• Br J Anaesth · Jan 2020

    Randomized Controlled Trial Comparative Study

    Effects of positive end-expiratory pressure/recruitment manoeuvres compared with zero end-expiratory pressure on atelectasis during open gynaecological surgery as assessed by ultrasonography: a randomised controlled trial.

    Intraoperative PEEP and recruitment manoeuvres reduce ultrasound-detected atelectasis intraoperatively but showed no post-extubation benefit after open gynaecological surgery.

    pearl
    • Vincent Généreux, Michaël Chassé, François Girard, Nathalie Massicotte, Carl Chartrand-Lefebvre, and Martin Girard.
    • Department of Anaesthesiology, Centre Hospitalier de l'Université de Montréal, Montreal, QC, Canada.
    • Br J Anaesth. 2020 Jan 1; 124 (1): 101-109.

    BackgroundDuring general anaesthesia, most patients develop atelectasis, which promotes postoperative pulmonary complications. RCTs that investigated perioperative lung protection have failed to reduce postoperative pulmonary complications consistently. Ultrasound imaging could help confirm the effects of different protective ventilatory strategies, but this has not been tested in trials. The objective of this study was to use ultrasonography to evaluate whether lung-protective ventilation measures reduce perioperative atelectasis.MethodsWe conducted a prospective, randomised patient- and assessor-blinded controlled trial in women undergoing open gynaecological surgery. Subjects were randomised to either lung protection or zero end-expiratory pressure (ZEEP; with no recruitment manoeuvres [RMs]). Lung protection entailed PEEP (7 cm H2O) and RMs every 30 min. Lung ultrasonography was undertaken at five predefined time points. The primary outcome was the difference in lung ultrasonography score (LUS) between groups before emergence; a lower LUS indicates better lung aeration.ResultsWe recruited 45 women (34-85 yr old). Women randomised to lung protection had lower mean (standard deviation) LUS before emergence (6.1 [3.7]), compared with women randomised to ZEEP (11.7 [3.9]; 95% confidence interval for the difference between group means [-7.9 to -3.2]; P<0.0001). This difference did not persist after extubation, with similar mean LUSs in women who had received intraoperative lung protection (7.0 [4.1]), compared with women randomised to receive ZEEP (7.7 [3.1]).ConclusionsAs assessed by lung ultrasonography, intraoperative PEEP/RMs decreased aeration loss during general anaesthesia. However, similar degrees of aeration loss were observed after tracheal extubation regardless of intraoperative ventilatory strategy.Clinical Trial RegistrationNCT02055807.Copyright © 2019 British Journal of Anaesthesia. Published by Elsevier Ltd. All rights reserved.

      Pubmed     Full text   Copy Citation  

      Add institutional full text...

    Notes

    pearl
    1

    Intraoperative PEEP and recruitment manoeuvres reduce ultrasound-detected atelectasis intraoperatively but showed no post-extubation benefit after open gynaecological surgery.

    Daniel Jolley  Daniel Jolley
    summary
    1

    Why is this important?

    Although we have moved beyond routinely using high tidal volumes in favour of ’protective ventilation strategies’ the specifics of what is protective and what improves outcomes is controversial. Previous trials have struggled to demonstrate post-operative respiratory benefits from protective strategies.

    What did they do?

    In this small randomised controlled trial, Généreux et al. investigated whether intraoperative PEEP (7 cmH2O) and recruitment manoeuvres (RM) q30min would reduce atelectasis post-extubation. Using ultrasound to measure intraoperative and post-operative atelectasis gives their study greater flexibility than other studies using CT scanning, generally considered the gold standard for atelectasis measurement.

    And they found...

    Among 34-85 yo women undergoing open gynae-oncology surgery >2h duration, there was no post-extubation difference in atelectasis whether receiving PEEP/RM or zero PEEP.

    Not so fast

    There was however less intraoperative atelectasis among the protective ventilation group, supporting the common use of PEEP and RM to improve oxygenation during surgery. Additionally, they specifically excluded morbidly obese women (BMI > 40 kg/m2), an increasingly common demographic at risk of ventilation challenges.

    Nonetheless this study adds to the evidence that current protective ventilation strategies do not actually reduce post-operative respiratory complications.

    Be smart

    One interesting observation was the large amount of inter-patient variability, the researchers noting:

    “...this heterogeneity highlights the need to dynamically monitor lung aeration changes and personalise our delivery of mechanical ventilation in the perioperative setting.”

    As with many perioperative interventions, the benefits may in fact lie in the personalisation of our care for each individual patient.

    Daniel Jolley  Daniel Jolley
     
    Do you have a pearl, summary or comment to save or share?
    300 characters remaining
    help        
    You can also include formatting, links, images and footnotes in your notes
    • Simple formatting can be added to notes, such as *italics*, _underline_ or **bold**.
    • Superscript can be denoted by <sup>text</sup> and subscript <sub>text</sub>.
    • Numbered or bulleted lists can be created using either numbered lines 1. 2. 3., hyphens - or asterisks *.
    • Links can be included with: [my link to pubmed](http://pubmed.com)
    • Images can be included with: ![alt text](https://bestmedicaljournal.com/study_graph.jpg "Image Title Text")
    • For footnotes use [^1](This is a footnote.) inline.
    • Or use an inline reference [^1] to refer to a longer footnote elseweher in the document [^1]: This is a long footnote..

    hide…

What will the 'Medical Journal of You' look like?

Start your free 21 day trial now.

We guarantee your privacy. Your email address will not be shared.