Evaluation of performance of two high-frequency oscillatory ventilators using a model lung with a position sensor

• Published in: Journal of anesthesia 2010-12, Vol.24 (6), p.888-892
• Main Authors: Iguchi, Naoya, Hirao, Osamu, Uchiyama, Akinori, Mashimo, Takashi, Nishimura, Masaji, Fujino, Yuji
• Format: Article
• Language: English
• Subjects: Acute respiratory distress syndrome; Adult; Airway Resistance - physiology; Analysis; Anesthesiology; Critical Care Medicine; Emergency Medicine; High-Frequency Ventilation - standards; Humans; Intensive; Intubation, Intratracheal; Lung - physiology; Lung Volume Measurements; Measuring instruments; Medicine; Medicine & Public Health; Models, Anatomic; Original Article; Pain Medicine; Positive-Pressure Respiration; Pulmonary Disease, Chronic Obstructive - physiopathology; Respiratory Distress Syndrome, Adult - therapy; Sensors; Tidal Volume - physiology
• ISSN: 0913-8668; 1438-8359
• DOI: 10.1007/s00540-010-1032-0

Purpose High-frequency oscillatory ventilation (HFOV) is thought to protect the lungs of acute respiratory distress syndrome (ARDS) patients. The performance and mechanical characteristics of high-frequency oscillatory ventilators, especially with regard to delivering appropriate tidal volume ( V T ) to compromised lungs, might affect the outcome of patients. We evaluated the performance of two such ventilators using a model lung with a position sensor. Methods We tested the Metran R100 and SensorMedics 3100B. V T was measured using the model lung with the compliance set at 20 or 50 ml/cmH 2 O and the resistance at 0 or 20 cmH 2 O/l/s. Oscillator frequency was set at 5, 7, and 9 Hz, and amplitude was set at 25%, 50%, 75%, and 100% (100% being maximum amplitude available at each setting configuration). Results At each model lung setting, R100 delivered greater V T at 5 Hz. V T differences between the ventilators decreased as frequency increased and were negligible at 9 Hz. At each model lung setting and frequency, as amplitude increased from 25% to 100%, V T increased proportionally more with R100. With an I:E ratio of 1:1, 3100B delivered greater V T than with 1:2. Conclusion Because it is able to deliver comparably greater V T , R100 may be a better choice for HFOV in critical ARDS patients. Better proportionality may be a result of more effective amplitude titration for adjusting PaCO 2 during oscillation.