Point-of-care ultrasound for FAST and AAA in rural New Zealand: Quality and impact on patient care

Abstract

Introduction: Point-of-care ultrasound (POCUS) has the potential to improve access to diagnostic imaging for rural communities. This article evaluates the sensitivity and specificity, impact on patient care, quality and safety of two common POCUS examinations - focused assessment with sonography in trauma (FAST) and aortic aneurysm (AAA) - in the rural context. Methods: This study is a subgroup analysis of a larger study into POCUS in rural New Zealand. Twenty-eight physicians in six New Zealand rural hospitals, with limited access to formal diagnostic imaging, completed a questionnaire before and after POCUS scans to assess the extent to which it altered diagnostic certainty and patient disposition (discharge v admission to rural hospital v transfer to urban hospital). The investigators and a specialist panel reviewed images for technical quality and accuracy of interpretation, and patient clinical records, to determine accuracy of the POCUS findings and their impact on patient care. Results: For FAST and AAA scans respectively, sensitivities were 75% and 100%, and specificities 100% and 93%; rural doctors correctly interpreted their POCUS images for 97% and 91% of scans. The proportions of scans that had either a 'significant' or 'major' impact on patient care were 17% and 31%. POCUS resulted in the disposition being de-escalated for 15% and 10% of patients and escalated for 5% and 3% of patients. Conclusions: In the rural context, POCUS AAA is a reliable 'rule out' test for ruptured abdominal aortic aneurysm and FAST scan has a role as a 'rule in' test for solid organ injury. These findings are consistent with larger studies in the emergency medicine literature.