Aerosol deposition in the lung with asymmetric airways obstruction: in vivo observation

1989 ◽  
Vol 67 (6) ◽  
pp. 2579-2585 ◽  
Author(s):  
C. S. Kim ◽  
M. A. Eldridge ◽  
L. Garcia ◽  
A. Wanner
Keyword(s):  
Main Bronchus ◽  
Left Lung ◽  
Aerosol Deposition ◽  
Base Line ◽  
Deposition Pattern ◽  
Before And After ◽  
Airway Obstructions ◽  
L 51 ◽  
The Right

Both the total and regional aerosol deposition were measured in six adult sheep before and after an induction of asymmetric airway obstructions, either by local instillation of carbachol solution (CS, 0.1%) distal to the right main bronchus or inhalation challenge of the right lung with carbachol aerosol (CA, 10 breaths). Total lung deposition was determined by monitoring inert monodisperse aerosols [1.0 micron mass median aerodynamic diam (MMAD)] breath-by-breath, at the mouth, by means of a laser aerosol photometer. Cumulative aerosol deposition over the first five breaths as a percent of the initial aerosol concentration (AD5) was used as a deposition index. Regional deposition pattern was determined by scintigraphic images of sulfur-colloid aerosol (1.5 microns MMAD) tagged with 99mTc. Radioactivity counts in the right (R) and left lung (L) were expressed as a percent of the whole lung count. Half-lung AD5 was then determined by multiplying AD5 by fractional radioaerosol depositions in R or L. Pulmonary airflow resistance (RL mean +/- SE), as determined by an esophageal balloon technique, increased by 111 +/- 28 and 250 +/- 96% after CA and CS, respectively (P less than 0.05). AD5 also increased in all the sheep tested by 29 +/- 3 and 52 +/- 8%, respectively, after CA and CS (P less than 0.05). Radioaerosol deposition pattern was even at base line (R/L = 51:49) but shifted toward the unchallenged L after CS (R/L = 40:60). Deposition pattern after CA was variable: a shift toward L in three, no change in one, and a shift toward the R lung in two sheep.(ABSTRACT TRUNCATED AT 250 WORDS)

Airway responsiveness to inhaled and intravenous carbachol in sheep: effect of airway mucus

1988 ◽  
Vol 65 (6) ◽  
pp. 2744-2751 ◽  
Author(s):  
C. S. Kim ◽  
M. A. Eldridge ◽  
A. Wanner
Keyword(s):  
Main Bronchus ◽  
Aerosol Deposition ◽  
Airway Responsiveness ◽  
Constant Infusion ◽  
Base Line ◽  
Flexible Fiber ◽  
Before And After ◽  
Inhalation Challenge ◽  
Airway Mucus ◽  
The Right

Excessive airway mucus can alter both the mass and site of aerosol deposition, which, in turn, may affect airway responsiveness to inhaled materials. In six prone sheep, we therefore measured pulmonary airflow resistance (RL) and cumulative aerosol deposition during five standard breaths (AD5) at base line and 3 min after inhalation challenge with 2% carbachol in buffered saline (10 breaths, tidal volume = 500 ml) or after an intravenous loading dose of carbachol (3 micrograms/kg) followed by a constant infusion of 0.3 micrograms.kg-1.min-1 with and without instillation of 20 ml of a mucus simulant (MS) into the distal end of each of the main bronchi or 30 ml of MS into the right main bronchus only by means of a flexible fiber-optic bronchoscope. Before carbachol challenge, RL did not change with MS into either both lungs or one lung only. AD5 increased from 36 +/- 2% (SE) before to 42 +/- 2% after MS instillation into both lungs (P less than 0.05) but remained unchanged after MS into one lung. After carbachol inhalation, RL increased significantly by 154 +/- 20 before and 126 +/- 25% after MS into both lungs and 162 +/- 24 before and 178 +/- 31% after MS into one lung (P less than 0.05). When the percent increase in RL was normalized for total aerosol deposition (% delta RL/AD5), the normalized values were lower after MS (3.0 +/- 0.5) than before MS (4.4 +/- 0.3) into both lungs (P less than 0.05) but were not significantly different before and after MS into the right lung only.(ABSTRACT TRUNCATED AT 250 WORDS)

