Drowning is a serious and often preventable medical emergency that remains a leading cause of accidental death, particularly among children. It occurs when submersion in liquid leads to respiratory impairment, resulting in oxygen deprivation and potentially fatal complications.
While drowning is commonly associated with recreational water accidents, it presents significant clinical challenges for healthcare providers, especially respiratory therapists. These professionals play a vital role in managing airway function, optimizing ventilation, and preventing long-term complications.
Understanding the mechanisms, consequences, and treatment strategies associated with drowning is essential for improving patient outcomes and advancing respiratory care.
What Is Drowning?
Drowning is defined as a process that results in respiratory impairment from submersion or immersion in liquid. It can lead to a spectrum of outcomes ranging from mild respiratory distress to severe cardiopulmonary collapse and death. The primary mechanism of injury during drowning is asphyxia, which occurs when oxygen delivery to vital organs becomes inadequate and carbon dioxide removal is impaired.
Drowning incidents are particularly common in pediatric populations and are often associated with accidental submersion in swimming pools, lakes, or bathtubs. In adults, drowning events frequently involve alcohol or drug use hookup, which can impair judgment, coordination, and consciousness.
For every fatal drowning event, there are multiple cases of near-drowning, many of which require emergency department treatment and hospitalization. Survivors may suffer long-term neurological and pulmonary complications depending on the severity and duration of oxygen deprivation.
Pathophysiology of Drowning
The pathophysiology of drowning involves complex respiratory and cardiovascular responses triggered by water entering the airway. Two major reflex mechanisms contribute to the drowning process: airway protective reflexes and cold shock responses.
When fluid enters the airway, it irritates respiratory tissues and triggers coughing. This reflex may cause the individual to swallow or inhale water. In some cases, the airway responds with laryngospasm, which is a protective closure of the vocal cords that prevents large volumes of fluid from entering the lungs. This phenomenon is sometimes referred to as “dry drowning.” However, as oxygen deprivation worsens and the victim loses consciousness, the laryngospasm typically relaxes, allowing water to enter the lungs. This stage is known as “wet drowning” and is the most common scenario encountered clinically.
Sudden immersion in cold water can also trigger a dangerous physiologic response known as the cold shock reflex. Exposure to water temperatures below approximately 25°C can cause involuntary gasping, hyperventilation, and rapid shallow breathing. Additionally, cold water immersion leads to peripheral vasoconstriction, which increases systemic vascular resistance and places significant strain on the heart. This sudden cardiovascular stress can result in cardiac collapse, especially in vulnerable individuals.
Differences Between Freshwater and Saltwater Drowning
Although the ultimate outcome of drowning is oxygen deprivation, the specific physiological effects vary depending on whether freshwater or saltwater is inhaled.
Freshwater Drowning
When freshwater enters the lungs, it disrupts pulmonary surfactant, which is essential for maintaining alveolar stability. Loss of surfactant causes alveolar collapse and creates ventilation-perfusion mismatch, resulting in severe hypoxia. Freshwater is rapidly absorbed into the bloodstream through osmotic movement from the alveoli into the vascular system. This process worsens lung collapse and may contribute to pulmonary edema.
If large volumes of freshwater enter the circulation, electrolyte imbalances can occur. Dilution of blood sodium levels may lead to hyponatremia, which increases the risk of seizures, particularly in pediatric patients.
Additionally, freshwater can enter red blood cells through osmosis, causing hemolysis. The release of intracellular contents may lead to hyperkalemia, increasing the risk of life-threatening cardiac arrhythmias. Hemoglobin released during hemolysis can also contribute to acute kidney injury.
Saltwater Drowning
Saltwater has a much higher osmolarity than blood, creating a different pattern of injury. When seawater enters the lungs, it draws fluid from the bloodstream into the alveolar spaces. This leads to persistent pulmonary edema and prolonged shunting of blood away from functional alveoli, resulting in severe oxygenation impairment.
Saltwater also causes direct damage to the alveolar-capillary membrane, increasing lung inflammation and worsening respiratory failure. Systemically, the movement of fluid from the circulation into the lungs can cause hemoconcentration, hypernatremia, and reduced circulating blood volume. If untreated, these changes can result in hypovolemic shock and vascular collapse.
