Drowning is defined by the WHO as "the process of experiencing respiratory impairment from submersion/immersion in liquid." It is the [1] third leading cause of unintentional injury death worldwide and the leading cause of injury-related death in US children aged 1–4 years. [2-3] The pathophysiology progresses from aspiration → surfactant dysfunction → noncardiogenic pulmonary edema → hypoxemia → cardiac arrest, making ventilation the cornerstone of resuscitation. [1][4]
The following classification algorithm from Szpilman et al. stratifies drowning severity into grades with associated survival percentages and guides initial management:
1. History
- Submersion duration — single most important prognostic variable; <5 min associated with favorable outcomes, >25 min invariably fatal [5]
- Water type — fresh vs. salt, pool vs. natural body of water, contaminated/polluted water; freshwater drowning independently associated with higher mortality [6]
- Water temperature — cold water (<6°C) may rarely allow prolonged submersion survival, especially in young children [7]
- Witnessed vs. unwitnessed event
- Mechanism — accidental fall, diving injury, boating accident, seizure, suicide attempt
- Preceding events — trauma, loss of consciousness, seizure, alcohol/drug use, cardiac symptoms
- Resuscitation details — bystander CPR (with ventilation?), EMS response time, duration of CPR, AED use
- Associated symptoms — cough, dyspnea, vomiting, altered mental status, chest pain
2. Alarm Features
- Cardiac arrest at scene (asystole/PEA most common rhythm) [4]
- Submersion >5–10 minutes [3][5]
- Unresponsiveness or GCS <5 on arrival [3]
- Fixed, dilated pupils [3][8]
- Persistent apnea or need for CPR in the ED [8]
- Severe hypothermia (<30°C)
- Hemodynamic instability / shock
- Signs of associated trauma — cervical spine injury (diving), head injury
- Frothy, blood-tinged sputum (massive pulmonary edema)
3. Medications
Resuscitation
- Epinephrine 1 mg IV/IO (0.01 mg/kg pediatric) for cardiac arrest — presenting rhythm is usually asystole/PEA; VF is rare [4]
- Standard ACLS/PALS medications per protocol
ED/ICU Treatment
- Bronchodilators (albuterol) for bronchospasm — first-line before considering steroids [4]
- Crystalloid bolus for hypotension not corrected by oxygenation [4]
- Vasopressors/inotropes if volume resuscitation fails — guided by echocardiography [4]
- Glucocorticoids — very limited evidence; consider only if bronchospasm refractory to bronchodilators [4]
Avoid
- Prophylactic antibiotics — not recommended; tend to select resistant organisms. Only 12% of hospitalized drowning patients develop pneumonia [4]
- Routine sodium bicarbonate — metabolic acidosis usually self-corrects with adequate ventilation [4]
- Routine diuretics — no evidence supporting use in drowning [4]
4. Diet
- NPO initially for any patient with altered mental status, respiratory distress, or potential for intubation
- Hydration — IV crystalloid as needed; no specific fluid type (salt vs. fresh water aspiration) has been shown to require different fluid management [4]
- Not a major clinical consideration in acute drowning management
5. Review of Systems
- Pulmonary — cough, dyspnea, tachypnea, hemoptysis, chest tightness
- Neurologic — headache, confusion, seizures, loss of consciousness, focal deficits
- Cardiac — palpitations, chest pain, syncope preceding event (consider arrhythmia as precipitant)
- GI — vomiting (aspiration risk), abdominal pain from swallowed water
- Musculoskeletal — neck pain, back pain (cervical spine injury from diving)
- Psychiatric — suicidal ideation (25.7% of freshwater drownings in one cohort were suicide attempts) [6]
6. Collateral History and Family History
- Witnesses — critical for estimating submersion duration, mechanism, and whether CPR was performed
- Supervision details — especially in pediatric cases (who was watching, barriers in place)
- Family history — long QT syndrome, other cardiac channelopathies, epilepsy [9]
- Psychiatric history — depression, prior suicide attempts (especially freshwater/bathtub drownings) [6]
