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PubMed1994

Comparison of SPECT lung perfusion with transbronchial lung biopsy after lung transplantation.

The objective of this study was to evaluate the potential role for single photon-emission computed tomography (SPECT) using technetium 99m-macroaggregated albumin for diagnosing rejection in lung transplant patients. SPECT results were compared with those obtained from transbronchial biopsy (TBB) in patients undergoing bronchoscopy during routine surveillance and in cases of clinical, radiographic, or physiologic suspicion of lung rejection. This prospective, nonrandomized study was conducted by the Marseille Lung Transplant Group, Marseille University Hospitals South. It included 26 lung transplant recipients (19 double-lung, four single-lung, and three heart-lung). For each patient, SPECT lung perfusion was performed before TBB as part of routine surveillance protocol and when clinically indicated. Routine surveillance included TBB at 1, 3, 6, 9, and 12 months and every 6 months thereafter. SPECT was always performed within the 24 h preceding TBB. Whenever the SPECT was abnormal, biopsies were obtained from an area corresponding to a region of hypoperfusion. Results of the study were based on 79 paired SPECT and TBB obtained from 26 patients. Concordance between SPECT and biopsy occurred in 71 instances (89.9%). Among 25 cases of normal SPECT, TBB was normal in 24 and revealed subclinical lung rejection in one. Among 54 cases of abnormal SPECT, TBB was also abnormal in 47 (87.0%), with lung rejection being the abnormality in 23 (46%). For pairs performed as part of the routine surveillance protocol (61 pairs), clinically silent lung rejection was diagnosed in 16 (26.2%). SPECT was abnormal in 15 of 16 instances and normal in only one; this patient had minimal rejection that resolved without treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed2005

Donor total lung capacity predicts recipient total lung capacity after size-reduced lung transplantation.

BACKGROUND: Size-reduced lung transplantation has only recently undergone widespread use, especially in highly urgent cases. However, it is still not considered standard procedure at most centers. It has the potential to alleviate the donor organ shortage by allowing the use of oversized grafts for small and pediatric recipients. Limited data exist on pre-operative parameters predicting functional outcome after lung transplantation in general, especially after size-reduced lung transplantation. METHODS: All 98 patients undergoing primary lung transplantation during a 2-year period, including 27 size-reduced lung transplantations, were analyzed retrospectively. Pre-operative functional parameters were-after correction of estimated values according to the amount of size reduction-correlated with post-operative functional assessment. Actual and predicted total lung capacity (TLC) of transplant recipients and predicted TLC of donors was compared with the best post-operative TLC achieved within 12 months after transplantation. RESULTS: Size-reduced lung transplantation was performed in 27 cases. Downsizing was achieved by lobar transplantation (n = 9), split-lung transplantation (n = 2) or peripheral segmental resection (n = 16). There was a statistically highly significant (p < 0.01) correlation between donor TLC and best recipient TLC achieved after transplantation (Pearson's correlation coefficient = 0.675). No statistically significant correlation was seen between pre-operative recipient actual TLC and best post-operative TLC (p = 0.87; Pearson's correlation coefficient = 0.415). In standard lung transplant recipients post-operative TLC was correlated with both donor predicted TLC (p < 0.01; Pearson's correlation coefficient = 0.509) and actual pre-operative recipient TLC (p < 0.01; Pearson's correlation coefficient = 0.667). CONCLUSIONS: Post-operative recipient TLC in size-reduced lung transplantation can be predicted by donor TLC rather than pre-operative recipient TLC.

Adolescent↗
PubMed2001

Horseshoe lung: report on a new variant--"inverted" horseshoe lung--with embryological reflections on the formal pathogenesis of horseshoe lungs.

The term "horseshoe lung" is used to describe a rare congenital anomaly of the lungs that is characterized by the presence of a midline isthmus of pulmonary parenchyma connecting the posterobasal regions of the right and left lungs. Since the introduction of the term horseshoe lung in the 1960's, almost 40 cases have been reported in the literature. In all these cases, the right and left lungs were joined in their posterobasal regions, the situation resembling that found in horseshoe kidneys. Here we present a case of connection between the right and left lungs found during necropsy of a human fetus. In this case, a midline isthmus of pulmonary parenchyma covered by visceral pleura joined the apical regions of the right and left lungs behind the trachea and esophagus. This connection resulted in a "horseshoe"-shaped lung in which the "horseshoe" was turned by 180 degrees compared to classical cases of horseshoe lung. To the best of our knowledge, this is the first report on an "inverted" horseshoe lung. Embryological reflections on the formal pathogenesis of inverted and classical horseshoe lungs are presented.

