High-Frequency Chest Wall Oscillation in Acute Respiratory Failure With Bronchial Hypersecretion: A Randomized Controlled Trial.

BACKGROUND

Airway secretion retention is common in patients with acute respiratory failure (ARF), particularly in those requiring noninvasive respiratory support (NIRS). High-frequency chest wall oscillation (HFCWO) may improve airway clearance but critical care evidence remains limited.

RESEARCH QUESTION: Does adding HFCWO to standard care improve clinical outcomes in patients with bronchial hypersecretion and ARF requiring NIRS?

STUDY DESIGN AND

METHODS

We conducted a single-center randomized controlled trial in a RICU. Patients with ARF requiring NIRS, including high-flow nasal cannula (HFNC) and/or noninvasive ventilation (NIV), bronchial hypersecretion, and ineffective cough (peak cough expiratory flow <270 L/min) were randomized 1:1 to HFCWO plus standard care or standard care alone. The primary endpoint was therapeutic bronchoscopy. Secondary endpoints included hospital length of stay (LOS), RICU-LOS, NIRS duration, endotracheal intubation and mortality. Outcomes were analyzed using unadjusted and adjusted models accounting for age, sex, and main cause of hospitalization.

RESULTS

Eighty-eight patients were enrolled (44 HFCWO, 44 control), with comparable baseline characteristics. Bronchoscopy was required in 6 patients (13.6%) versus 14 (31.8%) (unadjusted p=0.042); after adjustment the association did not retain statistical significance (adjusted OR 0.336, 95% CI 0.111-1.021; p=0.055). Secondary outcomes, analyzed without correction for multiple testing, are exploratory. Hospital stay (12 [10-15.5] vs 16.5 [13-21] days) and RICU stay (8 [7-10.5] vs 12 [9-17] days) were shorter, with adjusted reductions of 4.5 and 3.6 days. HFNC duration was shorter (6 [4-8] vs 9.5 [6-11.5] days) and remained significant after adjustment, whereas the reduction in NIV duration did not (adjusted p=0.166). No patient required intubation and mortality did not differ.

INTERPRETATION: In this exploratory trial, HFCWO did not significantly reduce the need for therapeutic bronchoscopy after adjustment. Associated reductions in LOS and HFNC duration are hypothesis-generating and require confirmation in adequately powered multicenter trials.

CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov: NCT05751707; Tuscany Ethics Committee (Protocol: 21987-10/17/2022).