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PANCE Review

Terms in this set (93)

What are the signs and symptoms of hyponatremia?
Weakness, nausea, anorexia, vomiting, confusion, lethargy, seizures, and coma
What are some causes of factitious hyponatremia?
Hyperglycemia, hyperliipidemia, and hyperproteinemia
How does hyperglycemia lead to hyponatremia?
Because glucose stays in the extracellular fluid, hyperglycemia draws water out of the cell into the extracellular fluid thus diluting the sodium. Each 100 mg/dL increase in plasma glucose decreases the serum sodium by 1.6 to 1.8 mEq/L
What is the most common cause of euvolemia hyponatremia in children?
Syndrome of inappropriate secretion of antidiuretic hormone (SIADH). Other causes include CNS disorders, medications, tumors, and pulmonary disorders
What is central pontine myelinolysis (osmotic demyelination syndrome)?
The complication of brain dehydration following the rapid correction of severe hyponatremia. Correct hyponatremia slowly, i.e., <12mEq/day for chronic hyponatremia
What are the signs and symptoms of hypernatremia?
Confusion, muscle irritability, seizures, respiratory paralysis, and coma
What are the most common causes of hypotonic fluid loss leading to hypernatremia?
Diarrhea, vomitting, hyperpyrexia, and excessive sweating
What are the ECG findings of a patient with hypokalemia?
Flattened T waves, depressed ST segments, prominent P and U waves, and prolonged QT and PR intervals
What are the ECG findings of a patient with hyperkalemia?
Peaked T waves, prolonged QT and PR intervals, diminished P waves, depressed T waves, QRS widening, and with levels near 10mEq/L, a classic sine wave
What are the causes of hyperkalemia?
Acidosis, tissue necrosis, hemolysis, blood transfusions, GI bleed, renal failure, Addison's disease, primary hypoaldosteronism, excess po K+ intake, RTA IV, and medication, such as succinylcholine, B-blockers, captopril, spironolactone, triamterene, amiloride, and high-dose PCN
What is the treatment for severe hyperkalemia?
Kayevalate, glucose, insulin, sodium bicarbonate, calcium gluconate or calcium chloride, dialysis, and high-dose nebulized albuterol
What are the causes of hypocalcemia?
Shock, sepsis, multiple blood transfusions, hypoparathyroidism, vitamin D deficiency, pancreatitis, hypomagnesemia, alkalosis, fat embolism syndrome, phosphate overload, chronic renal failure, loop diuretics, hypoalbuminemia, tumor lysis syndrome, and medication, such as Dilantin, phenobarbital, heparin, theophylline, cimetidine, and gentamicin
In order of prevalence, what are the three most common causes of hypercalcemia?
Malignancy, primary hyperparathyroidism, and thiazide diuretics
What are the signs and symptoms of hypercalcemia?
The most common GI symptoms are anorexia and constipation. Remember: Stones: Renal calculi, Bones: Osteolysis, Abdominal groans: PUD and pancreatitis, Psychic overtones: Psychiatric disorders
What is the initial treatment for hypercalcemia?
Restoration of the extracellular fluid with 5-10 L of NS within 24 hours. After the pt is rehydrated, administer furosemide in doses of 1-3 mg/kg. Pts with hypercalcemia are dehydrated because high calcium levels interfere with ADH and the ability of the kidney to concentrate urine
A pt with a history of alcohol abuse presents after a recent tonic-clonic seizure. What particular electrolyte abnormality should be considered and treated during evaluation?
Hypomagnesemia. Treat the pt with MgSO4, 2g IV over 1 hr. Total deficit is often 5-10 g.
What is the most common cause of secondary adrenal insufficiency and adrenal crisis?
Iatrogenic adrenal suppression from prolonged steroid use. Rapid withdrawal of steroids may lead to collapse and death
What are the most common causes of hyperphosphatemia?
