Med Surg Neuro Practice From Lecture
The nurse is caring for a patient who is admitted after a head injury. When would the nurse obtain most of the data related to this patient's mental status? While observing patient behaviors During the nursing health history While asking specific problem-solving questions While reviewing answers on a written mental examination
Answer: B Rationale: Much of the mental status (or cerebral functioning) exam can be assessed as the nurse interacts with the patient during the nursing history.
A patient with a head injury has an arterial BP of 92/50 mm Hg and ICP of 18 mm Hg. The nurse uses the assessments to calculate the cerebral perfusion pressure (CPP). How should the nurse interpret the results? The CPP is so low that brain death is imminent. The CPP is low, and the BP should be increased. The CPP is high, and the ICP should be reduced. The CPP is adequate for normal cerebral blood flow.
Answer: B Rationale: The cerebral perfusion pressure (CPP) is the pressure needed to ensure blood flow to the brain. CPP is equal to the MAP minus the ICP (CPP = MAP - ICP). MAP = DBP + 1/3 (SBP-DBP) = 50 + 1/3 (92-50) = 64 mm Hg CPP = MAP - ICP = 46 mm Hg Normal CPP is 60 to 100 mm Hg. CPP <50 mm Hg is associated with ischemia and neuronal death. A CPP <30 mm Hg results in ischemia and is incompatible with life. It is critical to maintain MAP when ICP is elevated. A patient with a head injury may require a higher blood pressure, increasing MAP and CPP, to increase perfusion to the brain and prevent further tissue damage.
The nurse is caring for a patient who has a spinothalamic tract lesion. Which assessment finding would the nurse expect? Cranial nerve dysfunction Decreased level of consciousness Loss of peripheral sensitivity to pain Reduced extremity movement and strength
Answer: C Rationale: The spinothalamic tracts are responsible for sensations of vague touch, pain, and temperature. A spinothalamic tract lesion could result in loss of peripheral sensitivity to pain.
A patient with increased ICP is positioned in a lateral position with the head of the bed elevated 30 degrees. The nurse evaluates a need for lowering the head of the bed when the patient experiences ptosis of the eyelid. unexpected vomiting. a decrease in motor functions. decreasing level of consciousness.
Answer: D Rationale: Decreasing level of consciousness indicates increased intracranial pressure. Maintain the patient with increased ICP in the head-up position and prevent extreme neck flexion, which can cause venous obstruction and contribute to elevated ICP. Adjust the body position to decrease the ICP maximally and to improve the CPP. Elevation of the head of the bed reduces sagittal sinus pressure, promotes drainage from the head via the valveless venous system through the jugular veins, and decreases the vascular congestion that can produce cerebral edema. However, raising the head of the bed above 30 degrees may decrease the CPP by lowering systemic BP. Careful evaluation of the effects of elevation of the head of the bed on both the ICP and the CPP is required. Position the bed so that it lowers the ICP while optimizing the CPP and other indices of cerebral oxygenation.