Note: Despite these physiological differences, clinical outcomes are often similar, and distinguishing between freshwater and saltwater drowning based solely on postmortem examination can be difficult.
Respiratory Complications Following Drowning
One of the most significant complications associated with drowning and near-drowning events is acute respiratory distress syndrome (ARDS). ARDS develops due to widespread inflammation, alveolar damage, and fluid accumulation within the lungs. Patients with ARDS experience severe hypoxemia and reduced lung compliance, making ventilation difficult.
In addition to ARDS, drowning victims frequently develop bronchospasm due to airway irritation from inhaled water and contaminants. Persistent airway closure or laryngospasm may require aggressive airway management. Aspiration of foreign material such as sand, mud, or debris is also common, particularly in shallow water drowning incidents. These materials can obstruct distal airways and intensify the inflammatory response, further worsening lung injury.
Pneumonia is another frequent complication, especially in cases involving contaminated or stagnant water. Opportunistic microorganisms inhaled during drowning events can cause infection if not promptly treated.
Respiratory Management and Treatment Strategies
The immediate management of drowning victims follows the fundamental airway, breathing, and circulation (ABC) approach. Rapid initiation of cardiopulmonary resuscitation is essential when respiratory or cardiac arrest occurs. Early restoration of oxygenation significantly improves survival and reduces the risk of permanent neurological injury.
Positioning is an important component of respiratory management. When feasible, prone positioning may improve airway clearance and enhance oxygenation, particularly in saltwater drowning cases where fluid continues to accumulate in the lungs. Prone positioning has also been shown to improve outcomes in patients with severe ARDS by promoting better ventilation-perfusion matching.
Airway clearance therapy is often necessary in drowning victims who aspirate foreign material. Solid debris such as sand or mud can block the airways and promote inflammatory lung injury. Upper airway clearance should be performed as soon as possible. In cases where debris reaches distal airways, bronchoscopy and bronchoalveolar lavage may be required to remove obstructing materials.
Mechanical ventilation is commonly required in drowning patients due to respiratory failure and ARDS. Lung-protective ventilation strategies are essential to minimize ventilator-induced lung injury. These strategies typically include low tidal volume ventilation, appropriate positive end-expiratory pressure (PEEP), and careful monitoring of oxygenation and ventilation parameters.
Bronchodilator therapy may be needed to treat bronchospasm resulting from airway irritation. Additionally, drowning in natural bodies of water often introduces pathogens into the respiratory system, increasing the risk of pneumonia. Prompt antibiotic therapy is frequently necessary to prevent or treat infection.
Temperature management is another critical aspect of care. Submersion in water often causes hypothermia, which can worsen cardiovascular instability and impair metabolic processes. Active rewarming and continuous temperature monitoring are essential components of post-resuscitation care.
Relevance to Respiratory Therapists and Respiratory Care
Respiratory therapists play a central role in the management of drowning patients. Their expertise in airway management, mechanical ventilation, and gas exchange optimization makes them essential members of the multidisciplinary care team.
Respiratory therapists are responsible for performing advanced airway procedures, managing ventilator settings, and monitoring patient response to treatment. They also assist with airway clearance therapies, including suctioning, bronchoscopy preparation, and aerosolized medication delivery.
In the critical care setting, respiratory therapists help implement lung-protective ventilation strategies for patients with ARDS, which significantly improves survival rates. They also contribute to the monitoring of arterial blood gases, oxygenation status, and pulmonary mechanics to guide treatment decisions.
Beyond direct patient care, respiratory therapists play a key role in prevention and education. Public awareness campaigns about water safety, drowning prevention, and emergency response can reduce the incidence of drowning events. Respiratory therapists often provide education to patients and families regarding the risks of water-related accidents and the importance of early intervention.
Near Drowning Practice Questions
1. What is drowning?
Drowning is respiratory impairment caused by submersion or immersion in liquid.
2. Why is drowning considered a major cause of accidental pediatric death?
Children are at increased risk due to limited swimming ability, lack of supervision, and environmental exposure.
3. In adults, what factors are commonly associated with drowning incidents?
Alcohol and drug use.
