technician’s Guide to Exotic Animal Care. Colorado: AAHA Press. Nielsen, L. (1999). Chemical Immobilization of Wild and Exotic Animals. Iowa: Iowa State University Press. Tseng, F.S., & Kaufman, G. Avian Anesthesia and Surgery. Retrieved March 15, 2008, from Tufts University Open Courseware. Web site: /5/ lecturenotes/215768http://ocw.tufts.edu/Content /5/ Gunkel, C., & Lafortune, M. (2005). Current Techniques in Avian Anesthesia. Seminars in Avian and Exotic Pet Medicine, 14,4, Retrieved March 15, 2008, from Science Direct Database. Avian Surgery: To Cut is to Cure. (2006). Exotic Pet Veterinarian. Retrieved March 15, 2008, from Exotic Animal Anesthesia, Perioperative Support, and Surgical Instrumentation. Michigan Veterinary Medical Association. Retrieved March 15, 2008, from