of a cubomedusan envenomation, such as that of Carukia barnesii. Excessive catecholamine stimulation is
one putative cause, which has prompted clinical intervention with phentolamine, an -adrenergic blocking
agent (5 mg intravenously as an initial dose, followed by an infusion of up to 10 mg/hr). Bronchospasm may
be managed as an allergic component. If the victim is in respiratory distress with wheezing, shortness of
breath, or heart failure, arterial blood gas measurement may be used to guide supplemental oxygen
administration by face mask. Seizures are generally self-limited but should be treated with intravenous
diazepam for 24 to 48 hours, after which time they rarely recur.
Any victim with a systemic component should be observed for a period of at least 6 to 8 hours because
rebound phenomena after successful treatment are not uncommon. All elderly victims should undergo
electrocardiography and be observed on a cardiac monitor, with frequent checks for arrhythmias. Urinalysis
demonstrates the presence or absence of hemoglobinuria, indicating hemolysis after the putative attachment of
Physalia venom to red blood cell membrane glycoprotein sites. If this is the case, the urine should be
alkalinized with bicarbonate to prevent the precipitation of pigment in the renal tubules, while a moderate
diuresis (30 to 50 ml/hr) is maintained with a loop diuretic (such as furosemide or bumetanide) or mannitol
(0.25 g/kg intravenously every 8 to 12 hours). In rare instances of acute progressive renal failure, peritoneal
dialysis or hemodialysis may be necessary.
If there are signs of distal ischemia or an impending compartment syndrome, standard diagnostic and
therapeutic measures apply. These include Doppler ultrasound, angiography, or both for diagnosis, regional
thrombolysis for acutely occluded blood vessels, measurement of intracompartmental tissue pressures to guide
fasciotomy, and so forth. Reversible regional sympathetic blockade may be efficacious if vasospasm is a
dominant clinical feature. However, the vasospasm associated with a jellyfish envenomation may be severe,
prolonged, and refractory to regional sympathectomy and intraarterial reserpine or pentoxifylline.
A small child may pick up tentacle fragments on the beach and place them into his or her mouth,
resulting in rapid intraoral swelling and potential airway obstruction, particularly in the presence of
exceptional hypersensitivity. In such cases an endotracheal tube should be placed before edema precludes
visualization of the vocal cords. In no case should any liquid be placed in the mouth if the airway is not
protected.
Chironex fleckeri, the box-jellyfish, produces the only coelenterate venom for which a specific
antidote exists. To date, the venoms of Physalia and Chrysaora species have not been sufficiently purified as
antigens to permit the production of an antitoxin. Antivenom administration may be lifesaving and should
accompany the first aid protocol previously described.
Pain Control. Often the pain can be controlled by treating the dermatitis. However, if pain is
excruciating and there is no contraindication (such as head injury, altered mental status, respiratory
depression, allergy, profound hypotension), the administration of a narcotic (morphine sulfate, 2 to 10 mg
intravenously; nalbuphine, 2 to 10 mg intravenously or intramuscularly; meperidine, 50 to 100 mg, with
hydroxyzine, 25 to 50 mg intramuscularly, or meperidine, 15 to 30 mg, with promethazine, 12.5 to 25 mg, or
prochlorperazine, 2.5 mg intravenously) is often indicated. Severe muscle spasm may respond to 10% calcium
gluconate (5 to 10 ml intravenous slow push), diazepam (5 to 10 mg intravenously), or methocarbamol (1 g,
no faster than 100 mg/min through a widely patent intravenous line).
Treatment of Dermatitis. If a person is stung by a coelenterate, the following steps should be taken:
1. Immediately rinse the wound with seawater, not with fresh water. Do not rub the wound with a
towel or clothing to remove adherent tentacles. Nonforceful fresh water rinsing or a rubbing variety of
abrasion (the latter in the absence of simultaneous application of a decontaminant such as papain or vinegar)
is felt to stimulate any nematocysts that have not already fired. Surf life savers (lifeguards) in the United
States and Hawaii have reported that a fresh water hot shower applied with a forceful stream may decrease the
pain of an envenomation. If this is successful, one theoretical explanation is that the mechanical effect of the
water stream (that dislodges tentacle fragments and/or stinging cells) supercedes the deleterious (sting-
stimulating) effect of the hypotonic water. Remove any gross tentacles with forceps or a well-gloved hand. In
an emergency, the keratinized palm of the hand is relatively protected, but take care not to become
envenomed.
Commercial (chemical) cold or ice packs applied over a thin dry cloth or plastic membrane have been
shown to be effective when applied to mild or moderate Physalia utriculus ("bluebottle" - see below) stings.
