Regional Lung Volume Research Articles

Effect of chest strapping on regional lung function.

We studied lung mechanics and regional lung function in five young men during restrictive chest strapping. The effects on lung mechanics were similar to those noted by others in that lung elastic recoil increased as did maximum expiratory flow at low lung volumes. Chest strapping reduced the maximum expiratory flow observed at a given elastic recoil pressure. Breathing helium increased maximum expiratory flow less when subjects were strapped than when they were not. These findings indicated that strapping decreased the caliber of airways upstream from the equal pressure point. Regional lung volumes from apex to base were measured with xenon 133 while subjects were seated. The distribution of regional volumes was measured at RV, and at volumes equal to strapped FRC and strapped TLC; no change due to chest strapping was observed. Similarly, the regional distribution of 133Xe boluses inhaled at RV and strapped TLC was unaffected by chest strapping. Closing capacity decreased with chest strapping. We concluded that airway closure decreased during chest strapping and that airway closure was not the cause of the observed increase in elastic recoil of the lung. The combination of decreased slope of the static pressure-volume curve and unchanged regional volumes suggested that strapping increased the apex-to-base pleural pressure gradient.

Respiratory function in esophageal hiatus hernia. II. Regional lung function.

64 subjects with hiatus hernia (34 sliding, 22 mixed, and 8 of paraesophageal variety) were divided into 3 groups according to the transverse diameter of the thoracic loculus and examined by 133Xe-radio-spirometry in the supine position. 48 subjects (22 sliding, 18 mixed, and 8 or paraesophageal variety) showed a significant reduction in the regional ventilation, perfusion or lung volume. Significant correlations were found between the diameter of the thoracic loculus and the reduction in these vairables of the affected lung.

Aspects of lung expansion in relation to pulmonary physiotherapy.

Different procedures used in pulmonary physiotherapy that may affect lung expansion are reviewed. Distribution of regional lung volumes is dependent on body position and total lung volume. By increasing functional residual capacity, more airways may open and thus airway closure may be avoided. Ventilation distribution is flow dependent, which must be evaluated further in assessing different breathing patterns. Different breathing patterns, such as diaphragmatic and basal-costal breathing, involve changes in shape of the chest wall; however, no systematic effects on ventilation distribution have been demonstrated, although according to theoretic analyses and animal experiments the local distending pressures may be dependent on local shape changes. Instructions on such breathing types may therefore be given to achieve a “relaxed” breathing pattern or to maintain rib cage and diaphragm mobility, but not to alter ventilation distribution.

Regional lung volumes during water immersion to the xiphoid in seated man.

Regional lung volumes during water immersion to the xiphoid in seated man.

Regional lung volumes with positive pressure inflation in erect humans

Four seated subjects attained a preselected lung volume (V O) in two ways: voluntarily, and by relaxing against a positive airway pressure of 14–16 cm H 2O; V O were 1.0–1.5 L below total lung capacity. Using Xe we measured the regional distribution of lung volumes at V O under both conditions. The apex to base differences in regional expansion and, by implication, regional pleural pressure differences were the same in both conditions. All regional volumes were slightly less during positive pressure inflation, implying an increase in regional TLC, presumably due to a shift of blood volume out of the thorax.

Regional lung function in scoliosis.

Radioactive xenon-133 was used to study the pattern of regional lung function in 35 scoliotic patients and 10 normal subjects in the sitting posture. The scoliotic curves were classified into three anatomical sites: high, if the apical vertebra was located between Th1 and Th5; mid, between Th6 and Th10; and low, between Th11 and L4; only the primary curve was considered and in 70% of the patients this measured more than 60°. The mean pattern of perfusion in patients with low and mid curves was not significantly different from that of the normals, nor was there any significant difference between the convex and concave lungs in these two groups. Patients with high curves showed three distinct patterns: [List: see text] The mean pattern of ventilation in the three groups of scoliotic patients was not significantly different from that of the normals although there was wide individual variation. The only patients to show a significantly abnormal ventilation/perfusion ratio were the high group. Regional lung volumes calculated from the equilibration scan indicated that in a majority of scoliotics the lung on the convex side of the curvature was larger than that on the concave side. Our results suggest that both the anatomical site and the angle of the scoliotic curvature have an effect on regional lung function but that this effect falls equally on the convex and concave lungs.

