Pediatric emergency medicine trisk 2007 2007
Bạn đang xem bản rút gọn của tài liệu. Xem và tải ngay bản đầy đủ của tài liệu tại đây (130.35 KB, 1 trang )
& Dohme) should be instituted as soon as a bite is confirmed in children who
weigh less than 40 kg; the usual dose is 2.5 mL (one vial). Antivenin should be
administered by following the package insert and after skin testing to determine
the risk of hypersensitivity to horse serum. For children who weigh more than 40
kg, it is not as urgent to institute antivenin treatment, but indications for its use
include patients who are younger than 16 years, who have respiratory difficulty,
or who have significant hypertension. Antivenin is usually effective within 30
minutes and may be repeated once within 2 hours if symptoms return. Serum
sickness is a possible side effect. Because the dosage is low, however, serum
sickness is uncommon, with a rate lower than reported for other types of
antivenin. A black widow spider bite in pregnancy is an indication for antivenin
due to the risk of venom-induced abortion, although the antivenin is a category C
drug. Other supportive measures include prolonged warm baths and intravenous
injection of 10% calcium gluconate as needed for muscle pain. If there is extreme
restlessness, barbiturates or benzodiazepines may be used, but with caution as the
venom is a neurotoxin and can cause respiratory paralysis. Muscle relaxants such
as diazepam have also been advocated, but they are variably effective and the
effects are short lived. Analgesia may be achieved with opiates.
Tarantulas and Others. Tarantulas do not bite unless provoked. The venom is
mild, and envenomation is not a problem. The wolf spider (Lycosa species) and
the jumping spider (Phidippus species) have also been implicated in bites. They
also have mild venom that causes only local reactions. Bites from all three of
these spiders should be treated with local wound care.
Tick Paralysis
Current evidence. Ticks are responsible for transmitting a variety of infectious
agents, including spirochetes, viruses, rickettsiae, bacteria, and protozoa.
Examples of tick-borne illness, which are discussed in Chapter 94 Infectious
Disease Emergencies , include Rocky Mountain spotted fever, Lyme disease,
tularemia, ehrlichiosis, babesiosis, relapsing fever, and Colorado tick fever. Tick
paralysis is associated with the bite of the wood tick, Dermacentor andersoni; the
dog tick, Dermacantor variabilis; and the deer tick, Ixodes scapularis. The gravid
engorged tick releases a neurotoxin that can produce cerebellar dysfunction or an
ascending paralysis. The mechanism of action of the toxin is not well understood.
Clinical assessment. Following tick attachment, there is a latent period of 4 to
7 days, followed by symptoms of restlessness, irritability, and ascending flaccid
paralysis. Respiratory paralysis and death may follow if the tick is not detected.
