Location and mechanism of airway constriction after barium sulfate microembolism

1964 ◽  
Vol 19 (3) ◽  
pp. 387-394 ◽  
Author(s):  
J. A. Nadel ◽  
H. J. H. Colebatch ◽  
C. R. Olsen
Keyword(s):  
Histamine Release ◽  
Barium Sulfate ◽  
Transpulmonary Pressure ◽  
Smooth Muscle Contraction ◽  
Lung Compliance ◽  
Pulmonary Resistance ◽  
Airway Constriction ◽  
Large Airways ◽  
Residual Capacity ◽  
The Right

Injection of barium sulfate microemboli into the right side of the heart of paralyzed, artificially ventilated cats increased pulmonary resistance, decreased pulmonary compliance and functional residual capacity, and increased end-expiratory transpulmonary pressure and anatomic dead space. These effects could be due to constriction of terminal respiratory units without significant narrowing of the large airways, which may actually enlarge. Anatomic studies, performed after rapid freezing of the lungs in the open thorax, showed that the principal site of constriction was the alveolar ducts. Intravenous isoproterenol partially or completely prevented the changes following microembolism, suggesting that they were due to smooth muscle contraction. Vagotomy, injection of heparin or atropine or guanethedine, or inhalation of 6% carbon dioxide did not prevent the changes; prior injections of 48/80 decreased the changes. These studies suggest that the embolism-induced changes depend on histamine release. The varied manifestations of barium sulfate microembolism, including the shift of ventilation to the unaffected areas, atelectasis of embolized areas, anoxemia, and abnormal breathing pattern may depend on the presence and extent of contraction of peripheral respiratory units induced by liberation of histamine. terminal airway constriction; histamine release; lung compliance; pulmonary resistance; airway anatomy; alveolar duct; muscle Submitted on August 30, 1963

Effect of distortion on the mechanical properties of newborn piglet lung

1985 ◽  
Vol 59 (2) ◽  
pp. 434-442 ◽  
Author(s):  
K. J. Sullivan ◽  
J. P. Mortola
Keyword(s):  
Static Pressure ◽  
Transpulmonary Pressure ◽  
Lung Compliance ◽  
Newborn Piglet ◽  
Lung Collapse ◽  
Pleural Surface ◽  
Peripheral Airway ◽  
Residual Capacity ◽  
Lung Deformation ◽  
Volume History

During breathing the relatively high chest wall-to-lung compliance ratio of the newborn favors distortion of the respiratory system. In this study we have examined the effect of lung deformation, generated by a hydrostatic pleural surface pressure gradient, on the static (Cstat) and dynamic (Cdyn) compliance of the isolated newborn piglet lung. Seven lungs from piglets 2–7 days old have been studied in a saline-filled plethysmograph. Static pressure-volume (PV) curves were obtained by changing the volume a known amount and measuring the corresponding changes in transpulmonary pressure. Dynamic PV curves were obtained by ventilating the lung at a fixed pressure and at 20 cycles/min. These experiments were repeated in an air plethysmograph on the undeformed lung. Lung volume history was standardized prior to each maneuver by three inflations to 20–25 cmH2O. Lung collapse was avoided by applying an end-expiratory load equal to the transpulmonary pressure at functional residual capacity. Cstat was not significantly different between the deformed and undeformed lung (P greater than 0.05). Cdyn was less than Cstat in both cases (P less than 0.025) and was reduced further by deformation (P less than 0.05). We conclude that 1) peripheral airway obstruction or the viscoelastic properties of the piglet lung, or both, decrease Cdyn, and 2) deformation increases the external (PV) respiratory work by further decreasing Cdyn.

