Airway closure: demonstration by breathing 100 percent O2 at low lung volumes and by N2 washout.

Bürger, Erich; Macklem, Peter T.

doi:10.1152/jappl.1968.25.2.139

Cited by 154 publications

(69 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…1). CV reflects airway closure occurring preferentially in dependent lung regions and peripheral airway obstruction [81,86,87]. Relative merits of these indices have been reviewed elsewhere [88].…”

Section: Trapped Gas Volumementioning

confidence: 99%

Consensus statement for inert gas washout measurement using multiple- and single- breath tests

Robinson¹,

Latzin²,

Verbanck³

et al. 2013

Eur Respir J

681

1,007

View full text Add to dashboard Cite

Inert gas washout tests, performed using the single-or multiple-breath washout technique, were first described over 60 years ago. As measures of ventilation distribution inhomogeneity, they offer complementary information to standard lung function tests, such as spirometry, as well as improved feasibility across wider age ranges and improved sensitivity in the detection of early lung damage. These benefits have led to a resurgence of interest in these techniques from manufacturers, clinicians and researchers, yet detailed guidelines for washout equipment specifications, test performance and analysis are lacking. This manuscript provides recommendations about these aspects, applicable to both the paediatric and adult testing environment, whilst outlining the important principles that are essential for the reader to understand. These recommendations are evidence based, where possible, but in many places represent expert opinion from a working group with a large collective experience in the techniques discussed.Finally, the important issues that remain unanswered are highlighted. By addressing these important issues and directing future research, the hope is to facilitate the incorporation of these promising tests into routine clinical practice.

show abstract

Section: Trapped Gas Volumementioning

confidence: 99%

Consensus statement for inert gas washout measurement using multiple- and single- breath tests

Robinson¹,

Latzin²,

Verbanck³

et al. 2013

Eur Respir J

681

1,007

View full text Add to dashboard Cite

show abstract

“…First, as shown by Kumar et al (3) when PEEP is discontinued abruptly, arterial Po2 falls sharply within 1 min. Small airway closure (19) with subsequent absorption of trapped gas and atelectasis (20) may explain the subsequent, more gradual diminution in Pao2.…”

Section: Discussionmentioning

confidence: 99%

Ventilation with end-expiratory pressure in acute lung disease

Falke¹,

Pontoppidan²,

Kumar³

et al. 1972

J. Clin. Invest.

375

104

View full text Add to dashboard Cite

show abstract

“…2 comparison with the pre-operative values, having returned almost to normal by the fifth day. However, there was no significant difference in Pao2 between the groups on any of the days on which measurements were made.…”

Section: Resultsmentioning

confidence: 73%

Postoperative pulmonary function

Da¹,

Aa²,

Smith³

1977

Anaesthesia

View full text Add to dashboard Cite

Absorption collapse of alveoli may develop if partial or complete occlusion of the airways occurs during the inhalation of 100% oxygen. 1--3 In addition, it has been suggested, on theoretical grounds, that alveoli with 'critical' v/Q ratios may collapse with only modest increases in the inspired oxygen c~ncentration.~ It is known that a reduction in functional residual capacity (FRC) occurs during anaesthesias* and it has beer, postulated' that this is associated with an increase in the number of closed airways, resulting in an increase in maldistribution of the inspired gas in relation to the pulmonary capillary blood flow.Nitrous oxide is a more soluble gas than nitrogen and there may be a greater tendency for absorption collapse to occur when oxygen1 nitrous oxide mixtures, as compared with oxygenlnitrogen mixtures, are inspired. It is known that the absorption collapse occurring as a result of breathing 100% oxygen at residual volume does not resolve for at least 14 hours' so it is likely that if collapse occurs in association with nitrous oxide anaesthesia, its effects may continue at least until the day after operation.This study compares the relative influence of nitrogenloxygen and nitrous oxideloxygen mixtures, inspired during anaesthesia, on Pao2, FRC and other subdivisions of lung volume in the immediate postoperative period. Patients and methods48 patients aged between 20 and 65 years, undergoing either vagotomy and pyloroplasty or cholecystectomy, were allocated randomly to two groups. One group was ventilated during anaesthesia with a mixture of 30% oxygen in nitrogen (N2 group), the other received nitrous oxide in place of nitrogen (NzO group).Patients of both sexes in the age range 21-65 years and within 10% of the normal weight range were admitted to the study. Apart from the reasons for surgery, the patients were healthy. Informed consent was obtained from each patient before the study commenced. Lung function tests were performed on the day before operation and on the lst, 2nd and 5th days after operation. At all times during the measurements, the patients lay in a standard semirecumbent position in the laboratory.Arterial blood was withdrawn from the radial artery into heparinised plastic syringes. Pao2, Pacoz and pH were measured immediately using appropriate Radiometer electrodes. A blood-gas factor (1,065) was applied to the measured Po2 of blood to allow for the difference between the response of the electrode to air and blood. Using the Severinghaus slide rule," blood-gas values were corrected for the difference in temperatures between the electrodes, which were maintained at 37WC, and the patient's core temperature. The alveolar-arterial oxygen partial pressure difference (PAo~ -Paoz) was calculated as:(Pro, -Pacoz) R -Pa0 P A O~-P~~Z =

show abstract

Airway closure: demonstration by breathing 100 percent O2 at low lung volumes and by N2 washout.

Cited by 154 publications

References 0 publications

Consensus statement for inert gas washout measurement using multiple- and single- breath tests

Consensus statement for inert gas washout measurement using multiple- and single- breath tests

Ventilation with end-expiratory pressure in acute lung disease

Postoperative pulmonary function

Contact Info

Product

Resources

About