A 64-year-old woman with a history of hypertension and hyperlipidemia presents with sudden onset headache and stupor. She is taken by ambulance to a nearby emergency department (ED); en route she is given 2 mg midazolam because of seizure-like activity. In the ED, the patient is minimally responsive to pain with a flaccid right arm and increased tone in her lower extremities and is subsequently intubated. Noncontrast head computed tomography (CT) demonstrates hyperdensity in the sylvian fissure and basilar cisterns and intraventricular hemorrhage (IVH). Her third and lateral ventricles are notably dilated. She is diagnosed with subarachnoid hemorrhage (SAH) with IVH and early hydrocephalus and is transferred to the neurologic intensive care unit (NeuroICU) for further management.
On arrival to the NeuroICU she is examined with no sedation and is found to not follow commands. Her pupils are symmetrically reactive, and she moves her left side purposefully but is flaccid in her right upper extremity. Vital signs are heart rate, 90 bpm; respiratory rate, 18 breaths per minute; temperature, 37.4°C (99.4°F); and blood pressure, 120/73 mm Hg (Figure 22-1).
Noncontrast head computed tomography of a 64-year-old woman after admission to the NeuroICU.
Does this patient need an external ventricular drain (EVD)? What are the indications for EVD placement?
This patient’s presentation is consistent with Hunt and Hess (HH) grade IV and Fisher grade 3 SAH (see Chapter 1 for information on SAH grading). Radiographic evidence of acute hydrocephalus along with neurologic decline (failure to follow commands) call for emergent placement of an external ventricular drain (EVD) to alleviate intracranial hypertension. EVDs serve three primary functions in SAH: to monitor intracranial pressure (ICP), to drain cerebrospinal fluid (CSF) for treatment of hydrocephalus, and/or to acutely reduce ICP. EVD placement is therefore indicated when a patient is thought to have symptomatic hydrocephalus and/or elevated ICP based on neurologic examination and radiographic findings.
Ventriculostomy is considered standard-of-care for treating SAH-associated hydrocephalus and has been shown to improve both short- and long-term outcomes.1,2 However, there is no standard, evidence-based guideline for EVD placement in patients with SAH. Although the Glasgow Coma Scale score (eg, ≤ 12)3,4 and HH grade (eg, ≥ III)5 have been used to establish an objective threshold for ventriculostomy, the procedure should be generally considered in patients who demonstrate clinical or radiologic deterioration or have an unreliable neurologic examination. Patients who present comatose or severely lethargic are typically considered for emergent ventriculostomy (Figure 22-2).6,7 Minimal improvement in neurologic status despite normalization of the ICP in these patients may point to other etiologies such as seizure, medication effect, or metabolic derangement and prompts immediate investigation. Improvement in HH grade following ventriculostomy placement in patients scoring poor grade (IV and V) has been shown to predict more favorable long-term outcomes....