Barotrauma in covid - Causes and consequences.

Dear Editor,

In a retrospective case series of Covid-19 patients, Edwards et al. define barotrauma as the presence of ‘extrapulmonary air’ on chest X-ray (CXR) [1]. Clearly, one would include the occurrence of pneumo-pericardium within that category [2]. We note its presence on one of their images although it was not described as such. In using CXR to detect barotrauma, it of course has lower sensitivity and specificity than computerized tomographic (CT) imaging. Thus their dataset, though large, may underestimate the true risk of barotrauma. While it may not be always possible to routinely use CT imaging, perhaps ultrasound might have detected more, or better characterized known, cases [3].

Furthermore, although the authors reported following Acute Respiratory Distress Syndrome Network protocols in treating patients, the data shown in table 3 is at times inconsistent with that approach. In patients with chronic obstructive pulmonary disease and asthma, additional information on plateau and driving pressure, or airway resistance, better reflects the risk of barotrauma than peak or mean airway pressure (Ppeak, Pmean) [4]. Notably, some patients who developed pneumothorax had received lower positive end-expiratory pressure (PEEP), Ppeak, and Pmean. Therefore, it is crucial to know whether Peak, Pmean, and PEEP levels differed between those who did, and those who did not, suffer barotrauma [4,5].

Finally, and importantly, we wonder if barotrauma was associated with more severe COVID-19 infection (as measured by C-reactive protein, lymphopenia, D-dimer, or viral load, for example) at presentation, or in terms of their overall clinical course. We would also inquire whether their sedation, muscle relaxant, and prone positioning requirements during mechanical ventilation differed from other patients, as crude markers of disease severity.

We thank the authors’ for this useful study, and would greatly welcome clarification on the above issues.

Financial support

No funding other than personal was used in conducting the audit as well as writing the manuscript. We declare that we have no financial and/or personal relationships with other people or organizations that could inappropriately influence (bias) our work.

Ethical approval

Not applicable.

Consent

Not necessary as this is mere correspondence to published article in your journal.

Author contribution

Dr. Pradipta Bhakta: Was involved analysis of the article, writing and editing the letter.

Dr. Habib Md Reazaul Karim: Was involved analysis of the article, writing and editing the letter.

Dr. Mohanchandra Mandal: Was involved analysis of the article, writing and editing the letter.

Dr. Brian O'Brien: Was involved analysis of the article, writing and editing the letter.

Dr. Antonio M. Esquinas: Was involved analysis of the article, writing and editing the letter.

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Guarantor

Dr. Pradipta Bhakta, Consultant, Department of Anaesthesiology and Intensive Care, University Hospital Kerry, Tralee, Co: Kerry, Ireland. Email: bhaktadr@hotmail.com.

Declaration of competing interest

The authors report no conflicts of interest.