Mortality and risk of cardiac complications among immediate survivors of accidental electric shock: a Danish nationwide cohort study

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.

Acute myocardial damage after electrical injury assessed by MRI

Electrical injuries are not uncommon, and electrical shock-induced cardiac damage can be life-threatening. We present the case of a young patient who suffered from acute myocardial damage due to an occupational electric shock. Myocardial damage was assessed by very early (day 4) and repeated (up to month 18) MRI. Clinical management and patient risk estimation in such a setting are challenging because data on similar non-lethal cases and practice recommendations are scarce in the literature.

Low-voltage electrical accidents, immediate reactions and acute health care associated with self-reported general health 4 years later

BACKGROUND AND AIMS

Electricians frequently experience low-voltage electrical accidents. Some such accidents involve long-term negative health consequences. Early identification of victims at risk for long-term injury may improve acute medical treatment and long-term follow-up. This study aimed to determine acute exposure, health effects and treatment associated with general health ≥ 2 years after low-voltage electrical accidents.

METHODS

In a cross-sectional study, 89 male electricians who had experienced an electrical accident between 1994 and 2001 participated in a 2003 follow-up health examination. They were identified from a registry of low-voltage electrical accidents and included in the study. Based on exposure descriptions in the original accident reports, they were stratified into the following three groups: a current arc accident group (N = 34, mean age 38.8 years [standard deviation, SD = 12.2, range = 21-59]) and two groups with the passage of current through the body, either fixed to the current source ("no-let-go" group; N = 35, mean age 34.0 years [SD = 10.5, range = 21-57]) or not ("let-go" group; N = 20, mean age = 38.7 years [SD = 10.3, range = 21-63]). They retrospectively described acute reactions and assessed their current general health at the health examination. Multivariate linear regression, ordinal logistic regression and Fisher's exact test were used to compare acute reactions with health at follow-up in each exposure group.

RESULTS

The multivariate analysis indicated that after accidents with the passage of current through the body, severe acute headache (β = - 0.56, p = 0.013), years since the accident (β = - 0.16, p = 0.017) and the accident being perceived as frightening (β = - 0.48, p = 0.040) were negatively associated with general health ≥ 2 years later (R² = 0.25, p = 0.002). If the exposure included a no-let-go experience, then acute severe body numbness (β = - 0.53, p = 0.029) was also negatively associated with general health (R² = 0.38, p = 0.002). Without such experience, only acute confusion (β = - 0.90, p = 0.029) was negatively associated with the health at follow-up (R² = 0.24, p = 0.029). In univariate analyses, after the passage of current through the body, acute dizziness (p = 0.029), apathy (p = 0.028), confusion (p = 0.007) and irregular heartbeat (p ≤ 0.05) were associated with poor long-term general health. The no-let-go group, more often than the let-go group, reported panic (p = 0.001), fear of death (p = 0.029), confusion (p = 0.014), exhaustion (p = 0.009), bodily numbness (p = 0.013) and immediate unconsciousness (p = 0.019). Acute symptoms beyond the first day after a current arc accident were associated with poor long-term general health (p = 0.015).

DISCUSSION AND CONCLUSIONS

The acute reactions negatively associated with general health ≥ 2 years after low-voltage electrical accidents should alert the clinician in the acute phase after an electrical accident to the risk of developing negative long-term health effects. Future studies should specify long-term health beyond the concept of general health.

Neurological symptoms and disorders following electrical injury: A register-based matched cohort study

Introduction

Electric shocks may have neurological consequences for the victims. Although the literature on the neurological consequences of electric shocks is limited by retrospective designs, case studies and studies of selected patient groups, previous research provides some evidence of a link between electric shocks, and diseases and symptoms of the central nervous system (CNS)(e.g. epilepsy, migraine and vertigo) and the peripheral nervous system (PNS)(e.g. loss of sensation, neuropathy and muscle weakness). This study aims to employ a register-based, matched cohort study, to investigate whether individuals demonstrate a greater risk of neurological diseases and symptoms of the CNS or PNS in the years following an electrical injury.

Materials and methods

We identified 14,112 electrical injuries over a period of 19 years in two Danish registries, and matched these with three different groups of persons in a prospective matched cohort study: (1) patients with dislocation/sprain injuries, (2) patients with eye injuries and (3) persons employed in the same occupation. Year of injury, sex and age were used as matching variables. The outcomes we identified comprised neurological disorders and central or peripheral nervous system symptoms that covered a range of diagnoses in the Danish National Patient Register. The associations were analysed using conditional logistic regression for a range of time periods (six months to five years) and conditional Cox regression for analyses of the complete follow-up period (up to 20 years).

