Association between rectus femoris cross-sectional area and diaphragmatic excursion with weaning of tracheostomized patients in the intensive care unit.

Objective: To verify the relationship between the rectus femoris cross-sectional area and diaphragmatic excursion with successful weaning from mechanical ventilation in chronic critically tracheostomized patients.

Methods: This was a prospective observational cohort study. We included chronic critically ill patients (those who underwent tracheostomy placement after 10 days under mechanical ventilation). The rectus femoris cross-sectional area and diaphragmatic excursion were obtained by ultrasonography performed within the first 48 hours after tracheostomy. We measured rectus femoris cross-sectional area and diaphragmatic excursion to assess their association with weaning from mechanical ventilation, including their potential to predict successful weaning and survival throughout the intensive care unit stay.

Results: Eighty-one patients were included. Forty-five patients (55%) were weaned from mechanical ventilation. The mortality rates were 42% and 61.7% in the intensive care unit and hospital, respectively. The fail group in relation to the success group at weaning presented a lower rectus femoris cross-sectional area (1.4 [0.8] versus 1.84 [0.76]cm2, p = 0.014) and lower diaphragmatic excursion (1.29 ± 0.62 versus 1.62 ± 0.51cm, p = 0.019). When rectus femoris cross-sectional area ≥ 1.80cm2 and diaphragmatic excursion ≥ 1.25cm was a combined condition, it had a strong association with successful weaning (adjusted OR = 20.81, 95%CI 2.38 - 182.28; p = 0.006) but not with intensive care unit survival (adjusted OR = 0.19, 95%CI 0.03 - 1.08; p = 0.061).

Conclusion: Successful weaning from mechanical ventilation in chronic critically ill patients was associated with higher measurements of rectus femoris cross-sectional area and diaphragmatic excursion.