An 85-kg, 23-year-old, multiparous female western lowland gorilla (Gorilla gorilla gorilla) was immobilized for exploratory laparotomy to investigate a suspected abdominal abscess. Infiltrative intra-abdominal and subcutaneous abscesses were confirmed surgically, with focal peritonitis associated with cecal and colonic perforation. Typhlectomy and ileocolic anastomosis were performed, and severely infiltrated body wall was resected. For the ensuing 28 days, the animal was maintained in a hospital setting to permit surgical recovery and ongoing treatment. The animal was attended by veterinary staff (doctors and technicians) and by Bronx Zoo Mammal Department keeper and curatorial staff for direct around-the-clock observation and care.
During the initial surgical immobilization, a 5 fr x 55 cm double-lumen percutaneous intravenous catheter (PowerPICC, Bard Access Systems, Salt Lake City, UT) was placed with ultrasound guidance in the left basilic vein. This catheter was maintained for the entire four-week postoperative period through a varied and evolving set of protective measures. The left arm was immobilized with fiberglass casting material (Vetcast Plus, 3M Health Care, Neuss, Germany), while the entire length of IV line to which the animal had contact was secured and encased within either rubber or lightweight flexible metal tubing. Continuous intravenous access permitted the use of sedative and analgesic drugs to maintain the animal in a state of tranquilization, yet sufficiently functional to eat and void normally, and move within the confines of her 1.7x1.3x1.8 m hospital enclosure. Fentanyl (100–150 µg/h) and midazolam (1–1.5 mg/h) were administered as constant-rate infusions and adjusted to effect for 19 days postoperatively. Ketorolac (30 mg IV BID) and acetaminophen (1000 mg IV TID) were administered for analgesia. Antimicrobials were administered intravenously based upon culture and sensitivity results. Lorazepam (2–4 mg PO BID) was introduced on day 19 postoperatively as a replacement for IV midazolam, while fentanyl was gradually decreased from 100 µg/h to 75 µg/h CRI. However, midazolam was resumed and continued at 1–1.5 mg/h CRI on day 21 postoperatively, while fentanyl was further tapered from 75 µg/h to 25 µg/h CRI. Fentanyl and midazolam CRI were both discontinued on day 28 postoperatively, when her IV catheter was removed, and the animal was returned to her regular off-exhibit enclosure. She was maintained on oral lorazepam at 2–4 mg PO BID for 34 days, as she was gradually reintroduced to her troop. There were no complications associated with long-term maintenance of the indwelling intravenous catheter, nor of immobilization of the left arm by casting. This case demonstrates a successful means of maintaining an indwelling percutaneous intravenous catheter in the western lowland gorilla, and of promoting postoperative care and convalescence through constant chemical sedation.
The authors would like to thank the Dr. Colleen McCann and the rest of the curatorial and keeper staff of the Bronx Zoo Mammal Department for many hours spent providing overnight care and observation. We also express our gratitude to Drs. Steve Gorfine and Dan Popowich, who were invaluable in leading the surgical intervention, and to Dr. Sharif Ellozy for his placement of the indwelling intravenous catheter.