Christopher J. Andrews

Telephone-mediated lightning injury: An australian survey

Each year in Australia, about 60 people report injuries attributable to lightning surges while using a telephone during nearby thunderstorms. This paper presents information about such incidents and describes a retrospective survey of more than 300 telephone users reporting injuries possibly attributable to lightning. Questionnaires yielded 132 usable responses, and the results were analysed to identify the extent and nature of the lightning injuries. These are compared with direct strike injuries. Three distinct telephone-mediated lightning strike syndromes are identified (statistically) among the victims.

Distribution of lightning injury mechanisms

While many mechanisms of injury have been described, studies of the frequency of each mechanism have not been attempted. This paper will review the mechanisms of injury as well as a likely distribution between the mechanisms of injury and help to dispel the myth that the majority of injuries and deaths are caused by ‘direct’ strikes.

Further Documentation of Remote Effects of Electrical Injuries, With Comments on the Place of Neuropsychological Testing and Functional Scanning

It is not always recognized that morbidity from electrical injury is not confined to effects in the pathway of current flow. Indeed a major element of the disability suffered by victims occur from effects remote to the line of current passage. Recent papers have rightly drawn further attention to this, and it is an active area of controversy and research. This paper documents the authors experience in this area and confirms the recognizable elements of remote injuries which are seen to be generally psychological in nature. The question of mechanisms of causation of these disabilities is raised. This paper then presents summary results of a collation of neuropsychological investigations and functional cerebral scanning in an attempt to correlate the two. It is concluded that it is possible to overlook the remote effects of electrical injury to the detriment of victims

Post electrical or lightning injury syndrome: a proposal for an American Psychiatric Association's Diagnostic and Statistical Manual formulation with implications for treatment

In the past, victims of electrical and lightning injuries have been assessed in a manner lacking a systematic formulation, and against ad hoc criteria, particularly in the area of neuropsychological disability. In this manner patients have, for example, only been partially treated, been poorly or incorrectly diagnosed, and have been denied the full benefit of compensation for their injuries. This paper contains a proposal for diagnostic criteria particularly for the neuropsychological aspects of the post injury syndrome. It pays attention to widely published consistent descriptions of the syndrome, and a new cluster analysis of post electrical injury patients. It formulates a proposal which could be incorporated into future editions of the American Psychiatric Associations Diagnostic and Statistical Manual (DSM). The major neuropsychological consequences include neurocognitive dysfunction, and memory subgroup dysfunction, with ongoing consequences, and sometimes including progressive or delayed psychiatric, cognitive, and/or neurological symptoms. The proposed diagnostic criteria insist on a demonstrated context for the injury, both specifying the shock circumstance, and also physical consequences. It allows for a certain delay in onset of symptoms. It recognizes exclusory conditions. The outcome is a proposal for a DSM classification for the post electrical or lightning injury syndrome. This proposal is considered important for grounding patient treatment, and for further treatment trials. Options for treatment in electrical or lightning injury are summarised, and future trials are foreshadowed.

Neurological and neuropsychological consequences of electrical and lightning shock: review and theories of causation

Injuries from lightning and electrical injuries involve multiple systems of the body, however neurological symptoms are very widely reported. A disabling neuropsychological syndrome is also noted. This paper presents a comprehensive review of neurological and neuropsychological symptoms. Partial theories ofcausation for these injuries have been advanced, however, there is no convincing explanation for both delay in onset of symptoms and also the genesis of the neuropsychological syndrome. A theory of causation is proposed which satisfies both these constraints. This theory suggests circulating hormones such as cortisol, together with nitric oxide and oxidant free radicals from glutamatergic hyper-stimulation, act on tissues remote from the injury path including the hippocampus. This theory opens a research path to explore treatment options.

Transthoracic ventricular fibrillation charge thresholds.

