Low-voltage electrical injuries and the electrocardiogram: is a 'normal' electrocardiogram sufficient for safe discharge from care? A systematic review.

Introduction: The current Joint Royal Colleges Ambulance Liaison Committee guidelines in the United Kingdom provide clear national guidance for low-voltage electrical injury patients. While patients can be considered safe to discharge with an apparently 'normal' initial electrocardiogram (ECG), some evidence questions the safety profile of these patients with a risk of a 'delayed arrhythmia'. This review aims to examine this as well as identifying the frequency and common arrhythmias that require patients to be conveyed to hospital for further monitoring post electrical injury. It will also aim to improve the understanding of potentially clinically significant arrhythmias that may require clinical intervention or even admission within an in-hospital environment.

Methods: A systematic review using three electronic databases (CINAHL, MEDLINE, AMED) was conducted in January 2022. A preferred reporting items for systematic reviews and meta-analyses (PRISMA) approach was used to identify relevant studies with a suitable quality to support a critical review of the topic. A modified Critical Appraisal Skills Programme quality assessment checklist was used across suitable studies and a descriptive statistics approach was adopted to present the findings.

Results: Seven studies, largely retrospective reviews, met the inclusion criteria. The findings showed 26% of patients had an arrhythmia on initial presentation (n = 364/1234) with incidences of sinus tachycardia, sinus bradycardia and premature ventricular contractions. However, making definitive statements is challenging due to the lack of access to individual patients' past ECGs. Within these arrhythmias' ST segment changes, atrial fibrillation and long QT syndrome could be considered potentially significant, however associated prognosis with these and electrical injuries is unknown. Only six (0.5%) patients required treatment by drug therapy, and a further three died from associated complications. Most patients with a normal ECG were discharged immediately with only a limited follow-up. No presentation of a 'delayed arrhythmia' was identified throughout the studies.

Conclusion: The data for low-voltage electrical injuries are limited, but the potential arrhythmias for this patient group seldom require intervention. The entity of the 'delayed arrhythmia' may not be a reason to admit or monitor patients for prolonged periods. Further studies should consider the safety profile of discharging a patient with a normal ECG.