NICE Guidance for GPs on Primary Hyperparathyroidism 

Prof Neil Gittoes

Disclosures

May 26, 2020

Primary hyperparathyroidism is a common condition. It can be difficult to diagnose and difficult to follow-up too, particularly in the setting of primary care. Prof Neil Gittoes looks at the National Institute for Health and Care Excellence guidelines.

Adapted from Univadis from Medscape.  This transcript has been edited for clarity.

My name is Neil Gittoes. I am a consultant and honorary professor of endocrinology and I’m clinical lead for the NICE guideline looking at primary hyperparathyroidism (PHPT). The guidelines for PHPT are important because there is quite a significant variation in practice from person-to-person, from clinician to clinician, and there are problems around the diagnosis, identifying the condition, and knowing when surgery might be required.

The presentation is with raised serum calcium levels, and this is due to one of the four parathyroid glands that sit in the back of the thyroid gland becoming enlarged. Very rarely more than one gland can become enlarged. The only definitive way of getting rid of the problem is with successful surgery to remove the adenoma.

Can of Worms

PHPT often presents these days with a coincidental blood test finding of a raised blood calcium.

You can imagine the scenario. You have your blood test, your calcium's high - just because you have had your cholesterol checked. And then someone says to you, “So how have you been feeling though? Bit off colour? Bit tired? Bit achy?”

It's that thing, often secondarily, when someone tells you, there’s something not quite right in your biochemistry. But as a presentation, it is a can of worms, it really is.

Do we screen everybody who is feeling a bit off colour? If you keep coming back feeling not quite right, we say we'll check your calcium, it is cheap and cheerful. There is no harm in doing it.

The patient may have thirst, getting up in the night and passing lots of urine, and constipation. Those are some very clear features of raised calcium.

It is always worthwhile repeating the calcium tests more than once. Calcium measurement is tricky because it tends to be reported as total calcium, and an adjusted calcium, where you adjust for the albumin. The one to pay attention to is the adjusted calcium.

If on two occasions it is elevated, the next key step is to measure PTH (parathyroid hormone). PTH is your best friend.

PTH Suppressed?

If the PTH is suppressed, and I would put that at the top of my list, you should be thinking about a diagnosis other than PHPT, and within that list could potentially be malignant pathologies, so you really need to pay attention to that.

If the PTH is not suppressed, then pretty much you are in the territory of making a referral to secondary care, particularly if the PTH is above the mid-point of the reference range, the probability is that you are looking at a diagnosis of PHPT.

Patients often ask me, 'Because I have got this calcium problem, do I need to change the amount of calcium that I eat?', and the answer is 'no'. A healthy balanced diet, something that is absolutely mainstream, is the right thing to do. Don’t try to restrict your calcium, don’t try to take in more. Take  your vitamin D, if that is what you have been given as a supplement, but just have a normal diet.

Once the diagnosis of PHPT has been made, then referral into a secondary care environment is helpful. Then the key question is making sure you have got the right diagnosis and to then determine whether a curative procedure with parathyroid surgery should be employed or not.

Emergency treatment in PHPT is pretty unusual. Occasionally patients may present with extremely raised calcium, particularly if they become dehydrated. That is unusual and occasionally we perform early parathyroid surgery. But importantly, don’t just look at the numbers. If the calcium is 3.0 for instance and the patient is very well, and they have got PHPT, there is no requirement for emergency admission.

Secondary Care

Initial steps in secondary care once the patient has presented with query PHPT is to confirm the diagnosis and to look at the way the kidneys handle the calcium, so looking at urine calcium excretion. We would expect that to be either high or well within the reference range.

Once in a secondary care environment and using all the investigations we have mentioned to date, the next question is, do we think this patient will benefit from surgical intervention?

If we think surgery is a reasonable way forward then we perform some imaging investigations, starting with ultrasound because it is quick and easy with no radiation involved.

In addition to that, we check renal function as well, and then we would look for end organ disease, in other words, any long-term consequences of PHPT, and that would be done conventionally by using an ultrasound of the kidneys to look for stones, and using a DXA scan to look at bone density to see if there is an increased risk of fracture.

Surgery

Once a patient is referred to a surgeon, and the surgeon will have a discussion, that will take into account the imaging results that have been obtained. And then either a focused approach, where there is a more targeted surgical approach to the adenoma, if there is a single adenoma. However, if things are a little more complex, or if it is difficult to identify the adenoma, then an open approach with a slightly longer scar to examine all four glands would be performed.

The procedure may be done the same day, or with an overnight stay in some settings. We often say that for recovery, perhaps 2-4 weeks before patients should be doing too much following successful surgery.

Immediately after parathyroid surgery, we would check the calcium level, and the PTH levels fall quickly, so the calcium falls quickly. So we know pretty much straight away whether parathyroid surgery has been successful.

What I would do in my role is to see patients 3-6 months post surgery as well, and that is what we use as a definitive, if you like, cure point. Checking the calcium at that point, looking for any evidence. Do we need to do any more about underlying bone disease? Are there stones that need to be managed? So that’s then a separate issue, more getting into the longer-term management.

Non-surgery Patients

If the patient has not gone forward for parathyroid surgery, with the diagnosis of PHPT, it does not mean that at any point in the future they may not be a candidate for surgery. Keeping an open mind is important, and monitoring as well. So checking the blood calcium and kidney function on at least an annual basis is important, or in-between times if the patient is unwell.

Keeping an eye on bone density and fracture risk with DXA scan every 2-3 years, and if you are concerned that a renal stone may be brewing, then an ultrasound of kidneys is important as well.

There is a sub-group of patients where perhaps parathyroid surgery isn’t feasible and their calcium level may be high to the extent that we would think about introducing a calcium emetic drug called cinacalcet, but that tends to sit very much in the realms of secondary or tertiary care.

Key Points

PHPT in pregnancy is difficult and simple all in one. And my simple advice would be, if you have a patient with PHPT who is pregnant, refer to the specialist MDT. This is rare and difficult and needs to be managed on an individual case basis.

Within the NICE guideline, some of the key points we have tried to highlight is around the importance of measuring the calcium on more than one occasion.

It is really important if you have got sustained hypercalcaemia to measure the PTH and to remember that if that PTH is suppressed to think about an alternative diagnosis. But to refer those patients up who have PTH well within the reference range, to be considered for potential parathyroid surgery.

Developing the Guidelines

The guideline development group incorporated GPs, specialists, surgeons and patients. So having that open dialogue and communication with patients, and as well linking back to what we can offer with long-term management of these patients with shared care, keeping communication open as well between primary and secondary care so that we are all speaking the same language for what can be a chronic disease if we don’t cure it at the time of surgery.

The evidence and the data around this rather complex area are not full, and not complete, so there is a lot of pragmatism and we spent a lot of time making these clinically useful, as much as we can.

The idea of these guidelines are to be very much user friendly, to be used in the field, so that you can channel patients and determine at which points they should be referred into the system.

But as I say, this is a very clinically focused and hopefully clinically useful tool that’s meant to be used on a day-to-day basis, because at the end of it, this is a very common presentation.

 

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