Effect of neck extension on ultrasonographic optic nerve sheath diameter as a surrogate for intracranial pressure in patients undergoing palatoplasty: A prospective observational study

Effect of neck extension on intraocular pressure in paediatric patients undergoing palatoplasty

BACKGROUND

Intraocular pressure (IOP) can increase with postural changes, which can cause ocular complications. Neck extension is commonly used during palatoplasty to improve surgical angulation. This study evaluates whether neck extension affects IOP during palatoplasty.

METHODS

In this prospective observational study, IOP was measured using a rebound tonometer at four specific time points: T1, 10 min after anaesthesia while in the supine position; T2, 5 min after neck extension; T3, at completion of palatoplasty with neck extended; and T4, 5 min after returning to the supine position. The primary outcome was the IOP at T2, and the secondary outcomes were the IOPs at T3 and T4. Haemodynamic and respiratory variables were also measured at each time point.

RESULTS

Thirty-seven patients were included. IOP at T2 was significantly higher than at T1 (15.8 ± 3.4 mmHg vs 10.5 ± 2.8 mmHg, P < 0.001), and IOPs at T3 and T4 were also significantly higher than at T1 (T3 vs T1: 18.9 ± 3.6 mmHg vs 10.5 ± 2.8 mmHg, P < 0.001; T4 vs T1: 13.3 ± 3.7 mmHg vs 10.5 ± 2.8 mmHg, P < 0.001). However, no significant differences were observed for the haemodynamic and respiratory variables at any time point.

CONCLUSION

Our findings indicate that the intraoperative neck extension position during palatoplasty significantly increases IOP in paediatric cleft palate patients undergoing a palatoplasty.

Neck Extension and Intraocular Pressure Elevation During Palatoplasty in a Patient with Patau Syndrome and Congenital Glaucoma: A Case Report

Patau syndrome (trisomy 13) is a severe disorder associated with multiple systemic defects. Patau syndrome is commonly associated with ocular abnormalities but rarely associated with congenital glaucoma. To obtain a better surgical view, palatoplasty requires neck extension during surgery. The intraocular pressure (IOP) of patients with Patau syndrome can increase owing to the neck extension position while undergoing palatoplasty, particularly in those with congenital glaucoma. Here, we describe a case with increased IOP measured using a rebound tonometer during palatoplasty in a pediatric patient with Patau syndrome and congenital glaucoma. This case shows that it may be important to reduce the degree of neck extension and shorten the operation time to minimize any increase in the IOP during palatoplasty in pediatric patients with Patau syndrome accompanied by congenital glaucoma.

Ultrasound measurement of the optic nerve sheath diameter in traumatic brain injury: a narrative review

Background : Raised intracranial pressure (ICP) needs to be investigated in various situations, especially in traumatic brain injury (TBI). Ultra-sonographic (US) measurement of the optic nerve sheath diameter (ONSD) is a promising noninvasive tool for assessing elevated ICP. Objectives : This narrative review aimed to explain the history of and indications forUS measurement of ONSD. We focused on the detection of elevated ICP after TBI and discussed the possible improvements in detection methods. Conclusions : US measurement of ONSD in TBI cases provides a qualitative but no quantitative assessment of ICP. Current studies usually calculate their own optimum cutoff value for detecting raised ICP based on the balance between sensitivity and specificity of the method when compared with invasive methods. There is no universally accepted threshold. We did not find any paper focusing on the prognosis of patients benefiting from it when compared with usual care. Another limitation is the lack of standardization. US measurement of ONSD cannot be used as the sole technique to detect elevated ICP and monitor its evolution, but it can be a useful tool in a multimodal protocol and it might help to determine the prognosis of patients in various situations.

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.