Autotitrating external positive end-expiratory airway pressure to abolish expiratory flow limitation during tidal breathing in patients with severe COPD: a physiological study

2020 ◽  
Vol 56 (3) ◽  
pp. 1902234 ◽  
Author(s):  
Eui-Sik Suh ◽  
Pasquale Pompilio ◽  
Swapna Mandal ◽  
Peter Hill ◽  
Georgios Kaltsakas ◽  
...  
Keyword(s):  
Respiratory Failure ◽  
Chronic Respiratory Failure ◽  
Forced Oscillation Technique ◽  
Flow Limitation ◽  
Positive End Expiratory Pressure ◽  
Tidal Breathing ◽  
Expiratory Flow Limitation ◽  
Transdiaphragmatic Pressure ◽  
Expiratory Flow ◽  
Severe Copd

BackgroundThe optimal noninvasive application of external positive end-expiratory pressure (EPAP) to abolish tidal-breathing expiratory flow limitation (EFLT) and minimise intrinsic positive end-expiratory pressure (PEEPi) is challenging in COPD patients. We investigated whether auto-titrating EPAP, using the forced oscillation technique (FOT) to detect and abolish EFLT, would minimise PEEPi, work of breathing and neural respiratory drive (NRD) in patients with severe COPD.MethodsPatients with COPD with chronic respiratory failure underwent auto-titration of EPAP using a FOT-based algorithm that detected EFLT. Once optimal EPAP was identified, manual titration was performed to assess NRD (using diaphragm and parasternal intercostal muscle electromyography, EMGdi and EMGpara, respectively), transdiaphragmatic inspiratory pressure swings (ΔPdi), transdiaphragmatic pressure–time product (PTPdi) and PEEPi, between EPAP levels 2 cmH2O below to 3 cmH2O above optimal EPAP.ResultsOf 10 patients enrolled (age 65±6 years; male 60%; body mass index 27.6±7.2 kg.m−2; forced expiratory volume in 1 s 28.4±8.3% predicted), eight had EFLT, and optimal EPAP was 9 (range 4–13) cmH2O. NRD was reduced from baseline EPAP at 1 cmH2O below optimal EPAP on EMGdi and at optimal EPAP on EMGpara. In addition, at optimal EPAP, PEEPi (0.80±1.27 cmH2O versus 1.95± 1.70 cmH2O; p<0.05) was reduced compared with baseline. PTPdi (10.3±7.8 cmH2O·s−1versus 16.8±8.8 cmH2O·s−1; p<0.05) and ΔPdi (12.4±7.8 cmH2O versus 18.2±5.1 cmH2O; p<0.05) were reduced at optimal EPAP+1 cmH2O compared with baseline.ConclusionAutotitration of EPAP, using a FOT-based algorithm to abolish EFLT, minimises transdiaphragmatic pressure swings and NRD in patients with COPD and chronic respiratory failure.

Expiratory flow limitation and intrinsic positive end-expiratory pressure in obesity

1998 ◽  
Vol 85 (4) ◽  
pp. 1236-1243 ◽  
Author(s):  
W. Pankow ◽  
T. Podszus ◽  
T. Gutheil ◽  
T. Penzel ◽  
J.-H. Peter ◽  
...  
Keyword(s):  
Supine Position ◽  
Lateral Position ◽  
Normal Weight ◽  
Upright Position ◽  
Flow Limitation ◽  
Positive End Expiratory Pressure ◽  
Expiratory Flow Limitation ◽  
Transdiaphragmatic Pressure ◽  
Expiratory Flow ◽  
The Right

Breathing at very low lung volumes might be affected by decreased expiratory airflow and air trapping. Our purpose was to detect expiratory flow limitation (EFL) and, as a consequence, intrinsic positive end-expiratory pressure (PEEPi) in grossly obese subjects (OS). Eight OS with a mean body mass index (BMI) of 44 ± 5 kg/m2 and six age-matched normal-weight control subjects (CS) were studied in different body positions. Negative expiratory pressure (NEP) was used to determine EFL. In contrast to CS, EFL was found in two of eight OS in the upright position and in seven of eight OS in the supine position. Dynamic PEEPi and mean transdiaphragmatic pressure (mean Pdi) were measured in all six CS and in six of eight OS. In OS, PEEPi increased from 0.14 ± 0.06 (SD) kPa in the upright position to 0.41 ± 0.11 kPa in the supine position ( P < 0.05) and decreased to 0.20 ± 0.08 kPa in the right lateral position ( P < 0.05, compared with supine), whereas, in CS, PEEPi was significantly smaller (<0.05 kPa) in each position. In OS, mean Pdi in each position was significantly larger compared with CS. Mean Pdi increased from 1.02 ± 0.32 kPa in the upright position to 1.26 ± 0.17 kPa in the supine position (not significant) and decreased to 1.06 ± 0.26 kPa in the right lateral position ( P < 0.05, compared with supine), whereas there were no significant changes in CS. We conclude that in OS 1) tidal breathing can be affected by EFL and PEEPi; 2) EFL and PEEPi are promoted by the supine posture; and 3) the increased diaphragmatic load in the supine position is, in part, related to PEEPi.

