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Poisonous animals
 
Cnidarians (Jellyfish, Corals and Anemones)
 
Venomous fish
 
Scorpions
 
Spiders
 
Hymenopterans (Bees, Wasps and Ants)
 
Sea snakes
 
Terrestrial snakes
 
Miscellaneous animals
 
 
 
 
 
 
 
 

Diagnosis & Treatment — First aid / lay people

 

General problems

  • The patient is in the water (risk of drowning),
  • pain,
  • fear,
  • loss of consciousness.
F  First Aid
  • Take the patient to land.
  • Pain management (see below).
  • Calm the patient.
  • Place the patient in a stable lateral position, or possibly the Trendelenburg position (shock position).
C  Comments

Severe pain following stings from certain jellyfish as well as anxiety (fear of death) play an important role and have an additional negative influence on the clinical course after an accident.

Loss of consciousness after an accident with a venomous animal can have many causes. It is important to place the patient in a stable lateral position to avoid aspiration. Apart from the extremely rapid onset of life-threatening effects of the venom after stings from certain jellyfish, respiratory or cardiovascular complications may also be caused by drowning or near-drowning. 

If peripheral circulatory failure is present, the shock position may improve the patient's condition. If resuscitation is necessary, it is only in exceptional cases that lay people will be sufficiently well trained to be able to intervene.

Risk that the rescuer may also be stung

D  Diagnostics

Those that assist a sting victim must avoid contact with the animal that caused the sting, or parts of it, in particular tentacles that remain attached to the victim, as long as the nematocysts have not yet been inactivated.

Which cnidarian stings are dangerous?

D  Diagnostics

Box jellyfish stings:

  • Chironex fleckeri/Chiropsalmus quadrigatus (tropical and subtropical Indo-Pacific),
  • Carukia barnesi (Indo-Pacific),
  • possibly other Box jellyfish (Tamoya sp.).

Stings from:

  • Physalia sp. (tropical Atlantic, Mediterranean, Indo-Pacific),
  • other jellyfish that cause systemic symptoms of envenoming.

How can such cnidarian stings be recognised by lay people?

D  Diagnostics
  • By specific sting marks on the patients' skin ("prints", see Fig. 4.11).
  • By the occurrence of systemic signs of envenoming: respiratory and cardiovascular symptoms, muscle pain.
C  Comments

Note: if systemic envenoming occurs, it does so more or less immediately in virtually all cases, with one exception. Carukia barnesi causes the so-called "Irukandji syndrome", which occurs approximately 30 minutes (5-40 minutes) after an initially harmless local reaction (Fenner 2000).

Inactivation of the nematocysts

1. Box jellyfish

  • Chironex fleckeri/Chiropsalmus quadrigatus,
  • Carukia barnesi,
  • Tamoya sp.
F  First Aid

Douse the affected area of skin with at least 2 litres of vinegar (4–6% acetic acid, e.g. household vinegar) for at least 30 s. Subsequently remove any tentacles still attached to the skin.

For Australia see Australian Resuscitation Council website: Guideline 9.4.5 Envenomation - Jellyfish Stings

2. Physalia sp.

F  First Aid

Hot water (no hotter than the patient can comfortably tolerate; max. 45°C) immersion of the stung skin area for 20 minutes (shown for Physalia sp. stings in Australia). For Australia see Australian Resuscitation Council website: Guideline 9.4.5 Envenomation - Jellyfish Stings

3. All other cnidarians

F  First Aid

Careful manual removal of attached tentacles, washing them off with the help of seawater. Cold packs.

Hot water (no hotter than the patient can comfortably tolerate; max. 45°C) immersion of the stung skin area for 20 minutes . If local pain is unrelieved by heat, or if hot water is not available, apply a cold pack or ice in a dry plastic bag (recommended for Non-tropical Australia).

