scholarly journals A new noninvasive method for measurement of dynamic lung compliance from fluctuations on photoplethysmography in respiration.

2020 ◽  
Author(s):  
Haruna Yamazaki ◽  
Keisaku Fujimoto
Keyword(s):  
Interstitial Lung Disease ◽  
Convenient Method ◽  
Healthy Adult ◽  
Esophageal Pressure ◽  
Lung Compliance ◽  
Pressure Probe ◽  
Noninvasive Method ◽  
Esophageal Balloon ◽  
Dynamic Lung Compliance ◽  
Adult Volunteers

Lung compliance is important in interstitial lung disease (ILD) as a marker of lung sclerosis. However, the measurement requires placement of an esophageal pressure probe, and is therefore not done routinely in clinic. This study was performed to develop and verify a new noninvasive method for estimation of dynamic lung compliance (Cdyn) using a photoplethysmograph (PPG), and to examine its usefulness. A system for measuring Cdyn in combination with changes in estimated pleural pressure (Ppl) from the fluctuations on PPG with respiration and lung volume measured simultaneously by spirometry was developed, and verified to show correspondence with the estimated Ppl and the esophageal pressure (Pes) (healthy adult volunteers (HS); n = 3), and estimated Cdyn and Cdyn measured using an esophageal balloon (HS; n = 28, COPD; n = 14, ILD; n = 10). Further, the estimated Cdyn was compared among HS (n = 33), COPD (n = 31), and ILD (n = 30). Both the estimated Ppl and Cdyn were significantly correlated with the Pes (r = 0.89) and measured Cdyn (r = 0.63), respectively. The estimated Cdyn in ILD showed significant lower values than those in HS and COPD. The estimated Cdyn was significantly related to %VC (r = 0.56, P < 0.01) and %DLCO (r = 0.52, P < 0.01) in patients with ILD. These findings suggested that the newly developed noninvasive and convenient method for estimation of Cdyn using a combination of PPG and spirometry may be useful for the assessment of lung sclerosis in ILD.

Lung mechanics in sitting and horizontal postures studied by body plethysmographic methods

1963 ◽  
Vol 204 (1) ◽  
pp. 85-91 ◽  
Author(s):  
Håkan Linderholm
Keyword(s):  
Mechanical Properties ◽  
Normal Subjects ◽  
Esophageal Pressure ◽  
Lung Compliance ◽  
Lung Mechanics ◽  
Lung Volumes ◽  
Dynamic Lung Compliance ◽  
Pressure Changes ◽  
Airway Conductance ◽  
Better Than

Mechanical properties of the lungs were examined in normal subjects in the sitting and supine body postures using body plethysmographic and conventional methods. At comparable lung volumes airway conductance or resistance (measured independently of esophageal pressure) was quite uninfluenced, and lung conductance or resistance (determined during high-frequency breathing, when esophageal pressure and intrapleural pressure variations are known to agree better than during ordinary breathing) was almost uninfluenced by changes in body posture. A "static" lung compliance estimated from plethysmographically measured lung volumes and the corresponding esophageal pressures was less influenced by posture than the conventionally measured "dynamic" lung compliance. Previously reported differences between lung compliance or resistance in the sitting and supine postures seem to be explained by differences in lung volumes at the measurements and probably also by the variation with posture of differences between intrapleural and esophageal pressure changes during ordinary breathing. Changing from upright to horizontal posture therefore does not seem to alter significantly the true mechanical properties of the lungs.

Esophageal Pressure Measurements in Patients With Acute Respiratory Distress Syndrome

2016 ◽  
Vol 36 (5) ◽  
pp. 27-35
Author(s):  
Grace Hofmann ◽  
Lutana Haan ◽  
Jeff Anderson
Keyword(s):  
Acute Respiratory Distress Syndrome ◽  
Respiratory Distress Syndrome ◽  
Respiratory Distress ◽  
Distress Syndrome ◽  
Esophageal Pressure ◽  
Lung Compliance ◽  
Patient Specific ◽  
Esophageal Balloon ◽  
Wall Compliance ◽  
Tailored Approach

Esophageal balloons are used in the respiratory monitoring of critical care patients. After the esophageal pressure is measured, the corresponding pleural pressure in the thorax can be projected, enabling lung-thorax compliance to be partitioned into chest-wall compliance and lung compliance. The esophageal balloon allows determination of transpulmonary pressures and a correspondingly individually tailored approach to respiratory care, such as patient-specific titration of positive end-expiratory pressure for patients with extrapulmonary acute respiratory distress syndrome. Esophageal balloon monitoring provides critical information for selecting ventilation strategies to use in patients with acute respiratory distress syndrome.

A re-evaluation of effects of acute central congestion on pulmonary compliance in normal subjects

1960 ◽  
Vol 15 (5) ◽  
pp. 875-877 ◽  
Author(s):  
Stuart Bondurant ◽  
Jere Mead ◽  
C. D. Cook
Keyword(s):  
Pressure Change ◽  
Normal Subjects ◽  
Esophageal Pressure ◽  
Lung Compliance ◽  
Abdominal Compression ◽  
Pulmonary Compliance ◽  
Vascular Congestion ◽  
Esophageal Balloon ◽  
Artifactual Changes ◽  
Valid Index

In a re-examination of the effects on lung compliance of acute central vascular engorgement produced in normal subjects by inflation of a ‘G suit’ it was found that the reduction in complicance, previously reported, during suit inflation was in part due to artifactual changes in esophageal pressure. When the esophageal balloon used for pressure recording was positioned higher on the esophagus than in the previous study, and when decreases in mid-position, which usually accompany the abdominal compression associated with suit inflation, were prevented, the complicance reductions in a small group of subjects were approximately one-half as great as those obtained with the balloon low in the esophagus and with the mid-position uncontrolled. Extrinsic pressures from distended mediastinal structures, greater in the distal esophagus, and greater at low lung volumes are thought to be responsible. Additional observations are presented which support this possibility. It is concluded that respiratory esophageal pressure change may not be a valid index of lung surface pressure change in the presence of central vascular congestion. Those measurements of pulmonary compliance during clinical and experimental central vascular engorgement which have used esophageal pressure must be accepted with this reservation. Submitted on March 18, 1960

Interleukin 10-induced thrombocytopenia in normal healthy adult volunteers: evidence for decreased platelet production

2000 ◽  
Vol 111 (1) ◽  
pp. 104-111 ◽  
Author(s):  
Jeffrey A. Sosman ◽  
Amit Verma ◽  
Steven Moss ◽  
Patricia Sorokin ◽  
Michael Blend ◽  
...  
Keyword(s):  
Healthy Adult ◽  
Interleukin 10 ◽  
Platelet Production ◽  
Adult Volunteers
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