Ebola, Bike saddles, Recording consultations, Insect bites
Dr Mark Porter discusses the risk of Ebola cases in the UK, why bike saddles could cause erectile dysfunction, the pros and cons of recording consultations and insect bites.
Public Health authorities have written to doctors in the UK to ask them to look out for cases of Ebola following the recent outbreak in West Africa which has killed nearly 500 people. Dr Mark Porter talks to David Heymann, professor of infectious disease epidemiology at the London School of Hygiene and Tropical Medicine about the risks of Ebola cases coming to the UK. He is joined by Dr Margaret McCartney to discuss why some types of bike saddles can cause erectile dysfunction. He also talks to Glyn Elwyn about the pros and cons of recording consultations with your doctor Also, insect bites, why do some people get bitten more than others, what's the best repellent and what's the best treatment if you do get bitten?
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INSIDE HEALTH
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Programme 2.
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TX: Ìý08.07.14 Ìý2100-2130
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PRESENTER: ÌýMARK PORTER
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PRODUCER: ÌýPAMELA RUTHERFORD
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Porter
Coming up in today’s programme:
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Clip
… he’s miles ahead of everybody else at the minute, [name], this is a big sprint from a big guy, two wins out of three for the giant German.
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Brilliant day and when they came past unbelievable.
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I think it’s done England proud hasn’t it really.
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Thank you so much, it was unbelievable, incredible, it will be unforgettable what British people have done is just magnificent.
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De rien monsieur. ÌýIf the Tour de France has encouraged you to spend more time on two wheels, you might want to choose your saddle carefully in light of new research suggesting that cycling can have an unwelcome effect on your sex life. Margaret McCartney and I take to our bikes to learn more.
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Insect bites – if you have ever wondered why some people seem to get bitten more than anyone else. Or what the most effective repellents are? Or how to treat a bite if you are bitten? Then we have the answers coming up later.
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And recording consultations with your doctor – we will be discussing the pros and cons of keeping a permanent record of what they said.
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But first Ebola. Not something we normally give much consideration to here in Europe. But the biggest outbreak ever seen in West Africa has changed that, and prompted UK public health bodies to write to doctors urging them to be vigilant for signs of infection in travellers returning from Guinea, Liberia and Sierra Leone where Ebola has so far claimed around 500 lives.
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David Hayman is Professor of Infectious Disease Epidemiology at the London School of Hygiene and Tropical medicine. David, the fact that UK doctors have been warned about Ebola made the front page of Monday’s Metro and the public may have been alarmed by the fact that the authorities have felt it necessary to highlight the risk.
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Hayman
It’s always important to remind doctors of the importance of infection control. ÌýA patient with Ebola came into a hospital in Switzerland undiagnosed, it was a woman who had been working in Africa doing autopsies on dying chimpanzees. ÌýShe was hospitalised in isolation because they didn’t know what the infection was, there was no onward transmission, it wasn’t even known that she was infected until about six months later. ÌýSo these diseases can be prevented from spreading if hospital infection controls are what they should be and they are here in England.
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Porter
So there is a precedent for it travelling into Europe but the odds of the virus actually getting here are quite slim aren’t they?
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Hayman
The odds are slim but it’s always good to be on guard for any disease. ÌýLook at what happened two years ago when Mers Coronavirus, this virus that’s now in the Middle East, came into the United Kingdom, in England actually, into London, was hospitalised, unknown what the diagnosis was but there was no further transmission.
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Porter
One of the things about Ebola historically has been that epidemics seem to be very short lived because it kills people very quickly, there’s not much chance for it to spread to large geographical areas but that seems to have changed in this one?
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Hayman
Well the geographic area has changed but the basic principles are the same, it’s a very virulent virus and it can sustain its transmission long term because of that virulence. ÌýWhat’s happened in Africa at present is that the disease has gotten across border and there hasn’t been really enough commitment to educate populations in the communities about how this disease is spread and how they can prevent it.
