Jellyfish have cells called cnidocytes, which contain nematocysts, and located usually on their tentacles, mainly. Whenever a prey comes in contact with cnidocytes, hundreds to thousands of nematocysts’ filaments are ejected into the prey’s direction. These stinging cells are thus able to latch onto the prey, and the tentacles, or the oral arms (developed from the manubrium) bring the prey item into their mouth for digestion. Nutrients then pass along the animal’s radial canals to the various tissues of the body.

Thanks for your detailed comment. I don’t disagree with your comment in any substantial way. However, except for emphasizing that vinegar should be applied first -- a point that does deserve emphasis -- I am not sure in what way you disagree with the management plan described.

I am also familiar with Bart’s management protocol in Darwin -- as I have also lived and worked there for a couple of years and have coauthoured a paper on jellyfish envenoming with him -- and it doesn’t differ substantially from the advice given on this site.

You are right to point out the absence of evidence for the administration of antivenom and magnesium. However, if a patient is in dire straits I doubt the majority of toxicologists and emergency docs in Australia would hesitate to administer these therapies, although it is important not to get distracted from the essentials of good resuscitation. As for magnesium, no one really knows if or how it might work or what the indications should be…

Cheers,
Chris

Thanks for your detailed comment. I don’t disagree with your comment in any substantial way. However, except for emphasizing that vinegar should be applied first -- a point that does deserve emphasis -- I am not sure in what way you disagree with the management plan described.

I am also familiar with Bart’s management protocol in Darwin -- as I have also lived and worked there for a couple of years and have coauthoured a paper on jellyfish envenoming with him -- and it doesn’t differ substantially from the advice given on this site.

You are right to point out the absence of evidence for the administration of antivenom and magnesium. However, if a patient is in dire straits I doubt the majority of toxicologists and emergency docs in Australia would hesitate to administer these therapies, although it is important not to get distracted from the essentials of good resuscitation. As for magnesium, no one really knows if or how it might work or what the indications should be…

Cheers,
Chris

The management strategies that actually benefit the patient the most are:

1. Copius vinegar poured over any visible tentacles still attached to the individual just envenomed

This is imperative, as the vinegar inactivates the nematocysts (the stinging cells) from releasing more venom. DO NOT first apply ice, as suggested in the management paln, as this will actually have the REVERSE effect -- it will cause the nematocysts to fire, thus increasing the venom serum dose, and increasing the likelihood of cardio-toxicity.

2. Antivenom

There is actually a lot of debate as to whether the anti-venom works. after discussion with leading Chironex researchers in Darwin, it appears that you either die pretty much instantly (last death in the NT was December 2007, a child from the neighbouring Tiwi Islands), or not at all. If your patient has collapsed, they require BLS +/- ALS. The anti-venom may be a useful adjunct for analgesia (see point 3 below). This is currently being further investigated.

3. Analgesia

These stings hurt. A lot. Give adequate analgesia, ie opioids. You can try ice, or a hot (warm) bath -- neither will really work. There is a study currently underway by Assoc. Prof Bart Currie (FRACP), who is the leading physician investigating box jellies and their envenoming. He is based in Darwin, both as an ID physician and as a researcher at Menzies, and also Dr Geoff Ibister, a leading toxinologist based in Newcastle, NSW.

4. MgSO4.

Magnesium has been used in envenoming as an analgesic adjunct, not as a cardiac stabiliser. Its use is controversial. In my experience, it doesn’t actually work. This is currently also under investigation by Dr Currie et al.

5. Steroids (for the rash).

THe welts often scar. Steroid use (systemic or oral) is NOT indicated in the acute phase of the envenomation. For the majority of patients (such as my husband) who develop the pruritic delayed hypersensitivity reaction, a steroid cream is useful to manage the extreme itch, that keeps the patient (and their spouse) awake at night!

Finally -- Vinegar + BLS = life saved.