Introduction
The brains appropriate functioning is crucial for survival of individuals. That is why, its injuries pose a significant threat to patients lives because they might precondition the appearance of problems with cerebral blood flow and cerebral perfusion. The purpose of this paper is to delve into the peculiarities of these processes regarding the suggested case.
Cerebral Blood Flow and Cerebral Perfusion
In the normal state, the brain uses approximately 20% of all oxygen available in the body (Barman, Chatterjee & Bhide 2016). It means that the regulation of blood flow and oxygen delivery becomes crucial for the functioning of this organ and survival of an individual. Therefore, among healthy people, blood flow to the brain is constant because of the contribution of large arteries to vascular resistance (Ellison et al. 2012). Their functioning maintains cerebral perfusion, which is blood flow to the brain at the appropriate level. However, in case of trauma or blood loss, pressure could become low, and the flow could be limited. It results in the decrease of cerebral perfusion and significant deterioration of the state of a patient. Therefore, the brain has its regulatory mechanism which could protect it from severe damage caused by the lack of oxygen.
Autoregulation of cerebral blood flow is the brains ability to preserve a comparatively constant level of blood flow regardless of alterations in perfusion pressure (Ellison et al. 2012). The given system becomes crucial for individuals survival as it contributes to the preservation of oxygen levels and guarantees the brains functioning. Autoregulation could be observed in numerous vascular beds; however, the brain has the most developed system because of the critical need for a constant blood and oxygen supply (Goodson et al. 2016). Otherwise, if blood flow is insufficient, autoregulation is lost, and the brain might suffer from cerebral ischemia (Itoh & Suzuki 2012). At early stages its symptoms are not seen; however, the brain suffers from the lack of oxygen and its cells are gradually fading (Lafrenaye, Krahe & Poylishock 2014). Under these conditions, preservation of cerebral perfusion becomes the primary task for healthcare specialists as it will also help to support autoregulation of cerebral blood flow and avoid severe brain injuries.
Risk of Loss of CBF Autoregulation
Therefore, as stated above, the risk of loss of CBF autoregulation could contribute to crucial alterations in the state of patients who suffer from serious brain injuries and changes in the level of blood flow. The occurrence of cerebral ischemia is one of the consequences of loss of CBF autoregulation (Kainerstorfer et al. 2015). For this reason, it is crucial to assess the state of a patient to determine the most important indicators. First, Sarah has a severe head injury along with chest, spinal, and limb injuries. She was driven to the hospital unconscious. Regarding the character of her traumas, the risk of loss of CBF autoregulation is high. Patients after traumatic brain injury like Sarah are predisposed to failures of blood flow and to the lack of oxygen delivered to the brain (Cipola 2012). This kind of patients should be checked for primary and secondary brain injuries.
The fact is that the secondary injury caused by dysautoregulation of brain vessels might contribute to the decreased cerebral perfusion pressure and the loss of CBF autoregulation (Nemoto et al. 2014). Regarding Sarahs case, the risk of decreased cerebral blood pressure and insufficient blood flow is high. The patient is conscious and needs intubation and ventilation to preserve oxygen at the appropriate level. Therefore, the brain consumes appropriately 20% of all oxygen available. It means that the organ might suffer from the poor oxygenation. The blood pressure is 92/72. However, the measurement history demonstrates significant oscillations in systolic and diastolic blood pressure, starting from 100/40which could be considered lower than the norm (120/80). Moreover, there are no improvements of the patients state. The combination of these facts evidences the high risk of loss of CBF autoregulation because of the decreased cerebral perfusion. The further examination of the patient is needed to determine the severity of the patients state.
Compensatory Interventions
Considering a severe character of traumas and Sarahs complicated case, numerous compensatory interventions were used to preserve her vital signs at the appropriate level and assist the patient in her recovery. First of all, Sarah was intubated and ventilated to support the body with the oxygen needed for all processes. This intervention is crucial for patients with brain injuries as in the majority of cases their respiration becomes insufficient and cannot perform oxygenation (Lafrenaye, McGinn & Poylishock 2012). Additionally, appropriate levels of oxygen are crucial for the brain and preservation of cerebral perfusion. If the organ does not receive the needed amount of oxygen, it fails to function, and CBF autoregulation could be lost. For this reason, intubation and ventilation become fundamental interventions to support a patient and preserve his vital signs.
Second, the patient is provided with noradrenaline infusion to maintain CPP 60. The measurement history demonstrates that CPP was about 40 and there was the tendency towards its further decrease. Low level of CPP is critical for patients as it has a pernicious impact on the state of the brain which fails to perform CBF autoregulation and suffers from the insufficient blood flow along with anoxia. It could also result in cerebral ischemia and the further deterioration of the patients state. Under these conditions, infusion of noradrenaline becomes essential for patients with head injuries and low CPP as their brain functioning is endangered.
Third, Sarah was sedated using morphine and propofol. Pain management is critical for patients with brain traumas. For this reason, the use of morphine is justified by the necessity to eliminate the consequences of the pain shock and stabilise the patient (Timor-Tritsch et al. 2012). Therefore, regarding the fact that Sarah is ventilated, propofol is needed for sedation of mechanically ventilated patients. The patients revival could be dangerous and cause harm to her. For this reason, intravenous injections of propanol could be considered an appropriate way to sedate a patient and support her during recovery.
Finally, intracranial pressure monitoring becomes another intervention needed to trace alterations in Sarahs state and provide appropriate responses. The fact is that intracranial pressure is essential for the preservation of the brain functioning at the appropriate level. Intracranial pressure is one of the components that maintain the cerebral perfusion pressure. If the intracranial pressure becomes too high, blood flow to the brain may be limited (Chalkias & Xanthos 2013). It will result in the decreased CPP and significant damage to the organ.
Conclusion
The work has discussed the crucial importance of cerebral blood flow and cerebral perfusion with reference to head traumas. The suggested case served as the background for the investigation. It helped to demonstrate the importance of CPP monitoring and compensatory interventions to improve the patients state.
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