Topography of pleural surface pressure above resting volume in relaxed animals.

ArticleTopography of pleural surface pressure above resting volume in relaxed animals.E Agostoni, E D'Angelo, and M V BonanniE Agostoni, E D'Angelo, and M V BonanniPublished Online:01 Sep 1970https://doi.org/10.1152/jappl.1970.29.3.297MoreSectionsPDF (2 MB)Download PDF ToolsExport citationAdd to favoritesGet permissionsTrack citations ShareShare onFacebookTwitterLinkedInWeChat Previous Back to Top Next Download PDF FiguresReferencesRelatedInformationCited BySequential lateral positioning as a new lung recruitment maneuver: an exploratory study in early mechanically ventilated Covid-19 ARDS patients12 February 2022 | Annals of Intensive Care, Vol. 12, No. 1Positive End-Expiratory Pressure, Pleural Pressure, and Regional Compliance during Pronation. An Experimental StudyAmerican Journal of Respiratory and Critical Care Medicine, Vol. 203, No. 10Mechanical Ventilation6 May 2014Two Steps Forward in Bedside Monitoring of Lung Mechanics: Transpulmonary Pressure and Lung VolumeComputed tomography evaluation of lung collapse and recruitment manoeuvres during anaesthesiaAcute Lung Injury: Effects of Prone Positioning on Cephalocaudal Distribution of Lung Inflation—CT Assessment in DogsRadiology, Vol. 234, No. 1Spatial distribution of ventilation and perfusion in anesthetized dogs in lateral posturesHung Chang, Stephen J. Lai-Fook, Karen B. Domino, Carmel Schimmel, Jack Hildebrandt, H. Thomas Robertson, Robb W. Glenny, and Michael P. Hlastala1 February 2002 | Journal of Applied Physiology, Vol. 92, No. 2Recruitment and Derecruitment During Acute Respiratory FailureAmerican Journal of Respiratory and Critical Care Medicine, Vol. 164, No. 1Influence of abdomen on respiratory mechanics in supine rabbitsRespiration Physiology, Vol. 115, No. 3A Computed Tomography Scan Assessment of Regional Lung Volume in Acute Lung InjuryAmerican Journal of Respiratory and Critical Care Medicine, Vol. 158, No. 5Pulmonary blood flow distribution during partial liquid ventilationAllan Doctor, Juan C. Ibla, Barry M. Grenier, David Zurakowski, Michelle L. Ferretti, John E. Thompson, Craig W. Lillehei, and John H. Arnold1 May 1998 | Journal of Applied Physiology, Vol. 84, No. 5Distribution of inspired gas to each lung in the anaesthetised horse and influence of body shapeEquine Veterinary Journal, Vol. 27, No. 2Mechanics of the Pleural Space1 January 2011Thoracicoabdominal Mechanics During Resuscitation ManeuversChest, Vol. 84, No. 4Effect of papain-induced emphysema on the distribution of pleural surface pressureRespiration Physiology, Vol. 27, No. 1Tonic vagal influences on inspiratory durationRespiration Physiology, Vol. 24, No. 3Vertical gradients of pleural and transpulmonary pressure with liquid-filled lungsRespiration Physiology, Vol. 23, No. 2Stress-strain relationships during uniform and nona uniform expansion of isolated lungsRespiration Physiology, Vol. 23, No. 1Distribution of transpulmonary pressure and chest wall shapeRespiration Physiology, Vol. 22, No. 3The forces applied to the lung in health and diseaseThe American Journal of Medicine, Vol. 57, No. 3Continuous recording of pleural surface pressure at various sitesRespiration Physiology, Vol. 19, No. 3Local motion of the chest wall during passive and active expansionRespiration Physiology, Vol. 19, No. 1Local transpulmonary pressure after lobar occlusionRespiration Physiology, Vol. 18, No. 3Intrapulmonary Gas and Blood Flow Distribution in Awake and in Anesthetized ManSurgical Clinics of North America, Vol. 53, No. 4Regional lung volumes with positive pressure inflation in erect humansRespiration Physiology, Vol. 16, No. 3Local alveolar size and transpulmonary pressure in situ and in isolated lungsRespiration Physiology, Vol. 14, No. 3Partition of factors contributing to the vertical gradient of transpulmonary pressureRespiration Physiology, Vol. 12, No. 1Topography of pleural surface pressure during simulation of gravity effect on abdomenRespiration Physiology, Vol. 12, No. 1 More from this issue > Volume 29Issue 3September 1970Pages 297-306 https://doi.org/10.1152/jappl.1970.29.3.297PubMed5451305History Published online 1 September 1970 Published in print 1 September 1970 Metrics

