TBI Patients Keep Cool With Induced Normothermia

— Protocol linked to better temperature control and lower in-hospital mortality.

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WASHINGTON -- An induced normothermia/anti-shivering protocol was associated with lower in-hospital mortality and better functional outcomes, but a longer stay in the ICU for patients with traumatic brain injury (TBI), researchers reported here.

In a retrospective, case-control study, normothermia (97.5ºF-99.5ºF) was "more consistently maintained" among patients treated under the protocol versus control patients (53% versus 39%, P= 0.0009), according to of Tufts Medical Center in Boston, and colleagues.

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However, the proportion of intracranial pressure (over 20 mmHg) was not significantly different, they reported in a poster at the American Academy of Neurology annual meeting.

Fevers are bad news for patients with TBI. In the past, therapeutic hypothermia has been tried to keep patients' temperatures down, but research has shown little benefit. Now, many ICUs are trying induced normothermia.

"Basically, beforehand we were using Tylenol and a cooling blanket," Green-LaRoche explained.

The employed the Arctic Sun Temperature Management System in most cases. A gel-like foam pad was wrapped around a patient's thighs and torso and linked to a computer console. Healthcare providers then chose the appropriate temperature for the patient, she said. Patients also were given acetaminophen.

The protocol calls for the administration of meperidine (Demerol) and buspirone (Buspar) to control shivering. A warming blanket is placed over patients hands and extremities to "trick the body into not shivering," Green-LaRoche said.

The study population consisted of patients with severe TBI at a Level I trauma center. They were evaluated for two, predetermined 18-month periods before introduction of the induced normothermia/anti-shivering protocol.

There were 29 cases from June 2012 to December 2013 compared with 51 controls (June 2009 to December 2010). Patients were roughly matched for gender, age, and mechanism of injury. The top three reasons for TBI were car accidents, falls, and being a pedestrian hit by a car.

There were fewer white patients in the study group versus the control group (45% versus 74%, P=0.01), and a smaller proportion of patients in the case group were transferred from outside hospitals compared with controls (15% versus 45%, P=0.006).

The authors used frequency, prevalence, Fisher's Exact Test and t-tests to weigh differences between the two groups.

The authors reported that the ICU length of stay was longer for cases (17.3 versus 12.3 days, P=0.03) but mortality was significantly lower (6.9% versus 33.3%, P=0.007).

The proportion of recorded intracranial pressures <20 mmHg was the same (85%) for the two groups. Also, the Arctic Sun was used more consistently in cases (53% versus 40%, P=0.01).

Green La-Roche identified only two study patients who died in-hospital compared with 17 patients in the control group (6.9% versus 33.3%, P=0.007).

While functional outcomes at hospital discharge were not markedly different, good outcomes -- measured with a Modified Rankin Scale score ≤2 -- were more common among the induced normothermia group, the authors reported.

Osmotic use was more prevalent in the induced normothermia group at day 1 but showed no difference at day 7. Patients in the case group were more likely to receive buspirone and meperidine, but acetaminophen use was about the same for both groups.

Study limitations included the small patient population and single-site data.

"I'd be really interested in doing a multicenter trial looking at this," Green-LaRoche told ." Hopefully, we'll get enough interest that that will happen."

One challenge with interpreting these data is determining which was more effective, the temperature management or the team approach, pointed out , professor of pediatric neurology and neurosurgery at Mattel Children's Hospital at the University of California Los Angeles.

Even just having a neurocritical care team has been shown to improve outcomes for both adults and pediatrics, stated Giza, who was not involved in the study.

However, he also noted that similar protocols have been successful in other ICUs.

"It's quite likely if they were able to parse out the normothermia part, they would see that the temperature control does have some effect," he said.

Disclosures

Green-LaRoche and co-authors disclosed no relevant relationships with industry.

Primary Source

American Academy of Neurology

Source Reference: Green-LaRoche, et al "Induced normothermia in severe traumatic brain injury patients" AAN 2015; I5-5A.