Rami Khouzam, MD

The Statue of Zeus at Olympia• An enormous statue of the

Greek father of gods, carved by the great sculptor Pheidias

• In his right hand a figure of Victory made from ivory and gold. In his left hand, his scepter inlaid with all metals, and an eagle perched on the sceptre

• The sandals of the god are made of gold, as is his robe

Pausanias the Greek (2nd century AD)

7 Wonders of the Ancient World• Today, archaeological evidence reveals some of the

mysteries that surrounded the history of the Wonders for centuries

• For their builders, the Seven Wonders were a celebration of religion, mythology, art, power, and science

• For us, they reflect the ability of humans to change the surrounding landscape by building massive yet beautiful structures, one of which ( the Pyramid) stood the test of time to this very day

Index Case• 42-year-old white male

• No significant past medical hx. except x possible marijuana

• Was working on a ladder 12 feet high

• Electrocuted with 440 volts

• Contact burns to bilateral hands

• Cardioversion done 5 times

• Prior to arrival to the hospital:

• SVT --> Cardioversion x 5

• Hypotension --> Dopamine and Epinephrine drips

• Intubated

• Vitals on arrival:– Pulse: 101– BP: 71/46– RR: 24

PE (pertinent findings):

• Neck in C-collar

• Ears: some blood behind Lt. tympanic membrane

• Chest: Bilateral crackles

• Heart: S1S2 RRR Few extra-beats, No m,g,r

• Upper extremities: 2nd & 3rd degree burns on the palmar aspects of both hands

• Labs:

• K: 3.1, Cr: 1.1

• WBCs: 27.8 10.5

• AST/ALT: 63/54

• ABGs: 7.25/43.8/213.7/18.6/99.1%

• Lactic a: 4.2

• UDS: + methamphetamine

Trop 1.38 2.87 1.81

CK 9892190

CKMB 19.417.2

CKMB index 2.0 0.8

Myoglobin > 500 > 500

Swan-Ganz:

• PCWP: 19

• PA: 31/14

• CVP: 15

• CO: 16 / CI: 11

• SVR: 335

• MAP: 80

CXR:

• Interstitial & alveolar pulmonary opacities centrally with relative sparing peripherally:

consistent with pulmonary edema

TTE on admission

• Mild eccentric LVH

• LV systolic function was moderately to severely decreased

• EF: 25-30%

Day 3:

• Levophed discontinued

• Weaned off of the vent & extubated

• Blood culture: MRSA

Day 8:

• Discharged home on: pain meds & antibiotics

TTE (prior to d/c)

• Normal left ventricular systolic function

• EF: 65%

The Hanging Gardens of Babylon

• A palace with legendary gardens built on the banks of the Euphrates river by King Nebuchadnezzar II

ELECTRICAL INJURIESCritical Care Medicine

Volume 30.Number 11.November 2002

• Adults in workplace, children at home

• Severity of injury depends on:– Intensity of electrical current (voltage of

source and resistance of victim)– Pathway through victim’s body– Duration of the contact with the source

Immediate death may occur from:

1) Current-induced ventricular fibrillation

2) Asystole

3) Respiratory arrest secondary to:– Paralysis of the central respiratory control

system– Paralysis of the respiratory muscles

History Overview• Lightning was

attributed to supernatural powers

• Zeus ruler of the ancient Greek gods holding thunderbolts which he used as warning or punishment against who disobeyed him

• Zeus, the youngest son of Cronus and Rhea, was the supreme ruler of Mount Olympus and of the Pantheon of gods who resided there

• Being the supreme ruler he upheld law, justice and morals, and this made him the spiritual leader of both gods and men

• Zeus was a celestial god, and originally worshiped as a weather god by the Greek tribes

• He has always been associated as being a weather god, as his main attribute is the thunderbolt, he controlled thunder, lightning and rain

• Theocritus wrote circa 265 BCE: "sometimes Zeus is clear, sometimes he rains”

• He is also known to have caused thunderstorms

• Discovery and widespread use of electricity in the mid-1800s took away the supernatural aura

