Early Experience with Magnesium Administration in Irukandji Syndrome

Immunological Responses to Envenomation

Venoms are complex mixtures of toxic compounds delivered by bite or sting. In humans, the consequences of envenomation range from self-limiting to lethal. Critical host defence against envenomation comprises innate and adaptive immune strategies targeted towards venom detection, neutralisation, detoxification, and symptom resolution. In some instances, venoms mediate immune dysregulation that contributes to symptom severity. This review details the involvement of immune cell subtypes and mediators, particularly of the dermis, in host resistance and venom-induced immunopathology. We further discuss established venom-associated immunopathology, including allergy and systemic inflammation, and investigate Irukandji syndrome as a potential systemic inflammatory response. Finally, this review characterises venom-derived compounds as a source of immune modulating drugs for treatment of disease.

Non-invasive assessment of the cardiac effects of Chironex fleckeri and Carukia barnesi venoms in mice, using pulse wave doppler

Both Chironex fleckeri venom (CFV) and Carukia barnesi venoms (CBV) are known to cause significant cardiac morbidity and mortality. Many animal studies have demonstrated cardiac dysfunction with these venoms. This study specifically examines the systolic and diastolic cardiac functions using non-invasive pulse wave doppler. Mitral and aortic doppler sonograms of anaesthetised mice were obtained utilising a 10 MHz doppler probe. These continuous sonograms were analysed to ascertain changes in cardiac function before and after the parenteral administration of the test venoms. We found that CFV administration causes rapid cardiac dysfunction without a change in heart rate. Analysis of the resulting sonograms shows both systolic and diastolic dysfunction which together is suggestive of a progressively poorly compliant, contracted left ventricle. Additionally, the rapidity of cardiac dysfunction suggests a direct effect of CFV on myocardial cells. In contrast CBV showed a moderate immediate inotropic and chronotropic effect that was sustained until precipitous cardiac decompensation. This is consistent with the hypotheses of a toxin induced stress cardiomyopathy from sustained catecholaminergic activity.

Review article: Role of magnesium sulphate in the management of Irukandji syndrome: A systematic review

Signs of Irukandji syndrome (IS) suggest an underlying catecholamine storm with research demonstrating that Carukia barnesi venom causes a significant rise in adrenaline/noradrenaline serum levels. A systematic review was undertaken to ascertain the current evidence in treating IS with magnesium salts. A literature search was conducted using Scopus, Medline and ScienceDirect. Further articles were discarded via title description and/or abstract details. The remaining were read in full, and those identified as not having sufficient information regarding magnesium and patient outcomes were removed. Nine articles were identified. One article was a randomised controlled trial, which concluded that there appears to be no beneficial difference between those patients who received the magnesium sulphate (MgSO₄ ) and those who received the placebo and recommended against the use of MgSO₄ in IS. Of the remaining eight, one reported the failure of MgSO₄ and the remaining seven were case series reporting varying success in its use. This systematic review found insufficient evidence to support any clear recommendation regarding the use of magnesium, but nor was there clear evidence to recommend against its use in IS. Two case series describe significant reduction in key symptoms and hypertension but are a non-randomised albeit prospective series with the limitations accompanying this. The reporting of recrudescence of symptoms with reduction of dose does suggest a dose-response relationship. The evidence for the use of MgSO₄ is at best anecdotal, and further research is required to either confirm its benefit or confirm the randomised controlled trial.

Biology and ecology of Irukandji jellyfish (Cnidaria: Cubozoa)

Irukandji stings are a leading occupational health and safety issue for marine industries in tropical Australia and an emerging problem elsewhere in the Indo-Pacific and Caribbean. Their mild initial sting frequently results in debilitating illness, involving signs of sympathetic excess including excruciating pain, sweating, nausea and vomiting, hypertension and a feeling of impending doom; some cases also experience acute heart failure and pulmonary oedema. These jellyfish are typically small and nearly invisible, and their infestations are generally mysterious, making them scary to the general public, irresistible to the media, and disastrous for tourism. Research into these fascinating species has been largely driven by the medical profession and focused on treatment. Biological and ecological information is surprisingly sparse, and is scattered through grey literature or buried in dispersed publications, hampering understanding. Given that long-term climate forecasts tend toward conditions favourable to jellyfish ecology, that long-term legal forecasts tend toward increasing duty-of-care obligations, and that bioprospecting opportunities exist in the powerful Irukandji toxins, there is a clear need for information to help inform global research and robust management solutions. We synthesise and contextualise available information on Irukandji taxonomy, phylogeny, reproduction, vision, behaviour, feeding, distribution, seasonality, toxins, and safety. Despite Australia dominating the research in this area, there are probably well over 25 species worldwide that cause the syndrome and it is an understudied problem in the developing world. Major gaps in knowledge are identified for future research: our lack of clarity on the socio-economic impacts, and our need for time series and spatial surveys of the species, make this field particularly enticing.

