Safety implications of the Boyle-Davis mouth gag and tracheal tube position in tonsillectomy

Evaluation of the effect of the mouth gag use on optic nerve sheath diameter of pediatric patients undergoing tonsillectomy or Adenotonsillectomy: An observational study

BACKGROUND

A mouth gag is usually used during tonsillectomy and adenotonsillectomy surgeries, cleft palate repair, obstructive sleep apnea surgery, and intraoral tumor excision. The placement of the gag causes hemodynamic changes similar to laryngoscopy. The aim of this study was to evaluate the effect of mouth gag placement on the optic nerve sheath diameter (ONSD) of pediatric patients. The secondary aim was to assess the relationship between neck extension and changes in ONSD.

METHODS

The trial was prospectively registered to the Australian New Zealand Clinical Trials Registry (Trial ID: ACTRN12618000551291) on 12.04.2018. This prospective, observational study was performed in a tertiary university hospital operating room between 01.05.2018-01.07.2018. Thirty-five children aged < 18 years, with ASA I status, who were scheduled for tonsillectomy and adenotonsillectomy surgeries were prospectively included in the study. Measurements of ONSD were performed (T0) after induction of anesthesia, (T1) after endotracheal intubation, (T2) after mouth gag placement, and (T3) 20 min after mouth gag placement. After the mouth gag was placed and the head was positioned for surgery, the degree of neck extension was calculated.

RESULTS

All participants completed the study. There were significant differences in ONSD values at time points T1, T2, and T3 (p < 0.001, CI: - 0.09,-0.05; p < 0.001, CI: - 0.09,-0.05; p < 0.001, CI: - 0.05,-0.02; respectively). The maximum increase in ONSD was after intubation (0.69 ± 0.06 mm) and immediately after mouth gag placement (0.67 ± 0.07 mm). ONSD values continued to increase 20 min after gag placement (0.36 ± 0.04). There was no relation between the degree of neck extension and ONSD values (β = 0.63, p = 0.715).

CONCLUSIONS

The use of a mouth gag causes significant increases in ONSD measurements of children. Therefore, attention to the duration of mouth gag placement should be considered during surgery.

TRIAL REGISTRATION

The trial was prospectively registered to the Australian New Zealand Clinical Trials Registry (Trial ID: ACTRN12618000551291 ) on 12.04.2018.

Evaluation of the effect of Boyle-Davis mouth gag on intracranial pressure in patients undergoing adenotonsillectomy by using ultrasonographic optic nerve sheath diameter measurement

OBJECTIVE

We aimed to evaluate the effect of an increase in intracranial pressure (ICP) due to sympatho-adrenergic response caused by mouth gag and tongue depressor during adenotonsillectomy by measuring the optic nerve sheath diameter (ONSD) by ultrasonographic method.

METHODS

Forty patients (age range 3-12 years) who underwent adenotonsillectomy were included in the study. All patients underwent surgery under general anesthesia with endotracheal intubation. Boyle-Davis mouth gag was used during the procedure. ONSD measurement was performed and a high-frequency linear probe. All ONSD measurements were performed by a single investigator experienced in the use of ultrasound. Ultrasonographically measured ONSD before induction was accepted as baseline (T0) value. Immediately after insertion of the mouth gag (T1), just before removal of the mouth gag (T2), and just before extubation (T3), ultrasonographic measurements of ONSD were recorded.

RESULTS

When patients' baseline ONSD values were compared with the values obtained in T1, T2, T3, and a statistically significant increase was detected. The ONSD value measured before removing the mouth gag (T2) was significantly higher than the ONSD value measured immediately after the insertion of the mouth gag (T1). The ONSD value measured just before extubation (T3) and after removal of the mouth gag was significantly lower than the ONSD value (T2) measured just before removal of the mouth gag. When heart rate, mean arterial pressure (MAP), peripheral oxygen saturation (SpO₂) values of T0, T1, T2, T3 were compared, any statistically significant difference was not observed. When end-tidal carbon dioxide level (etCO₂) and peak inspiratory pressure (PIP) values of T1, T2, T3 were compared, any statistically significant difference was not observed.

CONCLUSION

This study showed that the Boyle-Davis mouth gag used during the adenotonsillectomy operation resulted in a significant increase in the diameter of the optic nerve sheath measured ultrasonographically and increased the ONSD even further during the time the mouth gag was remained in situ. In children with intracranial pathologies who will undergo adenotonsillectomy or those with increased ICP-related risk factors, the risks that may arise from the effect of the Boyle-Davis mouth gag on ICP should be considered.

Massive pneumomediastinum with subcutaneous emphysema after elective adenotonsillectomy in children: Involvement of the Boyle-Davis mouth gag

Adenotonsillectomy, a very common surgical procedure in otorhinolaryngology, is considered easy and safe surgery. However, clinicians should be aware of some less common but potentially life-threatening complications. This report discusses subcutaneous emphysema with pneumomediastinum following elective adenotonsillar surgery in children. The Boyle-Davis mouth gag seemed to play a part in the pathogenic mechanism of this rare complication in this case. Better insights in the mechanism of this severe complication of adenotonsillectomy may contribute to the prevention of this complication.

Ambulatory anesthesia aspects for tonsillectomy and abrasion in children

PURPOSE OF REVIEW

Tonsillectomy is a very common procedure, but with risks or challenges, both for the surgeon and anesthesiologist. Many places have considerable experience and expertise with this procedure, and a lot of clinical studies are continuously being presented.

RECENT FINDINGS

Most preoperative aspects are covered, including indications, preoperative risk assessment, premedication, anesthetic induction and maintenance, as well as recovery function and side-effects; such as bleeding, agitation, pain, nausea and sleep apnea. Controversies exist as to ambulatory versus in-patient care, laryngeal mask airway versus endotracheal intubation, use of local anesthetic infiltration and use of glucocorticoids.

SUMMARY

Preoperative evaluation should identify increased bleeding risk, potential airway problems, ongoing infection and symptoms of obstructive sleep apnea.Intravenous propofol is most often used for anesthetic induction, although inhalational sevoflurane is a valid alternative. Laryngeal mask airway or endotracheal tube may both be used safely and effectively; the choice will depend upon the routine and experience of the team. Paracetamol and NSAIDs are useful baseline medication for nonopioid multimodal postoperative pain treatment and prophylaxis. Similar with local anesthesia infiltration and dexamethasone medication, although somewhat more disputed. Dexamethasone is also useful for nausea/vomiting prophylaxis, together with ondansetron and also propofol for anesthesia maintenance.