Abstract
Excessive tracheobronchial secretions are crucial determinant of extubation failure in ICU patients. High-Frequency Chest Wall Oscillation (HFCWO) is a technique aimed at clearing deep secretions.
Aims: Assessing the effects of HFCWO on lung aeration in intubated patients.
Methods: We enrolled 42 patients, invasively ventilated (>48 hours) and without contraindications to HFCWO (VEST, Hillrom) and electrical impedance tomography (EIT) (PulmoVista, Draeger). Patients were grouped according to the amount of secretions (i.e. < or ≥2 bronchoaspiration/hour), and randomly assigned to receive or not a recruitment manoeuvres (RM). After placing EIT and HFCWO belts and obtaining a baseline record, we performed a 10-minute HFCWO session. After HFCWO, EIT records and arterial blood gases (ABGs) were obtained immediately, and 1 and 3 hours later, after closed suctioning and, in the randomized patients, application of RM. Changes in end-expiratory lung impedance (dEELI), a surrogate determination of end-expiratory lung volume, and tidal impedance variation (TIV) were computed.
Results: Overall, we observed no significant changes in dEELI (p=0.815) and TIV (p=0.549). In patients without hypersecretion (< bronchoaspiration/hour), HFCWO slightly and not significantly decreased dEELI (p=0.098), while TIV remained unchanged (p=0.252). In patients with hypersecretion, dEELI significantly increased (p=0.009), while TIV remained unchanged (p=0.165). RMs did not produce any significant changes in either dEELI or TIV. ABGs were also unmodified.
Conclusions: HFCWO improves dEELI in the patients with hypersecretion only, while it is ineffective in those without hypersecretion. RMs do not add benefit.
- Copyright ©the authors 2016