Which laboratory test would the nurse monitor to best determine a patients kidney function?

So people wonder why we ask to test the urine when you have got chronic kidney disease, and that’s because testing the urine helps us to look at kidney function in a different way. So I’ve explained at the start that often we pick up chronic kidney disease by doing a blood test where we look for the waste product called creatinine, and you look at the level changing and rising as the kidneys work less efficiently. But we can also look at the efficiency of the kidneys working as a filter. Now the kidneys are remarkably clever. They filter our blood. They keep inside the blood stream all the things we want to keep in, and they allow out the waste products and metabolised drugs, and other things that we actually want to get rid of. And the idea is there is a membrane between the two layers which keeps the things we want to keep in and allows the other things to get out.

Now there are processes that can damage that membrane so it allows things to get out into the urine that wouldn’t normally be there. And the thing we look for particularly is a small protein called albumin, and that detects very small amounts of damage to that membrane and we can pick up very readily on a urine test the amount of albumin in the urine. Over time many of our patients with CKD will get albumin in the urine, but there is a particular group of people where albumin occurs early. So if you have got diabetes, the first sign of damage to the kidneys isn’t on the blood test - so the creatinine level may be normal - but we see leakage through the kidneys into the urine of albumin.

So for people with diabetes for many years, we have been actually asking them to produce urine samples on at least a yearly basis because this is the early warning sign of kidney damage in someone with diabetes. We also know that there are people with hypertension, high blood pressure and other conditions who will also start to leak albumin in the urine, and these people need extra special blood pressure control because we know that by treating blood pressure better we can reduce the strain on the kidneys and we can reduce the albumin going through into the urine. So it’s a very, very useful test. It’s not always a test that patients like to do, because people forget, but it is really important. It is as or even more important for some people than doing the blood test. And every year we would like to see our patients, we do blood tests, we do urine tests and obviously we check their blood pressure.

After you have had the test done then usually in my practice I would ask patients to contact the practice to see if I have left them a message about the results. Often the kidney function will be gradually declining. That is not necessarily anything to worry about. It’s the rate it is declining and the level it is at that matter. So I will perhaps leave them a message to say, ‘Your kidney function is the same as before, so it is not normal but it is what it was for you and it’s not getting worse.’ I might say, ‘The kidney function is a little worse’, but that would, in many ways what I would expect as people get older. Sometimes I ask people to come back and see me to talk about it because it’s often very difficult on the telephone to get over these concepts and to understand the exact level. I can also print them off a graph. I can show them what’s actually been happening to their kidney function so that I think it’s important that you, visual images are very good to help you to see what’s happening. But I would expect the graph to show a small decline. Sometimes it will actually show things going up and down because kidney function can improve a little and it can decline a little. So it’s not a smooth graph. It would be moving up and down, and again that’s what I would expect and wouldn’t be anything to worry about.

So most of my patients I would see perhaps once or twice a year about their kidney function, unless their kidney function is in the lower levels. And when it drops below 30 we call that chronic kidney disease Stage 4, and those people would have more check-ups and would perhaps be expected to go to the hospital.

The people with kidney function between 30 and 60 I would expect can be managed most of the time by a GP and a practice nurse within a practice as part of the practice chronic disease management programme and with regular check-ups there. So there aren’t any specific issues other than the things that we do anyway, which is about treating blood pressure and about lowering risk of heart disease, and about lifestyle advice, all of these things we should be able to manage quite usefully in Primary Care.

We only have very short consultations in general practice. It’s often very difficult to cram it in, and sometimes people feel afraid or anxious about telling a piece of information that they feel is going to open up a whole catalogue of questions and information. So what I think, this is where I think patient information is so important. So I would like to be able to say to someone that, ‘We’ve have had a blood test. It does show that you have got chronic kidney disease, which means that you’ve had several blood tests over a period of time which show that your kidney function has declined’. I would like to give them a simple explanation but also an information leaflet that they can take home with them, and then what I do is I print things off the computer and get people to come back, because they can’t take everything in and it, sometimes it is a bit of a shock and it is worrying, but I think if you can give them the information to read about, invite them to come back, then you’re answering questions not trying to deal with everything all in one go. And that’s how I would handle it. But we’re all different and we all do things in a different way. But for most of my patients I hope I will have told them and will have explained to them what the issues are, because if you understand the issues you realise it is not about dialysis, it’s about staying healthy for longer, and surely that’s what we all want.

