600 comatose patients admitted to the hospital in China from June 2024 to June 2028 were randomly divided into groups A and B. Group A used intermittent negative pressure suction through oral and pharyngeal ventilation, while group B used continuous negative pressure suction through regular oral and nasal suction.

Research content: (1) Selection and placement methods of oropharyngeal ventilation tubes, studying the application effects of different models and sizes of oropharyngeal ventilation tubes in critically ill patients, exploring the best placement method to improve the efficiency and safety of sputum suction operations. (2) The norms and techniques of sputum suction, the steps, techniques, and precautions of sputum suction, the depth, strength, time of insertion, and when to interrupt negative pressure, in order to minimize damage to the patient's respiratory mucosa. (3) Evaluation of patient comfort and tolerance, assessing the tolerance and potential adverse reactions of critically ill patients during oral pharyngeal intubation for sputum suction, providing a basis for optimizing sputum suction. (4) Evaluation of sputum suction effect, comparing blood oxygen saturation, respiratory distress, sputum sounds, and other indicators before and after sputum suction to evaluate the effectiveness of sputum suction.

Inclusion Criteria:

• 1. Clinical diagnosis of stroke; 2. Clinical diagnosis of comatose;

Exclusion Criteria:

• 1. Clinical diagnosis of multiple organ failure; 2. Clinical diagnosis of multiple organ bleeding;