Beth Perritt / ST5 Anaesthetics Trainee, Mersey UK
Dr Beth Perritt is no self-declared animal person, and is usually found giving straightforward anaesthetics in Merseyside. However, not to be outdone by the number of unusual case reports that are increasingly published online, she tells Adventure Medic about her most bizarre encounter within her training. Who needs to spend their day in the operating theatre, when you can have a little adventure at the local zoo? This time, no kids in tow.
An unlikely patient
When pondering what to put on my UCAS form, veterinary medicine had not been even a passing consideration. Although I regularly take my children to the zoo, I have never successfully kept pets, and so it was with a sense of slight bewilderment that I found myself standing, with my consultant, outside the orangutans’ enclosure at Blackpool Zoo. We were waiting for sedation to take effect on a thirty-year-old female patient – one quite unlike any I had anaesthetised before.
The Bornean orangutan, Vicky, had been unwell for some time, suffering from chronic sinusitis and air sacculitis. Upper respiratory tract disease is a common cause of morbidity and mortality in captive orangutans and is often manifested as sinusitis and air sacculitis.1 The air sacs are an anatomical feature of primates such as orangutans, and arise from anterior laryngeal diverticula. They extend from the larynx through the neck, often into the axillae and cheeks. They have a variety of functions: deepening and increasing the volume of voice; providing cushioning to the head; stimulating a mate; communicating over long distances; and displaying aggressive behaviour.2 Infection of the air sacs is well documented in primates, and can vary from a mild subclinical infection to a potentially life-threatening syndrome when complicated by aspiration pneumonia, thromboembolism, and septicaemia.3 Although the cause of air sacculitis is not fully understood, it is thought that a primary infection of the upper airways leads to continuous drainage of exudates into the air sacs – leading to secondary infection.
The management of air sacculitis can take both medical and surgical approaches. Surgical Management for animals with severe infection includes functional endoscopic sinus surgery (FESS). The anatomy of a human and orangutan are similar, although the orangutan doesn’t have frontal and ethmoid sinuses, and their bones are much harder. As there is relatively limited experience with such surgery in primates, the vets sought help from a human ENT surgeon, Mr. Javed Tahery. Mr. Tahery had operated on Vicky a year previously, but unfortunately, her symptoms had recurred, necessitating his input once again. Further surgical intervention includes marsupialisation of the air sacs (the creation of a stoma to allow continuous drainage and help with resolution of infection).4
As anaesthetists, our involvement with Vicky was helpful in two respects – firstly, it allowed the vets to operate on her air sacs without having to concurrently provide anaesthesia, as vets would often do. Also, Vicky is an elderly orangutan. Arguably, as human anaesthetists we have greater experience with ‘little old ladies’ – the need for cautious anaesthesia, careful management of anaesthetic depth and treatment of potential haemodynamic instability was vital to ensure the best post-operative outcome for the patient.
How to knock out an ape
The day started with a thorough team brief. As with the WHO surgical safety checklist, introductions were made and a clear plan for the surgery explained. It was, however, the first brief I had been involved in where the safety of the team had to be so expressly discussed – we were warned that if Vicky were to move or wake unexpectedly, we were to leave the theatre, without delay, no questions asked… Clearly, there were considerable differences in many aspects of our anaesthetic technique. The keepers had trained Vicky to present her shoulder towards them in return for a treat. This allowed them to administer an intramuscular injection of ketamine/medetomidine. Following further boluses, she was carried out of her enclosure onto a wooden table covered with straw and, once adequately anaesthetised using isoflurane in oxygen, she was intubated. The laryngoscopic view was similar to that of a human – although the epiglottis was floppy, and the larynx a long way down with a generally darker view.
The transfer to theatre was a little more lengthy and complicated than we are used to: Vicky was carried into a horsebox with no IV access or monitoring (other than clinical observation and movement of the reservoir bag), and bound with restraints – generally frowned upon in standard human anaesthesia. On arrival into theatre she was positioned on the table, and IV access was secured while we were able to establish ECG, NIBP and SpO2 monitoring. At this point I started to feel more in my comfort zone, especially once Vicky was covered with the drapes. She could have been any extremely hairy human patient.