Results

For victims of electric shock, the CNS sequelae we identified included an increased risk of epilepsy, convulsions, abnormal involuntary movements, headache, migraine and vertigo. We also identified an uncertain, increased risk of spinal muscular atrophy and dystonia, whereas we identified no increased risk of Parkinson’s disease, essential tremor, multiple sclerosis or other degenerative diseases of the nervous system. For victims of electric shock, the PNS sequelae we identified included an increased risk of disturbances of skin sensation, mononeuropathy in the arm or leg and nerve root and plexus disorders. We also identified an uncertain, increased risk of facial nerve disorders, other mononeuropathy, and polyneuropathy.

Conclusion

Our results confirm that electrical injuries increase the risk of several neurological diseases and symptoms of the CNS or PNS in the years following the injury. Most often the diseases and symptoms are diagnosed within the first six months of the injury, but delayed onset of up to 5 years cannot be ruled out for some symptoms and diagnoses. Some of the conditions were rare in our population, which limited our ability to identify associations, and this warrants cautious interpretation. Therefore, further studies are needed to confirm our findings, as are studies that examine the mechanisms underlying these associations.

Unspecified pain and other soft tissue disorders following electrical injuries: a register-based matched cohort study

Objective

This study investigates whether individuals who have sustained an electrical injury (EI) are diagnosed with unspecified pain or pain related to the musculoskeletal system in the years following the injury.

Methods

Individuals listed in Danish registers as having sustained EIs were matched for sex, age, and year of injury in a cohort study with individuals having experienced dislocations/sprains (match 1), eye injuries (match 2), and a sample of individuals with the same occupation without a history of electrical injuries (match 3). Outcomes were unspecified pain and unspecified soft tissue disorders. Conditional logistic regression and conditional Cox regression were applied.

Results

We identified 14,112 individuals who sustained EIs. A higher risk of both outcomes was observed for all three matches, and was highest at the 6- and 12-month follow-ups. The risk of both outcomes was considerably higher for match 3.

Conclusions

This study confirms that exposure to EIs increases the risk of being diagnosed with unspecified pain or unspecified soft tissue disorders both at short and long terms. Our results also showed that the risk of unspecified pain as sequelae is related to the severity of the injury.

Use of troponin assay after electrical injuries: a 15-year multicentre retrospective cohort in emergency departments

Background

Patients with electrical injury are considered to be at risk of cardiac arrhythmia. Assessing the risk of developing a major adverse cardiac event (MACE) is the cornerstone of patient management. The aim of this study was to assess the performance of initial troponin and troponin rise to predict Major Adverse Cardiac Events (MACEs) in all patients with electrical injuries admitted to the Emergency Department.

Methods

This is a multicentre retrospective study in which consecutive patients with electrical injuries admitted to the Emergency Departments (ED) (adult and paediatric) of five French Hospitals were included between 2005 and 2019. The threshold for troponin elevation is based on the European Society of Cardiology guidelines for patients presenting without persistent ST segment elevation. The primary endpoint was the rate of MACE.

Results

A total of 785 included patients were admitted to ED with a first diagnosis of electrical injury during the study period. Troponin assays were performed in 533 patients (67.9%), including 465 of 663 adults (70.1%) and 68 of 122 children (55.7%) and 17/533 (3.2%) of patients had an initial elevated troponin. If none of the clinical criteria for MACE were present (i.e., previous known heart disease, exposure to a high voltage of ≥ 1000 Volts, initial loss of consciousness, or an abnormal initial ECG), this defined a low-risk subgroup (n = 573, 76.0%) that could be safely discharged. The initial positive troponin assay had a sensitivity of 83.3 (95% CI 35.9–99.6%), a specificity of 97.7 (95% CI 96.1–98.8%), a positive likelihood ratio 36.6 (95% CI 18.8–71.1%) and a negative predictive value of 99.9 (95% CI 99.2–99.9%) in predicting a MACE.

Conclusions

Troponin assay appears to be a predictive marker of MACE risk and should be considered in high-risk patients.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13049-021-00955-6.

ECG monitoring in high voltage electric injury patients presenting with normal ECG: Time to revisit practice?

