Daniel Orr The Highs and Lows Thyroid Problems in the ICU.
-
Upload
alexa-cochran -
Category
Documents
-
view
215 -
download
0
Transcript of Daniel Orr The Highs and Lows Thyroid Problems in the ICU.
![Page 1: Daniel Orr The Highs and Lows Thyroid Problems in the ICU.](https://reader033.fdocuments.in/reader033/viewer/2022061305/55143aa25503466d1a8b54c0/html5/thumbnails/1.jpg)
Daniel Orr
The Highs and Lows
Thyroid Problems in the ICU
![Page 2: Daniel Orr The Highs and Lows Thyroid Problems in the ICU.](https://reader033.fdocuments.in/reader033/viewer/2022061305/55143aa25503466d1a8b54c0/html5/thumbnails/2.jpg)
Thyroid - Hypothyroidism
– Definition– Defect within the hypothalamic-pituitary-thyroid axis, with the
net result of inadequate thyroid hormone production
• Majority are primary - affecting thyroid gland itself– Causes include
» Hashimoto’s thyroiditis» Thyroidectomy» Radioiodine & Deficiency/excess» Drugs» Intentional - carbimazole/propylthiouracil» Side effect - lithium, amiodarone
![Page 3: Daniel Orr The Highs and Lows Thyroid Problems in the ICU.](https://reader033.fdocuments.in/reader033/viewer/2022061305/55143aa25503466d1a8b54c0/html5/thumbnails/3.jpg)
Thyroid - Myxoedema Coma
– Definition• Misnomer
• Severe Hypothyroidism with– Altered mental state
– Hypothermia
– Other organ failure
– Typically triggered by underlying illness or event
![Page 4: Daniel Orr The Highs and Lows Thyroid Problems in the ICU.](https://reader033.fdocuments.in/reader033/viewer/2022061305/55143aa25503466d1a8b54c0/html5/thumbnails/4.jpg)
Thyroid - Myxoedema Coma
– Incidence• Rare
– F>M (80%)– Elderly, > 60 years– 90% cases during winter months– Mortality ~ 30%
![Page 5: Daniel Orr The Highs and Lows Thyroid Problems in the ICU.](https://reader033.fdocuments.in/reader033/viewer/2022061305/55143aa25503466d1a8b54c0/html5/thumbnails/5.jpg)
Thyroid - Myxoedema Coma
– Clinical Findings• Preexisting hypothyroid symptoms (collateral from
relatives)– General
» Fatigue, weight gain, cold intolerance, constipation
» Anaemia
– Specific
» Myxoedema, skin, hair, face, tongue, hoarseness
» Eye signs
![Page 6: Daniel Orr The Highs and Lows Thyroid Problems in the ICU.](https://reader033.fdocuments.in/reader033/viewer/2022061305/55143aa25503466d1a8b54c0/html5/thumbnails/6.jpg)
Thyroid - Myxoedema Coma
– Clinical Findings - All organ systems affected• CNS
– Altered state of consciousness typical
» Lethargy, obtunded
» Seizures possible
• Thermoregulation– Depression of hypothalamic function
– Patients typically cool, temperatures 24oC reported!
