Research Method
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IndividualResearchPaperGlasgowComaScale.doc.docxRunning Head: The Glasgow Coma Scale: Reliable and Accurate? 1
The Glasgow Coma Scale
The Glasgow Coma Scale: Reliable and Accurate?
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Research Methods in Health; Fall 2016
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Introduction
The Glasgow Coma Scale (GCS) is one of the most popular scales used to measure consciousness of patients who have suffered from some form of brain injury (Laureys, Bodart, & Gosseries, 2014). The high use of this scale is to give a physician an idea of the initial state of their patient and a general aspect of the outcome for this patient after a brain injury.
The intention of this paper is to provide brief background on the GCS on how and when it is used, and how it works. Then, the general conclusion supported by research will highlight 1) how the Glasgow Scale Score can be affected by different factors and 2) the reliability of a GCS score in predicting a patient’s outcome.
Background on Research Topic
Traumatic brain injuries (TBI) are among the most common injuries with many treatment options. These unclear courses of treatment aren’t just apparent for TBIs but for general brain injuries as well. TBIs are a result of external causes coming from outside of the body itself and classified as brain damage produced by trauma of which can affect cognitive function. The damage to the brain caused by trauma can be concentrated to a particular part of the brain, called focal damage, or can be diffuse and involving damage to many sections of the brain (National Institute of Neurological Disorders and Stroke [NINDS], 2013). The effects of a TBI can be endless, such as hematomas, infarctions, hemorrhaging, aneurysms, or strokes, for example (Wang et al., 2014). Brain injuries account for the majority of money spent on healthcare with more than $56 million dollars spent annually and affecting more than 5 million people here in the United States (NINDS, 2013). Through all the unfamiliarities that accompany TBIs, one common factor that brings together these diagnoses and treatments is the Glasgow Coma Scale.
The Glasgow Coma Scale (GCS) is a scale which assesses the level of consciousness of a brain injury patient and is used to account for the severity of the injury and predict the outcome of the patient. The GCS is the most widely used scale for brain injury patients, used in over 80 countries, and has yet to be overcome by another scale used for the same purpose (Teasdale et al., 2014). This scale is based on three parts: eyes, verbal, and motor (Teasdale, 2014). When examining the eyes, the proctor will rank the patient on eye opening from 1-4, with 1 being no eye opening, 2-opening due to pain, 3-opening due to speech, or 4-spontaneous eye opening (Teasdale et al., 2014). Verbal responses are ranked from 1-5, ranging from no sound communicated from the patient to some sounds made, words being formed, questions asked, and then the formation of full sentences (Teasdale, 2014). Motor responses are ranked from 1-6, with this ranking starting at no movement, then proceeding to involuntary movement, flexions, and all the way to obeying commands (Teasdale et al., 2014). The scores from each of these sections are then added together to equal the patient’s GCS score. This scale was intended to be used with other brain injury assessments, such as the Full Outline of UnResponsiveness (FOUR) score, and not used solely on its own; but the simplicity of this scales’ rating system and its depth of putting comatose related symptoms into the score has made it the most used by nurses, neurologists, and other health related specialists (Khanal, Bhandari, Shrestha, Acharya, & Marhatta, 2016; Teasdale et al., 2014).
Although researchers have used various study designs to evaluate the GCS, this paper primarily examines studies that have followed a prospective cohort design resulting in quantitative data.
General Conclusions from Current Research
Research has shown that the GCS may be widely used in the medical field but also that it can include factors leading to non-reliable and inaccurate scores. Studies have found that initial factors from the cause of injury could have an effect on the initial GCS score given and the overall outcome of the patient (Majdan et al., 2011). Pre-existing disorders, sickness, or disabilities could also lead to an inaccurate GCS score (Teasdale, 2014), as well as misinterpretation of the descriptions for each ranking in the three categories of the scale (Mattar, Liaw, & Chan, 2015). These misunderstandings due to misinterpretation can be caused by the vague descriptions of each ranking and the interpretations being different for each physician using this scale (Teasdale et al., 2014). Research involving the body’s natural sleep cycle along with the GCS also found that the time of day a score was given did also have an effect on the patient’s score. If the score was to be taken at night it was more likely to be lower due to the body’s natural sleep cycle lowering the patient’s consciousness level (Onita, Kirby, & Eisenhut, 2015).
Synthesized Finding #1: The Glasgow Coma Scale score can be affected by different factors
When treating a patient, active and accurate communication must be made between the physician and the patient. The GCS is used to build a bridge of communication to determine a patient’s level of consciousness. If a patient’s primary language is different from that of the physician’s, they may not be unable to successfully communicate during the ranking process resulting in an inaccurate score given. Language barriers have an impact on the accuracy of a score given due to miscommunication. A patient’s previous cognitive disability can also lead to an inaccurate score due to the lack of understanding of the physician. The patient may be deaf and not be able to hear the physician or may be blind and not able to give a correct eye ranking (Teasdale et al., 2014). As well if a patient is sedated or intubated in any form, the physician may not be able to give a clear score using the GCS model (Majdan et al., 2011; Teasdale et al., 2014). If the patient is intubated, the score for the verbal aspect of the GCS must be given of ‘not testable’ [NT] (Teasdale, 2014) and will have to be retested at a later time.