• 1st electrical fatality recorded in France in 1879

• Thomas Alva Edison was both a scientist and an inventor

• Born in 1847

• When Edison was born, society still thought of electricity as a novelty, a fad. By the time he died, entire cities were lit by electricity

• In his lifetime, Edison patented 1,093 inventions

• The most famous of his inventions was an incandescent light bulb

• He believed in hard work, sometimes working twenty hours a day. Edison was quoted as saying, "Genius is one percent inspiration and 99 percent perspiration"

• In tribute to this important American, electric lights in the United States were dimmed for one minute on October 21, 1931, a few days after his death

• Electrical injuries (excluding lightning) are responsible for > 500 deaths/year in the US

• > 1/2 of them occur in the workplace.

• 4th leading cause of work-related traumatic death

• Electrocutions at home: > 200 deaths/year

• Lightning responsible for 93 deaths/year in US

• Morbidity 5-10 times higher than that due to other forms of electrical injury

• Iatrogenic electrical injury in the ICU: defibrillators, pacemakers, electrosurgical devices

• Story of CPR: how to treat electrocuted electrical linemen who were in VF

Principles of Electricity

• Electricity: flow of electrons (negatively charged outer particles of an atom) through a conductor

• When the electrons flow away from this object through a conductor they create an electric current: amperes

• Voltage: force that causes electrons to flow: volts

• Anything that impedes the flow of electrons through a conductor creates resistance: ohms

• Power lines range from:– Low: < 600 volts

– Ultrahigh: > 1 million volts

• Utility power lines with high voltages in sparsely populated areas

• Through a succession of transformers voltage is gradually reduced

• Most homes in US & Canada have a 120/240 V other countries (Europe, Asia..): 220 V

The Temple of Artemis at Ephesus

• A beautiful temple in Asia Minor erected in honor of the Greek goddess of hunting and wild nature

Pathophysiologic effects of Different Intensities of

Electrical Current

• Electrical current exists in 2 forms:

1) AC: (Alternating Current): when electrons flow back and forth through a conductor in a cyclic fashion

• It is used in household and offices and is standardized to a frequency of 60 cycles/sec (60 Hz)

2) DC: (Direct Current): when electrons flow only in one direction

• Used in certain medical equipment: defibrillators, pacemakers, electrical scalpels

• AC is far more efficient and also more dangerous than DC (~ 3 times): tetanic muscle contractions that prolong the contact of victim with source

• Issue of safety over efficiency: early days of electricity when Thomas Edison (who developed and popularized DC was fighting against George Westinghouse (who developed AC)

• AC: first death penalty by electrocution

• Lightning is a form of DC

• Occurs when electrical difference between a thundercloud and the ground overcomes the insulating properties of the surrounding air

• Current rises to a peak in about 2 µsec

• Lasts for only 1-2 sec

• Voltage >1,000,000 V

• Currents of >200,000 A

• Transformation of the electrical energy to heat generated temperatures as high as 50,000ºF

• Extremely short duration prevents from melting

The Mausoleum at Halicarnassus

• A fascinating tomb constructed for King Maussollos, Persian satrap of Caria

Determinants of Electrical Injuries

• Ohm’s law:

Current = Voltage/Resistance

• Exposure of different parts of the body to the same voltage different current different degree of damage because resistance varies

• The least resistance is found in nerves, blood, mucous membranes and muscles

• The highest resistance is found in bones, fat and tendons

• Skin’s resistance ranging between 40,000 and 100,000 Ω depending on thickness

• Moisture of the skin; electrocution of a person in a bathtub or swimming pool

• Moist mucus membranes: significant orofacial injury to infants and toddlers

• Nerves and blood vessels are the best conductors: path of least resistance for current after it enters the body

• Duration of the contact: shock caused by AC will produce bigger injury than shock caused by DC of the same amperage

Pathway of the current through the body:

– Vertical pathway parallel to the axis of the body is the most dangerous. It involves all the vital organs; central nervous system, heart, respiratory muscles, in pregnant women the uterus and fetus

– Horizontal pathway from hand to hand: the heart, respiratory muscles and spinal cord

– Pathway through the lower part of the body: local damage

The Colossus of Rhodes

• A colossus of Helios the sun-god, erected by the Greeks near the harbor of a Mediterranean Island

