Environmental Emergencies Flashcards
Distribution of electrical injuries:
- Young children?
- Adults?
- Young children
oral contact w/ electric cords & outlets - Adults
construction and electrical workers (90% men)
MOI
1. Direct effect of electrical current on body tissues. Severity depends on? 5
- What results in deep and superficial burns?
- Which is usually a larger injury: exit or entrance?
- As current flows through the body, the greatest damage is sustained by what? 3
- Severity depends on
- voltage,
- duration,
- type (AC or DC),
- the current path throughout the body,
- environmental factors - Conversion of electrical energy to thermal energy
- Exit wounds
- nerves,
- blood vessels
- muscle.
- Low voltage AC current will cause muscular tetany, causing what?
- High voltage AC and DC currents cause a single violent muscular contraction, which tend to do what to the victim?
- the injured person to continually grasp the source, increasing contact time
- throw the victim from the source, thus increasing the risk of blunt trauma and blast injuries.
- Low voltage AC current tend to cause which arrhythmia?
2. High voltage AC and DC current tend to cause what? 2
- V-fib.
2. asystole and respiratory arrest.
PE: Neuro impairment occurs in approx. 50% of high-voltage injuries. What symptoms? 4
- Transient LOC
- Agitation, confusion
- Coma
- Visual disturbances
Pupils: may be fixed & dilated or asymmetric due to?
autonomic dysfunction, 50-80% of those struck by lightening have ruptured eardrums
- PE: Spinal cord injuries? 4
2. Peripheral nerves injuries often iinvolve what?
- Fractures
- The current itself
- Ascending paralysis, spinal cord syndromes
- Can be immediate, transient or delayed
- Injuries often involve the hand touching a power source
PE: Cutaneous wound management? 4
- Burns (entry and exit points)
- Look for entrance and exit wounds and degree of burns.
- Burns can be cleansed and dressed with silver sulfadizine.
- Extremities need careful exam for neurovascular compromise, compartment syndrome.
Extremities need careful exam for what? 2
- neurovascular compromise,
2. compartment syndrome.
- What has the highest resistance of any body tissue, generates the greatest amount of heat when exposed to electrical current?
- Areas of greatest destruction are often what?
- Deep electro-thermal tissue injury can result in what? 2
- Bone
- deep tissue surrounding long bones.
- edema &
- development of compartment syndrome.
Renal
1. What can occur and be complicated by pigment-induced renal failure?
- ___________ due to extravascular extravasation of fluid can lead to what? 2
- Rhabdomyolysis
- Hypovolemia,
- prerenal azotemia and acute tubular necrosis.
Treatment
1. Considered a trauma pt ? 2
- Dysrhythmias – management?
- Generally need aggressive what?
- What kind of fluid?
- ______ mg/kg over the first hour is appropriate for most patients.
- Acute hypotension should prompt a search for what?
- ABC’s, C-Spine….the stuff you know well by now!
- ACLS protocol
- fluid replacement
- Isotonic crystalloid fluid should be given.
- 20-40
- thoracic or intra-abdominal bleeding secondary to blunt trauma.
Electrical burn labs to order? 7
- Labs
- Lytes
- BUN/Creatinine
- Creatine kinase
- Serum and urine myoglobin
- CBC
- EKG
Electrical Burn Tx
Watch electrolytes closely.
Wound care - burn treatment as usual; may need transfer to burn unit.
1. Can cause?
2. Can cause what kind of failure?
3. If persistent and compartment syndrome has been excluded what may be necessary?
- Myoglobinurea
- Can cause renal failure
- amputation may be necessary
Tx for electrical burns:
- _______ prophylaxis.
- Treat any ________ appropriately.
- Which consults – this is trauma?
- Children with oral injuries need what?
- Pregnant women need what?
- Tetanus
- seizures
- General surgeon
- ENT.
- OB consult.
Electrical burns: Monitoring for? 5
- Continuous cardiovascular monitoring
- Arrhythmias do occur 15% of the time after electrical injury - Needs to be monitored for the development of compartment syndrome .
- I & O followed, maintain urine output > 100mL/h as a goal;
- monitor for rhabdomyolysis
- renal failure.
Lightening strikes:
1. Pathophysiology?
- Can result in? 4
- Lightning is a DC current
- Direct strike
- Side flash
- Ground current
- Step potential
Lightening strikes:
1. Extensive tissue damage and renal failure are common or rare?
- Immediate cardiac arrest from lightning strikes result from what?
- What can this lead to? - Respiratory arrest from ________ and paralysis of the what?
- rare.
- direct current depolarization of the myocardium and
- can result in sustained asystole. - depolarization
- medullary respiratory center.
