adrenal disease Flashcards
diseases of the adrenal cortex
hyperadrenocorticism/cushings
hyperaldosteronism/conn’s
hypoadrenocorticism/addison’s
hypoaldosteronism
diseases of the adrenal medulla
pheochromocytoma
3 zones of the adrenal cortex
zona glomerulosa, zona fasciculata, zona reticularis
zona glomerulosa deals with which hormone
aldosterone (mineralcorticoid)
zona fasciculata deals with which hormone
cortisol (glucocorticoids)
zona reticularis deals with which hormone
androgens
what is the outer portion of the adrenal gland and what is the inner portion?
outer = cortex inner = medulla
the adrenal gland has one of the highest rates of
blood flow per gram of tissue
what makes up the HPA axis?
hypothalamus, anterior pituitary, and adrenal cortex
the adrenal medulla secretes
epi (80%) and norepi (20%)
cortisol physiological functions
blood glucose regulation, protein turnover, fat metabolism, sodium, potassium, and calcium balance, maintenance of CV tone, modulation of tissue response to injury/infection, survival from stress
what is the most important function of cortisol?
survival as a result from stress
Cushings syndrome vs cushings disease
syndrome - excess cortisol secretion or endogenous steroids
disease - inappropriate ACTH from pituitary
Cushing’s/hyperadrenocorticism can be ___
ACTH dependent or independent
ACTH dependent hyperadrenocorticism/Cushings caused from
pituitary corticotroph tumors, non-endocrine tumors in the lung, kidney, or pancreas (ectopic corticotropin syndrome)
ACTH independent hyperadrenocorticism/Cushings caused from
benign or malignant adrenocortical tumors
Cushings signs and symptoms
sudden weight gain, thickening of facial fat (moon face), electrolyte abnormalities, systemic HTN, glucose intolerance, menstrual irregularities, decreased libido, skeletal muscle wasting, depression and insomnia, and osteoporosis, hypercoaguable (risk of thrombosis)
diagnosis of cushings
24 urine collection, plasma cortisol levels = if both elevated = cushings CRH stimulation test dexamethasone suppression test inferior petrosal sinus sampling CT and MRI once diagnosis is confirmed
Dexamethasone suppression test
given high dose of dexamethasone if a pituitary tumor -maintains negative feedback system and can suppress ACTH
cushings treatment
based on cause
surgical - transphenoidal microadenectomy (if pituitary tumor), adrenalectomy (partial or total)
irradiation
electrolytes we would want to check preoperatively in a cushings patient
check for hypokalemia and hypernatremia
what acid base balance would you expect to see with cushings?
hypokalemic metabolic alkalosis
positioning considerations for cushings
may have osteoporosis/osteomalacia (risk for vertebral compression fractures), can be obese, careful with airway management, use appropriate padding
anesthetic considerations for muscle weakness in cushings
hypokalemia is usually the culprit, decreased requirements for muscle relaxants, use a PNS, maintain 1 twitch if possible (know that they are reversible), consider intubating (may have weak respiratory muscles)
considerations for a unilateral or bilateral adrenalectomy
100 mg glucocorticoid/24 hours, reduce dose over 3-6 days postop, may need to give mineralcorticoid supplementation
some inhalational agents depress adrenal response to
stress and ACTH
etomidate can lead to
adrenocortical suppression with long term infusion
it inhibits enzymes involved in cortisol and aldosterone synthesis
complications with transphenoidal microadenomectomy
VAE, transient diabetes insipidus (DI), meningitis
complications with laparoscopic adrenalectomy
risk for nerve injury in upper extremity d/t positioning
complications with open adrenalectomy
pulmonary complications from retraction which can lead to atelectasis
right adrenalectomy complication
could knick the liver or small intestine
left adrenalectomy complication
could knick the spleen, pancreas, or blood vessels to the kidneys
primary hyperaldosteronism (conn’s) definition
an excess secretion of aldosterone from a functional tumor
conn’s syndrome is more common in
women > men and rarely in children
secondary hyperaldosteronism
increased circulating serum renin stimulates the release of aldosterone (renovascular hypertension)
Conn’s disease signs and symptoms
non-specific and some can be asymptomatic systemic HTN (HA, diastolic 100-125mmHg), hypokalemia (skeletal muscle cramps and weakness, metabolic alkalosis)
systemic HTN in Conn’s disease is reflective of
aldosterone induced sodium and fluid retention and can be resistant to treatment!
anesthesia management for hyperaldosteronism
correct hypokalemia and HTN with spironolactone
assess cardiac/renal status
avoid hyperventilation!
adequate fluids with vasodilators/diuresis
exogenous cortisol 100mg/day
Addison’s Disease
primary adrenal insufficiency from an idiopathic/autoimmune cause or from bacterial/fungal/HIV infection
Someone with Addison’s disease typically don’t show symptoms until
90% of the adrenal cortex has been destroyed
Addison’s disease is a deficiency of
all adrenal cortex secretions = mineralocorticoids, glucocorticoids, and androgens
Someone with Addison’s disease is very susceptible to
death because their body cannot handle stress
Addison’s signs and symptoms
fatigue, muscle weakness, hypotension, weight loss, anorexia, NVD, increased BUN and hemoconcentration (hypovolemia, hyponatremia, hyperkalemia, hypoglycemia), abdominal/back pain, hyperpigmentation
diagnosis of Addison’s
cortisol level <20 ug/dL after ACTH stimulation test 30 and 60 minutes after administration of ACTH
normal response to ACTH stimulation test
plasma cortisol levels >25 ug/dL
Addisonian crisis is triggered in
steroid dependent patients who do not receive increased dose during stress that leads to circulatory collapse!
