The Exeter Guidelines on Thyroid Disease provide comprehensive guidance on all aspects of this common group of conditions, as Dr Tim Harlow explains


   

Thyroid disease is reasonably common, and largely presents and is managed in general practice. GPs also have access to most of the relevant examinations for the management of thyroid disease.

Until recently it has been hard to find good authoritative guidelines on dealing with this common group of conditions. Last year, however, that all changed with the launch of the Exeter Guidelines on Thyroid Disease (see Figure 1) which have been welcomed as an excellent addition to our practice guideline portfolio.

Figure 1a: Front page of the Exeter Guidelines on Thyroid Disease
exeter guidelines
Figure 1b: Reverse side of the Exeter Guidelines on Thyroid Disease
exeter guidelines

These guidelines have been developed by a representative group of specialist endocrinologists, clinical biochemists and GPs. This broad base shows in the acid test for guidelines – they are still on the desk and being used nearly a year later.

An astonishing amount of information has been crammed onto just one laminated double A4 sheet, including a brief discussion of the literature and the strength of the evidence.

 

Diagnosis is well covered. We all know the classic textbook descriptions of thyroid disease and how rarely the patient in our surgery fits these ideals. Sensibly this is not discussed and the guidelines pitch straight into interpretation of the biochemical tests.

All laboratories are different, and it is vital to have local references. Where there is an interplay of three variables – thyroid-stimulating hormone (TSH), free tri-iodothyronine (T3) and thyroxine (T4) – to consider in the management, I find the clear explanations in the guidelines most helpful.

It is useful to be reminded of conditions such as pregnancy and oral contraceptive use where there can be increased total thyroxine due to increased thyroid-binding globulin and yet no thyrotoxicosis.

 

Thyrotoxicosis is dealt with first. Different options are discussed, depending on the age of the patient, whether it is a first or recurrent episode of disease, and the cause of the disease.

My management has been changed by these guidelines. I used to use the BNF policy of gradual reduction in carbimazole, but now use the 'block and replace' policy advocated here. The resulting stability seems better, especially in younger people. There are also clear guidelines for the addition of thyroxine in this situation.

The criteria for specialist referral are discussed and no-one would argue with the need for specialist management of thyroid eye disease or where the patient specifically requests it.

I am less sure that uncomplicated first cases need to be offered an endocrinology opinion. Specialist outpatient clinics do seem much readier to discharge patients back to primary care than a few years ago, so maybe that is reasonable.

The clear guidance on 3-monthly tests for 2 years after stopping carbimazole is good. Before reading the guidelines I might not have performedkthyroid function tests 6-monthly thereafter, but the guidelines have sharpened my practice in this area.

I confess to having been a bit hazy about the indications for surgery or radioactive iodine as opposed to medical treatment, so the discussion of this topic is useful.

 

Most GPs find hypothyroidism easier to treat, with its slower onset and many more patients having this chronic condition. Again the guidelines contain excellent advice about diagnosis.

The section on subclinical hypothyroidism has given me real help in dealing with this area.

I was fascinated to see that up to half of those with normal T4 and marginally elevated TSH will feel better on thyroxine. It is useful to be reminded that up to 20% of them will progress to overt clinical hypothyroidism. I always had a slight twinge of guilt when trying such patients on thyroxine and it was a relief to see some justification for this practice!

There is a wise reminder of the perils of starting ischaemic heart disease patients on thyroxine, together with a useful suggestion to consider a beta-blocker.

 

Prognosis is dealt with, especially with regard to thyroiditis. Few GPs in primary care would be alert to thyroiditis perhaps, but these guidelines will raise my index of suspicion.

For the first time in 22 years of medical study, I almost understand sick euthyroid syndrome, thanks to a single masterly paragraph in these guidelines.

There is an important warning about the differentiation of secondary hypo-thyroidism from other problems. Referral to the endocrine clinic for patients in whom this is suspected is mandatory. Premature treatment may well precipitate an adrenal crisis and there is clear guidance about this.

 

There are two related benefits of guidelines which we sometimes forget. First, the obvious one that we are rarely as fully up to date and practised in slightly unusual conditions such as thyroid disease as we like to think. Second, it can be a great boost for patients to see that their condition is well recognised and their doctor is following accepted practice.

In medicine the ideal of seamless and coherent primary/secondary care seems at times optimistic, but these guidelines make it much more likely.

If referral to secondary care becomes needed then we have all been working in the same direction, and there is less risk of, for instance, using inappropriate doses of drugs or unnecessary duplication of investigation.

 

At the end of the guidelines there is a list of phone numbers and clinic times, which is so useful in local guidelines and makes appropriate referral so much easier. There is even a built-in review date so we know exactly how up to date the information is.

Anyone looking for a good template from which to produce local guidelines for disease management should take a long hard look at these. My only worry is how the endocrine clinic will cope with the thousands of requests for copies that may follow if these truly excellent local guidelines become widely publicised.

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Guidelines in Practice, April 2000, Volume 3
© 2000 MGP Ltd
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