Profile of Emergency Medical Dispatch Calls for Breathing Problems within the Medical Priority Dispatch System Protocol

Introduction: A common chief complaint to emergency dispatch communication centers worldwide is "breathing problems". The chief complaint of breathing problems represents a wide spectrum of underlying diseases, patient conditions, and onset types. The current debate is on the potential ability of a dispatch protocol to safely and with high specificity, differentiate patients with minor or non-critical conditions from those conditions that pose risk to the patient and require advanced life support evaluation and care. This issue also has extended into the paramedic prehospital evaluation realm. Objective: The objective of this study was to describe the distribution of Medical Priority Dispatch System (MPDS) codes representing the spectrum of clinical descriptions within the breathing problems chief complaint and their associated outcomes, at the scene and during transport, as determined by [UK] paramedics. Methods: A retrospective, one-year study (September 2005 to August 2006) of a de-identified aggregate dataset from the London Ambulance Service (LAS) Trust was evaluated. A profile of the distribution of calls, incidents, patients, and outcomes (cardiac arrest [CA] and blue-in [BI] high acuity i.e., patients transported with lights and siren based on paramedic protocol) for the breathing-problems chief complaint was evaluated. Odds ratios and 95% confidence intervals (CI) were used to quantify associations between the MPDS priority level's concurrent asthmatic conditions and outcomes. Two-sided Fishers exact p-values were obtained to determine statistically significant associations, at a level of 0.05. Results: Sixteen percent (95,848/599,093) of all the patients were classified under the breathing problems chief complaint. Of these 95,848 patients, 367 (0.38%) were CA outcomes, and 7.82% (n = 7,493) were BI outcomes. The Cardiac Arrest Quotient (i.e., the number of CA cases as a percentage of the number of patients) for the ECHO priority level was 46 times higher than was that of non-ECHO priority levels: DELTA and CHARLIE (17.05% vs. 0.37%). Asthmatics were associated with CA outcome (OR(95% CI): 0.60(0.47,0.77), p < 0.001), but not with BI outcome. Conclusions: The MPDS coding yielded a richer mix of severe outcomes in the higher priority levels. The Severe Respiratory Distress coding had the greatest number of patients and severe outcomes. Future studies that help refine the Severe Respiratory Distress code in the MPDS by more specific subgroups of patients would be beneficial.