Abortion, Spontaneous↗
PubMedDate not supplied

Bronchoscopy in diffuse lung disease: evaluation by open lung biopsy in nondiagnostic transbronchial lung biopsy.

Transbronchial lung biopsy through the flexible bronchoscope is used widely for the diagnosis of diffuse lung disease; however, a significant number of specimens obtained by the bronchoscopic 2-mm biopsy forceps will reveal nonspecific findings, eg, interstitial fibrosis or nonspecific pneumonitis. Such a report may be an accurate reflection of the presence of idiopathic pulmonary fibrosis or nonspecific pneumonitis, but may merely indicate that the true diagnosis has been missed. We retrospectively studied 38 patients with diffuse lung disease whose transbronchial lung biopsies yielded nonspecific abnormalities. Subsequently, these patients were subjected to open lung biopsies. Nineteen of the 38 patients (50%) had a specific diagnosis made by open lung biopsy. The diagnoses included bronchiolitis obliterans, alveolar proteinosis, metastatic carcinoma, lymphoma, tuberculosis, and bronchioloalveolar cell carcinoma. Although transbronchial lung biopsy is useful in the diagnosis of many diffuse lung diseases, it is not a replacement for open lung biopsy. When nonspecific findings by transbronchial lung biopsy do not correlate with the clinical picture, open lung biopsy should be performed.

Adolescent↗
PubMedDate not supplied

Interstitial lung disease in Japanese patients with non-small cell lung cancer receiving gefitinib: an analysis of risk factors and treatment outcomes in Okayama Lung Cancer Study Group.

UNLABELLED: Risk factors for the development of interstitial lung disease in patients with non-small cell lung cancer receiving gefitinib and the prognostic factors after interstitial lung disease development have not been established. The aim of this study was to retrospectively identify and evaluate these possible factors. PATIENTS AND METHODS: We reviewed the clinical records and radiographs of 365 consecutive patients with non-small cell lung cancer who received gefitinib in West Japan between 2000 and 2003. RESULTS: In total, 330 patients were eligible for interstitial lung disease evaluation, and 15 patients (4.5%) were finally confirmed to have developed interstitial lung disease by blinded expert review. Multivariate analysis revealed that preexisting pulmonary fibrosis, poor performance status, and prior thoracic irradiation were independent risk factors for interstitial lung disease, with odds ratios of 21.0 (95% confidence interval, 5.12-86.3, P < 0.0001), 9.70 (2.27-41.4, P = 0.001), and 4.33 (1.27-14.8, P = 0.019), respectively. Among the 15 patients who developed interstitial lung disease, eight have died of the condition. Short interval from the initiation of gefitinib treatment to the onset of interstitial lung disease, acute interstitial pneumonia pattern, and the presence of pre-existing pulmonary fibrosis were associated with poor prognosis. DISCUSSION: Our results suggest the importance of patient selection for gefitinib treatment based on interstitial lung disease risk factors in the Japanese population identified.

Adult↗
PubMed2000

[Left lung lavage affected the cardiac autonomic nervous activity more than right lung lavage during one lung ventilation in a patient with pulmonary alveolar proteinosis].

A 31-year-old man with pulmonary alveolar proteinosis underwent whole lung lavage using differential lung ventilation under general anesthesia with propofol and fentanyl. Left lung lavage was performed under the differential lung ventilation using extracorporeal lung assist. A month later, right lung lavage was performed under the differential lung ventilation alone. We compared left lung lavage with right one in the effects on heart rate variability and relationships between heart rate and arterial pressure. In the left lung lavage compared with the right one, arterial pressure was maintained higher; sympathetic nervous activity was kept tonic as shown in the power spectral analysis of heart rate variability; coherency showed lower; and a phase relationship analysis indicated a delay of almost 180 degrees. Therefore, we conclude that left lung lavage affected the cardiac autonomic nervous activity more than right one in differential lung ventilation.

