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Managing Intracranial Pressure in Adults with Traumatic Brain Injury Using Hypothermic Therapy
Traumatic brain injury (TBI) is one of the main causes of disability and mortality worldwide. In the USA, instances of TBI comprise approximately 4.8 billion emergency room visits per year (Shen et al.). A severe case of TBI is characterized by the loss of consciousness for six hours or more following TBI, or 3-8 hours according to Glasgow Coma Scale (GCS). Increased intracranial pressure (ICP) is one of the many complications patients face after the injury, and it is the leading cause of death from head trauma in patients who reach the hospital alive (Shen et al.). Hypothermia has been used for managing TBIs with the aim of lowering the risk of mortality and abysmal neurologic outcomes.
This article aims to review existing evidence and evaluate the documented outcomes of prophylactic hypothermia on ICP. A literature search was conducted using PubMed, Web of Science and CIANHL databases. Only English articles and randomized control clinical trials (RCTs) held in the last ten years were included if the following criteria were met: human studies, age of the patients was nineteen and higher. After assessing 321 articles for eligibility, 315 were eliminated, and six RCTs remained to be included in the body of evidence. These six randomized control trials presented mixed outcomes. However, they all agree that prophylactic hypothermia does benefit the patient with an increased ICP and that further research should be conducted to define the benefits observed in these trials in a clinical study where ICP is the primary outcome.
Keywords: traumatic brain injury, intracranial pressure, randomized control clinical trial, prophylactic hypothermia.
Traumatic brain injuries (TBI) are regarded to be among the leading causes of death and disability worldwide (Williams, & Wood, 2010). According to Rehman, Ali, Tawil, and Yonas (2008), TBI is an intracranial injury that occurs when an external force causes damage to the brain. The condition is often classified by the mechanism of occurrence, severity, and other features such as the specific location and its impact on the brain. Available research evidence shows that several factors and issues can cause TBI. Some of the common causes include motor vehicle collisions, fall, violence, and contact sports where players are highly prone to injuries (Williams, & Wood, 2010). In other cases, the trauma can be caused by secondary events that alter the brain in one way or another. Some of the secondary causes of injuries that have been linked to the cases of TBI include alterations in cerebral blood flow or in the intracranial pressure.
The signs and symptoms of the TBIs depend on several factors like the nature of brain injury and the affected areas (Champion, Holcomb, & Young 2009). In most cases, however, unconsciousness is one of the primary signs of TBI. In the case of mild injury, the patient may be conscious or lose consciousness only for a few minutes (Champion, Holcomb, & Young 2009; Williams, & Wood, 2010). However, severe cases of TBI have been linked to long-term unconsciousness among patients. The other major signs of the condition include a headache, vomiting, lack of motor coordination, difficulties with balancing, and lightheadedness (Ponsford, Draper, & Schonberger, 2008; Rehman, Ali, Tawil, & Yonas, 2008). Some TBI patients also suffer from behavioral and mood changes, memory problems, attention deficit, changes in sleep patterns, and blurred vision. These symptoms allude to the lapses in brain function that usually occur when an individual experiences a brain injury (Rehman et al., 2008). In extreme cases, the condition can lead to death. Therefore, an effort is always made to prevent the condition and manage it as soon as possible. Some of the measures used for preventing TBIs include protective means and devices like helmets, counseling, and safety education (Rehman et al., 2008). However, when a TBI happens, the interventions include surgery, vision therapy, occupational therapy, and hypothermia therapy (Rehman et al., 2008; Urbano & Oddo, 2012).
Research shows that TBI is one of the leading causes of death and disability worldwide. Increased intracranial pressure (ICP) is the main cause of death in people who have a TBI and reach the hospital alive. Thus, the effective management of ICP remains critical to the process of treating TBI and reducing its adverse effects on patients. In the recent years, an ongoing research on measures and methods that can be used to manage ICP has been held. Hypothermia therapy has emerged as one of the potential interventions that can help managing ICP in patients with TBI. Urbano and Oddo (2012) posit that the available experimental evidence shows how the therapeutic temperature modulation, i.e. induced hypothermia, can help the doctors manage ICP and attenuate the signs and symptoms of TBI. The authors added that the hypothermia therapy could be used for managing ICP in the early stages of TBI (Urbano & Oddo, 2012). Unfortunately, there is a shortage of data and clinical evidence on the use and effectiveness of hypothermia therapy for ICP. Researchers are yet trying to provide conclusive evidence to support the hypothesis that hypothermic therapy can significantly reduce intracranial pressure following the brain injury. This article sought to address the next question, “Among the adult patients who suffer from a severe traumatic brain injury, do patients managed with hypothermic therapy demonstrate a significantly lower intracranial pressure than those not subjected to hypothermic therapy?”
An extensive systematic literature search was conducted between September 19, 2017, and October 8, 2017, to locate articles related to the research question. The search was performed within four different databases, specifically CINAHL, PubMed, Web of Science, and SCOPUS. In all the four databases, the articles found were about people receiving hypothermia therapy as an intervention for reducing intracranial pressure.
CINAHL Search Results
In the PubMed database search, the keywords “hypothermia” and “intracerebral hemorrhage” (ICH) were used to locate the relevant articles. This first attempt yielded 26 results. The second search using the terms “brain injury” and “hypothermia” gave 735 results. The search was limited to the studies that dealt with people of 19 years old and above and were published during the last ten years. The application of these filters yielded 104 results.