Lightening strikes: Minor injuries? 7
Most minor injuries have a gradual improvement and no long term sequelae.
- Stunned patient
- Confusion, amnesia
- Short term memory problems
- Headache
- Muscle pain
- Parasthesias
- Temporary visual or auditory problems
Lightening Strike:
1. A diagnosis of lightning injury is based on history and should be considered in which patients?
- What may occur and have no prognostic value? 2
- What should alert the provider to potential lightning injury? 2
- found unconscious or in arrest who was outside during appropriate weather conditions.
- Pupil dilatation
- anisocoria
- Ruptured tympanic membranes or
- fern-like erythematous skin marking
Lightening strikes:
Treatment? 5
Secondary survey for occult injuries? 4
- Aggressive resuscitation
- ACLS and CPR
- Cardiac monitoring, SA02, BP
- Two large bore IV’s
- High flow 02
- Cutaneous burns
- Ocular involvement
- Auditory involvement
- Musculoskeletal fractures
Lightening Strike Labs 3
- Tetanus
- Moderate to severe injuries – admit to critical care unit
- Minor – admit, closely monitor cardiac and neuro status
Near-Drowning—Risk Factors
7
- Inability to swim or overestimation of swimming capabilities
- Risk-taking behavior
- Use of alcohol and/or illicit drugs
- Inadequate adult supervision
- Hypothermia which can lead to rapid exhaustion or cardiac arrhythmias
- Concomitant trauma, CVA or MI
- Hyperventilation prior to a shallow dive
PP of Drowning
1. After submersion, the degree of what determine the ultimate outcome? 2
- Drowning begins w/ period of what?
- Loss of?
- How does it change?
- After a while? - Leading to hypoxemia by: 2
- pulmonary and
- in particular CNS insult
- Panis
- Loss of normal breathing pattern
- Breath-holding, air hunger and struggle to stay above water
- Reflex inspiratory efforts occur - Aspiration
- Reflex laryngospasm
PP: Dry drowning
10-20% of submersion injuries
1. Cause by what?
-followed by? 2
- Wet drowning
What happens? 5
- laryngospasm,
- followed by hypoxia and LOC - Aspiration of water
- Dilution and washout of the pulmonary surfactant
- Diminished gas transfer
- Atelectasis
- Ventilation-perfusion mismatch
PP Fresh water drowning 1. Transient hemodilution causing what? 2. If large enough volume are what? -Leads to?
- causing blood cells to swell and burst
- If large enough volumes are aspirated,
- significant hemolysis is possible
PP
Salt water drowning
1. Lungs fill with salt water which draws blood where?
- Build up of what?
- stops what? from reaching the blood.
- out of the bloodstream and into the lungs
- sodium in the alveoli
- oxygen
End Organ Effects of drowing
- Pulmonary? 4
- Neurologic? 3
- Pulmonary:
- Fluid aspiration
- Both salt and fresh water wash out surfactant
- Producing noncardiogenic edema & acute respiratory distress syndrome (ARDS)
- S/S of ARDS: SOB, rales, wheezing - Neurologic:
- Hypoxemia & ischemia cause neuronal damage
- Can produce cerebral edema & elevated ICP
- 20% near-drowning victims sustain neurologic damage limiting functional recovery
End Organ Effects of drowning
- CV? 2
- Acid base and electrolytes? 2
- CV:
- Arrhythmias secondary to hypothermia & hyoxemia often occur
- Sinus bradycardia & fibrillation are more common - Acid-base & electrolytes:
- Metabolic and/or respiratory acidosis often occurs
- Significant electrolyte imbalances do not generally occur except those submerged in unusual media such as the Dead Sea
Drowning Management—Prehospital Care
3
- Assess the need for CPR—pulses may be weak
- Support the neck in a neutral position.
- Hypothermic patients should be rewarmed.
Heimlich maneuver or other postural drainage techniques are NOT proven to benefit—therefore rescue breathing should not be delayed.
Drowning Management—ER
3
- Prehospital resuscitative efforts should be continued
- Head and spinal cord injuries should be sought: often precipitate near-drowning
- Re-warming initiated in hypothermic patients
Drowning: How should you go about rewarming? 4
- Blankets
- Bair hugger
- Overhead warmers
- Resuscitative efforts should be continued until the patient’s temperature is 32-35C (90-95F)
Drowning Management—ER
Patients with GCS > or = to 13 4
- O2
- Observation for 4-6 hours
- If pulmonary exam and room air SA02 remain normal….discharge home with someone to watch
- If not better….. reassess and admit
Drowning Management—ER
Patients with GCS less than 13? 3
- O2 – ventilation support if needed
- Chest xray
- Labs
Drowning: Which labs for Patients with GCS less than 13?