So prescribing appropriately, prescribing the right medication – there a number of different families of anti… of blood pressure lowering drugs, and choosing the right ones needs to take into account what's happening to the kidney as well.

The other contribution that the GP can make is looking at the other parts of cardiovascular risk such as your cholesterol, your lipid profile as it's called, which needs to be treated if that’s abnormal, or needs to be treated if you’ve already had a heart attack or stroke and that actually also benefits the kidney. So it's a partnership between the things that the patients can do and the things that the GP can recommend.

And you mentioned that patients can do good things for their kidneys, for their kidney health by watching their diet, their weight and stopping smoking. What kinds of support could patients expect from their GP's surgery in helping them make those changes?

So it's supporting patients for behavioural change and I guess I'd put smoking at the top of the risk list. I mean, that’s part of the Duty of Care of the general practice. So many practices discharge that duty by having a practice nurse or a nurse practitioner who is particularly experienced at giving advice and support to patients. In relation to smoking cessation there now are very good nicotine replacement methods which, there is an additional benefit to talking about them and getting support and not just buying them across the counter. So a practice needs to be set up to give that support around smoking cessation; how to prescribe the nicotine replacement and needs to be in a position to give good advice on exercise; good advice on dietary choices. That should be part of modern general practice and, in my view, is just as important and there's some evidence for this, as prescribing the right medication.

What the additional benefit might be in terms of preventing further decline of kidney function – that needs to be part of a conversation. The patient may decide that actually it's not worth taking that additional drug for an additional say, you know, five percent reduction in their ten year risk of a heart attack or stroke and that to me seems a very legitimate decision on the patient's part.

I think one of the challenges here is that, for the majority of patients who have reduced kidney function, the effect of that isn’t a substantially increased risk of kidney failure down the line later in life. In fact the majority of patients don’t have an increased risk of kidney failure. The effect of their reduced kidney function is an increased risk of heart attack and stroke. So it becomes part of that larger conversation that we have for any patient who, say has raised blood pressure and doesn’t even have any issues with their kidney, about “is it worth taking this drug because you're feeling perfectly healthy Mr Smith, for the next twenty/thirty years depending how old you are, in order to reduce your risk of a heart attack or stroke by X percent?”. And that is the crux of the conversation because people with reduced kidney function aren't ill, any more than someone with raised blood pressure is ill, any more than someone at an increased cardiovascular risk is ill. These are healthy people. It's just that they do have an increased risk of a problem down the line and that has to be the content of a conversation. GPs are used to having that conversation because it's not how we were historically trained but actually it's where we have to be now and , so my hope is that patients who do have blood tests and urine tests showing protein which suggest that they have reduced kidney function, are able to have that kind of conversation with their GP before making a decision about taking medication.

Is there any dietary advice that would benefit patients with early stage CKD?

To, people think automatically because the kidneys get rid of end products, the proteins, that the things to avoid are proteins. My view for most of my patients is actually the big issue is to try and get them to lose weight, because if you can lose weight and get more active that will help lower your blood pressure, and that will help to protect your kidneys. The other big important factor is salt. So salt is in our diets. If you eat anything that has been made by somebody else it will have had salt put in it as a preservative, so bread, cereals, soups, anything that comes out of a jar or a tin will be full of salt. The highest salt product is actually Pot Noodle which has got the same salt content as sea water, so it can give you your salt intake and more for the day in a pot. So there is salt in every manufactured food, and the more salt we have the more that raises your blood pressure, and of course that is, will give you an adverse effect on your kidneys and your kidney function. It will cause you to, you could get puffy ankles and of course then what happens is people take water tablets and that has an, can have an effect on the kidneys. Best thing: avoid the salt in the first case. If you can do that, that will lower your blood pressure and that will help to keep you healthier. So I really focus on, on having a good, an optimum weight and to lower the salt in your diet. And that would be my focus, and just, just healthy eating. So fruit and veg, get out and about, be more active, because that is the best way to keep your kidneys healthy.