A study dealing solely with the GCS took into consideration the proctor’s knowledge of the scale and concluded it having an impact on the score given to a patient (Teasdale et al., 2014). If a proctor is not fully certain of what to report, the score could be immensely inaccurate. Research performed to understand nurses’ self-confidence in using the GCS scale found that high levels of confidence and accuracy in giving a correct score came from those who used the scale regularly. It proved that nurses who had spent a longer amount of time dealing with brain injuries during their career had the highest level of confidence in using this scale (Mattar et al., 2015).
Synthesized Finding #2: Reliability of a GCS score predicting a patient’s outcome
The Glasgow Coma Scale takes into account the patient’s initial cognitive state due to level of consciousness; with this, physicians can get an overall idea of what kind of outcome this patient may be facing (Teasdale, et al., 2014). Khanal et al. (2016) performed a study to look at the outcome predictions of the GCS score in an Intensive Care Unit (ICU) and found that there was an increase in survival of 34% with every 1 point increase of a score. This study concluded that death rates increased when the patient’s score was less than 6.5 on average, the average score for a living patient around 9.56, and the average score of 5.24 leading to death (Khanal et al., 2016). A study looking at hematomas found that when their patients had a score of 3-4, their chances of death within 30 days increased by 68.4% which is significantly higher than a 6.8% chance of death with a score of 5-12. They also found that their patients had 0% chance of death within 30 days with a score of 13-15 (Wang, et al. 2014).
A downside of the GCS scale is that it does not take into account other injuries that may have an effect on a patient’s outcome. A study looking at the outcomes of TBI patients due to different causes found that this difference can lead to bodily harm in different parts of the body other than the head causing a change in outcome thus making a patient’s GCS score irrelevant. Traffic accidents were found to be the most common cause of TBI, followed by falls (Majdan et al., 2011). The injuries induced by falls had a higher Injury Severity Score (ISS) when compared to traffic accidents and had higher results of death even though the GCS scores were almost equal in both accident cases (Majdan et al., 2011). Wang et al. (2014) found in their hematoma study that the size and shape of the hematoma can predict a patient’s 30-day mortality along with the use of a GCS score. This study concluded that for the most accurate 30-day mortality rating, the use of a GCS score, hematoma size and shape, and Intracerebral Hematoma score all together make this rating accurate.
Another undesirable result of the scale is that it does not take into account the age of patients or therapies used to increase a patient’s outcome. When treating any disease, age can have an effect on the course of treatment followed as well as the outcome. Majden et al. (2011) found that although their participants with different causes of injury had around the same GCS score, the majority of the participants who survived were around the median age of 33 compared to the median age of 56 of the majority non-survivors. This study supports the fact that older age groups have a higher chance of yielding to their injuries than younger age groups.
When looking at therapies used after a TBI to increase a patient’s outcome level, an experimental study looking at the use of Simvastatin, a drug used to decrease inflammation in the brain, showed a positive outcome rating for patients. The average GCS score of the drug receiving group was a 6.6 and the placebo group had an average GCS score of 7.6. The results of this study yielded an increase of the GCS score by 6.6 points from the statin receiving group and an increase of 3.2 points in the placebo group (Naghibi, Madani, Mazloomzadeh, & Dobakhti, 2016). Another study found that stepping, verticalization of a patient by strapping them on a machine to hold them in a standing position, a patient during their hospitalization results in a shorter ICU stay. The study found that the GCS scores measured during the stepping were higher compared to the patient’s initial score when entering the ICU but still proved to have a shorter ICU stay than those without the therapy (Frazzitta et al., 2016). These studies further validate that therapies provided to a patient can affect the patient’s outcome regardless of the patient’s initial GCS score.
Need for Further Research
There is need for further research on the Glasgow Coma Scale with the origin of the brain injury taken account for. Research conducted thus far has involved brain injury patients without categorizing them specifically by causation. Research conducted by Majden et al. (2011) involved grouping his participants in three categories of accidents: traffic, falls, and other. Motor vehicle, bicycle and motorcycle accidents were all categorized into the traffic group. What wasn’t accounted for in this study was the specific type of motor vehicle accident or cause of the accident. These differences could have a significant effect on the GCS score given to those injured.
An experimental study looking at the effects of Simvastin, a drug used for inflammation in the brain, performed research with 44 patients with the inclusion of the following criteria: the patient must be 18 years of age or older, not taking any other specific drugs, have no history of disease, and had to have had trauma only to the head. None of the inclusion criteria included how the trauma manifested (Naghibi et al., 2016). Although the GCS scores were taken of the patients in Naghibi et al. (2016) research, the different forms of trauma incurred to patients could lead to different types of treatments needed for them compared to others in the study. These different treatments could have different risks put onto the patients compared to those that may not need the same treatments. Wang et al. (2014) excluded patients suffering from previous hematomas, infarctions, hemorrhaging, aneurysms, or strokes with these all having an effect on the results found besides what was being measured.
