What is the role of diuretics, such as Lasix (furosemide), in the early stage of near drowning in adults in seawater of a tropical ocean?

Diuretics in Early Stage Near Drowning in Seawater

Diuretics such as furosemide are not recommended in the early management of adults with near drowning in seawater, as they may worsen outcomes by exacerbating electrolyte imbalances and potentially compromising hemodynamic stability.

Pathophysiology and Complications of Seawater Drowning

Seawater drowning presents unique challenges compared to freshwater drowning:

• Electrolyte abnormalities: Seawater aspiration can cause significant electrolyte disturbances, particularly elevated calcium, magnesium, and phosphorus levels 1
• Acute lung injury: Hypoxic bilateral pneumonitis is common, occurring in approximately 42% of cases 1
• Acute kidney injury (AKI): Near-drowning in seawater is associated with a high incidence of AKI (43% of cases), with 18% developing moderate to severe AKI 2

Management Priorities Based on Evidence

The 2020 International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care 3 emphasizes several key factors affecting survival in drowning victims:

1. Submersion duration: The most critical prognostic factor

   • Short submersion (<5-6 minutes): 87.7% good outcomes
   • Intermediate submersion (<10 minutes): 77.2% good outcomes
   • Prolonged submersion (>10 minutes): Dramatically worse outcomes

2. Primary interventions:

   • Immediate oxygenation and ventilation
   • Correction of hypoxemia
   • Supportive care

Role of Diuretics in Near Drowning

Diuretics like furosemide have specific FDA-approved indications 4:

• Edema associated with heart failure, cirrhosis, renal disease
• Adjunctive therapy in acute pulmonary edema
• When rapid onset of diuresis is desired

However, in seawater drowning:

1. Potential harms of diuretics:

   • May worsen electrolyte abnormalities that are already disturbed by seawater aspiration
   • Can compromise hemodynamic stability in patients who may already be hemodynamically unstable
   • May worsen acute kidney injury, which is common in near-drowning victims 2

2. Alternative approach:

   • The study of Dead Sea drowning victims 1 found that "forced diuresis" (likely meaning fluid administration to promote diuresis rather than diuretic administration) helped normalize electrolyte abnormalities
   • Focus on correcting hypoxemia and supporting respiratory function is paramount

Management Algorithm for Seawater Near Drowning

1. Immediate resuscitation:

   • Secure airway, breathing, circulation
   • Provide supplemental oxygen or mechanical ventilation as needed
   • Monitor oxygen saturation continuously

2. Laboratory assessment:

   • Electrolytes (particularly calcium, magnesium, phosphorus)
   • Arterial blood gases
   • Renal function tests

3. Fluid management:

   • Judicious fluid administration based on hemodynamic status
   • Avoid diuretics in early management
   • Monitor fluid status carefully

4. Respiratory support:

   • Supplemental oxygen
   • Consider mechanical ventilation for severe hypoxemia
   • Monitor for development of acute lung injury

5. Electrolyte correction:

   • Address specific electrolyte abnormalities as identified
   • Serial monitoring of electrolytes

Important Considerations and Pitfalls

• Submersion time is critical: Outcomes are significantly better with shorter submersion times 3
• Male predisposition to AKI: Men appear more susceptible to acute kidney injury following near-drowning 2
• Delayed complications: Monitor for "secondary drowning" or delayed pulmonary edema
• Avoid assumptions about prognosis: Even prolonged submersion in cold water can sometimes have favorable outcomes 5

The evidence strongly suggests that supportive care with careful attention to oxygenation, ventilation, and electrolyte management is the cornerstone of treatment for near-drowning victims, while diuretics may introduce additional risks without clear benefit in the early management phase.