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Performance of ICU ventilators during noninvasive ventilation with large leaks in a total face mask: a bench study.

Nakamura MA, Costa EL, Carvalho CR, Tucci MR - J Bras Pneumol (2014 May-Jun)

Bottom Line: The variables analyzed were ventilation trigger, cycling off, total leak, and pressurization.Of the eight ICU ventilators tested, four did not work (autotriggering or inappropriate turning off due to misdetection of disconnection); three worked with some problems (low PEEP or high cycling delay); and one worked properly.The majority of the ICU ventilators tested were not suitable for NIV with a leaky TFM.

View Article: PubMed Central - PubMed

Affiliation: Heart Institute, Hospital das Clínicas, School of Medicine, University of São Paulo, São Paulo, Brazil.

ABSTRACT

Objective: Discomfort and noncompliance with noninvasive ventilation (NIV) interfaces are obstacles to NIV success. Total face masks (TFMs) are considered to be a very comfortable NIV interface. However, due to their large internal volume and consequent increased CO2 rebreathing, their orifices allow proximal leaks to enhance CO2 elimination. The ventilators used in the ICU might not adequately compensate for such leakage. In this study, we attempted to determine whether ICU ventilators in NIV mode are suitable for use with a leaky TFM.

Methods: This was a bench study carried out in a university research laboratory. Eight ICU ventilators equipped with NIV mode and one NIV ventilator were connected to a TFM with major leaks. All were tested at two positive end-expiratory pressure (PEEP) levels and three pressure support levels. The variables analyzed were ventilation trigger, cycling off, total leak, and pressurization.

Results: Of the eight ICU ventilators tested, four did not work (autotriggering or inappropriate turning off due to misdetection of disconnection); three worked with some problems (low PEEP or high cycling delay); and one worked properly.

Conclusions: The majority of the ICU ventilators tested were not suitable for NIV with a leaky TFM.

Show MeSH

Related in: MedlinePlus

Measured positive end-expiratory pressure (PEEP; left panel) and expiratoryflow delivered by the ventilator (right panel) to compensate for air leakage atPEEP of 5 cmH2O (PEEP5) and 10 cmH2O (PEEP10), expressedas mean ± SD. As shown, the Horus and the e500 ventilators did not compensateadequately for leaks, delivering less than 0.6 L/s of compensatory flow, andwere not capable of keeping the set PEEP level. *Not measured due toautotriggering.
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f02: Measured positive end-expiratory pressure (PEEP; left panel) and expiratoryflow delivered by the ventilator (right panel) to compensate for air leakage atPEEP of 5 cmH2O (PEEP5) and 10 cmH2O (PEEP10), expressedas mean ± SD. As shown, the Horus and the e500 ventilators did not compensateadequately for leaks, delivering less than 0.6 L/s of compensatory flow, andwere not capable of keeping the set PEEP level. *Not measured due toautotriggering.

Mentions: Regarding PEEP and expiratory leakage, the Servo-i, Vela, and BiPAP Vision compensatedfor the TFM leaks during exhalation, maintaining PEEP values close to the set values(Figure 2). The mean flows delivered by theseventilators in order to compensate for leaks during exhalation were 0.65 ± 0.12 L/s and0.89 ± 0.16 L/s for PEEP5 and PEEP10, respectively. The e500 and Horus compensated forthe leakage poorly and therefore were not able to maintain the target PEEP (Figure 2). The maximum leakage-compensation flows forthe e500 and Horus were, respectively, 0.52 ± 0.01 L/s (PEEP5 with leakage compensationoption switched on) and 0.41 ± 0.01 L/s (PEEP10).


Performance of ICU ventilators during noninvasive ventilation with large leaks in a total face mask: a bench study.

Nakamura MA, Costa EL, Carvalho CR, Tucci MR - J Bras Pneumol (2014 May-Jun)

Measured positive end-expiratory pressure (PEEP; left panel) and expiratoryflow delivered by the ventilator (right panel) to compensate for air leakage atPEEP of 5 cmH2O (PEEP5) and 10 cmH2O (PEEP10), expressedas mean ± SD. As shown, the Horus and the e500 ventilators did not compensateadequately for leaks, delivering less than 0.6 L/s of compensatory flow, andwere not capable of keeping the set PEEP level. *Not measured due toautotriggering.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4109202&req=5

f02: Measured positive end-expiratory pressure (PEEP; left panel) and expiratoryflow delivered by the ventilator (right panel) to compensate for air leakage atPEEP of 5 cmH2O (PEEP5) and 10 cmH2O (PEEP10), expressedas mean ± SD. As shown, the Horus and the e500 ventilators did not compensateadequately for leaks, delivering less than 0.6 L/s of compensatory flow, andwere not capable of keeping the set PEEP level. *Not measured due toautotriggering.
Mentions: Regarding PEEP and expiratory leakage, the Servo-i, Vela, and BiPAP Vision compensatedfor the TFM leaks during exhalation, maintaining PEEP values close to the set values(Figure 2). The mean flows delivered by theseventilators in order to compensate for leaks during exhalation were 0.65 ± 0.12 L/s and0.89 ± 0.16 L/s for PEEP5 and PEEP10, respectively. The e500 and Horus compensated forthe leakage poorly and therefore were not able to maintain the target PEEP (Figure 2). The maximum leakage-compensation flows forthe e500 and Horus were, respectively, 0.52 ± 0.01 L/s (PEEP5 with leakage compensationoption switched on) and 0.41 ± 0.01 L/s (PEEP10).

Bottom Line: The variables analyzed were ventilation trigger, cycling off, total leak, and pressurization.Of the eight ICU ventilators tested, four did not work (autotriggering or inappropriate turning off due to misdetection of disconnection); three worked with some problems (low PEEP or high cycling delay); and one worked properly.The majority of the ICU ventilators tested were not suitable for NIV with a leaky TFM.

View Article: PubMed Central - PubMed

Affiliation: Heart Institute, Hospital das Clínicas, School of Medicine, University of São Paulo, São Paulo, Brazil.

ABSTRACT

Objective: Discomfort and noncompliance with noninvasive ventilation (NIV) interfaces are obstacles to NIV success. Total face masks (TFMs) are considered to be a very comfortable NIV interface. However, due to their large internal volume and consequent increased CO2 rebreathing, their orifices allow proximal leaks to enhance CO2 elimination. The ventilators used in the ICU might not adequately compensate for such leakage. In this study, we attempted to determine whether ICU ventilators in NIV mode are suitable for use with a leaky TFM.

Methods: This was a bench study carried out in a university research laboratory. Eight ICU ventilators equipped with NIV mode and one NIV ventilator were connected to a TFM with major leaks. All were tested at two positive end-expiratory pressure (PEEP) levels and three pressure support levels. The variables analyzed were ventilation trigger, cycling off, total leak, and pressurization.

Results: Of the eight ICU ventilators tested, four did not work (autotriggering or inappropriate turning off due to misdetection of disconnection); three worked with some problems (low PEEP or high cycling delay); and one worked properly.

Conclusions: The majority of the ICU ventilators tested were not suitable for NIV with a leaky TFM.

Show MeSH
Related in: MedlinePlus