Protocol for the Abdominal Implantation of Satellite and Conventional
Transmitters into Birds
USGS, BIOLOGICAL RESOURCES DIVISION MODIFICATION DATE: January 10, 2001
ALASKA SCIENCE CENTER - BIOLOGICAL SCIENCE OFFICE
1011 EAST TUDOR ROAD IACUC APPROVAL DATE:________________________
ANCHORAGE, ALASKA 99503
PROCEDURE TITLE: Surgical implantation of transmitters in the abdomens of birds.
SCOPE: This protocol
applies to the intra-abdominal surgical implantation of either satellite or
conventional radio transmitters in both waterfowl and sea birds.
PRINCIPLE: Diving birds
have been a notoriously difficult group of birds to which to attach
instrumentation, especially transmitters. Harness and nasal-mounted
transmitters have caused alterations in behavior, weight loss, and feather
destruction (c.i.f.: USFWS Canvasback Telemetry Workshop, held at Patuxent WRC
on 24-25 February, 1987; unpubl.). The surgical procedure is adapted from that
described by Korschgen et al. 1984, and is more fully described in Korschgen,
et al. (1996). Petersen, et al. (1996) used the technique to follow the
movements of spectacled eiders in the Bering Sea. VHF radios implanted with this technique into harlequin ducks (Histrionicus
histrionicus) did not affect over-winter survival and could be used to
monitor survival of this species (Esler et al. 2000a). However, both implanted ducks and those that
were captured and handled but not implanted suffered short-term loss of body
mass that was more pronounced in implanted birds (Esler et al 2000b). Body masses were recovered sometime before
recapture a year later. Mortality
during surgery and recovery and in the first 14 days after release should be
less than 1.5% when these techniques are followed (Mulcahy et al. 1999).
PROCEDURES:
1. Three people are preferred for the procedure: a surgeon, an anesthetist and a person who positions the bird and assists with the passage of the percutaneous antenna.
2. Standard aseptic surgical technique will be practiced. The surgeon will wear sterile gloves and a surgical mask. The surgical site will be prepared as for any surgical procedure, including plucking feathers, skin disinfection (using povidone iodine or chlorhexidine) and the use of a sterile drape.
3. When possible, the transmitters should be gas-sterilized in suitable packaging permeable to gas but not to bacteria. Gas sterilized transmitters should be allowed to outgas for a period of 12 hours before their use. When gas sterilization is not possible, transmitters may be disinfected in a solution of 0.13% (Zephiran̉) or 1:8 v/v chlorhexidine diacetate (Nolvasan̉) in water for 12 hours. The potential adverse effects of the disinfectants on transmitter coatings should be tested for in advance of use.
4. Surgical instruments should be sterilized in an autoclave with a minimum of two layers of packaging and stored in a dry place. If absolutely necessary, instruments may be disinfected in the field, in the same manner described for the transmitters, above.
5. Position the bird on the surgical table in dorsal recumbancy with the legs extended and the wings folded. An insulated (bubble-wrap or foam pad) cover for the surgical table should be used to retard heat loss. A circulating warm water pad should be used when possible. Because regurgitation of crop contents is a frequent problem, birds should be intubated. Birds should be placed on an elevated platform with a sloped ramp, positioning the bird’s head on the ramp so that it is lower than the body.
6. A single intramuscular dose of ketoprofen at 4 mg/kg is given during or immediately following induction for presumptive post-operative analgesia.
7. Isoflurane gas anesthetic is administered to the bird by face mask on a non-rebreathing circuit. Induction is at 4-5% isoflurane; maintenance is at 1-2% isoflurane in oxygen or at a level found necessary for a given species and a given individual. Maintenance concentrations of isoflurane may vary depending on the individual bird and environmental variables. The bird is intubated with a cuffless tube or with a cuffed tube without inflating the cuff. A protective ointment may be used in the eyes to prevent drying of the cornea. Once the abdominal air sacs of a bird are opened, respiration can occur partially through the surgical incision, which may require a higher setting on the vaporizer to compensate. Once the incision is closed, the vaporizer setting may need to be reduced. If oxygen is not available, compressed air (optimum: >50 psi; minimum: 30 psi) can be used to drive the vaporizer.