PubMed Search Results
In the PubMed database search, the keywords “hypothermia” and “TBI” were used to locate the relevant articles. Boolean operators “OR” and “AND” were used to expand the search process. The search yielded 300 results and was further limited to human studies that had been published in the last ten years. A total of 117 results came out. Adding another filter “participants aged 19 years and above” resulted in 41 findings. These articles were screened later to determine their suitability for the current study. Upon screening, 15 articles were excluded because they were about additional cerebrovascular conditions or measured variables that were noncongruent to the research question in this study. A second search in PubMed was done using the terms “hypothermia AND ICH,” “humans,” and “adult.” These search criteria yielded 12 articles. Further filtering was done by limiting the search to studies published within the last ten years and a minimum participants’ age of 19 years. The process yielded 3 results. However, none of these studies was used as they did not meet the criteria for inclusion in the current review.
Web of Science Search Results
A literature review search on this particular database was done using the terms “ICP,” “TBI,” and “induced hypothermia.” This first search gave 15 articles to check. Further filtering of the search by imposing the criteria of the studies being published within the last ten years and the age of 19 years and above for the participants gave the results consisting of 5 articles. A second search on the Web of Science was conducted using the terms “TBI,” “ICP,” “hypothermia,” “ICH,” and “observational study.” The search yielded 215 results. The application of filters like critical care medicine, neuroscience, and clinical neurology gave 147 results. The addition of filters yielded 2 results. Further review of these results led to their rejection as they did not meet the inclusion criteria.
SCOPUS Search Results
The literature search done on the SCOPUS database entailed using terms “ICP AND hypothermia.” This first attempt yielded 323 results. The limiting of the search to articles published within the last ten years reduced the number to 152 findings. Furthermore, filtering and limiting the search to neuroscience and nursing journals gave 25 results. The second search using the terms “#1 AND NOT #3” resulted in 245 outcomes. When the search was limited to the studies in English, the results were reduced to 235. Further filtering by limiting the search to research articles gave 133 findings. In total, the two searches in the SCOPUS databases yielded 158 results. However, 147 articles were excluded for failing to measure the variables of interest in the current systematic review. Thus, a total of 11 articles were obtained from the SCOPUS database and subjected to further review.
The current study entailed conducting a systematic literature search from September 19, 2017, to October 8, 2017, using PubMed, Web of Science and CIANHL databases. During the search process, only full-text English articles and randomized control clinical trials (RCTs) published in the last ten years were chosen to be further examined. Also, the search was limited to human studies that relied on participants who were 19 years and above. During the search, articles describing cerebrovascular conditions other than TBI were excluded as well as publications that had no mention of hypothermia effects on ICP. After assessing 321 articles for eligibility, 315 were eliminated, and six RCTs remained to be included in the body of evidence. The six selected studies presented mixed results regarding the effectiveness and efficiency of prophylactic hypothermia with regards to the management of ICP.
In all the six trails, the researchers included participants suffering from TBI in both the intervention and control group. However, the recruitment procedure, study population, and the number of participants differed from one study to the other. Andews et. Al. (2013), for instance, recruited a total of 387 participants at six different centers. However, only 386 took part in the study after the withdrawal of one person before the start of the research. Out of the 386 participants, 195 were assigned to the hypothermia therapy group while the remaining 192 received standard care. Clifton et. Al. (2011), on the other hand, observed patients with non-penetrating brain injury. The recruitment centers included University of TX Health Science Center in TX USA, the University of Calgary in Canada, University of Pittsburg, St. Louis University in MO USA, Charleston Area Medical Center in WV USA, the University of New Mexico in NM USA. While selecting the participants, the researchers excluded women with suspected pregnancy, SBP <110, DBP<60, HR >120BPM as well as those who could not be reached by the caregivers within the first two and a half hours after injury. The main goal was to come up with a study sample that could provide accurate data on the impact of hypothermia therapy on increased intracranial pressure following a case of TBI. The third study that was considered in this systematic review was the randomized controlled trial by Harris et al. (2009). This particular trial intended to explore and determine the effectiveness of the Discrete Cerebral Hypothermia system in managing and reducing ICP. To achieve this goal, the researchers recruited participants who had suffered from head injuries. The recruitment was limited to patients aged 18 years and above that had been treated for severe TBI GCS </=8. Furthermore, only patients who needed ICP monitor and Foley catheter as a part of the treatment were included. Finally, Harris et al. (2009) included individuals who could receive Discrete Cerebral HypoT cooling cap in the first 48 hours of admission to the hospital.
The three other articles also considered patients who had suffered from TBI to explore the effectiveness of hypothermia therapy in reducing and managing ICP. Lee et al. (2010) used a sample population of individuals who had suffered from brain damage and underwent a CT scan within the first 6 hours after injury to compare the effectiveness of HypoT in cerebral perfusion pressure (CPP) management. The patients who belonged to the following groups were excluded in the recruitment process: pregnant women, those with multiple injuries, and people with disabling neurological disease. Similarly, Qiu et. al. (2007) investigated the impact of therapeutic HypoT on patients suffering from severe traumatic brain injury. Like the study by Lee et al. (2010), Qiu et al. (2007) excluded pregnant women, people with multiple injuries, and those with hemorrhagic shock. The researchers went ahead to refine the recruitment process and the study sample by excluding those with previous cases of disabling neurological diseases. Zhao et al. (2011) also examined the impact of hypothermia therapy on the glucose and lactate levels among patients with non-penetrating brain injury. The study population excluded those with life-threatening injuries and people with SBP <70mHg following resuscitation.