1. Finger injury TS Au PYNEH Toxicology Case Presentation

2. Case presentation  M/32 good PH  Rt M/F finger injury – stung by the tail of a fish while washing the fresh water tank at home at 3AM  Intense burning sensation with numbness, & acute swelling at the involved finger  Triage : BP 109/49, Pulse 86, Temp 36.1 ℃, RR 16/min (at 03:33) – Cat. IV  ATT first dose given

3. Clinical photo What is it?

4. Progress in AED  Pethidine IMI (pain not relieved)  Rt hand immersed in hot tap water as tolerated as possible → immediate effect but not long-lasting until 75 min  XR of right M/F: no FB seen  No FB seen at wound exploration  Antibiotic: ciproxin 500 mg BD started

5. Progress  Stayed at O ward till next day  Pain can now be tolerated  Swelling: slightly decrease in size  Discharged with dologesic, piriton, & ciproxin and continue QD dressing in GOPD

6. Stingray injury

7. Stingray ( 魔鬼魚 )  Widely distributed in tropical to temperate waters  Not aggressive  Injury usually occurs when a swimmer or diver accidentally steps on it  One of the most common dive- and beach- related injuries

8. Pathoanatomy  A flat body + a long slender tail with sharp serrated spines (stingers)  There are 1 or more barbed stingers and 2 ventrolateral venom-containing grooves that are encased in an integumentary sheath  Stinger apparatus injects a heat labile protein-based toxin  Injury may occur without envenomation because many stingrays lose or tear the sheath of the venom glands

9. Clinical features (local)  Immediate and intense pain radiating up proximally and lasting up to 48 hours  Edema, erythema, petechiae  Local skin necrosis, extent depending on different species and areas

10. Case reports  2 cases of extensive tissue necrosis: reported in Australia (Barss P, 1984), wound exploration and debridement required  1 case of femoral pseudoaneurysm (Campell J, et al, 2003) with graft failure due to tissue necrosis, repair surgery finally required

11. Clinical effects (systemic)  Systemic effects of envenomation: nausea & vomiting, abdominal cramps, diaphoresis, dyspnoea, syncope, headache, convulsion, muscle weakness, muscle fasciculations, hypotension, & arrhythmia  Rarely fatal: due to profuse wound bleeding or direct penetration to vital organs

12. Fatal case  One fatal case was reported in Australia due to penetrating chest wall injury of a M/12 resulting in cardiac tamponade (Fenner PJ, et al, 1989).  Venom-induced myocardial necrosis occurred, leading to spontaneous myocardial perforation 6 days after injury

13. Stingray Envenomation – 1  Study of clinical effects in 84 cases of freshwater stingray injuries in Brazil (Haddad Jr V et al, 2004)  Intense pain – commonest symptom  Tissue necrosis – high percentage, mostly fishermen  Tx of immersion in hot water was effective in initial phase of envenomation; but this does not prevent skin necrosis

14. Stingray Envenomation – 2  Chemical analysis of a fresh water stingray (Potamotrygon falkneri) extract was done by polyacrylamide gel electrophoresis (PAGE)  Consists of multiple components of high molecular weight, (12 kDa – 100 kDa) with gelatinolytic, caseinolytic & hyaluronidase activities  The result showed the local clinical features can be partially explained by these enzymes

15. Complications  Anaphylaxis  Infections : mainly staphylococci & streptococci, other pathogens are not uncommon: Aeromonas species in freshwater or Vibrio species in saltwater

16. Investigation  Plain X Ray: Identify any FB, e.g. retained spine(s), which are typically radio-opaque. (Perkins RA, 2004)  Clinical picture: a spine removed from a wound (different pt)

17. Management – aim  Resuscitate for anaphylaxis  Aims to reverse the local and systemic effects of the venom: pain relief and prevention of infection  Other considerations: antitetanus prophylaxis

18. Management – Pain relief  Immersion of the injured extremity in hot water, preferably 42-45°C (110-115°F) as hot as the patient can tolerate but should not cause burns Immersion duration: 30 – 90 minutes: need to add more hot water as it cools  Evidence level C: expert opinion/consensus guidelines (Isbister G K. Am J Em Med, 2001)

19. Management – Wound Tx - Flush wound with fresh water (prehospital) - Removal of any FB: spine / sand - Debridement: prevent secondary infection - Avoid primary suturing - Daily dressing - Tetanus prophylaxis - Antibiotics

20. Antibiotic prophylaxis  Optimal coverage for Staphylococci, Streptococci, and pathogens expected in the involved water: 1. Freshwater: Aeromonas species 2. Saltwater: Vibrio species  Antibiotics of choice: quinolones (ciprofloxacin, levofloxacin), doxycycline, septrin, cefuroxime or other late-generation cephalosporins  Duration: a short course (5 days)

21. Heat treatment – widely accepted as effective initial Mx for envenomation of :  Scorpaenidae: 1. Lionfish 2. Scorpionfish 3. Stonefish  Echinoderms  Other venomous spine injuries Low High Toxic potency

22. References – 1  www.emedicine.com www.emedicine.com  Barss P. Wound necrosis caused by the venom of stingrays. Pathological findings and surgical management. Medical Journal of Australia 1984; 141: 854-5.  Campell J, Grenon K, You CK. Pseudoaneurysm of the superficial femoral artery resulting from stingray envenomation. Annals of Vascular Surgery 2003; 17(2): 217-220.  Fenner PJ, Williamson JA, Skinner RA. Fatal and non-fatal stingray envenomation. Medical Journal of Australia 1989; 151: 621-5.

23. References – 2  Haddad Jr V, et al. Freshwater stingrays: Study of epidemiologic, clinic and therapeutic aspects based on 84 envenomings in humans and some enzymatic activities of the venom. Toxicon 2004; 43(3): 287-294.  RJ Evans, RS Davies. Stingray injuries. Journal of Accident and Emergency Medicine 1996;13:224-5.  R Allen Perkins, Shannon S Morgan. Poisoning, envenomation, and trauma from marine creatures. American Family Physician 2004; 69(4): 885-890.  Isbister GK. Venomous fish stings in tropical northern Australia. American Journal of Emergency Medicine 2001; 19: 561-5.

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