Nitric oxide synthase inhibition reverses arteriolar hyporesponsiveness to endothelin-1 in septic rats

1997 ◽  
Vol 272 (3) ◽  
pp. R969-R974 ◽  
Author(s):  
S. M. Hollenberg ◽  
M. J. Piotrowski ◽  
J. E. Parrillo
Keyword(s):  
Nitric Oxide ◽  
Nitric Oxide Synthase ◽  
Cecal Ligation ◽  
Endothelin 1 ◽  
Before And After ◽  
Vasopressor Agents ◽  
Potent Vasoconstrictor ◽  
The Right ◽  
Oxide Synthase

Persistent vasodilation refractory to vasopressor agents is the hemodynamic abnormality characteristic of septic shock. Induction of nitric oxide synthase (NOS) by sepsis-induced cytokines has been hypothesized to play a pathogenetic role in this refractory vasodilation. To evaluate the mechanism of vasodilation in sepsis, we used in vivo videomicroscopy to measure responses of resistance arterioles (15-20 microm) to topical suffusion of the potent vasoconstrictor, endothelin-1 (ET-1), in rat cremaster muscle. Rats made septic by cecal ligation and puncture were compared with controls that underwent sham ligation. Responses to topically suffused ET-1 were assessed in septic and control rats before and after superfusion of the muscle with the NOS inhibitor N(G)-monomethyl-L-arginine (L-NMMA). Sepsis produced a decrease in ET-1-induced vasoconstriction; the ET-1 concentration-response curve was shifted to the right in septic rats (P < 0.05). Contractions at ET-1 concentrations of 1, 10, and 100 nM were 20, 28, and 32%, respectively, of sham controls. Superfusion of the muscle with L-NMMA restored arteriolar responsiveness to ET-1 in the septic rats, significantly increasing arteriolar constriction at 1 and 10 nM. This effect was reversed with superfusion of excess L-arginine (1 mM). This study demonstrates that impaired vasoconstriction in response to ET-1 in resistance arterioles of septic rats in vivo is reversed by NOS inhibition. Taken together with previous studies showing sepsis-induced impairment of vasoconstriction with norepinephrine, a vasopressor with a mechanism of action different from ET-1, these findings suggest a generalized abnormality in the responsiveness of resistance arterioles in sepsis. Reversal of hyporesponsiveness to both of these vasopressor agents by NOS inhibition suggests an important role for nitric oxide as a mediator of refractory vasodilation in sepsis.

Cardiovascular-associated tracheobronchial obstruction in children

2012 ◽  
Vol 23 (2) ◽  
pp. 233-238 ◽  
Author(s):  
Shen-Hao Lai ◽  
Sui-Ling Liao ◽  
Kin-Sun Wong
Keyword(s):  
Pulmonary Artery ◽  
Airway Obstruction ◽  
Main Bronchus ◽  
Main Pulmonary Artery ◽  
Diagnostic Tools ◽  
Radiographic Findings ◽  
Tracheal Compression ◽  
Airway Obstructions ◽  
Right Pulmonary Artery ◽  
The Right

AbstractTracheobronchial compression of cardiovascular origin is an uncommon and frequently unrecognised cause of respiratory distress in children. The compression may be due to encircling vessels or dilated neighbouring cardiovascular structures. Bronchoscopy and detailed radiography, especially computed tomography and magnetic resonance imaging, are among the most powerful diagnostic tools. Few previous reports have addressed the relationship between bronchoscopic findings and underlying cardiovascular anomalies. The objective of this study was to correlate bronchoscopic and radiographic findings in children with cardiovascular-associated airway obstruction. A total of 41 patients were recruited for the study. Patients with airway obstruction were stratified on the basis of the aetiology of the cardiovascular structures and haemodynamics into an anatomy-associated group and a haemodynamics-associated group. In the anatomy-associated group, stenosis and malacia were found with comparable frequency on bronchoscopy, and the airway obstructions were mostly found in the trachea (71% of patients). In the haemodynamics-associated group, malacia was the most common bronchoscopic finding (85% of patients), and nearly all locations of airway involvement were in the airway below the carina (90% of patients). The tracheal compression was usually caused by aberrant systemic branching arteries in the anatomy-associated group. In the haemodynamics-associated group, the causal relationships varied. Tracheal compression was often caused by lesions of the main pulmonary artery and aorta, whereas obstruction of the right main bronchus was caused by lesions of the main pulmonary artery and right pulmonary artery. The causes of left main bronchus compression were more diverse. In summary, the bronchoscopic presentations and locations are quite different between these two groups.

