After Effects of Near Drowning
All patients requiring any level of resuscitation following near-drowning—even if only rescue breaths were needed—should be transported to the emergency department for evaluation and monitoring, as respiratory complications can develop or worsen in the initial hours after submersion 1.
Acute Complications (First 24-48 Hours)
Respiratory Complications (Most Common)
The lungs are the primary organ system affected after near-drowning, with hypoxemia being nearly universal:
- Acute Respiratory Distress Syndrome (ARDS) and Acute Lung Injury (ALI) are the most frequent serious complications, occurring in approximately 75% of hospitalized patients 2
- At presentation, most patients (95%) have a PaO2/FiO2 ratio <300, indicating significant gas exchange impairment 2
- Patients may present with rales, foamy secretions, and progressive respiratory distress 3
- Even patients with minimal initial symptoms can deteriorate within the first 4-6 hours
Management approach:
- High-concentration oxygen is the cornerstone of treatment 3
- Positive airway pressure (CPAP/BiPAP) for patients with persistent hypoxemia and increased work of breathing 3
- Intubation and mechanical ventilation reserved for severe ARDS, inability to protect airway, or refractory hypoxemia 2
- Most noncomatose patients can avoid intubation with aggressive noninvasive support 2
Neurological Complications (Most Devastating)
Anoxic encephalopathy is the most dreaded consequence and primary determinant of long-term morbidity and mortality 2:
- Results from prolonged submersion time and delayed resuscitation
- Comatose patients at presentation have significantly worse prognosis
- Neurological status at presentation is the strongest predictor of outcome
Infectious Complications
Pneumonia is a serious secondary complication that can develop after near-drowning 4:
- Occurs in approximately 10% of hospitalized patients 2
- Results in protracted hospital stays when it develops 2
- Risk factors include aspiration of contaminated water, prolonged intubation, and initial severity of lung injury
- Pathogens vary based on water source (freshwater vs. seawater) and geographic location 4
- Do not give prophylactic antibiotics—reserve antibiotics for documented infection with fever, purulent secretions, or infiltrate progression 4
Sub-Acute Complications (Days 2-7)
Respiratory Evolution
The clinical course of lung injury typically follows a predictable pattern 2:
- Rapid improvement is the rule in patients without severe neurological injury
- By day 4, approximately 77% of patients show resolution of hypoxemia 2
- Radiographic findings resolve in about 67% by day 4 2
- Mean hospital stay is 5 days for uncomplicated cases 2
Critical pitfall: Superimposed pneumonia can interrupt this expected improvement trajectory—any patient not following the typical rapid improvement pattern should be evaluated for secondary infection 2.
Renal Complications (Uncommon but Serious)
Acute kidney injury (AKI) can develop 24-48 hours post-submersion 5:
- Multifactorial etiology: ischemia-reperfusion injury, rhabdomyolysis, hemolysis
- Monitor urine output and creatinine in severely affected patients
- May require temporary hemodialysis but typically recovers with supportive care 5
- Complete renal recovery is expected in most cases 5
Recommended Management Algorithm
Minimal/No Symptoms at Presentation
- Physical examination focusing on respiratory rate, work of breathing, lung auscultation
- Pulse oximetry monitoring
- Observe for 4-6 hours before discharge 3
- No routine laboratory testing or chest X-ray needed if asymptomatic 3
Symptomatic Patients
- Arterial blood gas, complete blood count, electrolytes, blood glucose 6
- Chest radiography 6
- Continuous cardiorespiratory monitoring with pulse oximetry 6
- Serial neurological assessments
- High-flow oxygen or positive pressure ventilation as needed 3
- Admission for ongoing monitoring and supportive care
Severe Presentations (Coma, Cardiac Arrest, Severe ARDS)
- Aggressive airway management and mechanical ventilation
- ICU admission
- Avoid prophylactic antibiotics unless clear aspiration of grossly contaminated water 4
- Monitor for secondary complications (pneumonia, AKI)
- Prognosis primarily determined by neurological status 2
Special Considerations
Hypothermia management may be necessary depending on water temperature and submersion duration—use passive external rewarming for mild cases and active rewarming techniques for moderate to severe hypothermia 6.
Elderly patients (>60 years) comprise the majority of adult near-drowning victims and can still achieve good outcomes despite more severe initial presentations, provided they are not comatose 2.
The mortality rate for hospitalized, noncomatose near-drowning victims is very low (approximately 2-3%), with most deaths occurring in patients with severe anoxic brain injury 2.