Advanced Trauma Life Support (ATLS) recommends prolonged ECG monitoring of patients with high risk factors post electric injuries, for detecting and treating potentially life threatening arrhythmias. We hereby present our experience of high voltage electric injuries (HVEI) patients with high risk factors, managed at a level 1 Trauma Centre. Seven patients of high voltage electric injuries with significant burns (BSA > 10% of 2nd degree and above) were admitted over a year (Jan 1, 2019 to Dec 31, 2019), age ranging from 11 to 51 (median 25 yrs). Six out of seven patients (85.7%) were males. Mode of injury was recreational in one, workplace related in one and accidental in five (71.4%). Six patients had entry wounds in extremities, and three underwent emergency limb saving surgery (all escharotomies). Three patients underwent eventual amputation of injured extremity. Serum creatine kinase was monitored in all and multisystem involvement was seen in three patients; one patient (referred) required haemodialysis due to renal failure. There was no mortality. In all cases, 24 h continuous ECG monitoring was carried out as per ATLS and ERC (European Resuscitation Council) guidelines. There was no episode of paroxysmal or persistent rhythm disturbance in our patients during in-hospital stay or follow up. Review of pertinent literature suggests similar experiences of other authors. HVEI is a rare injury and most centres have reported on their experience with small number of patients as in our study. Currently, continuous ECG monitoring post HVEI seems to be the safe practice for patients with cardiac co-morbidities. Further studies are required to find other subsets of HVEI patients likely to benefit from ECG monitoring, and the clinical significance of 'delayed arrhythmias' post HVEI.

Patient outcomes after electrical injury - a retrospective study

INTRODUCTION

People exposed to electrical injuries are often admitted to hospital for observation. Current evidence suggests that patients who have a normal ECG on admission after a low-voltage injury, with no loss of consciousness or initial cardiac arrest may be discharged home after a short observation time. Currently, there are no established standards for the duration of monitoring after electric shock, but 24 h of observation is the most commonly adopted approach. We carried out a retrospective study of patients admitted after electrical injuries to determine the in-hospital outcomes and 30-day mortality in these patients.

METHODS

We performed a chart review of all patients with electrical injuries admitted to Østfold Hospital, Norway between the years 2001 and 2019, to determine in-hospital and 30-day mortality and the frequency of various cardiac and non-cardiac complications.

RESULTS

Mean age of 465 included patients (88% males) was 31 years. Of all injuries, 329 (71%) were work-related, 17 (3.7%) involved loss of consciousness. Furthermore, 29/437 (6.6%) were high voltage (> 1000 V), and 243/401 (60.6%) were transthoracic injuries. 369 (79.4%) were discharged same day. None of the admitted patients died in hospital nor did any die within 30 days of admission, yielding a 30-day mortality of 0% (95% CI 0-0.8). At admission troponin was elevated in three (0.6%) patients, creatinine kinase (CK) in 30 (6.5%) and creatinine in six (1.3%). Electrocardiogram (ECG) abnormalities were described in 85 (18%) patients. No serious arrhythmias were detected. When comparing high- vs low-voltage or transthoracic vs other injuries, there were no significant differences between most of the outcomes, except for more ECG abnormalities in the transthoracic group, whereas more patients had elevated CK, and fewer discharged the same day in high-voltage injuries.

CONCLUSION

No in-hospital nor 30-day mortality or serious arrhythmias were encountered in those who were assessed, regardless of the type of injury. Troponin and creatinine were rarely elevated. It seems that conscious patients admitted with a normal ECG following a low-voltage injury may safely be discharged home after a quick clinical assessment including ECG.

Mental disorders following electrical injuries-A register-based, matched cohort study

Introduction

Electrical injuries happen every day in homes and workplaces. Not only may these injuries cause physical damage and disability, they may also cause mental disorders. The aim of this study was to investigate if persons with an electrical injury suffer from mental disorders in the following years.

Material and methods

In a prospective matched cohort design, we identified 14.112 electrical injuries in two Danish registries and matched these with persons with dislocation/sprain injuries or eye injuries, respectively, as well as with persons from the workforce from the same occupation, using year of injury, sex and age as matching variables. We identified possible outcomes in terms of mental diagnoses in the Danish National Patient registry, based on literature, including reviews, original studies and case-reports as well as experiences from clinical praxis. The associations were analyzed using conditional cox- and logistic regression.

Results

We found that the following of the examined outcomes were associated with exposure to an electrical injury compared to the matched controls. Some of the outcomes showed the strongest associations shortly after the injury, namely ‘mental disorders due to known physiological condition’, ‘anxiety and adjustment disorders’, and especially the ‘Post Traumatic Stress Disorder (PTSD)’ subgroup. The same pattern was seen for ‘Depression’ although the associations were weaker. Other conditions took time to develop (‘Somatoform disorders’), or were only present in the time to event analysis (‘other non-psychotic mental disorders’ and ‘sleep disorders’). The findings were consistent in all three matches, with the highest risk estimates in the occupation match.

