Transcript Near-Drowning

Drowning
New Definitions and Protocols
Charles Stewart MD, EMDM
Director of Research
University of Oklahoma
Tulsa School of Community Medicine
Oklahoma Institute for Disaster and Emergency Medicine
Drowning
• Much of our experience with the
resuscitation of patients is a direct result
of man’s ventures into the water.
Drowning
• Demographics
– 6,000 - 8,000 deaths per year
– The 3rd leading cause of accidental death
in USA
– The 2nd leading cause of death in children
– 25,000 rescues each summer on California
beaches
Drowning
• Statistical Risk Factors
– Age: Youth 40% under 4 years old
– Location: Pools, bathtubs, lakes, rivers
– Sex: Male 3:1
– Time of year: Warm months
Drowning
• We really don’t know how many ‘near’
drownings occur each year.
– Death statistics are readily available
– >15% of school children have at least one
submersion incident per year.
– With 7.4 per 100,000 reported mortality,
that means at least ½ million per year in
South Carolina alone!.
Near Drowning
• Statistical Risk Factors
– Predisposing Illnesses: Epilepsy, seizures
– Trauma: Diving and boating accidents, falls
– Mental impairment: Drugs and alcohol
Near Drowning
• Most common sites:
– Fresh inland bodies of water
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Lakes
Rivers
Quarries
Residential swimming pools
Predisposing Factors
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Coma, seizures
Alcohol/Drugs
Exhaustion
Hyperventilation
Rapidly moving water
Predisposing Factors
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Poor swimming ability
Exhaustion
Panic
Hypothermia
Trauma
Near Drowning
Murder ???
Suicide ???
Near Drowning
Definitions
Definitions were revised at 2002 World
congress on Drowning in Amsterdam,
Netherlands. They are now
internationally accepted and more
uniform
Near Drowning
Survival beyond 24 hours after
immersion.
This definition is no longer used…
Drowning
Submersion in a fluid resulting in immediate death or
death with 24 hours
Respiratory impairment from submersion
in a liquid. May have outcome of death,
morbidity, or no morbidity
Drowning
The fluid does not have to
be water
Drowning
• Unconsciousness
– Due to :
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Trauma
Seizure
Coma
Drug/Alcohol abuse
Drowning Pathophysiology
• 3 Major metabolic abnormalities
– Anoxia
– Acidosis
– Hypercapnia
Wet Drowning
• Approximately 90% of drowning victims
– aspirate water
– vomit
– cough
– gasp
– flood lungs with water
Pathophysiology with aspiration
• Hypoxemia
– Occurs whether or not patient aspirates
– 85-90% aspirate
– 10-15% DO NOT aspirate
Pathophysiology without aspiration
• Severe, persistent laryngospasm
• Anoxic seizures
• Death
Pathophysiology with aspiration
• Hypoxemia
– Asphyxia starts the Hypoxia
– Intrapulmonary shunting leads to further
hypoxemia
– Pulmonary damage continues the process
Does the type of
aspirated water matter?
Pathophysiology
• Consequences of Aspiration
– Few survivors of drowning aspirate enough
water to cause significant changes in either
blood volume or serum electrolytes.
