Professor Fred Mimh

Professor Fred Mihm is a critical care and regional anaesthesia specialist with an impressive array of experiences. A Professor of Anesthesiology, Perioperative and Pain Medicine at Stanford University Medical his special interests include the care of complex medical patients requiring high-risk anaesthetics and surgery. In particular Pheochromocytoma – a rare, life-threatening endocrine tumour, of which he has cared for more than 300 patients with this condition.

We are delighted to be welcoming Professor Mihm to Aotearoa in November as a keynote speaker at this year’s Aotearoa NZ Anaesthesia ASM, where he’ll be sharing his expertise across these special interests such as the Physiologic Difficult Airway, Stellate Ganglion Blockade and Perioperative management of Pheochromocytoma.

Alongside his academic pursuits, he has also volunteered his skills on numerous global health missions and in assisting with anaesthetising more than 100 animals at the San Diego and San Francisco Zoos.

Ahead of travelling to Aotearoa in November, Professor Mihm joined us for a kōrero about his other special interests. Starting right at the start, his first global health trip as a resident to San Pedro Sula, Honduras in 1978 with Plastic Surgeon Dr Donald Laub, founder of Interplast and colleague at Stanford.

“Donald initiated Interplast through a desire to do good for those in need in other countries and provide his trainees with exposure to conditions seen infrequently at home.” Values that align with Professor Mihm, who being raised in a Christian household often heard the directive ‘love your neighbour’.

This was a mandate he understood to be “lived out in tangible ways. Be ready to be generous with your time and talent and seek opportunities to do this”.

“For me, ‘my neighbour’ has always had a global connotation. Growing up surrounded by others who worked in low-resource countries to help those in need, I jumped at the opportunity to do the same.”

“In San Pedro Sula, we were based in a very small hospital and set up two OR tables in the same room. The room had one window with a fan in it that didn’t work. Every day was blistering hot and by the end of the day, the halothane was so thick you could cut the air with a knife. But the personal rewards were so compelling. Once you start doing something like this you get the bug for it.”

As luck or destiny would have it, Professor Mihm returned to the same hospital 41 years later. “It was quite special to go back to where I’d started and see how much it had changed. They’d built new facilities and there was an anaesthesia training programme with abundant opportunities for teaching, which is always an important part of these trips.”

“As a specialist in regional anaesthesia and critical care, I’ve gravitated towards orthopaedic service trips in recent years. Regional anaesthesia instruction is highly valued overseas and at these locations, anaesthesia providers are always eager to learn how to do regional blocks. I’ve also enjoyed some purely educational trips and was in Uganda earlier this year teaching at a small university anaesthesia training programme.”

Accumulating over two years across 51 trips Professor Mimh has learned some valuable lessons.

His tips for anyone undertaking a trip to work in a low-resource area:

1. Find out as much as you can about what you’re stepping into, so you’re as prepared as possible. Find out how they practise, what kind of cases they do and what supplies you might need to bring. “On one trip to Guatemala, we were operating in a clinic with no anaesthesia machine, just an oxygen cylinder. That was it. They really only did c-sections under IV ketamine. I was fortunate to know all of this before I arrived. I ended up bringing a syringe pump and chose a propofol/ketamine TIVA technique which worked well.”

2. Take duct tape. Building an ‘anaesthesia workroom’ of usable supplies duct-taped to a wall has become a signature of Professor Mihm’s trips. “Particularly when you’ve brought these supplies with you, it makes them visible. Without a workroom or Tech to help you, the wall makes it easy to see what you have and what you’re running low on. Anyone can access it quickly. In particular, the emergency supplies are placed in a specific section of the wall.”

3. Be ready to improvise. “When I was a resident, I was taught to make a MAP Mobile using the aneroid monitor from a blood pressure cuff for real-time blood pressure monitoring without any electronic equipment. We often used it back home transporting seriously ill patients from the OR to ICU, long before portable transport monitors were developed. I’ve used this in Africa when they were planning heart surgery without an arterial line, and where there was no ability to measure intra-arterial blood pressure.”

4. Be ready to learn something new. “During a trip to Vietnam focussed on hypospadias repairs, the prior year’s anaesthetist commented during our handover that they placed trans sacral epidural blocks for all of the patients. I had to look it up and it turns out the sacrum has joints that I thought were fused very early in life – they aren’t. You can go into the sacral joints between sacral S2 and 3 and insert an epidural catheter. It’s exactly the nerve root level you want for this type of surgery. I’d never done it before or since that trip, but it was just amazingly easy to learn and it was effective in every patient that we cared for.”

5. Know what’s available. “You often have to think about the basics to be sure you won’t get caught with assumptions that aren’t true where you’re working, for example, blood and oxygen. One question I always ask, especially if the surgeons want to do complex surgery is ‘Can we get blood if we need it?’ Knowing this might alter your plans or decision to do surgery.”

