Background Alveolar recruitment maneuvers (ARMs) is an important part of lung-protective ventilation strategies (LPVSs), but the optimal duration and interval Remain unclear. Methods Patients:252 patients who underwent holmium laser lithotripsy surgery and meet inclusion criteria were included and randomized into three groups based on the duration and frequency of ARMs (Regular, one 30 s ARM (RARMs); Improved and intermittent, three 10s ARMs (IARMs); and Control (C), no ARMs).Interventions: Groups R and I received ARMs at 20 cmH2O pressures every 30 min. All patients received the same anesthesia and mechanical ventilation. Measurements:Outcomes included heart rate and mean arterial pressure changes during ARMs and postoperative pulmonary complications (PPCs) within the first 7 postoperative days. Main results Incidences of PPCs in groups R(7.1%) and I (5.0%)were slightly lower than those in group C (8.9%).This indicated the potential to reduce lung injury. Heart rate and mean arterial pressure fluctuations during ARMs were significantly higher in groups R and I than in group C (P < 0.01). The rate of blood pressure decrease was significantly higher in group R than in group I (P < 0.01). Conclusions IARMs can reduce cycle fluctuations than RARMs in patients Undergoing holmium laser lithotripsy surgery with laryngeal mask general anesthesia. Low tidal volume ventilation and low PEEP combined with ARM did not significantly reduce the incidence of PPCs in healthy lung patients, but tended to reduce lung injury. Trial registration The study was registered on the Chinese Clinical Trial Registry. (ChiCTR2000030815,15/03/2020). This study was approved by the ethics committee of Chengdu Fifth People’s Hospital with approval number(2020–005(Study)-1).

BackgroundDifficult airway has always been one of the greatest challenges for anesthesiologists. Patients with difficult airways and severe obstructive sleep apnea-hypopnea syndrome (OSAHS) often find themselves in life-threatening danger before their artificial airway is established and after their artificial airway is removed.Case presentationThe study reported a case of nasal polyps shedding into the tracheal tube when nasotracheal intubation in a patient diagnosed with a difficult airway and OSAHS; the patient was being prepared for a transoral tonsillectomy under general anesthesia. The uniqueness of this case was that nasal polyps were scraped off using the tracheal tube during nasotracheal intubation, and detected in real-time; this ultimately prevented an airway foreign body obstruction. Reviewing the literature on intubation methods for difficult airways, awake endotracheal intubation guided by fiberoptic bronchoscopy remains to be the gold standard for airway management. Additionally, nasotracheal intubation can provide more operating space for oral surgery. In this case, the unexpected nasal polyp fell off into the tracheal tube during intubation, as is visualized on the following pictures. This fortunate event prevented the nasal polyp from falling into the trachea and bronchus.ConclusionIt is necessary to rule out any nasal abnormalities in patients requiring nasotracheal intubation; otherwise, blind nasal intubation may be dangerous.