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Lung Regions (lung + regions)
Selected AbstractsRegional distribution of collagen and haemosiderin in the lungs of horses with exercise-induced pulmonary haemorrhageEQUINE VETERINARY JOURNAL, Issue 6 2009F. J. Derksen Summary Reasons for performing study: Regional veno-occlusive remodelling of pulmonary veins in EIPH-affected horses, suggests that pulmonary veins may be central to pathogenesis. The current study quantified site-specific changes in vein walls, collagen and haemosiderin accumulation, and pleural vascular profiles in the lungs of horses suffering EIPH. Hypothesis: In the caudodorsal lung regions of EIPH-affected horses, there is veno-occlusive remodelling with haemosiderosis, angiogenesis and fibrosis of the interstitium, interlobular septa and pleura. Methods: Morphometric methods were used to analyse the distribution and accumulation of pulmonary collagen and haemosiderin, and to count pleural vascular profiles in the lungs of 5 EIPH-affected and 2 control horses. Results: Vein wall thickness was greatest in the dorsocaudal lung and significantly correlated with haemosiderin accumulation. Increased venous, interstitial, pleural and septal collagen; lung haemosiderin; and pleural vascular profiles occurred together and changes were most pronounced in the dorsocaudal lung. Further, haemosiderin accumulation colocalised with decreased pulmonary vein lumen size. Vein wall thickening, haemosiderin accumulation and histological score were highly correlated and these changes occurred only in the caudodorsal part of the lung. Conclusion: The colocalisation of these changes suggests that regional (caudodorsal) venous remodelling plays an important role in the pathogenesis of EIPH. Potential relevance: The results support the hypothesis that repeated bouts of venous hypertension during strenuous exercise cause regional vein wall remodelling and collagen accumulation, venous occlusion and pulmonary capillary hypertension. Subjected to these high pressures, there is capillary stress failure, bleeding, haemosiderin accumulation and, subsequently, lung fibrosis. [source] Pulmonary response to airway instillation of autologous blood in horsesEQUINE VETERINARY JOURNAL, Issue 4 2007F. J. DERKSEN Summary Reasons for performing study: Exercise-induced pulmonary haemorrhage (EIPH) occurs in the majority of horses performing strenuous exercise. Associated pulmonary lesions include alveolar and airway wall fibrosis, which may enhance the severity of EIPH. Further work is required to understand the pulmonary response to blood in the equine airways. Objectives: To confirm that a single instillation of autologous blood into horse airways is associated with alveolar wall fibrosis, and to determine if blood in the airways is also associated with peribronchiolar fibrosis. Methods: Paired regions of each lung were inoculated with blood or saline at 14 and 7 days, and 48, 24 and 6 h before euthanasia. Resulting lesions were described histologically and alveolar and airway wall collagen was quantified. Results: The main lesion observed on histology was hypertrophy and hyperplasia of type II pneumocytes at 7 days after blood instillation. This lesion was no longer present at 14 days. There were no significant effects of lung region, treatment (saline or autologous blood instillation), nor significant treatment-time interactions in the amount of collagen in the interstitium or in the peribronchial regions. Conclusion: A single instillation of autologous blood in lung regions is not associated with pulmonary fibrosis. Potential relevance: Pulmonary fibrosis and lung remodelling, characteristic of EIPH, are important because these lesions may enhance the severity of bleeding during exercise. A single instillation of autologous blood in the airspaces of the lung is not associated with pulmonary fibrosis. Therefore the pulmonary fibrosis described in EIPH must have other causes, such as repetitive bleeds, or the presence of blood in the pulmonary interstitium in addition to the airspaces. Prevention of pulmonary fibrosis through therapeutic intervention requires a better understanding of these mechanisms. [source] Iloprost inhalation redistributes pulmonary perfusion and decreases arterial oxygenation in healthy volunteersACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 9 2009D. RIMEIKA Background: Previous studies have shown that ventilation,perfusion matching is improved in the prone as compared with that in the supine position. Regional differences in the regulation of vascular tone may explain this. We have recently demonstrated higher production of nitric oxide in dorsal compared with ventral human lung tissue. The purpose of the present study was to investigate regional differences in actions by another vasoactive mediator, namely prostacyclin. The effects on gas exchange and regional pulmonary perfusion in different body positions were investigated at increased prostacyclin levels by inhalation of a synthetic prostacyclin analogue and decreased