Submersion injury

Background

• Experiencing respiratory impairment from submersion or immersion
  • No longer old classifications (near-drowning, wet, dry, active, passive) changed by WHO in 2003
• Submersion:airway below liquid’s surface
• Immersion:splashed liquid
• No significant clinical differences between fresh-water and salt-water injuries and no significant clinical differences between dry and wet drowning

Epidemiology

• 6th most common cause of accidental death in the US
• Bimodal age distribution
  • Children<5
    • Containers, pools, bathtubs
  • Males 15-25
    • Usually associated with tox
    • Beaches, rivers, lakes
  • Associated with lower SES
  • Higher incidence in southern states and in the summer

Causes/Risk Factors

• Inadequate Supervision
• Underlying Neurological Event (stroke, seizure, weakness)
• Behavioral/Developmental Disorders
• Cardiac Events
  • Long QT, MI, HOCM
• Intoxication
• Trauma

Pathophysiology

Submersion leads to panic which leads to voluntary breath holding followed by laryngospasm and then reflex inspiration which results in aspiration.

Clinical Features

History

• Important to get witness and EMS accounts
• Ask about trauma, ETOH, temperature of water, submersion time, PMH
• Important to assess for trauma and causes of syncope resulting in drowning
• Always consider non-accidental trauma

Primary Survey

• A-Intubate if not breathing or unable to protect the airway
• B-If patient is severely hypothermic, ventilate at half the normal rate
• C-Watch for "after drop" with rewarming when hypothermic
  • Peripheral vasodilation -> cool blood returning to the heart
• D-Baseline neurological exam is crucial
• E-Remove all wet clothing, observe for signs of trauma

Differential Diagnosis

Water-related injuries

• Hypothermia
• Immersion pulmonary edema
• Marine toxins, envenomations, and bites
• Scuba diving emergencies
• Submersion injury (drowning and near-drowning)

Diagnosis

• CXR (pulm edema)
• Labs
  • CBC, Chemistry, troponin, coags, UA, total CK, ABG
• CT head/C-spine (if history of trauma)
  • C-Collar/C-spine Injury extremely low without evidence or history of trauma <0.5% in large cohort study
• ECG
  • Dysrhythmias are common in hypothermia

Treatment

Neurologic

• Assume C-spine injury if unclear mechanism
• Intubate to protect airway if indicated
• Control seizures if they occur, consider subclinical status epilepticus

Pulmonary

• O2 to keep SaO2 >95%
• Significant injury often requires intubation and mechanical ventilation (high PEEP)
• If severely hypothermic, ventilate at half the normal rate

Cardiovascular

• IV fluid for volume depletion (common secondary to cold diuresis)
• Arrhythmias
  • Defibrillate with normal Joules
  • If initial defib attempt unsuccessful and temp <32, rewarm to 32 deg and reattempt
  • Rewarm with passive versus active depending on degree of hypothermia

ID

• Empiric Antibiotics
• Consider if immersion with grossly dirty water (sewage, glades...)
• Consider if concerned for pulmonary aspiration (must cover pseudomonas)

Resuscitation

• The length of resuscitation to achieve ROSC must weigh against devastating neuro injury with ROSC after prolonged resuscitation
• Recommend at least 30 min in warm water drowning, 60 min in cold water
• Longest submersion time with full recovery is 66 min, occurred in cold water with ECMO rewarming

Potassium

• Value >10 mmol/dL not compatible with resuscitation in patients with hypothermia

Disposition

• GCS >13, O2 sat >95%, normal pulm exam
  • Consider discharge after 4-6hr of obs
• GCS <13, supp O2 required, or abnormal pulm exam
  • Admit for full inpatient monitoring

Prognosis

• Poor prognosis associated with:
  • Prolonged submersion time
    • 11-25mins associated with 88% mortality rate
  • Time until BLS >10 mins
  • Resuscitation >30mins
  • Initial GCS<5
  • Age<3
  • Core Temp <33C
    • Hypothermia is actually a POOR prognisticator as it indicates prolonged submersion

See Also

• Water-related injuries
• Immersion pulmonary edema

Video

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