Introduction
Hypothermia therapy for targeted temperature management or therapeutic hypothermia is a type of medical treatment in which there is an intentional decrease of the body temperature of the patient below the normal level of around 32 to 34 °C (Celsius) or 89.6 to 93.2 °F (Fahrenheit). Hypothermia therapy is used as a critical care treatment process in order to improve the outcome of various medical conditions like stroke, traumatic brain injury, and cardiac arrest. Hypothermia therapy decreases the metabolic rate, limiting the secondary injury caused by lack of blood flow or ischemia and restoration of blood flow or reperfusion, thereby reducing oxidative stress, inflammation, and other factors. Different methods are available to induce hypothermia, like cooling with blankets, surface cooling, cold water immersion, ice packs, or endovascular cooling.
Which Are the Medical Conditions That Benefit From Hypothermia Therapy?
Hypothermia therapy or targeted temperature management helps in improving the outcomes of various medical problems in patients like:
-
Hypothermia therapy helps in treating patients with cardiac arrest. With the reduction in the body's temperature, hypothermia therapy helps decrease the brain's damage and increase the neurological outcome.
-
Hypothermia therapy helps in decreasing the damage to the brain and will help in improving the outcome of patients having traumatic brain injury.
-
Hypothermia therapy helps reduce inflammation and other factors in stroke patients with blocked blood vessels. It helps in improving the outcome of people having stroke.
-
Hypothermia therapy is considered to be a standard treatment in the case of neonatal hypoxic-ischemic encephalopathy. It is a type of injury to the brain caused by a reduced oxygen supply and is usually seen in infants.
-
Hypothermia therapy can also help people with spinal cord injuries.
-
Hypothermia therapy can also help people with sepsis, a life-threatening problem due to infection.
What Is the Mechanism of Action of Hypothermia Therapy?
The mechanism of action of hypothermia therapy is a complex process and multi-factorial. When the temperature of the body is lower, the metabolic rate of tissues and cells is also decreased. Thus there is a reduction in the glucose and oxygen demand which will decrease the reactive oxygen species production and various other factors that help damage the tissue. Hypothermia also helps in decreasing the inflammation and cytokines release, which are part of damaging the tissue and organs. The reduced temperature will help in decreasing the release of neurotransmitters present in the brain. This helps people with traumatic brain injury or cardiac arrest. Hypothermia can also decrease blood flow and blood pressure, thereby reducing secondary injury by reperfusion or ischemia. This helps in decreasing organ dysfunction and damage.
How Is Hypothermia Induced?
Hypothermia therapy includes reducing the body temperature of the patient below the normal level of around 32 to 34 °C.
-
First, the patient is selected based on underlying medical conditions like traumatic brain injury, stroke, or cardiac arrest.
-
Then there will be the selection of cooling devices which depend on the clinical status of the patient and the severity of the condition. Some of the cooling devices used in hypothermia treatment include ice packs, cold water immersion cooling blankets, or endovascular cooling devices like intravascular catheters.
-
The temperature is monitored during the process of therapy to give the desired range of temperature. Specialized thermometers and monitoring devices are used to maintain the temperature.
-
Cooling will be initiated during the pre-hospital settings or in the hospital setting.
-
After achieving the desired body temperature range, hypothermia therapy is maintained for a specific duration of time, depending on the underlying medical condition.
-
After the maintenance period, the temperature is slowly rewarmed and carefully monitored to reduce complications like electrolyte imbalance, hypotension, and arrhythmias.
What Are the Potential Complications of Hypothermia Therapy?
The potential complications of hypothermia therapy include the following:
-
Hypothermia therapy can lead to changes in the cardiac rhythm, like atrial fibrillation, bradycardia, and ventricular arrhythmias.
-
It can lead to reduced cardiac output, thereby causing hypotension and peripheral vasoconstriction.
-
It can lead to alteration in the coagulation process, like platelet dysfunction, and can have a high risk of bleeding.
-
There can be variations in the electrolyte level, especially magnesium, and potassium, which will lead to a higher risk of arrhythmias.
-
There will be an increased chance of infection like pneumonia because of immune system suppression and longer hospitalization.
-
Shivering is commonly seen with hypothermia which will increase oxygen consumption and can interfere with the cooling process.
-
Due to the impairment in glucose metabolism, there can be hyperglycemia which will have an increased risk of infection and various other complications.
-
It can result in respiratory depression in people receiving analgesics and sedation.
-
Exposure to cold for a longer period can result in tissue and skin injury like tissue necrosis and frostbite.
What Are the Limitations of Hypothermia Therapy?
There are some limitations and challenges associated with hypothermia therapy. They include the following:
-
It is not indicated for all patients and can have an increased risk of complications.
-
It requires specialized equipment and monitoring devices.
-
It is associated with potential rust and complications if not monitored carefully.
-
The optimal timing and duration of the treatment will vary depending on the underlying medical condition.
-
Shivering is the common adverse effect of this therapy which will interfere with the warming or cooling process and will increase the consumption of oxygen.
-
There is limited data available for the long-term outcome of hypothermia treatment.
Conclusion
In conclusion, hypothermia therapy is a type of critical care intervention that helps in improving the outcomes of various medical conditions like traumatic brain injury, stroke, and cardiac arrest. It helps by reducing the body's metabolic rate, which limits secondary injury. They help in reducing inflammation and various other factors which cause tissue damage. It is generally considered a safe method and effective in reducing the temperature, but it requires careful management and monitoring to reduce and avoid potential risks and complications like electrolyte imbalance, bleeding disorders, and infections.
