surgical conditions thyroidectomy endocrine dysfunction - management thyroidectomy total...

SURGICAL SURGICAL CONDITIONSCONDITIONS

THYROIDECTOMYTHYROIDECTOMY

ENDOCRINE DYSFUNCTION - ENDOCRINE DYSFUNCTION - MANAGEMENTMANAGEMENT

THYROIDECTOMYTHYROIDECTOMY

TOTAL THYROIDECTOMY – THYROID REPLACEMENT IS REQUIRED

SUBTOTAL THYROIDECTOMY – USE SERUM THYROID LEVEL AS AN INDICATOR

THYROIDECTOMY - MEDICATIONTHYROIDECTOMY - MEDICATION

THYROXINE REPLACEMENTTHYROXINE REPLACEMENT

HALF LIFE OF THYROXINE IS FEW DAYS, THEREFORE CAN WAIT TILL STARTING RX.

DOSE (L-THYROXINE) : 0.15 – 0.2mg dly


TSHTSH

USED AS SUPPRESSION FOR…

1)NON-TOXIC GOITER

2)OR IF SUBTOTAL THYROIDECTOMY

3)FOR TOTAL THYROIDECTOMY FOR THYROID CA (SELECTED CASES)

DOSE : 0.2 – 0.4mg dly


PROPANOLOLPROPANOLOL

IF PT WAS GIVEN PRE-OP PROPANOLOL, ADVISABLE TO CONTINUE 2 -3 DAYS POST OP.


HYPOPARATHYROIDISMHYPOPARATHYROIDISM

Hypoparathyroidism can occur post surgery.

More likely in extensive dissection for diffuse nature or malignancy (esp. radical neck dissection)


THYROID STORMTHYROID STORM

Can occur as a complication post surgery.

Manage precipitating factors

Reduce synthesis and release of thryoid hormones.

Reduce peripheral conversion of T4 to T3.

MX OVERVIEWMX OVERVIEW

THYROIDECTOMY – THYROID STORMTHYROIDECTOMY – THYROID STORM

SUPPORTIVE MEASURESSUPPORTIVE MEASURES

These pts are hypermetabolic and need more fluids electrolytes and glucose.

Bring down fever (but don’t use salicylates – they diplace thyroid hormones from their binding prots.)

Plasma exchange as last resort – not proven to work


B-ADRENERGIC BLOCKERSB-ADRENERGIC BLOCKERS

Antagonises the effect of thyroid hormones.

Decreases the

hypersensitivity to

cathecholamines.

FUNCTIONSFUNCTIONS



Drug of choice as it also inhibits peripheral conversion of t4 to t3

It promptly treats the tachycardia, fever, hyperkinesis & tremor

PROPANOLOLPROPANOLOL

IV doses of 0.5mg with cardiac monitoring up to 10mgGive more 4-6 hrly

THYROIDECTOMYTHYROIDECTOMY - THYROID STORM - THYROID STORM


B1 selective agents not as good – do not inhibit T4 to T3

Use when Propanolol contra-indicated.

OTHER AGENTSOTHER AGENTS

Esmolol 250-500micg/kg bolus followed by 50-100mcg/kg/min.

(Diltiazam also good in reducing pulse rate.)

THYROIDECTOMY - THYROID STORMTHYROIDECTOMY - THYROID STORM

CORTICOSTEROIDSCORTICOSTEROIDS

Given because of the relative deficiency.

Also used beacue they inhibit periph. conversion T4 to T3.

Hydrocortisone 100mg ivi 6hrly or Dexamethasone 5mg ivi 12 hrly


THIONAMIDESTHIONAMIDES

PropylthiouracilNo parental form avail. – and in thyrotox, GI absorp is downRapid onsetFunction – blocks iodination of Tyrosine and inhib of periph. Conversion (T4 – T3)Dose: 100mg loading then 100mg 2 hrlyMethimazoleSlower onset, but longer action.Does not inhibit periph. Conversion (T4-T3)Dose: 100mg bolus then 20mg 8hrly

CarbimazoleIt is metabolised to methimazole

For all…..

Transient leukopaenia (20%). Agranulocytosis is rare


IODINEIODINE

In large doses, it inhibits synthesis and release of thyroid hormonesGive 1 hr after thioamidesPreps are Lugol’s iodine(oral), potassium iodide, sodium iodideDose: Sodium iodide 1g ivi 12hrly or equiv oral dosesIodine containing contrast media are very good as they are more potent inhibiters of periph conversion.


LITHIUM CARBONATELITHIUM CARBONATE

Used for patients allergic to iodine. Similar action

Dose: 500-1500mg dly.

Drug monitoring of Lithium.


DIGOXINDIGOXIN

Use if AF or heart failure present.

Larger than normal doses because of the high BMR


AMIODARONEAMIODARONE

Controls Arrythmias

Inhibits peripheral conversion of T4 to T3.

