Prospective Study
Copyright ©The Author(s) 2017. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Crit Care Med. Nov 4, 2017; 6(4): 185-189
Published online Nov 4, 2017. doi: 10.5492/wjccm.v6.i4.185
Reproducibility of diaphragm thickness measurements by ultrasonography in patients on mechanical ventilation
Ashesh Dhungana, Gopi Khilnani, Vijay Hadda, Randeep Guleria
Ashesh Dhungana, Department of Medicine, National Academy of Medical Sciences, Pulmonary Medicine, Kantipath, Kathmandu 44600, Nepal
Gopi Khilnani, Vijay Hadda, Randeep Guleria, Department of Pulmonary Medicine and Sleep Disorders, All India Institute of Medical Sciences, New Delhi 110029, India
Author contributions: Dhungana A, Khilnani G and Hadda V are guarantors of the paper, be responsibility for the integrity of the work; Khilnani G and Hadda V conceived the idea; Dhungana A was involved in performing ultrasonography, data collection, manuscript drafting and revision; Hadda V contributed to performing ultrasonography, manuscript drafting and revision; Guleria R was involved in drafting and revising the manuscript.
Institutional review board statement: This study was reviewed and approved by institutional review board of All India Institute of Medical Sciences.
Informed consent statement: All study participants, or their legal guardian, provided written consent prior to enrollment into the study.
Conflict-of-interest statement: None of the authors have any conflict of interest.
Data sharing statement: There is no additional data available.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Correspondence to: Dr. Ashesh Dhungana, MD, DM, Assistant Professor, Department of Medicine, National Academy of Medical Sciences, Pulmonary Medicine, Kantipath, Kathmandu 44600, Nepal. nams@healthnet.org.np
Telephone: +977-98-41860457
Received: April 20, 2017
Peer-review started: April 21, 2017
First decision: July 18, 2017
Revised: July 26, 2017
Accepted: September 3, 2017
Article in press: September 4, 2017
Published online: November 4, 2017
Processing time: 195 Days and 7.8 Hours
Abstract
AIM

To prospectively evaluate the reproducibility of diaphragm thickness measurement by ultrasonography at the bedside by critical care physicians in patients on invasive mechanical ventilation.

METHODS

In a prospective observational study of 64 invasively ventilated patients, diaphragmatic thickness measurement was taken by 2 different observers at the same site. Three measurements were taken by each observer and averaged. The intraobserver and interobserver variability was assessed by estimation of intraclass correlation coefficient. The limits of agreement were plotted as the difference between two observations against the average of the two observations in Bland and Altman analysis.

RESULTS

The mean diaphragm thickness at the functional residual capacity was 2.29 ± 0.4 mm and the lower limit of the normal, i.e., the 5th percentile was 1.7 mm (95%CI: 1.6-1.8). The intraclass correlation coefficient for intraobserver variability was 0.986 (95%CI: 0.979-0.991) with a P value of < 0.001. The intraclass correlation coefficient for interobserver variability was 0.987 (95%CI: 0.949-0.997) with a P value of < 0.001. In Bland and Altman analysis, both intraobserver and interobserver measurements showed high limits of agreement.

CONCLUSION

Our study demonstrates that the measurement of diaphragm thickness by ultrasound can be accurately performed by critical care physicians with high degree of reproducibility in patients on mechanical ventilation.

Keywords: Diaphragm; Ultrasonography; Mechanical ventilation

Core tip: Ultrasonography (USG) is a cheap, cost effective and non-invasive bedside tool for evaluation of diaphragm thickness during mechanical ventilation. Measurement of diaphragm thickness by USG can be accurately performed by critical care physicians with high degree of reproducibility. USG should be used more often by the physicians in the intensive care unit for the assessment of the diaphragm.