Adult↗
PubMed2004

Evaluation of isolated lung perfusion as neoadjuvant therapy of lung metastases using a novel in vivo pig model: I. Influence of perfusion pressure and hyperthermia on functional and morphological lung integrity.

OBJECTIVE: Despite favorable experimental results and an encouraging early experience in humans, isolated lung perfusion (ILP) for treatment of metastases is still not established clinically. The complexity of the procedure as well as poor knowledge regarding the technical necessities of lung perfusion represents major limitations. METHODS: In this novel in vivo pig model, ILP of the left lung was performed for 40 min followed by the exclusion of the right lung. Survival and all monitored parameters of hemodynamics, ventilation and gas exchange were exclusively dependent on the previously perfused left lung for the 6-h reperfusion period. Furthermore, histological examination was assessed. In the first protocol influence of different perfusion pressures (PP) on the native lung tissue was investigated (LPG, n=6, PP<25 mmHg; HPG, n = 8, PP> or =25 mmHg). In the second protocol the influence of normothermic (T-38; n=5; t=38 degrees C), mild (T-40; n=5; t=40 degrees C) and moderate hyperthermic (T-41.5; n=5; t=41.5 degrees C) perfusion temperature was evaluated. Results were compared to those of a sham-operated control group (SG, n=5). RESULTS: ILP led to a slight deterioration of all functional as well as histological parameters in all groups. HPG resulted in impairment regarding all monitored parameters compared to LPG and SG. Significant differences between HPG and SG were found for cardiac index (P=0.026) and pulmonary vascular resistance index (PVRI, P=0.026). Histological scoring revealed significantly higher grade of lung injury for HPG animals (P=0.001). Functional parameters did not differ between normothermic and hyperthermic perfusion groups. However, animals of the T-38 group demonstrated significantly increased PVRI (P=0.004). Histological examination revealed significantly higher scores of acute lung injury for all perfusion groups compared to the Sham group (P<0.001). CONCLUSIONS: The results of this novel large animal model represent the first available demonstration that increased PP in a setting of ILP will result in deleterious effects on lung function and morphology. However, mild to moderate hyperthermia is well tolerated by the native lung tissue.

Animals↗
PubMed1990

Acute lung rejection after heart-lung transplantation: correlation of findings on chest radiographs with lung biopsy results.

This retrospective study was performed to determine if the chest radiograph could serve as a predictor for acute lung rejection in heart-lung transplantation patients. The findings on chest radiographs were correlated with the results of transbronchial biopsies in 16 heart-lung transplantation patients. The chest radiographs immediately preceding 83 biopsies were evaluated for a variety of findings. The histopathologic results of the lung biopsies were divided into five categories: (1) acute lung rejection (n = 25); (2) suggestive, but not diagnostic, of acute lung rejection (n = 8); (3) nonspecific (n = 26); (4) infection (n = 17); and (5) normal lung (n = 9). Biopsies from two patients showed both acute lung rejection and cytomegalovirus infection and were included in both categories. These histopathologic results were then correlated with the radiologic observations. We found that the combination of septal lines and new or increasing pleural effusions, without concomitant increase in cardiac size or vascular pedicle width, or evidence of vascular redistribution, indicated acute lung rejection with a sensitivity of 68% (17/25), specificity of 90% (52/58), and overall accuracy of 83% (69/83). We conclude that the chest radiograph is a useful indicator of acute lung rejection.

Adult↗
PubMed1993

Screening for lung cancer re-examined. A reinterpretation of the Mayo Lung Project randomized trial on lung cancer screening.

