INTRODUCTION

Addison's disease is a rare, chronic condition brought on by failure of the adrenal glands, affecting people of all ages. It affects the production of cortisol and aldosterone, both essential in the body's functioning. A very low level of cortisol can be life threatening, since cortisol regulates blood pressure and the immune system, balances the effect of insulin, and helps the body respond to stress. Aldosterone helps to control blood pressure and regulate salts in the blood.

Symptoms of this disease usually include a general feeling of being unwell, lethargy and fatigue, weight loss, faintness, and joint and muscle pain. If the condition is left untreated or poorly managed, the patient may experience a life-threatening adrenal crisis. This includes severe dehydration, vomiting, diarrhea, low blood pressure, and extreme muscle weakness.

The Medical Priority Dispatch System (MPDS®) protocol (Priority Dispatch Corp., Salt Lake City, Utah USA) is designed to guide the Emergency Medical Dispatcher (EMD) through a predictable, accurate, repeatable process during an emergency call to EMS. It uses a system of interrogation and symptom determinations that enable the EMD to prioritize system response according to an agency-defined configurations.

Each complete MPDS call results in a determinant code that fits into a "priority level" from OMEGA (the lowest priority) through, ALPHA, BRAVO, CHARLIE, DELTA and ECHO (the highest priority). These levels signify the urgency and relative acuity of the patient. In addition, the MPDS prioritizes the actions of the EMD and bystanders to ensure that life-threatening conditions are identified and responded to immediately.

Management and Outcome

In this particular case, a second party caller (with or near the patient) has called because his wife is having an "Addison's emergency." The following exchange occurs as the EMD politely and efficiently enters the call into ProQA (software version of the MPDS), Chief Complaint 26, "Sick Person (Specific Diagnosis)."

The following is a transcript of the call:

Caller: "My wife is uh…uh…has got Addison's disease and she's been vomiting twice, uh, so she's got, uh, it's an Addison's emergency."

EMD: "Right, okay. One second."

Caller: "I've already tried to give her a 20mg, uh, hydrocortisone, and she's been sick, um, so she's not kept it down, uh, and I'm going to give her, uh, an injection.

EMD: "Right, okay." The EMD verifies the address of the emergency.

EMD: "Are you with the patient now?"

Caller: "Yes I am, yes."

EMD: "How old is she?"

Caller: "Uh, she's 35".

EMD: "She's 35, okay. Is she awake?"

Caller: "Yes she is."

EMD: "Is she breathing?"

Caller: "Yes."

EMD: "Okay. Is she completely alert?"

Caller: "Uh yes, yes she is at the minute."

EMD: "Is she breathing normally?"

Caller: "Um, yes and she was saying she's a little bit wheezy but I think that's just because she's got, um, asthma as well."

EMD: "Oh does she? Okay, and does she have any pain?"

Caller: (To patient) "Do you have any pain?" Patient heard talking quietly in the background.

Caller: "In the right hand lower side of your back, you've got a pain? Yeah."

EMD: "She does yeah?"

Caller: "Well she did. She says it's gone now."

EMD: "Okay, is she bleeding or vomiting blood?"

Caller: "Um, (talks to patient), is it, is it blood? Is there blood in there? No, uh, no I don't, no, there isn't any blood, no." The EMD codes the call as a 26A11 (vomiting).

EMD: "Okay, stay on the line for me one second. Okay, we do have an ambulance driving to you, just stay on the line."

Caller: "Um, am I allowed to go ahead and give her, her hydrocortisone injection? Adrenalin."

EMD: "Do what the Doctor's advised for these situations okay."

Caller: "Alright. Uh, cortisol sorry."

EMD: "I'm organizing help for you now. Stay on the line and I'll tell you exactly what to do next."

Caller: "Okay, um. Okay, so I'll…"

EMD: "Giving the injection now are you?"

Caller: "Uh, I'm just sorting out the, uh, the, the vial (caller talks quietly to himself)." The EMD records the patient's full name and D.O.B, as well as verifying some personal patient information.

EMD: "And you're giving the, you're giving her the injection now are you?"

Caller: "I'm just taking it and drawing up. Just bear with me (caller talks quietly with patient). Shall I wait for them to do it?"

EMD: "There should be someone there. Are you able to go and have a look out your front door?"

The initial response arrives and the EMD ends the call.

A "fast response vehicle" (advance life support (ALS) manned car) was sent and was backed up by a double-manned ALS ambulance. The responding staff administered 100mg hydrocortisone (intramuscular) for the treatment of the adrenal crisis, and 4mg of Ondansetron (intramuscular) for the treatment of nausea and vomiting. They then transported the patient to hospital. The patient's final outcome is unknown.

