Objective To determine the half-effective target plasma concentration(EC50)of remifentanil inhibiting airway response when combined with propofol by TCI in patients undergoing fiberoptic bronchoscopy.Methods Forty ASAⅠorⅡ patients,aged 20-64 yr, undergoing elective fiberoptic bronchoscopy, were randomly divided into 2 groups (n = 20 each).Anesthesia was performed with TCI of remifentanil and propofol in both groups. The target effect site concentration of propofol was 3 μg/ml.The target effect site concentration of remifentanil was determined by up-and-down sequential hial. The target effect site concentration of remifentanil was set at 5 μg/ml in the first patient and the ratio of the target concentrations between the two consecutive patients was 1.1. BIS ≤ 60 was defined as the suitable depth of anesthesia in group A.The airway response≤grade Ⅱ was defined as the suitable depth of anesthesia in group B. The EC50 and 95% confidence interval (CI) required to inhibit the airway response were calculated in the two groups.Results The EC50 and 95% CI of remifentanil required to inhibit the airway response were 4.50μg/L (95% CI 3.88-5.36 μg/L)in group A and 4.10μg/L(95% GI 3.31-5.00 μg/L) in group B. The EC50 of remifentanil inhibiting airway response was significantly higher in group A than in group B. Conclusion The EC50 of remifentanil inhibiting airway response is 4.10 μg/L when combined with propofol by TGI (effect site concentration 3μg/ml)in patients undergoing bronchoscopy. BIS is not a suitable index assessing the depth of propofol-remifentanil anesthesia.

Intracranial seminoma is a rare malignant tumor originating from the germ cells,usually occurring in the pineal gland or pituitary gland.In June 2020,the Department of Endocrinology at the First Affiliated Hospital of Army Military Medical University admitted a 20-year-old male patient with an intracranial germ cell tumor and spinal metastases.The patient presented with headache,dizziness,and visual impairment.Enhanced magnetic resonance imaging(MRI)of the head indicated thickening of the pituitary stalk.After multidisciplinary consultation,the patient underwent endonasal transsphenoidal resection of the tumor,with the pathological diagnosis confirming germ cell tumor.The patient received regular radiotherapy postoperatively.One year later,the tumor recurred and metastasized,leading to a second surgery for tumor resection in the thoracic spinal canal,followed by continued chemotherapy.The patient's clinical symptoms,such as headache and visual disturbances,improved,but he continued to experience panhypopituitarism and required long-term hormone replacement therapy.Early diagnosis of intracranial germ cell tumors is challenging,and they are prone to metastasis and highly sensitive to radiotherapy and chemotherapy.Early diagnosis and multidisciplinary comprehensive treatment can help improve the quality of life and prognosis for patients.