After obtaining approval and informed consent from each parent, 80 children, based on the American Society of Anesthesiologists physical status class (I and II), age six months to one year, from both genders scheduled to undergo cleft palate repair surgery, were selected and included in this prospective randomized study that was done at our pediatric hospital (Tanta University Hospital, Egypt) from June 2017 to April 2018. The trial was approved by Tanta Faculty of Medicine Research Ethics Committee with approval code of 31531/05/17 and registered at the Pan African Trial registry (identification number; PACTR201710002426237 at 2017/07/14).
The exclusion criteria were: children with the known severe cardiovascular disease, cerebral, hepatic illness, children with lower or upper respiratory tract infection; having purulent nasal discharge, fever, or with a cough, and those with renal dysfunction or neuromuscular diseases. Preanesthetic checkup and routine investigations were done for all children. The patients were kept nil by mouth for 4 hours for breast milk, 6 hours for milk formula, and 8 hours for solid food and 2 hours for clear fluid. Thirty minutes before the induction of anesthesia, all patients were pre-medicated with 0.5 mg/kg of oral midazolam.
Upon admitting to the operating room, peripheral venous access was obtained using a 22 G catheter and the pediment solution 10 mL/kg was infused with cefazolin 50 mg/kg for antibiotic prophylaxis. Non-invasive monitors, such as electrocardiogram, non-invasive blood pressure, oxygen saturation, and bispectral index (BIS) were attached for recording baseline parameters such as heart rate, mean arterial pressure, peripheral oxygen saturation, and the depth of anesthesia. The study was single-blind and the participants were randomly allocated to two groups: 40 patients each at 1:1 allocation ratio, using an on-line randomization program (www.randon.org).
Group I (40 patients): In this group, general anesthesia was induced with fentanyl one µg/kg, propofol 2.5 mg/kg, and after the loss of consciousness, the muscle was relaxed with cisatracurium 0.15 mg/kg intravenous. To prevent propofol injection pain, 0.1 mg/kg of lidocaine was added. The children were intubated with tracheal tubes. Maintenance of anesthesia was started immediately after the loading dose by a continuous infusion of propofol 9 mg/kg/hr and cisatracurium 3 µg/kg/hr by two syringe drivers. Group II (40 patients): In this group, general anesthesia was induced with O2/sevo (FiO2 = 1/sevoflurane, 8% MAC), fentanyl one µg/kg and after loss of consciousness, the muscle was relaxed with cisatracurium 0.15 mg/kg immediately. Then the maintenance of anesthesia was carried out by O2/air (FiO2 = 0.4), sevoflurane 2% MAC, and cisatracurium 3 µg/kg/hr.
In both groups, cisatracurium was given immediately when BIS value became between 40 - 60, lungs were mechanically ventilated in pressure-controlled mode. The pressure and frequency were adjusted to deliver adequate tidal volume and to maintain normocapnia (EtCO2 30 ± four mmHg). All children were received dexamethasone 0.1 mg/kg intraoperatively. The depth of anesthesia was assessed by BIS and hemodynamic parameters such as heart rate, blood pressure, lacrimation, and sweating. Following the skin incision or at any time during the procedure, an increased heart rate, mean blood pressure or BIS value more than 20% above the baseline was defined as the insufficient depth of anesthesia. All children received acetaminophen (40 mg/kg) rectally after the induction to ensure adequate analgesia after discharge.
All cases were operated by the same surgeon and at the end of the surgery, both types of anesthesia were switched off and the neuromuscular blockade was reversed by neostigmine (0.05 mg/kg) and atropine (0.02 mg/kg) slowly intravenously. The children were successfully extubated when the patients met the criteria of extubation (return of gag reflex, facial grimace, and purposeful motor movements) and transferred to the post-anesthesia care unit (PACU). In the PACU, they were observed closely to detect any complications or adverse events and discharged when Aldrete score ≥ 9. The routine analgesic intake started 6 hours after surgery with 30 mg/kg of rectal paracetamol and repeated every 8 hours up to 48 hours postoperatively. The postoperative pain was assessed using the FLACC behavioral pain assessment scale (
6), if pain scores ≥ 5 at rest, the patient received paracetamol 10 mg/kg IV.
The primary outcome was the quality of emergence, while the secondary outcome was postoperative laryngeal spasm. The quality of emergence was assessed by modified Hannallah score (
7), in which crying, moving, and agitation were assessed separately and scored either (zero or one, or two, and the maximum distress score was six). Postoperative laryngeal spasm (identified by airway obstruction at different severity with paradoxical chest movement, intercostal retraction, and tracheal tug. Also, characteristic crowing sound may be heard in partial laryngospasm but was absent in complete laryngospasm). Laryngospasm was scored as follows: (1 = mild (snoring,), 2 = moderate (stridor), 3 = severe (apnea and cyanosis) (
8). The recovery time was the time interval between the cessation of maintenance anesthetics till the eye-opening, and time to extubation was defined as the time from the discontinuation of sevoflurane to the removal of the endotracheal tube within a minute. Postoperative nausea and vomiting (PONV), hypotension and bradycardia were assessed during the first 24 hours.
3.1. Statistics
A pilot study, including 10 children, was performed with the technique used for both groups (five patients per group). The sample size calculation was based on estimating a 30% change in modified Hannallah score. A calculated sample size of 80 patients would be required to attain the power of at least 80% and 5% significance level with a 90% confidence interval. Therefore, we enrolled 40 patients in each group. Statistical analyses were performed using Statistical Package for the Social Sciences (version 15, SPSS Inc., Chicago, IL, USA). Statistical significance of categorical variables between the groups was compared using chi-square test and quantitative variables were compared using unpaired t-test. Quantitative variables were presented as mean ± standard deviation (SD), while ordinal data are presented as the percentage. P ≤ 0.05 was considered statistically significant.