
==== Front
Indian J Crit Care Med
Indian J Crit Care Med
IJCCM
Indian Journal of Critical Care Medicine : Peer-reviewed, Official Publication of Indian Society of Critical Care Medicine
0972-5229
1998-359X
Jaypee Brothers Medical Publishers

10.5005/jp-journals-10071-24619
Letter to the Editor
Author Response
Niyogi Subhrashis Guha 1https://orcid.org/0000-0002-1146-1254

Naskar Chandrima 2https://orcid.org/0000-0002-0177-7618

Singh Avneet 3https://orcid.org/0000-0001-8593-4301

Kumar Bhupesh 4https://orcid.org/0000-0002-3118-0687

Grover Sandeep 5https://orcid.org/0000-0002-2714-2055

1,3,4 Department of Anaesthesia and Intensive Care, Postgraduate Institute of Medical Education and Research, Chandigarh, India
2,5 Department of Psychiatry, Postgraduate Institute of Medical Education and Research, Chandigarh, India
Chandrima Naskar, Department of Psychiatry, Postgraduate Institute of Medical Education and Research, Chandigarh, India, Phone: +91 9163718025, e-mail: cnbondhu@gmail.com
2 2024
29 1 2024
28 2 188188
Copyright © 2024; The Author(s).
2024
https://creativecommons.org/licenses/by-nc/4.0/ © The Author(s). 2024 Open Access. This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (https://creativecommons.org/licenses/by-nc/4.0/), which permits unrestricted use, distribution, and non-commercial reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.
How to cite this article: Niyogi SG, Naskar C, Singh A, Kumar B, Grover S. Author Response. Indian J Crit Care Med 2024;28(2):188.

Keyword

Cognitive dysfunction
Delirium
Melatonin
Post-cardiac surgery
==== Body
pmc Dear Editor,

Drs Suresh and Magoon have raised really pertinent points in their discussion of the index meta-analysis.1,2 As rightly pointed out by them, assessment of preoperative cognitive function can control for a major potential covariate in the causation of postoperative delirium.3 However, as they demonstrate with an informative table, trials actually measuring and reporting it are very few. Further, in the two trials objectively screening preoperative cognition, patients with observed deficits were excluded. Poor preoperative cognitive reserve is an important risk factor for postoperative delirium.4 Exclusion of this high-risk cohort leaves aside the patients with the highest possible benefit from pharmacological prevention of postoperative delirium. Hence, it is our opinion that objective documentation of preoperative cognitive reserve is important, but the exclusion of patients with preoperative cognitive deficits runs the risk of overestimating the treatment effect of the intervention pragmatically. Moreover, the current paucity of trials assessing cognition makes evidence synthesis including only trials with preoperative cognitive assessment unfeasible.

Secondly, on-pump and off-pump surgeries constitute two distinct pathophysiology of cerebral insult.5 Thus, they should be dealt with separately, and such a subgroup analysis was planned. However, as demonstrated in the table, studies reporting the primary outcome exclusively in the off-pump subgroup were very less, precluding a sufficiently powered analysis.

We welcome the points raised by Drs Suresh and Magoon, as they further expose the paucity of quality evidence about pharmacological neuroprotection in the perioperative milieu of cardiac surgeries, as well as the lack of standardized and clinically relevant interventions, outcomes, and management. This underlines the need for more high-quality trials using standardized interventions and outcomes in high-risk cohorts as recommended in our index study.

Orcid

Subhrashis Guha Niyogi https://orcid.org/0000-0002-1146-1254

Chandrima Naskar https://orcid.org/0000-0002-0177-7618

Avneet Singh https://orcid.org/0000-0001-8593-4301

Bhupesh Kumar https://orcid.org/0000-0002-3118-0687

Sandeep Grover https://orcid.org/0000-0002-2714-2055

Source of support: Nil

Conflict of interest: None
==== Refs
References

1. Suresh V Magoon R Post-cardiac surgery delirium: When the details matter! Indian J Crit Care Med 2024 28 2 185 187 38323256
2. Niyogi SG Naskar C Singh A Kumar B Grover S Melatonin and melatonin agonists for prevention of delirium in the cardiac surgical ICU: A meta-analysis Indian J Crit Care Med 2023 27 11 837 844 10.5005/jp-journals-10071-24571 37936806
3. Magoon R Mahajan S Jose J DEX, Delirium and Dilemma Braz J Cardiovasc Surg 2023 38 2 305 308 10.21470/1678-9741-2022-0002 36459474
4. Megari K Kosmidis M Protecting the brain while healing hearts: The protective role of cognitive reserve in Cardiac Surgery Am J Geriatr Psychiatry 2023 S1064 S7481 23 00448–7 10.1016/j.jagp.2023.10.003
5. Miyazaki S Yoshitani K Miura N Irie T Inatomi Y Ohnishi Y et al. Risk factors of stroke and delirium after off-pump coronary artery bypass surgery Interact Cardiovasc Thorac Surg 2010 12 3 379 383 10.1510/icvts.2010.248872 21148261
