Stroke-associated pneumonia is a common and clinically important complication after acute ischemic stroke, especially in non-intubated patients with impaired consciousness and reduced cough or swallowing reflexes. Conventional oral or nasal suction may be insufficient for removing deep oropharyngeal secretions. This prospective randomized controlled trial will evaluate whether a patented oropharyngeal flushing suction tube combined with direct laryngoscopy reduces the 28-day incidence of stroke-associated pneumonia compared with laryngoscope-guided standard suction and conventional oral/nasal suction.

This is an investigator-initiated, single-center, prospective, three-arm, parallel-group, randomized controlled trial. A total of 120 adult patients with acute ischemic stroke, Glasgow Coma Scale scores of 6 to 12, and no artificial airway or invasive mechanical ventilation at enrollment will be randomized in a 1:1:1 ratio to one of three groups: oropharyngeal flushing suction tube plus laryngoscope, standard suction tube plus laryngoscope, or conventional oral/nasal suction. All groups will receive standard stroke care and routine oral care. The primary outcome is the incidence of stroke-associated pneumonia within 28 days after enrollment. Secondary outcomes include 28-day all-cause mortality, establishment of artificial airway or invasive mechanical ventilation, longitudinal inflammatory biomarkers, pathogen distribution and multidrug-resistant organism detection, and procedure-related adverse events.

Inclusion Criteria:

1. Confirmed acute ischemic stroke by cranial CT or MRI.
2. Age 18 years or older.
3. Glasgow Coma Scale score of 6 to 12.
4. No artificial airway and no requirement for invasive mechanical ventilation at enrollment.
5. Written informed consent provided by the participant or legally authorized representative.

Exclusion Criteria:

1. Existing artificial airway or invasive mechanical ventilation at ICU admission or screening.
2. Pre-existing pulmonary infection at enrollment, or definite extra-pulmonary organ or tissue infection during the study period.
3. Hemorrhagic blood disorder, clinically significant coagulopathy, or bleeding risk precluding laryngoscopy.
4. Oral or maxillofacial deformity impeding laryngoscope insertion.
5. Cervical spine fracture, atlantoaxial instability, or other condition restricting neck extension or movement.
6. Confirmed or suspected pregnancy.
7. Irreversible critical illness with anticipated survival less than 28 days.
8. Uncontrolled hypertension or recurrent malignant arrhythmias.
9. Other conditions judged by investigators to make participation unsuitable.

Identifiable or raw individual participant data will not be publicly shared. After publication of the primary results, de-identified data may be made available to qualified researchers upon reasonable written request, subject to ethics committee approval and a data-sharing agreement.

Due to the nature of the procedural and device intervention, participants' bedside care providers and operators cannot be blinded. Stroke-associated pneumonia diagnosis and adverse event classification will be performed by independent outcome assessors blinded to group allocation.