Randomised trial of magnesium in the treatment of Irukandji syndrome

OBJECTIVES

Irukandji syndrome is a distressing condition characterised by pain, hypertension and tachycardia. Some develop cardiac failure and there have been two reported deaths. Magnesium sulphate has become the standard of care despite minimal evidence. The aim of this study was to investigate if magnesium would reduce analgesic requirement and length of stay for patients with Irukandji syndrome.

METHODS

This was a double-blind, randomised controlled clinical trial. Patients with Irukandji syndrome who required parenteral opioid analgesia were randomised to receive either 10 mmol of magnesium as a bolus, and then a 5 mmol/h magnesium infusion for 6 h or saline. Fentanyl patient-controlled analgesia was commenced to allow patients to self-regulate their pain relief. The primary outcome measure of the study was comparison of total analgesic requirements between the two groups. The secondary outcome measure was to compare length of stay.

RESULTS

The study ran from November 2003 to May 2007. Thirty-nine patients were enrolled in the study; 26 were male with a median age of 28. Twenty-two received magnesium. There was no significant difference in the morphine equivalent dose used, peak CK, peak troponin, peak pulse, peak blood pressure, peak mean arterial pressure (MAP), percentage MAP rise and length of stay for those receiving magnesium compared with placebo.

CONCLUSION

Our study did not demonstrate a benefit in the use of magnesium in the treatment of Irukandji syndrome. As such the current use of magnesium needs to be reconsidered until there is good evidence to support its use.

Australian carybdeid jellyfish causing "Irukandji syndrome"

The Australian carybdeid jellyfish associated with Irukandji syndrome is Carukia barnesi, (Barnes' jellyfish). Other Australian carybdeid jellyfish that may be associated with the syndrome include Carukia shinju, Carybdea xaymacana, Malo maxima, Malo kingi, Alatina mordens, Gerongia rifkinae, and Morbakka fenneri ("Morbakka"). These small jellyfish are difficult to capture and identify. They are located offshore of the coasts of Australian states including Queensland, The Northern Territory, Western Australia and South Australia. The syndromic illness, resulting from a characteristic relatively minor sting, develops after about 30 minutes and consists of severe muscle pains especially of the lower back, muscle cramps, vomiting, sweating, agitation, vasoconstriction, prostration, hypertension and in cases of severe envenomation, acute heart failure. The mechanisms of actions of their toxins are obscure but they appear to include modulation of neuronal sodium channels leading to massive release of endogenous catecholamines (C. barnesi, A. mordens and M. maxima) and thereby to possible stress-induced cardiomyopathy. In addition, pore formation may occur in myocardial cellular membranes (C. xaymacana). In human cases of severe envenomation, systemic hypertension and myocardial dysfunction are associated with membrane leakage of troponin. Clinical management includes parenteral analgesia, antihypertensive therapy, oxygen and mechanical ventilation. No effective first-aid is known. Large knowledge gaps exist in biology of the jellyfish, their distribution, their toxins and mode of actions and in treatment of the Irukandji syndrome.

A pharmacological investigation of the venom extract of the Australian box jellyfish, Chironex fleckeri, in cardiac and vascular tissues

The pharmacology of Australian box jellyfish, Chironex fleckeri, unpurified (crude) nematocyst venom extract (CVE) was investigated in rat isolated cardiac and vascular tissues and in anaesthetised rats. In small mesenteric arteries CVE (0.01-30 μg/ml) caused contractions (EC(50) 1.15±0.19 μg/ml) that were unaffected by prazosin (0.1 μM), bosentan (10 μM), CGRP(8-37) (1 μM) or tetrodotoxin (1 μM). Box jellyfish antivenom (5-92.6 units/ml) caused rightward shifts of the CVE concentration-response curve with no change in the maximum. In the presence of l-NAME (100 μM) the sensitivity and maximum response to CVE were increased, whilst MgSO(4) (6 mM) decreased both parameters. CVE (1-10 μg/ml) caused inhibition of the contractile response to electrical sympathetic nerve stimulation. Left atrial responses to CVE (0.001-30 μg/ml) were bi-phasic, composed of an initial positive inotropy followed by a marked negative inotropy and atrial standstill. CVE (0.3 μg/ml) elicited a marked decrease in right atrial rate followed by atrial standstill at 3 μg/ml. These responses were unaffected by 1 μM of propranolol, atropine or CGRP(8-37). Antivenom (54 and 73 units/ml) caused rightward shifts of the CVE concentration-response curve and prevented atrial standstill in left and right atria. The effects of CVE do not appear to involve autonomic nerves, post-synaptic α(1)- or β(1)-adrenoceptors, or muscarinic, endothelin or CGRP receptors, but may occur through direct effects on the cardiac and vascular muscle. Box jellyfish antivenom was effective in attenuating CVE-induced responses in isolated cardiac and vascular tissues.