In the 1970s, three randomized trials, each involving approximately 10,000 male subjects, were carried out to determine the value of lung cancer screening in cigarette smokers. These studies have been widely interpreted as providing strong evidence that screening does not contribute to decreased death rates, and, accordingly, the American Cancer Society firmly recommends against lung cancer screening. No randomized trial, however, has evaluated screening for lung cancer in women, who currently comprise 39% of the lung cancer population. The trials performed at Memorial-Sloan Kettering and at Johns Hopkins were designed so that subjects were randomized to either a single screen (annual chest x-ray alone) or a dual screen (annual chest x-ray and every-4-month sputum cytology) group. While the results of both revealed no difference in mortality between the groups, these studies were designed to examine the value of sputum cytology, and no conclusion regarding the efficacy of chest x-rays can be inferred. In the Mayo Lung Project, patients were randomized to a screened group in which a chest x-ray and sputum cytology were obtained every 4 months or to a control group in which an annual chest x-ray and cytology were simply recommended. The results indicate that after 6 years, more lung cancers were detected among the 4,618 men in the screened group (206 cases, 4.46%) than in the 4,593 men in the control group (160 cases, 3.48%). The screened group showed a superiority over the control subjects in resectability rate (46% vs 32%) and 5-year survival (33% vs 15%). However, the number of cancer deaths was slightly greater in the screened (122) than in the control group (115), and, consequently, the mortality rates were not significantly different among the groups. An "overdiagnosis bias" has been suggested to account for the increased number of lung cancers detected in the screened vs the control population in the Mayo Lung Project. This explanation is statistically plausible, but, given the status of lung cancer as the most lethal of malignancies, is biologically unlikely. An alternative hypothesis is that chance alone might have accounted for the observed 0.98% difference in lung cancer detection rates. Were this the case, then 46 additional cases would have been detected in the control group had this chance event not occurred.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗
PubMed1989

Lung density changes observed in vivo in rat lungs after irradiation: variations among and within individual lungs.

Lung density measurements using Computed Tomography have been used before at various intervals after irradiation to monitor radiation-induced changes in the lung. The average lung density, its standard deviation which was used as a measure of the density homogeneity throughout the lung, and the densities of smaller lung regions were measured before and up to 76 weeks after irradiation in rat lungs. Large differences in individual response to irradiation were observed. Both increases and decreases in lung density were measured. Regions of very low density were often found adjacent to dense foci of radiation damage. These compensatory changes made the measurement of changes in average lung density an insensitive index of radiation damage. However, the measurement of regional densities in smaller lung volumes, a method not previously applied to rodents, was a much more sensitive index of radiation damage. Changes from non-irradiated control lung densities were observed at earlier times and for lower radiation doses.

Absorptiometry, Photon↗
PubMed1987

Unilateral paraquat-induced lung fibrosis: evolution of changes in lung fibronectin and collagen after graded degrees of lung injury.

We describe a model of pulmonary fibrosis in which doses of paraquat ranging from 0.001 mg/kg to 1.0 mg/kg were instilled into the right lung of rats. Lung injury, as measured by right lung lavage albumin content and differential neutrophil count, ranged from undetectable to extremely severe, depending on the dose. Lung fibrosis, as assessed by collagen content and electron microscopy, showed similar dose-response effects. Mortality was minimal. Lavage fibronectin increased after high doses of paraquat, peaked at 2 d postinjury, decreased sharply after 3 d and was normal by 7 d. The temporal pattern was similar to that for albumin. Cultured alveolar macrophages obtained at 4 d postinjury did not have significant increases in fibronectin release. Tissue fibronectin content increased more slowly than lavage fibronectin, peaking at 4 d postinjury, and was still elevated at 7 and 14 d postinjury. Incorporation of [35S]methionine into tissue fibronectin by lung explants obtained at different times postinjury showed a similar time course. Lung collagen content increased steadily between 4 and 14 d postinjury. We conclude that, in our model, graded degrees of lung injury and fibrosis can be produced by varying the dose of unilaterally instilled paraquat and that the increases in lavage fibronectin were related mainly to capillary permeability whereas increases in tissue fibronectin represented parenchymal synthesis. The time course of changes in lung tissue fibronectin and collagen was consistent with the proposed roles of fibronectin in tissue repair and fibrosis. The ability of our model to produce graduated degrees of lung injury and fibrosis should be useful in further studies on the pathogenesis of postinjury lung fibrosis.

Albumins↗
PubMed1976

Transbronchial biopsy for the diagnosis of lung transplant rejection. Comparison with needle and open-lung biopsy techniques in canine lung allografts.