For Australia see Australian Resuscitation Council website: Guideline 9.4.5 Envenomation - Jellyfish Stings


C  Comments

There is still no universally effective means of inactivating nematocysts. Inactivating substances are highly species-specific. Thus vinegar (4–6% acetic acid) is highly effective for the inactivation of Box jellyfish nematocysts, such as Chironex fleckeri (Hartwig et al. 1980), while in Physalia physalis it causes a massive discharge of the nematocysts (Exton 1988, Fenner et al. 1993). Several substances that have been proposed and tested in certain species of cnidarians are indeed effective to a certain degree, but are generally not readily available in the real-life conditions in which such a sting occurs, e.g. baking soda, magnesium sulphate.

In any event, measures to stabilise the patient's vital functions take precedence over any attempts to inactivate nematocysts or remove tentacles. Inactivation of nematocysts with vinegar and removal of tentacles is unqualifiedly recommended following stings by Chironex fleckeri, Chiropsalmus quadrigatus and Carukia barnesi (Burnett 1991, Fenner et al. 1993, Australian Resuscitation Council website: Guideline 9.4.5 Envenomation - Jellyfish Stings).

Hot water (45°C) immersion for the teatment of Physalia sp. stings in Australia has been shown to be effective for pain relief possibly on the basis of heat inactivation of the venom (Loten et al 2006).

How can absorption and circulation of the venom be delayed?

Box jellyfish

  • Chironex fleckeri/Chiropsalmus quadrigatus,
  • Carukia barnesi,
  • possibly other Box jellyfish.
F  First Aid

Immobilise the patient. No physical exertion during transport.

Compression-immobilisation method is not recommended (Little 2001, Australian Resuscitation Council website: Guideline 9.4.8 Envenomation - Pressure Immobilisation Technique)

Pain

1. Chironex fleckeri/Chiropsalmus quadrigatus

F  First Aid

Apply cold packs or ice in dry plastic bag after inactivation of the nematocysts and removal of attached tentacles. Do not allow fresh water directly onto the sting, it may cause discharge of undischarged nematocysts. Care needs to be taken that no ice burns are caused (Exton et al. 1989, Fenner et al. 1993, Australian Resuscitation Council website: Guideline 9.4.5 Envenomation - Jellyfish Stings).

2. Physalia sp.

F  First Aid

Hot water (no hotter than the patient can comfortably tolerate; max. 45°C) immersion of the stung skin area for 20 minutes (shown for Physalia sp. stings in Australia). If this fails, apply cold packs or ice in dry plastic bag. Do not allow fresh water directly onto the sting, it may cause discharge of undischarged nematocysts. Care needs to be taken that no ice burns are caused (Exton et al. 1989, Fenner et al. 1993, Australian Resuscitation Council website: Guideline 9.4.5 Envenomation - Jellyfish Stings).

3. All other cnidarians

F  First Aid

Application of cold packs or ice after removal of attached tentacles (Exton et al. 1989, Fenner et al. 1993); however, the success of this method for some cnidarian stings has been questioned (Burnett 1991).

Which patients need to be seen by a doctor or hospitalised?

D  Diagnostics

Patients with

  • a "major sting" from Chironex fleckeri/Chiropsalmus quadrigatus
  • a Carukia barnesi sting,
  • a Physalia sp. sting,
  • systemic signs of envenoming, including systemic allergic reactions following the sting.
C  Comments

Definition of a "major sting": decreased consciousness and/or >50% of an extremity affected.

Average time between the sting and death

Chironex fleckeri/Chiropsalmus quadrigatus: minutes.
Physalia physalis: minutes.
Carukia barnesi: can be delayed due to late onset of envenoming.
All jellyfish: minutes (if the patient is sensitised and anaphylactic shock occurs).

Rapid onset of life-threatening envenoming

F  First Aid
C  Comments

The dynamics of severe envenoming necessitate the immediate use of life-saving measures at the site of the accident. For this reason, mobile strategies for the initial treatment of victims have been developed in Australia. Paramedics, i.e. ambulance teams, are trained to recognise Chironex stings, to apply first aid measures, to determine whether antivenom administration is indicated and to administer antivenom i.m.  (Beadnell et al. 1992, Fenner et al. 1989a).