Poisoning and Overdose Answers 261(b)Differentiating between ethanol and isopropyl alcohol ingestion can be
very difficult. However, the patient’s clinical presentation of drinking a bit-
ter liquid, abdominal pain, nausea, vomiting, odor of acetone, and ketosis
without acidosis is most consistent with isopropyl alcohol intoxication.
(c and e)Methanol and ethylene glycol intoxication are typically associ-
ated with an anion gap metabolic acidosis.
237.The answer is a.(Rosen, pp 2076-2078.)The treatment of salicylate
toxicityhas three objectives: (1) prevent further salicylate absorption, (2)
correct fluid deficits and acid-base abnormalities, and (3) reduce tissue sal-
icylate concentrations by increasing excretion. Activated charcoalshould
be administered as soon as possible to reduce salicylate absorption. Dehy-
dration occurs early in salicylate intoxication and should be treated with IV
hydration. Urine alkalizationshould be considered in patients with sali-
cylate levels greater than 35 mg/dL. This is performed by administering IV
sodium bicarbonate. Because salicylic acid is a weak acid, it is ionized in an
alkaline environment and gets “trapped,” limiting the amount that crosses
the blood-brain barrier and increasing urinary excretion.
(b)Endotracheal intubation may be necessary in respiratory failure;
however, in a salicylate-poisoned patient, it is important to maintain hyper-
ventilation and an alkalotic environment in order to keep salicylic acid ionized
to limit it from crossing the blood-brain barrier. It is difficult to maintain an
appropriate level of hypocarbia and hyperventilation through assisted ventila-
tion.(c)NAC is the antidote for APAP poisoning. It is important, however, to
obtain an APAP level in patients with an aspirin overdose because the two may
occur together. (d)Hemodialysis for aspirin overdose should be considered in
patients with severe salicylism associated with serum salicylate levels greater
than 100 mg/dL; coma, renal, or liver failure; and pulmonary edema. Also with
severe acid-base disturbances or the failure to respond to more conservative
treatments such as activated charcoal and alkalization. (e)Observation with-
out intervention is not recommended with an aspirin overdose as there is a
risk of death.
238.The answer is b.(Rosen, pp 2069-2074.)IV NAC has been responsible
foranaphylactoid reactions, including rash, bronchospasm, hypoten-
sion, and death.These complications are dose and concentration dependent
and are prevented by slow administration of dilute NAC. Some other side
effects include GI disorders, tachycardia, and chest tightness.