Emergency Medicine Q & A, 2009, Pg

Emergency Medicine Q & A, 2009, Pg


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sting.
e. Treatment of signi\ufb01cant reactions to Hymenoptera stings may include epinephrine, antihistamines, and steroids
just like any anaphylactic reaction.
The answer is e. The acute local complications of a Hymenoptera sting include swelling and pain. Stings into the
eye globe can cause perforation, cataracts, and other long-term complications. A neuropathy can develop if the
stinger injects into a peripheral nerve. Killer bees are venomous but the venom has the same potency of other
Hymenoptera. Killer bees are \ufb01erce and attack in numbers, so death is secondary to the enormous load of toxin
delivered by a swarm of bees rather than the potency of the toxin. Systemic anaphylactic reactions can occur in
sensitized persons after one sting, but direct toxic reactions can develop in nonsensitized people after multiple stings
and include vomiting, syncope, and convulsions. Anaphylaxis is treated with epinephrine, antihistamines, and
steroids. In the patient with severe anaphylaxis 1 mL of 1:10,000 epinephrine may be given intravenously. The
1:1000 dilution is reserved for subcutaneous administration. A serum sickness-type illness may develop with fever,
arthralgias, and malaise 10 days to 2 weeks following stings.
... CHAPTER 6 Environmental Emergencies 85
4. Choose the true statement concerning treatment of snakebite:
a. Snakebites should be treated prophylactically with an antibiotic selected for its Gram-positive activity,
particularly against staphylococcal species.
b. The amount of antivenin given is based on the severity of the symptoms and laboratory data.
c. The dose of antivenin given to children is weight based.
d. Of the calculated dose of antivenin, 25\u201350% should be in\ufb01ltrated into the local wound of the bite and the rest
given intravenously.
e. Copperhead bites always require antivenin administration.
The answer is b. Snakebites generally do not get infected; therefore, prophylactic antibiotics are not warranted.
The amount of antivenin given is primarily a function of the severity of the envenomation. Children (or small
adults) should be given proportionately more antivenin because they receive a proportionately greater amount of
venom per kilogram of body weight than an adult. Antivenin is given intravenously and never injected into the area
of the local wound. The venom of the copperhead is mild and in general no antivenin is needed. However,
antivenin is indicated regardless of sensitivity if any symptoms occur after the bite of a coral snake.
5. You are evaluating a 70-kg woman who suffered 55% total body surface area second-degree burn in a kitchen
\ufb01re. She arrives within less than 20 minutes after the injury occurred. Using the Parkland formula, you
calculate the estimated total \ufb02uid requirements for the next 24 hours and the type and rate of \ufb02uid
administration (round to the nearest 10 mL) to be:
a. Ringer lactate, 960 mL/h in the \ufb01rst 8 hours, then 480 mL/h for the next 16 hours.
b. Ringer lactate, 640 mL/h for the next 24 hours.
c. Normal saline, 480 mL/h in the \ufb01rst 8 hours, then 960 mL/h for the next 16 hours.
d. Normal saline, 540 mL/h for the next 24 hours.
e. None of the above.
The answer is a. Several formulas for \ufb02uid replacement in burns are available. The Parkland formula calls for 4 mL
of lactated Ringer solution to be given per kilogram of body weight times the percentage burn. Half of this amount
is given in the \ufb01rst 8 hours and the rest given over the next 16 hours. Thus, 4 × 70 × 55 = 15,400 mL/24 h. In the
\ufb01rst 8 hours after the burn, 7700 mL is given at approximately 960 mL/h, and the remainder over the next 16
hours at approximately 480 mL/h. An important gauge of \ufb02uid replacement is the urine output, and the rate of
\ufb02uid administration should be modi\ufb01ed to maintain a urine output of 30\u201350 mL/h in adults, and 1 mL/kg/h in
children.
86 Emergency Medicine Q & A: Pearls of Wisdom ...
6. A 17-year-old man is pulled from the bottom of a neighbor\u2019s swimming pool where he was submerged for an
unknown period. Although initially pulseless and in respiratory arrest, his vital signs are now: heart rate
110/min; blood pressure 134/88 mmHg; respiratory rate 4/min. His Glasgow Coma Score is eyes, 1; verbal,
1 (intubated); motor, 2. His pupils are \ufb01xed and dilated. You know that:
a. Aspirated water signi\ufb01cantly interferes with successful ventilation from mechanical obstruction of airways.
b. Injuries of the cervical spine are uncommon.
c. A normal chest x-ray excludes signi\ufb01cant lung abnormalities.
d. Application of the Heimlich maneuver will help evacuate his lungs of excess \ufb02uid.
e. Twenty percent of near-drowning patients who are comatose and \ufb02accid with \ufb01xed and dilated pupils on arrival
in the ED fully recover.
The answer is e. The appearance of a patient after a near-drowning accident cannot reliably predict the outcome.
In particular, hypothermic near-drowning patients cannot be declared dead until their body temperature is at least
32.2\u25e6C (90\u25e6F). Not all patients require admission, but observation is indicated if there is any evidence of signi\ufb01cant
immersion or breathing abnormalities. Pulmonary complications may take several hours to evolve, and initial
normal chest x-rays do not exclude the development of pulmonary edema or hypoxia. These delayed complications
may account for past reports of a postimmersion syndrome and death following successful resuscitation. Cervical
spine injuries should be suspected in every near-drowning patient. Burst fractures of C1 and injuries of the
midcervical spine are common in diving accidents. Aspiration of large quantities of water is uncommon and no
special efforts should be made to \u201cpump out\u201d excess water. However, aspiration of water and water-borne
contaminants, with secondary loss of surfactant, in\ufb02ammation, and neurogenic pulmonary edema, contributes to
the respiratory insuf\ufb01ciency seen in near-drowning patients. Resuscitative efforts follow standard guidelines in
near-drowning patients, with consideration of possible hypothermia and occult cervical trauma or intoxication.
7. An 87-year-old woman is brought to the ED by \ufb01re rescue when her neighbors realized they had not seen her
for a few days. It is mid-August and the daily temperature has not gone below 87\u25e6F for more than a week.
The paramedics report that her apartment was \u201cunbearably hot\u201d and apparently cooled only by a small
revolving fan. The patient is comatose with a core temperature of 109.3\u25e6F and a blood pressure palpable at
60 mmHg. You institute therapy, knowing that:
a. Coagulation studies usually stay normal even after severe heatstroke.
b. Shivering that occurs during treatment must not be suppressed with chlorpromazine.
c. Sedation, paralysis and intubation reduce temperature by inhibiting muscular activity.
d. The presence of sweating excludes the diagnosis of heatstroke.
e. Heatstroke and heat exhaustion are differentiated by the height of fever.
The answer is c. Sweating can be present in early heatstroke, but later in the syndrome most patients develop hot,
dry skin and do not sweat. The most common reason for impaired sweating is use of drugs with anticholinergic
properties. Although exercise in hot weather is classically associated with its development, the disorder can occur,
especially in older patients, even at rest. The earliest clinical abnormality is a change in central neurologic function,
usually of the mental status; mental status changes are what differentiate heatstroke from the less severe heat
exhaustion. Focal neurologic \ufb01ndings suggesting a mass lesion may be seen. Tachycardia and fever are usually
present, but a sort of high-output cardiac failure can develop leading to pulmonary edema and cardiovascular
collapse. Purpura, thrombocytopenia, and clinically signi\ufb01cant bleeding can occur, sometimes progressing to DIC.
Patients with clinically signi\ufb01cant bleeding may require plasma and platelet replacement. The object