Pulmonary function threshold for distinguishing ventilatory- and nonventilatory-limited patients with airflow obstruction

Patients with chronic obstructive pulmonary disease (COPD) may demonstrate great variability between results on the pulmonary function test (PFT) compared to those on the cardiopulmonary exercise test (CPXT). The purpose of this study was to correlate PFT and CPXT indices and to identify PFT threshold values for predicting exercise capacity in patients with airflow limitation. Fifty-seven patients (48 men and 9 women) of mean age 66.4 +/- 4.8 years with COPD and 40 age-matched control patients underwent PFT and CPXT. Based on the CPXT results, the patients were divided into ventilatory-limited (VL) and nonventilatory-limited (NVL), and the findings were correlated with the PFT indices. Linear regression analysis was used to determine the relationship between dyspnea index (VEmax/MVV) and forced expiratory volume in one second (FEV1). The cutoff value for VL was FEV1 < 38% and for NVL FEV1 > 68%. The prominent limiting symptom (61%) in the VL group was dyspnea sensation, with leg discomfort presenting in only 14%; corresponding rates in the NVL group were 38% and 31%. We conclude that the FEV1 is a reliable index for distinguishing VL from NVL COPD patients during CPXT at two extremes: below 38% of the predicted value (VL) and above 68% of the predicted value (NVL).     

Aspects of chronic airflow obstruction

This report questions several commonly used definitions and commonly accepted concepts. It suggest that the term, "chronic airflow obstructions," should replace the terms, "chronic obstructive pulmonary disease," "chronic obstructive lung disease," or "chronic airway obstruction," because it is flow that is obstructed. It is suggested the term, "chronic mucous hypersecretion," be used, rather than "chronic bronchitis," and that the latter be avoided. Chronic bronchitis should not be equated with narrowing of the airway and emphysema with loss of elastic recoil. Chronic bronchitis, emphysema, and lesions of the small airways probably occur together more frequently than chance will allow because of a common etiologic agent, tobacco smoke. Chronic mucous hypersecretion without other airway or parenchymal lesions seldom produces airflow obstruction and does not impair prognosis significantly. Central airways are important in chronic airflow obstruction. It is time that someone found out what is happening in subjects with abnormal results on tests of the function of small airways. The definition of "destruction" as it occurs in emphysema is deceptive, and loss of recoil and emphysema may be separate conditions. The dysfunction that occurs in emphysematous lungs is due mainly to associated airway lesions and may perhaps be due in part to the site and nature of emphysematous lesions (as opposed to loss of elastic recoil).     

Pulmonary Wegener's granulomatosis: changes at follow-up CT

The objective of this study was to assess the reversibility of pulmonary lesions in Wegener's granulomatosis using serial CT. We reviewed the follow-up CT scans of ten treated patients with confirmed Wegener's granulomatosis. The delay between the first evaluation before treatment and the second, on patients in clinical and biological remission, ranged from 6 to 54 months (mean 20.5 months). Follow-up CT showed a decrease in the extent of disease in all cases. Lesions disappeared completely, without scarring, in 4 of 4 ground-glass opacities, 25 of 36 nodules, and 4 of 9 pulmonary consolidations; they disappeared with residual scarring in 8 of 8 masses, 3 of 9 pulmonary consolidations, and 2 of 36 nodules. The majority of lesions disappear without scarring. Residual fibrosis may follow the occurence of masses and pulmonary consolidation. Computed tomography permits assessment of cicatricial lesions.     

Hilar cholangiocarcinoma: thin-section spiral CT findings with cholangiographic correlation

Hilar cholangiocarcinoma, a highly lethal tumor, is difficult to diagnose with conventional computed tomography (CT) because of its small size. Spiral CT allows more effective evaluation of these small lesions and better demonstrates the status of the hepatic arterial or portal venous circulation. Among 27 patients with hilar cholangiocarcinoma (infiltrative in 21, exophytic in two, polypoid in one, diffuse in three), thin-section spiral CT allowed identification of each tumor as an area of focal wall thickening that obliterated the lumen. Seventeen of the infiltrative tumors (81%) showed high attenuation. Identification of the level of biliary obstruction was possible in 63% of the patients (17 of 27). The level of obstruction was underestimated in six patients and overestimated in four. Spiral CT is a valuable method for diagnosis of hilar cholangiocarcinoma; however, spiral CT is less accurate in evaluation of intraductal tumor extent because of the limited z-axis resolution.     

