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Referral Guidance: Thyrotoxicosis or Hyperthyroidism |
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University
Hospitals of
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Department
of Diabetes & Endocrinology Leicester Royal
Infirmary, |
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Thyrotoxicosis : About the Condition |
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Definition |
· Thyrotoxicosis occurs when blood levels of thyroid hormones (T4 and T3) rise above the normal range. TSH is suppressed to undetectable levels except for extremely rare causes. · “Subclinical hyperthyroidism” or “Autonomous thyroid function” describes the state where TSH levels are subnormal but fT4 and fT3 remain in the normal range. ·
Aetiology (in order of frequency) may be autoimmune
with antibodies which stimulate the TSH receptor ( |
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Symptoms |
· Patients with thyrotoxicosis may complain of some or all of weight loss despite a good appetite, heat intolerance, sweating, tremor, palpitations, anxiety, diarrhoea, thirst and itching. · Patients with Graves’ disease may complain of soreness, watering or prominence of the eyes. · Patients with borderline overactivity may notice few or no symptoms, but are at increased risk of cardiac arrhythmia |
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Signs |
· Tremor, Goitre, Sweaty hands · Tachycardia, Full pulse, AF (particularly in elderly) · Lid retraction or ‘stare’ with all causes. Other features of thyroid-associated ophthalmopathy in Graves’ disease |
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Investigations |
· Free T4 levels are above normal · TSH level is undetectable (<0.05) · Free T3 levels are not routinely measured but are also above normal · A positive Thyroid peroxidase (TPO) antibody may confirm the diagnosis of autoimmune thyroid disease · If TSH is undetectable and free T4 is normal, then a free T3 level is essential to exclude T3 toxicosis (but the laboratory may not perform this test unless specifically requested) · High free T4 levels with normal TSH may be due to assay artefact, thyroid hormone resistance or pituitary TSHoma (further specialist investigation is essential prior to treatment) |
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Other factors |
· Amiodarone may precipitate thyrotoxicosis · Thyroiditis (including post-partum thyroiditis) may present with a thyrotoxic phase |
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Thyrotoxicosis: When to Refer? |
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Referral Recommendations |
· We believe that all patients with frank thyrotoxicosis will benefit from review by a specialist endocrinologist, in order to establish diagnosis and aetiology, discuss treatment options and agree a long-term treatment strategy. This is in line with previously-published national guidance. · Whilst carbimazole has sometimes been managed within primary care, radioactive iodine and surgery are only available in secondary care. · For patients undergoing a course of carbimazole (or PTU), or for monitoring remission, relapse after treatment and progression to hypothyroidism, we are able to offer advice to patient and GP via the Thyrotoxicosis Shared-Care Scheme, whilst minimising visits to hospital. |
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Urgent Referral |
· Most patients with symptomatic thyrotoxicosis can be commenced on treatment with carbimazole (and often propranolol) at the point of referral, prior to routine clinic review. This achieves more rapid restoration of the euthyroid state than starting treatment later at an urgent clinic visit. · Very severe thyrotoxicosis rarely presents as ‘Thyroid Storm’ – this is a medical emergency and should be discussed urgently by phone or email. · Urgent outpatient referral may be appropriate in a symptomatic patient where there is diagnostic uncertainty or doubts about most appropriate therapy. This includes thyrotoxicosis in patients who are pregnant. |
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References or Guidelines |
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Thyrotoxicosis
Shared-Care Scheme outline treatment protocol |
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Which Clinic or Choose & Book Service? |
· A “Thyrotoxicosis Shared-Care Service - Endocrinology - LRI - RWE” referral will enrol suitable patients in the Thyrotoxicosis Shared-Care Scheme and book an appointment on the list of the Endocrine Nurse Practitioner in one of our clinics. This is appropriate for clear-cut thyrotoxicosis where a course of carbimazole is envisaged, or where counselling on choice between treatments is needed. We will send information to the patient and advice on dosage before and after first clinic attendance. · An “Adult Endocrinology Service - Endocrinology - LRI - RWE” referral will book an appointment on any of medical lists in clinics at Leicester Royal Infirmary where endocrine patients are seen. This may be appropriate where a medical opinion on diagnosis or choice of treatment is required. It will not automatically enrol the patient in the shared-care scheme. · A “Joint Surgical-Endocrine Service - Endocrinology - LRI - RWE” referral may be appropriate if the patient has considered all options and definitely wishes to proceed to thyroidectomy – but unlikely to be appropriate otherwise. · Direct referral to the radioactive iodine treatment service may become available in future |
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Thyrotoxicosis: What to do before a
hospital appointment? |