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Porter
What happens in a typical case?
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Hayman
In a typical case there’s an initial infection and we don’t know how the initial infection in this outbreak occurred. ÌýBut after that it can be transmitted either by poor hospital practices where nurses, doctors and others are exposed to body secretions and become sick and then they unfortunately pass it on to others including their family members. ÌýSo it’s a disease that’s spread by close contact, it’s not spread through the air.
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Porter
What happens to the patient?
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Hayman
Well the patient becomes sick at the start, like any other disease in Africa, it’s a fever and it then continues on to muscle aches and it feels much like the flu from what I understand. ÌýAnd then there can be a period when the patient feels much better but then after that sickness again and some become quite sick with bleeding.
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Porter
What does the virus actually do to the body – how does it kill people?
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Hayman
Well the virus is a virus which is unknown to the human body, it’s a virus which isn’t – what we call – endemic, it’s a virus which comes and emerges periodically therefore there is no immunity in the human populations against this disease. ÌýSo when it comes it really has carte blanche to spread throughout the body and it does, it spreads throughout the body into most organs and it causes very severe damage to these organs.
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Porter
So what are these people actually dying of?
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Hayman
People die in shock, they die because the virus overwhelms their immune system, it overwhelms their bodily functions. ÌýSome die in haemorrhaging, others just die because their organs can no longer function properly.
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Porter
It’s called haemorrhagic fever, is another name for it, and that’s because it causes internal bleeding?
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Hayman
That’s correct, in some instances it causes internal bleeding and people haemorrhage from external orifices as well.
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Porter
What’s the outlook for someone who has Ebola?
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Hayman
Well there are several different strains of the Ebola virus and it depends on which strain infects them but some have a mortality rate of about 50%, which means that 50% of those infected will die but others go up as high as 80 or 90% depending on where it comes from.
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Porter
And how quickly might they die?
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Hayman
Well the disease takes a period of five to seven days before the maximum impact and death.
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Porter
Can we treat it at all?
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Hayman
It’s treated by maintaining the patient’s bodily functions by providing fluids when necessary, by helping the patient breathe if necessary – usual supportive measures that are done for all seriously ill patients.
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Porter
But we don’t have any specific agent – an antiviral, for instance, that’s effective against the virus?
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Hayman
No unfortunately there’s no antiviral or any drug that can be used to treat it. ÌýBut there is research going on, especially in North America, looking at vaccines and also at antibodies which could be used to treat people who are sick to help them overcome the infection.
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Porter
Professor David Hayman and there is a link to the letter from Public Health England on the Inside Health page of the Radio4 website. But the key advice is for doctors to be vigilant for travellers who develop flu like symptoms within 21 days of returning from affected areas in West Africa.
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The start of this year’s Tour de France has been widely cited as the best ever. But if you have been caught up in the euphoria and plan to spend more time on your bike you might want to give some consideration to what you are sitting on. I joined Dr Margaret McCartney on the busy streets of London to find out why.
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Off you go, it’s clear behind. ÌýApologies for lack of signals.
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McCartney
It’s a lovely day.
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Porter
I mean Margaret people might think of the saddle as being a bit uncomfortable but what other problems can it cause?
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McCartney
Over the last decade there has been quite a lot of research done about the types of saddles that people use for cycling, which is after all a very healthy activity but the problems that the bad – bad sorts of saddles can cause. ÌýWhat we’re really talking about is the nose saddles, the kind of cyclists that use these – tend to be speed cyclists or cyclists who are looking for a kind of an aerodynamic ride – the very long and thin saddles.
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Porter
This is the nose the bit that basically goes between your legs, what we call the perineum sits on?
