Drowning

1
Drowning

• Jana Stockwell, MD

2
Statistics

• 1995 data
• gt1000 kids lt14 years old drown
• 60 lt4 years old
• 2000 CDC data
• 3,281 unintentional drownings in USA (adults
  kids)
• averaging 9 people/day - not including
  boating-related incidents 
• 2003 CDC data
• For every child who drowns, 3 need ED care for
  non-fatal submersion injuries
• gt40 of these children require hospitalization

3
2002 World Congress on Drowning

• Drowning process resulting in primary
  respiratory impairment from submersion/immersion
  in a liquid medium
• Regardless of survival
• Drowning without aspiration does not occur
• Terms which are out
• Dry, wet, active, silent, secondary,
  near-drowning

4
1989-1998 CDC data
5
Groups at Risk (2001 data)

• Males 78 of drownings in the United States
• Children 859 children ages 0-14 years died from
  drowning
• Drowning rates have slowly declined
• 2nd-leading cause of injury-related death for
  kids ages 1-14 years 
• African Americans age-adjusted drowning rate
  for African Americans was 1.4 X higher

(CDC 2003)
6
Morbidity Mortality

• 15 of children admitted for drowning die in the
  hospital
• As many as 20 of drowning survivors suffer
  severe, permanent neurological disability

7
Drowning modalities

• Infants (age lt1) - bathtubs, buckets toilets
• Children ages 1-4 years - swimming pools, hot
  tubs spas
• Children ages 5-14 years - swimming pools open
  water sites

(Brenner 2001)
8
Bucket drownings

• 300 children in the US since 1984
• 7-15 months of age
• 24 to 31 inches tall
• Bucket may contain water or nasty cleaning fluid

9
Tub drownings

• Approximately 10 of childhood drownings
• Typically lacking adult supervision
• Do tub seats help?

10
Bathtub seats - ?? or ??

• Not intended or marketed as safety devices
• Bathtub drowning deaths of infants aged 6-10 mo
  from 1994-1998
• 40 infant drowning deaths associated with bath
  seats
• 78 deaths not associated with bath seats
• 45 of infants in this age group use bath seats
• Data suggests seats either have no effect or they
  may provide some slight protection against
  unintentional bathtub drowning risks
• Odds ratio 0.6 95 CI 0.4-0.9

Data US Consumer Product Safety Commission
National Center for Health Statistics for US
resident infants (1994-1998)
11
Tub seat use
12
Baby swim classes

• Done to teach babies to float
• No reported drownings in class
• Several reports of hyponatremic seizures
  following class (How was school today?)
• False sense of security?

13
Pool/Spa drownings

• Most residential pool drownings are in kids lt4 yo
  
• 3,000 pool drownings require hospital ED
  treatment each year
• last seen inside the home
• missing from sight lt5 minutes
• in the care of one or both parents at the time of
  the drowning
• gt50 occur in the child's home pool
• 1/3 occur at homes of friends, neighbors or
  family
• Since 1980, 230 kids lt4 yrs in spas hot tubs

(Present 1987, Brenner 2001)
14
Cochran Review Pool fencing

• Meta analysis of casecontrol studies evaluating
  pool fencing
• Results
• Pool fencing significantly reduces the risk of
  drowning
• Odds ratio (OR) for the risk of drowning or near
  drowning in a fenced pool compared to an unfenced
  pool is 0.27 (95 CI 0.16 0.47)
• Isolation fencing (enclosing pool only) is
  superior to perimeter fencing (enclosing property
  and pool)
• OR for the risk of drowning in a pool with
  isolation fencing compared to a pool with three
  sided fencing is 0.17 (95 CI 0.07 0.44).
• In-ground swimming pools without complete 4-sided
  isolation fencing are 60 more likely to be
  involved in drownings than those with 4-sided
  isolation fencing

15
Boat-related drownings

• 2002 Coast Guard data, all ages
• 5,705 boating incidents 4,062 injured, 750
  killed
• 70 of fatalities due to drowning
• 30 of fatalities due to trauma, hypothermia, CO
  poisoning, or other causes
• Alcohol was involved in 39 of fatalities
• Open motor boats - 41
• Personal watercraft 28

