A commonly prescribed antibiotic might have saved Trevor Lunn’s life, but its legacy has been profound, reports Julie Milland.
Trevor Lunn doesn’t blame his doctors or the hospital for the disability he will carry for the rest of his life.
The Geelong man’s ordeal began when he noticed a little blood in his urine in March last year, prompting his doctors to carry out a routine investigation.
The good news was he didn’t have any growths or problems with his bladder. The bad news was that two days later he was rushed back to hospital with a high fever and one enlarged testicle that grew to be the size of a tennis ball.
Mr Lunn had a potentially life-threatening infection and needed two types of antibiotics, as well as morphine for the incredible pain. This is where the story of his disability really begins.
“When I was in hospital I was aware I [felt] what I would have called ‘loopy’,” he recalls. “Everything seemed to be swirling around me and I thought that it was the morphine. Nothing seemed stable. To get out of bed; it was a challenge.”
The infection subsided and he went home after four or five days but “the loopiness didn’t go away”.
“I put up with it for a little while and I had a couple of panic attacks just because this is such a weird experience. It’s hard to define what it is.”
Mr Lunn collapsed and was rushed to hospital again where doctors checked his heart. After a second collapse, he finally wound up at a specialist who said the balance organs in his ears were damaged.
One year on, the 69-year-old feels both lucky and unlucky. He feels unlucky because he contracted an infection that needed immediate and life-saving treatment with an antibiotic called gentamicin. He feels lucky because gentamicin only destroyed 70 per cent of the balance function in his left ear and 40 per cent in the right. He says it could have been much worse.
“I wish it hadn’t happened, of course. But it did. It’s just one of those unlucky breaks.
“The hospital and the doctor that did the original work on me were acting in what they considered to be my best interests. I don’t think they cut any corners.
“I think they did everything that you would expect of a good hospital and a good surgeon. I was just an unlucky guy and so that’s just the way it goes.”
Mr Lunn’s situation illustrates a clash between two medical conundrums in an era when antibiotic resistance threatens our modern health system.
The first conundrum is that gentamicin is an important antibiotic that saves lives and is less likely to cause antibiotic resistance in bacteria, but it is also toxic to small cells in the inner ear that contribute to a person’s ability to balance. Gentamicin caused Mr Lunn’s feeling of “loopiness”.
The second conundrum is that doctors are trying to cut the use of antibiotics to reduce antimicrobial resistance, and so want to limit the routine practice of giving antibiotics before surgery as a means of avoiding post-surgery infection. While Mr Lunn’s surgeon did not routinely use antibiotic treatment before surgery he has since changed his protocol because of Mr Lunn’s experience.
While gentamicin is effective, some people are more likely than others to have a balance problem after taking it. Although the drug can save lives, a 2012 study found that any dose of gentamicin could be toxic, with older people at greatest risk.
Professor Allen Cheng, the deputy head of infection prevention and healthcare epidemiology at Alfred Health, says there is now a lot of awareness that even very short courses of gentamicin can be toxic, so doctors try not to use it unless they have no choice. He points out that all medications create a risk-and-benefit equation.
“There are still quite low rates of resistance [for gentamicin] with a lot of bacteria, and it’s still quite an effective antibiotic and it kills bacteria really quickly. So in people who are really sick, like going into intensive care with septic shock, it’s still one of the go-to antibiotics we use for that particular patient group.”
Dr David Szmulewicz, who treats people with balance disorders at the Royal Victorian Eye and Ear Hospital, and who assessed Mr Lunn, says his unit can test exactly how much damage a person has in their balance organ, which is called the vestibular system.
He says there are no published standard protocols for bedside testing of vestibular function so he and audiologist Brooke Paisley are developing a protocol to detect balance problems as early as possible. There is still a lot to learn about the way the vestibular system works.
“The inner ear balance mechanism lives very deep within the base of the skull bone and it’s not usually accessible during life, so we can’t easily get a sample of the cells in there or the fluid in order to help us understand what’s happening with a certain disease,” he says.
In order to better understand balance disorders, Dr Szmulewicz helped establish the Australian Temporal Bone Bank in 2014. “Basically, our aim is to be able to further our understanding of balance and hearing disorders by encouraging people who have balance or hearing disorders to donate their temporal bones after life.”
He says an individual’s balance is made up of three parts, which work together to maintain balance. The first is the hair cells in the vestibular system in the inner ear that stand like “goal posts” and act like a spirit level, moving as the person moves and directing their eyes to move in the opposite direction. The other parts of the human balance system are vision and the receptors in the joints and limbs that detect movement and send messages back to the brain (proprioception).
If the hair cells are totally destroyed by gentamicin, people are left with only the other two systems. But if vision or proprioception are also compromised — for example, when a person is walking in the dark or if the feeling in their lower limbs is reduced, as occurs in diabetes — then walking becomes very difficult, even for people with some remaining vestibular function.
Dr Szmulewicz says the damage to hair cells caused by gentamicin is permanent but the brain can adapt in some people to compensate for the loss. “[Some] patients can recover their balance and this is thought to be our ability to adapt or compensate. Another term [for this] might be neuroplasticity. Exactly what goes on with this compensation or adaptation is unknown but there are a few mechanisms that are thought to be active,” he says.
“One of these is that it’s thought that the brain is able to redistribute or bias other parts of the balance mechanism to get further information. So, for instance, if the inner ear balance mechanism is damaged then the person might rely more on vision . . . or more on where their leg is in space, if you like, to pick up the slack.”
He says although some people can adapt to the loss of function in the vestibular organ, there is no medication to treat this problem.
“Interestingly, the only evidence-based or research-backed method of improving this process is vestibular rehabilitation.”
Arimbi Winoto, who is a vestibular physiotherapist specialising in rehabilitation for people with balance problems at Royal Victorian Eye and Ear Hospital, says the damage from gentamicin is confusing for people because they don’t feel dizzy or have vertigo as a symptom.
“What they feel is that they have no sense of balance, particularly in the dark or particularly if it’s a really busy environment. What some people will also report is that the world doesn’t stay still when they move around . . . whenever they walk or move their heads in any way. So, when nodding when they’re talking, the world won’t remain still on their retina. The world will actually be bouncing up and down with their head movements.”
Vision can also blur with head movements so that people cannot recognise faces or read street signs as they walk or move.
“The other thing that they’ll really clearly say is that they’re incredibly unsteady on their feet,” Ms Winoto continues. “Especially when they first get up out of the hospital bed and that’s often when it’s first noticed because usually these people are given gentamicin not for fun, they’re given it because they’re seriously unwell.”
Ms Winoto said that, sadly, some people are never diagnosed because of a lack of medical records and others are not diagnosed for many years. One of her clients was using a walking frame for 15 years after a hip replacement. She was able to obtain his medical records and found he had been given gentamicin. She says even after many years, knowing the correct diagnosis can help people.
“In terms of the people who are not affected as much, then regular vestibular physiotherapy or even just balance physiotherapy will help enormously. And even for people like that man [with the hip replacement], we could never get him off the frame but I think the way we were able to help . . . was with a lot of education.”
Ms Winoto says education can help to mitigate the risks but even for people with some function left in the vestibular system, rehabilitation takes months or years. The rehabilitation aims to maximise and retrain remaining balance function and some people are able to walk without a frame.
Mr Lunn says he awoke with debilitating nausea for six months. But after a year of rehabilitation he feels much better and has signed up to donate his temporal bones after he dies.
“They can’t get down there into the [balance] organs and find out what the damage looks like. They can only do it after death. So they’ll take my two little temporal bones and check them out and see what it was all about.” He laughs, before adding: “And I’ll never know.”