Initial Stabilization

In stroke patients presenting to the ED, the first goal of treatment is immediate cardiac and respiratory stabilization. The systemic blood pressure is most often elevated in the setting of an acute stroke as the result of a catecholamine surge, and if the patient is hypotensive, the clinician should consider a concomitant cardiac process, such as myocardial infarction (MI), congestive heart failure (CHF), or pulmonary embolism (PE).

Stroke patients commonly have airway compromise, either secondary to a depressed level of consciousness or due to mechanical dysfunction of the airway from the stroke itself. Either mechanism can increase the risk for aspiration in the acute setting. Furthermore, patients with large hemispheric strokes or lesions involving the brainstem may be particularly prone to emesis, another predisposing factor for aspiration. The emergency physician must weigh the risks of the patient aspirating in this setting versus the loss of aspects of the neurological exam when the patient does require intubation, since medications used during intubation will nearly always influence the neurological examination. In addition, an endotracheal tube will preclude spoken language. Certainly, if the patient is considered unstable or imminently unsafe in the physician's judgment, then elective intubation should ensue, but a cursory neurological examination should be performed first when possible.

Stroke patients who require mechanical ventilation are not necessarily destined for a poor outcome. In a study by Santoli et al.,5 58 patients underwent mechanical ventilation and 16 survived. Eleven achieved a Barthel Index (BI) score of 60, indicating a good outcome. Within this study population, those patients with bilaterally absent corneal and pupillary reflexes had uniformly poor outcomes, underscoring the need for careful assessment of brainstem reflexes in intubated stroke patients. Other factors that have been associated with poor outcome in intubated stroke patients are advanced age and lower Glasgow Coma Score (GCS) at the time of intubation,6 as well as seizures and pulmonary edema.7

Once intubated, the patient should be placed on the most minimal settings that will allow for normocarbia and adequate oxygenation. The positive end-expiratory pressure (PEEP) should be kept <10 cm H2O (optimally as low as 5 cm H2O), as higher levels of PEEP may impair venous return to the heart and theoretically increase the ICP. Georgiadis et al.8 evaluated the effect of different inspiratory:ex-piratory (I:E) ratios on patients with stroke and subarachnoid hemorrhage who were undergoing intracranial monitoring. They did not find any significant variation in the cerebral perfusion pressures (CPP) with varying I:E ratios, but it should be noted that their study did not include patients who had elevated ICPs, and thus the effect in patients with significant cerebral edema should remain in question.

It is difficult to predict if a neurologically injured patient will successfully be extubated. Salam et al.9 studied 88 patients prospectively, measuring cough peak flow (CPF), endotracheal secretions, and the ability to complete four simple tasks prior to extubation. In patients who failed extubation, they had a lower CPF (p = 0.03), higher amount of secretions (RR 3.0, 95% CI 1.0-8.8), and diminished ability to complete the four simple tasks (RR 4.3, 95% CI 1.8-10.4).

If a stroke patient receives intravenous (IV) thrombolysis, care often continues in the ED until the patient arrives in the ICU. Close monitoring must continue during this time, with special attention to the blood pressure. The blood pressure is most commonly checked via an arm cuff, since the placement of invasive lines (e.g., arterial catheterization) is relatively contraindicated once the patient has received intravenous thrombolysis (unless the situation is emergent and mandates such treatment). The systolic pressure must not exceed 185 mm Hg, and the diastolic pressure limit should be 110 mm Hg. Should the blood pressure exceed these limits, IV antihypertensive agents should be administered. IV pushes of labetolol (10-20 mg over 1-2 minutes) may be effective, but if patients are refractory to these initial measures then a continuous infusion of labetolol (0.5-2.0 mg/minute), nicardipine (5-15 mg/hour), or nitro-prusside (0.25-10 mg/kg/minute) may be necessary to keep the patient's blood pressure within the range. There will be a more detailed discussion of these antihypertensive agents, including their side effect profiles, later in this chapter.

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