– Normothermia/hypothermia may represent sepsis
![Page 7: Daniel Orr The Highs and Lows Thyroid Problems in the ICU.](https://reader033.fdocuments.in/reader033/viewer/2022061305/55143aa25503466d1a8b54c0/html5/thumbnails/7.jpg)
Thyroid - Myxoedema Coma
• CVS– Overall reduction in metabolic requirements, therefore
reduction in cardiac output
– Bradycardia, decreased myocardial contractility
– Reduced pulse pressure with diastolic hypertension, or hypotension
– Cardiac failure rarely seen owing to reduced cardiac demands
![Page 8: Daniel Orr The Highs and Lows Thyroid Problems in the ICU.](https://reader033.fdocuments.in/reader033/viewer/2022061305/55143aa25503466d1a8b54c0/html5/thumbnails/8.jpg)
Thyroid - Myxoedema Coma
• Resp– Hypoventilation typical
– Results in respiratory acidosis and hypoxaemia
– Owing to
» central depression of respiratory drive, and responsiveness to O2 and CO2
» Pump failure
» Sleep apnoea
![Page 9: Daniel Orr The Highs and Lows Thyroid Problems in the ICU.](https://reader033.fdocuments.in/reader033/viewer/2022061305/55143aa25503466d1a8b54c0/html5/thumbnails/9.jpg)
Thyroid - Myxoedema Coma
• Metabolic & Renal– Hyponatraemia
» Secondary to decreased renal perfusion (increased creatinine) and impaired free water clearance (SIADH)
» May be significant enough to contribute to alteration in mental state
» Other electrolyte disturbance may occur by similar mechanisms
– Hypoglycaemia
» Occurs concomitantly with hypothyroidism, even in the absence of adrenal insufficiency or hypo-pituitary disease
![Page 10: Daniel Orr The Highs and Lows Thyroid Problems in the ICU.](https://reader033.fdocuments.in/reader033/viewer/2022061305/55143aa25503466d1a8b54c0/html5/thumbnails/10.jpg)
Thyroid - Myxoedema Coma
• Pathogenesis– Overall decrease in oxygen and substrate usage by all
organ systems– CVS
• Myocardium– Alteration in gene expression– Both systolic and diastolic function depressed
» Failure of contraction, compliance and filling– Rhythm disturbance
» PVCs» Torsade
![Page 11: Daniel Orr The Highs and Lows Thyroid Problems in the ICU.](https://reader033.fdocuments.in/reader033/viewer/2022061305/55143aa25503466d1a8b54c0/html5/thumbnails/11.jpg)
Thyroid - Myxoedema Coma
• Pathogenesis– CVS
• Vasculature– Decreased release of nitric oxide, promoting increased
vascular resistance
• Perfusion– Overall reduction, but tissue oxygenation reduced also, so
A-V O2 difference preserved
![Page 12: Daniel Orr The Highs and Lows Thyroid Problems in the ICU.](https://reader033.fdocuments.in/reader033/viewer/2022061305/55143aa25503466d1a8b54c0/html5/thumbnails/12.jpg)
Thyroid - Myxoedema Coma
• Pathogenesis– Trigger
• Intercurrent illness– LRTI, UTI
– AMI, GIH, CVA
– Should be investigated for and excluded
![Page 13: Daniel Orr The Highs and Lows Thyroid Problems in the ICU.](https://reader033.fdocuments.in/reader033/viewer/2022061305/55143aa25503466d1a8b54c0/html5/thumbnails/13.jpg)
Thyroid - Myxoedema Coma
• Diagnosis• Based initially on history, examination and exclusion of other
forms of coma
• High TSH and low T4 useful in confirming diagnosis, but clouded somewhat in secondary hypothyroidism (Low TSH and T4)
• Other findings include– Anaemia (normochromic, normocytic)
– Normal WCC
– Raised CK (skeletal muscle source)
![Page 14: Daniel Orr The Highs and Lows Thyroid Problems in the ICU.](https://reader033.fdocuments.in/reader033/viewer/2022061305/55143aa25503466d1a8b54c0/html5/thumbnails/14.jpg)
Thyroid - Myxoedema Coma
• Management– Specific
• Replacement of thyroxine mainstay of treatment
• Exact means of replacement controversial– Bolus dose of T3/T4 to commence followed by
‘intermediate’ dosing
– Both high and low doses associated with increased mortality
![Page 15: Daniel Orr The Highs and Lows Thyroid Problems in the ICU.](https://reader033.fdocuments.in/reader033/viewer/2022061305/55143aa25503466d1a8b54c0/html5/thumbnails/15.jpg)
Thyroid - Myxoedema Coma
• Management– Considerations
