Drowning

For further information, see CMDT Part 37-09: Drowning

Essentials of Diagnosis

• The first requirement of rescue is immediate rescue breathing and CPR

• Patient must also be assessed for hypothermia, hypoglycemia, concurrent injuries, and medical conditions

• Clinical manifestations are hypoxemia, pulmonary edema, and hypoventilation

General Considerations

• The World Health Organization defines drowning as the “process resulting in primary respiratory impairment from submersion in a liquid medium”

• The panel recommended previously used terms such as near-drowning, wet-drowning, dry-drowning, silent drowning be eliminated from use

• Drowning may result in asphyxiation (from fluid aspiration or laryngospasm), hypoxemia, hypothermia, and acidemia

• Outcomes from drowning range from life without morbidity to death

• Asphyxia of drowning

  • Is usually due to aspiration of fluid (previously known as “wet” drowning)

  • May result from airway obstruction caused by laryngeal spasm while victim is gasping under water (previously called “dry” drowning)

  • The primary effect is hypoxemia due to perfusion of poorly ventilated alveoli, intrapulmonary shunting, and decreased compliance

Symptoms and Signs

• Asymptomatic

• Abnormal vital signs

• Dyspnea, cough, wheezing, apnea, trismus

• Cyanosis

• Chest pain, dysrhythmia

• Hypotension

• Vomiting, diarrhea

• Headache, altered level of consciousness, neurologic deficit

• Hypothermia (from cold water or prolonged submersion)

• A pink froth from the mouth and nose indicates pulmonary edema

Differential Diagnosis

• Alcohol or drug intoxication

• Myocardial infarction

• Seizure

• Suicide attempt

• Head or spinal cord injury from diving

• Decompression sickness

Laboratory Tests

• Metabolic acidosis is common

• Arterial blood gas results may be helpful in determining the degree of injury since initial clinical findings may appear benign

• Urinalysis shows

  • Proteinuria

  • Hemoglobinuria

  • Acetonuria

• Leukocytosis is usually present

• PaO₂ is usually decreased and PaCO₂ increased or decreased

• The blood pH is decreased

• Bedside blood sugar must be checked rapidly

• Other testing is based on clinical scenario and may include

  • Serum electrolytes

  • Creatinine, estimated glomerular filtration rate

  • Lactate

  • Troponin

  • Complete blood count

  • Coagulation studies

  • Urinalysis

  • Alcohol and toxicology levels

Imaging Studies

• Chest radiographs may show pneumonitis, atelectasis, or pulmonary edema

Medications

• Bronchospasm from aspirated material may require use of bronchodilators

• Antibiotics are given only with clinical evidence of infection, not prophylactically

• Central venous pressure (or, better, pulmonary artery wedge pressure) guides use of vascular fluid replacement, pressors, diuretics

• Metabolic acidosis

  • Occurs in 70% of near-drowning victims

  • Usually corrects with adequate ventilation and oxygenation

  • Glycemic control improves outcome

Therapeutic Procedures

First aid

• Immediate CPR

• Always suspect hypothermia and associated trauma, especially brain and cervical spine injury

• Do not attempt to drain water from lungs

• Heimlich maneuver is used only if foreign body airway obstruction suspected

• Immobilize cervical spine if neck injury possible

• Do not stop basic life support for “hopeless” patients until core temperature is 32°C

  • Complete recovery has been reported after prolonged resuscitation

Hospital care

• Admit all patients

• Continuous monitoring of cardiorespiratory function, neurologic and renal and metabolic function, and urinary output

• Serial determination of arterial blood gases (ABGs), serum creatinine, and electrolytes

• Administer oxygen immediately at highest concentration and maintain oxygen saturation at ≥ 90%

• Pulmonary edema may not appear for 24 h

• Continuous positive airway pressure (CPAP) and positive end-expiratory pressure (PEEP) effectively reverse hypoxia in patients with spontaneous respirations and patent airways

• Endotracheal intubation and mechanical ventilation are indicated for patients unable to maintain open airway, adequate oxygenation or ventilation

• Nasogastric intubation to remove swallowed water and prevent aspiration

• Extracorporeal membrane oxygenation has been used in acute respiratory distress syndrome following near-drowning

• Perform serial physical examinations, chest radiographs to detect possible pneumonitis, atelectasis, pulmonary edema

• Some cases progress to irreversible CNS damage despite adequate treatment of hypoxia and shock

• Hypothermia: measure and manage core temperature as appropriate (see Hypothermia)

Prognosis

• As the duration of submersion lengthens, the probability of worse outcome increases

• Favorable prognosis is related to a duration of submersion of < 5 minutes

• Victims of near drowning who have had prolonged hypoxemia should remain under close hospital observation for 2–3 days after all supportive measures have been withdrawn and clinical and laboratory findings have been stable

• Long-term complications of near drowning may include neurologic impairment, seizure disorder, and pulmonary or cardiac damage

• A few patients may be deceptively asymptomatic during the recovery period, only to deteriorate or die as a result of acute respiratory failure within the following 12–24 h

• There is a direct correlation between prognosis and the patient's age, submersion time, rapid prehospital resuscitation and rapid transport to a medical facility, clinical status at time of arrival to hospital, Glasgow Coma Scale score, pupillary reactivity, and overall health assessment (APACHE II score)

Prevention

• Clinicians must provide patient education and guidance about drowning prevention

• Physical barriers (ie, fences) must be placed around pools and other accessible bodies of water

• Closely supervise those who cannot swim

• Avoid alcohol during recreational swimming or boating

• Swimming lessons early in life

• Use of personal flotation devices when boating or water skiing

When to Admit

• Most patients

• Inpatient monitoring includes

  • Continuous monitoring of cardiorespiratory, neurologic, renal and metabolic function

  • Maintenance of oxygenation

  • Serial determination of arterial blood gases, pH, kidney function (serum creatinine), and electrolytes

  • Measurement of urinary output

• Pulmonary edema may not appear for 24 hours