Irukandji sydrome in the Torres Strait: a series of 8 cases

OBJECTIVE

To review the presentations of a series of patients with suspected Irukandji syndrome in the Torres Strait, where the syndrome has hitherto been unknown or undocumented, in order to identify at-risk groups and improve the management of this condition in the region.

METHODS

A mixed retrospective-prospective review of eight cases of patients with suspected Irukandji syndrome in the Torres Strait, with a focus on the differences between the clinical presentations and patient outcomes.

RESULTS

Irukandji syndrome is the most likely explanation, based on current knowledge, of this series of marine envenomation syndromes in the Torres Strait. The syndrome appears to be more common in the monsoon season and young, Torres Strait Islander males likely represent a high-risk group in the region.

CONCLUSIONS

The Torres Strait can be added to the growing list of regions where Irukandji syndrome has been documented. The clinical picture, including time to onset of symptoms, constellation of symptoms and signs, analgesic requirement and time to recovery, can differ markedly between patients. There is a need for health promotion and education of health staff and the public regarding the risks, symptoms and signs of this condition. There is also a clear need for the use of case definitions and standardised management approaches for Irukandji syndrome, while the health community awaits the results of ongoing research into the pathophysiology and improved treatments for this interesting but dangerous tropical marine envenomation syndrome.

The pharmacology of Malo maxima jellyfish venom extract in isolated cardiovascular tissues: A probable cause of the Irukandji syndrome in Western Australia

The in vitro cardiac and vascular pharmacology of Malo maxima, a newly described jellyfish suspected of causing Irukandji syndrome in the Broome region of Western Australia, was investigated in rat tissues. In left atria, M. maxima crude venom extract (CVE; 1-100μg/mL) caused concentration-dependent inotropic responses which were unaffected by atropine (1μM), but significantly attenuated by tetrodotoxin (TTX; 0.1μM), propranolol (1μM), Mg(2+) (6mM) or calcitonin gene-related peptide antagonist (CGRP(8-37); 1μM). CVE caused no change in right atrial rate until 100μg/mL, which elicited bradycardia. This was unaffected by atropine, TTX, propranolol or CGRP(8-37). In the presence of Mg(2+), CVE 30-100μg/mL caused tachycardia. In small mesenteric arteries CVE caused concentration-dependent contractions (pEC(50) 1.03±0.07μg/mL) that were unaffected by prazosin (0.3μM), ω-conotoxin GVIA (0.1μM) or Mg(2+) (6mM). There was a 2-fold increase in sensitivity in the presence of CGRP(8-37) (3μM). TTX (0.1μM), box jellyfish Chironex fleckeri antivenom (92.6U/mL) and benextramine (3μM) decreased sensitivity by 2.6, 1.9 and 2.1-fold, respectively. CVE-induced maximum contractions were attenuated by C. fleckeri antivenom (-22%) or benextramine (-49%). M. maxima CVE appears to activate the sympathetic, but not parasympathetic, nervous system and to stimulate sensory nerve CGRP release in left atria and resistance arteries. These effects are consistent with the catecholamine excess thought to cause Irukandji syndrome, with additional actions of CGRP release.

'To swim or not to swim': the impact of jellyfish stings causing Irukandji Syndrome in Tropical Queensland

AIM

This manuscript presents both demographic and descriptive data related to a distressing clinical condition known as Irukandji syndrome. Chart audit and observation data were collected to explore trends in patient characteristics and to review the current practices surrounding the management of the syndrome by advanced practice ED nurses.