A lot of patients I have spoken to assume that there must be dietary advice out there that would help them, and they seem quite frustrated just by being told to eat healthily. They think information is being withheld for some unknown reason and that there must be something they can do beyond that.

Right. The big emphasis on kidney disease in the past has always been on those with more severe stages of kidney disease, so those who are coming to a stage when their kidneys need extra help and they might need dialysis. So all of the emphasis has been at that level and there have been some pretty horrible diets in the past for those people. They have different problems and they have much more severe problems about getting rid of these chemicals from the blood.

That isn’t the issue for our patients who have perhaps 50% kidney function. For them it’s not about the, helping their kidneys to work better by having less protein. For them it’s actually about helping their body to be more healthy and their cardio-vascular system be more healthy with the general advice we give for people who have got heart disease and high blood pressure, because at that level that’s the important thing for them. It’s their blood pressure and their cardiovascular system rather than thinking about the same dietary advice for people who have got much more severe stages of kidney disease.

I’d just also like to say a little bit about my role, because I am, part of my role as, other than being a general practitioner, is to be involved in work at the College of General Practitioners, because it was recognised that chronic kidney disease isn’t well understood in Primary Care, in general practice, and so the College has appointed myself as a Clinical Champion and I am also going to be having a Support Fellow, and the idea is to try and raise awareness for patients and for doctors about chronic kidney disease in Primary Care. We will also be developing educational materials, working with the patient groups, such as the British Kidney Patients Association and the NKF, about producing the right information for people in practice and, again, it is about making the patient the centre of their care and giving them the information that they need to help look after themselves better, and having that knowledge I think, I know knowledge is power but I think it is, it is power for people with chronic kidney disease and we need to try and get it right for you.

Your practice might be invited to be part of a National Audit, so again raising the quality of care. The HQIP, which is another national organisation, has funded an audit project throughout the UK. - Sorry - has funded an audit project which will take place in England and Wales and which your general practice may be involved in, and the idea is to help identify patients in the practices who have chronic kidney disease and to help look after them better. And the GPs will be given information about how that may best be done. And you may have a letter or see a poster up in the practice about this project, and you will be invited to feedback and ask about it. But all of these projects are working together to try and improve the care for yourselves and other people like you who have got chronic kidney disease.

Whereas before – and this may have been ignorance just on the part of us GPs – there was an ambiguity about that and we were getting results back from the laboratory based on the blood test, like the creatinine or the glomerular filtration rate calculation, which put the patient in a- in a category, potentially in a category of CKD - when in fact there wasn’t any evidence that treating that or managing that would make any difference to that patient. So it seemed from a GP perspective a sort of spurious labelling of patients, which was often the reason why GPs did not mention it to their patients as well.

And unfortunately they then mixed into that patients who had reduced kidney function and leaking protein, so there was a sort of blurring of the boundaries. And I think that that caused the GPs to – not – let’s put it diplomatically - not to prioritise the issue of CKD. I do think with the new guidance there is a real focusing on those patients who do potentially have a problem, and where there is some evidence that managing it, particularly through blood pressure, is going to make a difference.

So this reaction on the part of GPs to over-diagnosis and if you like over-medicalisation of normal variation will I hope be a thing of the past. But it’s a challenge to general practice to try and respond appropriately to this problem. And I guess to temper the enthusiasm of specialists. And this is not just true for kidney specialists - all specialists are really enthusiastic about what they do. All specialists are worried about failure to diagnose, and that’s true if you’re an oncologist or a heart specialist or a stroke specialist or a kidney specialist. So general practice is a place where things are missed. And there is pressure on GP to not miss, and unfortunately that sometimes gets translated into a pressure to over-diagnose. And so GPs have this important role of trying to temper – to temper that enthusiasm. And I think the new NICE guidelines strike a good balance between the sort of- the generalist and the specialist perspective.