Acute and chronic renal failure
What is thyrotoxicosis? What causes it?
A hypermetabolic state occurring secondary to excess circulating thyroid hormone. Thyrotoxicosis is caused by thyroid hormone overdose, thyroid hyperfunction, or thyroid inflammation
What are the hallmark clinical features of myxedema coma?
Hypothermia (75%) and coma
What is the most common cause of hypoglycemia seen in the ED?
An insulin reaction in a diabetic patient
What is the most important initial step in treating DKA?
Volume replacement, with the first liter administered over about 60 minutes
In the first two years of life, what is the most common cause of drug-induced hypoglycemia?
Salicylates. Between ages 2 and 8, alcohol is the most likely cause, and between ages 11 and 30, insulin and sulfonylureas are the primary causes
What principle hormone protects the human body from hypoglycemia?
Glucagon
What drugs potentiate the hypoglycemic effects of sulfonylurea?
Salicylates, alcohol, sulfonamides, phenylbutazone, and bis-hydroxycoumarin. Chlorpropamide is the sulfonylurea compound most likely to induce hypoglycemia events. It also causes the most prolonged hypoglycemia
How is sulfonylurea induced hypoglycemia treated?
IV glucose alone may be insufficient. It may require diazoxide, 300mg slow IV over 30 mins, repeated every 4 hours
Which is the most common type of hypoglycemia in children?
Ketotic hypoglycemia. This condition usually develops in boys between 18 months and 5 years of age. Attacks typically arise from caloric deprivation. These attacks may be episodic and are more frequent in the morning and during periods of illness
What are the neurologic signs and symptoms associated with hypoglycemia?
Hypoglycemia may produce mental and neurologic dysfunction. Neurologic manifestations can include paresthesias, cranial nerve palsies, transient hemiplegia, diplopia, decerebrate posturing, and clonus
What lab findings are expected with diabetic ketoacidosis?
Elevated B-hydroxybutyrate, acetoacetate, acetone, and glucose. Ketonuria and glucosuria are present. Serum bicarbonate levels, pCO2, and pH are decreased. Potassium levels may be elevated but will fall when the acidosis is corrected
Outline the basic treatment for DKA
Administer fluids.Start w/ NS (deficit may be 5-10L), followed by K, 100-200mEq in the first 12-24 hrs. Prescribe insulin 5-10 unit bolus followed by 5-10 units/hr. Add glucose to IV fluid when the glucose level falls below 250 mg/dL and give the pt a phosphate supplement when the levels drop below 1.0 mg/dL
What are the complications of bicarbonate therapy in DKA?
Paradoxical CSF acidosis, cardiac arrhythmias, decreased oxygen delivery to tissue, and fluid and sodium overload
A 42-year old female presents with a history of palpitations, sweating, diplopia, blurred vision, and weakness. Her husband states she has been confused, most notably before breakfast. What is a probable diagnosis?
Islet cell tumor of the pancreas which can result from fasting hypoglycemia
What are the key features of nonketotic hyperosmolar coma?
Hyperosmolality, hyperglycemia, and dehydration. Blood sugar levels should be >800mg/dL, serum osmolality should be >350mOsm/kg, and serum ketones should be negative
What is the treatment for nonketotic hyperosmolar coma?
Normal saline, potassium, 10-20mEq/hr, and insulin, 5-10 units/hr. Glucose should be added to the IV if the blood sugar level drops below 250mg/dL
What is the overall mortality rate of nonketotic hyperosmolar coma?
Approximately 50%
What is the most common precipitant of thyroid storm?
Pulmonary infections
What signs and symptoms are helpful for diagnosing thyroid storm?
Eye signs for Graves' disease, a history of hyperthyroidism, widened pulse pressure, HTN, a palpable goiter, tachycardia, fever, diaphoresis, increased CNS activity, emotional lability, heart failure, and coma
What pH decrease is expected with an increase of pCO2 of 10mmHg?