– Availability of intravenous preparations (owing to ileus)
– T3 v T4 v Combination
– Precipitation of AMI, arrhythmia
• Corticosteroids– Use of corticosteroids recommended until coexisting
adrenal insufficiency is excluded
![Page 16: Daniel Orr The Highs and Lows Thyroid Problems in the ICU.](https://reader033.fdocuments.in/reader033/viewer/2022061305/55143aa25503466d1a8b54c0/html5/thumbnails/16.jpg)
Thyroid - Myxoedema Coma
• Management– Supportive
• Intubation & Ventilation– Often required for decreased conscious state and
correction of respiratory acidosis and hypoxia
– Ongoing hypoxia may persist secondary to intrapulmonary shunting
• Vascular tone– Vasopressors often required in early stages
![Page 17: Daniel Orr The Highs and Lows Thyroid Problems in the ICU.](https://reader033.fdocuments.in/reader033/viewer/2022061305/55143aa25503466d1a8b54c0/html5/thumbnails/17.jpg)
Thyroid - Myxoedema Coma
• Management– Supportive
• Fluid management– Balance– Volume resuscitation required, but risk of precipitating cardiac
failure– Appropriate fluids considered to allow for slow correction of
Sodium (fluid restriction often advocated), consideration of HTS
• Thermoregulation– Passive warming only, as active warming will precipitate shock
as a result of vasodilitation
![Page 18: Daniel Orr The Highs and Lows Thyroid Problems in the ICU.](https://reader033.fdocuments.in/reader033/viewer/2022061305/55143aa25503466d1a8b54c0/html5/thumbnails/18.jpg)
Thyroid - Myxoedema Coma
• Management– Supportive
• Empiric broad spectrum antibiotics– Take cultures first
![Page 19: Daniel Orr The Highs and Lows Thyroid Problems in the ICU.](https://reader033.fdocuments.in/reader033/viewer/2022061305/55143aa25503466d1a8b54c0/html5/thumbnails/19.jpg)
Thyroid - Myxoedema Coma
• Complications• Hypoglycaemia
– iv glucose may be required
• Arrhythmia– Cardiac monitoring required
• Ileus/Megacolon• LRTI• Hyponatraemia• Intubation
– May be difficult as a consequence of myxomatous change
![Page 20: Daniel Orr The Highs and Lows Thyroid Problems in the ICU.](https://reader033.fdocuments.in/reader033/viewer/2022061305/55143aa25503466d1a8b54c0/html5/thumbnails/20.jpg)
Thyroid - Myxoedema Coma
• Considerations• Drug clearance
• Other endocrine disorders
![Page 21: Daniel Orr The Highs and Lows Thyroid Problems in the ICU.](https://reader033.fdocuments.in/reader033/viewer/2022061305/55143aa25503466d1a8b54c0/html5/thumbnails/21.jpg)
Thyroid - Hyperthyroidism
• Definition• Excessive levels of circulating thyroid hormone
• Results in generalised acceleration of metabolic processes
• Aetiology– Graves
– Toxic Adenoma/MNG
– Iodine induced
– TSH mediated
– Germ cell tumours
– Surgical
– Cause has implications for treatment
![Page 22: Daniel Orr The Highs and Lows Thyroid Problems in the ICU.](https://reader033.fdocuments.in/reader033/viewer/2022061305/55143aa25503466d1a8b54c0/html5/thumbnails/22.jpg)
Thyroid - Hyperthyroidism
• Incidence/Prevalence/Prognosis– F>M 5:1– Prevalence 1.3%
• Clinical Features– CNS
– Anxiety, emotional lability– Weakness– Tremor
![Page 23: Daniel Orr The Highs and Lows Thyroid Problems in the ICU.](https://reader033.fdocuments.in/reader033/viewer/2022061305/55143aa25503466d1a8b54c0/html5/thumbnails/23.jpg)
Thyroid - Hyperthyroidism
• Clinical Features– Eyes/Skin
– Lid Lag
– Exophthalmos
– Sweating
– CVS– Tachycardia, palpitations and AF
– Increased cardiac output, increased contractility
– Widening pulse pressure, decreased SVR
– Heart failure
– SOB
![Page 24: Daniel Orr The Highs and Lows Thyroid Problems in the ICU.](https://reader033.fdocuments.in/reader033/viewer/2022061305/55143aa25503466d1a8b54c0/html5/thumbnails/24.jpg)
Thyroid - Hyperthyroidism
• Clinical Features– Resp
– Dyspnoea
– Increased O2 consumption and CO2 production
– Potential hypoxaemia and hypercapnia
– GIT– Increased motility with diarrhoea and malabsorption
![Page 25: Daniel Orr The Highs and Lows Thyroid Problems in the ICU.](https://reader033.fdocuments.in/reader033/viewer/2022061305/55143aa25503466d1a8b54c0/html5/thumbnails/25.jpg)
