INTRODUCTION

Clinical call handlers use a clinical decision support software system (CDSS) called the Emergency Communication Nurse System™ (ECNS™) to further triage calls considered eligible for secondary triage post the interaction the patient or caller had with the Emergency Medical Dispatcher (EMD). EMDs use a primary emergency triage system called Medical Priority Dispatch System (MPDS®) to triage callers accessing 911 services.

This call involved a teenage boy calling 999 in England, UK, on behalf of his friend (also a teenage boy) who was stung on the palmar side of his right wrist by a pet stingray. Stingrays belong to a group of eight families of rays in the Myliobatoidei suborder and not known to be aggressive other than when stepped on or cornered. He was busy moving the stingray from one tank to another when the unfortunate incident happened. The call was classified by the EMD on an Envenomation (Stings/Bites) dispatch protocol as a 2A02 determinant (No difficulty breathing or swallowing with symptoms present for less than 1 hour) and referred the call to a registered nurse (RN) for further triage.

As per protocol the Registered Nurse (RN) first verified with the patient if there were any life-threatening symptoms present. It turned out the teenager was stung 5 minutes ago, the stinger was not left in situ, there was no active bleeding present (the bleeding that was present at the time of the sting stopped) and the main symptoms now were sweating, agonizing pain, redness and swelling around the right wrist with an inability to move his fingers distal to the sting area.

These are typical symptoms encountered after a stingray sting. A barbed stinger attached to a venom gland are located on the distal end of the stingray's tail and during a sting venom can be injected into the wound–difficult to believe stingray venom once was used as anesthetic in ancient Greece.

Management and Outcome

This is NOT one of the typical run-of-the-mill scenarios our clinicians deal with on a daily basis, nor is it a scenario one expects to encounter too often in rural East Anglia.

The RN handled this call very well, ruling out life-threatening conditions first, e.g. symptoms of anaphylaxis and any potential serious hemorrhage from the sting in the palmar wrist area as well as confirming the presence of any co-morbid conditions, allergies and current medication use. After a few more triage questions she reached a disposition whereby she selected to send an ambulance to the home of these two teenagers as they had no one there to take them to the Emergency Department (ED). The area of the sting was considered to fall in one of the 'critical' body areas considering the number of neurovascular and tendinous structures present in the palmar aspect of the wrist.

The RN gave interim self-care instructions which started with hot water immersion (HWI) instructions as per the protocol "… have you got anywhere that you can fill up a bowl with hot water so he can soak his wrist in there?"; "… it needs to be quite hot, but not hot enough to burn". "… keep soaking it in there until the ambulance comes…". She also suggested some simple analgesia which he had at home: "you can get him some paracetamol (acetaminophen) as well, while he is waiting…". In case he started to bleed again from the puncture wound in his wrist while submerged in the hot water she added: "If it starts bleeding at all then he will have to put more pressure on there again".

DISCUSSION

Keeping exotic pets at home has become more popular. Therefore, clinical triage centers will have to manage more calls of this nature in the future and be able to provide best evidence-based interim self-care advice for the public calling for assistance.

A search of the current literature confirmed the advice with regards to HWI given by the RN to be current best practice. Atkinson et al1 indicated that HWI is a widely used and accepted treatment for fish-spine stings, although there have not been any randomized controlled trials (RCTs) to date.

Clark et al2 retrospectively reviewed stingray sting cases which attended their ED in San Diego over an 8 year period and concluded that 88% of cases seen in the acute presentation group (within 24 hours of the sting) and treated with HWI had complete relief of pain within 30 min without any administration of analgesia.

There is only a single recorded case of significant thermal burn from over 200 cases of the use of HWI.¹ This treatment modality appears to be safe when used sensibly. "… it need to be quite hot, but not hot enough to burn."

Another important aspect the protocol addresses is the significance to prompt the RN to alert the patient to observe for signs of infection at the site. Clark et al² demonstrated a significant number of patients returning to the ED with wound infections when prophylactic antibiotics were not given at initial presentation. No wonder a group of stingrays is commonly referred to as a 'fever' of stingrays!

REFERENCES

1. Atkinson PRT, Boyle A, Hartin D, McAuley D, (2006) Is hot water immersion an effective treatment for marine envenomation? J Emerg. Med 2006 Jul: 23(7): 503–508.
2. Clark RF, Girard RH, Rao D, Ly BT, Davis DP, (2007) Stingray envenomation: a retrospective review of clinical presentation and treatment in 119 cases. J Emerg. Med 2007 Jul; 33(1):33-7.