8. An alternative protocol is the intravenous administration of propofol in combination with a local anesthetic block at the incision site (Machin and Caulkett 1998, 2000). Propofol does not contain a preservative and supports bacterial growth, so every effort must be made to maintain the stock vial in a sterile state. Only new needles may be placed into a vial of propofol. Opened vials of propofol should be kept refrigerated if possible. Open vials should be discarded if aseptic technique is broken, or within 24 hours of being opened. A 25 gauge 3/8 in. butterfly catheter is placed into the tibiotarsal vein (alternatively, a 21 gauge, 1 in. butterfly catheter may be placed into the jugular vein. The catheter is taped in place. Induction of anesthesia is accomplished by delivering a slow bolus (over 1 min) of 10 mg/kg propofol. Additional boluses of 1-2 mg may be given to attain induction and to maintain a surgical plane of anesthesia. All birds must be intubated, and ventilated with a bird AMBU bag. The incision site and the antenna exit site are infiltrated with 2 mg/kg of a 0.5% solution of bupivicaine, or of lidocaine. Mortality of male eiders (spectacled and king) has occurred with propofol used as an anesthetic. Until further information is obtained, propofol should be used only with the greatest caution in male eiders.
9. Anesthesia is monitored by use of a respiratory or cardiac monitor, or both. A pulse oximeter or Doppler ultrasound are the preferred monitor. An ECG is highly recommended. Manual palpation of a tibial or brachial arterial pulse can also be used, but is less preferred to an attached continuous electronic monitor.
10. Body temperature is monitored with an electronic thermometer with the sensor placed either well into the esophagus or in the cloaca. The desired temperature range during anesthesia and surgery is 100º to 105º F. The bird should be warmed or cooled to maintain this range. Additional heat can be supplied to a cold bird by placing bags of warm water on the ventral surfaces of the wings or, ideally, by the use of a radiant heat source located above the bird. Body temperature can be reduced by removal of external heat sources and by wiping the feet with alcohol or cold water.
11. Respiration is monitored and mechanically supported when spontaneous breathing is less than one breath per minute. A minimum of two ventilations per min are made with a bird AMBU bag or with the ventilation bag. Avoid excess assisted ventilation to avoid delaying a return to spontaneous breathing.
12. The surgical site is between the distal end of the keel and the conjuncture of the distal ends of the pubic bones, palpated through the abdominal wall. The feathers are plucked from the site. An area 1 cm on either side of the incision site should be plucked free of feathers. The feathers around the site are taped back with pieces of microporous tape. A site for the exit of the percutaneous antennae is located by palpating with a finger the intersection of the right pubis bone with the synsacrum. A small (1 cm2) area is plucked free of feathers and the feathers adjacent to the site are taped back using microporous tape. Both sites are swabbed twice with povidone-iodine or benzalkonium chloride solution. Following site preparation, a sterile gauze pad is placed over the antenna exit site to protect it. A sterile fenestrated drape is placed over the surgical site.
13. The skin is incised along the ventral midline with a No. 11 or No. 15 sterile blade. The subcutaneous layer and fat are sharp dissected. Once the muscular abdominal wall is reached, the linea alba is identified. The linea alba is seized with a forceps and lifted to permit penetration of the abdominal wall with a blade. The linea alba is then sharp dissected with blade or scissors, avoiding the viscera, to a length of about 3 cm, or a distance sufficient to pass the transmitter body.
14. Using fingers, clear a space on the right side of the abdomen, as dorsally (lateral to the ventriculus) as possible.
15. There are two methods for passing the trochar through the body wall. Maintaining a sterile surgical site, the surgeon lifts the drape, folding it over the abdominal incision. The assistant positions the legs of the bird to permit access to the antenna exit site. The surgeon palpates the site with the right hand and, if necessary, nicks the skin with a blade at the most dorsal position nearest to the intersection of the pubis and synsacrum. Then the surgeon uses a blunt stainless steel trochar to penetrate the abdominal wall, protecting the viscera with his left index finger placed inside the bird. The trochar is drawn inside the bird full length and the assistant holds the exterior end of the trochar in order to maintain its position and to keep the pointed end of the trochar visible through the incision. The surgeon returns the drape to its proper position and then changes gloves. The surgeon removes the transmitter from the sterilizing solution or the envelope. If a liquid disinfectant has been used, an assistant rinses the sterilizing solution from the transmitter using at least 10 cc of sterile saline, while the surgeon holds the transmitter away from the incision. Alternatively, the trochar may be passed through the drape into the antenna exit site. The drape is then pulled over the hub of the trochar, leaving the trochar entirely below the drape. The method eliminates the need for glove changes.
