How Accurate is the Prehospital Diagnosis of Hyperventilation Syndrome?

Background: The literature suggests that hyperventilation syndrome (HVS) should be diagnosed and treated prehospitally. Aim: To determine diagnostic accuracy of HVS by paramedics and emergency medical technicians using hospital doctors' diagnosis as the reference standard. Methods: A retrospective audit was carried out of routine data using linked prehospital and in-hospital patient records of adult patients (≥18 years) transported via emergency ambulance to two emergency departments in the UK from 1 January 2012–31 December 2013. Accuracy was measured using sensitivity, specificity, positive and negative predictive values (NPV/PPVs) and likelihood ratios (LRs) with 95% confidence intervals. Results: A total of 19 386 records were included in the analysis. Prehospital clinicians had a sensitivity of 88% (95% CI [82–92%]) and a specificity of 99% (95% CI [99–99%]) for diagnosing HVS, with PPV 0.42 (0.37, 0.47), NPV 1.00 (1.00, 1.00), LR+ 75.2 (65.3, 86.5) and LR− 0.12 (0.08, 0.18). Conclusions: Paramedics and emergency medical technicians are able to diagnose HVS prehospitally with almost perfect specificity and good sensitivity.