0.08
What pH increase in expected with a decrease of pCO2 of 10mmHg?
0.13
What pH increase in expected with a rise in HCO3 of 5.0mEq/L?
0.08
What pH decrease is expected with a decrease in HCO3 of 5.0mEq/L?
0.10
How is the anion gap calculated from electrolyte values?
Anion gap=Na-(Cl-HCO3) ; The normal gap is 12 +/- 4 mEq/L
Acidosis is closely related to anion gap measurement. Name the causes of increased anion gap acidosis:
A MUD PILE CAT: Alcohol, Methanol, Uremia, DKA, Paraldehyde, Iron & isoniazid, Lactic acidosis, Ethylene glycol, Carbon monoxide, Aspirin, Toluene
How can the magnitude of the anion gap be useful in narrowing the differential of an anion gap acidosis?
An anion gap >35mEq/L is usually caused by ethylene glycol, methanol, or lactic acidosis. An anion gap 23 to 30 mEq/L may be due to an increase in organic acids, and an anion gap 16-22 mEq/L may be result of advanced uremia
How is the osmolar gap determined?
Osmolality is a measure of the concentration of particles in a solution with units of osmoles per kg water. Osmolarity is a measure of osmoles per liter of solution. For dilute solutions, like body fluids, these two measures are roughly equivalent. An osmolar gap is the difference between the measured osmolality and the calculated osmolarity; normally 275-285mOsm/L
What clinical findings can narrow the differential of an anion gap acidosis?
Methanol: Visual disturbances and HA common-can produce wide gaps; Uremia: Must be advanced to contribute to wide gap; Diabetic ketoacidosis: Usually occurs with both hyperglycemia or glucosuria; Alcoholic ketoacidosis: Often has lower BS and mild or absent glucosuria; Salicylates: High levels required to contribute to gap
What causes an oxygen saturation curve to shift to the right?
A shift to the right delivers more O2 to the tissues. Remember: CADET! Right face! Hyper: Carbia, Acidemia; 2,3: DPG, Exercise; Increased Temperature, Release to tissues
When body waste materials, urine, and stool are internally recycled, they can cause a normal anion gap metabolic acidosis. Remember: USED CRAP
Ureteroenterostomy, Small bowel fistula, Extra chloride (NH4Cl or amino acid chlorides 2 to TPN), Diarrhea, Carbonic anhydrase inhibitors, Renal tubular acidosis, Adrenal insufficiency, Pancreatic fistula
Name the 2 primary causes of metabolic alkalosis:
Loss of hydrogen and chloride from the stomach and overzealous diuresis with loss of hydrogen, potassium, and chloride
Which types of nodules are more likely to be malignant on a thyroid scan, hot or cold?
Cold. This procedure should not be considered confirmatory. Cysts and benign adenomas can also read as cold. Some types of thyroid cancers will read as "warm" and thus be dismissed. Use caution when interpreting results.
What test should be performed to distinguish a benign cystic nodule from malignant nodule?
Fine needle aspiration biopsy and cytological aspiration
What is a solitary thyroid nodule most likely to be?
A nodular goiter (50%). Other possibilities to consider include cancer (20%), adenoma (20%), cyst (5%), or thyroiditis (5%)
What are the key predisposing factors to hypoglycemia in diabetic patients on insulin?
Exercise, poor oral intake, worsening renal function, and medications are key predisposing factors to consider
What is the major mechanism of hyponatremia in DKA patients?
Dilution of sodium due to shifting of water out of the cells into the vascular space.
What major insults are likely to lead to DKA in an otherwise controlled diabetic?
Always look for infection (even a minor one), cardiac ischemia, medications, lack of compliance with insulin and diet
What medications are likely to worsen glucose control in a diabetic patient?
This list is long, but includes thiazide diuretics, B-blockers, steroids, estrogens, dilantin, cyclosporin, diazoxide
What are the key factors leading to hypernatremia in a patient with non-ketogenic hyperosmolar coma?
