Traumatic Brain Injury and Anesthetics
In today’s day and age, it is extremely common for individuals to be faced with multiple injuries within a relatively short time frame. The exact reasoning behind this increase has not yet been determined. There is a possibility that a connection can be made between the injuries and substance abuse, distracted driving, and/or any other events that have a negative impact on the general population’s physical and mental health. In some cases, these injuries may or may not be a result of the same event. All conditions call for the same treatment guidelines, therefore, the way one condition is treated may worsen the other. When specifically analyzing brain injuries, many factors must be taken into consideration when composing the patient’s treatment plan. There are two categorizations for brain injuries. An acquired brain injury is a more generalized term to describe a less severe injury to the brain. On the other hand, a traumatic brain injury (TBI) is a more severe injury to the brain that results in a disruption in brain pathology or function. The discussion of how traumatic brain injury (TBI) patients are impacted by the use of anesthetic drugs is an important one. The effect of general anesthetics on an injured brain can be detrimental. This article will analyze the definition of a TBI and a general anesthetic in addition to discussing the associated risks, current practices, and future research applications.
What is a traumatic brain injury?
A traumatic brain injury (TBI) has been known to present itself in a variety of forms. It is defined as a forceful jolt or blows to the head which causes the brain to hit the skull at an accelerated speed (Centers for Disease Control and Prevention, 2019a). A TBI can also develop through pierces to the brain such as a bullet, or when sudden forceful movements to the body occur (Centers for Disease Control and Prevention, 2019b). There are a wide variety of TBI cases with differing severity and origin. (Mckee & Daneshvar, 2015). Some patients diagnosed with a TBI are in a comatose state or may have a fractured skull, while others can present with concussive symptoms. The first-line approach of treatment for a TBI is different across patients due to differences in their state of physical and mental health. In some cases, patients taken to the emergency room with a severe head injury are either brought to the operating room to help relieve intracranial pressure or to the intensive care unit for further observation (Agarwal et al., 2020). The main focus of providing care for these TBI patients is preventing a secondary injury while treating the primary brain injury (Agarwal et al., 2020). Many pre-operative considerations are made for each patient to highlighting the benefits and setbacks of the available plans of action. In these pre-operative conditions, the use of general anesthetic is discussed (Zambouri, 2007).
What is a general anesthetic and how does it work?
General anesthesia played? a critical role in the advancement of the medical field. Today, it still remains the only drug that permits a therapeutic loss of consciousness in the patient (Forman & Chin, 2008). A general anesthetic is most often used for procedures that are time-consuming, affecting one’s pulmonary function, and/or involving major blood loss (Saraswat, 2015). The vast majority of general anesthetic agents impact the traditional functionality of the brain regions such as the hippocampus, medial septum, and prefrontal cortex.((Alkire et al., 2008; Leung et al., 2014). Specifically, general anesthesia is able to disrupt communication inside the brain, which in turn impacts its ability to comprehend information (Hudetz, 2012). This results in unconsciousness.
Threats of general anesthetics on the brain and respective considerations
Still to this day, scientists are still unsure about the molecular mechanisms behind the use of general anesthetics (Pavel et al., 2020). We know that general anesthetics active the TWIK-related K+ channels (TREK-1) – a diverse group of water-fearing compounds allowing for the reversible loss of consciousness (Pavel et al., 2020). Research now suggests that the chemical compositions of general anesthetics target the plasma membrane resulting in a loss of consciousness ((Pavel et al., 2020). In sum, how general anesthetics impact our brains poses a challenge in our ability to process information. These effects may increase in severity if there is a brain injury. This can be especially true for those with a diagnosed TBI. TBI patients undergoing anesthesia are at more serious risk of a demolished neural state during the administration of sedatives, particularly if the TBI is extreme or if the general anesthetic is suboptimal for TBI patients. The use of an anesthetic may expose the patient to further conditions such as low oxygen in the blood (hypoxemia), low blood pressure (hypotension), increasing pressure within the skull, or fever (Wilson, 1992). These worsened conditions may contribute to a non-intended outcome (Narotam et al., 2009). The anesthesiologist must be well-informed and especially attentive to TBI patients who are undergoing procedures to ensure no secondary injury or other conditions are developed. Fortunately, medical professionals have now uncovered alternative methods to using general anesthetic on TBI patients that keep the patient safe and prevent further injury (National Institute of Neurological Disorders and Stroke, 2020). It is essential that the anesthetic agent selected for the patient is the safest and most effective option provided the severity of their TBI diagnosis. Knowing the details of the injury, for example, intracranial pressure elevation, can help steer medical professionals towards the use of the safest agent. The medical team should greatly consider the factors of cerebral blood flow, the impact anesthetics have on the cardiac and respiratory system, changes in intracranial pressure, and other measures that could be established to provide neuroprotective benefits to the TBI patient at hand.
Further research in the analysis of different age groups, different severities of TBI, type of procedures in relation to how they combat the complexity of this issue would provide great insight and understanding of other applications of current literature. Future understanding of the effects of general anesthetic on the brain will help the medical team optimize the outcomes of TBI patients (resource). These changes the brain undergoes when a general anesthetic is used will help the attending medical team optimize the outcomes of patients in this population (Rasouli et al., 2020).
References
Hello! My name is Bianca, a first year integrated science student at McMaster University located in Hamilton, Ontario, Canada. Next year, I hope to be concentrating my studies in either math and stats or biology. My research interests lie in pharmacology, cardiology, infectious diseases and public health. Aside from academics, I am currently employed as a pharmacy assistant and I am coaching basketball for grade school youth. On my free time, I enjoy hiking, reading, and catching up with friends!