Electrical Injury to Specific Tissues & Organs

Cardiovascular System:

Pathophysiology:

• Direct necrosis of the myocardium

• Cardiac dysrhythmias

• Focal or diffuse

• Widespread, discrete, patchy contraction band necrosis involving the myocardium, nodal tissue, conduction pathways and coronary arteries

• A current > 50-100 mA with hand-to-hand or hand-to-foot transmission ventricular fibrillation

• High-voltage current (AC or DC) ventricular asystole

• Lightning cardiac standstill

• Sinus rhythm may spontaneously return

• Cardiac dysrhythmias reported in survivors of electrical injuries pathogenesis is rather unclear, multifactorial

• Possible mechanisms:

1) Arrythmogenic foci due to myocardial

necrosis (esp. SA Node injury)

2) Alterations in the Na+ - K+ adenosine triphosphatase concentration

3) Changes in the permeability of myocyte membranes

4) Anoxic injury (respiratory arrest precedes the injury to the heart)

• Large arteries not acutely affected because their rapid flow:dissipate heat. Medial necrosis: aneurysm formation and rupture

• Smaller vessels acutely affected d.t. coagulation necrosis compartment syndrome

Clinical Manifestations

• Cardiac standstill, ventricular fibrillation: most serious

• Sinus tachycardia, nonspecific ST- and T-wave changes: much better prognosis

• Conduction defects, various degrees of heart blocks, BBB and QT interval

• Supraventricular tachycardias and atrial fibrillation: usually do not cause significant hemodynamic compromise

• On echocardiogram: some depression of the right & left ejection fractions

Cutaneous Injuries & Burns

• Extensive flash and flame burns

• Hemodynamic, autonomic, cardiopulmonary, renal, metabolic and neuroendocrine responses

Nervous System• Loss of conciousness, confusion & impaired recall

• Peripheral motor & sensory nerves motor & sensory deficits

• Seizures, visual disturbances & deafness

• Hemiplegia, quadriplegia, spinal cord injury

• Transient paralysis, autonomic instability hypertension, peripheral vasospasm due to lightning from massive release of catecholamines

Respiratory System

• Direct injury to the respiratory control center cessation of respiration or suffocation secondary to tetanic contractions of the respiratory muscles

• Acute respiratory dysfunction syndrome secondary to ischemia, aggressive fluid resuscitation, ventilator-associated pneumonia

Other Systems• Kidneys susceptible to anoxic/ischemic injury

• Release of myoglobin & creatinine phosphokinase renal tubular damage renal failure

• Fractures

• Transient autonomic disturbances fixed pupils may be perceived as severe brain injury or even death

• Temporary sensorineural hearing loss

The Lighthouse of Alexandria

• A lighthouse built by the Ptolemies on the island of Pharos off the coast of their capital city

Management of Electrical Injuries

Overall fluid management should be judicious unless: SIADH

Patient Monitoring

• Most severe cardiac complications present acutely

• Very unlikely for a patient to develop a serious or life-threatening dysrhythmia hours or days later

• Asymptomatic normal ECG do not need cardiac monitoring

• Preexisting heart disease: monitor such patients for 24 hrs after the injury

• Criteria for cardiac monitoring:– Exposure to high voltage– Loss of consciousness– Abnormal ECG at admission

• Type of cardiac monitoring: (controversial)

– Continuous telemetry

– Serial ECGs

– Serial measurement of cardiac enzymes

• Prognostic value of CK-MB, noninvasive and invasive imaging studies (echocardiography, thallium studies & angiography): rather poor and inconsistent

• Muscles injured by an electrical current can contain up to 25% CK-MB fraction (as opposed to the normal 2-3%)

• No information regarding changes in troponin

Prophylaxis...

“One ounce of prevention is worth a pound of treatment”

The Great Pyramid of Giza

• A gigantic stone structure near the ancient city of Memphis, serving as a tomb for the Egyptian Pharaoh Khufu

“Man fears Time, yet Time fears the Pyramids”

Arab proverb

"Genius is one percent inspiration and 99 percent perspiration."