Pathophysiology
• Consequences of Aspiration
– 2.2 cc/kg
– 11 cc/kg
– 22 cc/kg
Hypoxia
Blood volume changes
Electrolyte changes
• Average aspiration is only 2-4 cc/kg
Pathophysiology with aspiration
• Pulmonary Edema
– Damage to Alveolar membrane
– Damage to pulmonary microcirculation
Salt
vs
Fresh
There are REAL differences
Near Drowning
• Potential Fresh Water Damage
– Hypoxia
– Atelectasis
– Pulmonary Edema
– Hypotonic
– Hemolysis
• Lowered Na, Cl, and K
Strips surfactant
Potential Fresh Water
Damage
• Hypoxia
• Atelectasis
• Pathogenic bacteria and impurities
lethal
• Produces greater long-term damage
due to salt in pulmonary edema
Drowning
• Potential Salt Water Damage
– Hypovolemia if large amounts swallowed
– Hypertonic
Elevation of Na, Cl and K,
decrease blood volume
• Salt water is 2 times as lethal
Drowning Final Pathway
• Pulmonary Edema
• Hypoxia
COLD WATER
and
WARM WATER
drownings are different
Warm Water
• 20oC and above
• 72oF and above
• Lakes, ponds, quarries
Hot Water
• Body temperature and above
• Hot tubs, bath tubs, hot springs
Warm Water Drownings
• 49 Warm Water Drownings in Children
– 29 died
– 13 neurological cripples
– 7 survived intact
58%
27%
15%
Cold water has more survivors
Very Cold Water
• The definition is not easy
– It is usually below 21oC or (71oF)
6
Hours
5
100% Lethal
50%
unconscious
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3
Probable
Drowning
2
Safe
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20
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30
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40
4
Water Temperature
50
10
Mammalian Diving Reflex
• Circulatory system shunts blood to the
brain and heart from extremities, GI
tract and skin
• Apnea and bradycardia follow, allowing
prolonged submersion
Mammalian Diving Reflex
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Found in all mammals
Heart Rate Slows
Airway closes
Circulatory system shunts blood to brain
and heart from extremities, GI tract and
skin
• Apnea and bradycardia follow, allowing
prolonged submersion
Mammalian Diving Reflex
• Mammalian Diving Reflex in Humans
– Not very active
– Probably not the mechanism for survival in
prolonged submersions in children
Immersion syndrome
• Sudden exposure to very cold water.
• Probably vagal dysrhythmia
– Asystole
– Ventricular fibrillation
– Alcohol and intoxicants are predisposition
Immersion Hypothermia
A special case….
Cold water immersion
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Survival Times - Persons of Average Build
Water Temperature
Survival Time
0 Deg C
45 minutes
9.5 deg C
2 to 3 hours
11 deg C
4 hours
14 deg C
6 hours
18 deg C
10 hours
Immersion hypothermia
• Huddle
• HELP
Submersion victims
aren’t dead until
they are WARM and DEAD
Field Management
Drown not thyself to save a
drowning man
Old Proverb
Rescue
• Most people drown within 10 to 30 feet
of safety.
– Reach
– Throw
– Row
– Go?
American Red Cross
Scene Assessment
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Type of incident?
Duration of submersion?
Type and temperature of water?
Duration of on scene CPR?
Prior health of patient?
Drug and Alcohol use?
Near Drowning
• Watch for trauma in rapidly moving
water
Resuscitation
#1
Restore Ventilation !!!
CPR
• Cardiopulmonary Resuscitation
– The immediate actions of the Primary
Responder significantly affects the
outcome of the near drowning victim
Field Management
In near drownings that involve falls,
moving water, boating, and surfing
accidents.