Profound dehydration with greater losses of water than salt as well as impaired thirst
What are some complications of hypophosphatemia seen in treated DKA?
Rhabdomyolysis, cardiac dysfunction, arrhythmias, hemolysis, poor neutrophil function
What are the key factors predisposing diabetics to soft-tissue infection?
Microvascular disease, poor wound healing and trauma are often masked by neuropathy
What are some agents used to treat severe diabetic gastroparesis?
Cisapride and metoclopramide are the key agents. Erythromycin has also been tried in severe cases
Diffuse abdominal pain with bloody stools and a high serum lactate in a diabetic might suggest what gastrointestinal disease?
You should strongly consider ischemic or necrotic bowel
What medications are likely to lead to acute hyperkalemia in a diabetic patient?
NSAIDs, ACE-Is, B-blockers, potassium sparing diuretics and salt substitutes
What are common causes of abdominal pain, nausea and vomiting in a diabetic patient?
Diabetic gastroparesis, gallbladder disease, pancreatitis, and perhaps, bowel ischemia
Atypical chest pain in an elderly diabetic individual should always suggest what sundrome?
Cardiac ischemia. Diabetic patients have a high risk of cardiac ischemia and this must always be strongly considered even if the pain is somewhat atypical
What is the most desirable agent used to treat severe hyperglycemia in pregnancy?
These patients must have tight glycemic control achieved by multiple injections of insulin
What do profound polyuria and dehydration in DKA reflect?
Severe osmotic diuresis caused by glycosuria
What is the possible adverse effect seen during very rapid correction of severe hyperglycemia?
Cerebral edema
What are the major adverse effects of IV radiocontrast dye given to diabetic patients?
Acute tubular necrosis is well known. One should also watch for worsening of CHF, precipitation of angina pectoris and hemodynamic compromise
What characteristic lab findings are associated with primary adrenal insufficiency?
Hyperkalemia, hyponatremia, hypoglycemia, azotemia (if volume depletion is present), and a mild metabolic acidosis
What are the main causes of death during an adrenal crisis?
Circulatory collapse and hyperkalemia induced arrhythmias
What are the causes of acute adrenal crisis?
Major stress, such as surgery, severe injury, MI, or any other acute illness in a pt with primary or secondary adrenal insufficiency
Secretion of which adrenal hormone is not impaired by secondary adrenal insufficiency?
Aldosterone. Aldosterone secretion is more dependent upon angiotensin II than corticotropin, and aldosterone deficiency is not a problem in hypopituitarism. Selective aldosterone hypersecretion can manifest as a result of increased renin and angiotensin II formation.
What are the causes of acute abrupt primary adrenal insufficiency?
Adrenal hemorrhage, necrosis, thrombosis in meningococcal disease, sepsis, anticoagulation therapy or the antiphospholipid syndrome
What are the causes of abrupt secondary adrenal insufficiency?
Sheehan's syndrome (postpartum pituitary necrosis), bleeding into a pituitary macroadenoma, and head trauma
What diseases produce slow insidious progression to produce adrenal insufficiency?
Autoimmune diseases, TB, systemic fungal infections, AIDS, metastatic carcinoma, and lymphoma
What are common clinical manifestations of adrenal insufficiency?
Fatigue, lethargy, anorexia, wt loss, hyperpigmentation, hyponatremia, and hyperkalemia are common. Depression, dizziness, orthostatic hypotension, N/V/D, lymphocytosis, eosinophils and normocytic, normochromic anemia are also significant manifestations
Are orthostatic hypotension and electrolyte abnormalities more common in primary or secondary adrenal insufficiency?
Primary, because of the aldosterone deficiency and hypovolemia
What are the most specific signs of primary adrenal insufficiency?
