Medication Summary
The goal of therapy is to control pain and prevent infections in high-risk wounds. Medical therapy is directed at providing local and systemic analgesia, wound care, and supportive therapy, including antivenom when necessary. With the exception of persons with deep puncture wounds and those who are immunocompromised, prophylactic antibiotics generally are not indicated. Once infection is established, however, prompt therapy must be instituted with emphasis on coverage for potential marine pathogens. Tetanus prophylaxis is indicated in all marine animal injuries.
A review of opioid equivalents and conversions may be found in the article Opioid Equivalents and Conversions.
Antivenom
This agent has clearly established efficacy for analgesia and diminution of tissue damage following envenomation by Synanceia species and may be considered for serious or nonresponding stings of other members of the Scorpaenidae family. It generally is not indicated for Pterois envenomations. [3]
Unlike box jellyfish (Chironex) envenomations, which often require immediate antivenom administration, the clinical situation after stonefish envenomation may allow for a skin test for sensitivity to horse serum to be performed. The purpose of skin testing is to allow for adequate preparation of pretreatment, if needed, not to decide whether to administer the antivenom. This decision is based upon the clinical condition of the patient before skin testing. In addition to pretreatment, a positive skin test may warrant greater antivenom dilution in order to be safely administered.
All Australian marine antivenoms were previously made by and available from the Commonwealth Serum Laboratories, 45 Poplar Road, Parkville, Vic 3052, Australia. However, Australian venom research is now centered at the Australian Venom Research Unit, Department of Pharmacology, University of Melbourne, Parkville, Vic 3052, Australia (tel: 61-3-934447753; fax: 61-3-93482048). Stonefish antivenom is no longer available at the Health Services Department, Sea World, San Diego, CA; Sharp Cabrillo Hospital, San Diego, CA; Steinhart Aquarium, San Francisco, CA; or at Sea World, Aurora, OH. Regional poison control centers may be the most helpful sources of information. Known severe sensitivity to horse serum may prompt consideration of supportive therapy without antivenom administration.
This agent is currently not available in the United States.
Local anesthetics
Class Summary
These agents provide local or regional anesthesia as an adjunctive or alternative pain control.
Bupivacaine (Marcaine, Sensorcaine)
In general, any of the commonly used local anesthetics suffices; however, bupivacaine provides superior duration of anesthesia for irrigation, wound exploration, and debridement as compared to shorter-acting anesthetics. Bupivacaine increases the patient's electrical excitation threshold, which slows nerve impulse propagation and reduces the action potential; therefore, it prevents the generation and conduction of nerve impulses.
Analgesics
Class Summary
Analgesics are used for adjunctive pain control when immersion therapy and local/regional anesthesia are not sufficient.
Morphine sulfate (MS Contin, Astramorph, Avinza, Depodur, Duramorph, Infumorph, Kadian, MorphaBond, Arymo ER)
Morphine sulfate is the drug of choice for narcotic analgesia owing to its reliable and predictable effects, safety profiles, and ease of reversibility with naloxone. Morphine sulfate administered intravenously may be dosed in a number of ways and is commonly titrated until the desired effect is obtained. The analgesic route, whether oral or parenteral, is a matter of choice. With appropriate local or regional anesthesia, this medication may not be necessary.
For chronic severe pain unremitting to alternative therapy, oral immediate–release and extended-release morphine sulfate may be warranted. Arymo ER is a morphine sulfate abuse-deterrent derivative.
Antibiotics
Class Summary
Antibiotics are used for outpatient treatment of early or minor wound infections and as prophylaxis for high-risk wounds (eg, deep puncture wounds, grossly contaminated wounds, persons who are chronically ill or immunocompromised). Trimethoprim/sulfamethoxazole, ciprofloxacin, tetracycline, and doxycycline are referenced as the initial oral antibiotics of choice. Others mentioned include cephalexin, amoxicillin, and amoxicillin clavulanate.
Parenteral antibiotics are indicated for serious wound infections (eg, extensive cellulitis, myositis, gas gangrene) or sepsis following injuries sustained in the marine environment. Vibrio wound infection approaches 50% mortality (usually patients with chronic liver disease), and serious Aeromonas infection may mimic clostridial gas gangrene.
Trimethoprim/sulfamethoxazole (Bactrim, Septra)
Trimethoprim/sulfamethoxazole inhibits bacterial synthesis of dihydrofolic acid by competing with para-aminobenzoic, acid-inhibiting, folic acid synthesis. This results in the inhibition of bacterial growth. The antibacterial activity of TMP-SMZ includes the common urinary tract pathogens except Pseudomonas aeruginosa.
Ciprofloxacin (Cipro)
Ciprofloxacin is a bactericidal antibiotic that inhibits bacterial DNA synthesis and, consequently, growth by inhibiting DNA-gyrase in susceptible organisms. It is indicated for pseudomonal infections and those that are due to multidrug resistant gram-negative organisms. The duration of treatment depends on the severity of infection. Generally, treatment should be continued for at least 2 days after the signs and symptoms of infection have disappeared. The usual treatment duration is 7-14 days. No controlled studies exist regarding efficacy of therapy. Several references suggest both a tetracycline and either an extended-spectrum cephalosporin (eg, ceftazidime) or an aminoglycoside.
