A 57-year-old man with history of hypertension and gastric ulcer presents after a sudden onset of severe headache followed by nausea and vomiting. The patient arrived in the emergency department (ED) after becoming stuporous in the ambulance. On arrival at the ED, he was hemodynamically unstable—blood pressure (BP) 80/40 mm Hg—and was promptly intubated. He was given fluid resuscitation with the infusion of 2 L of crystalloids, with blood pressure recovering to 140/80 mm Hg. Computed tomography (CT) of the head revealed acute subarachnoid hemorrhage (SAH) filling the basal cistern, bilateral sylvian fissures with thick hemorrhages (modified Fischer grade 3), and early evidence of hydrocephalus (Figure 15-1). The patient was transferred to the neurologic intensive care unit (NeuroICU, NICU) where an external ventricular drain (EVD) was urgently placed and urgent angiography was planned. Even after EVD placement, the patient remained comatose, with intact brainstem reflexes. Vital signs were as follows: BP 150/70 mm Hg, HR 120 bpm in sinus rhythm, RR 22 breaths/min (mechanical ventilation at assist control–pressure-controlled mode), temperature 37°C.
Patients in the acute phase after aneurysmal SAH are at increased risk for rebleeding. The highest rates of rebleeding occur in the first 3 days after SAH, and therefore clipping or coiling of the ruptured aneurysm should be performed as soon as possible after admission. While the aneurysm is unsecured, systemic hypertension should be avoided but hemodynamic stability is crucial to avoid cerebral hypoperfusion, acute ictal infarcts, and cerebral circulatory arrest.1
Liberal fluid resuscitation with crystalloids is commonly necessary in poor-grade SAH patients before securing the aneurysm. Although frequently hypertensive, patients may present with relative intravascular volume depletion—due to natriuresis and to the systemic inflammatory response associated with severe brain injury—and this was why this patient responded appropriately to 2 L of normal saline, which was necessary to maintain end-organ perfusion. On arrival at the ICU, this patient should receive a central venous access and an arterial line. If a mean arterial pressure (MAP) goal of at least 60 to 70 mm Hg is not achieved, vasopressors and inotropic agents should be initiated. This patient's ruptured aneurysm has not been secured yet, therefore systemic hypertension and intracranial hypertension must be treated promptly. Typically, systolic blood pressure less than 140 to 160 mm Hg or MAP less than 100 mm Hg can be used to as a general target. At this point, urine output, central venous pressure (CVP), arterial lactate levels, and central venous oxygen saturation (ScvO2) are assessed to refine the evaluation of hemodynamic stability. Urine output < 0.5 mL/kg/h, lactate levels above 2 mmol/L, and ScvO2 below 65% generally represent systemic hypoperfusion and further fluid resuscitation should target CVP > 8 mm Hg, ScvO2 > 70%, and the reduction of arterial lactate.2