BACKGROUND

Irukandji syndrome, a known health emergency in northern Australia, causes severe symptoms such as muscle pains, nausea and vomiting, headache and chest pain causing clinical challenges for emergency nurses. Little is written about this condition from a nursing perspective.

DESIGN

A mixed methods case study approach.

METHODS

Data were collected by observation and chart audit from 186 patients diagnosed with Irukandji syndrome between 2001-2007.

RESULTS

Of the 186 patients, 44.1% were local residents and 58.6% were men. Median age of the patients was 27 years (range 16-77). There was a time trend with a greater number of stings occurring out at the Great Barrier Reef than at mainland beaches (p < 0.001). Important results were found regarding waiting times for pain management and intuitive rather than documented assessment practices of advanced practice nursing staff.

CONCLUSION

Irukandji syndrome causes severe emotional distress and acute pain, however, people continue to swim in marine sting environments and fail to make use of available protective clothing such as body suits. Local residents continue to be stung regardless of the educational information available suggesting a review of the current public education campaign is required.

RELEVANCE TO CLINICAL PRACTICE

Nurses failed to document assessment processes limiting adequately the ability to assess trends in the patient's condition effectively and treat symptoms efficiently. It is, therefore, timely to review the critical role that assessment plays in clinical care.

Irukandji syndrome case series from Australia's Tropical Northern Territory

STUDY OBJECTIVE

We describe Irukandji syndrome (a painful hypercatecholaminergic condition caused by jellyfish envenoming) in Australia's Northern Territory.

METHODS

We collected prospectively a standardized data set on patients presenting to health facilities in the Northern Territory. Additional cases were identified retrospectively. Data collected included demographic, geographic, seasonal, and environmental features, as well as sting details, clinical manifestations, investigations, management, and outcomes.

RESULTS

From 1990 to 2007, Irukandji syndrome affected 87 people. Age ranged from 1 to 51 years (64% male victims; 41% children [63% indigenous]). Activities associated with stings included snorkeling or scuba diving (35%) and swimming (29%). Stings commonly occurred in water greater than 2 m deep (63%), with fine weather (73%) and still or light breeze (70%). Seasonal variation was bimodal; peaks in May and October corresponded to prevailing offshore winds in the Darwin and Gove areas, respectively. Pain was severe (65%), with rapid onset (<30 minutes in 79%). Sting lesions (visible in 63%) were mild, and nematocysts (detected in 7 cases) had variable morphology. Systemic features were common, including hypertension and ECG abnormalities. Severe complications included troponin-level increases (2 cases) and cardiomyopathy with ventricular tachycardia (1 case), but no fatalities. Management included vinegar as first aid (66%), parenteral opioids (70%) (range 2 to 82.5 mg morphine equivalents in adults), and magnesium sulfate (3 cases). Hospital admission (49%) and aeromedical retrieval (16%) were commonplace.

CONCLUSION

Irukandji syndrome in the Northern Territory was clinically consistent with previous studies but had distinct seasonal, geographic, and environmental features. Indigenous children in remote coastal communities are at risk, and there is room for improvement in prevention and management.

A cell-based assay for screening of antidotes to, and antivenom against Chironex fleckeri (box jellyfish) venom

INTRODUCTION

Chironex fleckeri is a large box jellyfish that has been labelled the 'most venomous animal' in the world. We have recently shown that the primary effect of C. fleckeri venom in vivo is cardiovascular collapse. This study utilised a cell-based assay to examine the effects of C. fleckeri venom on the proliferation of a rat aortic smooth muscle cell line. In addition, the ability of CSL box jellyfish antivenom and/or various potential treatment strategies to neutralise the effects of the venom was examined.

METHODS

A7r5 cells were cultured in media containing venom. The effect of CSL box jellyfish antivenom (5 U/mL), CSL polyvalent snake antivenom (5 U/mL), lanthanum (5 microM), MgSO(4) (50 mM), verapamil (5 microM) or felodipine (5 microM) was examined. Cell viability was determined using a Cell titer 96 AQueous One Solution cell proliferation assay.

RESULTS

Incubation of A7r5 cells with serially diluted venom (2-0.004 microg/mL) caused a concentration-dependent inhibition of cell proliferation with an IC(50) value of 0.056 microg/mL. This response was not affected by the absence of calcium or the presence of lanthanum in the media. Box jellyfish antivenom (5 U/mL) prevented the inhibition of cell proliferation caused by the venom. Verapamil (5 microM) had no significant effect on the inhibition. In contrast, felodipine (5 microM) or MgSO(4) (50 mM) potentiated the effects of the venom and partially negated the protective effect of the antivenom.

