What is the immediate treatment for hypothermia after cold water submersion?

Immediate Treatment for Hypothermia After Cold Water Submersion

Remove the victim from the water immediately, begin CPR if unresponsive with no normal breathing, and start passive rewarming by removing wet clothing and insulating the victim while activating EMS—do not delay resuscitation to check temperature or wait for rewarming. 1

Initial Rescue and Resuscitation

Immediate Actions Upon Rescue

• Remove the victim rapidly and safely from the water without placing yourself in danger. 1
• If trained, you may start rescue breathing while the victim is still in the water, but only if this does not delay removal from the water. 1
• Do not attempt abdominal or chest thrusts to remove water—there is no evidence that water acts as an obstructive foreign body, and these maneuvers waste critical time and can cause injury. 1

CPR Protocol for Hypothermic Victims

• If the victim is unresponsive with no normal breathing (or only gasping), start CPR immediately—do not wait to check temperature or for rewarming to begin. 1
• Healthcare providers may check for a pulse, but if no pulse is definitely felt within 10 seconds, begin chest compressions immediately. 1
• If alone, perform approximately 5 cycles (about 2 minutes) of CPR before leaving to activate EMS. 1
• If two rescuers are present, one should activate EMS immediately while the other continues CPR. 1
• Continue resuscitative efforts until the patient is evaluated by advanced care providers—hypothermic patients can survive prolonged submersion, particularly children in icy water, with intact neurological recovery. 1, 2, 3, 4

Rewarming Strategy

Passive Rewarming (First-Line for All Victims)

• Remove all wet clothing immediately to prevent further heat loss. 1, 5, 2
• Insulate or shield the victim from wind and environmental cold. 1
• Cover with dry blankets or other insulating materials. 5, 2
• Move to a warm environment as quickly as possible. 5, 2

Active Rewarming Considerations

• Avoid rough movement or handling—this can precipitate ventricular fibrillation or cardiac arrest in severely hypothermic patients. 6
• If available, ventilate with warm, humidified oxygen. 1
• In the out-of-hospital setting, passive warming should be used until active warming is available. 1
• For mild to moderate hypothermia, passive external warming and active external rewarming (warm blankets, insulation) are typically sufficient. 2
• Severe hypothermia (core temperature <28°C) with cardiac arrest may require advanced interventions including warmed intravenous fluids, heated humidified oxygen, body cavity lavage, or extracorporeal blood warming, but these are hospital-based treatments. 2, 3

Critical Pitfalls to Avoid

Do Not Delay CPR

• The most common error is delaying CPR to check temperature or attempt rewarming first—outcome depends primarily on duration of hypoxia and how promptly CPR is started. 1
• Assessments of breathing and pulse are particularly difficult in hypothermic victims because heart rate and breathing may be very slow. 1

Avoid Afterdrop and Rewarming Complications

• Be aware that unconscious, nonshivering hypothermia victims who are rescued and insulated may experience an afterdrop of 3-4°C in core temperature even after removal from cold. 6
• When treating heat stroke with cold-water immersion (a different scenario), monitor to prevent overcooling and iatrogenic hypothermia—remove from immersion when core temperature reaches 38.6°C (101.4°F). 1, 7

Transport Considerations

• Transport to hospital as soon as possible while continuing passive rewarming and CPR if needed. 1
• For severely hypothermic patients in cardiac arrest, transport to a facility with cardiopulmonary bypass capabilities, as this is the method of choice for resuscitation and rewarming. 3
• In children, emergency median sternotomy may be required for adequate cannulation during bypass. 3

Prognostic Factors

Favorable Survival Indicators

• Lower core temperatures at presentation are associated with better outcomes in cold water submersion—the lowest documented survival temperature is 16°C. 3
• Children have documented intact neurological survival following prolonged submersion in icy water. 1, 3
• Successful survival has been documented after 6.5 hours of continuous CPR in a hypothermic victim. 4

Continue Aggressive Resuscitation

• Neither base excess, pH, nor serum potassium levels are reliable prognostic factors for excluding resuscitation—survivors have been documented with base excess as low as -36.5 mmol/L and pH as low as 6.29. 3
• The duration of submersion, water temperature, and promptness of CPR initiation are the primary determinants of outcome. 1