Lung volumes after an increase in lung distension in pneumonectomized ferrets

1989 ◽  
Vol 67 (4) ◽  
pp. 1418-1421 ◽  
Author(s):  
J. T. McBride
Keyword(s):  
Lung Resection ◽  
Transpulmonary Pressure ◽  
Tissue Growth ◽  
Lung Growth ◽  
Lung Volumes ◽  
Compensatory Lung Growth ◽  
Rubber Balloon ◽  
Residual Capacity ◽  
The Right

To investigate the role of lung distension in compensatory lung growth, the right lung of each of 21 adult male ferrets was replaced with a silicone rubber balloon filled with mineral oil. Three to thirteen weeks after surgery, the oil was removed through a subcutaneous port. Lung volumes were measured serially until 3–6 wk after balloon deflation. With pneumonectomy the total lung capacity (TLC) decreased to less than 50% of the preoperative value and remained essentially unchanged while the balloon was inflated. At balloon deflation, TLC and vital capacity did not change immediately, whereas functional residual capacity increased by 44%, indicating a change of 2–3 cmH2O in end-expiratory transpulmonary pressure. TLC increased by 10% within 3 days and continued to increase over the subsequent 3–5 wk by a total of 25% over TLC at balloon deflation. There was little difference in this response between animals whose balloons were deflated 3 wk after surgery and those in which deflation was delayed up to 13 wk. After pneumonectomy in the adult ferret, the remaining lung increases in volume in response to an increase in lung distension even weeks or months after surgery. The extent to which this volume increase involves lung tissue growth or depends on previous lung resection is at present unknown. This model may be useful for studies of the mechanisms by which lung distension influences lung volume and compensatory lung growth.

Respiratory mechanics of a small carnivore: the ferret

1982 ◽  
Vol 52 (4) ◽  
pp. 832-837 ◽  
Author(s):  
A. Vinegar ◽  
E. E. Sinnett ◽  
P. C. Kosch
Keyword(s):  
Total Lung Capacity ◽  
Lung Compliance ◽  
Pulmonary Resistance ◽  
Mustela Putorius ◽  
Tidal Breathing ◽  
Lung Capacity ◽  
Maximum Expiratory Flow ◽  
Residual Capacity ◽  
Dynamic Lung Compliance

The ferret, Mustela putorius furo, is a small relatively inexpensive carnivore with minimal housing requirements. Measurements were made from anesthetized tracheotomized supine males. Values obtained during tidal breathing for six animals (576 +/- 12 g) were as follows: tidal volume, 6.06 +/- 0.30 ml; respiratory frequency, 26.7 +/- 3.9 breaths min-1; dynamic lung compliance, 2.48 +/- 0.21 ml cmH2O-1; pulmonary resistance, 22.56 +/- 1.61 cmH2O . l–1 . s. Pressure-volume curves from nine ferrets revealed almost infinitely compliant chest walls so that lung and total respiratory system curves were essentially the same. Total lung capacity (TLC, 89 +/- 5 ml) and functional residual capacity (17.8 +/- 2.0 ml) were determined by gas freeing the lungs in vivo. The TLC of these ferrets is about the same as in 2.5-kg rabbits. Maximum expiratory flow-volume curves showed peak flows of 10.1 vital capacities (VC) . s-1 at 75% VC and flows of 8.4 and 5.4 VC . s-1 at 50 and 25% VC.

Effects of lung volume on maximal methacholine-induced bronchoconstriction in normal humans

1987 ◽  
Vol 62 (3) ◽  
pp. 1324-1330 ◽  
Author(s):  
D. J. Ding ◽  
J. G. Martin ◽  
P. T. Macklem
Keyword(s):  
Dose Response ◽  
Lung Volume ◽  
Normal Subjects ◽  
Smooth Muscle Contraction ◽  
Base Line ◽  
Pulmonary Resistance ◽  
Response Curves ◽  
Maximum Value ◽  
Residual Capacity ◽  
Normal Humans