Lung and chest wall mechanics in patients with acute respiratory distress syndrome, expiratory flow limitation, and airway closure

2020 ◽  
Vol 128 (6) ◽  
pp. 1594-1603 ◽  
Author(s):  
Claude Guérin ◽  
Nicolas Terzi ◽  
Louis-Marie Galerneau ◽  
Mehdi Mezidi ◽  
Hodane Yonis ◽  
...  
Keyword(s):  
Mechanical Ventilation ◽  
Distress Syndrome ◽  
Flow Limitation ◽  
Airway Closure ◽  
Positive End Expiratory Pressure ◽  
Expiratory Flow Limitation ◽  
Lung Elastance ◽  
Chest Wall Mechanics ◽  
Expiratory Flow ◽  
Better Than

Expiratory flow limitation (EFL) and airway closure (AC) were observed in 32% and 52%, respectively, of 25 patients with ARDS investigated during mechanical ventilation in supine position with a positive end-expiratory pressure of 5 cmH2O. The performance of dynamic lung elastance to detect expiratory flow limitation was good and better than that to detect airway closure. The vast majority of patients with EFL also had AC; however, AC can occur in the absence of EFL.

Time Course of Expiratory Flow Limitation in COPD Patients During Acute Respiratory Failure Requiring Mechanical Ventilation

CHEST Journal ◽  
2003 ◽  
Vol 123 (5) ◽  
pp. 1625-1632 ◽  
Author(s):  
Valentina Alvisi ◽  
Anna Romanello ◽  
Michel Badet ◽  
Sandrine Gaillard ◽  
Francois Philit ◽  
...  
Keyword(s):  
Mechanical Ventilation ◽  
Respiratory Failure ◽  
Acute Respiratory Failure ◽  
Time Course ◽  
Flow Limitation ◽  
Expiratory Flow Limitation ◽  
Copd Patients ◽  
Expiratory Flow

scholarly journals Airway dynamics in COPD patients by within-breath impedance tracking: effects of continuous positive airway pressure

2017 ◽  
Vol 49 (2) ◽  
pp. 1601270 ◽  
Author(s):  
András Lorx ◽  
Dorottya Czövek ◽  
Zoltán Gingl ◽  
Gergely Makan ◽  
Bence Radics ◽  
...  
Keyword(s):  
Continuous Positive Airway Pressure ◽  
Airway Pressure ◽  
Positive Airway Pressure ◽  
Forced Oscillation Technique ◽  
Flow Limitation ◽  
Expiratory Flow Limitation ◽  
Large Variability ◽  
Normal Breathing ◽  
Copd Patients ◽  
Expiratory Flow

Tracking of the within-breath changes of respiratory mechanics using the forced oscillation technique may provide outcomes that characterise the dynamic behaviour of the airways during normal breathing.We measured respiratory resistance (Rrs) and reactance (Xrs) at 8 Hz in 55 chronic obstructive pulmonary disease (COPD) patients and 20 healthy controls, and evaluated Rrs and Xrs as functions of gas flow (V′) and volume (V) during normal breathing cycles. In 12 COPD patients, additional measurements were made at continuous positive airway pressure (CPAP) levels of 4, 8, 14 and 20 hPa.The Rrs and Xrsversus V′ and V relationships displayed a variety of loop patterns, allowing characterisation of physiological and pathological processes. The main outcomes emerging from the within-breath analysis were the Xrsversus V loop area (AXV) quantifying expiratory flow limitation, and the tidal change in Xrs during inspiration (ΔXI) reflecting alteration in lung inhomogeneity in COPD. With increasing CPAP, AXV and ΔXI approached the normal ranges, although with a large variability between individuals, whereas mean Rrs remained unchanged.Within-breath tracking of Rrs and Xrs allows an improved assessment of expiratory flow limitation and functional inhomogeneity in COPD; thereby it may help identify the physiological phenotypes of COPD and determine the optimal level of respiratory support.

scholarly journals Detection of expiratory flow limitation in COPD using the forced oscillation technique

2004 ◽  
Vol 23 (2) ◽  
pp. 232-240 ◽  
Author(s):  
R.L. Dellacà ◽  
P. Santus ◽  
A. Aliverti ◽  
N. Stevenson ◽  
S. Centanni ◽  
...  
Keyword(s):  
Forced Oscillation ◽  
Forced Oscillation Technique ◽  
Flow Limitation ◽  
Expiratory Flow Limitation ◽  
Expiratory Flow
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