Preliminary Evaluation of High-Frequency Chest Compression for Secretion Clearance in Mechanically Ventilated Patients

Abstract

BACKGROUND: A high-frequency chest compression (HFCC) device called the ThAIRapy System has been developed to provide secretion clearance therapy. We evaluated the safety, efficacy, and utility of the device in long-term mechanically ventilated patients. DESCRIPTION OF DEVICE: The primary com-ponents of the device are an air-pulse generator and an inflatable vest. Small gas volumes are alternately injected into and withdrawn from the vest by the air-pulse generator at a fast rate, creating an oscillatory or vibratory motion. The pulses cause the vest to inflate and deflate against the thorax of the patient. EVALUATION METHODS: We evaluated HFCC by comparing it to per-cussion and postural drainage therapy (P&PD); sputum production, patient com-fort (PC), pulse-oximetry saturation (SpO₂), heart rate (HR), and blood pressure (BP) data were collected and compared between the 2 methods. We monitored the reliability of the device and distributed a survey questionnaire to the entire respiratory therapy staff to assess utility. EVALUATION RESULTS: Nine pa-tients completed the safety and efficacy portion of our evaluation. No significant difference was found between P&PD and HFCC in the wet weight of collected sputum, the mean change-in-percent of SpO₂ or the mean percent change from baseline in HR, BP, or PC. All therapists believed that the ThAIRapy System was easy to learn, and 70% considered it an acceptable alternative to P&PD. Of the staff members surveyed, 80% believed that use of the HFCC device resulted in time savings in all or most cases. There were no equipment malfunctions in 225 hours of use. CONCLUSIONS: Compared to P&PD, HFCC via the ThAIRapy System may be equally efficacious in promoting secretion clearance in long-term mechanically ventilated patients. HFCC is neither more nor less safe for patients than is P&PD using SpO₂, HR, BP, and PC as outcome variables. Most of our res-piratory therapists perceived HFCC as an acceptable alternative to P&PD.