Objective
Study the impact of ultrasound-assessed diaphragmatic impairment (DI) on predicting need for invasive mechanical ventilation (IMV) in acute exacerbation of chronic obstructive pulmonary disease (AECOPD) patients treated by non-invasive ventilation (NIV).
Design
A prospective observational study.
Setting
Critical Care Units of Alexandria Main University Hospital.
Patients
75 adult AECOPD patients of both sexes according to sample size calculation.
Methods
Ultrasound was used to measure diaphragmatic thickness (DT), diaphragmatic thickness fraction (DTF) was calculated, and DI was diagnosed when fraction was less than 20%. Patients were treated by NIV. Switching to IMV was done after NIV failure. Primary outcome was value of DI to predict need for IMV after NIV failure. Secondary outcome was impact of DI on fate of patients.
Results
According to fate of NIV, patients were categorized into successful and failed NIV groups. DTF in both groups were ≥33–38% and ≤16–18%. DTF with a cut-off value of <26–29% on both sides was able to predict NIV failure with 96.67% sensitivity and 80–82.22% specificity. Days of MV and ICU stay were significantly lower in the successful NIV group, < 0.001. 28-day mortality was significantly less encountered in successful NIV group, = 0.018.
Conclusion
DTF was a good indicator of DI that could predict need for IMV after NIV failure in AECOPD patients with good sensitivity and moderate specificity. MV Days, ICU stay, and 28-day mortality were significantly higher in patients with DI who needed IMV.