Once fully monitored and stable, Mr. Tahery was able to start the FESS. The case proceeded initially uneventfully, and I assumed the role of the anaesthetic registrar, administering fluid, treating hypotension with increments of ephedrine and diligently completing the anaesthetic chart. It was only when our depth of anaesthesia monitor – Vicky’s zoo keeper – would tell us that Vicky’s grip was tightening, that we were reminded of the fact that there was a wild animal under the drapes.
After the FESS was completed, the zoo vets Karen Archer and Andrew Moore started with the marsupialisation of the air sacs. During this procedure, they suture the air sac open with the aim of improving drainage. The existing congestion was washed out, and the volume and consistency of the pus was seriously impressive (see picture above): I was somewhat surprised that it only grew Strep. pneumoniae and E. coli.
At one point, Vicky moved. We had been reducing her depth of anaesthesia to improve spontaneous ventilation, as by this point we were now over two hours into the anaesthetic. However, movement was not desirable! I promptly left as instructed, leaving my consultant armed with supplemental propofol as the keepers locked the doors. Vicky was, however, safely subdued and we were able to continue without further unexpected interventions.
This was the first time that both procedures have been carried out at the same time. The combined procedure time was four hours, and by the end we were keen to wake Vicky as soon as possible – she had experienced some transient instability and we were anxious to wake and assess, as you would be with any patient. Once again transported in the back of the horsebox, Vicky was transferred back to her enclosure for recovery. This involved propping her up in the corner of a cage adjacent to her enclosure, with a rope tied around the tube. The interesting thing about orangutans is their instinct to climb – you don’t see many elderly ladies wake up in recovery and start climbing the walls (or do you?) but this is what Vicky tried to do straight away. We were pleased to see that within a matter of minutes she was becoming increasingly alert, moving around the small enclosure well.
Vicky was back with her daughters, Summer and Cherie, and the male of the group Ramon, less than 24 hours post-operatively, and is doing well. She does still have a mild nasal discharge, but it is significantly better than prior to surgery. The masupialisation is still open and draining, and despite her geriatric years, her recovery from our slightly unusual intervention seems to be complete.
What did I learn?
At the very least, next time I’m at the zoo I’ll be looking at the orangutans with more interest and respect than before. There are so many opportunities within anaesthesia to do something different, and this was just one of them. The teamwork witnessed was impressive, with a clear safety briefing, and a group of experienced people working towards a common goal. As crazy as it sounds, this experience and case highlighted quite how transferrable our skills as medics can be; so much of what I would have applied to a little (if feisty) old lady could still be put into action. Not many people will be able to discuss the merits and risks of cannulating and intubating apes at their next formal assessment – this could become an unlikely ‘unique selling point’ at interview…
References
- Zimmermann N et al. Upper respiratory tract disease in captive orangutans (Pongo sp.): prevalence in 20 European zoos and predisposing factors.” Journal of medical primatology (2011): 365-375.
- Kumar S et al. Pathology of spontaneous air sacculitis in 37 baboons and seven chimpanzees and a brief review of the literature. Journal of medical primatology (2012): 266-277.
- Miller ER, Fowler EM (Eds.) Fowler’s zoo and wild animal medicine. Vol 8. Elsevier Health Sciences: London, 2014.
- Hill LR, Lee DR, Keeling ME. Surgical technique for ambulatory management of airsacculitis in a chimpanzee (Pan troglodytes). Comparative medicine (2001): 80-84.
Karen Archer and Andrew Moore are veterinary surgeons who work at the Oakhill Veterinary Centre in Preston; find out more about them on their team page. Many thanks to Karen, Andrew, the team at Blackpool Zoo and my anaesthetic consultant Dr Paul Jameson for this unusual opportunity!
Visit the Blackpool Zoo’s Orangutan Homepage and read about The Orangutan Foundation, for more information on their conservation program and how to volunteer & get involved.
Photos: Blackpool Zoo
