ENDOCRINE DISEASES

1
ENDOCRINE DISEASES

• BY
• CYNTHIA L. DIETRICH, D.O.
• November 23, 2004

2
DIABETES MELLITUS

• Problem in glucose metabolism, accompanied by
  predictable long-term vascular and neurologic
  complications
• Chronic disease
• Significant morbidity and mortality

3
COMPLICATIONS

• Hyperglycemia /- ketoacidosis
• Hypoglycemia activation of the sympathetic
  nervous system (diaphoresis, tremulousness and
  tachycardia) and insufficient delivery of oxygen
  to the brain (confusion, seizures and
  unconsciousness

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• Retinopathy- microaneurysms cluster at
  macula-gtterminal vessels obstructed-gtischemia-gtnew
  vessel proliferation
• Nephropathy-leads to hypertension. Assoc with
  the highest mortality.
• Cardiovascular disease- silent ischemia
• Peripheral neuropathy- numbness and tingling
  progressing to total insensitivity
• Stiff joint syndrome- prayer sign and
  atlanto-occipital joint involvement

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• Autonomic nervous system dysfunction
• -orthostatic hypotension, resting tachycardia,
  absent beat-to-beat variation
• -hypogylcemic unawareness
• -gastroparesis occurs in 20-30

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IDDM

• Prevalence 0.4
• Onset most often prior to age 20
• Environmental influences are superimposed on a
  genetic component located on chromosome 6
• Absolute insulin deficiency
• Pancreatic beta islet cells are destroyed and
  anti-islet cell antibodies appear
• Clinical symptoms when 90 of the beta cells
  destroyed
• Associated with other autoimmune diseases
  rhuematoid arthritis and thyroid disease

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• Clinical presentation is unmistakable
  hypergylcemia, polyuria, polydipsia, weight loss,
  blurred vision and ketoacidosis
• Long term management requires exogenous insulin,
  self monitoring, lifestyle adaptations including
  diet and exercise
• Insulin formulations rapid (regular),
  intermediate (Lente, NPH) or long-acting
  (Ultralente)
• Goal- HbA1c less than 7.5

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DKA

• Insulin transfers glucose and amino acids into
  the cells.
• Hyperglycemia-gtosmotic diuresis-gtdehydration-gtacid
  osis. Also, a build up of amino acids in the
  blood-gtlipolysis-gtfree fatty acids-gtconverted to
  ketone bodies in the liver
• Results in a intravascular fluid volume deficit
  of 5-8 liters, potassium deficit of 200-400 mEq,
  and NaCl deficit of 350-600 mEq

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Treatment of DKA

• Intubate for CNS depression
• Regular insulin 10 units IVP followed by 5-10
  units/hr IV
• Normal saline 5-10 ml/kg/hr IV
• Add 5 glucose when serum blood sugarlt250 mg/dl
• Potassium 0.3-0.5 mEq/kg/hr IV
• Monitor blood sugar, potassium, arterial pH and
  urine ketones hourly
• Identify cause (sepsis, MI, compliance)

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ANESTHETIC MANAGEMENT

• Goal- blood sugar between 120-180 mg/dl
• Surgery scheduled early in the day
• ¼ to ½ usual daily dose of intermediate acting
  insulin on the morning of surgery
• Frequent blood sugar analysis, q 1-2 hours
  intraop
• Treat blood sugar values above 250 mg/dl

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• Tracheal intubation in patients with autonomic
  nervous system neuropathy (pre-treat with
  metoclopramide)
• Choice of drugs for induction and maintenance
  less important than monitoring of serum blood
  sugar
• /- regional anesthesia due to peripheral
  neuropathies
• Risk of peripheral nerve injury with positioning
• Bradycardia and hypotension may require epi

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NIDDM

• Obese, sedentary lifestyle, and advancing age
• Prevalence 6.6
• Insulin resistance and a decrease in insulin
  secretion
• Usual onset after age 40
• Insulin resistance is inherited
• Ketosis-resistant

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• Insulin-mediated stimulation of tyrosine kinase
  is impaired. This is necessary for normal
  function of insulin receptors.
• Effect is reversible with improved control of
  serum blood sugar
• When dietary management fails hypoglcemic drugs
  stimulate endogenenous insulin secretion, or
  inhibit gluconeogenesis in the liver and kidneys,
  and increase glucose uptake in skeletal muscles
• Duration can be up to 36 hours

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HYPEROSMOLAR, HYPERGLYCEMIC NONKETOTIC COMA

• -elderly, insulin deficiency, renal
  insufficiency, thirst deficiency
• -sepsis, hyperalimentation or drugs
  (corticosteriods)
• -glucose gt600 mg/dl
• -osmotic diuresis-gthypokalemia and dehydration
• -serum osmolarity gt350 mOsm/L
• -pH gt7.3
• -hypovolemia (severe, up to 25 total body water)
• -patients are insulin deficient but liver insulin
  levels sufficient for metabolism of free fatty
  acids-gtno ketosis
• -coma due to shrinkage of brain cells