prostacyclin levels by unselective cyclooxygenase (COX) inhibition. Methods: In 19 volunteers, regional pulmonary perfusion in the prone and supine position was assessed by single photon emission computed tomography using 99mTc macro-aggregated albumin before and after inhalation of iloprost, a stable prostacyclin analogue, or an intravenous infusion of a non-selective COX inhibitor, diclofenac. In addition, gas distribution was assessed in seven subjects using 99mTc-labelled ultra-fine carbon particles before and after iloprost inhalation in the supine position. Results: Iloprost inhalation decreased arterial PaO2 in both prone (from 14.2±0.5 to 11.7±1.7 kPa, P<0.01) and supine (from 13.7±1.4 to 10.9±2.1 kPa, P<0.01) positions. Iloprost inhalation redistributed lung perfusion from non-dependent to dependent lung regions in both prone and supine positions, while ventilation in the supine position was distributed in the opposite direction. No significant effects of non-selective COX inhibition were found in this study. Conclusions: Iloprost inhalation decreases arterial oxygenation and results in a more gravity-dependent pulmonary perfusion in both supine and prone positions in healthy humans. [source] Comparison of relative forced expiratory volume of one second with dynamic magnetic resonance imaging parameters in healthy subjects and patients with lung cancer,JOURNAL OF MAGNETIC RESONANCE IMAGING, Issue 3 2005Christian Plathow MD Abstract Purpose To assess relative forced expiratory volume in one second (FEV1/vital capacity (VC)) in healthy subjects and patients with a lung tumor using dynamic magnetic resonance imaging (dMRI) parameters. Materials and Methods In 15 healthy volunteers and 31 patients with a non-small-cell lung carcinoma stage I (NSCLC I), diaphragmatic length change (LE1) and craniocaudal (CC) intrathoracic distance change within one second from maximal inspiration (DE1) were divided by total length change (LEtotal, DEtotal) as a surrogate of spirometric FEV1/VC using a true fast imaging with steady-state precession (trueFISP) sequence (TE/TR = 1.7/37.3 msec, temporal resolution = 3 images/second). Influence of tumor localization was examined. Results In healthy volunteers FEV1/VC showed a highly significant correlation with LE1/LEtotal and DE1/DEtotal (r > 0.9, P < 0.01). In stage IB tumor patients, comparing tumor-bearing with the non-tumor-bearing hemithorax, there was a significant difference in tumors of the middle (LE1/LEtotal = 0.63 ± 0.05 vs. 0.73 ± 0.04, DE1/DEtotal = 0.66 ± 0.05 vs. 0.72 ± 0.04; P < 0.05) and lower (P < 0.05) lung region. Stage IA tumor patients showed no significant differences with regard to healthy subjects. Conclusion dMRI is a simple noninvasive method to locally determine LE1/LEtotal and DE1/DEtotal as a surrogate of FEV1/VC in volunteers and patients. Tumors of the middle and lower lung regions have a significant influence on these MRI parameters. J. Magn. Reson. Imaging 2005;21:212,218. © 2005 Wiley-Liss, Inc. [source] Diagnostic accuracy of bedside ultrasonography in the ICU: feasibility of detecting pulmonary effusion and lung contusion in patients on respiratory support after severe blunt thoracic traumaACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 6 2008M. ROCCO Background: Blunt thoracic trauma is a major concern in critically ill patients. Repeated lung diagnostic evaluations are needed in order to follow up the clinical situation and the results of the therapeutic strategies. The aim of this prospective clinical study was to evaluate the possible role of lung ultrasound (LU) compared with bedside radiography (CXR) and computed tomography (CT) used as the gold standard in the evaluation of trauma patients admitted to the intensive care unit with acute respiratory failure. Method: A total of 15 thoracic trauma patients were studied at intensive care unit (ICU) arrival (T1) and 48 h later (T2) with CT, CXR and LU. We evaluated the presence of pleural effusion (PE) and lung contusion (LC). For this purpose the lung parenchyma was divided into 12 regions so that we could compare 180 lung regions at T1 and T2, respectively. Results: Sensitivity of ultrasound was 0.94 for PE and 0.86 for LC while specificity 0.99 and 0.97, respectively. The likelihood ratio was 94 (,+) and 0.06 (,,) for PE and 28.6 (,+) and 0.14 (,,) for LC. Conclusions: Ultrasound provides a reliable noninvasive, bedside method for the assessment of chest trauma patients with acute respiratory failure in the ICU. [source] Quantitative lung perfusion mapping at 0.2 T using FAIR True-FISP MRIMAGNETIC RESONANCE IN MEDICINE, Issue 5 2006Petros Martirosian Abstract Perfusion measurements in lung tissue using arterial spin labeling (ASL) techniques are hampered by strong microscopic field gradients induced by susceptibility differences between the alveolar air and the lung parenchyma. A true fast imaging with steady precession (True-FISP) sequence was adapted for applications in flow-sensitive alternating inversion recovery (FAIR) lung perfusion imaging at 0.2 Tesla and 