Part 1 of 2
Surf and turf, anyone?
And when I say “surf,” I am, of course, referring to our ocean-dwelling friends who “turf” water sport enthusiasts to the emergency department with their various bites and stings.
Before we “dive” (last nautical pun—we promise) into part one of our two-part series on marine envenomations, let’s review some general information and definitions.
General Management for All Marine Injuries
Yes, the vast majority of marine envenomations are completely benign in terms of long-term morbidity and mortality. Our goals in assessing these patients should be:
- To evaluate and monitor for potential life threats
- To decrease risk for future infection
- To reassure.
Pain is a big factor with marine envenomations. Surprisingly, some attempts to manage symptoms in benign cases may potentially worsen the envenomation or lead to unnecessary prescribing of strong pain medications. Reassurance that this is a self-limiting event and that there is no evidence of a life-threatening condition is of utmost importance.
Initial approach: All wounds should be irrigated (seawater or saline for saltwater species; freshwater for freshwater species) and explored for retained foreign bodies. Nematocysts, barbs, spines, and other foreign bodies can be removed manually (with gloves!) using forceps, adhesive tape, rubber cement, or facial peels. If the injury is deep or extensive or there is concern for a foreign body, obtain X-ray imaging. If X-rays are negative or if there is concern for radiolucent material, use ultrasound.
Treatment and management: For deep wounds, especially those involving joints or body cavities, early surgical consultation may be necessary. Infections from marine-associated injuries tend to be polymicrobial. Wounds should be swabbed (special media or cultures may be needed), and all patients should have tetanus vaccination updated. Be aware of the potential for necrotizing fasciitis (sometimes caused by Vibrio species), which is associated with serious saltwater injuries, especially in patients with pre-existing liver disease. Avoid suturing deep puncture wounds due to the high risk of infection. Pain should be managed with nonsteroidal anti-inflammatory drugs, acetaminophen, opioids, and/or topical analgesics (eg, lidocaine).
The following species-dependent topical measures may also be implemented:
- Hot water immersion (HWI): The injured area should be immersed in water that is 43-45°C (111–114°F) for 10–30 minutes (or until pain is controlled)
- Vinegar: 4–5 percent acetic acid solution should be applied to the injured area for at least 30 seconds. This treatment really only has evidence of benefit with the Australian box jellyfish. Studies with other species have actually shown it to encourage further nematocyte discharge.
- Stingose: A topical solution composed of 20 percent aluminum sulfate and 1.1 percent surfactant, Stingose is used for pain control, venom removal via osmosis, and venom neutralization via denaturation of proteins and polysaccharides through interactions with the aluminum ion.1
Note: There is very little danger in using fresh water, however, this may increase the patient’s pain due to increased nematocyst firing in certain species. It is always reasonable to attempt a small amount of vinegar initially and assess its effect.1
Antibiotic Treatment Recommendations2
No antibiotics are indicated if:
- Healthy patient
- Prompt wound care
- Wound is small or superficial and does not have associated foreign bod orbone or joint involvement
Prophylactic outpatient (oral) antibiotics if:
- Late wound care
- Large laceration or injuries
- Early or local inflammation
Hospital admission (IV antibiotics) if:
- Signs of systemic illness
- Deep wounds or significant trauma
- Retained foreign bodies
- Progressive inflammatory changes
- Penetration of bone, joint space, or body cavity
- Comorbid medical conditions
First generation cephalosporin or methicillin-resistant Staphylococcus aureus coverage (if concern) are appropriate for all patients requiring antibiotics and
- For seawater associated injuries (Vibrio coverage): fluoroquinolone or third generation cephalosporin
- For freshwater associated injuries (Aeromonas coverage): fluoroquinolone or trimethoprim-sulfamethoxazole or carbapenem
Although the literature discusses antivenom indications and dosing, the availability of such agents can be an issue. For example, the only location that has readily available marine antivenom is Australia (specifically, antivenom for stonefish and box jellyfish made by the Commonwealth Serum Laboratories).