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A 34-year-old right-handed woman with a history of smoking presents with a sudden onset of severe occipital headache followed by loss of consciousness that started while cleaning her bathroom. In the emergency department she is found to be arousable to deep stimulation, her pupils are poorly reactive at a 3-mm diameter, and she is withdrawing to painful stimulation bilaterally. When her mental status further decline she is intubated for airway protection. Head computed tomograpy (CT) scanning (Figure 16-1) reveals a subarachnoid hemorrhage (SAH), with thick blood filling the basal cisterns, hydrocephalus, and bilateral intraventricular hemorrhage (IVH). CT angiography reveals an aneurysm of the anterior communicating artery (ACoM). She is transferred to the nearest tertiary medical care center.
Cerebral angiography reveals an 8 × 4-mm ACoM aneurysm that is coiled on SAH day 1 (Figure 16-2). Additionally, angiography reveals severe, bilateral anterior cerebral artery vasospasm that improves after treatment with 12 mg of intraarterial (IA) verapamil. The postprocedural CT scan reveals global cerebral edema and increasing evidence for hydrocephalus. An external ventricular drainage (EVD) catheter is placed. Postoperatively, the patient is found to be in coma with intact brain stem reflexes, bilateral posturing to painful stimulation, and bilateral positive Babinski signs. At that time, the treating physicians decides to place a multimodality neuromonitoring bundle through a right frontal burr whole consisting of a parenchymal intracranial pressure (ICP) monitor, a brain tissue oxygenation probe, and an MD catheter.
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What is the purpose of invasive neuromonitoring in comatose patients?
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One of the most important goals of neurologic critical care is to detect secondary brain injury at a time when permanent damage can still be prevented. The clinical examination remains the gold standard for the assessment of patients with neurologic disease despite great advances in neuroimaging and other diagnostic tools. Furthermore, in medical intensive care unit (ICU) patients daily interruption of sedation has been shown to decrease duration of mechanical ventilation, shorten hospital stay, and in combination with spontaneous breathing trials lead to improved outcome.1,2 There is some evidence suggesting that daily interruption of sedation is safe even in patients with brain injury,3 but this remains controversial.4 Neurologic wake-up trials have been associated with a cardiorespiratory stress response, increased stress hormone levels, and episodes of raised ICP > 20 mm Hg in patients with acute brain injury.3,5,6 Multimodal neuromonitoring techniques may allow the interruption of sedation safely by identifying patients in whom sedation holidays ...