The accurate diagnosis of lung transplant rejection requires histologic examination of the grafted lung. Because transbronchial lung biopsy has been advocated as an effective diagnostic procedure for a variety of lung diseases, it was elected to assess this technique in rejecting transplanted lungs. Twenty-two dogs received allografts and underwent simultaneous lung biopsy by 3 techniques when signs of rejection occurred. Open lung biopsy was diagnostic of rejection in all instances. Transthoracic needle biopsy correlated with the open biopsy in 59 per cent of the cases. No specimen obtained by transbronchial lung biopsy provided sufficient material to permit fulfillment of the strict histologic criteria needed to diagnose allograft rejection. Although transbronchial lung biopsy is successful in many pulmonary infiltrative processes, it appears to be inadequate for the diagnosis of lung allograft rejection.

Animals↗
PubMed1993

Comparison of video thoracoscopic lung biopsy to open lung biopsy in the diagnosis of interstitial lung disease.

BACKGROUND: Up to one third of patients with interstitial lung disease will require a lung biopsy for diagnosis. Open lung biopsy is generally accepted as the most reliable method of biopsy and tissue diagnosis. The purpose of this study was to compare the efficacy and safety of video thoracoscopic lung biopsy, a minimally invasive technique, with open lung biopsy in the diagnosis of interstitial lung disease. METHODS: From December 1990 to January 1992, 43 patients were referred for diagnostic lung biopsy. Twenty-two consecutive patients undergoing video thoracoscopic lung biopsy (VTLB) over a 6-month period were retrospectively studied and compared with 21 consecutive patients who had undergone open lung biopsy (OLB) in the preceding 6-month period. RESULTS: VTLB (46 +/- 4 minutes) did not add to operative time when compared with OLB (38 +/- 3 min, p = 0.09). The same number of biopsies per patient were performed (VTLB, 1.9 +/- 0.1; OLB, 2.0 +/- 0.1; p = 0.48), the same amount of tissue was obtained per biopsy (VTLB, 6.69 +/- 0.82 cm3; OLB, 5.78 +/- 0.54 cm3; p = 0.36), and the diagnostic accuracy of each method was comparable (VTLB, 95 percent; OLB, 100 percent). However, patients undergoing VTLB demonstrated a significant reduction in length of pleural drainage (1.36 +/- 0.25 days) and hospital stay (2.57 +/- 0.46 days) relative to patients undergoing OLB (3.20 +/- 0.34 days, 5.71 +/- 0.63 days; p < 0.05). Complications occurred in 2/22 VTLB patients (9 percent, 0 deaths) and 4/21 OLB patients (19 percent, 1 death). CONCLUSIONS: When compared with OLB, VTLB does the following: (1) provides equivalent specimen volume; (2) achieves equal diagnostic accuracy; (3) does not add to operative time or complications; and (4) reduces the time necessary for pleural drainage and length of hospital stay. Our findings suggest that VTLB is an effective and safe alternative to OLB in the diagnosis of interstitial lung disease.

Adult↗
PubMed2003

[Expression of a new lung cancer drug resistance-related gene in lung cancer tissues and lung cancer cell strains].

BACKGROUND & OBJECTIVE: A new drug resistance-related gene fragment which was 494 bp long was found using suppression subtractive hybridization (SSH) and its full-length cDNA fragment was cloned by the authors. This study was designed to determine the expression of this lung cancer drug resistance-related gene (LCDRG) in lung cancer tissues, juxtacancerous tissues, and five lung cancer cell strains. METHODS: The expression of LCDRG was determined by semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR) method in 38 lung cancer tissues,12 juxtacancerous tissues, and 5 lung cancer cell strains. RESULTS: The expression of LCDRG in cancer tissues was significantly higher than that in juxtacancerous tissue (P< 0.001). There was no significance of the expression among adenocarcinoma, brochioloalveolar carcinoma, and squamous carcinoma. In lung cancer cell strains, the expression levels of LCDRG in adenocarcinoma cell strains SPC-A-1 and A549, big cell lung cancer cell strain H460, small cell lung cancer cell strains H446 and SH77 were decreased gradually. CONCLUSION: LCDRG is closely related to lung cancer and may be involved in the pathogenesis of lung cancer.

Adult↗
PubMed2000

Diuretics acting on the distal renal tubule for preterm infants with (or developing) chronic lung disease.