We examined the effects of lung volume on the bronchoconstriction induced by inhaled aerosolized methacholine (MCh) in seven normal subjects. We constructed dose-response curves to MCh, using measurements of inspiratory pulmonary resistance (RL) during tidal breathing at functional residual capacity (FRC) and after a change in end-expiratory lung volume (EEV) to either FRC -0.5 liter (n = 5) or FRC +0.5 liter (n = 2). Aerosols of MCh were generated using a nebulizer with an output of 0.12 ml/min and administered for 2 min in progressively doubling concentrations from 1 to 256 mg/ml. After MCh, RL rose from a base-line value of 2.1 +/- 0.3 cmH2O. 1–1 X s (mean +/- SE; n = 7) to a maximum of 13.9 +/- 1.8. In five of the seven subjects a plateau response to MCh was obtained at FRC. There was no correlation between the concentration of MCh required to double RL and the maximum value of RL. The dose-response relationship to MCh was markedly altered by changing lung volume. The bronchoconstrictor response was enhanced at FRC - 0.5 liter; RL reached a maximum of 39.0 +/- 4.0 cmH2O X 1–1 X s. Conversely, at FRC + 0.5 liter the maximum value of RL was reduced in both subjects from 8.2 and 16.6 to 6.0 and 7.7 cmH2O X 1–1 X s, respectively. We conclude that lung volume is a major determinant of the bronchoconstrictor response to MCh in normal subjects. We suggest that changes in lung volume act to alter the forces of interdependence between airways and parenchyma that oppose airway smooth muscle contraction.

Pulmonary mechanics during the ventilatory response to hypoxemia in the newborn monkey

1983 ◽  
Vol 55 (3) ◽  
pp. 1008-1014 ◽  
Author(s):  
W. A. LaFramboise ◽  
R. D. Guthrie ◽  
T. A. Standaert ◽  
D. E. Woodrum
Keyword(s):  
Ventilatory Response ◽  
Minute Ventilation ◽  
Lung Compliance ◽  
Pulmonary Mechanics ◽  
Base Line ◽  
Respiratory Drive ◽  
Pulmonary Resistance ◽  
Residual Capacity ◽  
Dynamic Lung Compliance ◽  
Sustained Increase

Dynamic lung compliance (CL), inspiratory pulmonary resistance (RL), and functional residual capacity (FRC) were measured in 10 unanesthetized 48 h-old newborn monkeys and seven 21-day-old infant monkeys during acute exposures to an equivalent level of hypoxemia. End-expiratory airway occlusions were performed and the pressure developed by 200 ms (P0.2) was utilized as an index of central respiratory drive. P0.2 demonstrated a sustained increase throughout the period of hypoxemia on day 2 despite the fact that minute ventilation (VI) initially increased but then fell back to base-line levels. Dynamic lung compliance fell and FRC increased by 5 min of hypoxemia in the newborns. The 21-day-old monkeys exhibited a sustained increase in both VI and P0.2 throughout the hypoxic period with no change in CL and FRC. RL did not change at either postnatal age during hypoxemia. These data indicate that the neonatal monkey is subject to changes in pulmonary mechanics (decreased CL and increased FRC) during hypoxemia and that these changes are eliminated with maturation.

High-Pressure Frozen Mouse Lung: Cryo Scanning Electron Microscopy

1999 ◽  
Vol 5 (S2) ◽  
pp. 440-441
Author(s):  
Jacob Bastacky ◽  
Paul Walther ◽  
Jon Goerke ◽  
Eve Clausnitzer ◽  
Charles Lee ◽  
...  
Keyword(s):  
High Pressure ◽  
Anterior Margin ◽  
Transpulmonary Pressure ◽  
Ice Crystals ◽  
Mouse Lung ◽  
The Third ◽  
Residual Capacity ◽  
Series Of Experiments ◽  
The Right ◽  
Cryo Scanning Electron Microscopy