- Social context — alcohol/drug use at time of event, swimming ability, access to pools without fencing
7. Risk Factors
- Age — bimodal: toddlers 1–4 years (highest rate) and adolescent/young adult males [3][9]
- Male sex — rates at least 2× higher than females across all ages; up to 10× in adolescents [3]
- Race/ethnicity — highest rates among American Indian/Alaska Native and Black individuals in the US [3]
- Alcohol use — implicated in 10–30% of recreational drowning deaths [9]
- Epilepsy/seizure disorder [9]
- Autism spectrum disorder [3][9]
- Cardiac arrhythmias (long QT syndrome) [9]
- Inability to swim / overestimation of swimming ability
- Lack of pool fencing or barriers [3]
- Inadequate supervision (pediatric)
- Occupational exposure — commercial fishing industry has 29× the national average fatality rate [9]
8. Differential Diagnosis
The diagnosis of drowning is typically evident from the history. The critical question is what precipitated the drowning:
- Primary drowning — accidental submersion without precipitant
- Seizure-related drowning — epilepsy is a major risk factor [9]
- Cardiac arrhythmia — long QT syndrome, Brugada, WPW, acute MI (especially in older adults/snorkelers) [9]
- Trauma — cervical spine injury (diving), head injury (boating)
- Intoxication — alcohol, drugs
- Suicide attempt — especially freshwater/bathtub drownings [6]
- Non-accidental injury — child abuse (especially infants in bathtubs)
- Hypothermia — primary hypothermia causing incapacitation vs. secondary to submersion
- Anaphylaxis — jellyfish sting or other aquatic envenomation
9. Past Medical History
- Seizure disorder / epilepsy — major precipitant
- Cardiac history — arrhythmias, channelopathies, coronary artery disease
- Autism spectrum disorder — increased drowning risk [3]
- Psychiatric history — depression, prior suicide attempts
- Substance use history
- Prior drowning events
- Neuromuscular disorders affecting swimming ability
10. Physical Exam
Vital Signs
- Tachypneahypoxemiahypothermiatachycardia or bradycardiahypotension
Focused Exam
- Airway — patency, vomitus, foreign body, frothy/blood-tinged secretions
- Lungs — rales/crackles (pulmonary edema), wheezing (bronchospasm), diminished breath sounds (atelectasis)
- Neurologic — GCS, pupillary response (fixed/dilated = poor prognosis), motor response, brainstem reflexes [3][10]
- Cardiovascular — rhythm, perfusion, signs of shock
- C-spine — tenderness, step-off (if diving/trauma mechanism)
- Skin — cyanosis, mottling, signs of trauma, core temperature
- Abdomen — distension from swallowed water
11. Lab Studies
Recommended on arrival: [4][9]
- ABG — assess hypoxemia, hypercarbia (PaCO₂ >50 mmHg may indicate need for intubation), acidosis [9]
- Blood glucose
- BMP (electrolytes, creatinine, BUN) — significant electrolyte derangements are rare [4]
- Lactate — marker of tissue hypoperfusion
Additional as indicated
- CBC — baseline; hemolysis is rare
- Troponin — if cardiac precipitant suspected
- Toxicology screen — if intoxication suspected or unexplained altered mental status [4]
- Coagulation studies — if prolonged arrest or DIC concern
- Blood type and screen — if trauma
Monitoring
- Daily sputum cultures if intubated (pneumonia develops in ~12% of hospitalized patients) [4]
- Serial ABGs to guide ventilator management
12. Imaging
First-line
- Chest X-ray — perform on arrival, though initial CXR does not correlate with ABG values, outcome, or disposition. Useful for tracking changes. Findings may include diffuse bilateral infiltrates, pulmonary edema, atelectasis [7]
- Repeat CXR if respiratory symptoms persist [9]
Additional imaging
- Head CT — if unresponsive without obvious cause, or concern for trauma. Abnormal initial CT predicts severe brain injury/death, but normal CT has no prognostic value [7]
- C-spine imaging — only if mechanism suggests injury (diving, boating, trauma); routine cervical spine immobilization is not recommended without suggestive history or exam findings [1]
Not routinely recommended
- Routine initial CXR does not change disposition in asymptomatic patients [7]