THYROIDECTOMY – MORE THYROIDECTOMY – MORE COMPLICATIONSCOMPLICATIONS

MYXOEDEMA COMAMYXOEDEMA COMA

Thyroid hormonesT3 best idea. Dose: 20mcg/d.T4 not good because periph. conversion is decreased.SteroidsGiven because these pts have impaired glucocorticoid response to stress., or co-existant adrenal insuff. (Schmidt’s syndrome)Dose: Hydrocortisone 200-300mg/d

SupportiveThese pts have reduced response to hypoxia and hypercarbia, and decreased GCS, so ventilation often required.Warm to treat hypothermiaRx hyponatraemia, hypoglycaemia

PARATHYROIDECTOPARATHYROIDECTOMYMY

PARATHYROIDECTOMYPARATHYROIDECTOMY

INTROINTRO

Adenoma and hyperplasia. Removal of multiple glands usually with hyperplasia.

Transient hypopara. after gland removal.Suppression of normal glands

If hypocalcaemia occurs within the first 12-18 hrs, then it is likely to be severe.


CALCIUM REPLACEMENTCALCIUM REPLACEMENT

Mild hypocalcaemia – just watch

Mild hypocal with tingling of lips, fingers, toes – oral therapy.

Tetany – IVI Calcium

NB – pts on digitalis are more susceptible to arrthmiasVit D is usually withheld for 4 – 6 weeks, unless it is difficult to maintain the Ca.Parathyroids usually recover within this period.


HYPOCALCAEMIA – GENERAL HYPOCALCAEMIA – GENERAL ASPECTSASPECTS

Generally a problem in 70-90% of ICU patients.

IVI calcium…Two forms. Chloride and gluconate.Diff. btw 2 is the amount of elemental ca avail at equiv volumes

Avoid rapid admin – causes nausea, flushing, headache arrythmias.Dose – 100mg bolus, then 1-2mg/kgIf not coming up with IVI replacement – consider Mg deficiencyCalcitrol is usually used for the more chronic conditions.

ADRENALECTOMADRENALECTOMYY

ADRENALECTOMY ADRENALECTOMY

ADRENALECTOMY – ADRENALECTOMY – INDICS.INDICS.

Bilateral adrenalectomy most often done for disseminated breast CA.Old days, done for HPT. Now medical mx is good enoughHyperplastic states from pituitary tumoursNeoplasms

ADRENALECTOMYADRENALECTOMY

MANAGEMENTMANAGEMENT

Treat complications - bleeding, pneumothorax, esp if 12th rib is resected.

Ileus following retroperitoneal dissection.

Treat Adrenocortical Insufficiency…


ADRENOCORTICAL INSUFFICIENCYADRENOCORTICAL INSUFFICIENCY

Be aggressive. Start even before blood levels available.

Anticipate who will need – Adrenalectomy, pt’s who are supressed from steroid therapy, pt’s with adrenal or pituatary disease.

Do not replace as a ‘standard’.


ADRENOCORTICAL INSUFFICIENCYADRENOCORTICAL INSUFFICIENCY

Start replacement with induction of anaesthesia.

Start with Dexamthasone 10mg IVI, together with ACTH 0.25 ivi (synacthen)Continue steroid replacement with Hydrocortisone 100mgiv 6-8hrly. Taper. Taper then to oral.

Hydrocortisone has sufficient mineralocrticoid component.


GENERAL MEASURESGENERAL MEASURES

Avoid opiates and sedativesCorrect electrolyte and glucoseFluid balanceEcg monitoringTreat shockFluids need to be aggressive initially

PHAEOCHROMOCYPHAEOCHROMOCYTOMATOMA

PHAEOCHROMOCYTOMAPHAEOCHROMOCYTOMA

GENERALGENERAL

Tumour of the Adrenal Medulla

No other surgical problems for consideration in the adrenal medulla


PROCEDURES DURING PROCEDURES DURING SURGERYSURGERYPrep for surgery: alpha-adrenergic blocker

as soon as dx madePhenoxybenzamine 10-100mg b.d. for at least 3 d before Sx.Phentolamine (1-5mg) can be used for immed effect if the BP rises during sx Approp. inotropes and volume expanders to be used if BP drops after removal. Propanolol can be used pre, intra, and post op to prevent and Rx cardiac arrythmias. Oral or IVI (10th the oral dose).


POST SURGERYPOST SURGERY

Few days post Sx: urinary Vanillymandelic Acid and Cathecholamines to verify proper removal of tumour.

If bilateral adrenalectomy was done – consider corticosteroid replacement.

PITUITARYPITUITARYSURGERYSURGERY

PITUATARY SURGERYPITUATARY SURGERY

INTROINTRO

ACTH replacement must be given as described

Remember, with pharmacologic doses of steroids, underlying diabetes may be unmasked, and DKA etc must be managed.


