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Correspondence  |   May 2020
Intubation and Ventilation amid COVID-19: Reply
Author Notes
  • Shanghai Fourth People’s Hospital, Tongji University School of Medicine, Shanghai, China (L.X.). mzkxlz@126.com
  • (Accepted for publication April 23, 2020.)
    (Accepted for publication April 23, 2020.)×
  • Competing Interests: The authors declare no competing interests.
    Competing Interests: The authors declare no competing interests.×
Article Information
Correspondence
Correspondence   |   May 2020
Intubation and Ventilation amid COVID-19: Reply
Anesthesiology Newly Published on May 8, 2020. doi:https://doi.org/10.1097/ALN.0000000000003375
Anesthesiology Newly Published on May 8, 2020. doi:https://doi.org/10.1097/ALN.0000000000003375
In Reply:
We thank Dr. Rigatelli et al.1  for their letter discussing the role of lung ultrasonography in mechanically ventilated coronavirus disease 2019 (COVID-19) patients. They elegantly presented the advantages associated with the use of bedside lung ultrasonography amid the current pandemic. Our paper published in Anesthesiology did not specifically discuss the experience of using lung ultrasonography in critically ill COVID-19 patients.2  However, we had a letter published in Intensive Care Medicine that had specifically summarized our early experience of using lung ultrasonography in COVID-19 patients in Wuhan, China.3 
The characteristic lung ultrasonographic findings in COVID-19 patients are (1) pleural line thickening, irregularity, and fusion; (2) focal, multifocal, or confluent B lines; (3) multifocal small, nontranslobar, and translobar (with occasional mobile air bronchograms) consolidations; and (4) A lines during the recovery phase.3  The potential usage of lung ultrasonography in critically ill COVID-19 patients is as follows.
First, although the cause of respiratory failure in COVID-19 patients is primarily related to acute lung injury, other abnormalities involving the airway, chest cavity, chest wall compliance, pulmonary vasculature, and the heart cannot be ignored. Differential diagnosis of the cause of respiratory failure is essential throughout the treatment process, especially when lung injury itself cannot fully explain the whole picture. Lung ultrasonography can help to quickly screen for the potential causes of respiratory failure in COVID-19 patients.
Second, it is the current consensus that the timely application of appropriate gas exchange support is essential in COVID-19 patients complicated with acute hypoxemic respiratory failure. However, what is challenging and sometimes controversial is when to convert noninvasive gas exchange support (such as regular oxygen therapy, high-flow nasal cannula, and noninvasive ventilation) to intubation and invasive mechanical ventilation. Lung ultrasonography assists the decision of which method of gas exchange support to choose in hypoxemic COVID-19 patients. It dynamically monitors the disease progression and evaluates the effectiveness of the ongoing therapy based on the increase and decrease of B lines, B line zones, and consolidation area and volume.
Third, in mechanically ventilated COVID-19 patients, lung ultrasonography can comprehensively assess the potential of lung recruitment based on pulmonary lesions’ uniformity and severity and the presence of dynamic air bronchograms and tidal recruitment. The potential is reduced if lung ultrasonography shows multiple sites of large-area consolidation or B line fusion. Lung ultrasonography also facilitates lung recruitment, based on qualitative or semiquantitative lung scores, to understand the condition, duration, and results of recruitment, avoid barotrauma, and adverse hemodynamic effect, and facilitate the titration of positive end-expiratory pressure.4 
Last, lung ultrasonography facilitates the determination of the duration and frequency of prone position ventilation.5  It assesses the effectiveness of lung recruitment of the gravity-dependent areas. The aeration of the inferior anterior lungs may representatively predict the effectiveness of ventilation-perfusion matching and the potential of oxygenation improvement. The ultrasonographic semiquantitative scores have also been used to predict the effectiveness of prone position ventilation.
Overall, lung ultrasonography has the potential and unique advantages in the diagnosis, treatment, and prognosis of COVID-19 patients who require gas exchange support. Moving forward, we need well-designed clinical studies to validate the use of lung ultrasonography in facilitating decision-making and improving outcomes in mechanically ventilated COVID-19 patients.
Competing Interests
The authors declare no competing interests.
References
Rigatelli, G, Zuin, M, Rigatelli, A, Zuliani, G, Roncon, L Intubation and ventilation amid COVID-19: Comment Anesthesiology 2020; XXX:XXX
Meng, L, Qiu, H, Wan, L, Ai, Y, Xue, Z, Guo, Q, Deshpande, R, Zhang, L, Meng, J, Tong, C, Liu, H, Xiong, LIntubation and ventilation amid the COVID-19 outbreak: Wuhan’s experience Anesthesiology 2020.doi: 10.1097/ALN.0000000000003296. [Epub ahead of print]
Peng, Q, Wang, X, Zhang, LGroup CCCUS Group CCCUS, Findings of lung ultrasonography of novel corona virus pneumonia during the 2019–2020 epidemic Intensive Care Med 2020.doi: 10.1007/s00134-020-05996-6. [Epub ahead of print]
Bouhemad, B, Brisson, H, Le-Guen, M, Arbelot, C, Lu, Q, Rouby, JJ Bedside ultrasound assessment of positive end-expiratory pressure-induced lung recruitment. Am J Respir Crit Care Med 2011; 183:341–7 [Article] [PubMed]
Wang, XT, Ding, X, Zhang, HM, Chen, H, Su, LX, Liu, DW Chinese Critical Ultrasound Study Group (CCUSG) Chinese Critical Ultrasound Study Group (CCUSG), Lung ultrasound can be used to predict the potential of prone positioning and assess prognosis in patients with acute respiratory distress syndrome. Crit Care 2016; 20:385 [Article] [PubMed]