Thyroid - Hyperthyroidism
• Pathogenesis– T3 binds nuclear receptors upregulating genes responsible for
calcium cycling in the cardiac myocyte
• Myocardium– Increased heart rate, contractility, cardiac output, and myocardial
oxygen consumption, AF a precipitant for heart failure
• Vasculature– Reduction in SVR and diastolic pressure– Pulmonary hypertension
![Page 26: Daniel Orr The Highs and Lows Thyroid Problems in the ICU.](https://reader033.fdocuments.in/reader033/viewer/2022061305/55143aa25503466d1a8b54c0/html5/thumbnails/26.jpg)
Thyroid - Storm
– Life threatening thyrotoxicosis, often with a precipitant history
– Mortality > 10%
– Burch and Wartofsky scoring system designed to clarify the diagnosis
![Page 27: Daniel Orr The Highs and Lows Thyroid Problems in the ICU.](https://reader033.fdocuments.in/reader033/viewer/2022061305/55143aa25503466d1a8b54c0/html5/thumbnails/27.jpg)
Thyroid - Storm
– CVS• Tachycardia, rate related
• Shock worst case scenario
• Heart failure, oedema, bibasal creps, pulmonary oedema
– Thermoregulation• >40 degrees common
– CNS• Agitation, delirium, or degree obtundation considered
essential to diagnosis
![Page 28: Daniel Orr The Highs and Lows Thyroid Problems in the ICU.](https://reader033.fdocuments.in/reader033/viewer/2022061305/55143aa25503466d1a8b54c0/html5/thumbnails/28.jpg)
Thyroid - Storm
– GIT• NVD, hepatic failure with jaundice
– Pathogenesis• Typically a trigger
– Acute infection/Stress response - AMI/Trauma– Both Thyroidal and non-thryoidal surgery– Radioiodine treatment
• Occurs on a background (usually) of those with know hyperthyroidism
![Page 29: Daniel Orr The Highs and Lows Thyroid Problems in the ICU.](https://reader033.fdocuments.in/reader033/viewer/2022061305/55143aa25503466d1a8b54c0/html5/thumbnails/29.jpg)
Thyroid - Storm
– Genesis thought to be related to• Decreased levels of thyroid binding globulin in
above conditions, rather than raised total level of thyroid hormones, resulting in increased unbound fraction of T3 & 4
• Increased number of adrenergic binding sites, resulting in increased sensitivity to catecholamines
![Page 30: Daniel Orr The Highs and Lows Thyroid Problems in the ICU.](https://reader033.fdocuments.in/reader033/viewer/2022061305/55143aa25503466d1a8b54c0/html5/thumbnails/30.jpg)
Thyroid - Storm
• Diagnosis– Raised T4 (& 3) and TSH depending upon
disorder
– Radioiodine uptake scan to differentiate
![Page 31: Daniel Orr The Highs and Lows Thyroid Problems in the ICU.](https://reader033.fdocuments.in/reader033/viewer/2022061305/55143aa25503466d1a8b54c0/html5/thumbnails/31.jpg)
Thyroid - Storm
• Management• Management of Thyroid storm is the same as for
uncomplicated hyperthyroidism, but the patient should be managed in an intensive care environment
– Specific• Beta Blockade
– Multiple forms– Consideration of verapamil, if contraindicated
• Thionamide therapy– Propylthiouracil, dual effect
![Page 32: Daniel Orr The Highs and Lows Thyroid Problems in the ICU.](https://reader033.fdocuments.in/reader033/viewer/2022061305/55143aa25503466d1a8b54c0/html5/thumbnails/32.jpg)
Thyroid - Storm
• Iodine solutions– Sodium ipodate
– Potassium iodide
– Lugol’s solution
• Corticosteroids
• Plasmapheresis/PD may be effective in removing excess thyroid hormone
![Page 33: Daniel Orr The Highs and Lows Thyroid Problems in the ICU.](https://reader033.fdocuments.in/reader033/viewer/2022061305/55143aa25503466d1a8b54c0/html5/thumbnails/33.jpg)
Thyroid - Storm
– Supportive• Active cooling, paracetamol
– Avoid aspirin due to PPB
• Antiarrhythmics
• Volume resuscitation/Diuresis
• Antibiotics
• Sedation/Intubation/Ventilation
![Page 34: Daniel Orr The Highs and Lows Thyroid Problems in the ICU.](https://reader033.fdocuments.in/reader033/viewer/2022061305/55143aa25503466d1a8b54c0/html5/thumbnails/34.jpg)
Thyroid - Storm
• Complications– Airway complications as a result of goitre
• Considerations– Anticoagulation for AF