Which medication should the nurse anticipate administering for a comatose patient with massive cerebral hemorrhage who now has non‑reactive dilated pupils, irregular respirations, severe hypertension with wide pulse pressure, and bradycardia?

Mannitol Administration for Impending Brain Herniation

The nurse should anticipate administration of mannitol (Osmitrol), as this patient exhibits classic signs of impending brain herniation from massive cerebral hemorrhage with critically elevated intracranial pressure. 1, 2

Clinical Presentation Analysis

This patient demonstrates Cushing's triad with additional late signs of herniation:

• Dilated, non-reactive pupils = late sign of critically elevated ICP and impending herniation 3
• Hypertension with wide pulse pressure (BP 170/66, MAP 101) = compensatory mechanism to maintain cerebral perfusion 3
• Bradycardia (HR 40 and irregular) = vagal response to brainstem compression 3
• Irregular respirations = brainstem dysfunction from herniation 3

These findings represent a medical emergency requiring immediate intervention to reduce intracranial pressure before irreversible brain damage occurs. 3

Why Mannitol is the Correct Choice

Mannitol is the first-line osmotic agent specifically indicated for reduction of intracranial pressure and brain mass in patients with threatened intracranial hypertension or signs of brain herniation. 1, 2

Dosing for This Emergency Situation

• Administer 0.25 to 1 g/kg IV over 20-30 minutes 3, 1, 2
• For acute intracranial hypertensive crisis with impending herniation, larger doses of 0.5-1 g/kg over 15 minutes are appropriate 3, 1
• Maximum effect occurs 10-15 minutes after administration, with duration lasting 2-4 hours 3, 1

Mechanism and Advantages

• Creates osmotic gradient that extracts fluid from edematous brain tissue into intravascular space 1
• Associated with improved cerebral oxygenation compared to other therapies 1
• Works as temporizing measure before definitive treatment (surgical decompression if needed) 1

Why the Other Options Are Incorrect

Hydralazine (Apresoline) - CONTRAINDICATED

Aggressive antihypertensive agents with venodilating effects should be avoided because they cause cerebral venodilation and further elevate ICP. 3 The hypertension in this patient is a compensatory response to maintain cerebral perfusion pressure against rising ICP—lowering blood pressure would worsen cerebral ischemia. 3

Atropine Sulfate - INAPPROPRIATE

While atropine treats bradycardia, this patient's bradycardia is part of Cushing's triad and represents brainstem compression from herniation—not a primary cardiac problem. 3 Treating the bradycardia without addressing the underlying elevated ICP would be futile and delay life-saving intervention. The priority is reducing ICP, not increasing heart rate. 3

Metoprolol (Lopressor) - DANGEROUS

A beta-blocker would worsen the already critical bradycardia and potentially reduce blood pressure, compromising cerebral perfusion pressure at a time when the brain desperately needs adequate perfusion. 3 This would accelerate herniation and death.

Critical Nursing Actions Alongside Mannitol

Before administration: 3, 1

• Insert Foley catheter (mannitol causes profound osmotic diuresis) 3, 4
• Administer through filter; do not use solutions containing crystals 3
• Ensure IV access is patent (extravasation causes tissue necrosis) 2

During and after administration: 3, 1

• Elevate head of bed 20-30° with head in neutral position to facilitate venous drainage 3
• Maintain airway patency and adequate oxygenation 3
• Monitor for signs of hypovolemia from diuresis and replace volume as needed 1, 4
• Check serum osmolality every 6 hours; discontinue if >320 mOsm/L to prevent renal failure 1, 2, 4
• Monitor electrolytes (sodium, potassium, chloride) every 6 hours 1

Coordinate with physician for: 3, 1

• Emergency brain imaging if not already done 3
• Neurosurgical consultation for potential decompressive craniectomy 1
• ICP monitoring placement if patient survives initial crisis 1

Common Pitfall to Avoid

Do not delay mannitol administration to "stabilize" blood pressure or heart rate first. 3, 1 The vital sign abnormalities are consequences of herniation—only reducing ICP will reverse them. Every minute of delay increases the risk of irreversible brain damage or death. 3