DISCUSSION

This study displayed the ability to utilise a cell-based assay to determine the effects of C. fleckeri venom on vascular cell viability. It showed that CSL box jellyfish can neutralise the effects of the venom but only if added prior to the venom. In addition, potential adjunct therapies verapamil, felodipine and MgSO(4) were found to be ineffective, with felodipine and MgSO(4) potentiating the detrimental effects of the venom.

Australian venomous jellyfish, envenomation syndromes, toxins and therapy

The seas and oceans around Australia harbour numerous venomous jellyfish. Chironex fleckeri, the box jellyfish, is the most lethal causing rapid cardiorespiratory depression and although its venom has been characterised, its toxins remain to be identified. A moderately effective antivenom exists which is also partially effective against another chirodropid, Chiropsalmus sp. Numerous carybdeids, some unidentified, cause less severe illness, including Carybdea rastoni whose toxins CrTX-A and CrTX-B are large proteins. Carukia barnesi, another small carybdeid is one cause of the 'Irukandji' syndrome which includes delayed pain from severe muscle cramping, vomiting, anxiety, restlessness, sweating and prostration, and occasionally severe hypertension and acute cardiac failure. The syndrome is in part caused by release of catecholamines but the cause of heart failure is undefined. The venom contains a sodium channel modulator. Two species of Physalia are present and although one is potentially lethal, has not caused death in Australian waters. Other significant genera of jellyfish include Tamoya, Pelagia, Cyanea, Aurelia and Chyrosaora.

A probable case of Irukandji syndrome in Thailand

The Irukandji syndrome is a jellyfish envenomation caused by Carukia barnesi or related jellyfish. In literature, the distribution of "Irukandji-like" syndromes is restricted to Australia. We report a case of probable Irukandji syndrome in Thailand. With this report, we hope to promote awareness to aid sting prevention and stimulate research.

Irukandji Syndrome: What nurses need to know

Irukandji Syndrome can be frightening for the patient and make care delivery difficult for the nurse. Nurses' knowledge of Irukandji Syndrome has been limited to information provided by marine biologists, doctors, and tropical medicine specialists. This paper proposes to assist with the evolution of nursing knowledge for the care of the patient with Irukandji Syndrome. An algorithm of nursing management is presented that has been derived from the continuing debate among scientists about the etiology of signs, symptoms, and treatment rationales. Community safety and education surrounding Irukandji Syndrome requires concurrent progression of nursing knowledge and scientific inquiry.

Prospective study of Chironex fleckeri and other box jellyfish stings in the “Top End” of Australia's Northern Territory

OBJECTIVE

To describe the epidemiology and clinical features of box jellyfish envenoming in the Top End of the Northern Territory and, in particular, confirmed stings from the major Australian box jellyfish, Chironex fleckeri.

DESIGN

Prospective collection of clinical data and skin scrapings or sticky-tape tests for nematocyst identification from patients presenting to Royal Darwin Hospital and remote coastal community health clinics in the Northern Territory, spanning 10 950 km of coastline; analysis of tidal, weather and seasonal data.

PATIENTS

All patients with jellyfish sting details recorded between 1 April 1991 and 30 May 2004.

MAIN OUTCOME MEASURES

Demographic and clinical features, use of C. fleckeri antivenom, and associations between weather, seasonal and tidal factors and confirmed C. fleckeri stings.

RESULTS

Of 606 jellyfish stings documented, 225 were confirmed to have been caused by C. fleckeri. 37% of C. fleckeri stings were in children, 92% occurred during the "stinger season" (1 October to 1 June), 83% occurred in water 1 m or less deep, and 17% occurred while victims were entering the water. Stings were least common on outgoing tides (P < 0.001) and commonest between 15:00 and 18:00 (P < 0.001) and on days with wind speed less than that month's average (P < 0.001). Nearly all victims experienced immediate pain, but this could often be controlled with ice; only 30% required parenteral narcotics and 8% required hospital admission. Cardiorespiratory arrest occurred within several minutes of the sting in the one fatal case, involving a 3-year-old girl with only 1.2 m of visible tentacle contact. C. fleckeri antivenom was given to another 21 patients, none of whom had life-threatening features at the time they were given antivenom.

