Cuffed Versus Uncuffed Tracheal Tubes in Neonates Undergoing Elective Surgery

Neonates will be recruited into the trial during pre-operative assessment. Recruited neonates will be randomly assigned to one of two groups in a 1:1 ratio; (group C) to receive a cuffed ETT and (group U) to receive an uncuffed ETT for airway management. Randomization will be achieved using a computer-generated sequence. Concealment will be achieved using opaque envelopes.

All neonates will be anesthetized in accordance with the local policy of pediatric anesthesia unit in Abu El-Reesh pediatric hospital-Cairo university after ethics committee approval.

After preoperative examination and upon arrival to the operating room heart rate, noninvasive blood pressure NBP and oxygen saturation SPO2 will be monitored using standard monitor (drȁger infinity vista XL) before inhalational induction of anesthesia using titration of sevoflurane in oxygen air mixture 60% (starting from 3% up to 8%) until the neonate is put to sleep. Baseline lung ultrasound will then be done. After securing an intravenous line anesthesia will be completed with 1-2µg/kg of fentanyl and atracurium 0.5 mg/kg.

Induction of anesthesia will be performed by the attending senior anesthesia resident who has finished at least 2 years of residency (who is independent of the study team).

(Microcuff®, Halyard Health Inc., Atlanta, GA, USA), will be chosen for cuffed TTs, and (Mallinckrodt® Contour Murphy Eye) for non-cuffed tubes.

The appropriate ETT size will be decided by the attending anesthesia resident and will be based on the absence of resistance to insertion of the tube and the presence of audible leak (with inflation pressures of 20 cmH2O following initial cuff deflation for the cuffed ETT group). As necessary, ETT sizes will be adjusted one size up or down to achieve these conditions starting from 3mm internal diameter size.

For both groups: intubation trials will not exceed 2 times, or it will be excluded from the study.

Following inflation of the ETT cuff in C group, pressure will be measured using cuff manometry (Portex Limited, Hythe, Kent, UK) with cuff pressures will be monitored continuously, and if necessary, adjusted to pressures ≤ 20 cmH2O to allow for a good cuff seal without hyperinflation of the cuff.

Measurements will be carried out under both volume- controlled ventilation (VCV) and pressure-controlled ventilation (PCV) using (G.E-Datex-Ohmeda, Avance CS2, USA). Ventilation will be set initially to VCV of 6 ml/kg and PEEP 3 cmH2O. three anesthesia workstation measurements of inspiratory and expiratory tidal volumes will be recorded, and the mean taken for analysis of leakage around the ETT. Ventilation will then be adjusted to PCV of 10 cmH2O, PEEP of 3 cmH2O and leakage around the tube analyzed again in the same way. Then these measurements will be done again at 10 min and 20 min. Once these measurements are taken, ventilation will be continued as VCV of 6-8 ml/kg, PEEP 3 cmH2O and respiratory rate will be set between 30-40 to maintain end tidal CO2 within 30-40 mmHg for the remainder of the case.

At the end of the procedure and before return of spontaneous ventilation another set of measurements will be recorded.

In both groups, after return of spontaneous ventilation the neonates will be put on pressure support PS mode (PS 10, PEEP 3 and flow trigger of 1 L/min) and when the neonate is capable of triggering at least 70% of his own breathes and has good motor power; the ETT will be removed by the attending anesthetist after reversal of muscle relaxant effect using neostigmine 0.05 mg/kg with atropine 0.02 mg/kg and timing of extubation will be recorded.

All patients will be transported to the post anesthesia care unit PACU after ensuring that their airway and oxygenation are adequate. Oxygen saturation will be measured continuously until discharge from the PACU. Oxygen saturation will be recorded when the neonates are calm and the pulse oximeter showing consistent detection. Lowest measured SpO2 values will be recorded 10 min before removal of the ETT, and at 1 min, 5 min, 10 min, 15 min, 20 min and 30 min after removal.

Any respiratory adverse events (laryngospasm; bronchospasm; desaturation < 95%; airway obstruction; severe coughing and/or postoperative stridor) as well as subsequent interventions will be recorded and managed according to the local policy of Abo El Reesh pediatric hospital. All postoperative measurements will be collected by PACU nurse who is independent of the study team.