Are cold water near-drowning victims any different from warm water victims?
Submersion accidents which lead to unconsciousness in waters colder than 70 degrees F occur with regularity. Oxygen needs are much reduced when the body is cold, therefore a permanent brain damage from low oxygen states may not occur. A 60 minute cold water submersion victim has been fully resuscitated. Similar to the hypothermic victims above these nearly drowned individuals appear cold to touch, blue, with no respiration or evident circulation and their pupils are fixed and dilated.
What is the pathophysiology of drowning?
The principal physiologic consequence of immersion injury is prolonged low oxygen level in the blood (hypoxemia). After initial gasping, and possible aspiration, immersion stimulates hyperventilation, followed by voluntary cessation of breathing and a variable degree and duration of laryngospasm. This leads to hypoxemia. Depending upon the degree of hypoxemia and resultant acidosis, the patient may develop cardiac arrest and central nervous system (CNS) lack of blood supply (ischemia). Asphyxia leads to relaxation of the airway, which permits the lungs to fill with water in many individuals (“wet drowning”). Approximately 10-20% of individuals maintain tight laryngospasm until cardiac arrest occurs and inspiratory efforts have ceased. These victims do not aspirate any fluid (“dry drowning”).
In young children suddenly immersed in cold water, the mammalian diving reflex may occur and produce apnea,
bradycardia, and vasoconstriction of nonessential vascular beds with shunting of blood to the coronary and cerebral circulation.
The target organ of submersion injury is the lung. Injury to other systems is largely secondary to hypoxia and ischemic acidosis. Fluid aspirated into the lungs produces vagally mediated pulmonary vasoconstriction and hypertension.
Freshwater moves rapidly across the alveolar-capillary membrane into the microcirculation. Surfactant destruction occurs, producing alveolar instability, atelectasis, and decreased compliance with marked ventilation/perfusion (V/Q) mismatching. As much as 75% of blood flow may circulate through hypoventilated lungs.
In salt water near drowning, surfactant washout occurs, and rapid exudation of protein-rich fluid into the alveoli and pulmonary interstitium is observed. Compliance is reduced, direct alveolar-capillary basement membrane damage is seen, and shunting occurs. This results in rapid production of serious hypoxia. Fluid-induced bronchospasm also may contribute to hypoxia.
What are some of the factors relating to surviving cold water near-drowning?
Age of the patient – the younger the better the prognosis
Length of submersion – the shorter the better
Water temperature – the colder the better the survival
CPR – if appropriately applied the better the survival
Water Quality – the cleaner the better the survival
Struggle – the more struggle the worse the results
Other injuries – burn, blast, fractures reduce the survival
*Remember: Cold water near-drowning is more survivable than previously thought. Submersions as long as an hour can in some circumstances be fully resuscitated. Cold water may be protective to some body systems as oxygen needs are markedly reduced.
How can I recognize cold water near-drowning?
SIGNS and SYMPTOMS
1. COUGH, CLEAR TO FROTHY RED SPUTUM
2. BLUE SKIN COLOR
3. SHORTNESS OF BREATH
4. CONFUSION TO COMA
5. RESPIRATORY ARREST
6. CARDIAC ARREST
1. Remove from the water
2. Do not do a Heimlich Maneuver, as it may induce vomiting and aspiration.
3. ABC’s of resuscitation, begin CPR if indicated.
5. Remove wet or constricting clothing, wet suits, etc.
6. Transport to the nearest medical facility, noting that if this is a diving accident a recompression chamber will be necessary. Decompression sickness or air embolism may have led to the cold water near-drowning in the first place and full resuscitation should be done inside the chamber to be successful.