Always take C-spine precautions
The Heimlich Maneuver
is unproved in near drownings
Emergency
Department
Management
Intubate
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Secures airway
Protects against aspiration
Allows suction of secretions
Better ventilation
Suction
• Suction equipment must be available
• Many patients will vomit
• Many will have heavy secretions form
pulmonary edema
Emergency Department
Management
• Cardiac monitoring needed for all
patients
• Acidosis and Hypoxia will decrease the
fibrillation threshold
Emergency Department
Management
• Core body temperature should be
measured
• Keep patient dry
History of Patient
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Obtain Medical History ASAP
Age
Pre-existing diseases
Physical condition
Medication
Near Drowning
• In near drowning victims suspect:
– Child abuse
– Suicide
– Attempted murder
– Cervical spine trauma
– Seizures
– Drug/Alcohol abuse
Emergency Department
Management
• Reassess ABC’s and vital signs
frequently
• Include Neuro checks
Emergency Department
Management
• Neurological deficit should not be
assumed to be anoxic until
– C-spine
– Intracranial Injury
– Toxic encephalopathy
• Have been ruled out
Laboratory
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Arterial blood gases
Electrolytes
BUN/ Creatinine
Platelets/ PT & PTT/ CBC
Serum & Urine Hemoglobin
Clinical Manifestations
• Radiographic Changes
– Non-cardiac pulmonary edema with normal
heart size
– Perihilar pattern
– Seen in 1/3 to 2/3 of patients initially
Adjunctive Therapy
Hypoxia
• Respiratory Management Objective
– Try to achieve a Pa O2 of 70-100 mm Hg
– 70% will require more aggressive therapy
PEEP
• Indicated when pO2 < 60 and FIO2 > 50
• Try to keep the pO2 at 75-90
• This prevents pulmonary edema and
ARDS ??? (acute respiratory distress
syndrome)
Hypoxia
• Bronchospasm
• Treat with:
– A) Nebulized Agents
– B) Theophylline
– C) Consider steroids
Steroids
As always .... controversial
Infection
• Prophylactic Antibiotics
– Not usually indicated
– Septic tank?
– Daily gram stains
– Treat the proper bug
Experimental Therapies
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? Controlled hypothermia
? Calcium channel blockers
? Barbiturate coma therapy
? Hyperbaric oxygenation
? Hyperventilation
Hospital Management
• Resuscitation
• Cerebral resuscitation
– HYPER regimen advocated in comatose
children
• ??? Utility
Disposition
• All patients with submersion injuries
should be admitted
• High incidence of delayed complications
Patients should be admitted
and observed ...
But for how long?
Disposition
• WARD BED - Asymptomatic with
normal vital signs, CXR,
and ABG
• ICU - Symptomatic or abnormal vital
signs, CXR, or ABG
Prognosis
Prognosis
• Survival depends upon a variety of
interrelated factors
– Age
– Underlying disease
– Water type and temperature
– Duration of submersion
– Degree of hypothermia
Clinical Manifestations
• Neurological Damage
• Flaccid is BAD!
Bad Prognostic Factors
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Older age
Warm water
Spinal cord damage
Inadequate CPR
Decorticate / Decerebrate
Unconscious
Septic tank
Good Prognostic Factors
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Older child or young adult
Cold water
Adequate CPR/on scene ACLS/BLS
Conscious
Short submersion
Healthy
Warm Water Submersion
• In warm water submersion
– Submersion > 5 minutes
– Fixed and dilated pupils (in the ED)
– No CPR for 10 minutes or more
– pH less than 7.1 on arrival at hospital
– Need for in hospital resuscitation or
ventilation
• Severe neurologic impairment or
mortality is likely
Check the K!
• Potassium of > 10 is uniformly
associated with mortality…
– OK to call the arrest at this point.
Prevention
Prevention
Prevention
Prevention
Prevention
Prevention
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Fences
Self-locking gates
Immersion alarms
Keep pool full
Prevention
• Decrease intoxicants around the pool!
Prevention
• Proper protective gear
– survival suit
– Flotation device
• Cold water training
Prevention
• Supervise patients with seizures
• Other handicaps?
Prevention
• Prevention Tips
– Swimming lessons
– Appropriate people to watch children
– Teach children to obey the swimming pool
rules
Prevention
• Prevention tips
– Don’t mix alcohol and drugs with swimming
activities
– Do not overexert
– Avoid dangerous situations
– Buddy swim
Pitfalls
• Low oxygen saturation???
– Calls for significant monitoring – can
decompensate quickly
• Head trauma and drowning???
• Look for cervical spine trauma
• Hot water drowning
• Much quicker lethality…lower survival
Pitfalls
• Cold water drowning???
– Don’t give up quickly – longer survival
• High potassium???
– OK to stop CPR
• Septic tank drowning
– Massive bacterial contamination
Summary
Drowning Claims
> 8,000 death/year
Drowning Claims
>50,000 deaths/year
Prevention
Prevention
Prevention