Correlation between continuous Positive end-expiratory pressure (PEEP) values and occurrence of Pneumothorax and Pneumomediastinum in SARS-CoV2 patients during non-invasive ventilation with Helmet

  1. Antonio Gidaro
  2. Federica Samartin
  3. Anna M. Brambilla
  4. Chiara Cogliati
  5. Stella Ingrassia
  6. Francesco Banfi
  7. Viola Cupiraggi
  8. Cecilia Bonino
  9. Marco Schiuma
  10. Andrea Giacomelli
  11. Stefano Rusconi
  12. Jaqueline Currà
  13. Antonio Luca Brucato
  14. Emanuele Salvi

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Abstract

Background

Acute Hypoxemic Respiratory Failure is a common complication of SARS-CoV2 related pneumonia, for which non-invasive ventilation (NIV) with Helmet Continuous Positive Airway Pressure (CPAP) is widely used. The frequency of pneumothorax in SARS-CoV2 was reported in 0.95% of hospitalized patients in 6% of mechanically ventilated patients, and in 1% of a post-mortem case series.

Objectives

Aim of our retrospective study was to investigate the incidence of pneumothorax and pneumomediastinum (PNX/PNM) in SARS-CoV2 pneumonia patients treated with Helmet CPAP. Moreover, we examined the correlation between PNX/PNM and Positive end-expiratory pressure (PEEP) values.

Methods

We collected data from patients admitted to “Luigi Sacco” University Hospital of Milan from 2 February to 5 May 2020 with SARS-CoV2 pneumonia requiring CPAP. Patients, who need NIV with bi-level pressure or endotracheal intubation (ETI) for any reason except those who needed ETI after PNX/PNM, were excluded. Population was divided in two groups according to PEEP level used (≤10 cmH2O and >10 cmH20).

Results

154 patients were enrolled. In the overall population, 42 patients (27%) were treated with High-PEEP (>10 cmH2O), and 112 with Low-PEEP (≤10 cmH2O). During hospitalization 3 PNX and 2 PNM occurred (3.2%). Out of these five patients, 2 needed invasive ventilation after PNX and died. All the PNX/PNM occurred in the High-PEEP group (5/37 vs 0/112, p<0,001).

Conclusion

The incidence of PNX appears to be lower in SARS-CoV2 than SARS and MERS. Considering the association of PNX/PNM with high PEEP we suggest using the lower PEEP as possible to prevent these complications.

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  1. Version published to 10.1101/2020.08.31.20185348v2 on medRxiv
  2. ScreenIT

    SciScore for 10.1101/2020.08.31.20185348: (What is this?)

    Please note, not all rigor criteria are appropriate for all manuscripts.

    Table 1: Rigor

    Institutional Review Board StatementIACUC: The study (“REGISTRO DELLE INFEZIONI SOSPETTE E ACCERTATE COVID-19/Studio Sacco COVID-19)” was approved by the local ethical committee with the registration number 2020/16088.
    Randomizationnot detected.
    Blindingnot detected.
    Power Analysisnot detected.
    Sex as a biological variablenot detected.

    Table 2: Resources

    Software and Algorithms
    SentencesResources
    The statistical analysis of data was done by using Excel (Office program 2010) and SPSS (statistical package for social science-SPSS, Inc., Chicago, IL version 20).
    SPSS
    suggested: (SPSS, RRID:SCR_002865)

    Results from OddPub: We did not detect open data. We also did not detect open code. Researchers are encouraged to share open data when possible (see Nature blog).

    Results from LimitationRecognizer: We detected the following sentences addressing limitations in the study:
    Our study has several limitations. First of all, the number of events is low and for this reason our results, and in particular the association of PNX/PNM with higher PEEP, has to be confirmed in multicentric studies with a wider population. Moreover, our study is retrospective: PEEP values were decided by the clinician for each patient and in particular higher PEEP values have been set in the first weeks and subsequently lowered on the basis of clinical experience and data emerging from literature. In the end, we did not collected data about pneumoperitoneum or subcutaneous emphysema which can be classified as possible barotrauma even if rare.

    Results from TrialIdentifier: No clinical trial numbers were referenced.

    Results from Barzooka: We did not find any issues relating to the usage of bar graphs.

    Results from JetFighter: We did not find any issues relating to colormaps.

    Results from rtransparent:
    • Thank you for including a conflict of interest statement. Authors are encouraged to include this statement when submitting to a journal.
    • Thank you for including a funding statement. Authors are encouraged to include this statement when submitting to a journal.
    • No protocol registration statement was detected.

    About SciScore

    SciScore is an automated tool that is designed to assist expert reviewers by finding and presenting formulaic information scattered throughout a paper in a standard, easy to digest format. SciScore checks for the presence and correctness of RRIDs (research resource identifiers), and for rigor criteria such as sex and investigator blinding. For details on the theoretical underpinning of rigor criteria and the tools shown here, including references cited, please follow this link.

  3. Version published to 10.1101/2020.08.31.20185348v1 on medRxiv