scholarly journals Successful one-lung ventilation by blocking the right intermediate bronchus in a 7-year-old child: a case report

2019 ◽  
Vol 47 (6) ◽  
pp. 2740-2745
Author(s):  
Seung Youp Baek ◽  
Jin Hwan Kim ◽  
Goo Kim ◽  
Jin Ho Choi ◽  
Chang Young Jeong ◽  
...  
Keyword(s):  
Endotracheal Tube ◽  
Main Bronchus ◽  
Left Lung ◽  
Lung Ventilation ◽  
Surgical Excision ◽  
One Lung Ventilation ◽  
Lower Lung ◽  
Endobronchial Blocker ◽  
Surgical Field ◽  
The Right

A 7-year-old child underwent surgical excision of a benign mesothelioma of the pleura near the right lower lung. Although insertion of a wire-reinforced endotracheal tube through the left main bronchus was attempted for one-lung ventilation to secure the surgical field of view, the attempt failed. Therefore, an endotracheal tube was inserted into the trachea, and an Arndt endobronchial blocker (Cook Medical, Bloomington, IN, USA) was placed in the right intermediate bronchus under bronchoscopic guidance to selectively block the right lower and middle lobes. The surgery was performed while ventilating the right upper lobe and left lung, and no specific intraoperative adverse events occurred.

Effects of indomethacin on PMA-induced pulmonary endothelial enzyme dysfunction in vivo

1992 ◽  
Vol 262 (2) ◽  
pp. L153-L162 ◽  
Author(s):  
X. Chen ◽  
S. E. Orfanos ◽  
J. D. Catravas
Keyword(s):  
Blood Flow ◽  
Left Lung ◽  
Substrate Utilization ◽  
Endothelial Damage ◽  
Metabolic Dysfunction ◽  
Before And After ◽  
Entire Lung ◽  
Metabolically Healthy ◽  
Microvascular Recruitment

We investigated the effects of phorbol myristate acetate (PMA) on metabolic pulmonary endothelial ectoenzyme dysfunction. Anesthetized rabbits were placed on total heart bypass, and the single-pass transpulmonary metabolism of [3H]benzoyl-Phe-Ala-Pro (BPAP) by endothelial-bound angiotensin-converting enzyme (ACE) and [14C]adenosine 5'-monophosphate (AMP) by 5'-nucleotidase (NCT) was calculated before and after PMA (10 micrograms/kg iv), a dose that does not produce histologically evident endothelial damage. Under conditions of partial microvascular recruitment (blood flow = 400 ml/min through the entire lung), PMA, but not the vehicle, significantly reduced substrate utilization of both BPAP and adenosine 5'-monophosphate (AMP) and increased the apparent Michaelis constant (Km) values of ACE for BPAP, indicative of metabolic dysfunction. These changes were completely prevented by pretreatment with indomethacin. Under conditions of near full microvascular recruitment (blood flow = 640 ml/min through the left lung only), PMA similarly reduced substrate utilization and increased the apparent Km of ACE for BPAP. In this case, however, indomethacin failed to prevent the observed PMA-induced metabolic dysfunction. We conclude that PMA alters endothelial ectoenzyme substrate metabolism independently from changes in pulmonary blood flow; indomethacin appears to antagonize the effects of PMA under conditions of partial microvascular recruitment only, perhaps by diverting flow to previously unperfused, unexposed to PMA, and hence metabolically healthy vessels.