- Routine neuroimaging in awake/alert patients is not recommended [7]
13. Special Tests
Scoring Systems
- Szpilman Drowning Classification (Grades 1–6) — based on auscultation, respiratory status, and hemodynamics; correlates with survival [4]
- Submersion Score — identifies pediatric patients at low risk for injury [3]
- GCS — GCS <5 associated with poor outcome [3]
- SOFA score — independently associated with 28-day mortality in ICU patients [6]
Point-of-Care
- Pulse oximetry and capnography — immediate on arrival [9]
- Bedside echocardiography — assess cardiac function if hemodynamically unstable; early cardiac dysfunction can occur in Grade 4–6 presentations [4]
- Bedside lung ultrasound — may identify pulmonary edema, pleural effusion
Procedures
14. ECG
- Obtain on all drowning patients presenting to the ED [9]
- Most common arrest rhythm: asystole or PEA (hypoxic mechanism) [4]
- VF is rare — consider if history of coronary artery disease, epinephrine use, or severe hypothermia [4]
- Screen for precipitating arrhythmia: prolonged QTc (long QT syndrome), Brugada pattern, WPW, signs of acute MI
- Hypothermia-related findings: Osborn (J) waves, bradycardia, prolonged intervals
- Repeat ECG if persistent symptoms or rhythm changes
15. Assessment
Severity Stratification (Szpilman Classification): [4]
- Rescue/Grade 1 — no respiratory impairment or cough only with normal auscultation → 99–100% survival
- Grade 2 — rales in some lung fields → ~96% survival
- Grade 3 — acute pulmonary edema without hypotension → ~89% survival
- Grade 4 — acute pulmonary edema with hypotension/shock → ~75% survival
- Grade 5 — isolated respiratory arrest → ~56% survival
- Grade 6 — cardiac arrest → 7–12% survival
Key Prognostic Factors: [3][5][10]
- Submersion duration is the strongest predictor of outcome
- Poor prognostic indicators: submersion >10 min, GCS <5, fixed/dilated pupils, asystole, prolonged CPR (>25 min), hypothermia, need for inotropes
- No neurologic improvement at 48 hours predicts poor outcome [3]
- Most common cause of death in hospitalized drowning patients is posthypoxic encephalopathy [10]
16. Treatment Plan
Prehospital / Initial Stabilization
- CPR with rescue breathing — compression-only CPR is NOT appropriate for drowning (hypoxic mechanism) [1][11]
- Prioritize ventilation (rescue breaths, BVM, advanced airway) — oxygenation takes priority over AED in drowning [11]
- Supplemental O₂ targeting SpO₂ 92–96% [4]
- Extricate in near-horizontal position with head above body level [1]
- Routine C-spine immobilization not recommended without suggestive mechanism [1]
Emergency Department
- Grade 1: Observe, discharge if asymptomatic after observation period
- Grade 2: O₂ by face mask (15 L/min); most normalize within 6–8 hours [4]
- Grade 3–4: Early intubation with PEEP; lung-protective ventilation [4]
- Grade 5–6: Full ACLS/PALS; address hypothermia; consider ECMO for refractory cardiac arrest or severe ARDS [12]
ICU Management
- Follow ARDS ventilation guidelines — though drowning-related pulmonary injury tends to recover faster than typical ARDS [4]
- Do not wean ventilation for at least 24 hours even if P/F ratio >250 — premature weaning risks recurrent pulmonary edema [4][13]
- Target intrapulmonary shunt ≤20% or PaO₂/FiO₂ ≥250 [13]
- Vasopressors/inotropes guided by echocardiography if volume resuscitation fails [4]
- Rewarming for hypothermia — active external and/or internal rewarming as indicated
- Monitor for pneumonia (onset typically day 3–4); treat only when confirmed, not prophylactically [4]
17. Disposition
Discharge from ED
- After 4–6 hours of observation, patients with normal mental status, normal respiratory rate, no dyspnea, no need for airway support, and no hypotension may be safely discharged [7][9]
- A recent study found that patients meeting rapid discharge criteria (normal RR, SpO₂ ≥94% on room air, alert, clear auscultation, no O₂ requirement) at ED presentation required no treatment and could be considered for earlier discharge [14]
Admission Criteria