Discussion: Addison's disease can pose EMDs with a difficult situation. As was the case in this call, the disease is often offered by the caller as a diagnosis during the outset of the call. The EMD may then have to clarify exactly what has happened in order to obtain symptoms they can use to prioritize the patient. To compound the problem, due to the rare nature of the disease, EMDs seldom deal with patients with an Addison's crisis and may be unaware of the seriousness of the situation, particularly as the patient may not present with a priority symptom (as listed in the MPDS).

In this particular case, the initial symptom offered by the caller was that of vomiting, which in and of itself is not necessarily a life threatening symptom and not one that will be prioritized with an immediately life threatening dispatch code or a (locally defined) rapid attendance by EMS. In fact, in the UK, this type of call may be passed to a clinician for further triage. This further triage may be immediate, or it may be subject to a delay before the patient is telephoned back.

The MPDS Chief Complaint 26 "Sick Person (Specific Diagnosis)" is designed to be used for patients with a non-categorizable Chief Complaint, who do not have an identifiable priority symptom. Sometimes the caller/patient has no idea what is wrong, while other times Protocol 26 is selected because the caller describes a specific medical condition that does not fit into any other Chief Complaint. Because of this variability, it is especially important in these cases that the EMD carries out a complete interrogation to obtain symptoms that can be correctly prioritized.

While MPDS Chief Complaint 26 does list some specific clinical conditions such as "Sickle cell crisis" and "Thalassemia", it does not, and cannot, provide an exhaustive list of medical conditions that might be handled on that Chief Complaint. In cases where a caller volunteers an unlisted condition, the EMD should proceed with caution.

The ProQA software has always offered the EMD the ability to "override" and select a higher level of dispatch code than the logic recommended code. EMDs have been given this safety valve as an option when the code appears to be too low to appropriately reflect the severity of the case. An Addison's crisis case provides an example where such an "override" may be appropriate because it allows an EMD to err on the side of caution by assigning a higher level of dispatch.

Another very important point to consider is the caller's response to the question, "Is she breathing normally?" This caller's answer, "Um, yes and she was saying she's a little bit wheezy but I think that's just because she's got, um, asthma as well," which starts with "yes," only suggests that the patient's wheeze might be normal for her. It is essential that an EMD clarifies such an ambiguous statement as it is not definitively clear, especially as wheezing is not a normal state of breathing.

If there is any confusion, or the EMD is in any doubt, this is the time to clarify and confirm exactly what the caller means. The answer to this question is the difference between an ALPHA (often a basic life support response travelling under normal road conditions) and a CHARLIE (often an advance life support response travelling under normal road conditions) level of response. It's not just the skill level or speed of the responding crew that must be considered, but if this call is assigned to the ALPHA level, the patient may experience a prolonged delay in a response being sent due to other higher priority calls taking precedence in a system where resources are limited. It is essential that the interrogation obtains all symptoms and ensures that priority symptoms (such as breathing problems) take precedence.

Making the case even more complex is the issue of the patients' own hydrocortisone medication. When the caller asks if he should administer the medication, the EMD, quite correctly, advises him to do what his doctor has instructed for these situations. Without the patient's full clinical background, and in the absence of any protocol instruction to give a specific medication, the EMD does not have the knowledge or training to advise whether a medication should or should not be given. Advising the caller not to do it could be as detrimental as advising them to do it. By referring the caller back to the advice from their doctor, they allow the caller, who is in a much more informed position in this situation, to make the decision.

The EMD is also tracking the responding vehicle on their computer aided dispatch system. The caller is clearly hesitant to give the injection, but this extra knowledge ensures the EMD can let the caller know as soon as the response is outside his address. In this case, the fortuitous timing of the responders' arrival means the caller can ask for the assistance of the paramedic.

In conclusion, with the exception of those already dealt with by the MDPS, when an EMD is given a specific medical condition that they are unsure or unfamiliar with, they should err on the side of caution when assigning a dispatch code or locally defined response.

REFERENCES

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2. Rolland E, Moore KM, Robinson VA, McGuinness D. Using Ontario's Telehealth health telephone helpline as an early-warning system: a study protocol. BMC Health Serv Res. 2006;6:10.
3. NHS Direct [Internet]. Available from: http://www.nhsdirect.nhs.uk/ About/WhatIsNHS Direct/History [updated 2013; cited 2012 Dec 18].