A way to possibly fill this gap in previous research could be with a retroprospective cohort study including patients suffering from TBIs of which were caused in the same manner. TBI patients sharing the same cause of injury would lead to a decrease in possible confounders affecting the GCS score given to the patient thus ensuring reliability of the score in predicting the patient’s outcome. Similar to the study performed by Majden et al. (2011) on the severity and outcome of TBIs, this study would aim to analyze the outcomes of TBI patients and correlating them to the GCS scores given to them upon arrival and departure of treatment. Data collection would be conducted independently by ICU personnel for each patient in the locations approving of the study. The data would then be retrieved through the International Traumatic Coma Project database and the outcomes after discharge being collected by a local researcher at each location. The use of the SPSS version 17 for statistical analyses proves favorable from past research and P<0.05. The use of receiver operating characteristics (ROC) would test for variance in GCS scores given. All of these data collection and analyses methods were previously approved for past research (Frazzitta et al., 2016; Khanal et al., 2016; Majdan et al., 2011; Naghibi et al., 2016).
A sample size of no less than 20 patients per specific cause and form of accident would be required to show power within the study. This sample size relates to the sample sizes used in Naghibi et al. (2016) study on Simvastin and Frazzitta et al. (2016) study on verticalization to TBI patients. For the ethical considerations of the patients, informed consent will be collected from the patient’s next of kin shown effective from previous research (Frazzitta et al., 2016). The study would also have to be approved by the Institutional Review Board before any research is performed. Following previous research methods, data will be marked independently with each patient and kept separate from the identifiers guaranteeing anonymity for the patients (Majdan et al., 2011).
This study is not one of a kind but more of an addition to previous research performed using the GCS, proving the study’s feasibility. This study would better illustrate the correlation between a GCS score and the outcome of a patient proving the reliability and accuracy of it. The proposed design would also define which cause of accident could prove the scale to be more accurate than others and show evidence of it. Though the patients aren’t put at any additional risk, consent given from these patients would help in research of the GCS thus helping to improve, accept or reject its use in everyday medical treatments.
References
Frazzitta, G., Zivi, I., Valsecchi, R., Bonini, S., Maffia, S., Molatore, K., & ... Saltuari, L. (2016). Effectiveness of a very early stepping verticalization protocol in severe acquired brain injured patients: A randomized pilot study in ICU. Plos ONE, 11(7), 1-15. doi:10.1371/journal.pone.0158030
Khanal, K., Bhandari, S. S., Shrestha, N., Acharya, S. P., & Marhatta, M. N. (2016). Comparison of outcome predictions by the Glasgow Coma Scale and the full outline of UnResponsiveness score in the neurological and neurosurgical patients in the intensive care unit. Indian Journal Of Critical Care Medicine, 20(8), 473-476. doi:10.4103/0972-5229.188199
Laureys, S., Bodart, O., & Gosseries, O. (2014). The Glasgow Coma Scale: time for critical reappraisal? The Lancet Neurology, 13(8), 755-757. http://dx.doi.org/10.1016/S1474-4422(14)70152-8
Majdan, M., Mauritz, W., Brazinova, A., Rusnak, M., Leitgeb, J., Janciak, I., & Wilbacher, I. (2011). Severity and outcome of traumatic brain injuries (TBI) with different causes of injury. Brain Injury, 25(9), 797-805. doi:10.3109/02699052.2011.581642
Mattar, I., Liaw, S. Y., & Chan, M. F. (2015). Nurses’ self-confidence and attitudes in using the Glasgow Coma Scale: A primary study. Nursing in Critical Care, 20(2), 98-107. doi:10.1111/nicc.12077
Naghibi, T., Madani, S., Mazloomzadeh, S., & Dobakhti, F. (2016). Simvastatin's effects on survival and outcome in traumatic brain injury patients: A comparative study. Turkish Journal of Medical Sciences, 46(1), 1-5. doi:10.3906/sag-1404-125
National Institute of Neurological Disorders and Stroke (NINDS). (2013, May 17). Introduction: what is traumatic brain injury? Retrieved from http://www.brainline.org/content/2013/05/what-is-a-traumatic-brain-injury.html
Onita, R., Kirby, D., & Eisenhut, M. (2015). Is the Glasgow Coma Scale score in children in the emergency department lower during the night? Journal of Emergency Nursing, 41(5), 404-406. http://dx.doi.org/10.1016/j.jen.2015.02.004
Teasdale, G. (2014). What is the Glasgow Coma Scale? Retrieved from http://www.glasgowcomascale.org/what-is-gcs/#references
Teasdale, G., Maas, A., Lecky, F., Manley, G., Stocchetti, N., & Murray, G. (2014). The Glasgow Coma Scale at 40 years: standing the test of time. The Lancet Neurology, 13(8), 844-854. http://dx.doi.org/10.1016/S1474-4422(14)70120-6
