Wilderness Medicine · Supplementary · from Wilderness Medicine

Case 2: Lightning Strike Injury

Patient Presentation

Demographics: 24-year-old female park ranger

Chief Complaint: "She was struck by lightning on the trail — she was unconscious for a couple of minutes and now she can't hear."

History of Present Illness: Ranger M.J. was leading a group of 8 hikers along an exposed alpine ridge trail at 3,200 m elevation when a sudden thunderstorm developed. While attempting to guide the group below treeline, she was struck by lightning via a side flash/splash mechanism — lightning struck a nearby metal trail sign and arced to the patient, who was approximately 2 meters away. Witnesses report she was thrown approximately 1.5 meters, was motionless and pulseless for an estimated 60-90 seconds, then began gasping and moving spontaneously.

Upon regaining consciousness approximately 2 minutes after the strike, she was confused and disoriented, complained of severe bilateral hearing loss with tinnitus, and reported burning pain in her left arm and left leg. She had no memory of the event (retrograde amnesia). One of the hikers, a nurse, performed a primary survey: airway patent, breathing spontaneously, pulse present (irregular), GCS improved to 14 within 10 minutes.

On further assessment by a wilderness EMT who arrived within 45 minutes, she was noted to have Lichtenberg figures (ferning pattern) across her left shoulder and arm, first-degree burns at the left hand (metal watch), and bilateral tympanic membrane ruptures. She was unable to hear conversational speech. She complained of bilateral lower extremity weakness and paresthesias.

Past Medical History:

• No significant medical history
• No prior lightning exposure or electrical injury
• Up to date on tetanus immunization

Medications:

• Oral contraceptive pill
• Multivitamin

Social History:

• Non-smoker, occasional alcohol
• Avid outdoor enthusiast (hiking, climbing, skiing)
• 3 years as a National Park Service ranger
• Wilderness First Responder certified

Family History:

• Non-contributory

Physical Examination

• Vital Signs: BP 102/68 mmHg, HR 108 bpm (irregular), RR 18, SpO2 97% on room air, Temp 36.2°C (mild hypothermia from rain and exposure), GCS 14 (E4V4M6)
• General: Alert, anxious, communicating via hand signals and lip reading due to hearing loss
• HEENT:
• Eyes: bilateral fixed dilated pupils (6 mm bilateral — autonomic dysfunction, not necessarily indicative of brain injury in lightning); corneas clear; no hyphema
• Ears: bilateral tympanic membrane perforation (right: central perforation ~40%; left: marginal perforation ~60%); hemorrhagic otorrhea bilaterally; unable to hear conversational speech bilaterally (estimated >60 dB hearing loss); no hemotympanum beyond TM rupture
• Oropharynx: clear, no burns
• Skin/Burns:
• Lichtenberg figures (pathognomonic ferning/fern-like pattern): extending from left shoulder across left deltoid to left forearm — superficial, non-blanching, arborescent erythema
• First-degree burn with central blister at left wrist (beneath metal watchband — contact point)
• Linear burn along left lateral leg (flashover path)
• Total body surface area (TBSA) burned: <2% (superficial)
• Cardiovascular: Irregular rhythm; no murmurs; distal pulses present but diminished in left upper extremity; capillary refill 3 seconds left hand
• Neurological:
• Mental status: oriented to person and place, not time; retrograde amnesia for event; anterograde memory impaired (cannot recall 3 objects at 5 minutes)
• Motor: lower extremity weakness bilateral — hip flexion 3/5, knee extension 4/5, ankle dorsiflexion 4/5 (keraunoparalysis — lightning-specific transient paralysis)
• Sensory: diminished sensation bilateral lower extremities below knees; paresthesias bilateral feet
• Reflexes: absent bilateral lower extremities (areflexia — consistent with keraunoparalysis)
• Upper extremity exam: left grip strength reduced 3/5; right 5/5
• Musculoskeletal: No obvious fractures on palpation; no spinal tenderness; no compartment syndrome signs

Workup and Results

Laboratory Studies:

Imaging/Additional Studies:

• Field ECG (portable monitor): Sinus tachycardia with frequent PVCs; QTc prolonged at 510 ms; no ST elevation or depression; no evidence of acute MI pattern
• Hospital ECG (4 hours post-strike): Sinus rhythm, 96 bpm; PVCs decreased; QTc 480 ms; diffuse T-wave flattening
• CT head (hospital): No intracranial hemorrhage, no fracture, no edema
• CT cervical/thoracic/lumbar spine: No fractures
• Chest X-ray: No pneumothorax, no pulmonary contusion
• Echocardiogram (hospital): Normal LV function, EF 55%; no regional wall motion abnormalities; no pericardial effusion; mild tricuspid regurgitation
• Audiometry (day 3): Bilateral mixed hearing loss — conductive component from TM perforation + sensorineural component (likely cochlear blast injury); right ear: 55 dB PTA; left ear: 65 dB PTA

Clinical Image

Illustration depicting the mechanisms of lightning injury (direct strike, side flash, ground current, contact, upward streamer), pathognomonic Lichtenberg figures, and the concept of keraunoparalysis with autonomic dysfunction. Source: Educational illustration.

