Particle flow rate from the airways as fingerprint diagnostics in mechanical ventilation in the intensive care unit: a randomised controlled study

Filip Hallgren; Martin Stenlo; Anna Niroomand; Ellen Broberg; Snejana Hyllén; Malin Malmsjö; Sandra Lindstedt

doi:10.1183/23120541.00961-2020

Particle flow rate from the airways as fingerprint diagnostics in mechanical ventilation in the intensive care unit: a randomised controlled study

ERJ Open Res. 2021 Jul 26;7(3):00961-2020. doi: 10.1183/23120541.00961-2020. eCollection 2021 Jul.

Authors

Filip Hallgren¹, Martin Stenlo^{2

3

4

5}, Anna Niroomand^{3

4

5

6}, Ellen Broberg^{2

3

4

5}, Snejana Hyllén^{2

3

4

5}, Malin Malmsjö⁴, Sandra Lindstedt^{1

3

4

5}

Affiliations

¹ Dept of Cardiothoracic Surgery and Transplantation, Skåne University Hospital, Lund University, Lund, Sweden.
² Cardiothoracic Anaesthesia and Intensive Care, Skåne University Hospital, Lund University, Lund, Sweden.
³ Wallenberg Center for Molecular Medicine, Lund University, Lund, Sweden.
⁴ Dept of Clinical Sciences, Lund University, Lund, Sweden.
⁵ Lund Stem Cell Center, Lund University, Lund, Sweden.
⁶ Rutgers Robert Wood Johnson Medical School, New Brunswick, NJ, USA.

Abstract

Introduction: Mechanical ventilation can be monitored by analysing particles in exhaled air as measured by particle flow rate (PFR). This could be a potential method of detecting ventilator-induced lung injury (VILI) before changes in conventional parameters can be detected. The aim of this study was to investigate PFR during different ventilation modes in patients without lung pathology.

Method: A prospective study was conducted on patients on mechanical ventilation in the cardiothoracic intensive care unit (ICU). A PExA 2.0 device was connected to the expiratory limb on the ventilator for continuous measurement of PFR in 30 patients randomised to either volume-controlled ventilation (VCV) or pressure-controlled ventilation (PCV) for 30 min including a recruitment manoeuvre. PFR measurements were continued as the patients were transitioned to pressure-regulated volume control (PRVC) and then pressure support ventilation (PSV) until extubation.

Results: PRVC resulted in significantly lower PFR, while those on PSV had the highest PFR. The distribution of particles differed significantly between the different ventilation modes.

Conclusions: Measuring PFR is safe after cardiac surgery in the ICU and may constitute a novel method of continuously monitoring the small airways in real time. A low PFR during mechanical ventilation may correlate to a gentle ventilation strategy. PFR increases as the patient transitions from controlled mechanical ventilation to autonomous breathing, which most likely occurs as recruitment by the diaphragm opens up more distal airways. Different ventilation modes resulted in unique particle patterns and could be used as a fingerprint for the different ventilation modes.