Standards, including IEC 60479-1 and -2, provide current-based ventricular fibrillation thresholds (VFT) for stimuli durations between 0.1 ms and 10 s. It has been established that the amount of electrical charge, not the current calculated by root-mean-square, is most representative of the effects of cardiac stimulation. There are no unified models that present transthoracic charge VFTs for a wide range of stimuli durations. This work proposes a new unified charge model applicable to transthoracic stimuli durations ranging over 1 μs - 300 s. VFTs were compiled from our previous animal work and from other published reports, including from the studies that provided the raw data for IEC 60479-1 and -2. Our study goal was to cover a wide range of stimuli durations, for which reliable data exists. Consistent data were found for stimuli durations covering the range of 1 μs - 300 s where VFTs were expressed as charge. The model predicted a transthoracic charge VFT of 1 mC at 1 μs duration. The charge VFT increased with stimulus duration and reached 10 C at 300 s. Presenting the first charge-based transthoracic VFT model covering stimuli durations over 1 μs - 300 s, we found 3 behavioral regions of charge VFT vs. duration. For short stimuli durations, 1 μs - 10 ms, VFTs followed a classic Weiss charge strength-duration curve. For long stimuli, longer than 5 s, charge VFTs can be approximated using a 38 mArms constant current model. From 10 ms to 5 s, charge VFTs tracked through a transition zone that could be approximated as a constant charge model Q≈100 mC.

Towards solving enigmas in electrical injury

The paper by Park and colleagues in the previous issue of Critical Care highlights vascular changes in electrical injury and finds them to be relatively long-lasting and significant. This finding is consistent with long-lasting disability seen clinically in electrically injured patients. Furthermore, the authors report that the changes seen in the shocked part of the body are accompanied by similar changes that are measurable in other parts of the body but that are not involved with electric current. This latter finding is of significant importance. A psychological syndrome - consistent and predictable - exists following an electrical injury. The causation is enigmatic. Recent psychiatric research indicates the importance of circulating cortisol and brain-derived neurotrophic factor (BDNF), which causes loss of hippocampal volume, in the genesis of depression. This psychiatric research has stimulated a speculative theory of the genesis of the psychological effects of electric shock. The paper by Park and colleagues is circumstantial support for the possibility that such a process is real and available.

Perceived electrical shock and Bayesian inference with multisensory stimuli

An electrical-accident victims recollection may be dramatically distorted by Bayesian inference in multisensory integration. Suddenly hearing the sound and seeing the bright flash of an electrical arc can cause a person to form the honest but false impression that they had experienced an electrical shock. Bayesian causal inference governs multisensory perceptual processing in general [1, 2]. If the sensory signals are largely consistent, the brain will infer a common cause for the signals and integrate them [1, 3-6]. Because an electric shock is often accompanied with certain visual, tactile, and auditory sensations, the prior expectation of a shock in presence of those sensations is high. Moreover, if the sensations are consistent with those of an electric shock and there is sufficient consistency in spatial and temporal attributes of the sensory signals to give rise to the inference of a common cause, there will be an illusory percept of an electric shock. Given that most people have no experience of past electric shocks, and therefore the “usual” electrical perception is not within their knowledge, it is easy for the brain to adopt those past reports from others and incorporate them into the reasoning. We do research on electrical injury or multisensory perception (SL) and wish to present this concept to emergency physicians with 2 cases. A 48-year old female was wiggling a vertical conduit out of the ground that had been the previous connection for her electric utility meter in Louisiana. These movements breached the deteriorating underground insulation for the 220 VAC 60Hz feeder line to her house. The utility company had neglected to disconnect this source at the power pole transformer. Internal conductors shorted together and the

Cardiac safety profile for Random Complex Waveforms

A rigorous method for assessing the Ventricular Fibrillation (VF) risk of a Random Complex Waveform (RCW) has not been previously available. Real-life hazardous events motivated us to develop such method. An RCW is observable and recordable. It consists of multiple different components randomly added one to the other. Assessment for VF risk exists for non-random waveforms, particularly VF thresholds for 50/60 Hz alternating currents, but not for RCWs.

The origin of remote symptoms in Electrical and Lightning Injuries: An attempt at explanation and a hypothesis for testing

A hypothesis is proposed for the causation of remote injuries from Electrical and Lightning Injuries(ELI). This theory takes instruction from recent developments in biological psychiatry and in particular the cortisol theory of depression. This is reviewed and its consequences are given. The theory is developed as follows. Cortisol is a known stress hormone, and is likely to be activated by the trauma of an electrical injury. Intense trauma chronically affects the control mechanisms for cortisol production leading to chronic cortisol level excess. Cortisol damages the areas of the brain involved in the memory, learning, and fluency dysfunctions seen in ELI, and leads to loss of volume of those regions, due to cell death. Cortisol levels affect the production of BDNF - Brain Derived Neurotropic Factor - in a proportion of individuals. BDNF exists in polymorphic forms and BDNF in one form can be severely depleted by stress. The brain loses its plasticity as a result. Depression results, and is of a type consistent with ELI. It is hoped this theory will lead to experiments to support it, and will guide the use of medication for the injury.