What are the possible causes and recommended management for a 72‑year‑old female intubated for a presumed stroke who now exhibits an abnormal irregular (diagonal) breathing pattern after a CT scan, in the absence of hypotension, shock, or metabolic derangements?

Abnormal Breathing Pattern in Intubated Stroke Patient

This patient's irregular "diagonal" breathing pattern after CT scan most likely represents an abnormal respiratory pattern signaling brainstem dysfunction from rostrocaudal deterioration of a large hemispheric stroke, and requires immediate reassessment for clinical deterioration, consideration of osmotic therapy, and urgent neurosurgical consultation for possible decompressive craniectomy. 1

Recognition of Deteriorating Stroke with Abnormal Breathing

Abnormal respiratory patterns indicate late-stage brainstem dysfunction in supratentorial stroke:

• Irregular breathing patterns—including ataxic respiratory patterns, periodic breathing, and central neurogenic hyperventilation—typically occur late in the course of deterioration from hemispheric infarction and signal lower brainstem dysfunction 1
• These respiratory abnormalities represent rostrocaudal deterioration, progressing from initial pupillary changes and motor deterioration to eventual irregular breathing and death 1
• The American Heart Association emphasizes that abnormal respiratory patterns develop after ipsilateral pupillary dysfunction, worsening limb power progressing to extensor posturing, and contralateral Babinski signs from brainstem notching 1

Central periodic breathing (CPB) is common but carries poor prognosis:

• Cheyne-Stokes respiration occurs in approximately 50% of acute stroke patients, causing cyclic oxygen desaturation 2
• CPB is independently associated with poor outcome—91% of patients with CPB were dead or dependent at 3 months compared to 53% without CPB (OR 8.8) 3
• This association persists even after adjusting for stroke severity and other covariates (adjusted OR 5.9) 3

Immediate Clinical Assessment Required

Perform urgent neurological examination for signs of herniation:

• Check pupils bilaterally for mydriasis, midposition pupils, or anisocoria—these indicate progressive transtentorial herniation 1
• Assess motor responses for progression from localization to flexion rigidity or extensor posturing 1
• Monitor for bradycardia, which along with irregular breathing may indicate further brainstem compression 1

Obtain repeat head CT immediately:

• Patients with massive cerebral infarction at risk of malignant swelling require serial physical examinations and repeat head CT to identify worsening brain swelling 4
• Look for midline shift, effacement of basal cisterns, and increased mass effect 1

Management Algorithm

Step 1: Optimize Ventilation and Oxygenation

• Maintain normocapnia with PaCO₂ 4.5-5.0 kPa (approximately 34-38 mmHg) and SpO₂ ≥95% 4
• Avoid hyperventilation unless acute herniation is suspected, as it may worsen cerebral ischemia 1
• Ensure adequate mean arterial pressure is maintained, though evidence-based target levels are not established 1

Step 2: Initiate Osmotic Therapy

• Administer osmotic therapy immediately for clinical deterioration from cerebral swelling 1
• Options include mannitol or hypertonic saline as a bridge to definitive surgical intervention 1
• Some centers use 1.5% saline as maintenance fluid in patients with early CT swelling 1

Step 3: Urgent Neurosurgical Consultation

• Rapid transfer to centers with neurosurgical expertise is recommended if the condition is deemed survivable 4
• Decompressive craniectomy should be considered for patients with large hemispheric infarction showing clinical deterioration despite medical management 1
• Mechanical ventilation may be needed after decompressive surgery, but neurological improvement is anticipated and liberation from ventilator may be expected in the first postoperative days 1

Supportive Care Priorities

Hemodynamic management:

• Maintain SBP >110 mmHg and <185 mmHg for acute ischemic stroke 4
• Avoid marked hypertension, anxiety, or dyssynchrony with the ventilator through appropriate sedation 1

Metabolic optimization:

• Avoid hyperglycemia exceeding 180 mg/dL, as it is associated with increased edema and hemorrhagic transformation 1
• Maintain normothermia; treat temperatures >37.5°C 1
• Use isotonic saline and avoid hypo-osmolar fluids 1

Prevent complications:

• Continue subcutaneous heparin or low-molecular-weight heparin for deep venous thrombosis prophylaxis, even with early edema on CT 1
• Monitor with prolonged EEG if fluctuating consciousness raises concern for seizures, though seizure prophylaxis is not recommended 1
• Elevate head of bed 15-30° to optimize venous drainage and reduce aspiration risk 5

Critical Pitfalls to Avoid

• Do not delay intervention waiting for multiple deterioration criteria—abnormal respiratory patterns alone indicate advanced brainstem dysfunction requiring immediate action 1
• Do not attribute irregular breathing to ventilator dyssynchrony without ruling out neurological deterioration—this represents a late and ominous sign 1
• Do not withhold osmotic therapy pending neurosurgical evaluation—use it as a bridge to definitive intervention 1
• Recognize that intubated stroke patients have up to 50% mortality within 30 days, but timely intervention before irreversible damage improves outcomes 4, 6

Prognosis Considerations

• Overall 1-year survival for mechanically ventilated stroke patients is 33%, better than historically reported 6
• Independent predictors of poor outcome include age >65 years, GCS <10, and intubation for coma or acute respiratory failure 6
• The presence of abnormal respiratory patterns indicates advanced deterioration and warrants frank discussion with family about goals of care while pursuing aggressive intervention 1