The natural history of chronic airflow obstruction

A prospective epidemiological study of the early stages of the development of chronic obstructive pulmonary disease was performed on London working men. The findings showed that forced expiratory volume in one second (FEV1) falls gradually over a lifetime, but in most non-smokers and many smokers clinically significant airflow obstruction never develops. In susceptible people, however, smoking causes irreversible obstructive changes. If a susceptible smoker stops smoking he will not recover his lung function, but the average further rates of loss of FEV1 will revert to normal. Therefore, severe or fatal obstructive lung disease could be prevented by screening smokers' lung function in early middle age if those with reduced function could be induced to stop smoking. Infective processes and chronic mucus hypersecretion do not cause chronic airflow obstruction to progress more rapidly. There are thus two largely unrelated disease processes, chronic airflow obstruction and the hypersecretory disorder (including infective processes).     

Early detection of pneumonia in febrile neutropenic patients: use of thin-section CT

OBJECTIVE: The purpose of this study was to evaluate the usefulness of thin-section CT for early detection of pneumonia in neutropenic patients with an unknown site of infection and normal or nonspecific findings on chest radiographs. SUBJECTS AND METHODS: Eighty-seven patients with febrile neutropenia that persisted for more than 2 days despite empiric antibiotic treatment underwent 146 prospective examinations. If findings on chest radiographs were normal (n = 126) or nonspecific (n = 20), thin-section CT (1-mm collimation, 10-mm increment) was done. If thin-section CT scans showed opacities, bronchoalveolar lavage was recommended. RESULTS: Findings on chest radiographs were nonspecific for pneumonia in 20 (14%) of 146 cases, and CT findings in those cases were suggestive of pneumonia. Microorganisms were detected in 11 of those 20 cases. Seven of the 11 cases were not optimally treated before CT diagnosis, the other four were sufficiently treated. Findings on chest radiographs and thin-section CT scans were normal in 56 (38%) of 146 cases. In 70 (48%) of 146 cases, findings on chest radiographs were normal, whereas findings on thin-section CT scans were suggestive of pneumonia. Microorganisms were detected in 30 of the 70 cases. Nineteen of 30 cases were not optimally treated before CT, whereas the other 11 cases were sufficiently treated before CT. In 22 (31%) of these 70 cases, an opacity was observed on the chest radiograph during the 7 days after the CT study. Only three (5%) of 56 pneumonias occurred during the first 7 days after thin-section CT studies with normal findings (p < .005). Additional risk factors for pneumonia occurring later that were detectable on chest radiographs were poorly defined nodules (p < .05), consolidation (p < .05), and younger age (p < .05). CONCLUSION: Thin-section CT scans show findings suggestive of pneumonia about 5 days earlier than chest radiographs show suggestive findings. When thin-section CT scans show findings suggestive of pneumonia, the probability of pneumonia being detected on chest radiographs during the 7-day follow-up is 31%, whereas the probability is only 5% when the findings on the prior thin-section CT scan were normal (p < .005). All neutropenic patients with fever of unknown origin and normal findings on chest radiographs should be examined with thin-section CT.     

The CT findings of pulmonary sarcoidosis

Virtually every subspecialty in medicine in one way or another deals with angiogenesis-associated physiological or pathological processes and, without exception, every organ system in the body has many diseases in which angiogenesis is an important component. This in itself makes the study of angiogenesis mandatory, in both basic science and clinical settings. Yet the study of angiogenesis does not require this justification. As a biological process it is extraordinarily rich, touching on virtually every aspect of modern cell biology, making it almost impossible for molecular biologists, biochemists and morphologists to ignore. Considerable therapeutic benefit can now be obtained through positive or negative manipulation of the angiogenic process, and this is due in large part to the rapid transfer to the clinical setting of knowledge acquired through a cell biological approach.     

Automatic patient-instruction devices in thin-section CT of the thorax: impact on image quality

PURPOSE: To determine what influence automatic patient-instruction (API) devices have on image quality of chest computed tomographic (CT) scans and whether the qualitative outcome justifies their routine use. MATERIALS AND METHODS: Thin-collimation CT scans of two age- and sex-matched groups of 64 patients each were evaluated prospectively for the presence of breathing artifacts and for concomitant deterioration of image quality. Breathing commands in group 1 were given with the API device and in group 2 with technologist-performed patient instruction. Cardiac motion artifacts were not evaluated. The frequency of scans repeated owing to breathing artifact was determined. RESULTS: Image quality was worse in group 1 compared with that of group 2. The percentage of scans repeated was higher with API (38%) than without API (16%). CONCLUSION: API devices cannot be recommended for thin-section CT of the thorax. The large number of scans that must be repeated leads to a considerable increase in patient irradiation, scanning time, and cost.     

