it is termed irreducible or incarcerated. Incarcerated hernias are subject to
inflammatory and edematous changes and are at risk for strangulation,
which refers to vascular compromise of the incarcerated contents. When
strangulation is not emergently relieved, necrosis and gangrene develop.
The treatment for an incarcerated hernia that cannot be manually reduced
is surgical fixation. If strangulation is suspected or shock is present, broad-
spectrum antibiotics and fluid resuscitation are necessary.
(aandd)The physical examination is highly suspicious for the pres-
ence of intra-abdominal complications associated with the obstruction;
therefore a CT scan or plain film is unlikely to contribute further in the diag-
nosis.(b)If there is any question of the duration of the incarceration or
there is evidence of strangulation, no attempt at reduction should be made
so that dead bowel is not introduced into the abdominal cavity. (e)Antibi-
otics alone are insufficient, as surgery is also required.
112.The answer is b.(Rosen, pp 1301-1313.)Staphylococcal food poi-
soningis caused by an enterotoxin-forming strain of Staphylococcusorgan-
isms in the food before ingestion. Most protein-rich foodssupport the
growth of staphylococci, particularly ham, eggs, custard, mayonnaise, and
potato salad. The illness has an abrupt onset,beginning1 to 6 hoursafter
ingestion of the contaminated food. Cramping and abdominal pain, with
violent and frequent retching and vomitingare the predominant symp-
toms. Diarrhea is variable; it is usually mild, and occasionally absent.
Although often aggressive in onset, staphylococcal food poisoning is short-
livedand usually subsides in 6 to 8 hours,rarely lasting more than
24 hours.The patient is often recovering when first seen by a physician. The
short incubation periodandmultiple casesin people eating the same meal
are highly suggestive of this disease.
(a)Scombroid fish poisoning results from the ingestion of heat-stable
toxins produced by bacterial action on the dark meat of the fish (eg, tuna and
mackerel). The symptoms resemble histamine intoxication, occur abruptly
within 20 to 30 minutes and resemble histamine intoxication, consisting of
facial flushing, diarrhea, throbbing headache, palpitations, and abdominal
cramps. Antihistamine therapy is usually curative. (c)Clostridium perfringens
is probably the most common cause of acute food poisoning in the United
States. Most cases occur in fairly large outbreaks and are caused by the
ingestion of meat and poultry dishes. Symptoms usually appear within 6 to
12 hours but can occur up to 24 hours after ingestion of the contaminated
food. Frequent, watery diarrhea and moderately severe abdominal cramping
122 Emergency Medicine