LETTER TO THE EDITOR |
https://doi.org/10.5005/jp-journals-10071-24209 |
Reply to Letter to Editor: Effect of Percutaneous Tracheostomy on Optic Nerve Sheath Diameter [TONS Trial]
Department of Neuroanaesthesiology and Critical Care, AIIMS, New Delhi, India
Corresponding Author: Indu Kapoor, Department of Neuroanaesthesiology and Critical Care, AIIMS, New Delhi, India, Phone: +91 9013439134, e-mail: dr.indu.me@gmail.com
How to cite this article: Kapoor I. Reply to Letter to Editor: Effect of Percutaneous Tracheostomy on Optic Nerve Sheath Diameter [TONS Trial]. Indian J Crit Care Med 2022;26(5):654.
Source of support: Nil
Conflict of interest: None
Keywords: Intracranial pressure, Optic nerve sheath diameter, Tracheostomy.
We thank Paola et al. for showing interest in our article and appreciate their keen observations.1 We welcome the comments made by them and will try answering to their satisfaction. Our response to their concerns is given below:
The study by Geng et al. is in patients undergoing laparoscopic surgery in Trendelenburg position where the head is lowered 45° along with pneumoperitoneum. They used propofol and sevoflurane anesthetic agents for the maintenance of anesthesia throughout the surgery.2 However, in our study, we used propofol only once at the beginning as a bolus dose @ 2 mg/kg to facilitate the procedure. Thereafter we took optic nerve sheath diameter (ONSD) measurements at different stages of percutaneous tracheostomy (PCT). Though the effect of propofol on ONSD cannot be denied, we feel that a single bolus may not have influenced the ONSD values as much as continuous infusion would have, as in the study by Geng et al.2
We agree with Paola et al. regarding their suggestion to use A-scan technique for similar studies in the future, which could possibly give more reliable findings. However, there are studies suggesting the reliability and good correlation between B-mode sonographic ONSD and invasive intracranial pressure measurements which are considered gold standard also.3,4
ORCID
Indu Kapoor https://orcid.org/0000-0002-3065-4940
REFERENCES
1. Kapoor I, Wanchoo J, Mahajan C, Singhal V, Roy H, Kumar S, et al. Effect of percutaneous tracheostomy on optic nerve sheath diameter [TONS trial]. Indian J Crit Care Med 2021;25(4):382–387. DOI: 10.5005/jp-journals-10071-23783.
2. Geng W, Chen C, Sun X, Huang S. Effects of sevoflurane and propofol on the optic nerve sheath diameter in patients undergoing laparoscopic gynecological surgery: a randomized controlled clinical studies. BMC Anesthesiol 2021;21(1):30. DOI: 10.1186/s12871-021-01243-7.
3. Kimerly HH, Shah S, Marill K, Noble V. Correlation of optic nerve sheath diameter with direct measurement of intracranial pressure. Acad Emerg Med 2008;15(2):201–204. DOI: 10.1111/j.1553-2712.2007.00031.x.
4. Geeraerts T, Merceron S, Benhamou D, Vigué B, Duranteau J. Non-invasive assessment of intracranial pressure using ocular sonography in neurocritical care patients. Intens Care Med 2008;34(11):2062–2067. DOI: 10.1007/s00134-008-1149-x.
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