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McCartney
That’s right, that’s right, so they tend to be long and thin, these kinds of saddles, but what happens is that your bodyweight tends to rest right in the middle, which is not really the best thing for your body. ÌýNormally when you’re sitting you sit on your – what we call your sit bone, your ischial tuberosities of your pelvis, that’s normally where your weight would go when you’re sitting down but when you’re sitting on one of these nosed cycle seats your weight tends to go right in the middle, right in the middle where your genitals are, where your penis, vagina, clitoris all are, all of which do need nerve supply and blood supply in order to function properly.
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Porter
So what sort of problems might people get from this nose – what symptoms?
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McCartney
Well there was a really interesting study done in America a few years ago and they asked policemen who were policemen on bicycles, so their patrols were involving being on a bike for most of their working week, and they asked them how many of them had numbness around about their penis or genitals and only a third of them said that they never got any problems with numbness.
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Porter
So two-thirds – and these are guys presumably who are spending – men and women – who are spending a lot of time in the saddle?
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McCartney
Yeah absolutely, the majority of their working week was spent cycling around. ÌýAnd cycling is indeed healthy, if you do a little bit of cycling, less than three hours a week, there’s a decreased chance of men having erectile dysfunction but if it’s more than three hours a week there’s actually a small increased risk of having erectile problems.
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Porter
So the link between erectile dysfunction – problems getting a proper erection – and sitting in the saddle, it’s pressing on what that’s causing the trouble?
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McCartney
Well it’s the nerve bundle and the arteries that go on to supply all the vascular tissue that you need in order for the penis to work properly and to make erections. ÌýSo if you’re causing a lot of pressure to be on those nerves and blood vessels over time you end up causing an impairment. ÌýSo in this study they asked the policemen not to use nose saddles anymore but to use no-nose saddles, a different type of cycle seat that doesn’t put any pressure right in the middle in between your legs. ÌýAnd what they found was that after using them only a third of men had some genital symptoms, the huge amount of men that were getting genital symptoms didn’t get them anymore after changing their type of cycle seat.
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Porter
What about the effect on their sex lives, I mean were they having problems as a group?
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McCartney
Well the questions that they were asking were more around the blood supply to the penis, so they did a special overnight study where they measured the blood supply to the penis and found that when they changed the saddle type more men had more blood flow with what they call more erections, more tumescence episodes during the night. ÌýSo a change in saddles led to more spontaneous erections overnight for these men.
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Porter
So that was suggesting that saddles were having an effect on them, even though they might not have noticed it in their sex life?
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McCartney
That’s right, that’s right.
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Porter
Let’s go left here and then we’ll get off the bikes and have a look at the saddles.
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Now Margaret I’m on a Boris bike, which has got a pretty wide comfy saddle but I presume these policemen had pretty comfortable saddles, they weren’t on racing saddles like the guy who’s just gone past us.
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McCartney
No, no they weren’t but the type of saddles that they changed to were actually quite different. ÌýSo if you can imagine a normal cycle saddle essentially they’ve got what looks like two of them but with a space in between, so each of your buttocks has its own special little seat to sit on and that puts all the weight down on your pelvic bones rather than being concentrated right in the middle in between your legs.
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Porter
I mean one of the problems is that when people wear – you can buy shorts, can’t you, which are padded but the padding is mainly on the back isn’t it, on the buttock side, rather than sitting on this crucial area, what we call the nose?
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McCartney
Yeah, absolutely, so you have to question really whether padding actually makes any difference at all or whether it actually makes you think you’re doing something useful when actually you’re not because what you really need to look at is where your weight’s being transferred to and if it’s still being transferred in the middle, in between your legs, it’s really not doing the job that a good saddle should do for you.
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Porter
Do we know if this damage, this pressure, is irreversible and might you do longstanding damage or if you stop riding the bike things get better?
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McCartney
Yeah, so there’s a definitely a lack of good quality studies looking at this but there’s lots of smaller studies and lots of urologists making reports that when they’ve told people, particularly young men, with no other risk factors for erectile dysfunction to change their cycle seat they’ve had pretty good results. ÌýAnd what they’re saying is that if you’ve got a young man, no other risk factors for erectile dysfunction except for the fact that he rides a bike an awful lot it might be a good thing to think about a change in saddle type because that might actually help you quite a bit.
