Background: This article discusses the challenges and controversies in the management of the unique respiratory failure caused by COVID-19 pneumonia. Many uncertainties prevail in the treatment of this disease. There remains no clear consensus on the timing of intubation and trial of noninvasive therapies prior to intubation. We will discuss here the surrogate markers of deteriorating respiratory function and pulmonary infiltrates that could be utilized to prevent delayed intubation. We also discuss the proposal by Gattinoni et al. in employing a rather high tidal volume and low PEEP technique.
Main study: We review the importance of consideration of work of breathing, P-SILI and ultrasound lung in decision-making process. We discuss the ill effects of high tidal volumes in inducing lung strain with larger dynamic deformations and the benefit of high PEEP in homogenizing the strain distribution. The article proposes that the ground glass opacities seen in COVID-19 pneumonia could pose as ‘stress raisers’? If so, there may be importance to high PEEP in the L phenotype despite lower recruitability. The article also questions the appropriate tidal volume to be applied to this ‘larger baby lung’ in L phenotype.
Conclusion: Measures to avoid delays in recognition of need for intubation and escalation of care are key to avoid further damage from P-SILI. Clinical assessment of work of breathing and intubating at the earliest signs of respiratory distress may prevent P-SILI. While optimum ventilation strategy for ‘L’ phenotype remains a matter of ongoing discussion, risks of inducing lung injury with the approach employing the high tidal volume and low PEEP technique need to considered. The COVID-19 respiratory failure poses more questions and challenges our traditional protocols of ARDS management. Perhaps, forgoing protocols and a more individualized and prescribed mechanical ventilation setting may not only show more respect and appreciation for its varied presentations but may also translate into better patient outcomes.
Simran Kaur Matta