Critical Care Medicine-Neurologic Disorders>>>>>Management Strategies
Question 4#

A 57-year-old man, with past medical history of hypertension and hyperlipidemia, presented with an acute onset of slurred speech and right-sided weakness. He was diagnosed with an acute left middle cerebral artery (LMCA) stroke and IV tPA was administered. He was then admitted to the ICU for close monitoring. On day 3 poststroke, his focal deficits persist, and it is noted that one of his pupils is larger than the other. He subsequently becomes unresponsive and is emergently intubated and hyperventilated. Stat head CT demonstrated increasing cerebral edema and midline shift of 9.6 mm and uncal herniation without signs of cerebral hemorrhage.

What is the most appropriate next step in treatment?

a. Transfuse to keep the hemoglobin>10 mg/dL
b. Administer IV dexamethasone
c. Administer hypertonic saline
d. Readminister IV tPA at half the original dose

Correct Answer is C

Comment:

Correct Answer: C

The patient suffered an extensive MCA stroke and did not improve with IV thrombolytics. Brain edema and ICP are often associated with occlusion of large intracranial arteries. Edema of the brain begins to develop during the first 24 to 48 hours and reaches a maximum extent of 3 to 5 days from the occurrence of acute ischemic stroke. The presentation described is classic for uncal herniation secondary to increasing edema, with pressure on midbrain causing a CN III palsy manifested by a blown pupil. Because post-stroke edema is cytotoxic in nature and vasogenic edema occurs secondarily (as opposed to perineoplastic changes), steroids are not beneficial (Option B is incorrect). In fact, it has been shown that steroid administration in the setting of acute stroke worsens outcomes. Although increasing cerebral edema could cause secondary cerebral ischemia by compressing healthy brain tissue, there is no indication to increase transfusion threshold (Option A is incorrect). Redosing tPA could be detrimental in the settings of a large stroke and should not be attempted (Option D is incorrect). Treatment of stroke-related cerebral edema is osmotherapy, such as hypertonic saline (Option C is correct) or mannitol. Following this initial intervention, the patient should be evaluated for possible hemicraniectomy.

References:

  1. Ayata C, Ropper AH. Ischaemic brain oedema. J Clin Neurosci. 2002;9(2):113-124.
  2. Bar B, Biller J. Select hyperacute complications of ischemic stroke: cerebral edema, hemorrhagic transformation, and orolingual angioedema secondary to intravenous alteplase. Expert Rev Neurother. 2018;18(10):749-759.