Severe stenosis of a long tracheal segment, with agenesis of the right lung and left pulmonary arterial sling

2006 ◽  
Vol 16 (1) ◽  
pp. 89-91 ◽  
Author(s):  
Hamish M. Munro ◽  
Andrea M. C. Sorbello ◽  
David G. Nykanen
Keyword(s):  
Pulmonary Artery ◽  
Surgical Repair ◽  
Main Bronchus ◽  
Left Lung ◽  
Proximal Part ◽  
Pulmonary Vasculature ◽  
Severe Stenosis ◽  
Right Pulmonary Artery ◽  
Pulmonary Arterial ◽  
The Right

A baby presented at term with respiratory distress was managed with extracorporeal membrane oxygenation. Bronchoscopy revealed tracheal hypoplasia, complete tracheal rings, and agenesis of the right main bronchus. Echocardiography showed a left pulmonary arterial sling arising from the proximal part of the right pulmonary artery. Cardiac catheterization demonstrated abnormal pulmonary vasculature in the left lung which would have prevented survival, even after surgical repair. Diagnostic catheterization was important in delineating the anatomy, and aided in the decision not to proceed with surgical repair.

scholarly journals Morphological study of larynx, trachea, and lungs of Didelphis marsupialis (LINNAEUS, 1758)

2020 ◽  
Vol 13 (10) ◽  
pp. 2142-2149
Author(s):  
Bruna Tassia Santos Pantoja ◽  
Armando Reinaldo Marques Silva ◽  
Renata Mondego-Oliveira ◽  
Thamires Santos Silva ◽  
Babara Carvalho Marques ◽  
...  
Keyword(s):  
Hyaline Cartilage ◽  
Main Bronchus ◽  
Thyroid Cartilage ◽  
Left Lung ◽  
Phylogenetic Study ◽  
Thoracic Cavity ◽  
Formaldehyde Solution ◽  
Running Water ◽  
Morphological Studies ◽  
The Right

Background and Aim: From a biomedical point of view, the value of marsupials as a model of primitive mammals is indisputable. Among its species, the possum is a model that allows the study of the ontogeny of different organic systems, as well as their physiological aspects. The relevance of anatomical, functional, evolutionary, and phylogenetic study of marsupials for the development of comparative morphology is extensively documented in the literature. However, there are still many aspects to be further evaluated, as the anatomy and histology of the respiratory tract of this species. The aim of this study was to describe the morphology of the larynx, trachea, and lungs of Didelphis marsupialis. Materials and Methods: Five adult male animals were donated to the Comparative Animal Anatomy Laboratory – LAAC/ CCAA-UFMA, for morphological studies. Specimens were washed in running water to perform biometrics. Then, they were fixed with 10% formaldehyde solution. After the fixation period, the specimens were positioned in dorsal decubitus position, for dissection of the respiratory system organs, by opening the ventral region of the neck and thoracic cavity, with subsequent removal of the pectoral muscles, ribs, and sternum. For histological analysis, fragments of 1 cm2 of the larynx (epiglottis and thyroid cartilages), trachea, and lungs were collected and fixed in 10% formaldehyde solution. Right after fixation, the fragments were dehydrated in increasing concentrations of ethyl alcohol (70, 80, 95, and 100%), diaphanized in xylene, embedded in paraffin, and sectioned into thin slices of 5 μm using a microtome. Sections were stained using the hematoxylin and eosin technique. Results: Anatomically, the larynx starts right after the pharynx. It consisted of four cartilages: Epiglottis, cricoid, thyroid, and arytenoid. The trachea was made of dorsally incomplete cartilaginous rings. At the entrance of the thoracic cavity, it bifurcated into the left and right main bronchus. The left lung was smaller than the right lung, with two lobes (cranial and caudal). The right lung presents the cranial, middle, caudal, and accessory lobes. Histologically, the epiglottis consisted of elastic cartilage and is covered by a non-keratinized stratified squamous epithelium. Thyroid cartilage is made of hyaline cartilage covered by smooth muscle. The trachea presents hyaline cartilage, with ciliated pseudo-stratified epithelium, serous glands, isogenic groups of chondrocytes, and perichondrium. The lung consisted of bronchi, bronchioles, and alveoli, also presenting blood vessels and arteries. Conclusion: Morphologically, the larynx, trachea, and lungs of D. marsupialis were similar to those of the other Didelphids described in the literature.