16. The surgeon then removes the transmitter from the disinfecting solution or from the envelope. If a liquid disinfectant was used, an assistant rinses the solution off of the transmitter and antenna collar using at least 100 of sterile saline sprayed from a syringe, while the surgeon holds the transmitter away from the incision.
17. The surgeon then places the antenna into the lowest hole in the trochar. With braided wire antennas, such as those used with satellite transmitters, only the end of the antenna can be jammed into the trochar. The surgeon inserts a finger into the incision, along the path of the trochar, to protect the viscera as the trochar is withdrawn. As the surgeon guides the antenna into the incision, the assistant slowly withdraws the trochar until the end of the antenna can be seen or felt. Frequently there is a detente as the antenna meets and penetrates the body wall.
18. As the assistant continues to withdraw the antenna, the surgeon guides the transmitter through the incision, which may need to be slightly stretched to pass the transmitter. The antenna is withdrawn until the collar meets the body wall. The transmitter must be positioned on its narrowest edge and to fit snugly along the dorsal wall, in a "notch" that can be palpated by the surgeon.
19. The assistant maintains the position of the transmitter for the remainder of the surgery by keeping a firm grip on the antenna adjacent to the body wall, to prevent rotation of the transmitter if the bird moves.
20. The surgical incision is closed in two layers using 3-0 braided absorbable sutures on a cutting needle. The linea alba is closed using a simple continuous pattern and the skin is closed using either a simple continuous or simple interrupted pattern.
21. A single simple interrupted suture is used to hold the antenna collar to the body wall. The surgeon can reposition the transmitter body by moving the antenna. The surgeon should then place tension on the antenna to allow passage of the needle through the antenna collar. When placing the suture, the needle must penetrate the dacron or plastic of the collar to assure stability. To determine that the collar has been penetrated, the antenna can be moved in and out to see if the needle moves with it.
22. The drape is removed and the vaporizer is turned to zero. Oxygen supplementation should continue until the bird recovers. Additional procedures such as obtaining a blood sample or banding may be done during this period. The bird should be kept warm by holding it wrapped in a towel until it is fully recovered. If dehydration is a problem, subcutaneous fluids can be administered.
23. Following recovery, the bird should be placed in a cage or kennel for at least one hour prior to release. Birds should be released only when they are alert, able to maintain head and body position, and react to human handling. Birds that do not respond should be carefully inspected and supportive care (heat source, gastric intubation of water and electrolytes, etc.).
REFERENCES:
Esler, D., J. A. Schmutz, R. L. Jarvis, and D. M. Mulcahy. 2000a. Winter survival of adult female harlequin ducks in relation to history of contamination by the Exxon Valdez oil spill. Journal of Wildlife Management 64(3):839-847.
Esler, D., D. M. Mulcahy, and R. L. Jarvis. 2000b. Testing assumptions for unbiased estimation of survival of radiomarked harlequin ducks. Journal of Wildlife Management 64(3):591-598.
Korschgen, C. E., S. J. Maxson, and V. B. Kuechle. 1984. Evaluation of implanted radio transmitters in ducks. J. Wildl. Manage. 48:982-987.
Korschgen, C. E., K. P. Kenow, A. Gendron-Fitzpatrick, W. L. Green, and F. J. Dein. 1996. Implanting intra-abdominal radiotransmitters with external whip antennas in ducks. J. Wildl. Manage. 60(1):132-137.
Machin, K. L., N. A. Caulkett. 1998. Investigation of injectable anesthetic agents in mallard ducks (Anas platyrhynchos): a descriptive study. J. Avian Med. Surg. 12 (4): 255-262.
Machin, K. L., N. A. Caulkett. 2000. Evaluation of isoflurane and propofol anesthesia for intraabdominal transmitter placement in nesting female canvasback ducks. J. Wildl. Dis. 36(2):324-334.
Mulcahy, D. M. and D. Esler. 1999. Surgical and immediate post-release mortality of harlequin ducks (Histrionicus histrionicus) implanted with abdominal radio transmitters with percutaneous antennas. J. Zoo Wildl. Med. 30(3):397-401.
Petersen, M. R., D. C. Douglas, and D. M. Mulcahy. 1995. Use of implanted satellite transmitters to locate spectacled eiders at-sea. Condor 97:276-278.
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