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TREATMENT OF HHNC

• Regular insulin 10 units IVP then recheck
• Isotonic salt solution 2-3 liters over the first
  1-2 hours
• Subsequent half-strength saline
• When plasma glucose level approaches normal start
  D5W
• When urine output is resumed supplement potassium
• Remember this can be reversed with fluids
  alone, go slowly

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ANESTHETIC MANAGEMENT

• Same as IDDM except omit oral hypoglycemic the
  morning of surgery
• Keep in mind long duration of action of oral
  hypoglycemic drugs
• Obesity considerations

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GESTATIONAL DIABETES

• Glucose intolerance first detected during
  pregnancy
• 2-3 of all pregnancies
• Detected in the last trimester
• Resembles NIDDM (50 develop NIDDM within 10
  years)
• Risk factor for fetal morbidity
• Neonatal hypoglycemia
• Increased Respiratory Distress Syndrome,
  cardiomegaly and congenital abnormalities

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THYROID GLAND DYSFUNCTION

• Overproduction or underproduction of T3 and/or T4
• Negative feedback regulated by the anterior
  pituitary gland and the hypothalmus
• T3 and T4 act on cells through the adenylate
  cyclase system, producing changes in speed of
  biochemical reactions, total body oxygen
  consumption, and heat production

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HYPERTHYROIDISM

• Prevalence 2 women, 0.2 men
• Decreased TSH and increased T4
• Causes Graves Disease, iatrogenic, Toxic
  nodular goiter and Thyroiditis
• Signs and symptoms goiter, tachycardia,
  anxiety, tremor, heat intolerance, fatigue,
  weight loss, eye signs, skeletal muscle weakness
  and atrial fibrillation
• Stimulation of the sympathetic nervous system

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TREATMENT OF HYPERTHYROIDISM

• Antithyroid drugs (methimazole, carbimazole,
  propylthiouracil) inhibit oxidation/formation of
  iodothyromines before treatment with radioiodine
  or surgery
• B-adrenergic antagonists (propranolol, nadolol,
  atenolol) decrease some of the tachycardia,
  anxiety and tremor
• Inorganic iodine inhibits the release of T4 and
  T3 for a limited time to prepare pts for surgery
  or treat thyrotoxic crisis

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• Radioiodine therapy destroys thyroid tissue
• Subtotal thyroidectomy when radioiodine is
  refused or a large goiter is present causing
  tracheal compression or cosmetic concerns

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ANESTHETIC MANAGEMENT OF HYPERTHYROIDISM

• Elective surgery should be deferred until the
  patient is rendered euthyroid and hyperdynamic
  state controlled with B-blockers
• Preop anxiolytics and evaluation of upper
  airway (CT scan of the neck)
• Induction Thiopental has antithyroid activity
  (no ketamine)
• Maintenance isoflurane or sevoflurane (no
  halothane) and fentanyl or remi. Attention to
  body temp, heart rate and eye protection
  (exothalmos)
• Muscle relaxation avoid pancuronium and use
  glycopyrrolate with reversal agent
• Treat hypotension with phenylephrine

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COMPLICATIONS OF SUBTOTAL THYROIDECTOMY

• Damage to the recurrent laryngeal nerve when
  unilateral-gthoarseness, when bilateral-gttotal
  airway obstruction
• Damage to superior laryngeal nerve can lead to
  aspiration
• Airway obstruction from tracheomalacia (after
  extubation) or hematoma (early postop period)
• Hypoparathyroidism-gt hypocalcemia develops 24-72
  hours postop (but sometimes 1-3 hours
  postop)-gtlaryngeal stridor-gtlaryngospasm

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THYROTOXIC CRISIS (THYROID STORM)

• Medical emergency
• Typically presents 6-18 hours after surgery
• Abrupt onset of tachycardia, hyperthermia,
  agitation, skeletal muscle weakness, congestive
  heart failure, dehydration and shock due to
  abrupt release of T4 and T3 into the circulation
• Precipitated by surgery, infection, trauma,
  toxemia, DKA

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TREATMENT OF THYROID STORM

• Intraveneous cooled crystalloid solutions,
  acetominophen and cooling blankets
• Esmolol infusion with goal heart rate lt100
• Potassium iodide to block release of T4 and T3
• Propylthiouracil 100 mg po to inhibit conversion
  of T4 to T3
• Cortisol 100-200 mg IV

