 | Viet Tran The often forgotten child of undersea related problems. Here we take a look at the more deadly things that lurk in the sea, because that knee pain might be from a tentacle rather than musculoskeletal DCS... |
Summary
- Antivenom exists for Box Jellyfish, Stonefish & Sea Snakes
- Deadly paralytic stings come from Box Jellyfish (heart), Blue Ring Octopus (skeletal muscle) and Cone Shell (skeletal muscle)
- First aid should include warm water, analgesia and cleaning with wound
- Consider Abx if at risk: diabetes, immunocompromised, joint/tendon involvement, inappropriate first aid
Box Jelly Fish
- Anatomy: 24 eyes that see 360 degrees, made of 96% water, tentacles form GIT (have a fine lumen)
- Kills in < 3 min: typical story is sting, run onto beach and collapse in asystole
- Cardiac arrest noted to be in systole - thought to be due to Ca influx (but ecg looks more like Na channel block)
Presentation
- Frost-like tenticle pattern
- Cardiac arrest from myocardial paralysis
Management
- First Aid: Ice (although recent lit suggests heat), oral analgesia, compression bandage not indicated
- Remove tentacles: ice, wet sand or vinegar can help
- Analgesia: oral, IV, block (if still in a lot of pain can consider 3 vials of antivenom)
- Cardiac Arrest: Prolonged CPR (paralysis will wear off), MgSO4, 6 vials of antivenom
Irukandji Syndrome
- A syndrome from jellyfish stings not limited to Irukandji
- Found along reef as well as coast (Box jellyfish only on coast)
Presentation
- Only small contact with tentacle required
- Onset can be delayed
- Severe pain (eg loin like renal colic)
- Mental: Restless, agitated, impending doom
- Intracranial haemorraghe has been previously reported
- Pulmonary oedema
- Anything more serious less common
Treatment
- First Aid: same as box
- Analgesia: Fentynl just in case becomes haemodynamically unstable
- Mg
- BP control early (given potential for ICH) - use GTN (fast on-off) rather than beta-blocker
- Clonidine for agitation, 50 mcg (1 mcg/kg)
- No antivenom
Paralytics
Blue Ring Octupus
- 20cm wide, 100g, timid - most stings from handling
- Bite injects a tetrodotoxin (Na channel blocker) -> neuromuscular paralysis
Presentation
- Vomiting
- Weakness
- Paralysis
- Consciousness maintained
- Pupils can be fixed and dilated
Management
- ABC +/- pressure bandage (? may make worse)
- Supportive management, paralysis usually wears off after 24 hrs
- No antivenom
Cone Shells
- Found in pacific ocean and incidence of stings are rare
- Symptoms: a barb injecting and lodging in the skin, paraesthesia progresses quickly
- Treatment is largely supportive
Spines
Stonefish
- Defensive creature - so usually stepped on
- Barbs exist on spine and seen in both fresh and salt water
- Venom normally hurts (doesn't kill)
Treatment
- hot water (45 degrees for 60 min)
- IV analgesia, nerve block, consider antivenom if not improving - 1 ampoule IM/IV per 2 sting sites
- ABx if indicated (see below)
- Clean the wound
Sting Rays
- High risk of infection
- Spine on tail contains venom
Treatment
- Hot water
- Regional block
- Remove & irrigate
- Allow delayed primary closure
- ABx if indicated (see below)
Sea Snakes
- contains both mycotoxin & neurotoxin
- Toxicology behaves like land snakes - nausea, vomiting, rhabdomyolysis, coagulopathy, paralysis
- Often occurs due to handling
Treatment
- Supportive
- Pressure bandage
- Antivenom (note that polyvalent antivenom will not cover this)
Antibiotic Indications
- Diabetic or Immunosuppressed
- Penetrating Joint or Tendon
- Wounds not initially cleaned or managed appropriately
- Established infection