- Grade 2: Admit for observation if not normalized within 6–8 hours [4]
- Grade 3–6: ICU admission — require intubation, mechanical ventilation, or hemodynamic support [4]
- Any clinical deterioration during observation
- Concern for precipitating condition (seizure, arrhythmia, trauma, NAI)
- Suicide attempt → psychiatric evaluation
Specialist Consultation
- Pulmonology/Critical Care — for ARDS management, ECMO consideration
- Neurology — for seizure evaluation or neuroprognostication
- Cardiology — if arrhythmia suspected as precipitant
- Psychiatry — if intentional drowning/suicide attempt
- Child protective services — if non-accidental injury suspected
18. Follow Up / Return Precautions
Follow-up Timing
- PCP follow-up within 24–48 hours for all discharged patients
- Pulmonology follow-up if any respiratory symptoms persisted
Return Precautions — instruct patients/families to return immediately for:
- New or worsening cough, shortness of breath, or difficulty breathing
- Fever
- Confusion, excessive sleepiness, or behavioral changes
- Chest pain
Patient Counseling
- "Secondary drowning" and "dry drowning" are not recognized medical terms and should not be used [1]
- Delayed respiratory deterioration is rare but possible — most occurs within 4–7 hours [7]
- Discuss drowning prevention: pool fencing, supervision, swim lessons, life jacket use, avoiding alcohol near water [3]
- Most nonfatal drowning victims with good initial presentation recover fully [3]
Expected Recovery
- Patients discharged from the ED after observation generally have excellent outcomes [7]
- Pulmonary injury from drowning tends to recover faster than typical ARDS; late pulmonary sequelae are uncommon [4]
- Neurologic outcomes are determined primarily by the initial hypoxic insult — in-hospital treatment has not been demonstrated to improve neurologic outcomes beyond what is determined at the scene [3]
References
1. 2024 American Heart Association and American Academy of Pediatrics Focused Update on Special Circumstances: Resuscitation Following Drowning: An Update to the American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care. — Dezfulian C, McCallin TE, Bierens J, et al. Circulation. 2024.
2. Part 10: Adult and Pediatric Special Circumstances of Resuscitation: 2025 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care. — Cao D, Arens AM, Chow SL, et al. Circulation. 2025.
3. Prevention of Drowning. — Denny SA, Quan L, Gilchrist J, et al. Pediatrics. 2021.
4. Drowning. — Szpilman D, Bierens JJ, Handley AJ, Orlowski JP. The New England Journal of Medicine. 2012.
5. Predicting Outcome of Drowning at the Scene: A Systematic Review and Meta-Analyses. — Quan L, Bierens JJ, Lis R, et al. Resuscitation. 2016.
6. Clinical Spectrum and Risk Factors for Mortality Among Seawater and Freshwater Critically Ill Drowning Patients: A French Multicenter Study. — Reizine F, Delbove A, Dos Santos A, et al. Critical Care. 2021.
7. Wilderness Medical Society Clinical Practice Guidelines for the Treatment and Prevention of Drowning: 2024 Update. — Davis CA, Schmidt AC, Sempsrott JR, et al. Wilderness & Environmental Medicine. 2024.
8. Morbidity of Childhood Near-Drowning. — Peterson B. Pediatrics. 1977.
9. Prevention of and Emergency Response to Drowning. — Girasek DC, Hargarten S. The New England Journal of Medicine. 2022.
10. Recommended Guidelines for Uniform Reporting of Data From Drowning: The "Utstein Style". — Idris AH, Berg RA, Bierens J, et al. Circulation. 2003.
11. Resuscitation After Drowning in Children: Updated Guidelines From the AHA and AAP. — Arnold MJ. American Family Physician. 2026.
12. Rescue Strategies Combining Ultra-Protective Ventilation and Veno-Venous ECMO in a Patient With Near-Drowning-Related Severe ARDS: A Case Report and Literature Review. — Zhang L, Peng Z, Wang D, et al. BMC Anesthesiology. 2026.
13. Management for the Drowning Patient. — Szpilman D, Morgan PJ. Chest. 2021.
14. Criteria for Early Discharge of Drowning Patients From the Emergency Department. — Thom O, Roberts K, Devine S, Franklin RC. Emergency Medicine Australasia : EMA. 2025.