X-ray Identifies More Air Pressure Lung Injuries in COVID-19 Patients

Patients with COVID-19 pneumonia who must be placed on a ventilator are more likely than other patients to experience an injury from increased air pressure in their lungs, placing them at a higher risk of death, new research has found.

In a study published July 2 in Radiology, investigators from New York University (NYU) Langone Health discussed their observation that more patients with COVID-19 infection on ventilators developed barotrauma – an injury associated with elevated air pressure in the lungs – than did other patients who required intubation. Being aware of this risk can be vital for optimizing patient care, the researchers said.

Pneumomediastinum and Bilateral Pneumothoraces, Separated by 7 days. 20-year-old woman intubated 5 days after admission. (a) Frontal chest radiograph depicts moderate pneumomediastinum (black arrows) and subcutaneous emphysema. Courtesy: Radiology

“High barotrauma rates in patients with COVID-19 infection on [invasive mechanical ventilation] is associated with longer hospital stay and is a risk factor for higher mortality,” said the team led by Georgeann McGuinness, M.D., senior vice chair of the NYU Langone Health radiology department. “Barotrauma risk is particularly important to recognize as these critically ill patients may be managed by staff less familiar with the management of ventilator settings.”

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To determine the rate of barotrauma in COVID-19 patients, the team evaluated chest X-rays from 601 patients over age 18 who were positive for the virus and were also put on a ventilator. Of that group, 89 patients – 15 percent – developed at least one barotrauma event. All total, this group experienced 145 barotrauma episodes for an overall barotrauma rate of 24 percent. Specifically, the team identified:

• 31 patients with left pneumothorax
• 35 patients with right pneumothorax
• 11 patients with bilateral pneumothoraces
• 54 patients with either unilateral or bilateral pneumothorax
• 59 patients with pneumomediastinum (the most common barotrauma event)
• 14 patients with pneumopericardium

They compared these results to the incidence of barotrauma in a group of 196 intubated patients who were negative for the virus. In that group, investigators identified only one event. The team also compared these findings to 285 intubated patients with acute respiratory distress syndrome (ARDS) from 2016 to 2020. During that time, 28 patients had 31 barotrauma events – a rate of 11 percent.

Pneumomediastinum and Bilateral Pneumothoraces, Separated by 7 days. 20-year-old woman intubated 5 days after admission. Four days later, she developed large bilateral pneumothoraces (white arrows), and extensive subcutaneous emphysema. Courtesy: Radiology

These findings fall in line with previous research that examined barotrauma rates during the SARS and MERS outbreaks. According to that data, between 12 percent and 34 percent of SARS patients developed barotrauma, and 30 percent of intubated MERS patients in the intensive care unit experienced pneumothorax. These rates, the team said, beg the question of whether coronavirus infections present a unique barotrauma risk.

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Overall, the team determined that the COVID-19 patients who develop barotrauma were younger than intubated ARDS or COVID-19-negative patients (63 years versus 68 years), suggesting that younger age in these patients after ventilation is an independent barotrauma risk factor. Additionally, a multivariate analysis revealed that alongside barotrauma, mortality in COVID-19-positive patients in this study was associated with greater age, shorter hospital length of stay, and Hispanic ethnicity.

Ultimately, the team said, they hope these findings can be used clinically to improve patient outcomes.

“Our observed high rate of barotrauma in patients with COVID-19 infection on [invasive mechanical ventilation] may support emerging theories of lung damage in SARS-CoV-2 infection,” they said.