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Influence of Two Different Interfaces for Noninvasive Ventilation Compared to Invasive Ventilation on the Mechanical Properties and Performance of a Respiratory System: Wasted Efforts
Racca et al recently studied the effectiveness of the helmet in a human model of resistive breathing, finding a higher inspiratory effort if the helmet was used compared to the face mask. In line with our data (Fig 5), the less effective unloading of the respiratory muscles in NIV-H was partially explained by the underassistance […]
Influence of Two Different Interfaces for Noninvasive Ventilation Compared to Invasive Ventilation on the Mechanical Properties and Performance of a Respiratory System: Inspiratory Effort
With a helmet, the use of PS decreased delay times significantly, whereas this effect was relatively small during NIV-FM or invasive ventilation. These results suggest that the highest PEEP and PS levels clinically indicated and tolerated by the patient should be used when NIV with a helmet is used in order to enhance the trigger […]
Influence of Two Different Interfaces for Noninvasive Ventilation Compared to Invasive Ventilation on the Mechanical Properties and Performance of a Respiratory System: Technical Aspects
The performance of our modern ICU ventilator was significantly affected by the use of a helmet designed for NIV because delay times were more than twice as long with a helmet compared to a face mask or invasive ventilation. The level of PS and CPAP had a major effect on delay times when a helmet […]
Influence of Two Different Interfaces for Noninvasive Ventilation Compared to Invasive Ventilation on the Mechanical Properties and Performance of a Respiratory System: PTPs
During PS, the time course of Paw differed not only during the trigger phase but also later during pressurization (Fig 4). A rapid increase of Paw occurred after the trigger delay during NIV-FM and invasive ventilation, whereas this increase in Paw occurred more slowly during NIV-H. Consequently, PTP was slightly lower during the first 250 […]
Influence of Two Different Interfaces for Noninvasive Ventilation Compared to Invasive Ventilation on the Mechanical Properties and Performance of a Respiratory System: Delay Times
The second chamber, representing the “lung,” was connected to the tested ventilator (Evita 4; Drager Medical). The lung is passively displaced when the driving chamber is inflated by the ventilator. The following settings were studied: (1) RRs of10, 20, 30, and 40 breaths per minute; (2) PS levels raised in 1 cm H2O steps every […]
Influence of Two Different Interfaces for Noninvasive Ventilation Compared to Invasive Ventilation on the Mechanical Properties and Performance of a Respiratory System: Measurements of Time Delay
To simulate spontaneous breathing, we used a modified lung model (LS1500; Drager Medical). This lung model consists of an electrically driven pneumatic lung simulator that allows the adjustment of tidal volume, RR, compliance, and resistance. To analyze the effect of the different interfaces on trigger sensitivity, effort, and the resulting PTPs, we defined three phases […]
Influence of Two Different Interfaces for Noninvasive Ventilation Compared to Invasive Ventilation on the Mechanical Properties and Performance of a Respiratory System: Equipment
CPAP and NPSV were performed with a helmet (Starmed Castar R; Mirandola; Modena, Italy) or a face mask (King Systems Corporation; Noblesville, IN) put on a glass head that was connected to a lung model (Fig 1). The Castar R Helmet (size medium) has an internal volume of 7.5 L with inflated cuffs. When the […]