16
Alcohol

• Involved in 25-50 of teen and adult deaths
  associated with water recreation (Howland 1995
  Howland Hingson 1988)
• Alcohol influences balance, coordination, and
  judgment, and its effects are heightened by sun
  exposure and heat (Smith and Kraus 1988)
• Relative risk of drowning was 31.8 in persons
  with a markedly elevated alcohol level (gt21.7
  mmol/L) and 4.6 for levels lt21.6 mmol/L
  (Cummmings JAMA 2812198, 1999)

17
The event, part 1

• Voluntary breath-holding
• Aspiration of small amounts into larynx
• Involuntary laryngospasm
• Swallow large amounts
• Laryngospasm abates (due to hypoxia)
• Aspiration into lungs

18
The event, part 2

• Decrease in sats
• Decrease in cardiac output
• Intense peripheral vasoconstriction
• Hypothermia
• Bradycardia
• Circulatory arrest, while VF rare
• Extravascular fluid shifts, diuresis

19
Diving reflex

• Bradycardia, apnea, vasoconstriction
• Relatively quite weak in humans
• better in kids
• Occurs when the face is submerged in very cold
  water (lt20C)
• Extent of neurologic protection in humans due to
  diving reflex is likely very minimal

20
Pathogenesis 1

• 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

21
Pathogenesis 2

• Cardiac arrhythmias
• Hypoxic encephalopathy
• Renal insufficiency
• Global brain anoxia potential diffuse cerebral
  edema

22
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

23
Signs symptoms

• 75 of kids who develop sxs do so within 7 hours
  of event
• Coma to agitated alertness
• Cyanosis, coughing, and the production of frothy
  pink sputum
• Tachypnea, tachycardia
• Low-grade fever
• Rales, rhonchi less often wheezes
• Signs of associated trauma to the head and neck
  should be sought

24
Prevalence of concomitant traumatic injuries

• 143 drowned near-drowned kids
• Median age 3.8 years (1 mo 18.7 yrs)
• 30 with pre-existing disease
• CHD, sz, MR/CP, DD
• 5 with traumatic injuries
• All boys
• Older, mean age 13.5 years
• 6 of 7 had C-spine injury from diving

(H Shofer, Ann Emerg Med 2004)
25
Labs tests

• Very mild electrolyte changes
• Moderate leukocytosis
• Hct and Hgb usually normal initally
• Fresh water aspiration, the Hct may fall slightly
  in the first 24 hrs due to hemolysis
• Increase in free Hgb without a change in Hct is
  common
• DIC occasionally
• ABG metabolic acidosis hypoxemia

• EKG
• Sinus tachycardia nonspecific ST-segment and
  T-wave changes
• Reverts to normal within hours
• Ominous - ventricular arrhythmias, complete heart
  block
• CXR
• May be normal initially despite severe
  respiratory disturbances
• Patchy infiltrates
• Pulmonary edema

26
Therapy for the lungs

• CPAP or PEEP
• Aerosolized ß-agonists for bronchospasm
• Bronchoscopy
• Prophylactic antibiotics have not been shown to
  be beneficial
• Steroids
• No controlled human studies to support use
• Animal models and retrospective studies in humans
  have failed to demonstrate benefit

27
Surfactant

• Beneficial
• Porcine surfactant (Curosurf) 0.5 ml/kg (40
  mg/kg) IT for ARDS 8h after freshwater
  near-drowning in a 12yo (Acta Anaesthesiol Scand
  2004)

• Not beneficial
• Submerged rabbits
• (A Anker, Acad Emerg Med 1995)
• Kids
• (F Perez-Benavides, Ped Emerg Care 1995)

28
Brain therapy

• 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)

