Design and Setting
This study is a prospective, randomized, comparative, single-blind study comparing the effects of two different anaesthesia methods on the waking time and EA in children undergoing bronchoscopy. This study was approved by the Medical Ethics Committee of the Second Affiliated Hospital and Yuying Children’s Hospital of Wenzhou Medical University and registered at the China Clinical Trial Registry on September 21, 2019(http://www.chictr.org.cn) (ChiCTR1900026098).The study began to recruit patients on October 10, 2019. This study adhered to the applicable CONSORT guidelines.
According to the previous preliminary test, the average recovery time of the experimental group was 15.58 min, α= 0.05, and β = 0.1, and the difference between the two groups reached 5.78; namely, the difference between the two groups was considered statistically significant. Using PASS software for the calculation, the sample size was 25 cases per group, considering a 20% dropout rate of the clinical sample. The final sample size was 60 patients, with 30 patients per group.
After obtaining written informed consent from the parents of each child, 60 children with ASA (American Society of Anaesthesiologists physical fitness classification) grade I or II aged 1-3 yrs who were scheduled for an FOB examination were included. The exclusion criteria were a BMI <14 or >28, haemoptysis, treatment and removal of foreign bodies through an FOB examination, neurological and endocrine system diseases, a family history of malignant hyperthermia, a long-term medication history, children with allergies to soybeans, and any situation that the researchers believe may affect the evaluation of the scale.
Patients were randomly allocated to different groups using a computer-generated digit-number program (SAS PLAN; SAS Institute Inc.) before starting the study and identified in numbered sealed envelopes. On the day of the operation, we randomly selected one envelope and opened it approximately 30 min before anaesthesia. The patient was administered a different anaesthesia regimen according to the randomized group. The researcher was aware of the group chosen throughout the study, while data recorders and processors were blinded to the group assignment during the study.
According to ASA guidelines, the children complied with principles of fasting and drinking. A peripheral venous catheter was inserted prior to the operation. Heart rate (HR), noninvasive blood pressure (NIBP), pulse oxygen saturation (SpO2), end-expiratory carbon dioxide pressure (PEtCO2) and anaesthetic gas concentration were monitored. After preoxygenation via a face mask, the children in the remifentanil group (group R) were induced with 4 mg•kg-1 propofol and 4 μg•kg-1 remifentanil (slow intravenous injection). After the eyelash reflex disappeared, the laryngeal mask airway (LMA) was inserted. Anaesthesia was maintained with 0.3-0.5 μg•kg-1•min-1 remifentanil. The pressure-controlled ventilation parameters were adjusted to maintain PETCO2 between 35 and 45 mmHg. The children in the sevoflurane group (group S) were induced with 2 mg•kg-1 propofol and 8% sevoflurane. After the eyelash reflex disappeared, the LMA was inserted. Anaesthesia was maintained with 4-6 vol% sevoflurane and retained spontaneous respiration. The bronchoscope was introduced through a bronchoscopy adaptor connected to the LMA after general anaesthesia had been established. Topical lidocaine was sprayed to the glottis vera and trachea before FOB.
During the FOB examination, if SpO2 <90% lasted for more than 30 s in group S, assisted ventilation by a balloon was provided until SpO2 returned to normal. If the BP was less than 70% of the baseline, phenylephrine was administered, and if it was more than 130% of the baseline, urapidil was administered. If the HR was less than 70% of the baseline, 0.01 mg/kg atropine was administered, and if it was more than 130% of the baseline, esmolol was administered. In cases of continuous choking, laryngeal spasm or bronchospasm during FOB, the patients in group R were administered a single dose of 2 mg•kg-1 propofol to increase the depth of anaesthesia, and the patients in group S were administered an increased inhaled sevoflurane concentration with topical lidocaine sprayed onto the airway again. The procedure was stopped and complications were treated if serious adverse events, such as severe hypoxia, bradycardia, and arrhythmia, occurred. Additionally, 1 mg•kg-1 propofol was administered via IV for EA if the patient was determined to be pain-free and when the parent or caregiver was unable to comfort the child.
After the completion of FOB, all drugs were stopped, and the LMA was removed from children with spontaneous breathing. Then, the patients were moved to the postanesthesia care unit (PACU), and the children naturally regained consciousness. EA was assessed by the study staff upon arrival in the PACU using the Paediatric Anaesthesia Emergence Delirium (PAED) scale (0–20 scale), with a score of > 10 considered a diagnosis of EA(10). Finally, patients with an Alderete score ≥ 9 were sent back to the ward.
A CRF (case report form) was designed for the registration of clinical data and study results. Data were stored in a password-protected computer to ensure patients’ confidentiality. The study closely followed the guidelines of GCP (good clinical practice). One investigator was explicitly responsible for data collection, filing, and transmission, while another investigator was explicitly responsible for verifying the data accuracy and safety.
Primary outcomes: The waking time was recorded, and EA was assessed with the PAED in the PACU every five minutes.
Secondary outcomes: MAP, HR, and SpO2 were monitored and recorded at four time points: baseline (T0), when the bronchoscope reached the glottis (T1), the time of lavage (T2), and the end of the brush biopsy (T3). Any complementary medicine and adverse events were also recorded. Finally, the satisfaction scores of physicians were recorded (0 points = satisfied; 1 point = basically satisfied; 2 points = dissatisfied).
The Kolmogorov-Smirnov test was used to test the normality of the measurement data, and Levene’s test was used to test the homogeneity of the variance of the measurement data. If the measurement data displayed a normal distribution, they were presented as the means ± standard deviations (Mean ± SD), and the parametric test was used for comparisons between groups; otherwise, results are presented as the medians (interquartile ranges) (Median (QR)) and nonparametric tests were used for comparisons between groups. If the measurement data displayed a normal distribution and homogeneity of variance, the two groups were compared using Student’s t-test. If the measurement data displayed a normal distribution with unsatisfactory homogeneity of variance, the nonparametric test of two independent samples was suitable for the experiment. Repeated measurement data were analysed using repeated-measures ANOVA and P <0.05 was considered statistically significant. Count data are reported in absolute numbers (percentages), and comparisons between groups were performed using the χ2 test or Fisher’s exact probability method. Moreover, we use SPSS 24.0 for data analysis.