Sage Journals: Discover world-class research

Abstract

BACKGROUND:

Most portable bi-level positive airway pressure devices are not equipped with air-oxygen blenders for precisely regulating oxygen concentrations, and supplemental oxygen must be added to increase the F_IO₂. Very few studies have investigated the factors that affect F_IO₂, and their conclusions have been inconsistent. We investigated in vitro noninvasive ventilation (NIV) parameters and their effects on F_IO₂, particularly the effect of the oxygen injection site.

METHODS:

NIV was simulated with a test lung and manikin setup. F_IO₂ was measured with 4 oxygen injection sites (mask, in front of the exhalation valve, at the humidifier outlet, and proximal to the ventilator), with 3 exhalation valve types, with 2 oxygen flows, and with 4 combinations of inspiratory and expiratory pressure.

RESULTS:

Oxygen flow, inspiratory and expiratory pressure, and exhalation valve type all affected F_IO₂. For a given oxygen flow, the oxygen injection site was the most important factor that affected F_IO₂. The oxygen injection site that was closest to the patient (on the mask) had the higher F_IO₂ (P < .001).

CONCLUSIONS:

The oxygen injection site had the greatest effect on F_IO₂ during NIV.

Keywords

noninvasive ventilation respiratory flow oxygen injection site

Get full access to this article

View all access options for this article.

References

American Thoracic Society; European Respiratory Society; European Society of Intensive Care Medicine; Société de Réanimation de Langue Française. International consensus conferences in intensive care medicine: noninvasive positive pressure ventilation in acute respiratory failure. Am J Respir Crit Care Med, 2001; 163(1):283–291.

Nava

, Hill

. Non-invasive ventilation in acute respiratory failure. Lancet, 2009; 374(9685):250–259.

Ambrosino

, Vagheggini

. Noninvasive positive pressure ventilation in the acute care setting: where are we?. Eur Respir J, 2008; 31(4):874–886.

Kacmarek

. Noninvasive positive-pressure ventilation: the little things do make the difference!. Respir Care, 2003; 48(10):919–921.

Hess

. Noninvasive ventilation in neuromuscular disease: equipment and application. Respir Care, 2006; 51(8):896–912.

Ferreira

, Chipman

, Hill

, Kacmarek

. Bilevel vs ICU ventilators providing noninvasive ventilation: effect of system leaks: a COPD lung model comparison. Chest, 2009; 136(2):448–456.

Thys

, Liistro

, Dozin

, Marion

, Rodenstein

. Determinants of F_IO₂ with oxygen supplementation during noninvasive two-level positive pressure ventilation. Eur Respir J, 2002; 19(4):653–657.

Schwartz

, Kacmarek

, Hess

. Factors affecting oxygen delivery with bi-level positive airway pressure. Respir Care, 2004; 49(3):270–275.

Waugh

, De Kler

. Inspiratory time, pressure settings, and site of supplemental oxygen insertion affect delivered oxygen fraction with the Quantum PSV noninvasive positive pressure ventilator. Respir Care, 1999; 44(5):520–523.

10.

Zhang

, Wang

. Study of oxygen supply in non-invasive positive pressure ventilation therapy. Chin J Tuberculosis Respir Dis, 2004; 27:868–869. Article in Chinese.

11.

Szkulmowski

, Belkhouja

, Le

, Robert

, Argaud

. Bilevel positive airway pressure ventilation: factors influencing carbon dioxide rebreathing. Intensive Care Med, 2010; 36(4):688–691.

12.

Samolski

, Calaf

, Guell

, Casan

, Anton

. Carbon dioxide rebreathing in non-invasive ventilation. Analysis of masks, expiratory ports and ventilatory modes. Monaldi Arch Chest Dis, 2008; 69(3):114–118.