Conclusion

Electrical injuries may result in mental disorders, both acute and several years after. However, the absolute risk is limited as most of the outcomes are rare.

Contacts with general practitioner, sick leave and work participation after electrical injuries: a register-based, matched cohort study

OBJECTIVE

Exposure to electrical current may cause injury with both mental and physiological consequences. This may lead to increased contacts with general practitioners (GP) and the injured person may develop reduced ability to work. We aimed to examine these outcomes in terms of work-participation, long-term sick leave and contacts with GPs.

METHODS

In a matched cohort design, we identified 14 112 electrical injuries in two registries and matched these with both patients with distorsion injuries or eye injuries, and with persons from the same occupation, using year of injury, sex and age for matching. We defined the outcomes based on register information regarding contacts with GPs and public transfer income. After the injury, we determined if the person had a long-term sick leave episode during the first 6, 12 months and 5 years. We calculated work participation during the year and 5 years and the number of GP contacts in the year of the injury, the year after and 5 years after the injury and dichotomised this at twice the mean number of contacts in the study population. The associations were analysed using conditional logistic regression.

RESULTS

We found increased risk for all defined outcomes, with the highest estimates in the occupation match. The risk estimates were similar over time. Adjusting for previous work participation increased the estimates slightly, whereas adjusting for previous contacts with GPs reduced the estimates. Restricting to those with at longer hospitalisation increased the estimates.

CONCLUSION

Electrical injuries increase risk of long-term sick leave, low work participation and increased contacts with GPs.

Electrical Burns During Fruit Harvesting

Electrocutions during tree trimming or fruit harvesting are occasionally reported in the public media, but the actual incidence is unknown. Some fruit trees (eg, mango and avocado) can exceed 30 feet, with dense foliage concealing the fruit and overlying power lines so burns associated with harvesting these fruits are often exacerbated with falls. However, there are limited data on this subject. To fill this gap, we provide some of the first information on this unique injury pattern. All electrocutions from 2013 to 2018 were retrospectively reviewed at an ABA-verified burn center. Demographics, injury patterns, and complications were analyzed. Of 97 electrocutions, 22 (23%) were associated with fruit procurement. This population was aged 43 ± 14 years, 95% (n = 21) male, injury severity score of 15 ± 13, and total body surface area burned 4% [1%-9%]. Third-degree burns were present in 36% (n = 8). ICU admission was required in 59% (n = 13) and 39% of the survivors required operative interventions for the burn. Compartment syndrome occurred in 18% (n = 4) and 14% (n = 3) patients required amputations. Falls complicated the care in 50% (n = 11), with associated head, chest, and/or extremity trauma. Mortality was 32% (n = 7), with three patients presenting dead on arrival. All but 3 injuries occurred between June and December, coinciding with mango and avocado season. Electrocution during fruit picking is a seasonal injury often exacerbated by falls. Management is challenging, and favorable outcome depends on recognition of the complexity of the polytrauma.

Direct current electrical injuries: A systematic review of case reports and case series

BACKGROUND

Direct current (DC) powered equipment and devices, including photovoltaic systems, high-voltage direct current power lines and novel concepts in electromobility have become increasingly popular in recent years. However, under adverse circumstances by malfunction or mishandling of these applications electrical injuries may occur when electric current passes through the human body. This review aimed at systematically summarizing the medical consequences of DC electrical injuries described in case reports and case series.

METHODS

The Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guided the methodological conduct and reporting.

RESULTS

Sixteen case reports and 3 case series were eligible for this review and included 70 patients. The reviewed articles were very heterogeneous regarding sources of DC electrical injuries and the reported medical consequences, including burns and skin lesions (n=67), neurological consequences (n=11), unconsciousness (n=10), cardiac consequences (n=8) and bone fractures (n=6). Seventeen individuals did not survive the electrical injuries.

CONCLUSION

From the few available data and partly incomplete documentations of cases we could gather hints of DC medical consequences, however, it was not possible to identify well-defined medical consequences for various circumstances of DC electrical injuries in occupational and non-occupational settings. To achieve this goal, additional studies are required, each providing a comprehensive description of the medical consequences and the circumstances of the electrical injuries.