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HYPOTHYROIDISM

• Prevalence 0.5-0.8
• Increased TSH and decreased T4 and T3
• Cause is primarily treatment of hyperthyroidism,
  medically or surgically or Hashimotos
  Thyroiditis
• Signs and symptoms lethargy, hypotension,
  bradycardia, CHF, gastroparesis, hypothermia,
  hypoventilation, hyponatremia, and poor mentation
• Treatment with Synthroid

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ANESTHETIC MANAGEMENT OF HYPOTHYROISM

• Preop meds titrate and consider supplemental
  cortisol
• Induction ketamine
• Maintenance nitrous oxide plus short acting
  opioids, benzos or ketamine
• Low dose muscle relaxants
• Controlled ventilation of the lungs (vulnerable
  to excessive decrease in PaCO2)
• Treat hypotension with ephedrine
• Watch for CHF, consider arterial line and PA
  catheter

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ADRENAL GLAND DYSFUNCTION

• Hypercortisolism Cushings Syndrome
• Hypocortisolism Addisons Disease
• Pheochromocytoma

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CUSHINGS SYNDROME

• Caused by excessive secretion of corticotropin by
  anterior pituitary corticotroph tumors
  (microadenomas)
• Increased aldosterone, cortisol and testosterone
  in the adrenal cortex
• Signs and symptoms hypertension, hypokalemic
  alkalosis, hyperglycemia, hypernatremia,
  osteoporosis, easy bruising, polyuria, buffalo
  hump, moon facies, excessive body hair, menstrual
  abnormalities, weight gain, skeletal muscle
  wasting/weakness, depression and insomnia

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• Diagnosis with 24 hour urinary secretion of
  cortisol
• Dexamethasone suppression test distinguishes
  Cushings disease from the ectopic corticotropin
  syndrome
• Treatment of choice is transsphenoidal
  microadenomectomy or 85-90 resection of the
  anterior pituitary gland

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ANESTHETIC MANAGEMENT

• Preop evaluation of systemic blood pressure,
  electrolyte balance and the blood glucose
• No single anesthetic the best
• Replacement therapy hydrocortisone 10 mg/ hr for
  24 hours
• Treat hypertension and hypervolemia with a
  potassium sparing diuretic
• Treat hyperglycemia with insulin
• Care when positioning patient due to osteoporosis

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CORTISOL

• THE ONLY ESSENTIAL HORMONE FOR LIFE
• Maintains blood pressure by facilitating the
  conversion of norepi to epi
• Converts amino acids to glucose
• Suppresses inflammation

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ADDISONS DISEASE

• Absense of cortisol and aldosterone due to
  destruction of the adrenal cortex
• Causes hemorrhage in anticoagulated patients,
  sepsis, surgical or accidental trauma
• Diagnosis by measurement of plasma cortisol
  before and 1 hour after administration of
  corticotropin
• Signs and symptoms weight loss, skeletal muscle
  weakness, hypotension, fluid depletion,
  hyperkalemia, hyponatremia, hypoglycemia,
  abdominal/back pain

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MANAGEMENT OF A PATIENT WITH ADDISONS DISEASE

• You must give exogenous corticosteriods!
• Intraveneous infusion of sodium containing fluids
• Invasive monitoring with arterial line and CVP or
  PA catheter
• Frequent measurements of glucose and electrolytes
• Decrease initial dose of muscle relaxants

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PHEOCHROMOCYTOMA

• Catecholamine-secreting tumor that originates in
  the adrenal medulla or in the chromaffin tissues
  along the paravertebral sympathetic chain,
  extending from the pelvis to the base of the
  skull
• Age 30-50 years
• 50 deaths occur during unrelated surgery or
  pregnancy
• Diagnosis by 24 hour urine for norepinepherine
  and CT scan
• Associated with Multiple endocrine neoplasia (MEN)

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• Signs and symptoms tachycardia, diaphoresis,
  headache, hypertension, hyperglycemia,
  hypovolemia, tremulous, palpitations, weight loss
• Treatment is surgical excision of the tumor(s)

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ANESTHETIC MANAGEMENT OF PHEOCHROMOCYTOMA

• Correct hypovolemia (serial hematocrits)
• Alpha blockade before beta blockade
• Alpha blockage phenoxybenzamine 10-20 mg PO bid
  for 14 days pre-op
• Beta blockade propranolol 40 mg PO bid pre-op
• Pre-op benzo with scopalamine
• Avoid histamine releasing drugs
• Arterial line pre-induction

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• Induction etomidate, thiopental or propofol
• Lidocaine 1-2 mg/kg prior to intubation
• Consider PA catheter
• Maintenance sevoflurane due to rapid changes in
  concentration and fentanyl or remifentanyl
• Treat hypertension with phentolamine 1-5 mg IV or
  nitroprusside
• Treat reflex tachycardia with an esmolol infusion