High-pressure facilitates freezing of biological specimens: pressurizing to 2000 bar before cooling retards growth and reduces size of ice crystals in the specimen. Although the lung is 80% air and is generally difficult to freeze, we report here good cellular ultrastructure in high-pressure frozen lung when: 1) the lung is allowed to collapse (empty of air) prior to sampling, or 2) air-filled lung is allowed to compress during pressurization in the high-pressure freezer prior to freezing or 3) airspaces are filled with relatively incompressible fluorocarbon liquid.Small Balb mice (28-30g) were anaesthetized and ventilated via endotracheal tube. The chest was opened and a 2mm diameter disk of lung at the thin anterior margin of the right lung was clamped between two aluminum tophats (200μm wells), sealing in air. In other experiments, the lung was allowed to collapse to 0 cm water transpulmonary pressure prior to clamping. In the third series of experiments, air was gradually replaced with fluorocarbon liquid (FC5312, 3M, Minneapolis MN) and the lung inflated with liquid to functional residual capacity. The top hat assembly containing the sealed lung was transferred to the high-pressure freezer (HPM 010, Bal-Tec, Balzers, Lichtenstein) where they were pressurized and frozen.

Respiratory mechanics in conscious sheep: response to methacholine

1978 ◽  
Vol 44 (3) ◽  
pp. 479-482 ◽  
Author(s):  
A. Wanner ◽  
M. E. Reinhart
Keyword(s):  
Respiratory Mechanics ◽  
Blood Gases ◽  
Lung Compliance ◽  
Base Line ◽  
Pulmonary Resistance ◽  
Arterial Blood ◽  
Pulmonary Hyperinflation ◽  
Residual Capacity ◽  
Conscious Sheep ◽  
Methacholine Provocation

Most currently used animal models of allergic airway diseases differ from human asthma in that induced bronchospasm in the former is not accompanied by pulmonary hyperinflation. In the present investigation, we chose unsedated, restrained sheep to determine the effect of cholinergic bronchial provocation on respiratory mechanics, functional residual capacity (FRC), and arterial blood gases. Seven animals had been actively sensitized by intramuscular injections of Ascaris suum extract, and four untreated animals served as controls. After inhalation of nebulized 1% methacholine solution, mean pulmonary resistance increased significantly in the sensitized sheep from a base line of 2.4 +/- 0.7 (SD) cmH2O/(l/s) to a peak value after 5 min of 7.9 +/- 4.0 cmH2O/(l/s). This was accompanied by a significant increase of mean FRC from 0.99 +/- 0.14 liters to 1.31 +/- 0.24 liters. The observed changes were transient, and after 60 min, pulmonary resistance and FRC had returned to base-line values. No significant changes occurred in static lung compliance, PaO2, PaCO2, and pH. In the control animals, methacholine provocation did not produce changes in pulmonary function. These results indicate that, in sensitized conscious sheep, induced bronchospasm is associated with pulmonary hyperinflation.

The Effect of Lobar Obstruction on Regional Perfusion in the Intact Dog

1975 ◽  
Vol 53 (5) ◽  
pp. 954-957 ◽  
Author(s):  
A. Zidulka ◽  
M. Desmeules ◽  
J. Harvey ◽  
N. R. Anthonisen
Keyword(s):  
Functional Residual Capacity ◽  
Transpulmonary Pressure ◽  
Acute Obstruction ◽  
Alveolar Pressure ◽  
Pressure Region ◽  
Residual Capacity ◽  
Xenon 133 ◽  
The Difference ◽  
The Right ◽  
Hypoxic Region

The effect of acute obstruction of the right lower lobes (RLL) on the relative perfusion of different lung regions was studied using Xenon-133 in anesthetized artificially ventilated supine dogs. When the RLL were obstructed at functional residual capacity (FRC) and the rest of the lung was inflated to a transpulmonary pressure of 10 or 20 cm H2O (1 cm H2O = 94.1 N/m2), relative perfusion increased within 10 s to the obstructed lobes by 59 and 92%, respectively. The increase was less marked but still present (17 and 42%, respectively) when obstruction was maintained for 15 min, at a time when arterial hypoxemia had occurred. Hence, there was increased perfusion to an obstructed hypoxic region. The perfusion distribution correlated with the difference in alveolar pressure between the obstructed lobes and the unobstructed lobes such that relative perfusion was always increased to the low alveolar pressure region.