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Porter
Did the policemen in the study complain about using the new saddle, was there a disadvantage in not having a nose?
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McCartney
Yeah, so there’s two issues have been raised by the manufacturers of these wider seats, two issues that people say they’ve been concerned about are that they don’t feel as stable on these wider saddles and the other question is whether people feel it’s a bit uncool whether in having a wider saddle they’re kind of saying I might have a problem. ÌýBut in the study of American policemen they found that only three out of the 90 men wanted to go back to their nosed saddles, the rest of them wanting to stick with the wider less cool looking but perhaps better for you saddles that the manufacturers had to offer. ÌýI have to say I was interested in this area after cycling on my husband’s bike for the afternoon and I had a very numb bottom afterwards and I was really thinking that’s quite an impressive cause and effect and it took a couple of days for my bottom to go back to normal again.
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Porter
Because we’ve talked about the effect on men but women have some pretty crucial anatomy down there as well.
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McCartney
Yeah absolutely and one of the big things to remember is that your genitals aren’t just outside, an awful lot of the vascular tissue that makes your penis and your clitoris work properly is actually internal to your pelvis, so it’s not just what you can see outside, it’s actually what’s inside as well, there’s a huge amount of tissue in there that you need to work properly in order for your genitals to work properly.
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Porter
So you’re effectively sitting on a hidden but large proportion of your clitoris and your penis?
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McCartney
Absolutely and if you’re putting all your weight in that small area you’re obviously going to affect the blood vessels and the nerves, so using a wider based saddle actually transfers that weight, instead of being in the middle of your legs, right over to the side right on to your pelvis which is really what our human bodies are designed to take the weight on.
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Porter
I’m going to stand up on the way back.
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Actually Boris bike saddles are very comfortable even with a nose. There is a link to the research that Margaret McCartney mentioned on our website.
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Now, how easy do you find it to remember everything your doctor says during a consultation? Are you clear about your diagnosis? Or how they wanted you to take your medicines? If you struggle – and most people do – have you considered recording what happens when you visit your doctor? It has become routine practice for this patient.
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Patient
I record the consultations I think that are going to be most useful, so if I’m seeing a specialist who’s done some in depth investigations then I’ll take in a recorder and sometimes I’ll record a consultation just when I know it’s going to have a lot of points of detail and I just don’t have time to write it all down and I don’t have time to have somebody with me or maybe it’s so private I don’t want somebody with me. ÌýI feel I have to do it covertly because I don’t want to get the same reaction I had with my GP who effectively wanted to strike me off the list. ÌýThe recordings have been more useful than you can imagine. ÌýI think that patients only hear half of what is said in the consultation and subsequently they remember even less. ÌýSo when I’ve had quite long and detailed consultations I can play the recording back later, sometimes I actually write the recording out by hand. ÌýI find them invaluable.
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Porter
But how do doctors react? Professor Glyn Elwyn from the Dartmouth Centre for Health Care Delivery Science in the US is at the forefront of research in this area.
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Elwyn
We’ve been studying actually the reactions of doctors when they’ve found out that somebody’s been recording them in secret and they’re usually a bit upset or affronted or annoyed even and there’s reports of doctors asking patients to leave the practice when they’ve found this out. ÌýAnd when people ask whether or not they can record I think there’s a bit of defensiveness that comes in as to why would you do that, what’s the reason behind it. ÌýSo there’s a great sense of defensiveness I think is the initial reaction.
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Porter
The field of oncology, cancer medicine, has led the way in this, I mean I’ve had patients who – for a number of years now – have had some of their consultations recorded by their oncologists so that when they get home, as you said, they can go through it again because they often lose a lot of the detail during that – what can be quite a traumatic period.
