Methods
BRAIN TUMORS, CAVITY
This prospective randomized controlled trial was approved by Institutional Review Board of Chang Gung Memorial Hospital (file number 202102115A3) and registered at clinicaltrials.org (NCT05253404) on 23 February 2022. A data analysis and statistics plans were written and posted on ClinicalTrials.gov.All of 62 patients, aging 20 to 65 years old and American Society of Anesthesiologists’ physical status I to III, undergoing elective craniotomy for brain tumors were recruited from 14 February 2022 until 27 June 2022. They all gave their written informed consents before anesthesia. The exclusion criteria were: anticipated difficult airway and difficult laryngeal mask airway use (mouth opening < 3 cm, Mallampati score > 3, body mass index > 30 kg/mConsort flowchart. ETT, endotracheal tube; LMA, laryngeal mask airway; ETSev-con, End-tidal sevoflurane concentrationStandard anesthesia working station (Carestation 620) consists of electrocardiography, pulse oximetry and muscle power monitor (response to train-of-four stimulation).Following 3 min’ preoxygenation, all patients took induction of anesthesia with fentanyl 1–1.5 mcg/kg, propofol 1.5–2 mg/kg and cisatracurium 0.15–0.2 mg/kg or rocuronium 0.6–1.2 mg/kg injected intravenously. Oral endotracheal intubation was performed using the Clarus Video System (Trachway) with an endotracheal tube (Henan Tuoren) ID 6.5 mm -7.5 mm. Afterwards, an arterial catheter and a central venous line would be set up for all of them. Anesthesia was maintained at end-tidal sevoflurane concentration (ETSev-con) 2.0–2.5% and cisatracurium 0.03 mg/kg repeated every 40–60 min to maintain a muscle response between T1 and T2 on the train-of-four monitor. Ventilator was set to keep end-tidal carbon dioxide (ETCOOnce surgery was completed, oropharyngeal cavity was thoroughly suctioned and the patients were prepared for endotracheal extubation. As the patients had ETSev-con 2.5% and also fully regained muscle power with continuous spontaneous ventilation (Time Zero), they were randomly assigned to ETT Group (The primary purpose of the study was to examine PaO