Diagnosis

Lightning Strike Injury (Side Flash Mechanism) with Cardiac Contusion, Keraunoparalysis, Bilateral Tympanic Membrane Rupture, Rhabdomyolysis, and Traumatic Brain Injury (Mild)

Key Diagnostic Criteria:

• Witnessed lightning strike with transient cardiopulmonary arrest and spontaneous ROSC
• Lichtenberg figures (pathognomonic for lightning injury — not seen in other electrical injuries)
• Keraunoparalysis: bilateral lower extremity paralysis with areflexia and autonomic dysfunction (fixed dilated pupils, vasospasm) — a transient phenomenon unique to lightning injury
• Bilateral TM perforation (blast effect from thunder/pressure wave — occurs in >50% of lightning strike survivors)
• Elevated troponin and CPK indicating cardiac and skeletal muscle injury
• Myoglobinuria indicating rhabdomyolysis
• Prolonged QTc (risk of torsades de pointes)

Treatment Plan

1. Field management (immediate):

• C-spine stabilization (fall/throw mechanism)
• Continuous cardiac monitoring (portable); have AED immediately available
• IV access: normal saline bolus 1L for rhabdomyolysis prevention
• Protect from hypothermia (remove wet clothing, insulate)
• Reassess neurological function every 15 minutes (keraunoparalysis should begin improving within 1-4 hours)
• Do NOT be deceived by bilateral fixed dilated pupils — this is autonomic dysfunction, not brain death, in lightning victims

1. Hospital management:

• Cardiac: Continuous telemetry for minimum 24 hours (risk of delayed arrhythmias with prolonged QTc); serial troponins Q6H x 24 hours; repeat echocardiogram at 48 hours; electrolyte correction (potassium trending high — avoid further supplementation)
• Rhabdomyolysis: Aggressive IV fluid resuscitation (NS at 200-300 mL/hr targeting UOP 200-300 mL/hr); consider sodium bicarbonate drip to alkalinize urine (target pH >6.5); monitor CPK, myoglobin, creatinine, potassium Q6H until trending down
• Renal protection: Maintain high urine output; avoid nephrotoxins; consider mannitol if urine output drops despite aggressive hydration

1. Otologic management:

• ENT consultation for bilateral TM perforations
• Keep ears dry; no ear drops initially
• Serial audiometry at 2 weeks, 6 weeks, 3 months
• Most TM perforations from lightning heal spontaneously (85%); tympanoplasty if no healing by 3 months
• Sensorineural component may be permanent

1. Neurological follow-up:

• Serial neurological exams; keraunoparalysis expected to resolve within 24 hours (if not, investigate for spinal cord injury)
• Neuropsychological testing at 2 weeks and 3 months (lightning survivors have high incidence of persistent cognitive deficits: memory impairment, attention deficits, personality changes)
• MRI brain if cognitive symptoms persist

1. Burns: Wound care for superficial burns; Lichtenberg figures are not true burns and require no specific treatment (they resolve within 24-48 hours)
2. Psychological support: Referral for PTSD screening and treatment (high incidence in lightning survivors); Lightning Strike and Electric Shock Survivors International (LSESSI) peer support referral

Key Learning Points

• Lightning injury is unique among electrical injuries: the current flow is extremely brief (1-5 milliseconds) and flows primarily over the body surface (flashover effect), resulting in relatively low internal tissue damage compared to high-voltage electrical injuries; however, cardiac arrest is the primary cause of death
• The reverse triage principle applies in mass lightning casualty events: treat the apparently dead first (those in cardiac arrest), as they have the best chance of survival with immediate CPR; those who are conscious are likely to survive without immediate intervention
• Keraunoparalysis (lightning-specific transient paralysis with autonomic dysfunction) is self-limiting and resolves within hours; bilateral fixed dilated pupils in lightning victims do NOT indicate brain death and should NOT be used as criteria to withhold resuscitation
• Tympanic membrane rupture is the most common physical finding in lightning strike survivors (>50%) and serves as a marker of significant exposure; bilateral perforation suggests close proximity to the strike point
• Lightning injury survivors frequently develop delayed neuropsychiatric sequelae including PTSD, depression, chronic pain, cognitive impairment, and personality changes; long-term follow-up and psychological support are essential

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