OBJECTIVES: The aim of this review is to assess the risks and benefits of diuretics acting on distal segments of the renal tubule (distal diuretics) in preterm infants with or developing chronic lung disease (CLD). Primary objectives are to assess changes in need for oxygen or ventilatory support and effects on long-term outcome, and secondary objectives are to assess changes in pulmonary mechanics and potential complications of therapy. SEARCH STRATEGY: We used the standard method of the Cochrane Neonatal Review Group. We used the following keywords: ¿ or ¿ and , limited to and limited to or . We searched Medline (1966-1998), Embase (1974-1998) and the Cochrane Controlled Trials Register (CCTR) from the Cochrane Library (1999, issue 2). In addition, we hand searched several abstract books of national and international American and European Societies. SELECTION CRITERIA: We included in this analysis trials in which preterm infants with or developing CLD and at least five days of age were all randomly allocated to receive a distal diuretic (i.e., a diuretic acting on the distal renal tubule). Eligible studies needed to assess at least one of the outcome variables defined a priori for this systematic review. Primary outcome variables included changes in need for respiratory support and oxygen supplementation, mortality, bronchopulmonary dysplasia (BPD), death or BPD, chronic lung disease at 36 weeks of postconceptional age (gestational age + postnatal age), length of stay, and number of rehospitalizations during the first year of life. Secondary outcome variables included pulmonary mechanics and potential complications of therapy. DATA COLLECTION AND ANALYSIS: We used the standard method for the Cochrane Collaboration which is described in the Cochrane Collaboration Handbook. Two investigators extracted, assessed and coded separately all data for each study, using a form that was designed specifically for this review. Any disagreement was resolved by discussion. We combined parallel and cross-over trials and, whenever possible, transformed baseline and final outcome data measured on a continuous scale into change scores using Follmann's formula. MAIN RESULTS: Of six studies fulfilling entry criteria, most focused on pathophysiological parameters and did not assess effects on important clinical outcomes defined in this review, or the potential complications of diuretic therapy. In preterm infants > 3 weeks of age with CLD, a four-week treatment with thiazide and spironolactone improved lung compliance and reduced the need for furosemide. Thiazide and spironolactone decreased the risk of death and tended to decrease the risk for lack of extubation after 8 weeks in intubated infants. There is no evidence to support the hypothesis that adding spironolactone to thiazide or that adding metolazone to furosemide improves the outcome of preterm infants with CLD. REVIEWER'S CONCLUSIONS: In preterm infants > 3 weeks of age with CLD, acute and chronic administration of distal diuretics improve pulmonary mechanics. Chronic administration of diuretics (thiazide with spironolactone) reduces mortality in intubated patients. Large studies are needed to assess (1) whether chronic diuretic administration improves mortality, duration of oxygen dependency, ventilator dependency, length of hospital stay and long-term outcome in patients without long-term toxicity and (2) whether adding spironolactone to thiazides or adding metolazone to furosemide has any beneficial effect.

Chronic Disease↗
PubMed2001

Speed of collapse of the non-ventilated lung during single-lung ventilation for thoracoscopic surgery: the effect of transient increases in pleural pressure on the venting of gas from the non-ventilated lung.

A study of 10 anaesthetised patients placed in the lateral position for thoracoscopic surgery assessed whether transient increases in pleural pressure on the side of the non-ventilated lung might increase the speed at which gas vents from that lung. The transient increases in pleural pressure were generated by the mediastinal displacement that occurs with each inspiratory phase of positive pressure ventilation of the dependent lung. When combined with a unidirectional valve allowing gas to flow out of the non-ventilated lung, and a second valve allowing ambient airflow into, but not out of, the thoracic cavity via an initial thoracoscopy access site, this mediastinal displacement could conceivably serve to 'pump' gas out of the non-ventilated lung. Using the four different combinations of valve inclusion or omission, the volume of gas that vented from the non-ventilated lung into a measuring spirometer was recorded during a 120-s measurement sequence. It was found that the speed of venting was not increased by the transient increases in pleural pressure, and that in all but one of a total of 34 measurement sequences, venting had ceased by the end of the sequence. Gas venting was a mean (SD) of 85.5 (11.9)% complete in 25 s (five breaths), and 96.6 (6.1)% complete in 60 s. This prompt partial lung collapse very likely reflected the passive elastic recoil of the lung, while the failure of transient increases in pleural pressure to result in ongoing venting of gas was probably a consequence of airways closure as the lung collapsed. It is concluded that techniques that aim to speed lung collapse by increasing pleural pressure are unlikely to be effective.