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Additional Investigations |
· Check TPO antibodies if not already known · Check free T3 level if fT4 is normal and TSH suppressed · Consider thyroid ultrasound if clinically nodular goitre and no other signs of Graves’ disease (but we can also arrange this in clinic) |
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Treatment prior to specialty appointment |
· If diagnosis of thyrotoxicosis is clear cut, then usually it is appropriate to begin treatment with carbimazole at the same time as referral. · Repeat TFTs at time of starting carbimazole (to exclude transient causes). · For fT4 >30pmol/L we suggest carbimazole 40mg once daily for 1 month and then reduce to 20mg once daily · For fT4 25-30pmol/L we suggest carbimazole 20mg once daily · Exceptions include patients with mild symptoms or borderline tests where direct progression to radioactive iodine is being considered. · Half life of T4 in blood is approx 1 week and symptoms run at least 1 week behind the prevailing thyroid function tests. · Propranolol (40mg-80mg t.d.s) can give symptomatic control of many symptoms whilst awaiting response to carbimazole |
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How to manage the patient if you do not refer |
· Asymptomatic patients with suppressed TSH and normal fT4 and fT3 may be monitored in primary care with thyroid function tests at increasing intervals. Treatment of such patients has been advocated, but there is no international consensus whether this is necessary or effective. · A few GPs initiate and manage a course of carbimazole treatment without referral to the specialty clinic. In our experience, control in these patients is frequently erratic and not precisely monitored. We believe that the Thyrotoxicosis Shared-Care Scheme offers a mechanism to achieve better control whilst minimising hospital visits. |
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Patient Information |
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Thyrotoxicosis: What will we do in the
specialty Endocrinology clinics? |
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Outline of Management |
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Consider differential diagnosis ( · Discuss treatment options with the patient and reach a mutually-agreed long term treatment plan. We will normally recommend: · Carbimazole 18 month course – for Graves’ disease in first toxic episode · Radioactive iodine – for nodular thyroid disease with negative TPO Ab or for relapse of Graves’ disease (or by patient choice) · Surgery – for large goitre causing pressure symptoms or intolerance of medical therapy with contraindication to RAI (or by patient choice) · Long term carbimazole: by patient choice even for non-remitting aetiologies or in cases of relapse. · Monitor thyroid function and provide dose adjustment advice in patients on carbimazole/PTU, and in monitoring remission after carbimazole or radioactive iodine. · Management of other aspects of Graves’ disease, including eye problems. · Liaise with other speciality services including ophthalmology (for thyroid eye disease), endocrine surgery, radiology and radioisotopes service. |
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Treatment options |
· Carbimazole or PTU (controls TFTs and allows spontaneous remission). · Radioactive iodine (effective for all causes; radiation safety regulations can be inconvenient; hypothyroidism likely long-term). · Near-total thyroidectomy (effective for all causes; very appropriate for large goitre; hypothyroidism inevitable post-op; recurrence can occur long-term; operative risks). |
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Follow up plan |
· In most cases (for patients in Leicestershire with TFTs in LRI lab) monitoring will be undertaken via the Thyrotoxicosis Shared-Care Scheme (TSC). Bloods are recommended, and results reported, initially every 8 weeks and then at increasing intervals in the long term. · For patients in TSC, clinic appointments will usually be arranged annually for patients who continue to take carbimazole · Patients who are on no treatment will not usually be seen in clinic although we will continue to advise on TFTs via TSC. · Patients unwilling or unable to be included in TSC will be reviewed at repeated outpatient visits at increasing intervals whilst they remain on treatment. |
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Long term monitoring |
· Patients who have been thyrotoxic typically require long term monitoring of their thyroid function. We are happy to supervise this – usually via TSC: · Monitoring of control of TFTs and dose adjustment whilst patients remain on carbimazole/PTU. · Monitoring of remission/relapse following treatment. · Monitor for long-term development of hypothyroidism (particularly after radioactive iodine |
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Referrals to all clinics can be arranged
via Choose and Book. We are also happy to receive
written referrals and will allocate patients to the most appropriate clinic
slot. If
you consider that your patient needs urgent assessment, then all consultants
are happy to discuss directly (by phone or email) and arrange prompt review
if appropriate. In
the case of a real or potential endocrine emergency we will almost certainly
be happy to see the patient the same or the next working day whether or not a
clinic is available. Contact the endocrinologist: By email: endocrinology@uhl-tr.nhs.uk or individual
consultant emails By phone: 0116 258 6140 and ask to talk to one of the
consultants Fax: is less reliable and usually no faster than written
mail |