Near-Drowning

Definition & Pathophysiology - Drowning Depths

• Definition (WHO): Respiratory impairment from submersion/immersion in liquid.
  • 'Near-drowning' obsolete; use 'drowning' with outcome (fatal/non-fatal).
• Epidemiology: Highest risk in toddlers (1-4 yrs) and adolescent males.
• Pathophysiology:
  • Primary Insult: Hypoxia.
  • Laryngospasm ('dry'): ~10-15%; glottic closure, no initial aspiration.
  • Aspiration ('wet'): ~85-90%; fluid in lungs.
  • Water Type:
    • Freshwater (hypotonic): Surfactant washout $\rightarrow$ atelectasis.
    • Saltwater (hypertonic): Alveolar fluid influx $\rightarrow$ edema.
    • Hypoxia is the dominant factor regardless of water type.
  • Systemic: CNS (HIBI), CVS (arrhythmias), Resp (ARDS), Renal (ATN), metabolic acidosis.

⭐ The most significant consequence of drowning is hypoxic brain injury (HIBI), determining long-term outcome.

Clinical Features & Assessment - Gasping Signs

• Spectrum: Asymptomatic to cardiorespiratory arrest.
• Respiratory: Cough, dyspnea, tachypnea, cyanosis. Crackles, wheezes, apnea.
• Neurological: Altered sensorium (GCS), seizures. Assess for Hypoxic Ischemic Brain Injury (HIBI).
• Cardiovascular: Tachycardia/bradycardia, hypotension, arrhythmias.
• Hypothermia: Common, especially in children.
• Associated injuries: Head/cervical spine trauma (diving).
• Initial Assessment: ABCDE approach.
  • Key history: Duration of submersion, water temp, type of water, bystander CPR.

⭐ Patients asymptomatic with normal oxygen saturation and lung sounds for 6-8 hours of observation are unlikely to develop significant respiratory complications.

Management - Rescue & Revive Protocol

• Pre-hospital:

  • Safe rescue from water.
  • Immediate CPR: Compressions + Breaths.
  • C-spine immobilization prn (if trauma suspected).
  • Remove wet clothes, prevent heat loss.

• ED & ICU Management:

  • Oxygenation & Ventilation:
    • Initiate high-flow O2. Consider CPAP/BiPAP for respiratory distress.
    • For ARDS: Intubation & Lung Protective Ventilation (low tidal volume, optimal PEEP). PEEP is crucial.
  • Circulation:
    • Cautious IV fluid resuscitation, guided by clinical assessment.
    • Vasopressors for persistent hypotension.
  • Hypothermia:
    • Gradual rewarming to normothermia.
    • Consider therapeutic hypothermia (32-36°C) for neuroprotection if post-cardiac arrest (note: evidence in drowning is limited).
  • Monitoring:
    • Continuous: cardiac rhythm, SpO2, ETCO2, core temperature.
    • Serial: neuro status, ABG, electrolytes, lactate.
  • Avoid:
    • NO routine prophylactic antibiotics.
    • NO routine steroids. Surfactant not routinely recommended.

⭐ Early and effective bystander CPR is one of the most important factors improving outcomes in pediatric drowning.

Prognosis & Complications - After the Splash

• Poor Prognostic Factors:
  • Submersion duration >5-10 minutes.
  • Time to effective BLS/ALS >10 minutes.
  • Severe hypothermia on admission (unless rapid cooling, preserved circulation).
  • Persistent apnea, CPR needed in ED.
  • Glasgow Coma Scale (GCS) ≤5 on presentation.
  • Severe metabolic acidosis (arterial pH <7.0-7.1).
  • Fixed and dilated pupils.
• Complications:
  • Acute Respiratory Distress Syndrome (ARDS).
  • Hypoxic-Ischemic Brain Injury (HIBI): cerebral edema, seizures, long-term neurological deficits.
  • Aspiration pneumonia.
  • Multiple Organ Dysfunction Syndrome (MODS).
  • Electrolyte imbalances (rarely severe).

⭐ The neurological status of the child after resuscitation is the most critical determinant of long-term prognosis.

High‑Yield Points - ⚡ Biggest Takeaways

• Hypoxia is the central pathophysiological event, leading to multi-organ dysfunction.
• Pulmonary complications (ARDS, surfactant inactivation, aspiration pneumonitis) are critical.
• Neurological outcome (cerebral hypoxia/edema) is the primary determinant of long-term morbidity.
• Immediate bystander CPR and early advanced airway management are crucial for survival.
• Manage hypothermia aggressively; core rewarming for temperatures <32°C.
• Prophylactic antibiotics and corticosteroids are not routinely indicated post-submersion.