Leptomeningeal and calvarial sarcoidosis: CT and MR appearance

We report an unusual case of biopsy-proven combined leptomeningeal and calvarial sarcoidosis, as seen on CT and MRI. A solitary large thick plaque was present in the left hemisphere, with overlying bony infiltration and erosion and associated abundant vasogenic edema in the brain. The lytic lesion was visible on Scout digital radiography for CT slice positioning. The typical manifestations of CNS sarcoidosis, i.e., chronic leptomeningitis in the basilar cisterns and hypothalamic regions, were absent.     

Pulmonary intravascular tumor emboli: dilated and beaded peripheral pulmonary arteries at CT

The diagnosis of pulmonary intravascular tumor emboli is difficult to establish both clinically and on conventional radiographic studies. Between 1985 and 1991, four cases of pulmonary intravascular metastases were demonstrated on computed tomographic (CT) scans from among 14,000 CT scans of the chest. A retrospective study of these cases was performed, including a review of chest radiographs. All four patients had invasive tumors, including an atrial myxoma, a renal cell carcinoma, an osteosarcoma, and a chondrosarcoma of the pelvis. Three cases had histopathologic documentation of pulmonary artery tumor emboli. At CT, all the patients demonstrated multifocal dilatation and beading of peripheral pulmonary arteries, primarily in a subsegmental distribution involving multiple lobes. Ossification of the pulmonary arteries occurred in one case of metastatic osteosarcoma. In two cases, small, peripheral wedge-shaped opacities distal to some abnormal pulmonary arteries suggested pulmonary infarcts. The finding of dilated and beaded peripheral pulmonary arteries at CT is highly suggestive of metastatic intravascular tumor emboli.     

Grain dust-induced airflow obstruction and inflammation of the lower respiratory tract

To investigate the relationship between the physiologic and biologic effects of grain dust inhalation, we exposed 15 nonsmoking, nonasthmatic, nonatopic male grain handlers to buffered saline and aqueous corn dust extract by inhalation challenge in a crossover study. The inhalation challenges to buffered saline and corn dust extract were separated by at least 14 d. Compared with buffered saline, inhalation of corn dust extract resulted in significant airflow obstruction, which was observed within 30 min of exposure and persisted for 5 h. Inhalation of corn dust extract resulted in an acute inflammatory response characterized by higher concentrations of neutrophils (p = 0.001), IL-1 beta (p = 0.001), IL-1RA (p = 0.001), IL-6 (p = 0.001), IL-8 (p = 0.001), and TNF-alpha (p = 0.04) in bronchoalveolar lavage (BAL) fluid. mRNA levels specific for IL-1 beta, IL-1RA, IL-6, and IL-8 from cells present in the BAL fluid were significantly greater after challenge with corn dust extract than after challenge with buffered saline. Importantly, no significant differences were observed in the concentration of lymphocytes or eosinophils in the BAL fluid following inhalation of corn dust extract, and the concentrations of histamine and 15-HETE were similar in BAL fluid after the two challenges. The maximal percentage decrease in FEV1 was significantly associated with the absolute neutrophil concentration in the BAL fluid (p = 0.001), as well as the concentration of TNF-alpha (p = 0.03), IL-1 beta (p = 0.005), IL-1RA (p = 0.001), IL-6 (p = 0.001), and IL-8 (p = 0.001) in the BAL fluid.(ABSTRACT TRUNCATED AT 250 WORDS)     

Benign pulmonary nodule: morphological features and contrast enhancement evaluated with contiguous thin-section CT