Risk of cardiac arrhythmias after electrical accident: a single-center study of 480 patients

Objective

Patients with electrical injury are considered to be at high risk of cardiac arrhythmias. Due to the small number of studies, there is no widely accepted guideline regarding the risk assessment and management of arrhythmic complications after electrical accident (EA). Our retrospective observational study was designed to determine the prevalence of ECG abnormalities and cardiac arrhythmias after EA, to evaluate the predictive value of cardiac biomarkers for this condition and to assess in-hospital and 30-day mortality.

Methods

Consecutive patients presenting after EA at the emergency department of our institution between 2011 and 2016 were involved in the current analysis. ECG abnormalities and arrhythmias were analyzed at admission and during ECG monitoring. Levels of cardiac troponin I, CK and CK-MB were also collected. In-hospital and 30-day mortality data were obtained from hospital records and from the national insurance database.

Results

Of the 480 patients included, 184 (38.3%) had suffered a workplace accident. The majority of patients (96.2%) had incurred a low-voltage injury (< 1000 V). One hundred and four (21.7%) patients had a transthoracic electrical injury while 13 (2.7%) patients reported loss of consciousness. The most frequent ECG disorders at admission were sinus bradycardia (< 60 bpm, n = 50, 10.4%) and sinus tachycardia (> 100 bpm, n = 21, 4.4%). Other detected arrhythmias were as follows: newly diagnosed atrial fibrillation (n = 1); frequent multifocal atrial premature complexes (n = 1); sinus arrest with atrial escape rhythm (n = 2); ventricular fibrillation terminated out of hospital (n = 1); ventricular bigeminy (n = 1); and repetitive nonsustained ventricular tachycardia (n = 1). ECG monitoring was performed in 182 (37.9%) patients for 12.7 ± 7.1 h at the ED. Except for one case with regular supraventricular tachycardia terminated via vagal maneuver and one other case with paroxysmal atrial fibrillation, no clinically relevant arrhythmias were detected during the ECG monitoring. Cardiac troponin I was measured in 354 (73.8%) cases at 4.6 ± 4.3 h after the EA and was significantly elevated only in one resuscitated patient. CK elevation was frequent, but CK-MB was under 5% in all patients. Both in-hospital and 30-day mortality were 0%.

Conclusions

Most of cardiac arrhythmias in patients presenting after EA can be diagnosed by an ECG on admission, thus routine ECG monitoring appears to be unnecessary. In our patient cohort cardiac troponin I and CK-MB were not useful in risk assessment after EA. Late-onset malignant arrhythmias were not observed.

Electrical injury - a dual center analysis of patient characteristics, therapeutic specifics and outcome predictors

BACKGROUND

Electrical injuries represent life-threatening emergencies. Evidence on differences between high (HVI) and low voltage injuries (LVI) regarding characteristics at presentation, rhabdomyolysis markers, surgical and intensive burn care and outcomes is scarce.

METHODS

Consecutive patients admitted to two burn centers for electrical injuries over an 18-year period (1998-2015) were evaluated. Analysis included comparisons of HVI vs. LVI regarding demographic data, diagnostic and treatment specific variables, particularly serum creatinine kinase (CK) and myoglobin levels over the course of 4 post injury days (PID), and outcomes.

RESULTS

Of 4075 patients, 162 patients (3.9%) with electrical injury were analyzed. A total of 82 patients (50.6%) were observed with HVI. These patients were younger, had considerably higher morbidity and mortality, and required more extensive burn surgery and more complex burn intensive care than patients with LVI. Admission CK and myoglobin levels correlated significantly with HVI, burn size, ventilator days, surgical interventions, amputation, flap surgery, renal replacement therapy, sepsis, and mortality. The highest serum levels were observed at PID 1 (myoglobin) and PID 2 (CK). In 23 patients (14.2%), cardiac arrhythmias were observed; only 4 of these arrhythmias occurred after hospital admission. The independent predictors of mortality were ventilator days (OR 1.27, 95% CI 1.06-1.51, p = 0.009), number of surgical interventions (OR 0.47, 95% CI 0.27-0.834, p = 0.010) and limb amputations (OR 14.26, 95% CI 1.26-162.1, p = 0.032).

CONCLUSIONS

Patients with electrical injuries, HVI in particular, are at high risk for severe complications. Due to the need for highly specialized surgery and intensive care, treatment should be reserved to burn units. Serum myoglobin and CK levels reflect the severity of injury and may predict a more complex clinical course. Routine cardiac monitoring > 24 h post injury does not seem to be necessary.