"I think these jobs are all-consuming, really," says Dr David Throssell, Sheffield Teaching Hospitals' medical director who retires this week after 32 years in the NHS.
As the man tasked with overseeing clinical standards in an organisation that employs 15,000 staff admits, there are 'always things happening' that need to be resolved.
"But that's the deal, I'm not complaining, I absolutely knew that when I took it on. You need somebody who carries the can. But on the other hand, it's not necessarily something you can do forever."
While he has worked at the top tier of management in Sheffield's health service, Dr Throssell didn't hone his skills in an office environment. He is an expert in kidney disease, having practised as a consultant in the field - and within about a minute of stepping into the renal unit for photographs at the Northern General Hospital, he's back in doctoral mode: sleeves rolled up, wristwatch off and straight to a dialysis patient's bedside.
"With most specialties, a lot of the interactions with patients are relatively brief," he says. "All these patients come here three times a week, for years - hopefully they'll be transplanted, but you have that long-term relationship which is really valuable. You also see patients who come in acutely unwell, because kidney disease can strike very quickly. There's still the satisfaction of dealing with emergency situations, which I enjoy. There are few specialties that give you that combination."
Dr Throssell joined the Northern General in 1996, 10 years after he qualified and following spells in other places - it represented a return to his home city, as he grew up in Stocksbridge where his father ran a chemist's shop. His parents, now aged in their late 80s, still live in Thurgoland.
"It was funny. Our name is quite unusual, so when I came back to Sheffield I would meet patients who'd say 'Are you Brian's son?' As a pharmacist somewhere like that, if you're there for 30 years, you see most people in the town. Stocksbridge wasn't somewhere people moved in and out of so much, it's more so now, but then everyone who lived there worked in the steelworks. I had to behave myself because they'd report back to my dad if I didn't."
He trained in Manchester, choosing medicine because he was interested in biological sciences, 'but not in an abstract sense'. "It's that combination of the science, but also the human element - medicine as an art of talking to people, of engaging with them."
One of the biggest changes he has witnessed, he thinks, is a move away from doctors being 'all-seeing gods' - lofty, paternalistic figures who simply told patients what to do. The character of Sir Lancelot Spratt, a domineering surgeon played by James Robertson Justice in the 'Doctor' films of the 1950s and 60s, was all too realistic, he says.
"I know that's a bit of a caricature, but genuinely some doctors were like that 30, 40 years ago. It's very rare to see that now. That's been reflected in the way doctors are trained as well, there's much more focus on communication skills and the art of medicine, which was never taught. We all know patients have confidence in you if you talk to them and can relate to them. Actually, however good you are at the technicalities, if people don't trust you because they can't engage with you on a personal level, they won't trust you at a professional level."
Patients are now more involved in their treatment, he says, one example being a 'shared care' programme in which people play a bigger part in administering their own dialysis.
"There's very good evidence that if you do that, they're more likely to do the right things for themselves because they understand the reason for it."
He moved to Cardiff after a period in Leicester, where he met an 'inspirational consultant', Professor John Walls, who sparked his interest in nephrology. At university he had already taken a year out to gain an extra degree in physiology, which dealt with many of the principles that underpin kidney function. "I suppose I was already ripe for that area," he says, smiling.
He became a consultant in Sheffield in 2000, stepping up to the role of clinical director two-and-a-half years later. "There comes a point in your career where you think 'How can I develop this service?' You see things that you think could be done better."
The city's provision for kidney patients has been hugely expanded since the mid-1990s, from new facilities at the Northern General to satellite dialysis units in Chesterfield, Barnsley, Rotherham and at Heeley, mirroring a wider trend towards widening access to treatment. "Now, anyone who needs dialysis can have it in this country, which is fantastic."
Dr Throssell has also focused on the problems faced by women with kidney illnesses who wish to conceive. "That's hugely rewarding. One of the problems for women who have kidney disease is it will affect fertility, so it's very uncommon for a woman who's on dialysis to get pregnant. The best chance is if they have a transplant, so I've run a clinic that deals with that, together with an obstetrician. A lot of these women have thought they could never have a child."
One such former patient, he says, wrote to him two weeks ago after hearing of his retirement. "She sent me a photograph of her with her son, who's now about five. It's a huge thing for these women."
He has a good memory for ex-patients generally. Even from his days in Leicester he can recall individuals who were brought in late at night to find they needed dialysis immediately.
"I can still remember their names. What sticks in your mind is how stoical people are - they come in, they thought they were alright, and within two hours you've got them stuck to one of these machines. You can't imagine a thing much more terrifying than that, but the way people cope with it is just astonishing, really."
