About This Page
This is a clinician-written, evidence-based summary aligned to the USMLE Step 2 CK Content Outline. It is intended for medical students preparing for USMLE Step 2 CK. Management reflects current ACC/AHA, USPSTF, and APA guidelines. Always cross-reference with UpToDate, institutional protocols, and clinical judgment.
The Bottom Line
- Drowning causes hypoxemia; ventilation and oxygenation are the priorities.
- Begin rescue breathing as soon as safely possible; cardiac arrest is usually secondary to hypoxia.
- Do not perform abdominal thrusts or routine attempts to remove water from lungs.
- Asymptomatic patients with normal oxygenation after observation may be discharged with precautions.
- Antibiotics and steroids are not routine after drowning; treat infection only if clinically evident.
Overview
Respiratory impairment from submersion or immersion in liquid, managed with rescue ventilation, oxygenation, rewarming, and treatment of hypoxic complications. Emergency management focuses on early recognition, stabilization, targeted investigation, and prompt definitive therapy while avoiding common pitfalls tested on USMLE Step 2 CK.
Epidemiology
This presentation is encountered in emergency and acute care settings. Risk varies by exposure, comorbidity, age, mechanism, and timeliness of treatment. Morbidity and mortality increase when recognition is delayed or when airway, breathing, circulation, antidotal therapy, or definitive source control is postponed.
Clinical Features
Symptoms
Cough, dyspnea, chest tightness, fatigue, or vomiting after submersion
Altered mental status, seizure, or loss of consciousness
Prolonged submersion, unwitnessed event, intoxication, trauma, or cold water exposure
Neck pain, headache, or neurologic deficit suggesting dive injury or trauma
Persistent cough or worsening dyspnea after initial improvement
Signs
Hypoxemia, tachypnea, increased work of breathing, wheeze, crackles, or pink frothy sputum
Hypothermia, bradycardia, or arrhythmia
Low GCS or inability to protect airway
Signs of trauma: scalp injury, cervical tenderness, focal neurologic findings
Normal exam and normal oxygenation after observation suggests low risk
Investigations
First-line
Pulse oximetry and respiratory assessmentOxygen saturation, work of breathing, auscultation, mental status, and trend over observation.
Core temperatureIdentify hypothermia; use low-reading thermometer if severe exposure is possible.
GlucoseCheck in altered mental status, seizure, pediatric cases, or unclear event.
Second-line
Chest X-rayIndicated if hypoxemia, abnormal lung exam, persistent cough, respiratory distress, or need for admission; early X-ray may be normal.
ABG/VBG and lactateFor severe respiratory distress, intubation, shock, or altered mental status.
ECGFor hypothermia, suspected arrhythmia, syncope preceding drowning, older patients, or electrolyte concerns.
Specialist
Trauma or neurologic imagingCT head/c-spine if diving injury, unexplained altered mental status, focal deficits, or high-risk mechanism.
1
Rescue and initial care
- Ensure rescuer safety and remove patient from water.
- Start rescue breathing as soon as safely possible if apneic or not breathing normally.
- Begin CPR if no pulse; use standard BLS/ACLS once on firm surface with AED/defibrillator available.
- High-flow oxygen; assist ventilation with bag-mask if inadequate breathing.
- Remove wet clothing and begin rewarming, especially after cold water exposure.
2
Emergency department management
- Treat hypoxemia with supplemental oxygen, noninvasive ventilation, or intubation depending on severity.
- Use lung-protective ventilation if ARDS develops.
- Bronchodilators for bronchospasm if present.
- Evaluate for associated trauma, intoxication, seizure, or cardiac syncope.
- Do not routinely give antibiotics or corticosteroids solely for drowning.
3
Observation and disposition
- Observe symptomatic patients until respiratory status clearly improves and oxygenation is stable.
- Admit if hypoxemia, abnormal lung exam, persistent respiratory symptoms, altered mental status, hypothermia, arrhythmia, or concerning comorbidity.
- Discharge may be appropriate after several hours if asymptomatic, normal mental status, normal oxygenation, and reliable supervision.
Complications
- Hypoxic brain injury: Most important cause of morbidity after prolonged submersion
- Aspiration pneumonitis: Chemical and inflammatory lung injury can worsen over hours
- ARDS: Severe alveolar injury and surfactant dysfunction
- Hypothermia: Cold water can cause bradyarrhythmias
- Secondary infection: Uncommon initially; risk increases with grossly contaminated water or persistent infiltrates/fever
USMLE Step 2 CK Exam Tips
- 1Drowning arrest is hypoxic — rescue breaths are crucial.
- 2Do not waste time trying to drain water from lungs.
- 3Routine prophylactic antibiotics after drowning are not recommended.
- 4CXR can be normal early; disposition depends on symptoms and oxygenation.
- 5Diving injury + neurologic symptoms = protect C-spine and image.
- 6Hypothermic drowning patient is not dead until warm and dead, but do not delay resuscitation.
practicetest your knowledge on drowningApply what you've learnt with USMLE Step 2 CK-style questions from the iatroX Q-Bank — emergency medicine and beyond.
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