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Jamie Seymour

Publications and source records attributed to Jamie Seymour.

8 recordsLinked to original sources

Plastic containers and the whole-blood clotting test: glass remains the best option.

This is the first study to identify normal whole-blood clotting times in various plastic containers and to identify the effect of the addition of various concentrations of Pseudechis australis (Mulga snake) venom on the clotting time in glass and plastic. Polycarbonate was identified as a potential alternative to glass as a testing container owing to a whole-blood clotting time within acceptable limits for a bedside test (mean 29.5 min) and equivalent performance to glass in the presence of P. australis venom. Other plastic containers (such as polypropylene and polyethylene) were found to be unsuitable owing to very prolonged clotting times (>60 min) or impaired performance in the presence of venom. Overall, owing to the variation between the performance of different plastics and the difficulty in differentiating between them, plastic containers cannot be recommended as an alternative to glass when performing the whole-blood clotting test for envenomed patients.

Analysis of Variance↗

Helicopter primary retrieval: tasking who should do it?

BACKGROUND: Cairns Base Hospital utilizes a helicopter retrieval system, which until 2001 had been tasked and staffed by emergency physicians. Since 2001, the ambulance service has assumed the role of both tasking and staffing the helicopter with intensive care paramedics. The present study examines whether the change has resulted in different activation patterns and patient outcomes. METHOD: A retrospective chart review over 4 consecutive years, comparing the two groups, was carried out examining 30 day mortality, length of in-hospital stay, transfer rates, the Revised Trauma Score where appropriate and rates of discharge directly from the ED. RESULTS: A total of 374 patients were retrieved (211 patients in the emergency physician group from 1 April 1999 to 31 March 2001 and 163 in the ambulance group from 1 April 2001 to 31 March 2003) over the 4 year period. The demographics of the two groups were similar. Fifty-four patients in the ambulance group (33.1%) were discharged from the ED without admission while 31 (14.7%) were discharged from the physician group. This was statistically significant (P = 0.0001). There were no other significant differences between the two groups. The subgroup of patients admitted also did not show any significant difference in outcomes. CONCLUSION: The similarities in outcomes for admitted patients support the view that both groups have similar tasking criteria for high-acuity patients and suggest that paramedics are as efficacious as physicians in delivering prehospital care in this group of patients. However, for lower-acuity patients, there is a statistically significant higher rate of clinically unnecessary taskings by the ambulance group. Given the recent fatal aeromedical accidents in Queensland (Thursday Island 1998, Rockhampton 1999 and Mackay 2003), it would seem prudent to reduce clinically unnecessary retrievals through clinical coordination with appropriately qualified emergency physicians.

Adult↗

A simple visual system without neurons in jellyfish larvae.

Earlier detailed studies of cnidarian planula larvae have revealed a simple nervous system but no eyes or identifiable light sensing structures. Here, we describe the planula of a box jellyfish, Tripedalia cystophora, and report that these larvae have an extremely simple organization with no nervous system at all. Their only advanced feature is the presence of 10-15 pigment-cup ocelli, evenly spaced across the posterior half of the larval ectoderm. The ocelli are single cell structures containing a cup of screening pigment filled with presumably photosensory microvilli. These rhabdomeric photoreceptors have no neural connections to any other cells, but each has a well-developed motor-cilium, appearing to be the only means by which light can control the behaviour of the larva. The ocelli are thus self-contained sensory-motor entities, making a nervous system superfluous.

Animals↗

Severity of Irukandji syndrome and nematocyst identification from skin scrapings.

OBJECTIVES: (1) To identify the causative jellyfish species by examining skin scrapings in patients presenting to Cairns Base Hospital with marine stings, and (2) to describe clinical outcomes of those with Irukandji syndrome and those in whom nematocysts were identified from skin scrapings. DESIGN AND SETTING: (1) A retrospective case series of 128 patients, identified from Cairns Base Hospital emergency department records with discharge diagnoses of marine stings between 1 July 2001 and 30 June 2002. (2) A prospective study of skin scrapings from 50 patients presenting with marine stings from the same period. MAIN OUTCOME MEASURES: Number of patients with Irukandji syndrome, their opioid requirements and cardiac findings (where available); identification of causative species from nematocysts isolated from skin scrapings. RESULTS: 116 patients retrospectively identified with marine stings had Irukandji syndrome. Of 50 patients who had skin scrapings, 39 had nematocysts consistent with Carukia barnesi. Symptoms experienced ranged from local pain alone to severe Irukandji syndrome with elevated troponin I levels, changes on electrocardiogram, cardiac dysfunction on echocardiography, and high opioid dose requirements. One patient had an unidentified cnidome on his skin scraping. He developed severe Irukandji syndrome and subsequently died from its complications. CONCLUSION: This is the first published report of Carukia barnesi being successfully identified from skin scrapings. Most patients with identifiable cnidomes experiencing Irukandji syndrome were stung by Carukia barnesi, which we show causes a wide range of illness, including cardiac dysfunction. Our finding of a cnidome not consistent with Carukia barnesi in the setting of Irukandji syndrome makes it possible that other species of jellyfish may also cause this syndrome.

Adult↗

The use of pressure immobilization bandages in the first aid management of cubozoan envenomings.

This study is aimed to evaluate whether the application of pressure results in additional release of venom from naturally discharged, vinegar soaked nematocysts of the box jellyfish Chironex fleckeri. The results show that large quantities of venom are expressed with the application of pressures similar to that applied by compression immobilization bandages. The volume of venom expressed by this pressure was similar to the quantity expressed upon initial natural discharge of the nematocysts. The current recommended practice of applying PIB to cubozoan stings might worsen the envenomation. As the existing data now show that PIB may be detrimental to victims envenomed by cubozoans, we suggest that the current practice of the use of PIB in cubozoan envenomings be discarded until there is direct experimental evidence to support its use.

Acetic Acid↗

A sting from an unknown jellyfish species associated with persistent symptoms and raised troponin I levels.

We describe a patient stung by an unknown jellyfish species offshore in Far North Queensland. The sting caused immediate and severe pain, multiple whip-like skin lesions and constitutional symptoms. The jellyfish tentacular nematocysyts were similar to, but distinct from, those of Carukia barnesi, a cause of the 'Irukandji' syndrome. The patients symptoms largely resolved over seven months and were associated with elevated cardiac troponin levels, in the absence of other evidence of cardiac disease. This case highlights the envenomation risks associated with marine recreation, and the need for critical evaluation of cardiac troponin assays and for further research in marine toxicology.

Adult↗