Tracey Barron

Academic Research

By Tracey Barron

A study published almost five years ago (Sept/Oct 2008) in Prehospital Disaster Medicine (PDM) looked at the potential of Protocol 6: Breathing Problems for distinguishing between minor or non-critical conditions from conditions posing greater risk to the patient and, consequently, determining the appropriate level of care required on scene and, if necessary, during transport.1

Considering Protocol 6 was among the most commonly used protocols at the time in the communication center, it only makes sense that this protocol is also among the most scrutinized in the Medical Priority Dispatch System (MPDS).

The study from 2008 relied on data gathered between September 2005 and August 2006 from the London Ambulance Service (LAS), National Health Service Trust, U.K., while the most recent study expanding on previous research relied on data gathered from an Academy-certified Accredited Center of Excellence (ACE); the study was published in the same magazine in August 2012.

Results from the 2008 study concluded that the interrogation associated with MPDS Protocol 6 did demonstrate the protocol’s significance in EMD selection of the response code for the breathing problem identified, although it did not—nor was it an objective—narrow the selection by isolating contributing factors, such as age or the patient’s coexisting conditions, in prioritizing the response mode.

While the MPDS provides a rich mix of severe outcomes in the higher priority levels based on reported signs and/or symptoms, the authors recommended further research that would help in the classification of patient subgroups correlated to the patients’ other medical conditions; the existing conditions could be related to the reason for the call to 9-1-1.

In the case of breathing problems, rapid subgroup identification could result in an immediate upgrade to the response mode due to the cardiac arrest potential of patients within these subgroups experiencing severe respiratory distress.

The subsequent study looking at breathing problems (PDM, August 2012) examined combinations of Key Questions (KQ) in MPDS Protocol 6 to discover optimal KQ combinations for immediate identification of potential cardiac arrests in calls involving breathing problems.

Data analyzed for the retrospective study was collected over an 11-month period. Forty-two thousand cases were recorded, of which the patients were almost evenly split between female and male (52% were female and 48% were male), and the median age was 61.

Among the key findings was the significantly higher potential of cardiac arrest in asthmatic (KQ 5) patients with the following conditions precipitating the call: the patient was not alert (KQ 1) and, also, having difficulty speaking between breaths (DSBB) (KQ 2); the patient was not alert (KQ 1), having DSBB (KQ 2), and changing color (KQ 3); and, finally, the patient was not alert (KQ 1), having DSBB (KQ 2), and felt clammy to the touch (KQ 4).

These cases would require the higher priority response coding.

In comparison, a patient with asthma experiencing abnormal breathing but without the other signs and/or symptoms was not as likely to suffer a cardiac arrest.

In conclusion, a prioritization scheme accounting for the presence of either single or multiple signs and/or symptom combinations for Protocol 6: Breathing Problems helps to better define DELTA-level cases in the MPDS.

What does this mean to you and your communication center?

An EMD should listen for the presence of signs and/or symptoms that could indicate higher levels of response compared to response based on a single answer.

Finally, research provides the evolution necessary to MPDS relevance in the dispatch community. In this case, combining KQs could be the next step behind the logic of ProQA. Results could increase an EMD’s ability to send the most appropriate response for calls involving breathing problems and further the optimum use of our limited emergency response systems.

Future research will build on these past studies using different sets of data and a methodology dependent on the study’s objective. And that’s what I call the joy of research. We are never exactly sure where research will take us and every project gives others the opportunity to view the subject from a new perspective.


1 Clawson, J., Olola C., Heward A., Patterson B., Scott G. Profile of Emergency Medical Dispatch Calls for Breathing Problems within the Medical Priority Dispatch System Protocol. Prehosp Disaster Med. 2008 Sep-Oct;23(5):412-9. (accessed Dec. 26, 2012).

2 Clawson, J., Barron, T., Scott, G., Siriwardena, A., Patterson, B., and Olola C., Medical Priority Dispatch System Breathing Problems Protocol Key Question Combinations are Associated with Patient Acuity, Prehosp Disaster Med. 2012 Aug;27(4)375-80. DOI: (accessed Dec. 26, 2012).