uu.seUppsala University Publications
Change search
ReferencesLink to record
Permanent link

Direct link
Reduction in postoperative atelectasis by continuous positive airway pressure and low oxygen concentration after endotracheal extubation
Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Medicinska och farmaceutiska vetenskapsområdet, centrumbildningar mm, Centre for Clinical Research, County of Västmanland. Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences, Clinical Physiology.
Show others and affiliations
(English)Manuscript (preprint) (Other academic)
Abstract [en]

Background. Atelectasis is common during and after general anaesthesia. We hypothesized that a ventilation strategy using a combination of 1) continuous positive airway pressure (CPAP) or positive end-expiratory pressure (PEEP) and 2) a reduced end-expiratory oxygen fraction (FETO2) before commencing mask ventilation with CPAP after extubation would reduce the area of postoperative atelectasis.

Methods. Thirty patients were randomized into three groups. During induction and emergence, inspiratory oxygen fractions (FIO2) were 1.0 in the control group and 1.0 or 0.8 in the intervention groups. No CPAP/PEEP was used in the control group, whereas CPAP/PEEP of 6 cmH2O was used in the intervention groups. After extubation, FIO2 was set to 0.30 in the intervention groups and CPAP was applied via a facemask, aiming at a FETO2 < 0.30. Atelectasis was studied by computed tomography 25 min postoperatively.

Results. The median area of atelectasis was 5.2 cm2 (range 1.6–12.2 cm2) and 8.5 cm2 (3–23.1 cm2) in the groups given FIO2 1.0 with or without CPAP/PEEP, respectively. In the group given FIO2 0.8, in which 7 patients were ex- or current smokers, the median area of atelectasis was 8.2 cm2 (1.8–14.7 cm2). After correction for body mass index and age, the difference between the two groups given FIO2 1.0 was statistically significant (P = 0.016).

Conclusion. Compared with conventional ventilation, this ventilation strategy reduced the area of postoperative atelectasis in one of the intervention groups but not in the other group, which included a higher proportion of smokers.

Keyword [en]
Atelectasis, CPAP, PEEP, Oxygen fraction, Ventilation, General Anaesthesia, Smoking
National Category
Anesthesiology and Intensive Care
Research subject
URN: urn:nbn:se:uu:diva-209961OAI: oai:DiVA.org:uu-209961DiVA: diva2:660141
Available from: 2013-10-29 Created: 2013-10-29 Last updated: 2013-10-29

Open Access in DiVA

No full text

Search in DiVA

By author/editor
Edmark, Lennart
By organisation
Centre for Clinical Research, County of VästmanlandClinical PhysiologyDepartment of Medical Sciences
Anesthesiology and Intensive Care

Search outside of DiVA

GoogleGoogle Scholar
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Total: 225 hits
ReferencesLink to record
Permanent link

Direct link