Using body-cooling therapies to help those with traumatic brain injuries (TBI) is not as safe of an option for reducing brain swelling as previously thought, a new study published in the New England Journal of Medicine has found. Known as induced hypothermia, the practice involves lowering a person’s body temperature, and researchers found it actually hindered long-term recovery from a TBI while also increasing a patient’s risk of disability or death thereafter.

TBIs occur more frequently than we may know, which makes employing safe and effective treatments all the more crucial. According to the study, two million people each year are diagnosed with a TBI, usually the result of a fall or car accident; 50,000 die as a result, while 80,000 suffer from a disability.

Before the research, cooling down a person’s body to help them recover from a TBI was a common practice in intensive care units throughout parts of Europe and North America. Therapeutic hypothermia typically involves cooling a patient’s core body temperature to between 89.6 degrees and 93.2 degrees. It’s most commonly used in patients who cannot regain consciousness after cardiac arrest, despite their circulation restarting. To cool the patient’s body, they are given ice cold intravenous drips within the 10 days following their accident, along with cold water blankets or cooling pads, which are applied to the body for at least 48 hours.

These procedures, however, were completed despite little clinical research on the long-term effects of the treatment. The current international study, led by the University of Edinburgh, peers into the unexamined effects on a patient’s long-term recovery. Tracking nearly 400 cases of traumatic brain injuries and spanning 18 countries, the researchers might have debunked the belief that therapeutic hypothermia is a safe method to remove swelling in the brain.

Out of the 400 people being treated for TBI, about half was given induced hypothermia, while the other half was treated with another standard procedure. Overall, the researchers found that patients who had received induced hypothermia experienced a reduction of built up pressure in their skull following the injury. However, six months down the line, patients’ recovery seemed to be much worse when compared to patients who received standard care. Because of these results, the doctors were forced to end the trial early in order to avoid harming their patients.

The researchers plan to present their findings on Oct. 7 at the European Society of Intensive Care Medicine Annual Congress in Berlin. They will also discuss their trials at the Neurocritical Care Society annual meeting in Scottsdale, Arizona on Oct. 9.

Source: Andrews P, et al. New England Journal of Medicine. 2015.