1.5 Tesla. Conditions of microscopic static field distribution were assessed in four healthy volunteers at both field strengths using multiecho gradient-echo sequences. The full width at half maximum (FWHM) values of the frequency distribution for 180,277 Hz at 1.5 Tesla were more than threefold higher compared to 39,109 Hz at 0.2 Tesla. The influence of microscopic field inhomogeneities on the True-FISP signal yield was simulated numerically. Conditions allowed for the development of a FAIR True-FISP sequence for lung perfusion measurement at 0.2 Tesla, whereas at 1.5 Tesla microscopic field inhomogeneities appeared too distinct. Perfusion measurements of lung tissue were performed on eight healthy volunteers and two patients at 0.2 Tesla using the optimized FAIR True-FISP sequence. The average perfusion rates in peripheral lung regions in transverse, sagittal, and coronal slices of the left/right lung were 418/400, 398/416, and 370/368 ml/100 g/min, respectively. This work suggests that FAIR True-FISP sequences can be considered appropriate for noninvasive lung perfusion examinations at low field strength. Magn Reson Med, 2006. © 2006 Wiley-Liss, Inc. [source] Nitric oxide increases dramatically in air exhaled from lung regions with occluded vesselsACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 3 2003E. Fernández-Mondéjar Background:, We observed dramatic changes in exhaled nitric oxide concentration (,NOE) during wedge measurements, and hypothesised that occlusion and redistribution of pulmonary blood flow affects NOE. Methods:, We inflated the balloon of the pulmonary artery catheter and measured NOE and central hemodynamics in closed chest anesthetised pigs (n = 11) ventilated with hyperoxic gas (fraction of inspired oxygen [FIO2] = 0.5), before and during lung injury, and in open chest anesthetised pigs (n = 17) before and during left lower lobar (LLL) hypoxia (FIO2 0.05), and during hyperoxic (FIO2 0.8) ventilation of the other lung regions (HL). Results:, In the closed chest pigs NOE increased from 2.0 (0.9) to 3.4 (2.0) p.p.b. (P < 0.001) during wedge, and returned to 2.0 (1.0) p.p.b. when the balloon was deflated. The increase in mean pulmonary artery pressure (MPaP) during wedge was small and insignificant (P > 0.07). When the balloon was inflated in the right pulmonary artery in the open chest pigs, the perfusion of the HL decreased from 2.57 (0.58) to 2.34 (0.55) l min,1 (P < 0.001), and NOEHL increased from 2.5 (0.9) to 6.2 (3.2) p.p.b. (P < 0.001). The perfusion of the LLL increased from 0.33 (0.26) to 0.54 (0.34) l min,1 (P < 0.001), and NOELLL decreased from 1.7 (0.6) to 1.5 (0.5) p.p.b. (P < 0.001). Neither lung injury nor LLL hypoxia had any influence on ,NOE (P > 0.07) during wedge. The correlation coefficient (R2) was 0.66 between changes in regional blood flow and ,NOE, and 0.37 between changes in MPaP and ,NOE. Conclusions:, Nitric oxide concentration increases dramatically from lung regions with occluded vessels, whereas changes in MPaP have minor effects on NOE. This is an important fact to consider when comparing NOE within or between studies, and indicates a possible marker of diseases with occluded lung vessels. [source] Regional ventilation distribution in non-sedated spontaneously breathing newborns and adults is not differentPEDIATRIC PULMONOLOGY, Issue 9 2009Andreas Schibler MD Abstract Background: In adults, ventilation is preferentially distributed towards the dependent lung. A reversal of the adult pattern has been observed in infants using radionuclide ventilation scanning. But these results have been obtained in infants and children with lung disease. In this study we investigate whether healthy infants have a similar reverse pattern of ventilation distribution. Study Design: Measurement of regional ventilation distribution in healthy newborn infants during non-REM sleep in comparison to adults. Methods: Twenty-four healthy newborns and 13 adults were investigated with electrical impedance tomography (EIT) in supine and prone position. Regional ventilation distribution was assessed with profiles of relative impedance change. The phase lag between dependent and non-dependent ventilation was calculated as a measure of asynchronous ventilation. Results: In newborns and adults the geometric center of ventilation was centrally located in the lung at 52.2,±,6.2% from anterior to posterior and at 50.5,±,14.7%, respectively. Using impedance profiles, ventilation was equally distributed to the dependent and non-dependent lung regions in newborns. Ventilation distribution in adults was similar. Phase lag characteristics of the impedance signal showed that infants had slower emptying of the dependent lung than adults. Conclusion: The speculated reverse pattern of regional ventilation distribution in healthy infants compared to adults could not be demonstrated. Gravity had little effect on ventilation distribution in both infants and adults measured in supine and prone position. Pediatr Pulmonol. 2009; 44:851,858. © 2009 Wiley-Liss, Inc. [source] | ||||||||||