4. What is the primary cause of death in drowning?
Asphyxia leading to cardiopulmonary collapse.
5. What long-term complications can occur in drowning survivors?
Brain injury ranging from mild memory problems to severe neurologic disability or vegetative state.
6. What is near drowning?
Survival after submersion with potential respiratory or neurologic injury.
7. How common are near-drowning hospital admissions compared to fatal drownings?
Near-drowning hospital admissions occur several times more frequently than fatal drownings.
8. What is the first physiologic response when fluid enters the airway during drowning?
Coughing and airway irritation.
9. What is laryngospasm and how does it relate to drowning?
Reflex closure of the vocal cords that initially prevents water from entering the lungs.
10. What is commonly referred to as “dry drowning”?
Drowning where laryngospasm limits water aspiration into the lungs.
11. Why does laryngospasm often resolve during drowning progression?
Loss of consciousness relaxes the vocal cords, allowing fluid aspiration.
12. What is “wet drowning”?
Aspiration of water into the lungs after laryngospasm resolves.
13. What temperature range of water can trigger cold shock reflexes?
Water temperatures below approximately 25°C (77°F).
14. What respiratory response occurs during cold shock?
Sudden gasping followed by rapid, shallow breathing.
15. How can cold water immersion affect cardiovascular function?
Peripheral vasoconstriction increases vascular resistance and may cause cardiovascular collapse.
16. How does freshwater aspiration affect lung function?
It washes out surfactant and promotes alveolar collapse.
17. What pulmonary abnormality commonly occurs after freshwater aspiration?
Ventilation-perfusion (V/Q) mismatch and intrapulmonary shunting.
18. How does freshwater entering the bloodstream affect blood chemistry?
It dilutes plasma and causes electrolyte imbalances.
19. What electrolyte disturbance is commonly associated with freshwater aspiration?
Hyponatremia
20. Why can severe hyponatremia be dangerous in drowning victims?
It can cause seizures and neurologic dysfunction.
21. How does freshwater aspiration affect red blood cells?
Water enters RBCs by osmosis, causing hemolysis.
22. What dangerous electrolyte imbalance can result from RBC destruction?
Hyperkalemia
23. Why can hyperkalemia be life-threatening in drowning victims?
It can trigger cardiac arrhythmias such as ventricular fibrillation.
24. What kidney complication can occur after massive hemolysis in drowning?
Acute renal failure due to hemoglobin release into the bloodstream.
25. How does saltwater aspiration affect alveoli?
It draws fluid into alveoli due to its high osmolarity, worsening pulmonary edema.
26. Why does seawater cause severe alveolar flooding?
Its high salt concentration pulls water from circulation into lung tissue.
27. How does saltwater aspiration affect gas exchange?
It causes pulmonary edema and severe hypoxemia.
28. What is neurogenic pulmonary edema in drowning?
Pulmonary fluid accumulation caused by severe hypoxia affecting the brain.
29. Can lung function recover after drowning if hypoxia is corrected quickly?
Yes, pulmonary function can recover if oxygenation is restored promptly.
30. Why is rapid rescue and resuscitation critical in drowning cases?
Early reversal of hypoxia reduces the risk of permanent brain injury and death.
31. How does inhalation of hypertonic salt water affect lung fluid balance?
It draws fluid from the bloodstream into the alveoli, worsening pulmonary edema.
32. Why does saltwater aspiration often cause prolonged pulmonary shunting?
Continuous fluid movement into alveoli maintains edema and impairs gas exchange.
33. How does saltwater damage lung tissue?
It causes direct injury to the alveolar-capillary membrane.
34. What systemic effect can occur when large volumes of salt water enter the lungs?
Loss of circulating blood volume into alveoli, leading to hypovolemia.
35. What electrolyte abnormality is commonly associated with saltwater aspiration?
Hypernatremia
36. What protein imbalance may result from severe saltwater aspiration?
Hypoalbuminemia
37. Why can saltwater drowning lead to hypovolemic shock?
Fluid shifts from circulation into the lungs reduce blood volume.
38. Can autopsy reliably distinguish freshwater from saltwater drowning?
No, definitive differentiation is typically not possible.
39. What is the priority approach in managing drowning victims?
Airway, breathing, and circulation (ABC) assessment.