The morphological changes in 54 benign lung nodules, including 8 histologically proven nodules of tuberculoma, 10 of focal organizing pneumonia (FOP), 1 of lung abscess and 35 other benign nodules, were evaluated with contiguous thin-section (3mm) CT. In addition, incremental dynamic studies were carried out in 25 of these nodules. The three-dimensional shapes of the nodules were found to be quite varied and were classified into four types: (A) round mass (n = 18), (B) polygonal mass with concave or straight margins (n = 20), (C) oval or band-like mass extending along the bronchovascular bundle (n = 7), (D) oval mass attached to the pleura with broad contact (n = 9). Forty-two (78%) of the 54 nodules were located along the bronchovascular bundle. The maximum increments in CT values over 20HU were observed after contrast enhancement in 18 (72%) of the 25 benign nodules, among which all tuberculomas showed little or no contrast enhancement. The number of small vessels quantified microscopically in teh center of the nodules were minimal in tuberculomas with little enhancement and plentiful in lesions of FOP and abscess which showed marked enhancement. Our results suggest that the differentiation between benign and malignant pulmonary nodules is not possible simply on the basis of the degree of contrast enhancement. Therefore, morphological features and the anatomical relation to the bronchovascular bundles should also be taken into consideration in the diagnosis of pulmonary nodules.     

Experimentally induced pulmonary arterial occlusion with detachable balloon in pigs: thin-section CT findings

RATIONALE AND OBJECTIVES: The authors evaluated changes of lung attenuation in pigs, with special attention to the mosaic pattern of low attenuation, at thin-section computed tomography (CT) after obstruction of the proximal pulmonary artery with a detachable balloon. MATERIALS AND METHODS: In seven pigs, nine sites of the descending pulmonary artery were obstructed with detachable balloons. This-section CT scans of the lungs were obtained immediately (n = 9) and at 1 week (n = 5), 2 weeks (n = 1), 3 weeks (n = 2), 4 weeks (n = 1), 6 weeks (n = 1), 8 weeks (n = 1), and 12 weeks (n = 1) after pulmonary artery obstruction. RESULTS: No statistically significant difference was found between the measured lung attenuation of the normal lung and that of the lung distal to the obstruction. Of the nine sites of pulmonary artery obstruction, five (56%) showed an irregular area of increased lung attenuation without lobular architecture. The diameter of the pulmonary artery after obstruction, compared with the diameter before obstruction, decreased by a range of 13%-57% (mean, 35%) and by 0-67% (mean, 44%) at levels 1 cm and 2 cm distal to the obstruction, respectively. CONCLUSION: This experimental study reveals that regional low-attenuation areas do not develop for up to 12 weeks after the obstruction of proximal pulmonary artery, despite a marked decrease in the diameter of the pulmonary artery distal to the obstruction.     

Correction of single-breath helium lung volumes in patients with airflow obstruction

STUDY OBJECTIVE: To determine whether alveolar volume (V(A)) measured during the single-breath diffusing capacity for carbon monoxide (DCO) can be used as a substitute measure for the multiple-breath total lung capacity (TLC) in subjects with and without airways obstruction. DESIGN: Retrospective review of pulmonary function test (PFT) results. SETTING: Pulmonary function laboratories at the Johns Hopkins Hospital (JHH) and the Johns Hopkins Asthma and Allergy Center (HAAC). PARTICIPANTS: Patients referred for spirometry, helium lung volumes, and Dco during a single visit between November 1993 and November 1996. RESULTS: JHAAC patients (n=2,477) were used to assess the relationship between V(A) and TLC. In patients with an FEV1/FVC > or = 0.70, there was good agreement between V(A) and TLC (V(A)/TLC=0.97 to 0.99). However, in patients with an FEV1/FVC <0.70, V(A) systematically underestimated TLC (V(A)/TLC=0.67 to 0.94). The degree of underestimation was related to the severity of airflow obstruction. To predict TLC using V(A) a regression equation was used to "correct" V(A) for the severity of obstruction. This equation was used to predict the multiple-breath TLC for JHH patients (n=2,892). Patients with an FEV1/FVC > or = 0.70 showed a high degree of correlation between V(A) and TLC (Pearson's correlation coefficient [r]=0.96 to 0.99; p<0.05). After adjusting for the severity of airflow obstruction, patients with an FEV1/FVC in the range of 0.40 to 0.70 also had a strong correlation between the corrected V(A) and the multiple-breath TLC (r=0.83 to 0.94; p<0.05). CONCLUSIONS: V(A) accurately predicts TLC in patients with mild or no airflow obstruction. For patients with moderate to severe obstruction, correcting V(A) for the severity of obstruction improves the accuracy of this relatively simple and rapid technique for measuring TLC.     