9
- ABG’s
- CBC,
- CMP
- Could develop dilutional hyponatramia and have seizures
- PT/PTT,
- UA,
- CK,
- urine myoglobin,
- urine drug screen
Management–Inpatient
Neurologic - major determinants of neurologic outcome are:
3
- Duration of LOC
- Neurologic state of the patient at presentation
- Goal of management…..prevent secondary injury
Management–Inpatient
Goal of management…..prevent secondary injury such as? 5
- Cerebral edema
- Hypoxemia
- Fluid and electrolyte imbalances
- Acidosis
- Seizure activity
Management—Inpatient
Pulmonary? 4
- May need intubation for PEEP delivery: ARDS
- CXR’s should be performed only when indicated
- Bronchospasm is often seen and responds to beta agonists
- Glucocorticoids or prophylatic antibiotics are not helpful
Factors Associated with a Poor Prognosis
9
- Duration of submersion > 10 min
- Time to effective basic life support > 10 min
- Resuscitation duration > 25 min
- Hypothermia w/ core temp less than 33C (92F)
- Glasgow coma scale of 5 (comatose)
- Age less than 3YO
- Persistent apnea and requirement of CPR in the ER
- Arterial blood pH 10C (50F)
Hypothermia
- Defined as?
- Mild?
- Moderate?
- Severe?
- Defined as a core temperature of less than 35C (95F).
- Mild hypothermia - core temp 90-95F
- Mod hypothermia - core temp 82-90F
- Severe Hypothermia - core temp less than 82F
While mostly seem in cold climates, can develop without exposure to extreme environmental conditions.
Hypothermia at risk population? 4
- Elderly lose their ability to sense cold.
- Neonates have large surface-to-volume ratio.
- Both groups have limited ability to increase heat production and conserve body heat.
- Individuals with an altered sensorium.
PP of hypothermia:
1. Heat is generated by cellular metabolism (prominently what? 2)
- Loss by the skin and lungs though?
4
- (heart & liver)
- Evaporation
- Radiation
- Conduction
- Convection
Hypothermia
Heat is preserved by? 3
- Peripheral vasoconstriction
- Shivering
- Non-shivering thermogenesis
What is non-shivering thermogenesis?
Increase in metabolic rate from thyroid and adrenal glands
Presentation of Hypothermia
- Mild? 7
- Moderate? 9
Mild:
- Tachypnea,
- tachycardia,
- hyperventilation
- Ataxia,
- dysarthria,
- impaired judgement
- Shivering and “cold diuresis”
Moderate:
- Reductions in pulse rate & cardiac output…
- hypoventilation…
- A fib….
- junctional bradycardia & other arrhythmias can occur
- CNS depression,
- hyporeflexia
- Decreased renal blood flow and
- loss of shivering
- Paradoxical undressing
Hypothermia Presentation
Severe? 7
- Pulmonary edema
- Oliguria
- Areflexia
- Coma
- Hypotension,
- bradycardia,
- ventricular arrhythmias and asytole
Dx of Hypothermia
- Must use what kind of thermometer?
- Labs to ID potential complications? 5
- Must use low-reading thermometer.
- Labs to ID potential complications:
- Electrolytes
- Hematocrit
- Coagulation studies
- ABGs
- EKG: elevation of the J point—J or Osborne wave
EKG reading for hypothermia?
J waves
Managment of ABC’s
Initiation of rewarming
2
- Passive external rewarming
2. Active external rewarming
Active external rewarming:
- Ways to do this? 4
- Risk is what?
- Warm what part of the body first?
- Combination of
- warm blankets,
- radiant heat,
- warm baths or
- forced warm air. - Risk is core temperature afterdrop—occurs when trunk and extremities warmed simultaneously.
- Warm trunk 1st and minimize use of peripheral muscles .
Active internal rewarming:
Can be used alone or with active external rewarming.
Ways you can do this? 4
- Pleural and peritoneal irrigation with warm saline.
- Hemodialysis and cardiopulmonary bypass.
- Warm humidified oxygen.
- Warm IV fluids and bladder or GI irrigation with warm saline may be used.
Treatment of Arrhythmias
- Hypothermic heart very sensitive to what?
- Which usually resolve with rewarming? 2
- Management of V-fib and asystole can be difficult—they may be refractory to therapy until the patient has been what?
- movement & rough handling of the patient may precipitate arrhythmias.
- A fib and flutter
- rewarmed (core temp of 86-90F).
