• How accurate is the prehospital diagnosis of hyperventilation syndrome?

      Wilson, Caitlin; Harley, Clare; Steels, Stephanie (2020-11-09)
      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. Abstract published with permission.
    • Hyperventilation syndrome: diagnosis and reassurance

      Wilson, Caitlin (2018-09)
      Abstract published with permission. This article provides an overview of hyperventilation syndrome (HVS). Hyperventilation is to breathe in excess of metabolic requirements; in the absence of an underlying organic cause, it is defined as HVS. Alternative terms used in literature are panic or anxiety attack, panic or anxiety disorder, dysfunctional breathing and breathing pattern disorder. This article explores HVS signs and symptoms beyond the familiar clinical signposts of tachypnoea, chest tightness, paraesthesia and anxiety. It will also discuss differential diagnoses and pre-hospital treatment of HVS, focusing on reassuring patients and assisting them in establishing a good respiratory pattern. Patients with HVS use a significant amount of hospital and emergency service resources, ideally placing paramedics to diagnose and treat HVS in the pre-hospital setting to avoid unnecessary and costly hospital admissions. Further research is needed to evaluate the pre-hospital prevalence and diagnostic accuracy of HVS, identify clear diagnostic criteria and design screening tools.
    • Pre-hospital diagnostic accuracy for hyperventilation syndrome

      Wilson, Caitlin; Harley, Clare; Steels, Stephanie (2017-10)
      Background Hyperventilation syndrome (HVS) encompasses a wide variety of symptoms and is diagnosed by excluding organic causes for patients’ symptoms. Literature suggests that HVS should be diagnosed and treated pre-hospitally to avoid costly attendances at Accident and Emergency departments. The study aim was to determine diagnostic accuracy for HVS of paramedics and emergency medical technicians (index test) in comparison to hospital doctors (reference standard). Methods A retrospective cross-sectional audit of routine data utilising linked pre-hospital and in-hospital patient records of adult patients (age ≥18 years) transported via emergency ambulance to two Accident and Emergency departments in the United Kingdom from January 2012 – December 2013. Agreement between pre-hospital and in-hospital HVS diagnoses was calculated using percent agreement, Cohen’s kappa and prevalence-adjusted bias-adjusted kappa. Accuracy was measured using sensitivity, specificity, predictive values and likelihood ratios with 95% confidence intervals. Results A total of 19 386 records were included in the analysis. Percent agreement between pre-hospital clinicians and hospital doctors was 98.73%, producing kappa of κ=0.57 and adjusted kappa of PABAK=0.97. Pre-hospital clinicians had a sensitivity 0.88 (0.82, 0.92) and specificity 0.99 (0.99, 0.99) 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). Subgroup analyses for sensitivity were statistically non-significant but for positive predictive values were statistically significant (p<0.001) for the number of pre-hospital diagnoses and patient age. Conclusions Paramedics and emergency medical technicians were able to diagnose HVS pre-hospitally with almost perfect specificity and good sensitivity. Pre-hospital diagnostic accuracy was highest for patients less than 30 years of age and if HVS was the sole diagnosis documented. Following this study, a review of the local ambulance service policy excluding adult HVS patients from referrals to Primary Care Services is anticipated. https://emj.bmj.com/content/34/10/e3.3 This is an Open Access article distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/ http://dx.doi.org/10.1136/emermed-2017-207114.9