NEAR DROWNING
Pediatric Critical Care MedicineEmory University
Children’s Healthcare of Atlanta
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Objectives• Definition• Incidence, epidemiology, causes• Prognosis• Interventions/managements• Opportunities that impact outcome
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Definition• Drowning: die within 24 hours of a submersion
incident• Near Drowning: survive at least 24 hrsafter a
submersion incident
» 2002 World Congress: all victims to be labeled as drowning
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Incidence/Epidemiology• CDC 2012 for 2005-2009 for US
– ~3,880 fatal drowning, 2X treated in ER for non-fatal drowning
– Leading cause of injury death among children 1-4 yrs, highest rate
– 2nd leading cause of all accidental deaths <14 yr (MVC 1st)
– Fatality: male>female (42.07:0.54/100,000– African-American
» 1.3X higher than Caucasian» 3.4X higher in 5-14 yo age group
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Incidence• For every 1 death
– 4 others hospitalized a– 14 seen in the ER
• incidence: holidays, weekends and warm weather
• Children <5 pools; older kids and adults in open water• Fatality: 35%; 33% with neurological
impairment; 11% severe neurologic sequelae
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CausesSalt Water 1-2%
Fresh water 98%
swimming pools: public 50%
swimming pools: private 3%
lakes, rivers, streams, storm drains 20%
bathtubs 15%
buckets of water 4%
fish tanks or pools 4%
toilets 1%
washing machines 1%
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Causes• Toddlers:
– Lapse of supervision– Afternoon/early evening-meal time– 84% with responsible supervising adults– Only 18% of cases actually witnessed
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Causes• Recreational boating
– 90% of deaths due to drowning» Vast majority are not wearing life jackets
– 1,200/yr– Small, open boats– 20% of deaths
» Too few or no floatation devices!
• Diving – 700-800/yr– 1st drive in unfamiliar water– 40-50% alcohol related
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Causes• Spas, hot tubs
– Entrapment in drains, covers
• Buckets drowning– males/>females– African-Americans>caucasians– Warm months>cold
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Causes• Epilepsy:
– 1.5-4.6 % had pre-existing seizure disorder– >5 yr, drown in bathtub, not be supervised
• Long QT syndrome:– Swimming may be a trigger for LQTS– Near drowning may be first presentation– Specific gene KVLQT1 mutation associated w/swimming
trigger & submersion
Laryngospasm
recurs
Unexpected
Submersion
Aspiration &
Laryngospasm anoxia, seizures
and death without
aspiration (10%)
Laryngospasm
aborted
aspirationof
water (90%)
Stage I(0-2 minutes)
Stage II(1-2 minutes)
Swallows
water
Stage III
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Pathophysiology• Part I
– Voluntary breath-holding– Aspiration of small amounts into larynx– Involuntary laryngospasm– Swallow large amounts– Laryngospasm abates (due to hypoxia)– Aspiration into lungs
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Pathophysiology• Part II
– Decrease in sats– Decrease in cardiac output– Intense peripheral vasoconstriction– Hypothermia– Bradycardia– Circulatory arrest, while VF rare– Extravascular fluid shifts, diuresis
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Pathophysiology• Diving reflex
– Bradycardia, apnea, vasoconstriction– Relatively quite weak in humans
» better in kids
– Occurs when the face is submerged in very cold water (<20°C)
– Extent of neurologic protection in humans due to diving reflex is likely very minimal
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Pathophysiology• Asphyxia, hypoxemia, hypercarbia, & metabolic
acidosis• Fresh water vs salt water - little difference
(except for drowning in water with very high mineral content, like the Dead Sea)
• Hypoxemia– Occlusion of airways with water & particulate debris– Changes in surfactant activity– Bronchospasm– Right-to-left shunting increased– Physiologic dead space increased
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Pathophysiology• Cardiac arrhythmias• Hypoxic encephalopathy• Renal insufficiency• Pulmonary injury• Global brain anoxia & potential diffuse cerebral
edema
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Pathophysiology – Cerebral edema
• Initial hypoxia• Post resuscitation cerebral hypoperfusion
– Increased ICP – Cytoxic cerebral edema:
» BBB remains intact: derangement in cellular metabolism resulting in inadequate functioning of the Na & K pump
– Excessive accumulation of cytosolic calcium causing cerebral arterial spasm
• Lance-Adams syndrome – with sign hypoxia– Post hypoxic (action) myoclonus, often mistaken for sz– Happens more often with coming out of sedation– Must be differentiated from myoclonic status (poor prognosis)
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Pathophysiology – Pulmonary Injury
