UW Today

December 12, 2012

Intracranial pressure monitoring for traumatic brain injury questioned

UW Health Sciences/UW Medicine

UW neurosurgeon Randall Chesnut (fourth from left in back) and his brain trauma treatment study colleagues in Ecuador.UW Neurological Surgery

For patients with a traumatic brain injury, the default standard of care has just been turned on its head by a group of UW researchers working with colleagues at six hospitals in Bolivia and Ecuador.

In a study published Dec. 12 in the New England Journal of Medicine, the researchers found that intracranial pressure monitoring – the standard of care for severe traumatic brain injury – showed no significant difference than a treatment based on imaging and clinical examination.

“Within this field, this is a game changer,” said Randall Chesnut, a UW Medicine neurosurgeon at Harborview Medical Center in Seattle and principal investigator of the study. “We’ve been treating a number not a physiology.”

Watch a video with Dr. Randall Chesnut describing the study.

The study is the first international randomized controlled trial on traumatic brain injury the National Institutes of Health  has funded and is the first study of its type in Latin America. In trauma care, getting a patient’s intracranial pressure less than 20 millimeters of mercury, or mm, was the bellwether for effective treatment, even if it meant taking off a patient’s skull.

Raised intracranial pressure is a sign that both nervous system and blood vessel tissues are being compressed and could result in permanent neurologic damage or death.

“We suspect that one major issue is that 20 mm is not a magic number and that patients require a more complicated method of treatment,” said Chesnut.

Staff surround a traumatic brain injury patient at Hospital Japones in Bolivia.James Pridgeon/UW Neurological Surgery

In the randomized control trial, 324 patients over the age of 13 treated in intensive care units at four hospitals in Bolivia and two hospitals in Ecuador were randomly assigned to one of two specific protocols – intracranial pressure monitoring or imaging and clinical exam. They were evaluated by a combination of survival time, impaired consciousness, three-month and six-month functionality and six-month neuropsychological status assessed by a examiner in a blind study.

This composite measure was based on percentile performance, from zero to 100, across 21 measures of functional and cognitive status.

The results surprised researchers. The composite measure for intracranial pressure monitoring was a median of 56, compared with 53 for imaging and clinical exam.

Chesnut said this study should make clear that multimodality monitoring should be more commonplace. For patients, he said, this translates to more focused treatment, less unnecessary treatment and a shorter stay at the intensive care unit.

Improvement in traumatic brain injury management has been limited by lack of recognition of the importance of this medical issue, so this study brings new energy into what researchers call an “orphan disease.”

Around the world, traumatic brain injury has a huge impact on the quality of life.

Road accidents are a leading cause of traumatic brain injury worldwide, especially where safety standards, such as passenger restraints, are not enforced.UW Neurological Surgery

Traumatic brain injury is the leading cause of death among young people age 15 to 29, according to the World Health Organization, and is the leading cause of death associated with road traffic crashes.

Worldwide, an estimated 1.2 million people are killed in road crashes each year and as many as 50 million are injured, according to the World Health Organization. Projections indicate that these figures will increase by about 65 percent over the next 20 years unless there is new commitment to prevention. Injuries, and specifically traumatic brain injury, are projected to be a top five killer by 2020.

The study is part of a five-year $3.2 million grant from the National Institutes of Health Fogarty International Center and the National Institute on Neurologic Diseases and Stroke to evaluate overall outcomes. The aim of the study is  to understand the care traumatic brain injury patients receive and how this care affects outcomes. Chesnut said the idea for the study came from Bolivian intensive care specialists who weren’t sure that, if they had the money, they should spend it on costly monitors (upwards of $700 each). Since many Latin American countries do not routinely use intracranial pressure monitors, the study was conducted in Bolivia and Ecuador.

The intensive care unit at Hospital Luis Vernanza in Ecuador, one of the six study sites.Kelley Chaddock/UW Neurological Surgery.

The study grew from a core of physicians in Latin America who wanted to help survivors of traumatic brain injuries, but were hindered by lack of scientific evidence on how to treat these patients. The physicians formed the Latin Brain Injury Consortium and have teamed with Chesnut and his colleagues to look for answers.

In other findings, researchers came across what they called orphan patients – meaning the patients were not treated in an intensive care unit because no bed was available. In Latin America, due to ethical considerations, patients are treated first-come, first-served. Patients are not triaged and hospital beds are not allocated according to the severity of a patient’s condition.

The next phase of research will include setting standards for treating traumatic brain injury patients, testing the protocol based on a consensus, and then retesting it, said Chesnut.