Tetracycline (Sumycin)
Tetracycline treats susceptible bacterial infections of both gram-positive and gram-negative organisms as well as infections caused by Mycoplasma, Chlamydia, and Rickettsia species. It inhibits bacterial protein synthesis by binding with the 30S, and possibly the 50S, ribosomal subunit(s) of susceptible bacteria.
Doxycycline (Doryx, Bio-Tab)
Doxycycline inhibits protein synthesis and, thus, bacterial growth by binding with the 30S, and possibly the 50S, ribosomal subunits of susceptible bacteria
Ceftazidime (Fortaz, Ceptaz)
Ceftazidime is a third-generation cephalosporin that has a broad gram-negative spectrum, lower efficacy against gram-positive organisms, and higher efficacy against resistant organisms. By binding to one or more of the penicillin-binding proteins, it arrests bacterial cell wall synthesis and inhibits bacterial growth.
Ampicillin (Marcillin, Omnipen)
Ampicillin interferes with bacterial cell wall synthesis during active multiplication, causing bactericidal activity against susceptible organisms.
Cardiovascular agents
Class Summary
Premedication is recommended by several sources because of the risks of allergic reaction and serum sickness with antivenom. In the presence of clear and severe clinical signs of stonefish envenomation, antivenom should not be withheld solely because of such considerations. The choice of specific premedication drugs is controversial but generally should include an antihistamine and epinephrine (when not contraindicated).
Epinephrine (EpiPen, Adrenalin)
Epinephrine is the drug of choice for the treatment of anaphylactoid reactions and should be considered as pretreatment prior to giving antivenom.
Antihistamines
Class Summary
Antihistamines are another antivenom premedication choice to minimize adverse effects.
Diphenhydramine (Benadryl)
Used for the symptomatic relief of allergic symptoms caused by histamine release in response to allergens.
Corticosteroids
Class Summary
Corticosteroids may be useful in preventing or treating serum sickness associated with antivenom use.
Hydrocortisone (Hydrocortone Phosphate, Solu-Cortef)
Prophylactic corticosteroids may prevent later serum sickness, although to date, there have been no cases reported in the literature of delayed serum sickness following any administration of marine antivenom. Hydrocortisone decreases inflammation by suppression of migration of polymorphonuclear leukocytes and reversal of increased capillary permeability.
Methylprednisolone (Solu-Medrol, Depo-Medrol)
Methylprednisolone is useful to treat inflammatory and allergic reactions. By reversing increased capillary permeability and suppressing PMN activity, it may decrease inflammation.
A multitude of corticosteroid preparations are available. Methylprednisolone is widely available in the ED owing to its other uses (eg, acute asthma, spinal cord injury) and is supplied in both parenteral and oral formulations. It is therefore discussed here as a typical drug of this class.
Immunizations
Class Summary
Tetanus results from elaboration of an exotoxin from Clostridium tetani. A booster injection in previously immunized individuals is recommended to prevent this potentially lethal syndrome. Patients who may not have been immunized against C tetani products (eg, immigrants, the elderly) should receive tetanus immune globulin (Hyper-Tet)
Diphtheria-tetanus toxoid (dT)
Diphtheria-tetanus toxoid is used for the passive immunization of any person with a wound that might be contaminated with tetanus spores.
Immunoglobulins
Class Summary
Immunoglobulins are used in previously unvaccinated individuals to provide passive immunity to tetanus when individuals become exposed.
Tetanus immune globulin (TIG)
Tetanus immune globulin is used for passive immunization of any person with a wound that might be contaminated with tetanus spores.
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Lionfish (Pterois volitans) have long, slender spines with small venom glands, and they have the least potent sting of the Scorpaenidae family. Courtesy Dee Scarr.
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Scorpionfish (genus Scorpaena) have shorter, thicker spines with larger venom glands than lionfish do, and they have a more potent sting. Courtesy Dee Scarr.
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Stonefish (genus Synanceia) have short, stout spines with highly developed venom glands, and they have a potentially fatal sting. Courtesy Paul S. Auerbach, MD.
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Members of the genera Scorpaena, such as these scorpionfish, and Synanceia, such as the stonefish, usually are found well camouflaged on the sandy bottom of the sea or amongst rocks. Shoes or booties may provide some protection; however, it is best to avoid touching the sea bottom or to use a shuffling gait while wading. Courtesy Dee Scarr.
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Members of the genus Pterois, such as this lionfish, are usually free-swimming or hovering in small caves or crevices for protection. Provoking these fish by handling or cornering them may result in a painful envenomation. Courtesy Dee Scarr.
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In defense of the animals, envenomations and injury generally occur in response to a perceived threat, usually handling or stepping on the animals. Photo by Scott A Gallagher, MD.
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A 45-year-old diver was taking photographs in Australia at a depth of 60 feet. He suddenly noticed an excruciating pain in his left foot after resting his foot on a large stonefish. Photo courtesy John Williamson, MD and Surf Lifesaving Queensland.
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Top, Brown rockfish of the Scorpaenidae family. Lateral view of the left pelvic spine in articulation with the pelvic girdle. Middle, Anterior view of left pelvic spine (proximal portion) of the brown rockfish. Bottom, Lionfish spine.
