260 Emergency Medicine
People are exposed to CO through fires, vehicle exhaust, home generators,
and the metabolism of methylene chloride. Workers also become sympto-
matic from use of propane-powered equipment indoors, such as forklifts
and ice skating resurfaces. Often, other people in the area have similar
complaints. The earliest symptoms are nonspecific and readily confused
with other illnesses such as viral syndromes. Mild symptoms include
headache, nausea, and dizziness. Severe symptoms include chest pain, pal-
pitations, and seizures. Diagnosis is made by detecting elevated CO in the
blood. Normal levels range from 0% to 5%, while smokers may be as high
as 10%. Treatment includes immediate oxygen therapy. Hyperbaric oxygen
is the treatment of choice for patients with significant CO exposures.
(a)Methemoglobinemia occurs from exposures to nitrates, certain
anesthetics, and various medications. Patients typically present cyanotic
with a normal PO 2 that does not respond to supplemental oxygen.
(b)Hypoglycemia can cause syncope. However, this patient’s blood glucose
was normal. (c)Hydrocarbon poisoning (eg, kerosene, gasoline, nail polish
remover) typically occurs from an intentional exposure. The pulmonary sys-
tem is most commonly affected. (d)Opioid overdose causes sedation and
respiratory depression.
236.The answer is d.(Rosen, pp 2133-2135.)Isopropyl alcoholis one of
thetoxic alcohols(ethylene glycol, methanol, and isopropyl alcohol). It is
a clear, colorless liquid with a bitter taste.It is commonly used as a rubbing
alcoholand as a solvent in haircare products, skin lotion, and home
aerosols. Moreover, it is often ingested as an inexpensive and convenient
substitute for ethanol. Clinically, GI and CNS complaints predominate. Its
GI irritant properties cause patients to complain of abdominal pain, nausea,
and vomiting. Pupillary size varies but miosis is commonly observed. Large
ingestions can result in coma. Hypotension, although rare, signifies severe
poisoning. Characteristically, metabolic acidosis, unlike the other toxic
alcohols, is not present. This is because isopropyl alcohol is metabolized to
acetone,a ketone, not an acid. It is also the cause for the presence of urinary
ketones and the odor on the patient’s breath. Isopropyl alcohol intoxication
is often remembered by ketosis without acidosis. Another unique finding
is the presence of “pseudo renal failure” or isolated false elevation of creati-
nine with a normal BUN. This results from interference of acetone and ace-
toacetate by the colorimetric method used to measure the creatinine level.
(a)If the patient had a history of diabetes with an elevated blood sugar
and ketones present in the urine, then DKA would be highly suspected.