Regional lung volume and pleural pressure gradient estimated from lung density in dogs.

Regional lung volume and pleural pressure gradient estimated from lung density in dogs.

Vertical gradient of alveolar size in lungs of dogs frozen intact.

Vertical gradient of alveolar size in lungs of dogs frozen intact.

Regional distribution of inspired gas in the lung.

MILK-EMILI, J., J. A. M. HENDERSON, M. B. DOLOVICH, D. TROP, AND K. KANEKO. Regional distribution of inspired gas in the lung. J. Appl. Physiol. 2 I (3) : 749-759. 1g66.-The expansion of different regions of the lungs at various lung volumes was measured in nine seated normal men, using xel? * Regional volumes (expressed as a fraction of the volume of each region at maximal inspiration) were always greater in upper than in lower lung zones. When lung volume was increased from residual volume to about 207~ vital capacity, the changes in regional lung volume (expressed as a fraction of the volume of each region at maximal inspiration) were greater in upper than in lower lung regions, whereas the opposite was true at higher lung volumes. From these data it was possible to describe systematically the effect on regional distribution of ventilation of varying both preinspiratory lung volume and tidal volume. Evidence is presented suggesting that the uneven distribution of ventilation in the normal lung is the consequence of regional differences in pleural pressure.

MEASUREMENT OF LUNG DIFFUSING CAPACITY BY MEANS OF C14O IN A CLOSED SYSTEM.

A method of measuring the lung diffusing capacity (Dl) with radioactive carbon monoxide (C14O) and nonuniformity of ventilation with nonabsorbable gas in a closed system is described. Treating ventilation as a continuous phenomenon and disregarding dead space, the mathematical equations for uniform and nonuniform ventilation (two lung regions ventilated in parallel) are derived. It is proved that sooner or later the curve for carbon monoxide, plotted on semilogarithmic paper, will be rectilinear. Experiments in six normal subjects and eight patients with chronic lung disease are described. Determinations of the distribution of the ventilation and the Dl are made in separate experiments. Since the method is unreliable at high Dl values, many of the Dl estimations are performed at high oxygen tension, which reduces the apparent Dl. It is shown that the assumption of a uniform distribution of Dl to lung volume explains the experimental findings better than the assumption of a uniform distribution of Dl to alveolar ventilation. Dl was decreased in four of the eight patients. mathematics of uniform and nonuniform ventilation; distribution of lung diffusing capacity in relation to lung volume and alveolar ventilation; N2 curve for use in calculating alveolar ventilation and regional lung volumes; CO curve for use in calculating lung diffusing capacity; diffusing capacity of lung determined with a closed system Submitted on October 15, 1962

Rate of gas absorption during atelectasis.

Rate of gas absorption during atelectasis.