Altered Mental Status Answers 289typically not appearing until after a week has passed. (c)In viral meningitis,
the cerebrospinal fluid (CSF) WBC count is made up of lymphocytes or
monocytes, but early in the disease, polys may predominate. CSF glucose is
normal and protein is elevated in viral meningitis. A Gram stain will be neg-
ative and culture will show no growth. (d)Fungal meningitis is rare and
generally presents in immunocompromised patients. LP usually reveals
< 500/μL WBCs. (e)Encephalitis is diagnosed by CSF culture or serology.
CSF analysis that reveals blood is suspicious for herpes encephalitis.
264.The answer is c.(Tintinalli, pp 169-171.)Hyponatremiais defined as
a measured serum sodium less than 135 mEq/L. However, the development
of symptoms secondary to hyponatremia is related more to the rate of change
in the serum sodium than to the absolute value. Levels less than 120 mEq/L
tend to cause symptoms regardless of the rate to reach this value. Symptoms
can include confusion, lethargy, nausea, vomiting, anorexia, muscle cramps,
and seizures. There are many causes of hyponatremia, including renal or GI
losses, third-spacing, endocrine abnormalities, syndrome of inappropriate
antidiuretic hormone release (SIADH), cirrhosis, CHF, and nephrotic syn-
drome. Many medications cause SIADH, in addition to pulmonary and CNS
disease. This patient, in particular, just started chemotherapy for lung cancer.
The treatment for hyponatremia is guided by the cause of the process. How-
ever, if a patient is symptomatic (eg, seizing), hypertonic saline (3%)should
be carefully administered to raise the serum sodium to 120 mEq/L. A known
complication of hypertonic saline when it is administered too fast and sodium
levels rise rapidly is the development of central pontine myelinosis.
(a and b)0.45% and 0.9% do not provide adequate amounts of
sodium to raise the serum level and can actually cause a drop in serum
sodium in certain conditions. (d and e)Dextrose is the treatment of choice
for hypoglycemic patients.
265.The answer is c.(Tintinalli, p 1046.)Neuroleptic malignant syn-
drome (NMS)is a rare, but potentially fatal reaction commonly associated
with the use of antipsychotic drugs. The classic triad for its clinical presen-
tation includes altered mental status, hyperthermia, and muscle rigidity.
The cornerstone of treatment is supportive care with rapid cooling, fluid and
electrolyte repletion, and monitoring. Dantrolene, a nonspecific skeletal
muscle relaxant, generally used in the treatment of malignant hyperther-
mia, is also effective for NMS. In addition, benzodiazepines are useful in
the treatment of NMS. The offending agent should be discontinued.