29
Bad prognostic indicators

• Submerged gt10 min
• Time till BLS gt10 min
• CPR gt25 min
• Initial GCS lt5

• Age lt3 years
• CPR in ER
• Initial ABG pH lt7.1
• Initial core temp lt33o

30
Will the child die?
31
Neurologic prognosis

• Absence of spontaneous respiration is an ominous
  sign associated with severe neurologic sequelae
• Permanent neurologic sequelae persist in 20 of
  victims who present comatose
• Minimal brain dysfunction, spastic quadriplegia,
  extrapyramidal syndromes, optic and cerebral
  atrophy, and peripheral neuromuscular damage

32
Cold vs icy water immersion

• Usually hypothermia is an unfavorable sign
• Several case reports of dramatic neurologic
  recovery after prolonged (10-150 min) icy water
  submersions
• Freezing-temperature water (lt5C)
• Core body temperature less than 28-30C, or much
  lower
• For hypothermia to be protective, core body
  temperature must fall rapidly, decreasing
  cellular metabolic rate, before significant
  hypoxemia begins

33
Hypothermia easier in kids

• High BSA/mass ratio and ? subcutaneous fat
  insulation
• Moderate hypothermia (core 32-35C) ?VO2 due to
  shivering thermogenesis increased sympathetic
  tone
• Severe hypothermia (core lt32C) shivering stops
  the cellular metabolic rate ? (7/C)

34
Hypothermia brain protection

• Effective in protecting the brain and other
  organs from anoxia for 75-110 min in controlled
  circumstances where core body temperature is
  cooled first to 18C and then the heart is
  stopped
• Deep hypothermic circulatory arrest (DHCA)
• Once cell death from hypoxemia occurs (5-6 min),
  no protective hypothermic effect or improve
  recovery

35
Hypothermia surface cooling

• Surface cooling alone is cannot ? core temp fast
  enough to yield protection
• Cooling rate in drowning victims is difficult to
  estimate as patient may also be swallowing or
  breathing in cold water
• Cardiac anesthesia literature
• Surface cooling of anesthetized naked infants
  with ice packs and ice cold water decreases
  rectal temperature by 2.5 C in the first 10
  minutes
• Another 32 minutes for the temperature to fall to
  24-26C
• During surface cooling in flowing water at 1C
  the nasopharyngeal temperature of a naked infant
  (4 kg) falls 1C every 5 minutes
• Hypothermic protection involving surface cooling
  only would seem to require submersion in icy (not
  cold) water

36
Does aspiration of icy water will accelerate the
cooling process?

• 80-90 of animals human submersion victims in
  warm or cold water drownings aspirate very little
  (lt2.2 ml/kg)
• Theoretically, a very large quantity of icy water
  would have to be aspirated or swallowed
• Immersion in icy water results in involuntary
  reflex hyperventilation and a decreased breath
  holding ability to lt10 sec, increasing the
  likelihood of aspiration and rebreathing of icy
  water in some victims

37
Ice water submersion - dogs

• Rapid violent hyperventilation lasts 70 sec
• Control animals submerged (ice water, head out of
  the water) carotid artery temp fell 0.8C in 2
  min
• Completely submerged dogs temp fell 8.0C during
  the first 2 min in both ice-water (4C)
• Rectal temp ? lagged behind ? in carotid temp
• Victims of ice-water submersions more likely to
  have involuntary breathing aspiration
• Brain may be cooled to a protective level
  (lt30C) provided the water aspirated was icy
  cardiac output lasts long enough for sufficient
  heat exchange to occur

38
Cold water submersion - humans

• Few cold water victims have significant brain
  protection
• Hypothermia is more commonly an unfavorable
  prognostic sign
• King County, WA (water is cold, but rarely icy)
• Hypothermic protection has not been observed
• 92 of good survivors had initial core temp of
  gt34C
• 61 of those who died or had severe neurologic
  injury had core temp lt34C
• Finnish study
• Median water temp 16C
• Submersion duration lt10 minutes had greatest
  sensitivity in predicting good outcome, even in
  kids

