Presented by Professor Neil Gittoes, the Clinical Lead for the NICE Guideline on Primary Hyperparathyroidism. He is a consultant and Honorary Professor of Endocrinology at the Institute of Metabolism and Systems Research, University of Birmingham.
Primary Hyperparathyroidism is a common condition. It can be difficult to diagnose and difficult to follow up to, particularly in the setting of primary care.
My name is Neil Gittoes, I am a consultant and professor in endocrinology and clinical lead for the NICE guideline looking at PHPT. The guidelines for PHPT are important because there is quite a significant variation of 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 glands becoming enlarged, very rarely more than one gland becoming enlarged. The only definitive way of getting rid of the problem, is successful surgery to remove the adenoma.
PHPT often presents these days with a coincidental blood test findings of a raised blood calcium.
You can imagine the scenario. You have had your blood test. Your calciums high, just because you have had you cholesterol checked and then someone says to you. So how have been feeling though. Bit off colour. Bit tired. Bit achy. So it is that thing that often secondarily when someone tells you, you are 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 will 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, passing lots of urine. Constipation. Those are some very clear features of raised calcium.
So it is always worthwhile repeating the calcium 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.
And if on two occasions it is elevated, the next key step is to measure PTH. PTH is your best friend.
If 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, and 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.
So 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 is something that is absolutely mainstream and is the right thing to do. Don’t try to restrict your calcium, don’t try to take in more. Keep taking your vitamin D if that what you have been given as a supplement and just have a normal diet.
So once the diagnosis of PHPT has been made, then referral into a secondary care environment is helpful and then the key question is to make sure you have got the right diagnosis and to then determine whether UNKOWN procedure with para thyroid surgery should be employed or not.
Emergency treatment with 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 Para thyroid surgery but importantly, don’t just look at the numbers. If the calcium are 3.0 for instance and the patient is very well, and they have got PHPT, there is no requirement for emergency admission.
Initial steps in secondary care once the patient has presented with query PHPT is to confirm the diagnosis and to look at the ways the kidneys handle the calciums. So, looking at urine calcium excretion. We would expect that to be either high or well within the reference range.
So once in a secondary care environment and using all the investigations we have mentioned today, the next question is, do we think this patient will benefit from surgical intervention. If we think surgery is a reasonable way forward, then the performance of 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 looking for stones and using a DXA scan looking a bone density to see if there is an increased risk of fracture.
Ok, so once a patient is referred to a surgeon and the surgeon will have a discussion and will take into account the imaging results that have been obtained and then either a focused approach whether it be 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 4 glands would be performed.
Procedure may be done same day of overnight stay in some settings. They often say that in recovery, often 2-4 weeks before patients should be doing too much following a successful surgery.
So immediately after Para thyroid surgery, we would check the calcium levels and the PTH levels fall quickly, and the calcium falls quickly so we know pretty much know straight away whether Para thyroid surgery has been successful.
So 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 like cure point. Check the calcium at that point, check for any evidence. Do we need to do any more about underlying bone disease. Are there stones that need to be managed. So that is a separate issue, more than getting into the longer term management.
So if the patient has not gone for para thyroid 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 so keeping an open mind is important. Monitoring as well. So checking the blood calcium and kidney function on an annual basis is important or 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.
There is a sub group of patients where perhaps para thyroid surgery isn’t feasible and there calcium levels may be high to the extent that we may think about using a drug called Cinacalcet but that tends to sit very much in the realms of secondary or tertiary care.
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.
So 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, think about an alternative diagnosis. But to refer those patients up who have PTH well within the reference range, to be considered for potential para thyroid surgery.
So the guidelines were developed. The guideline group incorporated GP’s, 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 opens 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 spend a lot of time making these clinically useful as much as we can so the idea of these guidelines are to be very much user friendly, used in the field so that you can channel patients and determine which points they should be referred into the system. But as I say, this is a very clinically focused and hopefully clinically useful tool meant to be used on a day to day basis because at the end of it, this is a very common presentation.