Adolescent↗
PubMed1996

Effects of lung expansion on lung liquid production in vitro by lungs from fetal guinea-pigs. I. Basic studies and the effects of amiloride and propranolol.

Lungs from near-term fetal guinea-pigs were supported in vitro for 3 h; lung liquid production was measured by a dye-dilution method using Blue Dextran 2000 (fetuses 62 +/- 2 days of gestation, 97.6 +/- 19.0 (SD) g body weight; n = 134). Untreated control preparations produced fluid at 1.30 +/- 0.22 ml/kg body weight per h, and showed no significant changes during incubation (n = 30). After 1 h of incubation, experimental lungs were expanded with Krebs-Henseleit saline in volumes estimated to be below or approximating those of the first breath (n = 30; first breath, 0.6-1.2 ml). Expansions were graded at 18 +/- 4%, 31 +/- 4%, 43 +/- 3%, 50 +/- 3% and 72 +/- 2% of lung volume (volumes used for expansion at the maximal level, 0.64 +/- 0.25 ml). All expansions of 31% or above produced reductions in fluid production significant by analysis of variance (P < 0.01-0.001); production halted at 50% expansion, and there was strong reabsorption at 72% expansion (-0.87 +/- 0.45 ml/kg body weight per h by the final hour). There was an exponential relationship between percentage expansion and percentage fall in production (r = 1.00). There was no evidence for excessive pressure, and no evidence for lung damage as judged by electron microscopy or entry of intracellular materials into the fluid (lactic dehydrogenase, protein, K+). In studies based on 36 preparations, 10(-6) M amiloride present in the lung lumen (apically) abolished the reabsorptions seen at 70 +/- 3% expansion, but not the arrest of production; it had no effect on control preparations. Studies based on 24 preparations showed that responses to 72 +/- 2% expansion were not affected by 10(-7) M propranolol placed in the outer saline. In studies of 14 fetuses of widely different body weights (68.3-124.9 g), responses to 74 +/- 2% expansion showed an exponential increase with increasing body weight (r = 0.96). Although caution is needed, the results suggest that expansion of the lungs at birth may induce fluid reabsorption by an action independent of tissues outside the lungs, probably involving both activation of a Na(+)-based reabsorptive system and arrest of production, but not requiring beta-receptor activation. The probability that the responses are maximal at birth is discussed, and it is suggested that the effect of expansion may be a specialization of the perinatal lung.

Amiloride↗
PubMed2005

[The effect of body position changes on lung function, lung CT imaging and pathology in an oleic acid-induced acute lung injury model].

OBJECTIVE: To study the effect of body position changes on lung mechanics, oxygenation, CT images and pathology in an oleic acid-induced acute lung injury (ALI) model. METHODS: The study groups consisted of one control group and three experimental groups in which the rabbits were put on supine, prone and rotation, respectively. The changes of partial pressure of arterial oxygen (PaO(2)), lung mechanics in the course of the experiment, as well as lung CT and pathology were observed and analyzed. RESULTS: PaO(2) and lung compliance of the prone and the rotation rabbits were higher than those of the supine rabbits [(158 +/- 51) mm Hg, (166 +/- 37) mm Hg, (87 +/- 24) mm Hg; (2.8 +/- 0.9) ml/cm H(2)O, (2.6 +/- 0.7) ml/cm H(2)O, (1.6 +/- 0.5) ml/cm H(2)O, respectively, all P < 0.05], while intrapulmonary shunt was significantly less in the prone and the rotation groups. The airway peak inspiration pressure of the rotation rabbits was higher than that of the prone rabbits [(20 +/- 2) cm H(2)O, (16 +/- 2) cm H(2)O, P < 0.05]. PaO(2) was positively correlated to the lung compliance and negatively correlated to the intrapulmonary shunt. Oleic acid-induced ALI lung CT was divided into dependent region and nondependent region, and the CT changes of the two regions were rapid after position change. The distribution of lung edema was affected by gravitation. CONCLUSIONS: Prone and rotation positions can improve oxygenation in this ALI model. Continuous rotation can relieve the extent of compressive lung collapse which occurs in ALI.

Animals↗