CONCLUSIONS

Most C. fleckeri stings are not life-threatening; patients who die usually have cardiopulmonary arrest within minutes of the sting. The potential benefit of antivenom and magnesium under these circumstances remains to be shown, but a protocol with their rapid use is recommended if cardiopulmonary arrest has occurred. Unfortunately, this is unrealistic for many rural coastal locations, and the priority remains prevention of stings by keeping people, especially children, out of the sea during the stinger season.

Cardiovascular actions of the venom from the Irukandji (Carukia barnesi) jellyfish: effects in human, rat and guinea-pig tissues in vitro and in pigs in vitro

1. We have investigated the cardiovascular pharmacology of the crude venom extract (CVE) from the potentially lethal, very small carybdeid jellyfish Carukia barnesi, in rat, guinea-pig and human isolated tissues and anaesthetized piglets. 2. In rat and guinea-pig isolated right atria, CVE (0.1-10 microg/mL) caused tachycardia in the presence of atropine (1 micromol/L), a response almost completely abolished by pretreatment with tetrodotoxin (TTX; 0.1 micromol/L). In paced left atria from guinea-pig or rat, CVE (0.1-3 microg/mL) caused a positive inotropic response in the presence of atropine (1 micromol/L). 3. In rat mesenteric small arteries, CVE (0.1-30 microg/mL) caused concentration-dependent contractions that were unaffected by 0.1 micromol/L TTX, 0.3 micromol/L prazosin or 0.1 micromol/L omega-conotoxin GVIA. 4. Neither the rat right atria tachycardic response nor the contraction of rat mesenteric arteries to CVE were affected by the presence of box jellyfish (Chironex fleckeri) antivenom (92.6 units/mL). 5. In human isolated driven right atrial trabeculae muscle strips, CVE (10 microg/mL) tended to cause an initial fall, followed by a more sustained increase, in contractile force. In the presence of atropine (1 micromol/L), CVE only caused a positive inotropic response. In separate experiments in the presence of propranolol (0.2 micromol/L), the negative inotropic effect of CVE was enhanced, whereas the positive inotropic response was markedly decreased. 6. In anaesthetized piglets, CVE (67 microg/kg, i.v.) caused sustained tachycardia and systemic and pulmonary hypertension. Venous blood samples demonstrated a marked elevation in circulating levels of noradrenaline and adrenaline. 7. We conclude that C. barnesi venom may contain a neural sodium channel activator (blocked by TTX) that, in isolated atrial tissue (and in vivo), causes the release of transmitter (and circulating) catecholamines. The venom may also contain a 'direct' vasoconstrictor component. These observations explain, at least in part, the clinical features of the potentially deadly Irukandji syndrome.

Irukandji syndrome in northern Western Australia: an emerging health problem

OBJECTIVES

(1) To assess the number and severity of episodes of Irukandji syndrome in Broome, Western Australia. (2) To correlate demographic, seasonal, geographic and climatic features of Irukandji stings. (3) To assess treatment of Irukandji syndrome at Broome Health Service. (4) To assess the public health impact.

DESIGN AND SETTING

(1) A retrospective analysis of jellyfish data forms and charts of 111 patients, identified from Broome Health Service Emergency Department with a discharge diagnosis of marine sting between 1 January 2001 and 1 July 2003. (2) Correlation between climate and Irukandji envenomation data.

MAIN OUTCOME MEASURES

Number of patients with Irukandji syndrome; their demographic and environmental features; the clinical syndrome; treatment requirements.

RESULTS

111 patients were prospectively identified with marine stings; 88 were identified with Irukandji syndrome. Non-Irukandji syndrome data were excluded for analysis. The "jellyfish season" extends from January to May, although stings occur all year round. Only 38% of patients had vinegar applied to the sting site before hospital presentation. Signs and symptoms were variable between individuals, with 20% having no signs of sting at all and welts found in 16%. Fifty per cent of patients were hypertensive at presentation. Distress was found in the majority of patients, with 90% requiring opioid analgesia (morphine equivalent: mean, 20 mg; median, 13 mg) and 17% requiring admission. There was one evacuation to Perth with cardiotoxic marine envenomation resulting in pulmonary oedema, which necessitated 4 days in intensive care. Stings were significantly more common when the ambient median temperature was greater than 28.3 degrees C, after midday, on an incoming high tide and on windy days.

CONCLUSION

The rate of envenomation in northern WA is likely to be the highest currently documented in Australia. There is syndromic variability when compared with the north Queensland experience. This implies different causative jellyfish species that are not yet identified. Stings in Broome can be severe and life threatening; there are significant commercial and public health implications as a result. Management at Broome Hospital is contemporary and effective.