Indian Journal of Critical Care Medicine
Volume 28 | Issue 2 | Year 2024

Author Response

Subhrashis Guha Niyogi1https://orcid.org/0000-0002-1146-1254, Chandrima Naskar2https://orcid.org/0000-0002-0177-7618, Avneet Singh3https://orcid.org/0000-0001-8593-4301, Bhupesh Kumar4https://orcid.org/0000-0002-3118-0687, Sandeep Grover5https://orcid.org/0000-0002-2714-2055

1,3,4Department of Anaesthesia and Intensive Care, Postgraduate Institute of Medical Education and Research, Chandigarh, India

2,5Department of Psychiatry, Postgraduate Institute of Medical Education and Research, Chandigarh, India

Corresponding Author: Chandrima Naskar, Department of Psychiatry, Postgraduate Institute of Medical Education and Research, Chandigarh, India, Phone: +91 9163718025, e-mail: cnbondhu@gmail.com

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.

Source of support: Nil

Conflict of interest: None

Keywords: Cognitive dysfunction, Delirium, Melatonin, Post-cardiac surgery.

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.


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


1. Suresh V, Magoon R. Post-cardiac surgery delirium: When the details matter! Indian J Crit Care Med 2024;28(2):185–187.

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. DOI: 10.5005/jp-journals-10071-24571.

3. Magoon R, Mahajan S, Jose J. DEX, Delirium and Dilemma. Braz J Cardiovasc Surg 2023;38(2):305–308. DOI: 10.21470/1678-9741-2022-0002.

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. DOI: 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. DOI: 10.1510/icvts.2010.248872.

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