CME questions: dysnatremias: why are patients still dying?1. A 31-year-old female with no past medical history undergoes elective laparoscopic cholecystectomy. Postsurgically, intravenous 5% dextrose dextrose: see glucose. 1/4 normal saline is started and maintained at 125 cc per hour. The patient remains too sedated to go home and she is admitted to the hospital. Intravenous meperidine meperidine (me-per´i-den) an opioid analgesic, used as the hydrochloride salt as an analgesic and an anesthesia adjunct. meperidine a centrally acting analgesic with spasmolytic properties equal to those of atropine. is given, with adequate relief of her pain. Because she is not tolerating oral intake, the IV fluids are continued at the current rate. The following morning, the patient is complaining of severe headache and nausea. Two hours later the patient has a generalized seizure. Lab values are listed: Sodium (mEq/L) 122 Potassium (mEq/L) 3.9 Chloride (mEq/L) 96 Bicarbonate (mEq/L) 22 BUN (mg/dL) 16 Creatinine (mg/dL) 1.1 Serum osmolality (mOsm/kg) 268 Glucose (mg/dL) 104 What is the most important step in preventing the complication of post-operative hyponatremic encephalopathy? a. Encourage early enteral fluid intake following surgery b. Use 0.9% NaCl intravenous fluids in the post-operative period, unless a free water deficit is present c. Use pain medications judiciously 2. Which of the following is a recognized risk group for a poor outcome among patients with hyponatremic encephalopathy? a. Children b. Hypoxic hypoxic a state of hypoxia. hypoxic cell sensitizers compounds that selectively sensitize hypoxic tumor cells to the effects of radiation. patients c. Premenopausal pre·me·no·paus·al adj. Of or relating to the years or the stage of life immediately before the onset of menopause. premenopausal adjective females d. All of the above 3. Which class of diuretics Diuretics Definition Diuretics are medicines that help reduce the amount of water in the body. Purpose Diuretics are used to treat the buildup of excess fluid in the body that occurs with some medical conditions such as congestive heart is most likely to lead to hyponatremia Hyponatremia Definition The normal concentration of sodium in the blood plasma is 136-145 mM. Hyponatremia occurs when sodium falls below 130 mM. Plasma sodium levels of 125 mM or less are dangerous and can result in seizures and coma. ? a. Carbonic anhydrase inhibitors Carbonic anhydrase inhibitors are a class of pharmaceuticals that suppress the activity of carbonic anhydrase. Types Acetazolamide is an inhibitor of carbonic anhydrase. It is used for glaucoma, epilepsy (rarely), benign intracranial hypertension, and altitude sickness. b. Vasopressin receptor (V2) blockers c. Potassium-sparing diuretics d. Loop diuretics e. Thiazide diuretics 4. Which of the following is nearly always necessary for the development of hypernatremia Hypernatremia Definition The normal concentration of sodium in the blood plasma is 136-145 mM. Hypernatremia is defined as a serum sodium level over 145 mM. Severe hypernatremia, with serum sodium above 152 mM, can result in seizures and death. ? a. Impaired urinary concentrating ability b. Salt wasting nephropathy nephropathy /ne·phrop·a·thy/ (ne-frop´ah-the) disease of the kidneys.nephropath´ic analgesic nephropathy c. Impaired access to water d. Renal insufficiency 5. A 74-year-old man who weighs 65 kg had been prescribed DDAVP[R] for urinary incontinence. He takes 10 mcg intranasally twice a day. He presents to the emergency room with seizures and diminished mental status. The electrolytes in the blood and urine are given below: Serum Sodium (mEq/L) 107 Potassium (mEq/L) 3.5 Chloride (mEq/L) 74 Bicarbonate (mEq/L) 23 BUN (mg/dL) 11 Creatinine (mg/dL) 0.6 Glucose (mg/dL) 97 Phosphorus (mg/dL) 3.2 Albumin (g/dL) 3.6 Osmolality (mOsm/kg) 234 Urine Sodium (mEq/L) 105 Potassium (mEq/L) 46 Osmolality (mOsm/kg) 540 He is placed in an intensive care unit, all fluid intake restricted (NPO NPO [L.] nil per os (nothing by mouth). NPO abbr. Latin nil per os (nothing by mouth) NPO Nothing by mouth ) and treated with 3% normal saline at 60 cc per hour. DDAVP[R] is held at this time. Eight hours later, the patient has had no recurrent seizure activity, his mental status is improved, urine output is now 200 cc per hour and the following laboratories are obtained: Serum Sodium (mEq/L) 121 Potassium (mEq/L) 3.5 Chloride (mEq/L) 87 Bicarbonate (mEq/L) 23 BUN (mg/dL) 11 Creatinine (mg/dL) 0.6 Glucose (mg/dL) 97 Phosphorus (mg/dL) 3.2 Albumin (g/dL) 3.6 Osmolality (mOsm/kg) 26 Urine Sodium (mEq/L) 32 Potassium (mEq/L) 21 Osmolality (mOsm/kg) 134 He is undergoing a water diuresis diuresis /di·ure·sis/ (di?u-re´sis) increased excretion of urine. osmotic diuresis that resulting from the presence of nonabsorbable or poorly absorbable, osmotically active substances in the at this point. To prevent continued ongoing water losses and