40. When should cardiopulmonary resuscitation be initiated in drowning victims?
Immediately if the patient is unresponsive or pulseless.
41. Why may prone positioning be helpful in drowning management?
It promotes drainage of fluid from the airways and lungs.
42. Why is temperature monitoring essential in drowning patients?
Water immersion frequently causes hypothermia.
43. Why are drowning survivors at high risk for acute respiratory distress syndrome (ARDS)?
Water aspiration damages alveoli and disrupts surfactant function.
44. What ventilation strategy is recommended for drowning-induced ARDS?
Lung-protective ventilation following ARDS guidelines.
45. What foreign materials are commonly aspirated during drowning?
Sand, mud, and debris.
46. Why does aspiration of sand or debris worsen lung injury?
It obstructs distal airways and intensifies inflammatory responses.
47. How can aspiration of solid material be identified clinically?
Foreign material may be found in the upper airway or stomach.
48. What imaging finding suggests sand aspiration after drowning?
Hyperdense “sand bronchograms” on CT scan.
49. How should upper airway foreign material be managed in drowning patients?
Prompt airway clearance and suctioning.
50. How is foreign material removed from distal airways after intubation?
Through bronchoscopy and bronchoalveolar lavage.
51. Why do drowning victims frequently develop bronchospasm?
Water irritation causes airway inflammation and constriction.
52. How is persistent bronchospasm treated in drowning patients?
With bronchodilator therapy.
53. Why may paralysis during intubation help resolve laryngospasm?
It relaxes vocal cord closure and improves airway access.
54. Why are drowning cases in natural water sources associated with pneumonia risk?
Opportunistic microorganisms may be aspirated during submersion.
55. Why is early antibiotic therapy sometimes recommended after drowning?
To prevent pneumonia caused by inhaled environmental pathogens.
56. When is prone positioning especially beneficial after saltwater drowning?
After cardiovascular stabilization to assist fluid clearance and improve oxygenation.
57. How does prone positioning improve lung function in ARDS?
It enhances ventilation-perfusion matching and alveolar recruitment.
58. Why does saltwater aspiration lead to continuous alveolar fluid accumulation?
Osmotic forces pull additional fluid into lung tissue.
59. What is the primary respiratory complication following near drowning?
Acute respiratory distress syndrome (ARDS)
60. Why is aggressive respiratory management essential in near-drowning patients?
To prevent progressive hypoxemia, respiratory failure, and long-term lung injury.
61. What is the most common cause of mortality following near-drowning events?
Severe hypoxic brain injury.
62. How does prolonged submersion time affect neurologic outcome?
Longer submersion increases the risk of permanent brain damage.
63. Why is early oxygen therapy critical in drowning victims?
To reverse hypoxemia and limit organ damage.
64. What cardiac rhythm abnormality is commonly seen during drowning-related hypoxia?
Bradycardia followed by cardiac arrest if untreated.
65. What is the difference between dry drowning and wet drowning?
Dry drowning involves airway closure caused by laryngospasm without significant water entering the lungs, whereas wet drowning occurs when water is aspirated into the lungs, disrupting gas exchange and breathing.
66. What is the diving reflex and how does it affect drowning victims?
A reflex that slows heart rate and conserves oxygen during submersion.
67. Why should cervical spine injury be suspected in certain drowning cases?
Head or neck trauma may occur during diving accidents.
68. What role does pulse oximetry play in drowning patient assessment?
It monitors oxygen saturation and guides oxygen therapy.
69. Why are arterial blood gases useful in drowning management?
They evaluate oxygenation, ventilation, and acid-base balance.
70. What acid-base imbalance is commonly seen in drowning victims?
Metabolic and respiratory acidosis due to hypoxia and CO₂ retention.
71. Why may chest radiographs appear normal immediately after drowning?
Pulmonary injury may develop hours after aspiration.
72. What delayed pulmonary complication can occur after near drowning?
Delayed acute respiratory distress syndrome.
73. Why should drowning victims be observed even if symptoms improve?
Respiratory complications can develop several hours later.
74. What neurological symptom may indicate severe hypoxic brain injury?
Altered level of consciousness or coma.
