EC95 Of Remifentanil For Tracheal Tube Tolerance Of Patients After Cervical Spine Surgery

BackgroundSurgeons dissect around the airway inevitablely durning cervical spine surgery, due to which as well as gravity caused in prone position sometimes produce edema, these patients often have a lot of swelling including laryngeal and tracheal edema around the airway and in the neck.It is Necessary to delay extubation under adequate sedation and analgesia.The administration of short-acting opioids remifentanil for tracheal tube tolerance can be a reliable and safe method, but the proper dose or effect site concentration of remifentanil for this purpose has not been reported.We therefore use CRM method to investigated the effect site concentration (Ce) of remifentanil for tracheal tube tolerance with remifentanil target-controlled infusionMethods30 ASAⅠ-Ⅱgrade men patients, aged 18-60 yr undergoing cervical spine surgery were enrolled in this study.EC95 of remifentanil for tracheal tube tolerance were determined using CRM method and Corresponding analysis. This is a double-blind and prospective study. Six dose levels of remifentanil were chosen before the study started, with the probability of tracheal tube tolerance associated with each:1μg/l (30%),1.5μg/l (50%),2μg/l (70),2.5μg/l (85),3.0μg/l (95%) and 3.5μg/kg (99%).Recruited patients were allocated to the same dose of remifentanil by a cohort, each containing 3 individuals. The dose of remifentanil received in each cohort was determined by the responses of all previous patients.Sedation-Agitation Scale(SAS),visual analogue scale (VAS),mean arterial pressure, and heart rate (HR),extubation time,Respiratory inhibition were recorded.ResultsThe EC95 of remifentanil for tracheal tube tolerance was 2.14μg/l by CRM analysis.Analgesia was sufficient in all patients (VAS≤3).twenty-eighet patients(93.3%) reached a SAS 4 with one patient 3 and one patient 5.All the patients were extubate in 5 minutes after stopping remifentanil infusion and the vital signs remained stable.twenty-four patients (80%) were awake and spontaneously with six patients respiratory depressed.ConclusionsWe found that the EC95 of effect site concentration of remifentanil tracheal tube tolerance was 2.77μg/l.Maintaining an established Ce of remifentanil is a reliable method and it allowed extubate in 5 minutes.But we dont recommended to maintenant awake and spontaneously without respiratory support unless under strengthen respiratory care and/or ruduce the dose.