This clinical prospective randomized trial was approved by the Research Ethics Committee of the Faculty of Medicine, Tanta University (code 32321/05/2018). It was also registered before patient enrollment at the Pan African Clinical Trial Registry on 13 July 2018 (PACTR201807466395693). The study was conducted at the Department of Pediatric Surgery, Tanta University Hospitals from July 2018 to April 2019.
Children with tongue laceration admitted for elective repair under general anesthesia, aged 2 to 5 years, with American Society of Anesthesiologists (ASA) Class I or II, and in the fasting state were included in this study. The exclusion criteria consisted of patients with a full stomach (who underwent general anesthesia with endotracheal tube), active bleeding, tongue hematoma, predicted difficult airway, or the history of gastro-esophageal reflux.
In the preoperative period, the parents were asked about the cause of the tongue trauma and the medical history of their children, especially the history of epilepsy. Then, the general and local examination of the child was done with requesting laboratory investigations, especially coagulation studies. The purpose, advantage, procedure, and potential risks of this research work were adequately explained to the parents of children in detail with the reassurance that their children will receive the optimal and safe medical care. If they agreed to participate in the study, the guardian of each child would sign a written informed consent. The children were presented to surgery after fasting for 6 h from solid food and 2 h from clear fluids. The patients were randomly assigned into two groups according to the method used for securing airway through the aid of computer-generated software and closed sealed envelopes.
Endotracheal Tube (ETT) Group: In this group, the airway was secured by suitably sized cuffed right-angle endotracheal (RAE) tube according to the patient’s age and weight.
Flexible Laryngeal Mask Airway (LMA) Group: In this group, the airway of the patient was secured using flexible laryngeal mask airway of suitable size according to the weight of the patient.
The suitably sized laryngoscope and endotracheal tube and the suction device and catheter were prepared before the induction of anesthesia. A standardized anesthetic technique was used in all cases through the inhalational induction of anesthesia using sevoflurane 6% in 80% oxygen administrated through a facemask. An assistant helped in the establishment of intravascular access through the insertion of the 22-gauge peripheral venous cannula and the patient was attached to the basic 5 ASA monitoring (pulse oximeter, three-lead electrocardiogram, non-invasive blood pressure, end-tidal carbon dioxide, and temperature). All patients received 0.01 mg/kg of atropine intravenously. Fentanyl 1 μg/kg was then administrated intravenously.
The adequate depth of anesthesia was judged by the absence of increased heart rate or limb movement in response to jaw thrust. When it was achieved, the airway of the child was secured by the same expert anesthetist according to the group of the patient without the use of muscle relaxants. The presence of gagging or coughing during the trial to secure airway was managed by the restoration of face mask ventilation using sevoflurane inhalation until the achievement of the adequate depth of anesthesia. The airway was considered to be secure when there was bilateral chest elevation with positive capnograph wave during hand ventilation and movement of the bag during spontaneous ventilation. If patients in the laryngeal mask group had inadequate ventilation, the laryngeal mask was replaced by a suitably sized endotracheal tube and the patient was excluded from the study.
The anesthesia was maintained by inhalational anesthesia through sevoflurane 3.5% in oxygen to air of 1:1 and spontaneous ventilation. Any increase in the heart rate or mean arterial pressure during the surgery by more than 10% of the baseline values was managed by fentanyl 1 μg/kg intravenously. The surgical field was monitored adequately for the presence of excessive blood loss or tissue debris.
At the end of the surgery in the ETT group, sevoflurane was switched off with full awake extubation of the patient after careful suction of blood or secretions. In the LMA group, the mask was removed after careful suction while the patient was in deep anesthesia; then, the inhalational anesthetic was switched off. In both groups, face mask ventilation continued. When the modified Aldrete scale reached score 8 or more, the patient was transferred to the recovery room with the continuous monitoring of the patient for the modified Aldrete scale every 15 min. The patient was discharged from the recovery room when the modified Aldrete scale reached to score 10.
An assistant nurse, out of the research team, who was blinded to the study helped in the measurement of the following variables: intubation time that represented the time interval in seconds from the removal of the facemask until the insertion and securing of LMA or ETT (The assistant nurse who helped in measurement of the intubation time should be blind to the group of the patients and this could not be obtained as she can identify the method used for airway control in each patient (ETT or LMA) by naked eye. So, she was kept away from the patients and informed when the face mask was removed to start counting of time till she was informed that the airway is secured.); surgical time that was calculated as time in minutes from the start of the surgery until its end; total anesthesia time that represented the number of minutes elapsed from the start of anesthesia induction until the patient’s transfer to the recovery room; extubation time (primary outcome) that was the time in minutes elapsed from the end of the surgery to the transfer of the patient to the recovery room; and recovery time that represented the number of minutes from the arrival to the recovery room until discharge from it. Moreover, the hemodynamic data including heart rate and systolic arterial pressure were recorded before the induction of anesthesia, after the induction of anesthesia, after airway securing, at the beginning of the surgery, and at the end of the surgery.
At the end of the surgery, the surgeon was asked to evaluate the surgical exposure as 1 = extremely poor, 2 = poor, 3 = accepted, 4 = good, and 5 = optimal. Moreover, the incidence of perioperative adverse events as trauma to lip, gum, teeth, or larynx, gagging, coughing, laryngeal spasm or bronchospasm, stridor, and sore throat were recorded. Patients who developed laryngeal spasm were managed by increasing the inspired oxygen tension with the assistance of the ventilation while doing jaw thrust and the stimulation of the laryngeal notch. The patients who developed stridor were managed by oxygen supplementation with intravenous injection of dexamethasone 0.1 mg/kg and close observation. Additionally, inhaled bronchodilators and systemic corticosteroids were used in children who developed bronchospasm. All the patients that had developed adverse events were managed by conservative and medical treatment and none of them required re-intubation.
3.1. Statistical Analysis
A preliminary study was conducted on 10 patients (who were not included in the final study) presented for tongue trauma repair under general anesthesia with either the endotracheal tube (five patients) or the flexible laryngeal mask airway (five patients). The extubation time was significantly lower in the LMA group (7.34 ± 5.77 min) than in the ETT group (16.03 ± 5.54 min). As a result, at least 36 patients were required in each group to detect a significant difference by 5 min in the extubation time with the study power of 95% and the α value of 0.05. The dropout rate was assumed to be 20%; thus, 45 patients were required in each group. The SPSS computer program (SPSS Inc, Chicago, IL, USA) was used for the statistical analysis of the recorded data by either unpaired t-test for parametric data presented as means and standard deviations or Fisher’s exact test for numerical data presented as numbers and percentages. The Mann-Whitney U test was used to analyze the surgical exposure score expressed as medians with interquartile ranges. The values were considered statistically significant when the P values were less than 0.05.