RT Journal Article
SR Electronic
T1 Involvement of Respiratory Muscles During the Timed Inspiratory Effort Index Measurement With Surface Electromyography
JF Respiratory Care
FD American Association for Respiratory Care
SP 1857
OP 1863
DO 10.4187/respcare.07465
VO 65
IS 12
A1 de Souza Costa, Helson Lino Leite
A1 de Souza, Leonardo Cordeiro
A1 da Silva Neto, Arthur Evangelista
A1 da Silva Guimarães, Bruno Leonardo
A1 de Azeredo, Leandro Miranda
A1 Godoy, Marcos David Parada
A1 Lugon, Jocemir Ronaldo
YR 2020
UL http://rc.rcjournal.com/content/65/12/1857.abstract
AB BACKGROUND: Mechanical ventilation is a life-support therapy that can be associated with respiratory muscle dysfunction that may perturb the weaning process. The timed inspiratory effort (TIE) index is a recently proposed weaning index that has been reported to be effective in predicting successful weaning. We sought to analyze the respiratory muscle groups involved with the TIE index measurement utilizing the surface electromyography (sEMG).METHODS: We conducted a prospective observational study including 46 mechanically ventilated subjects. The variable analyzed with sEMG was the root mean square (RMS) for correlation with the degree of recruitment of motor units and strength. The data were obtained along the 60 s of the TIE index measurement and analyzed in each one of the 3 20-s intervals. Pooled and individual muscle RMS values were analyzed comparing success and failure groups. P < .05 was considered significant.RESULTS: The median (interquartile range) age of the participants was 80 (71–87) y. The pooled sEMG data showed that muscle strength increased over time, following the profile observed for maximum inspiratory pressure, irrespective of the analyzed group. However, in line with the findings regarding maximum inspiratory pressure, the RMS medians were statistically higher at every 20-s interval in the success group. Diaphragm strength increased over time, with values reaching statistically significant differences at the end of the observation period, but only in the success group. In addition, diaphragm strength was statistically higher during the whole test in the success group. Finally, there was a substantial increase in sternocleidomastoid strength over time after 40 s of observation, which was not observed in the scalene muscles.CONCLUSIONS: Subjects succeeding in a weaning trial had higher muscle strength, confirmed in the pooled and the individual sEMG analysis. A vigorous diaphragm with low fatigue potential seems essential for successful weaning; the sternocleidomastoid may also be of importance in this regard.