Evaluation of the Effect of Mouth Gag Application on Ultrasonographic Optic Nerve Sheath Diameter of Pediatric Patients Undergoing Tonsillectomy or Adenotonsillectomy: Observational study

Abstract

<jats:title>Abstract</jats:title> <jats:p>Background: Mouth gag is usually used during Adeno/tonsillectomy surgeries, cleft palate repair, obstructive sleep apnea surgery and intraoral tumor excision. The placement of gag causes hemodynamic changes similar to laryngoscopy. The aim of this study is to evaluate the effect of mouth gag placement on optic nerve sheath diameter (ONSD) of pediatric patients. The secondary aim is to assess the relationship between neck extension for positioning of head and increase in ONSD measurement. Methods: The trial is registered to Australian New Zealand Clinical Trials Registry with Trial ID: ACTRN12618000551291. This prospective, observational study was performed in a tertiary university hospital operating theatre between 01.05.2018-01.07.2018. Thirty-five children aged &lt; 18 years, with ASA I status, and scheduled for adeno/tonsillectomy surgeries were prospectively included in the study. Measurements of ONSD were performed (T0) after induction of anesthesia, (T1) after endotracheal intubation, (T2) after the placement of mouth gag and (T3) 20 minutes after the placement of mouth gag. The degree of neck extension was assessed by the angle between the Frankfort plane and horizontal plane of the operation table in natural position Results: All participants completed the study. There were significant differences in ONSD values according to time (p &lt; 0.001). The maximum increase in ONSD values was detected after intubation (0.69±0.06 mm) and immediately after mouth gag placement (0.67±0.07 mm). ONSD values continued to increase 20 minutes after the gag placement. There was no relation between degree of neck extension and ONSD values (b = 0.63, p=0.715) Conclusions: Mouth gag application causes significant increases in ONSD measurements of children. Therefore, the duration of mouth gag application during surgeries might be limited. Trial registration: The trial is registered to Australian New Zealand Clinical Trials Registry with Trial ID: ACTRN12618000551291.</jats:p>