“The first time I went to Africa was in 1994 to Moshi Tanzania. Their primary general anaesthetic was Ether through a drawover vaporiser and manual insufflation with an Oxford Bellows, neither of which I had ever seen.” They were also operating with general anesthesia using room air! There was no oxygen available, with their oxygen concentrator broken. If a patient needed supplemental oxygen post-surgery, it wasn’t available. The latter has been true in a lot of places I’ve visited. You might be able to give some oxygen in the recovery room but sending a patient to the ward with even 1-2 LPM is something we take for granted.

The exotic animals

His other volunteering pursuit, a little closer to home, is assisting in anaesthetising all kinds of exotic animals including gorillas, giraffes, lions, tigers, penguins, chimpanzees, orangutans and elephants.

“A lot of American zoos will consult with human physicians, especially anesthesiologists. Complications related to anaesthesia are one of the common issues when anaesthetising animals and when it comes to exotic animals there’s typically only case reporting and word of mouth to investigate ahead of time in order to be prepared”.

“Vets use a lot of the same or similar drugs – ketamine, halothane, isoflurane and sevoflurane with anaesthesia machines. But they also have many veterinary drugs that we don’t use, for example the narcotic Etorphine. We used it on an elephant once.
We gave her 2 milligrams of Etorphine and that was enough to do surgery on this animal weighing 6,712 lbs [over 3,000kgs]!”

“This is one of the few times that we knew the exact weight of the animal!”

When it comes to logistics ventilation and monitoring are the biggest considerations, particularly for the larger animals like elephants and rhinos. These larger animals spontaneously breathe while lying on their side during surgery.

“You have to learn to modify equipment. Pulse oximeters don’t work on Gorillas, for example. Their skin is about 1cm thick and incredibly dark in pigment. I modified a pulse oximeter to a clip by dissecting an oximeter. By putting the LED on one side of the clip and the photodetector on the other we could clip it on an animal’s tongue.”

Safety also quickly comes to mind when you think about working with exotic and often dangerous animals.

“Part of the excitement is getting up close and observing these animals in a way you never otherwise could, but you have to juggle your personal safety and the safety of the animals.”

The trickiest times are before and after anaesthesia.

“To start with you have to guess their weight to sedate them before they’re brought to the zoo’s hospital where we can weigh them properly. Guess too little and you’re in the cage with them and you’re in trouble, or too much and there’s the risk they’re over anaesthetised and the animal is in trouble.”

“Then afterwards when you’re putting them back in the cage it’s dangerous because they’re starting to wake. Typically, they’re placed with their head near the bars of the enclosure while still intubated with a string tied to the end of the tracheal tube so you can pull the tube out when they start rousing. However, there’s always the risk of complications and what to do if they get into trouble.”

“We had an occasion with Koko the gorilla who went into respiratory arrest after getting back into her cage. She no longer had an IV and we had to decide whether it was safe to go into the cage and pull her out without giving her additional anaesthetic. In retrospect, we were right to do so, as she was down enough that there was no risk to us, but if we’d waited longer she wouldn’t have survived.”

The lions have created some of the more harrowing moments for Professor Mihm.

“To intubate a lion you have to put your arm right into their mouth and their mouth is held open because we don’t use muscle relaxants. Once after intubating one of the lions, he [the lion] started seizing quite violently and I had to hold on to the tracheal tube during the seizure so that the lion wouldn’t have an accidental extubation.

“On another visit, I was supposed to be darting a lion to sedate it. You need a side shot and having been darted by the vet another time the lion knew something was up, so it had its eyes trained on the vet. I had a good shot from the cage next door but left the safety on and the trigger made a little click. The lion spun around in an instant and roared right at me. My hair was blown back by its hot breath, it was like a hot fan. It was horrible but pretty amazing. Their roar has a very low pitch and your whole body vibrates like you’re standing next to a big base speaker.”

Koko the signing Gorilla is the most interesting animal he’s worked with.

“I was sceptical at first but the more I got to know Koko the more I started recognising some of the unique signs she was making. One time she gestured to her head wanting to know where my hat was because I’d always worn one the prior times I’d visited. She wanted me to sit close to the cage so she could see me better and I could hear her purring, they purr like kittens.”

Both his work with the animals and time volunteering in low-resource countries offer adrenaline-pumping and deeply rewarding moments.

“Overseas work has a whole different kind of impact. There’s something religious about it for me. You can’t overestimate the impact or significance of providing free medical care that changes the trajectory of a single person’s life. I know there’s a lot of push towards capacity building and building the system up, which I applaud. But while you’re there doing that, if you can also do something powerful for a single person that’s hugely important. The act of doing it is a loud proclamation that an individual human being has infinite value, dignity and worth.”

Photos and images supplied.

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