ADH DEFICIENCYADH DEFICIENCY

This occurs unless the stalk is left intact, there may be no deficiency.

Triphasic response to sx….1)Immed post sx – polyuria and polydipsia –

4 to 5 days2)Intense anti-diuresis for 6 days3)Permanent poyuria and polydipsia (DI)

Phase one is due to damage to hypothalamus tissue and hormone not released.

Phase 2 is due to degeneration of hormone laden stores. Fluid admin during this phase will not induce the usual diuretic response.


ADH DEFICIENCYADH DEFICIENCY

During polyuric phase – watch fluid balance and electrolytes carefully.

DDAVP is treatmentrx of choice.

MANAGEMENTMANAGEMENT

Rx with ADH to decrease urine to normal values, withan increasein specific gravity.

NON-NON-SURGICAL SURGICAL

ISSUESISSUES

NON-SURGICAL ISSUESNON-SURGICAL ISSUES

HYPERGLYCAEMIAHYPERGLYCAEMIA

Hyperglycemia is a common metabolic feature of severe stress and is becoming recognized as a harbinger of the severity and outcome of illness.

The effects of counterregulatory hormones and pro-inflammatory cytokines predominate as a cause

Reversing hyperglycemia and insulin resistance reduces mortality

INTROINTRO



Trials have shown that aggressive treatment of hyperglycemia has a positive impact on immune recovery and the recovery from an MI

One study: Mortality was decreased by 34% in a surgical ICU by “clamping” the glucose level between 4.4 and 6.1 mmol/L

Insulin may have anti-inflammatory properties – but achieving normoglycaemia more important than insulin dose.

INTRO - CONTINUEDINTRO - CONTINUED



BBA’s relieve Stress Hyperglycaemia, thus implicating cathecholamines to the disorder.

Metformin particularly useful in SH. It has antihyperglycemic effects via suppression of glucose production of the liver as well as having antioxidant properties – but beware lactic acidosis

INTRO - CONTINUEDINTRO - CONTINUED

GROWTH GROWTH HORMONEHORMONE


GROWTH HORMONEGROWTH HORMONE

Despite aggressive nutritional support, critically ill patients remain catabolic with continued nitrogen loss.

GH supplementation has salutary anabolic effects in stressful conditions, but is poven to increase risk of mortality

GH replacement: If GH low, can be replaced with recombinant GH- appears safe

INTROINTRO


GROWTH HORMONEGROWTH HORMONEDELITARIOUS EFFECTSDELITARIOUS EFFECTS

Oedema

Insulin resistance

Exacerbated microvascular injury in the face of sepsis

Hyperglycaemia

Induces hepatic enzymes

HPA HPA INSUFFICIENCINSUFFICIENC

YY

HPA INSUFFICIENCYHPA INSUFFICIENCY

INTROINTRO

Adrenal insufficency occurs in 20% of ICU pts

Induced by sepsis, hypovolaemia, stress, drugs

Both high and low cortisol levels assoc. with poor prognosis.

Higher levels assoc. with higher APACHE and SOFA scores = poorer prognosis


EXAMPLESEXAMPLES

Cortisol > 1200 nmol/l in sepsis and resp failure.

Cortisol > 745 nmol/l in ruptured AAA.

A ‘normal’ level for ICU patients cannot be defined.

Use Synacthen and ACTH test.


CORTISOL SUPPLEMENTATIONCORTISOL SUPPLEMENTATION

Physiological doses of glucocorticoids of 300 mg per day leads to supraphysiological circulating cortisol levels

In a multicentre trial, septic pts given high dose cortisol – higher death rate than placebo group.


CORTISOL SUPPLEMENTATIONCORTISOL SUPPLEMENTATION

Concept of “relative adrenal insufficiency” and “low-dose” (ie, 100 to 300 mg per day) corticosteroid therapy.

Initial trials showed promising trends in subgroups of patients with sepsis.

The beneficial effects were restricted to improvements in hemodynamics and a reduction in the need for vasopressor therapy.


GENERAL CONCEPTSGENERAL CONCEPTS

The beneficial effect of steroids remains unproven, and a conservative approach is more prudent.

Clinician must rely on a clinical assessment of the severity of the stress, (evaluate misleading symptoms) to estimate the adequacy of the measured cortisol.

Clues of adrenal dysfunction, such as unexplained eosinophilia


GENERAL CONCEPTSGENERAL CONCEPTS

Certain conditions - TB, Meningitis, Typhoid fever, and PCP - the use of glucocorticoids appears less controversial

Can be considered in selected high-riskpatients, predominantly in septic shock patients, while awaiting confirmatory results of HPA testing.

Steroid therapy should be stopped if results of HPA testing become available and do not indicate the presence of adrenal insufficiency

THETHE ENDEND

surgical conditions thyroidectomy endocrine dysfunction - management thyroidectomy total...

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