The acute management of patients with lightning injury presenting to the emergency department could be challenging. Emergency physicians should be aware, well prepared and respond appropriately and adequately to their conditions. The cardinal approach is to perform a thorough history and physical examination. It is also helpful to seek information from bystanders and eyewitnesses, as the patients themselves may not be able to give an adequate description, either because of the severity of injury or because of unconsciousness, confusion, and amnesia. The principle of reverse triage applies, in which the dead are treated first, as they may be resuscitated with rescue breathing alone.

Lightning injuries may occur as a result of six different mechanisms – direct strike; side flash; step voltage (also known as ground current); contact; upward streamer current and lastly blunt or concussive trauma as a result of shockwaves. A direct strike occurs when the lightning directly strikes the victim. It occurs in no more than 3% to 5% of injuries. Even though this mechanism seems intuitive to be the most likely cause of fatalities, this has not been shown in any studies [4, 5, 6]. A more frequent cause of injury, perhaps as much as 30% to 35%, is a side flash [4, 5, 6]. Side flashes occur when a lightning that has hit an object, such as a tree or building, travels partly down that object before a portion of the charge jumps to a nearby victim and cause injuries. More than 50% of the lightning injuries that take place outdoors are caused by side flashes from trees, when the tree is being used as a shelter from rain as in the case of our patients [5, 6]. Contact or touch potential injury occurs when the person is touching or holding the object to which the lightning strikes. It occurs in about 1% to 2% of injuries [4, 5, 6]. Step voltage is when the lightning hits the ground or a nearby object and travels through the ground to injure the victim. A recently identified mechanism is through connecting upward streamer current or leader current. Injury occur when a victim serves as the conduit for one of the usually multiple upward leaders induced by a downward stepped leader and its field during the event of the strike. It is probably a much underestimated mechanism of injury and may account for as much as 30% to 35% of injury cases [4, 5, 6, 7, 8]. Finally, victims may suffer from non-electrical blunt or concussive trauma as a result of shock waves created by the lightning. They may suffer from implosive and explosive forces created by the thunderclap with resulting contusions and pressure injuries, including tympanic membrane rupture and blunt trauma to major organ systems such as the brain, liver, and spleen.

It is noteworthy that victims of lightning strike are likely the result of multiple combinations of these mechanisms. It is the reason why victims present differently, and thorough evaluation is mandatory. In our series, the likely mechanism of injury was through a side flash as they were all sheltering under a tree struck by lightning. The concussive forces of the shockwaves produced by the lightning could also be considered as they complained of tinnitus and hearing loss. Those patients who complained of lower extremity cramps and numbness could be caused by step voltage mechanism wherein the lightning after hitting the tree, had traveled into the ground where our victims were sitting and standing.

The seizure experienced by one of the patients could be explained by the sudden large burst of electrical current into the nervous system disrupting the normal electrical activity of the brain. Seizures could also result from hypoxia and hemorrhage as a result of cardiorespiratory arrest and blunt trauma to the brain respectively. However, it is unlikely to be the cause in our case as our patient did not suffer from any of both events. The lightning victim may also experience loss of consciousness for varying periods [4, 12]. In a study conducted by Cooper, loss of consciousness occurred in about 72% of cases [4]. The lightning current can also affect the memory of the victim producing amnesia [4, 12].

Lightning can cause other minor symptoms that self-resolve, for examples, weakness, numbness and paresthesia [9, 11]. All of which were present in our patients. These symptoms could be due to intense vasospasm and vasoconstriction of blood vessels and restriction in blood flow (and thus oxygen) to a part of the body. The high current flow is thought to cause damage to the small blood vessels accompanying the nerves that control the muscles of the extremity involved, along with ischemia of these muscles [1]. It resolves spontaneously and requires no intervention [1]. This could also explain the mechanism of rhabdomyolysis as the case in two of our patients. The ischemia to the lower extremities as a result of vasospasm and the direct effect of the electrical current flowing into the muscle can result in muscle injury and eventual necrosis resulting in the release of muscle breakdown products such as CK¹¹. In our study, all patients have elevated levels of CK. However, not all their CK levels were significantly elevated to warrant a diagnosis of rhabdomyolysis.

Our third patient suffered serious otologic injury in the form of sensory-neural hearing loss on the right ear and a high frequency sensory-neural hearing loss on the left ear. None of them have ruptured tympanic membrane that occurs in about 20–50% of lightning-injured victims as a result of the shock wave created by the lightning flash [1, 13, 14, 15]. In some reports, even if the tympanic membrane remains intact, the victims may still suffer from varying degrees of permanent hearing loss and tinnitus [1, 9, 13, 14]. This is probably caused by the damage to the hair cells and nerves in the cochlea either from the shock wave or by the flow of current through it. The blast can also cause damage to ossicles that will result in conductive deafness, especially at high frequency [1, 13, 14, 15].

The current passing through the head and the strong radiation produced by the channel may cause a series of medical problems in the eyes of patients struck by lightning. It can cause inflammation, edema, burns, opacities, and ulcers leading to iritis, conjunctivitis, uveitis and cataract formation [16]. Development of cataract is the most common long-term injury reported [17]. It can occur in either or both eyes as a result of heat produced due to the current flow or due to exposure of the eye to very strong optical radiation including ultraviolet light [17]. It may occur days or years after the injury. Many eye problems develop over a long period, and so prolonged surveillance of a lightning strike survivor is necessary [1, 16, 17].

Follow ups on all the patients after they were discharged from the hospital showed no permanent disabilities except for the patient who suffered sensory neural hearing loss as repeated audiometry showed persistent abnormal results. On the other hand, the patient who had mild conjunctivitis had recovered without any complication. Likewise, those patients who suffered from rhabdomyolysis had decreasing CK levels. As of the date of writing this paper, there have been no further ED attendances from these patients related to lightning injury.