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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.

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Related in: MedlinePlus

Peak inspiratory flow of five of the ventilators tested. Measurements withpositive end-expiratory pressure of 5 cmH2O (PEEP5) and 10cmH2O (PEEP10) are on the left and right sides, respectively. Themeasurements were taken at pressure support levels of 5, 10, and 15cmH2O (PS5, PS10, and PS15, respectively). *The Horus ventilatorat PEEP5 and the e500 ventilator at PEEP10 were not measured due toautotriggering. #Because of the limitation of the lung model, the Velaventilator was not tested for PEEP10 with PS15.
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f04: Peak inspiratory flow of five of the ventilators tested. Measurements withpositive end-expiratory pressure of 5 cmH2O (PEEP5) and 10cmH2O (PEEP10) are on the left and right sides, respectively. Themeasurements were taken at pressure support levels of 5, 10, and 15cmH2O (PS5, PS10, and PS15, respectively). *The Horus ventilatorat PEEP5 and the e500 ventilator at PEEP10 were not measured due toautotriggering. #Because of the limitation of the lung model, the Velaventilator was not tested for PEEP10 with PS15.

Mentions: The PIF values increased in parallel with increases in inspiratory pressures (Figure 4), and the volume of leaks increased inparallel with increases in PEEP and pressure support. The mean values of PIF for allventilators were 1.69 ± 0.31 L/s, 2.07 ± 0.26 L/s, and 2.36 ± 0.31 L/s, respectively, atPS5, PS10, and PS15. The highest PIFs were reached by the BiPAP Vision and e500 (2.39 ±0.32 L/s and 2.14 ± 0.32 L/s, respectively). The Servo-i and the Vela ventilators hadintermediate values (2.00 ± 0.32 L/s and 1.82 ± 0.33 L/s, respectively), and thesmallest PIFs were attained by the Horus (1.60 ± 0.29 L/s).


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)

Peak inspiratory flow of five of the ventilators tested. Measurements withpositive end-expiratory pressure of 5 cmH2O (PEEP5) and 10cmH2O (PEEP10) are on the left and right sides, respectively. Themeasurements were taken at pressure support levels of 5, 10, and 15cmH2O (PS5, PS10, and PS15, respectively). *The Horus ventilatorat PEEP5 and the e500 ventilator at PEEP10 were not measured due toautotriggering. #Because of the limitation of the lung model, the Velaventilator was not tested for PEEP10 with PS15.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

f04: Peak inspiratory flow of five of the ventilators tested. Measurements withpositive end-expiratory pressure of 5 cmH2O (PEEP5) and 10cmH2O (PEEP10) are on the left and right sides, respectively. Themeasurements were taken at pressure support levels of 5, 10, and 15cmH2O (PS5, PS10, and PS15, respectively). *The Horus ventilatorat PEEP5 and the e500 ventilator at PEEP10 were not measured due toautotriggering. #Because of the limitation of the lung model, the Velaventilator was not tested for PEEP10 with PS15.
Mentions: The PIF values increased in parallel with increases in inspiratory pressures (Figure 4), and the volume of leaks increased inparallel with increases in PEEP and pressure support. The mean values of PIF for allventilators were 1.69 ± 0.31 L/s, 2.07 ± 0.26 L/s, and 2.36 ± 0.31 L/s, respectively, atPS5, PS10, and PS15. The highest PIFs were reached by the BiPAP Vision and e500 (2.39 ±0.32 L/s and 2.14 ± 0.32 L/s, respectively). The Servo-i and the Vela ventilators hadintermediate values (2.00 ± 0.32 L/s and 1.82 ± 0.33 L/s, respectively), and thesmallest PIFs were attained by the Horus (1.60 ± 0.29 L/s).

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