overcorrection o·ver·cor·rec·tion n. An adjustment that surpasses a set criterion, especially of a desired behavior. of the serum sodium, what is the best course of action in the management of this patient? a. Discontinue 3% saline, start 0.9% saline b. Discontinue 3% saline, administer DDAVP[R], keep patient NPO c. Continue 3% saline, administer DDAVP[R], keep patient NPO d. Encourage oral fluid intake 6. Which of the following are risk factors for cerebral demyelination demyelination /de·my·elin·a·tion/ (de-mi?e-li-na´shun) destruction, removal, or loss of the myelin sheath of a nerve or nerves. Called also myelinolysis. (CPM) during the correction of hyponatremia? a. Liver disease b. Increase in serum sodium of > 25 mEq/L in 48 hours c. Hypoxic/ anoxic an·ox·i·a n. 1. Absence of oxygen. 2. A pathological deficiency of oxygen, especially hypoxia. [an- + ox(o)- + -ia1. episode d. Increase in serum sodium to normonatremia or hypernatremia e. All of the above 7. Using the urine output, the ratio of the sodium + potassium in the urine ([[Na.sup.+]][.sub.u] + [[K.sup.+]][.sub.u]) to the ratio of the sodium + potassium in the plasma ([[Na+].sub.pl] + [[K+].sub.pl]) which of the following statements is true concerning water losses in the urine in the patient below? Sodium (mEq/L) 152 Potassium (mEq/L) 3.1 Chloride (mEq/L) 115 Bicarbonate (mmol/L) 24 Urea nitrogen (mg/dL) 46 Creatinine (mg/dL) 1.2 Urine output (cc per hour) 225 Urine sodium (mEq/L) 25 Urine potassium (mEq/L) 21 Urine osmolality (mOsm/kg) 115 a. Urinary water losses are high and therefore this patient likely has diabetes insipidus b. The urinary water losses appear normal in this patient c. There is no water loss in the urine 8. A 23-year-old female has collapsed 45 minutes after completing a marathon. Her friends are present and they state that this is her first time competing in a marathon and she had been feeling well before the race. Her past medical history and past surgical history are negative. She completed the race in 4 and one-half hours. She is disoriented dis·o·ri·ent tr.v. dis·o·ri·ent·ed, dis·o·ri·ent·ing, dis·o·ri·ents To cause (a person, for example) to experience disorientation. Adj. 1. and severely short of breath on arrival to the emergency room. Physical exam is significant for a normal cardiac exam, crackles in all lung fields and a non-focal neurological exam. Chest x-ray shows pulmonary edema. Serum sodium is 123 mEq/L. Which of the following are risk factors for exercise induced hyponatremia? a. Slow runners b. Post-race increase in weight c. Female gender d. All of the above 9. An 83-year-old man, resident of a nursing home, is brought in via EMS because he is poorly responsive. He is visited weekly by his son and he noticed him to be very lethargic and "not himself today." One month ago he was hospitalized for aspiration pneumonia and he was discharged to the nursing home two weeks ago. He failed swallowing study evaluations in the hospital and has been discharged with a gastrostomy tube. His medical history is significant only for Alzheimer's dementia and hypertension. Medications are atenolol atenolol /aten·o·lol/ (ah-ten´ah-lol) a cardioselective ß used in the treatment of hypertension and chronic angina pectoris and the prophylaxis and treatment of myocardial infarction and cardiac arrhythmias. and aspirin. Physical exam: BP 78/45, P 118, T 96.7, R 12. The patient is lethargic, poorly arouseable and unable to speak. His mucous membranes are dry. Chest exam is clear and cardiovascular exam reveals no murmurs or gallops. He has no peripheral edema. Serum Sodium (mEq/L) 188 Potassium (mEq/L) 4.1 Chloride (mEq/L) 133 Bicarbonate (mEq/L) 31 BUN (mg/dL) 19 Creatinine (mg/dL) 2.3 Glucose (mg/dL) 119 What is the best first step in managing the dysnatremia in this patient? a. Infusion of intravenous 5% dextrose b. Boluses of tap water via PEG tube c. Intravenous infusion of normal saline (0.9% saline) d. Intravenous infusion of 1/2 normal saline (0.45% saline) 10. A 6-day-old infant is brought in for evaluation of mild fever. The delivery was uncomplicated and the child left the hospital 24 hours after birth. His mother states that he has been doing well but she does note that he is usually hungry soon after she feeds him. She is breast feeding exclusively. Vital signs are normal. What abnormality should make the physician suspicious for breast feeding-associated hypernatremia? a. Abnormal liver transaminases b. Hyperbilirubinemia c. Systolic hypertension d. Myoclonus myoclonus /my·oc·lo·nus/ (mi-ok´lo-nus) shocklike contractions of a muscle or a group of muscles.myoclon´ic essential myoclonus e. Distended distended Medtalk Enlarged, bloated. Cf Nondistended. abdomen Answers to CME CME See: Chicago Mercantile Exchange CME See Chicago Mercantile Exchange (CME). Questions 1. B, 2. D, 3. E, 4. C, 5. B, 6. E, 7. A, 8. D, 9. C, 10. B |
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