He was appointed medical director in 2012, having already served as a deputy to his predecessor, Prof Mike Richmond.
"It's a huge organisation. Across the whole trust you're dealing with areas you're much less familiar with - things like dentistry, for example, which clearly I'd never been involved with. But actually the principles of management, and dealing with people and patients, are all the same really. You have the clinical directors to deal with their particular areas and it's about overseeing that."
However, to be a boss with a seat at the directors' table wasn't something he'd ever particularly aspired to, he says.
"If I thought this was a bit of tokenism, to have a doctor on the board because you have to, I wouldn't have been interested. But it genuinely isn't that, people are really listening to the clinicians. That does frame the direction of the trust, which is exactly what you want."
He talks of strategy, and driving improvement; many services have been shuffled between the Hallamshire and Northern General sites in recent years.
"That's been about clinical synergies. At the Hallamshire we've got all the head and neck specialties, which need to be close together, whereas at the Northern General we've got renal and cardiac where there's often a lot of cross-talk."
The big merger that formed Sheffield Teaching Hospitals NHS Foundation Trust in 2001 has, he believes, shown itself to be 'very successful'.
"In some cities I think it was enforced and people's heart wasn't in it, whereas in Sheffield I think there genuinely was a recognition that it made complete sense to work together."
He accepts the NHS faces major challenges around recruitment and the ageing population, but has confidence for the future.
"Despite what we might sometimes hear I think the NHS is a hugely strong organisation. It's an over-used phrase, but it is a national treasure and people genuinely believe in it. I think that will keep it going. Any politician of whatever colour who tried to change the fundamental principle of 'free at the point of care' would struggle, really."
In 2017, when the WannaCry cyber attack spread to NHS computers, Sheffield's senior managers showed their dedication despite the trust not being affected by the ransomware virus.
"That happened on a Friday evening, the worst possible time. We had an emergency meeting and set up a 24/7 rota - we sent out a blank template and by seven o'clock on Saturday morning it was fully populated with people volunteering to come and help. We've seen that in other crises as well. I'd be surprised if that happened in some other industry on a Friday night. Nobody's expecting to get loads of extra pay for that, they just want to sort the problem because they're passionate about the services. It's that that I'll miss more than anything, that camaraderie."
Dr Throssell's retirement follows the departures of Sir Andrew Cash, the trust's chief executive, and Prof Dame Hilary Chapman, its chief nurse.
"It's just coincidence, really, in terms of the timing. But there is a very stable management team. It's not lots of new people coming in. That's one of the advantages of an organisation of this size, that there is always a succession plan."
One of his deputies, Dr David Hughes, has been picked as the next medical director, creating a 'seamless' transition. "Which is great, and makes me much happier."
Dr Throssell lives in High Green, has two children who are both at university and is married to Tania Barnes, a nurse who runs a national course that shows how patients can be trained to do dialysis. "She's certainly not retiring, so it'll be nice to give her some support, because she's obviously given me lots."
Hill walking, mastering languages, travel and photography are all on his activity list now he has more free time - and he wants to re-learn the piano.
Aged 57, he is aware his retirement is 'a bit early'. "Which is why I'm planning to do some other things. I'm not planning to put my feet up and do nothing."
He hasn't made any decisions yet, but has various options, 'both clinical and management'. "I think the thing to do is stop, have a break and think about what you want to do."
One of Dr David Throssell's top responsibilities has been to maintain patients' safety at Sheffield's hospitals - but is it unrealistic to hope every error can be prevented?
"Healthcare is a high risk business, there's no question of that. The things we do to patients, if they're not done right, are risky. Can you ever guarantee there won't be a problem? No, you can't. In the same way you can't guarantee nobody will ever have a road accident or a plane won't crash. But - and I think there's much more focus on this now than there ever used to be - patient safety always has primacy in any development we do, and in the processes and procedures we set up."
There are now standardised methods for treating patients, he says - "When I was a junior doctor, the way consultants operated would be quite starkly different" - and bodies like NICE trawl data to come up with a consensus on the best ways of working, so medics 'aren't doing maverick things'.
Even across Sheffield Teaching Hospitals, staff will encounter the same equipment - one type of syringe driver is used, for instance, to avoid unfamiliarity.
"We're not complacent. Even the treatments we do here," he says of the dialysis unit, "These are people with blood going through lines at 300ml a minute - if those lines come out, they could lose all their blood in no time at all. You have to have in place things that make sure that doesn't happen. Safety is paramount. And the more complex treatments get, the more important that becomes."