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Elwyn
Exactly, when you’re breaking bad news or you’re trying to explain detailed chemotherapy your patients are emotional, they hardly remember much of what is said so having a recording is incredibly valuable for them and their family and oncology has led the way in providing patients with those recordings and offering them.
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Porter
Why has it taken root in cancer treatment and not elsewhere?
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Elwyn
I think there’s been an interest in some of the cancer specialities in doctor/patient communication and really doing that well and they therefore realise that patients have a limited amount of recall and patients, clearly from the research we’ve done, value it tremendously.
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Porter
Margaret, have you ever had a patient ask you if they can record a consultation and if so why?
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McCartney
Yeah once or twice and it’s been pretty uncommon really and I can absolutely concur, there’s lots of evidence out there, that says that people find it quite difficult to retain all the information that they’re given really quite intensively over just 10 or 15 minutes in the consulting room. ÌýSo I think absolutely I can see why it is that many patients might find it to be useful to have a permanent record of what the consultation was.
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Porter
My concern, I suppose, as a GP might be what would happen to that recording, I don’t mind the patient having it but these days it could be posted almost anywhere.
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McCartney
Absolutely, to me it’s about intention – who are the doctor and patient on the side of? ÌýIf they’re on each other’s side perfect – doctors and patients working together, the information from the consultation being used to benefit the patient and possibly their family as well – perfect. ÌýI think when many doctors might get concerned is if the doctor and patient are actually on different teams and if perhaps there is some kind of other intention with the recording to sue doctors or to make a legal case against them somehow. ÌýI think that kind of thing will inevitably make many doctors, including myself, quite frightened about it when of course general practice is one of those funny specialities that’s one consultation over a whole lifetime you don’t often fix everything in one 10 minute appointment, it can take place over many appointments. ÌýSo it may not be represented very well in one excerpt of one consultation.
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Porter
Glyn, I suppose there’s an argument that we should be consulting with our patients as if we’re being recorded all the time?
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Elwyn
In fact that seems to be the advice coming from the defence societies, almost assume that you’re on tape, as it were, because you really these days don’t probably know when somebody’s left a recorder on. ÌýThat does raise issues I think of worry about that leading to defensive medicine, doing too many tests or many all the referrals that you can in order to defend yourself against a complaint. ÌýSo I think making this overt and explicit is probably the best way to go and I think it’ll probably in the end people will begin to realise that they need to perform, if you like, or have encounters such that they’re really consulting the evidence base involving patients, sharing doubts and uncertainties as well as certainties so that you’re as transparent as you possibly can.
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Porter
Note taking in medicine has been transformed during the 25 years that I’ve been in practice, I can remember when I first arrived in general practice that you just have one word in the notes, something like tonsillitis would be written, we take much more detailed notes. ÌýDo you see, looking forward, that maybe in a decade or so that we’ll be recording everything?
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Elwyn
I suspect that with the advent of digital recording now and the price dropping that we may well have a permanent record in the institution as well as offered to patients. ÌýWe see the advent of open notes in the US where patients can comment and even edit their own notes and I see almost an archive of digital recordings being available to patients’ families and the practitioners. ÌýBut the safeguards around that have to be very carefully instituted I think.
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Porter
Is there any evidence that attitudes vary depending on how old the doctor is, I think this might be a generational thing in that younger doctors are often brought up – part of their training – of being filmed, videoed, recorded?
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Elwyn
We don’t know and to be honest with you we really don’t know how common this habit is at the moment and in fact that’s something I’d love to hear from doctors and from patients as to their views and approaches to this issue.
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Porter
So Glyn how can our listeners help?
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Elwyn
What we’d like to know is have you done it, why have you done it, what was the reaction – perhaps if you asked for permission or why didn’t you ask for permission and what did you benefit from it. ÌýWe’d love to hear from you and we have a short survey – we ask four questions, they’re very short – and we’d love to hear from everybody – from doctors and from patients.