signs and symptoms of addisonian crisis
hypoglycemia, electrolyte imbalance, depressed mentation
treatment of addisonian crisis
IV cortisol 100 mg q4-6 h for 24 h, D5/0.9% NS, colloid and whole blood, inotropic support if needed
anesthetic management of addison’s
exogenous corticosteroids
25 mg for minor surgery
100mg bolus with infusion at 10mg/hr for major surgery
avoid etomidate?
patients are sensitive to inhalational agents myocardial depressive effects
titrate muscle relaxants and use PNS
intraoperative hypotension treatment in addison’s
rule out other causes, measure CVP - do they need fluid?
try vasopressor, cortisol 100mg, fluids, and may need invasive monitoring
hypoaldosteronism
congenital deficiency
or from hyporeninemia or nonsteroidal inhibitors of prostaglandin synthesis
hyporeninemia can cause hypoaldosteronism due to
long standing diabetes and renal failure and/or treatment with ACEi leading to a loss of angiotensin stimulation
nonsteroidal inhibitors of prostaglandin synthesis may inhibit
renin release and exacerbate condition in presence of renal insufficiency
signs and symptoms of hypoaldosteronism
hyperkalemic acidosis, hyponatremia, myocardial conduction defects
hypoaldosteronism treatment
mineralocorticoids - fludrocortisone
liberal sodium intake
pheochromocytoma is a
catecholamine secreting tumor
pheochromocytomas originate in
the adrenal medulla and related tissues elsewhere in the body (95% in abdominal cavity, 10% involve both adrenals)
pheochromocytomas are more common in
young to mid adult life adults (30s-50s)
predominant symptoms of pheochromocytoma
HTN continuous or paroxysmal, HA, diaphoresis/pallow, palpitations/tachycardia
associated symptoms with pheochromocytoma
orthostatic HoTN, anxiety, tremor, chest pain, epigastric pain, flushing, painless hematuria
is epi or NE secreted more in pheochromocytoma?
NE is released more than epi
diagnosis of pheochromocytoma
urine test - not for definitive diagnosis
plasma free metanephrines (normetanephrine >400, metanephrine >220)
CT/MRI
treatment of pheochromocytoma
surgical excision only definitive treatment
phenoxybenzamine or prazosin to produce alpha block
restore intravascular volume
restore release of insulin with alpha block
beta block
Why do we always alpha block before beta block?
if a nonselective beta block is administered in absence of alpha block heart depressed by beta block unable to maintain CO with unopposed alpha mediated vasoconstriction
pheochromocytoma patients may have hyperglycemia because
there is less circulating insulin with increased glycogenolysis
preop criteria for pheochromocytoma
no BP reading >165/90 for 48 hours prior to surgery
BP upon standing should not be <80/45
ECG without ST-T wave changes that aren’t already permanent
No more than 1 PVC every 5 minutes to avoid cardiac arrest
pheochromocytoma patients may have a falsely elevated
Hct so get a type and cross and prehydrate
what is an important goal for pheochromocytoma patients
fluid replacement/status
anesthetic considerations for pheochromocytoma
aline, heavy premedication, gentle positioning, epidural or combined anesthetic
induction considerations with pheochromocytoma
prepare for hyperdynamic BP
give lidocaine 1-2mg/kg
give sufentanil 0.5-1 mcg/kg or fentanyl 3-5 mcg/kg
give propofol 3mg/kg
what drugs would you avoid in pheochromocytoma
morphine and atracurium d/t histamine relase which stimulates catecholamine release pancuronium and atropine (increase HR) metoclopramide halothane succinylcholine
what is an alpha blocker of choice for pheochromocytoma
phentolamine
what is a beta blocker of choice for pheochromocytoma
esmolol
nitroprusside dose
1-2 mcg/kg
why is nitroprusside preffered in pheochromocytoma treatment
fast on and fast off
phentolamine considerations
tachyphylaxis, tachycardia, and longer duration
with surgical ligation of the pheochromocytoma what should we be prepared for?
hypotension! so stop antihypertensives, good communication with surgeon, decrease inhalational agent, try volume first, use phenylephrine and NE for pressors
why might you avoid succinylcholine in pheochromocytoma patients?
causes fasciculations of abdominal muscles which can cause release of catecholamines from the tumor
postop considerations for pheochromocytoma patients
50% stay hypertensive d/t elevated catecholamine levels for 10 days
may be hypoglycemic
need steroid supplementation if had bilateral adrenalectomies or hypoadrenalism
need adequate pain control
if postoperative HTN is lasting longer than 10 days what should you consider?
there is a presence of occult tumors or they are fluid overloaded
50% of undiagnosed pheochromocytomas die
under general anesthesia