Hyperpigmentation of the skin and mucosal membranes due to high ACTH levels as a consequence of cortisol feedback and salt craving
Does a normal cortisol in a critically ill pt rule out adrenal insufficiency?
No. With critical illness, one should expect a cortisol level greater than normal and a normal level could be considered relatively insufficient. An absolute level of 25 ug/dL probably rules out adrenal insufficiency, although the lower cutoff is unknown
How is a corticotropin (ACTH) stimulation test performed to rule out adrenal insufficiency?
After a baseline cortisol level is obtained (time 0), 250ug of Cosyntropin is given IV (or IM), and cortisol levels are obtained at 30 and 60 minutes post injection. Adrenal function is thought to be normal if the cortisol level drawn at the time 30 minutes or 60 minutes is >/= 20ug/dL
What are the three tests used to evaluate secondary adrenal insufficiency?
Insulin induced hypoglycemia, short-term Metyrapone tests, and the corticotropin releasing hormone test
After an endocrinologic diagnosis has been established by hormonal studies, the radiologic study of choice to assess for pituitary or hypothalamic tumor would be?
MRI with analysis of the sagittal and coronal sections. A CT scan can be helpful if bony invasion is suspected
Are imaging studies of the adrenal glands necessary in primary adrenal insufficiency?
Yes. In cases other than autoimmune or adrenal myeloneuropathy, a CT scan of the adrenal should be performed to aid in the differential diagnosis. Enlarged glands with/without calcifications in pts with TB are a sign of active disease and warrant anti-infective therapy. Enlargement also occurs in other fungal infections, lymphoma, cancer and AIDS. A biopsy by CT guidance may also be helpful
What is the emergent steroid replacement in adrenal insufficiency?
Hydrocortisone 50-100mg IV every 8 hrs initially
What is the daily replacement of hydrocortisone for adrenal insufficiency once the patient is stabilized?
Hydrocortisone 15mg in the am and 10mg in the pm. The dose should be the smallest possible to alleviate clinical symptoms yet prevent wt gain and osteoporosis. Measurements of urinary cortisol may help determine the appropriate dosage
What added precautions should be taken by all patients with adrenal insufficiency?
They should wear a medical alert bracelet, carry a card detailing their medications and recommendations for treatment in emergencies, and to double or triple their dose of hydrocortisone when they sustain injury or illness. They should secure ampules of glucocorticoids for self-injection or suppositories when vomiting or unable to take oral steroids
What accounts for the almost immediate effect of cortisol on blood pressure in pts with adrenal insufficiency?
Cortisol exerts a permissive effect on catecholamine vascular responsitivity and a vital role in the maintenance of vascular tone, vascular permeability and distribution of body water within the vascular compartment
What is the characteristic hemodynamic pattern of adrenal insufficiency?
Predominantly, decreased systemic vascular resistance to a lesser degree, decreased cardiac contractility depending upon the volume status
What is the amount of increased cortisol production that accompanies surgery?
It depends upon the surgery; 85% above baseline for up to two days post laparotomy and 35% above baseline for more minor procedures involving joints, breasts or neck
Which drugs can increase the metabolism of cortisol?
Phenytoin, phenobarbitol, and Rifampin
Is there any evidence to support the use of corticosteroids in septic shock?
No beneficial effects of corticosteroids have been shown in sepsis of septic shock. In fact, they may be harmful, according to several studies
Randomized prospective trials have shown benefit from corticosteroids in which disease states?
Bacterial meningitis, acute spinal injury, typhoid fever, Pneumocystis carinii PNA, and possibly tx of the fibroproliferative phase of aute respiratory distress syndrome
What symptoms should increase the suspicion of adrenal insufficiency in the critically ill?
Unexplained circulatory instability, high fever without cause, unresponsive to ABX, hypoglycemia, hyponatremia, hyperkalemia, neutropenia, eosinophilia, unexplaned mental status changes, disparate anticipated severity of disease and the actual state of the pt
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