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Porter
Professor Glyn Elwyn and Dr Margaret McCartney, and there’s a link to that survey that Glyn would like your help with on our website. ÌýWhere you will also find details of how to get in touch if there is a health issue that you would like us to look into.
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A female listener e-mailed to ask about insect bites – why do some people react more than others? She has particular problems. ÌýAnd what is the best way to treat them if you are unlucky enough to be bitten?
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Dr James Cave is Editor of the Drug and Therapeutics Bulletin.
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Cave
It’s never been a particularly important area I suppose for a lot of researchers so we have very, very poor evidence for treatments for insect bites.
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Porter
Let’s look at somebody who’s had trouble from – we probably don’t know what it is – but a mosquito and they’ve come in and they’ve got a big inflamed bite – how would you approach that from a science point of view, if they need your help, if it’s severe enough to warrant seeing a doctor?
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Cave
Yes I mean I think if they’ve had a really bad reaction I think the first thing is the simple first aid stuff, so elevate if it’s a leg and classically it does seem to be legs, doesn’t it, that always get really swollen. ÌýSo if it’s swollen elevate it, get some cold on to it because that reduces the ongoing inflammation within the tissues. ÌýAnd the two things we tend to use are antihistamines and/or topical steroids, mild sort of hydrocortisones.
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Porter
The listener has asked about using cream, she reacts very badly and asks about antihistamine creams and hydrocortisone. ÌýWhat would be your choice for a topical treatment?
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Cave
I think if I was going to use something – and the evidence for both of those is not good – I would go for the hydrocortisone cream. ÌýAnd the reason for that is that we have got some evidence that the antihistamine creams are quite reactive and people sometimes have an allergic reaction to them.
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Porter
Paradoxically.
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Cave
Paradoxically – so they get worse because of the cream.Ìý
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Porter
So go for an antihistamine tablet and apply a topical steroid cream like hydrocortisone.
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Cave
Precisely.
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Porter
And they’re slow to act as well aren’t they, these don’t provide relief within 30 minutes so the earlier you apply them – I mean it’s hours, days sometimes?
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Cave
Precisely and of course if you’ve already created a very big reaction and you’ve got cell breakdown and inflammation in the tissues then it’s going to take a lot to reverse all that, so probably the earlier you apply it the better. ÌýI often say to patients if it’s getting itchy the last thing you want to do is scratch it.
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Porter
Yes because the mechanical act of itching will create or worsen the inflammation.
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Cave
Oh definitely and we all know, as GPs, that huge swelling with the top of the bite’s being sort of knocked off and it’s got that look and you think oh goodness you’ve just been having a good old scratch and you’ve just made it twice as worse.
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Porter
What about the role of antibiotics because it can be quite difficult when you’re looking at something to see whether they’ve got an infection there or whether it’s just a lot of inflammation, an allergic reaction?
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Cave
I think that’s a really difficult area. ÌýI mean clearly if someone comes in and they’ve got lymphangitis, you know the red streak climbing up their leg or their arm which in the good old days you were told if it got to your heart you were dead and of course I’m not sure that’s strictly true but you know if they’ve got lymphangitis and they’ve got feeling of flu like symptoms well that’s easy – they need antibiotics. ÌýBut the patient who’s just got a really bad reaction I suspect we over treat those with antibiotics and I think sometimes what we should perhaps be saying to those patients is I don’t think you need them, what about a deferred ‘script, I’ll put one aside for you, give it a day of really resting it – elevating it – do all the right things, if it’s worse tomorrow come in and pick up some antibiotics.
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Porter
Dr James Cave.Ìý
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But what about the listener’s question as to why some people seem more susceptible to bites? Dr Ian Burgess is Director of Insect Research and Development Ltd in Cambridge. So, are some of us just more attractive to insects than others?
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Burgess
Yes with reservations. ÌýThere has been some work on this looking at the bacteria living on the skin and if you have smelly feet you’re more likely to be attractive, not absolutely, but those bacteria that create the smelly feet also produce volatile compounds from the skin and those become detected by the mosquitos. ÌýAnd the other thing is that it appears that certain blood groups and tissue types may be more attractive but the work that’s been done on that is very limited so I wouldn’t like to go any further on it.
