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LETTER TO EDITOR
Year : 2020  |  Volume : 68  |  Issue : 5  |  Page : 1248--1249

In Reply to the Response to Article “A Comparison of Hypertonic Saline (HTS) and Mannitol on Intraoperative Brain Relaxation in Patients with Raised Intracranial Pressure during Supratentorial Tumors Resection: A Randomized Control Trial”

Kiran Jangra1, Ankush Singla2, Preethy J Mathew1,  
1 Department of Anaesthesia and Intensive Care, Postgraduate Institute of Medical Education and Research, Chandigarh, India
2 Department of Anaesthesia, Adesh Medical College, Bhathinda, Punjab, India

Correspondence Address:
Dr. Kiran Jangra
Department of Anaesthesia and Intensive Care, 4th Floor, Nehru Hospital, Postgraduate Institute of Medical Education and Research, Chandigarh - 160 012
India




How to cite this article:
Jangra K, Singla A, Mathew PJ. In Reply to the Response to Article “A Comparison of Hypertonic Saline (HTS) and Mannitol on Intraoperative Brain Relaxation in Patients with Raised Intracranial Pressure during Supratentorial Tumors Resection: A Randomized Control Trial”.Neurol India 2020;68:1248-1249


How to cite this URL:
Jangra K, Singla A, Mathew PJ. In Reply to the Response to Article “A Comparison of Hypertonic Saline (HTS) and Mannitol on Intraoperative Brain Relaxation in Patients with Raised Intracranial Pressure during Supratentorial Tumors Resection: A Randomized Control Trial”. Neurol India [serial online] 2020 [cited 2021 Jan 23 ];68:1248-1249
Available from: https://www.neurologyindia.com/text.asp?2020/68/5/1248/299135


Full Text



Dear Editor,

This is the reply to the queries raised for the manuscript “A Comparison of Hypertonic Saline (HTS) and Mannitol on Intraoperative Brain Relaxation in Patients with Raised Intracranial Pressure during Supratentorial Tumors Resection: A Randomized Control Trial” authored by Singla et al. in Neurology India (Issue 68).[1]

Thank you for highlighting the important issues. The authors have very elaborately described the differences in the hypertonic saline (HTS) and mannitol, and shortcoming of the study conducted by Singla et al.[1] However, we would like to highlight a few points for the authors.

In the present study, we have mentioned near equimolar solutions as we were aware that these two agents have different osmolarity. The difference is not very large, and it is 1098 vs. 1024 for mannitol vs. HTS, respectively.

Regarding osmotic pressure, the book chapter[2] cited by the authors was written for the systemic circulation, not in context with brain parenchyma, and they have quoted osmotic pressure generated by serum albumin. In the brain, sodium plays a major role in determining the movement of fluid. Sometimes the theoretical or experimental data do not reflect in the clinical scenario. Both HTS and mannitol are considered under osmotherapy by enlarge, hence, we did not make any comment about difference in the osmotic pressure (OP). The difference is OP also favors the HTS, which is consistent with findings of the current study.

Regarding hyperchloremic metabolic acidosis (HCMA), theoretically, it may be a matter of concern but we did not find this complication in any of the patients in our study group. In a study quoted by the author's on HCMA, 7.5% HTS-dextran was used.[3] 7.5% HTS contains 1274 mMoles/L of sodium and chloride, whereas 3% HTS contains 513 mMoles/L of sodium and chloride. In the present study, we used 3% HTS, and hence we did not find any case of HCMA with a single bolus dose.

We agree that if there is a breach in the blood-brain barrier, the osmotherapy may paradoxically increase intracranial pressure (ICP). At the same time, it is also a routine practice of using decongestants in the patients with the features of raised ICP. In the current study, we included the patients with clinical or radiological features of raised ICP, where decongestive therapy is routinely given intraoperatively to provide a relaxed brain. In our study, we just included the large solid tumors, the cystic lesions were not included.

One of the major goals of intraoperative the management of neurosurgical patients is to prevent secondary brain injuries. As per ethical limitations, we did not allow the mean arterial pressure to fall below the clinically permissible range. It is mentioned in the results that none of the patients required additional treatments for the management of hypovolemia, other than intravenous fluid infusion. We agree that the data regarding total fluid volume used should have been mentioned here even though it was not significantly different amongst the groups.

In the present study, both mannitol and HTS were found to be equally efficacious in reducing intracranial hypertension, but mean arterial pressure and central venous pressure were better maintained close to the baseline with HTS. On these grounds we advocated the use of HTS over mannitol.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

References

1Singla A, Mathew PJ, Jangra K, Gupta SK, Soni SL. A comparison of hypertonic saline and mannitol on intraoperative brain relaxation in patients with raised intracranial pressure during supratentorial tumors resection: A randomized control trial. Neurol India 2020;68:141-5.
2Feher J. Plasma and red blood cells. In: Quantitative Human Physiology-An Introduction. Elsevier; 2012. p. 428-36.
3Bruegger D, Bauer A, Rehm M, Niklas M, Jacob M, Irlbeck M, et al. Effect of hypertonic saline dextran on acid-base balance in patients undergoing surgery of abdominal aortic aneurysm. Crit Care Med 2005,33:556-63.