For the longest time, scientists had known that a dip in the core temperature of the body can help diminish damage caused by stress on cells and tissues of the human body. Numerous stories of unbelievable recoveries after falling into icy-cold waters have intrigued researchers. Such tales have generated interest scientists about this phenomenon.
They are now trying to see how brain cells which are deprived of oxygen during a stroke attack respond to this incident.
Cold therapy to decrease stroke damage
The race against stroke is a never ending battle. Slowly but surely, scientists have been helping stroke patients overcome this life changing event. Although the number of stroke incidents have decreased within the decade, the number of brain attacks is still alarming. In the US alone, stroke attacks had claimed 137,119 lives in 2006. It’s still the third largest cause of death after diseases of the heart and all forms of cancer. In the US, a stroke attack is still a leading cause of serious, long-term disability.
Radiant Medical, a newly formed company based in Redwood City, California is trying to tap the medically relevant potentials of this phenomenon. They are trying to harness the natural preservative powers of the icy cold water. They have now begun clinical trials to determine if lowering the body temperature of patients who had experienced a stroke attack would beneficial to these stroke patients. They are using a device which can lower the core temperature of the body to a few crucial degrees. And they are trying to see how this drop in body temperature correlates to the damage to brain cells caused by oxygen deprivation during a stroke incident.
Recent studies made have shown great potential of this occurrence. For the last six years, scientists have been studying this phenomenon on animals. Results of the studies have shown that the dip in core body temperature of animals can preserve cells of the brain after an incident of a stroke. Because of this, damaged caused by the stroke on brain tissues and on surrounding tissues have been reduced by at least fifty percent.
Researchers have found out that decreasing the body’s temperature also decreases activity within the cells of the body. The reduced temperature causes a slowing down of cellular metabolism. The slowing of cellular activity results to a decrease in the uptake and usage of oxygen and nutrients by the cells of the body. By lowering the body’s temperature, the events leading to cellular death are slowly delayed.
The risks of lowering the body’s temperature
Researchers have already tried lowering the temperature of the body. However, their method of lowering the body’s temperature was very uncomfortable for patients. They solely relied on surface cooling to induce hypothermia (lower than normal body temperature). Aside from being uncomfortable, patients began to shiver. This reflex action actually heats up the body. To counter this, scientists had to immobilize the patients and also to place them on artificial respiration. Although researchers have solved the problem of shivering, a new problem arose. Because patients were placed on a respirator and kept immobile, patients began to acquire pneumonia.
The SetPoint Device
Radiant taking into account these problems identified, had made a device which can lower the temperature of the body without the shivering. Their new device, which they named SetPoint, can reliably cool the blood supply of the body as well as eliminating the feeling of cold. They said that patients need only to be wrapped in a warming blanket and to be given a mild tranquilizer. After this, the patient will begin to feel warm throughout the procedure.
SetPoint is formed from a heat exchange catheter and a cassette with a control unit. The control unit of SetPoint regulates the temperature of the sterile saline solution which is circulating through the cassette and the catheter.
The device is introduced into the body surgically. Using the femoral vein located in the stroke patient’s thigh, the catheter is guided into the blood vessels of the stroke victim. The catheter is maneuvered until it reaches a vein near the stroke patient’s heart. Mike Dineen, director of Marketing of Radiant, said that “The blood is cooled as it passes over the catheter.” He added that “The cooled blood circulates through the body and enters the head, cooling brain tissue.”
During instances of a stroke attack, SetPoint is being used to induce moderate hypothermia. Initially, the stroke victim’s body temperature is lowered to 91.4°F (33°C) for twenty four hours. After the specified time, the core temperature is slowly brought up to the normal level of 98.6°F (37 °C). Because of its unique functionality, SetPoint allows doctors to precisely control the target temperature of the body. It also helps the healthcare team to control the rate of cooling and warming of the stroke patient.
Currently, SetPoint is being tested as treatment for stroke patients. One such study is being conducted at the Cleveland Clinic Foundation. Michael DeGeorgia, head of the neurological intensive care at Cleveland Clinic, said that “Hypothermia tightens the vessels and reduces inflammation.” He added that “We hope that keeping patients cold will reduce stroke volume, giving us more time to figure out the source of the stroke.” He declared that “It also reduces the risk of hemorrhage when clot-busting drugs are administered, so there is reason to believe that using hypothermia together with the drugs will improve patients’ functional outcome.”
During instances of a stroke attack, application of the device is seen to be more beneficial immediately after the onset of the onset of the stroke. The research team said that the aim is to apply SetPoint within the first 12 hours after experiencing a stroke attack. A good number of doctors concurred with the research team. To prevent further damage, SetPoint must be used as soon as a stroke incident occurs.
After trial results are collected and found to be favorable, the next step is to deliver SetPoint at an earlier amount of time. Instead of the recommended twelve hours, the device will be used within a narrower window of time like when a stroke is only suspected. As stated by DeGeorgia, “It would be ideal if a technician would start the hypothermia process on the way to the hospital or in the emergency room.”
The device is being tapped also for other medical purposes. Aside from decreasing the amount of damage inflicted by a stroke attack, it is now being tested for use in instances of heart attacks. And because SetPoint has the ability to regulate the patient’s body temperature, it will also be tested in other healthcare situations such as general surgery and post-operative care in the near future. There are also other California based companies which have developed similar cooling devices. Innercool Therapies in San Diego and Alsius in Irvine have constructed their own cooling devices but they are focusing on controlling fever and surgical management of aneurysms.