Post Extubation Delirium and End-tidal Sevoflurane Concentration

Association Between Post Extubation Delirium and Pre-extubation End-tidal Sevoflurane Concentration in Children

The purpose of this study is to determine whether the incidence of emergence delirium will be reduced when end-tidal concentration of sevoflurane decreases.

Sevoflurane induction and maintenance were selected. Intubation was performed after lidocaine spray on vocal cord. After that, an effective caudal or brachial plexus block was performed. End-tidal concentration of sevoflurane was maintained at 2.5%. Spontaneous respiratory was maintained. Sevoflurane was stopped after the end of surgery. Patients were randomly assigned to 2 groups: high concentration group (Group HC, end-tidal concentration of sevoflurane when extubating >=0.5%) and low concentration group (Group LC, end-tidal concentration of sevoflurane when extubating <0.5%). Patients in Group LC were extubated when they coughed or purposeful movement appeared. The patients whose end-tidal concentration of sevoflurane >= 0.5% were excluded. Patients in Group HC were extubated when any of the criteria was met: 1.the patient coughed or purposeful movement appeared 2.end-tidal concentration of sevoflurane decreased to 0.5%. A trained nurse (blind to groups) recorded PAEDs scores in PACU.

The primary outcome was the number of participants with emergence delirium (ED) according to the peak PAED score measured by Pediatric Anesthesia Emergence Delirium Scale. All PAED (Pediatric Anesthesia Emergence Delirium scale) scores were assessed by a dedicated nurse who was blinded to the random assignment of patients to group. PAED scores were assessed on awakening (defined as reactive to verbal command or opening of eyes or crying in response to slight touch) and then every 5 minutes for 30 minutes. If the PAED score was ≥ 16, propofol 1 mg.kg-1 was administrated. After administration of propofol, PAED scores were no longer assessed. The peak (highest) PAED score for each patient was analyzed. ED was defined as a peak PAED score >12. Higher score of PAED means a worse outcome.

Inclusion Criteria: Age 2-7 years ASA I - II Estimated surgery time < 2 hours Sevoflurane induction and maintenance along with caudal block or Axillary Block Exclusion Criteria: Craniofacial anomalies Difficult exposure of the vocal cordS Obesity Asthma Invalid caudal block or axillary block