Prenatal diagnosis of obstructive pulmonary disease: atresia of the main bronchus

2020 ◽  
Author(s):  
A.R. Sleptsov
Keyword(s):  
Prenatal Diagnosis ◽  
Pulmonary Disease ◽  
Main Bronchus ◽  
Abdominal Cavity ◽  
Left Lung ◽  
Obstructive Pulmonary Disease ◽  
The Right

A case of prenatal diagnosis of atresia of the main bronchus of the right lung at 21 weeks of gestation is presented. Right lung was increase and high echogenic. An anechogenic structure (bronchocele) was visualized in the region of the lung root. The left lung is sharply hypoplastic, the heart is shifted to the left, ascites in the abdominal cavity. Pregnancy was interrupted for medical reasons. The interest of the publication is due to the rarity of the malformation.

Lung epithelial permeability to aerosolized solutes: relation to position

1987 ◽  
Vol 62 (3) ◽  
pp. 902-911 ◽  
Author(s):  
M. Meignan ◽  
J. Rosso ◽  
R. Robert
Keyword(s):  
Left Lung ◽  
Normal Subjects ◽  
Aerosol Deposition ◽  
Gravity Gradient ◽  
Epithelial Permeability ◽  
Alveolar Volume ◽  
Lung Epithelial ◽  
Lateral Decubitus ◽  
Lung Epithelial Permeability ◽  
The Right

The lung epithelial permeability to inhaled solutes is primarily attributed to the degree of distension of the interepithelial junctions and thus of the alveolar volume. To assess this hypothesis, a submicronic aerosol of technetium-99m-labeled diethylenetriamine pentaacetate (99mTc-DTPA) was inhaled by eight normal subjects in left lateral decubitus (LLD). The regional lung clearance of 99mTc-DTPA was measured in LLD, then in right lateral decubitus (RLD) to reverse the relative distension of the alveoli. Although in LLD the deposition of the aerosol is the greatest in the gravity-dependent regions of the left lung, their 99mTc-DTPA clearances are significantly lower than those of the nondependent regions of the right lung (0.7 +/- 0.3 vs. 2 +/- 0.8%/min, P less than 0.001). In RLD, these regions placed in opposite positions significantly reversed their clearances (1.6 +/- 0.8 vs. 0.6 +/- 0.2%/min, P less than 0.001). Results indicate in lateral decubitus a gravity gradient of 99mTc-DTPA clearances independent of the aerosol deposition. This gradient of epithelial permeability to solutes appears to be influenced by the gradient of alveolar volume.

Dimethylthiourea does not ameliorate reperfusion lung injury in dogs or rabbits

1988 ◽  
Vol 65 (5) ◽  
pp. 2051-2056 ◽  
Author(s):  
M. J. Bishop ◽  
E. Y. Chi ◽  
M. Su ◽  
F. W. Cheney
Keyword(s):  
Hydroxyl Radical ◽  
Rabbit Model ◽  
Left Lung ◽  
Treated Group ◽  
Lung Edema ◽  
Activated Neutrophils ◽  
Pulmonary Arterial ◽  
Species Specific ◽  
The Right

We previously demonstrated that in vivo reperfusion of a dog lung after 48 h of pulmonary arterial (PA) ischemia results in pulmonary edema with a significant infiltrate of polymorphonuclear leukocytes. We hypothesized that the injury resulted from production of hydroxyl radical by activated neutrophils. In the current study, we attempted to prevent the injury in both dogs and rabbits with dimethylthiourea (DMTU), a scavenger of hydroxyl radical. After 48 h of left PA occlusion in 18 dogs, DMTU was administered to 9 animals and 9 were not treated. The occlusion was then released, and the dogs were killed 4 h later. Reperfusion resulted in a drop in leukocyte count and left lung edema, but there was no difference between treated and untreated animals. The wet-to-dry ratios of the lungs in the treated group were 5.76 +/- 0.44 (SE) on the reperfused left side and 4.50 +/- 0.06 (P less than 0.05) on the right side. In the untreated groups the comparable ratios were 5.73 +/- 0.31 and 4.92 +/- 0.10 (P less than 0.05 for right vs. left). Histological examination revealed significant differences between the right and left lungs in the extent of intra-alveolar granulocytes and macrophages but did not reveal differences between the treated and untreated animals. To ensure that neither the model nor the lack of response to DMTU was species specific, we then developed a rabbit model of reperfusion edema.(ABSTRACT TRUNCATED AT 250 WORDS)

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