Neutrophil elastase is a serine protease secreted by neutrophils that plays a crucial role in the onset and progression of various respiratory diseases. The imbalance between neutrophil elastase and its endogenous inhibitors can contribute to the onset and progression of respiratory diseases such as chronic obstructive pulmonary disease, cystic fibrosis, bronchiectasis, and acute respiratory distress syndrome. The excessive release of neutrophil elastase contributes to multiple pathophysiological processes, such as disruption of the alveolar–capillary barrier, oxidative stress and inflammatory responses, autophagy, and apoptosis. The use of neutrophil elastase as a biomarker in disease assessment and prognosis prediction as well as the potential of neutrophil elastase inhibitors in clinical treatment have shown broad application prospects. Neutrophil elastase inhibitors have certain limitations such as off-target effects, poor lung bioavailability, cost considerations, and variability in patient responses. This article reviews the literature on neutrophil elastase and its inhibitors in the field of respiratory diseases, aiming to provide new insights into the diagnosis and treatment of related respiratory diseases.

Nasotracheal intubation is commonly used in clinical practice for procedures requiring general anesthesia, mechanical ventilation, and emergency treatment of critically ill patients. It provides a good surgical field and operating space for maxillofacial surgeries, offers an artificial airway for long-term mechanically ventilated patients in the intensive care unit, and presents a new method for emergency and difficult airway intubation patients. Compared to orotracheal intubation, nasotracheal intubation has advantages such as minimal stimulation to the throat, good patient tolerance, easy fixation, facilitation of oral care, and longer duration of placement. However, it requires higher technical skill from the operator and has a higher incidence of complications like epistaxis and sinusitis, which have restricted its widespread application. From the early blind intubation method to the current direct laryngoscopy, video laryngoscopy, and fiberoptic bronchoscopy, the success rate of nasotracheal intubation has gradually increased while the incidence of complications has decreased. In this review article, we summarize the common methods, advantages and disadvantages of nasotracheal intubation, as well as the research progress on related complications and coping strategies, aiming to enhance the application of this technology in clinical practice.

Nasotracheal intubation is commonly used in clinical practice for procedures requiring general anaesthesia, mechanical ventilation, and emergency treatment of critically ill patients. It presents a new good surgical field and operating space for maxillofacial surgeries, offers an artificial airway for long-term mechanically ventilated patients in the Intensive Care Unit (ICU), and provides a method for emergency and difficult airway intubations. Compared to orotracheal intubations, nasotracheal intubation has advantages such as minimal stimulation to the throat, good patient tolerance, easy fixation, facilitation of oral care, and longer duration of placement. However, it requires higher level of technical skill from the operator and carries a higher incidence of complications like epistaxis and sinusitis, which have restricted its widespread application. From the early blind intubation method to the current direct laryngoscopy, video laryngoscopy, and fibreoptic bronchoscopy, the success rate of nasotracheal intubation has increased, while the incidence of complications has decreased. This review summarises the common methods, advantages and disadvantages of nasotracheal intubation, as well as the research progress on related complications and coping strategies, aiming to enhance the application of this technology in clinical practice.