Halothane anesthesia and respiratory mechanics in dogs lying supine

1980 ◽  
Vol 49 (2) ◽  
pp. 300-305 ◽  
Author(s):  
P. Southorn ◽  
K. Rehder ◽  
R. E. Hyatt
Keyword(s):  
Chest Wall ◽  
Respiratory System ◽  
Functional Residual Capacity ◽  
Respiratory Mechanics ◽  
Lung Compliance ◽  
Total System ◽  
Halothane Anesthesia ◽  
Residual Capacity ◽  
The Right

Functional residual capacity (FRC) and quasi-static deflation pressure-volume (PV) curves of the total respiratory system, lung, and chest wall were measured in eight trained dogs lying supine, first awake and then anesthetized with halothane. Two of the eight dogs were repetitively examined 10 times during a 15-mo period. FRC decreased with anesthesia in six of the eight dogs and incresed with anesthesia in the remaining two dogs. There was a significant mean anesthesia-induced reduction in FRC of 16.9% (P 〜 0.05). FRC change with anesthesia varied between studies in one of the two dogs repetitively examined. Mean PV curves of the total system, lung, and chest wall of the six dogs whose FRC decreased with anesthesia were shifted to the right by anesthesia. PV curves from the two dogs whose FRC increased with anesthesia were shifted to the left. Anesthesia produced a significant reduction (P 〜 0.05) in mean lung compliance and significant increases (P 〜0.05) in mean chest wall and total system compliances.

Effects of drug-induced pulmonary phospholipidosis on lung mechanics in rats

1989 ◽  
Vol 66 (5) ◽  
pp. 2437-2445 ◽  
Author(s):  
P. Camus ◽  
U. M. Joshi ◽  
V. G. Lockard ◽  
M. F. Petrini ◽  
D. L. Lentz ◽  
...  
Keyword(s):  
Histopathological Examination ◽  
Recovery Period ◽  
Chronic Administration ◽  
Transpulmonary Pressure ◽  
Lung Compliance ◽  
Lung Mechanics ◽  
Drug Induced ◽  
Lung Weight ◽  
Lung Volumes ◽  
Residual Capacity

Chronic administration of amphiphilic drugs to rats induces pulmonary phospholipidosis (P), a disease characterized by accumulation of phospholipids and large foamy macrophages in alveolar spaces. We investigated whether P induced by chlorphentermine (CPH) causes changes in lung volumes and mechanics in this species. Groups of rats were fed CPH (50 mg.kg-1.day-1) for 1, 2, 3, 5, 9, and 14 wk. After each treatment period, lung volumes and mechanics were studied in the anesthetized, paralyzed, supine rat. Partial pressure-volume (PV) curves were developed at 3 and 6 ml above functional residual capacity (FRC; PV3, PV6), followed by maximal [up to total lung capacity (TLC)] PV curves. FRC was determined by saline displacement. Lungs were then fixed for histopathological examination. A subgroup of animals was allowed a recovery period of 6 wk, after the 9 wk of CPH administration. Pair-fed rats served as controls (CTR) at each time point. Lung weight increased in CPH-treated (CPH-T) rats from 1.5 +/- 0.2 (SD) g at week 1 to 5.8 +/- 1.4 g at week 14, reflecting the development of P. TLC, FRC, transpulmonary pressure at FRC, the shape of maximal PV curves, and static expiratory lung compliance computed from maximal PV data points did not change in CPH-T rats. However, partial PV curves of CPH-T lungs (particularly PV3) were shifted downward and to the right of those of CTR at 2, 3, 5, and 9 wk, indicating increased recoil pressure in phospholipidotic lungs at these time points.(ABSTRACT TRUNCATED AT 250 WORDS)

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