Water Hazards: Immersion,Submersion and Envenomation

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• Water Hazards Immersion,Submersion and
  Envenomation
• Bruce Minnes MD, FRCPC
• Staff Physician and Assistant Professor, Division
  of Paediatric Emergency Medicine
• SickKids and The University of Toronto
• bruce.minnes_at_sickkids.ca

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Disclosure

• I have no real or perceivable conflicts of
  interest in making this presentation.
• I like to eat fish.
• Bruce Minnes
• Fish are friends, not food
• Bruce the Shark

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Objectives

• Understand the epidemiology and risk factors for
  submersion injuries
• Review the pathophysiology of near-drowning
• Discuss management of victims of immersion and
  submersion injuries
• Discuss management of local marine envenomation
  injuries
• Understand the importance of primary prevention

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Immersion Terminology

• Water rescue
• Alert but experiences some distress while
  swimming
• Minimal transient symptoms
• Submersion
• Swimming related distress requiring support and
  transfer to emergency facility
• Drowning
• Death following submersion (within 24 hours)
• If death gt 24 hours drowning-related death
  submersion victim, or near drowning

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Immersion Epidemiology

• Incidence
• Peaks in early childhood and adolescence (over 50
  occur in children lt 5 years)
• Males gt females
• Second leading cause of injury-related death
• Swimming pools most common
• Also baths, buckets, garden water features

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Immersion Aetiology

• Young children
• Unable to rescue themselves
• Inflicted injury (up to 8)
• Older children
• Alcohol drugs, suicide, risk-taking, fatigue
• All ages
• Lack of skill or familiarity with aquatic
  environment
• Proximity to pools, natural bodies of water
• Seizures
• Cardiac disorder dysrhythmias
• Head and C-spine trauma
• Immersion syndrome

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Immersion Pathophysiology

• Immersion or submersion
• Loss of normal breathing pattern
• Panic, struggle, breath holding
• Laryngospasm (15) or Aspiration (85)
• Hypoxaemia

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Immersion Pathophysiology

• Hypoxaemia asphyxiation
• Major determinant of outcome
• Apnoea and bradycardia secondary to diving reflex
• Anoxia of 1-3 minutes leads to cardiac arrest
• Brain is very sensitive to hypoxia
• May be cerebral oedema 6-12 hours post successful
  resuscitation
• ARDS
• Several hours later

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Immersion Pathophysiology

• Water aspiration
• Initial laryngospasm precedes aspiration
• Minimal difference between fresh salt water
• Loss of pulmonary surfactant
• Pulmonary oedema
• Impaired alveolar capillary exchange
• Intrapulmonary shunting
• Infection only if significant bacteria in water
• Electrolyte disturbance very uncommon

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Immersion Pathophysiology

• Hypothermia
• More important in small children
• High BSA to volume ratio
• Occurs in the water during resuscitation
• Protective effect
• Cerebral
• Detrimental effect
• Dysrhythmias
• Coagulopathy
• Infection risk

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Immersion Management

• First aid
• Rescue resuscitation
• Vomiting common may aspirate
• Primary Survey
• ABC
• Secure airway/ breathing (O2, intubation)
• Protect C-spine
• Nasogastric tube to decompress stomach
• ECG monitoring/ cardiac compressions

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Immersion Management

• Hypothermia
• (Avoid exposure during initial resuscitation)
• Rewarm if ventilation oxygenation secure
• External (passive) rewarming
• Mild to moderate hypothermia (Tgt32C)
• Core (invasive) rewarming
• Severe hypothermia (Tlt32C)
• Obtunded or cardiorespiratory arrest
• Continue resuscitation until core temp gt32C

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Immersion Management

• Hypothermia
• External rewarming
• Warm blankets
• Radiant lamps
• Heating blankets
• Warm air system
• Core rewarming
• Warmed IV fluids (39C) ventilator gases (42C)
• Gastric bladder lavage (42C)
• Peritoneal lavage with K-free dialysate (42C)
• Pleural pericardial lavage
• Extracorporeal blood rewarming

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Immersion Management

• Secondary survey
• Careful examination
• C-spine injury
• Other injury
• Investigations
• Blood gas BSL
• Electrolytes
• CXR
• Think causation
• ECG
• Blood alcohol

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Immersion Management

• Pulmonary
• Oxygenation and monitoring SaO2
• Consider intubation ventilation if FiO2 gt0.5
• ?PEEP
• ?Pressure control ventilation long expiratory
  time
• ?Permissive hypercapnia
• No prophylactic antibiotics
• No diuretics (may improve gas exchange)
• No steroids
• Judicious fluid therapy
• Saline lavage if sand/particulate aspiration

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Immersion Disposition

• Admit observation ward for 6-8 hours
• Alert, healthy child
• Asymptomatic or mild transient symptoms
• Admit general ward for at least 24 hours
• Submersed gt 1 minute
• Persistent symptoms, associated trauma
• Period of apnoea, cyanosis, altered consciousness
• Concern about inflicted injury
• Admit HDU/PICU
• Any ventilatory support
• Significantly abnormal chest radiography or ABG

