Can intracranial hemorrhage (ICH) cause hypertensive crisis?

From the Guidelines

Yes, intracranial hemorrhage (ICH) can cause hypertensive crisis through a phenomenon known as Cushing's response or Cushing's reflex, where the body increases blood pressure to maintain adequate blood flow to the brain when intracranial pressure rises. This is a physiological response triggered by the accumulation of blood inside the skull, which increases pressure on the brain tissue, leading to powerful sympathetic nervous system activation, extreme vasoconstriction, and elevated blood pressure 1. The current recommendations for managing blood pressure in patients with acute ICH suggest that lowering systolic blood pressure to a target range of 130 to 140 mm Hg may be reasonable in improving functional outcome, but acute lowering of systolic blood pressure to <130 mm Hg is potentially harmful and should be avoided 1.

Pathophysiology of Cushing's Response

The brain stem, particularly the medulla oblongata, plays a crucial role in triggering Cushing's response, leading to a triad of symptoms: hypertension, bradycardia, and irregular breathing patterns. This triad is a classic indicator of Cushing's triad and requires immediate neurosurgical evaluation. The hypertension from intracranial bleeding is often severe and difficult to control with standard antihypertensive medications.

Management of Hypertensive Crisis in ICH

Management of hypertensive crisis in ICH typically focuses on addressing the underlying bleeding rather than aggressively treating the hypertension, as the elevated blood pressure may be necessary to perfuse the brain. The 2022 guideline for the management of patients with spontaneous intracerebral hemorrhage recommends careful titration of blood pressure-lowering therapy to ensure continuous smooth and sustained control of blood pressure 1.

Key Considerations

• Elevated blood pressure on presentation is associated with greater hematoma expansion, neurological deterioration, death, and dependency 1.
• Results from randomized clinical trials on early intensive blood pressure lowering after ICH have been equivocal 1.
• A balanced approach to managing intracranial pressure makes use of simple and less aggressive measures, such as head positioning, analgesia, and sedation, and then progresses to more aggressive measures as clinically indicated 1.

From the Research

Intracranial Hemorrhage and Hypertensive Crisis

• Intracranial hemorrhage (ICH) is a serious medical condition that can lead to increased intracranial pressure (ICP) and potentially cause hypertensive crisis 2, 3.
• The relationship between ICH and blood pressure management is complex, with elevated blood pressure being a strong predictor of poor outcome in both ICH and subarachnoid hemorrhage (SAH) 4, 5.
• Studies have shown that intensive blood pressure lowering can be safe and effective in improving functional outcomes and overall health-related quality of life in patients with ICH 4, 5.

Blood Pressure Management in ICH

• The American Stroke Association suggests that if systolic blood pressure (SBP) is greater than 180 mmHg and there is no evidence of elevated intracranial pressure, a modest reduction of blood pressure should be considered 5.
• A nationwide survey revealed that SBP lowering to ≤ 160 mmHg using intravenous nicardipine in acute ICH is a major strategy in Japan, and the safety was confirmed by a multicenter, prospective, observational study 5.
• The INTERACT and ATACH trials have shown the feasibility and safety of early rapid blood pressure lowering to 140 mmHg in patients with acute ICH 5.

Outcome and Blood Pressure Control

• Studies have shown that improved outcome in both mortality and severe morbidity is observed in patients with lower mean arterial pressure (< 145 mmHg and < 125 mmHg) 6.
• Markedly elevated blood pressure on admission and persistent inadequate blood pressure control have been shown to adversely affect the prognosis in hypertensive intracerebral hemorrhage 6.
• The optimal blood pressure control in acute hypertensive intracerebral hemorrhage remains a topic of controversy, with the need for a balance between promoting further bleeding and preventing hypoperfusion with secondary ischemia 6.