39
Re-warming

• Re-warm 1-2oC per hour to range 33-36oC
• Mild (32-35o) passive rewarming
• Moderate (28-32o)
• Shivering fails
• J wave
• Active internal/external rewarming (not
  extremities)
• Severe (lt28o)
• Appears dead, pupils dilated/NR
• VFib, extreme brady, pulseless
• Deep rectal or esophageal temps
• Maintain CPR until core temp gt32o

40
Warm water data - site

• 274 patients
• Age 6 months-15 years (mean 32 mos, median 24
  mos)
• 63 males
• Submersion witnessed in 12 cases
• Submersion site data (126 patients)
• 80 backyard pool or spa
• 11 in a bathtub
• 5 in a lake or pond
• 3 in other sites

41
Warm water data - response

• Bystander resuscitation 80 patients
• Average EMS respose time - 6.8 minutes
• Upon EMS arrival
• 76 (28) children were in cardiac arrest
• 13 (5) with PEA
• Paramedic CPR - 87/89 children
• 18 (20 of those w/ CPR) no longer needed CPR in
  ED
• Paramedics intubated 19 children
• Epinephrine in 30 patients

42
Warm water outcomes

• Cardiac
• 71 (80 of those in arrest _at_ scene) arrived to ED
  in cardiac arrest
• 13 PEA
• 5 deteriorated required CPR
• All 89 received Epi - (average duration 8.9
  minutes, range 2 to 105 minutes)
• 41 (46 of codes) survived (8 intact, 33
  vegetative)
• Longest CPR duration in an intact survivor was 47
  minutes
• Respiratory
• 125 (46) patients were intubated
• 7 were apneic, 26 were breathing but comatose

43
Warm water outcomes

• CNS
• Persistent deficits in 15 of the 185 functionally
  intact survivors
• Initial ED GCS 3 in 100 kids
• 14 survived intact
• 165 patients having GCS 4 upon arrival in the ED
• 2 survived in PVS
• all others survived intact
• 51 patients who subsequently died
• Withdrawal 22
• Brain death 23
• All intact survivors demonstrated functional
  recovery within 48 hours

44
Warm water survival in kids

• 6 studies reported functional recovery 17
  (overall average) of victims who required CPR in
  the ED
• Withholding or withdrawal of therapy from kids
  who have low probability of functional survival
  after warm water submersion injury has been
  suggested
• Failure to respond to advanced life support
  within 25 minutes
• Lack of purposeful movements or normal brain stem
  function _at_ 24 hrs
• Anecdotal experience with spectacular recoveries
  the small numbers of severely injured patients
  in most studies raises uncertainty about their
  predictive accuracy
• Graf et al. suggested that outcome for pediatric
  submersion victims can be predicted with 4
  measures coma, absence of pupillary light
  reflex, admission blood glucose concentration
  (high) and sex

45
Recommendations

• Pre-hospital resuscitation, including early
  intubation, ventilation, vascular access, and
  administration of advanced life support
  medications
• Continued resuscitation and stabilization in the
  ED
• Full supportive care in the ICU for a minimum of
  48 hrs
• Consider withdrawal of support if no neurologic
  improvement is detected after 48 hours
• Ancillary testing such as brainstem evoked
  responses, EEG, and MRI (not CT) may prove
  helpful to corroborate the neurologic examination

Pediatrics, 1997 Christenson, Jansen, Perkins
46
You cant make this stuff up

• 67 year old with pulmonary fibrosis
• S/P lung resection
• On ward, with O2
• POD2 developed distress, to ICU, intubated,
  ARDS
• Finally extubates
• (CHEST 2001 1201021-1022)

47
Part deaux a better history

• Day after extubation, RN noticed patient's friend
  attempting to submerge the patient's face in a
  water-filled basin
• On questioning, patient indicated that he was
  aspirating water to clean sinuses and lungs,
  explaining that this was a daily routine for
  cleaning airways in his family
• He noted that on POD 1, while performing this
  ritual, he had a severe coughing and choking
  spell while his face was submerged
• This "technique" was witnessed by the housestaff,
  but not reported until directly questioned

48
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