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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-10071-24665
Letter to the Editor
Parasternal Intercostal Muscle Thickness Fraction (PICTF%): Ultrasound a New Tool for Weaning Prediction?
Bhattacharya Dipasri 1https://orcid.org/0000-0002-9001-1525

Esquinas Antonio M 2https://orcid.org/0000-0003-0571-2050

Mandal Mohanchandra 3https://orcid.org/0000-0003-4183-993X

1 Department of Anaesthesiology, R. G. Kar Medical College and Hospital, Kolkata, West Bengal, India
2 Department of Intensive Care Unit, Hospital General Universitario Morales Meseguer, Murcia, Spain
3 Department of Anesthesiology, Institute of Post Graduate Medical Education & Research, Kolkata, West Bengal, India
Mohanchandra Mandal, Department of Anesthesiology, Institute of Post Graduate Medical Education & Research, Kolkata, West Bengal, India, Phone: +91 9433072820, e-mail: drmcmandal@gmail.com
4 2024
30 3 2024
28 4 404404
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: Bhattacharya D, Esquinas AM, Mandal M. Parasternal Intercostal Muscle Thickness Fraction (PICTF%): Ultrasound a New Tool for Weaning Prediction? Indian J Crit Care Med 2024;28(4):404.

Keywords

Airway extubation
Coronavirus disease-19
Critical illness
Diaphragm
Intercostal muscles
Maximal respiratory pressures
Mechanical ventilation
Parasternal intercostal muscle thickness
Respiratory rate
Ventilators
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pmc Dear Editor,

We have read the article of Ramaswamy et al.1 with great interest. The authors observed that assessing the thickness fraction of parasternal intercostal muscle (PICTF%) can predict adequately weaning failure. However, we raise certain points for further clarification of their reported observation.

First, it is not clear whether they have included coronavirus disease-19 (COVID-19) patients who often require mechanical ventilation. Parasternal intercostal muscle thickness fraction evaluated within 12 hours of admission in patients with severe COVID-19 can accurately predict not only the need for ventilator support but also the outcome and 30-day mortality.2

Second, the PICTF% shows increased activity as a compensatory mechanism for reduced activity of the diaphragm. The PICTF% can independently predict failure of the weaning trial, especially in patients with normal thickness of the diaphragm.3 It would have been great if the authors could have measured the excursion of the diaphragm to evaluate its dysfunction. Moreover, combined use of PICTF% and airway occlusion pressure measured at 100 milliseconds can predict weaning failure.4 Composite indicators such as the CROP index and rapid shallow breathing index (RSBI) are also useful predictors of weaning.3

Third, it is not evident how much inspiratory support the patients were receiving during ventilation. Excessive inspiratory support can lead to disuse atrophy of the diaphragm and intercostal muscles. Moreover, the deleterious effect of over-recruitment adds to the insult.5

We appreciate the authors’ work on the cut-off value of PICTF% to suggest its discriminating power and sensitivity in predicting extubation failure. This observation will throw light on the success of extubation after spontaneous breathing trials in critically ill patients.

Orcid

Dipasri Bhattacharya https://orcid.org/0000-0002-9001-1525

Antonio M Esquinas https://orcid.org/0000-0003-0571-2050

Mohanchandra Mandal https://orcid.org/0000-0003-4183-993X

Source of support: Nil

Conflict of interest: None
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References

1. Ramaswamy A Kumar R Arul M Ish P Madan M Gupta NK et al. Prediction of weaning outcome from mechanical ventilation using ultrasound assessment of parasternal intercostal muscle thickness Indian J Crit Care Med 2023 27 10 704 708 10.5005/jp-journals-10071-24548 37908421
2. Helmy MA Milad LM Hasanin AM Mostafa M Mannaa AH Youssef MM et al. Parasternal intercostal thickening at hospital admission: A promising indicator for mechanical ventilation risk in subjects with severe COVID-19 J Clin Monit Comput 2023 37 5 1287 1293 10.1007/s10877-023-00989-4 36961635
3. He G Han Y Zhan Y Yao Y Zhou H Zheng X The combined use of parasternal intercostal muscle thickening fraction and P0.1 for prediction of weaning outcomes Heart Lung 2023 62 122 128 10.1016/j.hrtlng.2023.07.002 37480723
4. Adolf Helmy M Magdy Milad L Hasanin A Mostafa M The novel use of diaphragmatic excursion on hospital admission to predict the need for ventilatory support in patients with coronavirus disease 2019 Anaesth Crit Care Pain Med 2021 40 6 100976 10.1016/j.accpm.2021.100976 34748940
5. Nakanishi N Oto J Ueno Y Nakataki E Itagaki T Nishimura M Change in diaphragm and intercostal muscle thickness in mechanically ventilated patients: A prospective observational ultrasonography study J Intensive Care 2019 7 56 10.1186/s40560-019-0410-4