75. Why is glucose monitoring important in drowning patients?
Hypoglycemia or hyperglycemia can worsen neurologic injury.
76. Why should electrolyte levels be monitored in drowning victims?
Water aspiration can cause significant electrolyte imbalance.
77. What respiratory therapy may help remove retained airway secretions after drowning?
Airway clearance therapy
78. Why is early intubation sometimes necessary in drowning patients?
To secure the airway and provide controlled ventilation.
79. What complication may result from aspiration of contaminated water?
Chemical pneumonitis or bacterial pneumonia.
80. Why is suctioning important during initial airway management of drowning victims?
To remove fluid, debris, and secretions from the airway.
81. What cardiovascular complication can occur during severe drowning?
Hypotension due to hypoxia and fluid shifts.
82. Why is fluid resuscitation sometimes required in drowning patients?
To treat hypovolemia and maintain circulation.
83. What role does mechanical ventilation play in drowning management?
It supports oxygenation and ventilation during lung injury.
84. Why may PEEP be beneficial in drowning-related ARDS?
It helps maintain alveolar recruitment and improve oxygenation.
85. What is a common complication of prolonged mechanical ventilation in drowning patients?
Ventilator-associated pneumonia
86. Why are drowning victims at risk for secondary infections?
Aspiration introduces microorganisms into the lungs.
87. What neurologic test is often used to evaluate drowning-related brain injury?
Computed tomography (CT) or magnetic resonance imaging (MRI).
88. Why is rapid transport to advanced medical care important in drowning cases?
Early treatment improves survival and neurologic outcomes.
89. What sign may indicate severe respiratory failure in drowning patients?
Increasing carbon dioxide retention and worsening hypoxemia.
90. Why should drowning victims be monitored for multi-organ dysfunction?
Severe hypoxia can damage multiple organ systems simultaneously.
91. Why is continuous cardiac monitoring recommended for drowning patients?
Because hypoxia and electrolyte imbalances increase the risk of life-threatening arrhythmias.
92. What respiratory complication can develop from aspiration of chemical contaminants during drowning?
Chemical pneumonitis causing lung inflammation and impaired gas exchange.
93. Why may bronchodilators be used in drowning patients?
To relieve airway irritation and bronchospasm caused by aspirated water.
94. What neurologic reflex may be absent in severe drowning victims and indicates poor prognosis?
Loss of pupillary and brainstem reflexes.
95. Why is early neurological assessment important after resuscitation from drowning?
To evaluate the extent of hypoxic brain injury and guide treatment decisions.
96. What complication can occur if gastric contents are aspirated during drowning?
Aspiration pneumonia and chemical lung injury.
97. Why is frequent reassessment of respiratory status important in drowning patients?
Pulmonary injury can worsen over time despite initial stabilization.
98. How can prolonged hypoxia during drowning affect cardiac function?
It can lead to myocardial ischemia and reduced cardiac output.
99. Why should warmed intravenous fluids sometimes be administered to drowning victims?
To help correct hypothermia and improve hemodynamic stability.
100. What is the primary goal of post-resuscitation care in drowning patients?
To restore oxygen delivery, protect brain function, and prevent secondary complications.
Final Thoughts
Drowning remains a significant global health concern that poses serious respiratory and neurological risks. The primary cause of injury in drowning is oxygen deprivation, which can quickly lead to cardiopulmonary failure and permanent organ damage. Differences between freshwater and saltwater drowning influence the specific physiological effects but ultimately result in severe respiratory compromise.
Prompt recognition, early airway management, and evidence-based ventilatory strategies are essential for improving survival and reducing complications. Respiratory therapists play a vital role in the treatment and recovery of drowning victims through their expertise in airway management, mechanical ventilation, and pulmonary care.
By combining clinical skill, rapid intervention, and preventive education, respiratory care professionals help improve outcomes and save lives in drowning emergencies.
Written by:
John Landry is a registered respiratory therapist from Memphis, TN, and has a bachelor's degree in kinesiology. He enjoys using evidence-based research to help others breathe easier and live a healthier life.
References
- Gianfrancesco H, Sternard BT. Drowning: Clinical Management. [Updated 2025 Sep 15]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2025.