Submersion injury

Background

• Defined as respiratory impairment from submersion in liquid (regardless of pt outcome)
• No significant clinical differences between fresh-water and salt-water injuries
• No significant clinical differences between dry and wet drowning
• Epidemiology
  • Common in children <5yr, teenagers, and elderly
• Pathophysiology
  • Submersion>panic>voluntary breath holding>laryngospasm>reflex inspiration>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 pt is severly hypothermic, ventilate at half the normal rate
• C-Watch for "afterdrop" 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

• Trauma

Diagnosis

• CXR (pulm edema)
• Labs
  • CBC, Chemistry, troponin, coags, UA, total CK
• CT head/C-spine (if history of trauma)
• 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 sub-clinical status epilepticus
• Pulmonary
  • O2 to keep SaO2 >95%
  • Significant injury often requires intubation and mechanical ventilation (high PEEP)
  • If severly 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
  • Antibiotics
    • Controversial
    • Consider if concerned for pulmonary aspiration (must cover pseudomonas)
• Resuscitation
  • Length
    • Controversial
      • 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
  • Potassium
    • Value >10 mmol/dL not compatible with resuscitation in pts 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

Prognosis

• Poor prognosis associated with:
  • Prolonged submersion and resuscitation, low GCS, warm water, asystolic rhythm, male
  • Hypothermia is actually a POOR prognisticator as it indicates prolonged submersion