Background Acute heart failure (AHF) symptoms are similar to some respiratory conditions making it challenging for paramedics to diagnose AHF accurately, especially as they infrequently encounter it. Little is known about the clinical reasoning strategies (CRS) used by student or qualified paramedics to diagnose and manage patients with AHF, inaccurate diagnosis associated with inappropriate diuretic management can cause patient complications.

Research aim To explore CRS student paramedics use during their diagnosis and management of AHF, examining differentiation processes between AHF and a respiratory condition presenting with similar signs and symptoms.

Methodology A convenience sample of ten senior student paramedics from a BSc (Hons) Paramedic Science programme participated in a two phase exploratory study. Phase A involved assessment of three high-fidelity simulations of: (a) AHF; (b) pneumonia; (c) infective exacerbation of chronic obstructive pulmonary disease each patient complaining of breathlessness. Phase B incorporated semi-structured interviews to explore participants' CRS during these simulations. Data analysis used thematic analysis.

Findings and discussion Four key themes emerged: (i) Identification of Heart Failure; (ii) Process of Differentiation; (iii) Sources of Influence; (iv) Management Decisions. Participants demonstrated two forms of CRS; initially backward reasoning, using illness-scripts, rapidly determined need for immediate resuscitation and evaluated the opportunity available to conduct assessment and examination. This involved searching for cues used in forward hypothetical-deductive clinical reasoning; the strategy participants used during diagnosis. Two participants inappropriately activated illness-scripts through cue misinterpretation, resulting in incorrect diagnosis and pharmacological therapy. Participants had a low-threshold of pharmacological treatment instigation, even when the diagnosis was uncertain.

Conclusion Although a small study, consideration should be given to participants immature CRS; they may require post-registration support to develop consistently accurate and appropriate clinical decisions which avoid patient exposure to risk. Further research should identify whether other paramedic students, from the various registration routes, reflect these results.