MARINE ATTACKS and ENVENOMATIONS
Paul S. Auerbach, M.D.
Abridged from Wilderness Medicine, 4
th
edition, St. Louis, Mosby, 2001
The expanses of ocean and fresh water that cover the earth are the greatest wilderness. Seventy-one percent of
the earth's surface is composed of ocean, the volume of which exceeds 325 million cubic miles. Within the
undersea realm exists four fifths of all living organisms.
The opportunity for direct encounters with aquatic organisms is constantly increasing because of
recreational, industrial, scientific, and military oceanic and riverine activities. The underwater recovery of
historical artifacts and treasures will accelerate in the new millenium. As fishermen harvest their catches, they
handle animals that bite and sting in self-defense.
Although noxious marine organisms are concentrated predominantly in warm temperate and tropical seas,
particularly in the Indo-Pacific region, hazardous animals may be found as far north as 50
o
latitude. Increasing
numbers of saltwater aquaria in private homes and public settings, intercontinental seafood shipping, and
accessibility of air travel for sport divers create additional risks.
Despite the wondrous nature of the deep, jeopardy exists. The ubiquity of hazardous creatures and
their propensity to appear at inopportune times make it imperative to be aware of them, to respect their
territorial rights, and to avoid needless unpleasant contact with them.
General Principles of First Aid
The physician must adhere to fundamental principles of medical rescue. While many injuries and
envenomations have unique clinical presentations, the cornerstone of therapy is immediate attention to the
airway, respiration, and circulation. Along with specific interventions directed against a particular venom or
poison, the rescuer must simultaneously be certain that the victim maintains a patent airway, breathes
spontaneously or with assistance, and is supported by an adequate blood pressure. Because marine attacks and
envenomations may affect a scuba diver, the rescuer should anticipate near drowning, immersion
hypothermia, and decompression sickness or arterial air embolism. Any victim rescued from the ocean should
be thoroughly examined for external signs of a bite, puncture, or sting.
Wound Management
Whether the injury is a bite, abrasion, or puncture, meticulous attention to basic wound management is
necessary to minimize posttraumatic infection.
WOUND IRRIGATION
All wounds acquired in the natural aquatic environment should be vigorously irrigated with sterile
diluent, preferably a normal saline (0.9% sodium chloride) solution. Seawater is not a favorable irrigant
because it carries a hypothetical infection risk. Sterile water or hypotonic saline is acceptable. Tap water
(preferably disinfected) appears to be a suitable irrigant and should be used when the alternative is delay to
irrigation. Irrigation should be performed before and after debridement to maximize the benefits. A 19-gauge
needle or 18-gauge plastic intravenous catheter attached to a syringe that delivers a pressure of 10 to 20 PSI
will dislodge most bacteria without forcing irrigation fluid into tissue along the wound edges or deeper along
dissecting tissue planes. Convenient ring-handle syringes with blunt irrigation tips and intravenous (IV)
tubing that connects to standard IV bags are available. At least 100 to 250 ml of irrigant should be flushed
through each wound. If a laceration is from a stingray, proteinaceous (and possibly) heat-labile venom may be
present in the wound. In such a case the irrigant should be warmed to 113
o
F (45
o
C).
An antiseptic may be added to the irrigant if the wound appears to be highly contaminated. Povidone-
iodine solution in a concentration of 1% to 5% may be used with a contact time of 1 to 5 minutes. When
antiseptic irrigation is completed, the wound should be thoroughly irrigated with normal saline or tap water to
minimize tissue toxicity. Antiseptics that are particularly harmful to tissues include full-strength hydrogen
peroxide, povidone-iodine scrub solution, hexachlorophene detergent, and silver nitrate.
Scrubbing should be employed to remove debris that cannot be irrigated from the wound. Sharp
surgical debridement is preferable to sponge scrubbing, which may increase infection rates, particularly when
applied with harsh antiseptic solutions.
WOUND DEBRIDEMENT