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Immersion Outcome

• 25-50 die (usually prior to hospital)
• Of survivors requiring full CPR
• 70 normal
• 25 mild deficit
• 5 severe deficit
• Majority of children who survive to hospital
  admission do very well

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Immersion Prognosis

• Prognostic indicators
• Immersion time
• gt8 minutes ? very low survival
• Time of 1st respiratory effort
• lt3 minutes ? good prognosis
• gt40minutes ? almost zero survival
• Core temperature
• lt33C ? better prognosis
• Persisting coma
• Extremely poor prognosis
• Arterial pH
• lt7.0 with treatment ? poor prognosis
• Arterial pO2
• lt60mmHg with treatment ? poor prognosis
• Type of water
• No bearing

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Immersion Prognosis

• Cranial computed tomographic findings in a large
  group of children with drowning Diagnostic,
  prognostic and forensic implications
• 156 patients admitted with drowning and CT within
  24 hr of admission
• Abnormal CT (initial or delayed if initial
  normal) associated with poor outcome (all GCS 3)
• KT Rafaat, et al. 2008. Pediatr Crit Care Med
  9(6)567

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Immersion Prevention

• Effect of submersion injury on water safety
  practice after the event in children, Saudi
  Arabia
• 29 patients (under 12 years)
• Mainly pools
• Water safety practices lacking (87 unsupervised)
• No pools met required safety regulations
• Event had no positive effect on water safety
  practices
• OM Hijazi, 2007. Saudi Medical Journal.
  28(1)100-4

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Immersion Prevention

• Isolation or 4-sided fencing with self-locking
  gate
• Only proven prevention strategy
• Reduces submersion incidents by 50
• Public awareness programmes
• Also probably useful
• Supervision!

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Immersion Prevention

• The Influence of Ethnicity on Aquatic
  Participation and Drowning in Canada
• New Canadians (19 per cent) are over four times
  more likely to be unable to swim than those born
  in Canada (4 per cent).
• Half (50 per cent) of new Canadians parents worry
  that their children might drown or become injured
  when swimming.
• Lifesaving Society, 2010

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Websters Falls
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Marine Envenomations
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Sea Snakes

• 9 species in Arabian Gulf
• Related to cobras
• All are extremely venomous
• Most common
• Beaked sea snake (Enhydrina schistosa)
• Yellow-bellied sea snake (Pelamus platuris)

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Sea Snake Bites

• Usually fishermen
• Mortality 3
• Venom neuro-, myo-, nephro-toxic and haemolytic
• Ach receptor blocker stimulates then blocks
  release of Ach

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Sea Snake Bites

• Onset minutes to 6 hours
• Minimal pain with bite
• Rhabdomyolysis and renal failure
• Ascending paralysis (flaccid)
• Dysphagia, trismus, ptosis
• Seizures
• Coma

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Sea Snake Bites

• Supportive care
• ? Antivenom derived from beaked sea snake

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Jellyfish

• Little mauve jellyfish

• Box or bell-shaped jellyfish

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Bluebottles
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Bluebottles

• Physalia
• Also known as Portuguese Man Of War
• Tropical and sub-tropical distribution
• Collection of zooids that act collectively as a
  single organism
• Tentacles contain thousands of nematocysts which
  fire into skin on contact
• Remain active until dried out on beach
• No fatalities in Australia
• 3 fatalities in Florida and North Carolina
• Serious envenomings in other Atlantic sp.
• Atlantic ocean species up to 30m long!

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Bluebottles

• First aid
• Remove tentacles (preferably with gloves!)
• Hot water 45C
• Denatures toxin relieves pain faster than ice
  or cold water
• Loten C, Stokes B, Worsley D et al. A randomised
  controlled trial of hot water (45C) immersion
  versus icepacks for pain relief in bluebottle
  stings. Medical Journal of Australia 2006
  184(7)329-333
• Vinegar induces firing of nematocysts
• Simple analgesia
• Attention to special areas (eg. eyes)

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Box Jellyfish

• Chironex fleckeri
• Found in tropical waters
• Potentially fatal
• 67 reported deaths in Australia (last 12 in
  children)

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Box Jellyfish

• Possible action on sodium and calcium channels
• Immediate severe pain (8 hours)
• Linear, crosshatched welts
• Death within 5 minutes
• Sudden cardiovascular collapse
• Systemic symptoms
• Hyper or hypotension
• Tachycardia and arrhythmias
• Impaired cardiac contractility
• Delayed hypersensitivity in 50
• 7-14 days later

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Box Jellyfish

• First aid
• Ice pack
• Vinegar
• Hospital
• Opioid analgesia
• Antivenom (CSL Box Jellyfish Antivenom)
• 6 ampoules in cardiac arrest
• 3 ampoules over 20 minutes in systemic envenoming
• 1 ampoule for refractory pain

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Submersion Injury and Envenomation

• Submersion leading cause of death and disability
  in children
• Little new in management
• Public Health Issue Primary Prevention of
  submersion injury
• Be prepared Know the waters and risks know
  your escape and care/first-aid strategies

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