Monitoring lung injury with particle flow rate in LPS‐ and COVID‐19‐induced ARDS

Abstract

In severe acute respiratory distress syndrome (ARDS), extracorporeal membrane oxygenation (ECMO) is a life‐prolonging treatment, especially among COVID‐19 patients. Evaluation of lung injury progression is challenging with current techniques. Diagnostic imaging or invasive diagnostics are risky given the difficulties of intra‐hospital transportation, contraindication of biopsies, and the potential for the spread of infections, such as in COVID‐19 patients. We have recently shown that particle flow rate (PFR) from exhaled breath could be a noninvasive, early detection method for ARDS during mechanical ventilation. We hypothesized that PFR could also measure the progress of lung injury during ECMO treatment. Lipopolysaccharide (LPS) was thus used to induce ARDS in pigs under mechanical ventilation. Eight were connected to ECMO, whereas seven animals were not. In addition, six animals received sham treatment with saline. Four human patients with ECMO and ARDS were also monitored. In the pigs, as lung injury ensued, the PFR dramatically increased and a particular spike followed the establishment of ECMO in the LPS‐treated animals. PFR remained elevated in all animals with no signs of lung recovery. In the human patients, in the two that recovered, PFR decreased. In the two whose lung function deteriorated while on ECMO, there was increased PFR with no sign of recovery in lung function. The present results indicate that real‐time monitoring of PFR may be a new, complementary approach in the clinic for measurement of the extent of lung injury and recovery over time in ECMO patients with ARDS.

New insight: particle flow rate from the airways as an indicator of cardiac failure in the intensive care unit

“…To date, both exhaled particles and other volatile compounds have been explored as a diagnostic tool for asthma, 20 chronic obstructive pulmonary disease, 21 sarcoidosis, 22 and pulmonary fibrosis 23 . Our previous studies have also shown that an increased PRF was associated with pathological lung conditions, such as ARDS, 12 including COVID‐19‐induced ARDS, 13 and primary graft dysfunction after lung transplant 14 . The current study showed the impact of the cardiac failure on particles in exhaled air in the absence of respiratory pathologies during MV.…”

“…11 We have shown previously that PFR increases in the early stages of acute respiratory disorder syndrome (ARDS) in a porcine ARDS model 12 as well as in extra-corporeal membrane oxygenation models. 13 In preclinical settings using ex vivo lung perfusion, we have shown that cardiac output is correlated to PFR. 7 However, there are no data regarding PFR in patients with cardiac failure nor on which size distribution of particles can be detected in this patient population.…”

“… 11 We have shown previously that PFR increases in the early stages of acute respiratory disorder syndrome (ARDS) in a porcine ARDS model 12 as well as in extra‐corporeal membrane oxygenation models. 13 …”

“…Valuable diagnostic data as, for example, information on injuries within the respiratory system, may be provided with this method 11 . We have shown previously that PFR increases in the early stages of acute respiratory disorder syndrome (ARDS) in a porcine ARDS model 12 as well as in extra‐corporeal membrane oxygenation models 13 …”

Exhaled phospholipid transfer protein and hepatocyte growth factor receptor in lung adenocarcinoma

“…We aimed to evaluate proteins in EBP as well as analyzing PFR before and 1 month after surgery and comparing the results between LUAD patients and control patients, thereby evaluating the potential to use EBP and PFR as diagnostic tools. Analyzing EBP and PFR have previously been proven useful in diagnosing and evaluating other pulmonary diseases such as asthma, acute respiratory distress syndrome (ARDS) and primary graft dysfunction (PGD) in lung transplant recipients and in patients with COVID-19 by us and other research groups [10,14,15,[17][18][19].…”