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Porter
My wife always complains that women seem to get bitten more than men – is there anything behind that?
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Burgess
I don’t think so, it may be that you react differently and of course if you have two people together one may be more attractive and of course women tend to use perfumey type materials more frequently than men, even when they’re just going for a walk in the hills and so that may be a factor in attracting them.
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Porter
Talking about reaction why is it that some people seem to react much more than others?
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Burgess
Well that’s in relation to how much you’ve been bitten before. ÌýWhen we’re first born we don’t react at all and we only respond after we’ve been bitten a fair number of times and it depends on what you’ve been bitten by and where it is. ÌýBut after a period of time you become immunised basically and so the body responds in pretty much the same way as it would respond to any other foreign protein that’s injected into the skin and that’s where we get the large red itchy lump that people in Britain and most of Western Europe are familiar with. ÌýHowever, if you get bitten still more then over a period of time you start to change, the big red itchy lump never appears until about eight to 72 hours after the bite anyway but with further biting you start to show an immediate reaction which is a little wheal that appears within a few minutes of the bite and then it’s followed by the itchy lump and if you’re bitten still more then the itchy lump slowly disappears and you just get the wheal. ÌýAnd finally if you really get bitten a lot then you don’t respond at all, other than the trauma of the initial biting which is an intense itchy burning feeling and then it passes within a few minutes.
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Porter
What about the use of repellents, what’s the most effective repellent for stopping yourself being bitten?
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Burgess
Well we have a fairly limited choice of repellents these days because since the introduction of the Bioscience Directive the number of materials that’s available has diminished. ÌýSo we really only have a choice of about four compounds, still deet is regarded as the gold standard and then you have three others, there are two other synthetics and one that’s derived from lemon eucalyptus.
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Porter
And what about – I mean citronella historically has been a very popular alternative to repellents like deet, does it work?
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Burgess
Citronella has a very limited effect anyway and in fact is no longer permitted in the European Union under the Bioscience Product Directive because nobody supported it. ÌýBut it probably wasn’t worth having anyway and the chemical called P Menthane Diol, which is derived from lemon eucalyptus, is far more effective and is a supported chemical.
Ìý
Porter
Are there particular danger periods when you’re most likely to be bitten, I think most people will be familiar with the fact that it’s in the evening and you’re having a quiet – you’re on holiday having a drink outside and the next thing you know you’re under attack?
Ìý
Burgess
Well it depends where you are and what you’re likely to be attacked by. ÌýIf you are maybe say in Greece and you’re going to the taverna in the evening then the probability is you’re going to be attacked by something like a South European house mosquito and its relatives are found throughout the tropics and they will come and bite at around dusk. ÌýIn fact I’ve seen them literally rising from their daytime refugees as the sun touched the horizon in Bangladesh and then within about two or three minutes you look down at your feet and the ground shimmers in the twilight from the wings of these things. ÌýSo literally crepuscular, as the sun sets, they start and then they will bite at various intensities throughout the early part of the night. ÌýSimilarly with malaria carrying Anopheles mosquitoes, the vast majority of them start to bite at sunset, they will peak towards midnight, tail off again and then they’ll be another little peak towards dawn.
Ìý
Porter
Dr Ian Burgess.
Ìý
Just time to tell you about next week’s special programme on breast screening. Why have the authorities in Switzerland decided against introducing a national breast cancer screening programme? While a similar review here in the UK has recommended we should continue with ours despite recent concerns that the benefits may not be as clear cut as many women believe? Join me next week to find out.
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ÌýENDS
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- Tue 8 Jul 2014 21:00Â鶹ԼÅÄ Radio 4
- Wed 9 Jul 2014 15:30Â鶹ԼÅÄ Radio 4 FM
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