• Aspiration as little as 1-3 cc/kg can cause significant effect on gas exchange– Increased permeability– Exudation of proteinaceous material in alveoli– Pulmonary edema– decreased compliance
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Pathophysiology – fresh vs. salt
• Both forms wash out surfactant– Damaged alveolar basement membrane pulmonary
edema, ARDS
• Theoretical changes not supported clinically– Salt water: hypertonic pulmonary edema– Fresh water: plasma hypervolemia, hyponatremia– Unless in Dead Sea
• Humans (most aspirate 3-4cc/kg) – Aspirate > 20cc/ kg before significant electrolyte
changes– Aspirate > 11cc/kg before fluid changes
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Pathophysiology• Findings at autopsy
– Wet, heavy lungs– Varying amounts of hemorrhage and edema– Disruption of alveolar walls– ~70% of victims had aspirated vomitus, sand, mud, and
aquatic vegetation– Cerebral edema and diffuse neuronal injury– Acute tubular necrosis
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Pathophysiology – Pulmonary edema
• Findings at autopsy– Wet, heavy lungs– Varying amounts of hemorrhage and edema– Disruption of alveolar walls– ~70% of victims had aspirated vomitus, sand, mud, and
aquatic vegetation– Cerebral edema and diffuse neuronal injury– Acute tubular necrosis
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Signs & Symptoms• 70% develops sxs within 7 hrs• Alertness agitation coma• Cyanosis, coughing & pink frothy sputum (pulm
edema)• Tachypnea, tachycardia• Low grade fever• Rales, rhonchi & less often wheezes• Signs of associated trauma to the head & neck
should be sought
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Prognosis• Better outcomes associated with early CPR
(bystander)• C-spine protection:• Transport
– Continue effective CPR– Establish airway– Remove wet clothes– Hospital evaluation
Labs & Tests • Min electrolyte changes• Increase WBC• Hct & HgB normal
initially– Fresh water: Hct falls due
to hemolysis– Inc. in free HgB w/o a
change in Hct
• DIC occasionally• ABG – metabolic
acidosis & hypoxemia
• EKG– Sinus tach, non spec
ST-segment & T-wave changes
– Resolved within hrs– Ominous- vent
arrhythmias, complete heart block
• CXR– May be nl initially– Patchy infiltrate– Pulm edema
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Treatment • ED eval• Admit if: CNS or respiratory symptoms• Observe for 4-6 hours if
– Submersion >1min– Cyanosis on extraction– CPR required
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Treatment: ED discharge • ED eval• Admit if: CNS or respiratory symptoms• Observe for 4-6 hours if
– Submersion >1min– Cyanosis on extraction– CPR required
Predicting Ability for ED Discharge
• Several studies support selected ED discharge• Child can safely be discharged home if at 6 hours
after ED presentation:– GCS > 13– Normal physical exam/respiratory effort– Room air pulse oximetry oxygen saturation > 95%
-Causey et al., Am J Emerg Med, 2000
ICU treatment: Respiratory• PPV• Treatment of bronchospasm• Steroids: no benefits• Bronchoscopy• Prophylactic abx: no benefits• Surfactant: no beneficial
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ICU treatment: Cardiovascular• Re-warming • CBF decrease 6-7% / ºC drop
– LOC 34ºC– Pupil dilate at 30ºC– V-fib 28ºC– EEG isoelectris 20ºC
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ICU treatment: CNS• ICP monitoring - not indicated, typically irreversible
hypoxic cellular injury• Brain CT – not indicated, unless TBI suspected• Mild hyperventilation?• Osmotherapy – not indicated• Corticosteroids (dexamethasone) - no proven benefit• Seizures - treat aggressively• Shivering or random, purposeless movements can
increase ICP• Hypothermia and barbiturate coma - highly
controversial & unlikely to benefit the patient (31 comatose kids, J Modell, NEJM 1993) -
ICU treatment: Others• Antibiotics: no benefit or prophylaxis, may
increase superinfection• Fulminant strep pneumo sepsis has been
described after severe submersion• Steroids – no demonstrated benefit
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Prognosis predictors• Poor outcomes
– Age < 3yrs– Submersion time: >10 min– Time to BLS >10 min– Serum pH: <7.0– CPR >25 min– Initial core temp <33ºC– GCS <5
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Prognosis predictors
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Prognosis predictors
• Prolonged resuscitation may increase the success of resuscitation w/o normal neurologic recovery
After 25 min of full but unsuccessful resuscitation, thin “PROGNOSIS” -
Submersion time survival Fatality
0-5 min 7/67 10%
6-9 min 5/9 56%
10-25 min 21/25 88%
>25 min 4/4 100%
Effects of near drowning• Divorce• Sibling psychosocial maladjustment• 100,000 yrs of productive life lost• $4.4 million/yr in direct health care costs• $350-450 million/yr in direct costs
– $100,000/yr to care for the neurologically impaired survivor of a near drowing
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