Pulmonary complications in AIDS: CT appearances

We investigated 33 cervical spinal cord injury patients (25 males and eight females) without bony injury. Patients whose neurologic recovery had reached a plateau and who had evidence on imaging of persistent spinal cord compression were considered candidates for surgical decompression. When imaging did not show spinal cord compression or patients were maintaining a good neurologic recovery from the early days after injury, we pursued conservative treatment. Age at injury varied from 20 to 76 years (mean, 55.6). Average follow-up was 31 months. Twelve patients were treated conservatively (Group 1). Groups 2 and 3 had surgery. Group 2 (14 cases) had multi-level compression of spinal cord due to pre-existing cervical spine conditions such as ossification of posterior longitudinal ligament, cervical canal stenosis, and cervical spondylosis. Group 3 (7 cases) patients existed single-level compression of spinal cord by cervical disc herniations or spondylosis. We evaluated clinical results according to the Frankel classification, the American Spinal Injury Association (ASIA) scales and Japanese Orthopaedic Association (JOA) scores. Overall improvement of JOA and ASIA scores after treatment was 56.3 +/- 35.5% and 67.1 +/- 38.0%, respectively. Patients in Group 1 showed very good recovery after conservative treatment, with improvement of JOA and ASIA scores being 70.4 +/- 40.2% and 77.4 +/- 34.2%, respectively. The average interval between injury and operation was 4.3 +/- 4.4 months. The improvement of the surgically treated patients (Groups 2 and 3) in JOA and ASIA score was 48.2 +/- 30.7% and 61.2 +/- 39.6% respectively. We obtained good neurological recovery after operation, with significantly more improvement in Group 3 than in Group 2. No significant neurologic recovery had occurred preoperatively in these groups. In such patients operative intervention is essential for neurologic recovery.     

Effect of high-dose salbutamol on cardiac rhythm in severe chronic airflow obstruction: a controlled study

Despite concern over possible adverse cardiac effects of high-dose beta-agonists there have been no controlled studies of the effects of such a therapy in patients with severe chronic airflow obstruction (CAO). We therefore studied 22 CAO patients (FEV < 1 litre) with continuous ambulatory cardiac monitoring. Patients received either nebulised salbutamol (5 mg) or saline each given 4 times daily for 24 h on 2 consecutive days, single blind, in random order. Supraventricular arrhythmias were common on both saline and salbutamol days (8 vs. 9 patients, p = NS), but none were clinically apparent. There were no episodes of ventricular tachycardia. Ventricular ectopic activity was highly variable but did not significantly differ between the two study days overall or between specific periods after nebulised salbutamol or saline. Serum potassium (mean) fell by 0.23 (SD 0.06) mmol/l in 10 patients after salbutamol. Baseline FEV1, PaO2, PCO2 were not predictive of arrhythmias or ectopic activity. While occasional adverse effects cannot be excluded, we conclude that high-dose salbutamol does not lead to any general increase in arrhythmogenic potential in severe CAO.     

Pulmonary talcosis: CT findings in three cases

OBJECTIVE: To determine the likelihood of injuries occurring to infants and children who fall out of bed. METHODS: A review of hospital records where children were documented to have fallen from a crib or bed and where the children were immediately assessed and examined following the fall. PATIENTS: Two hundred seven children younger than 6 years of age. One hundred twenty-four falls were from cribs and 83 from beds. The heights of the falls were 25 inches from beds or 41 inches when the child climbed over the bed rails and then fell, and 32 inches from cribs or 54 inches for those who fell after climbing the crib rails. RESULTS: There were 29 superficial injuries such as contusions or minor lacerations. One simple skull fracture was noted incidentally on skull roentgenogram and there was one fractured clavicle. There were no serious, multiple, visceral, or life-threatening injuries. Calculation of the momentum of impact between the injured and noninjured showed no significant difference. CONCLUSIONS: Because falls from short distances are unlikely to produce serious injury, the reliability of the history should be questioned when a child has significant injuries said to have resulted from a short fall.     

Small bowel obstruction due to phytobezoar: CT diagnosis

We report two cases of small bowel obstruction (SBO) due to phytobezoar impaction. In both cases, computed tomography (CT) demonstrated a well-defined, ovoid intraluminal mass with mottled gas pattern within the dilated small bowel at the site of obstruction and an abruptly collapsed lumen beyond the lesion. Recognition of these CT findings allows specific preoperative diagnosis of SBO owing to this uncommon lesion.     

Cytopathological analysis of sputum in patients with airflow obstruction and significant smoking histories

Advances in the understanding of lung cancer biology have led to observations that specific genetic changes occur in premalignant dysplasia. These observations have occurred predominantly in molecular studies of resected lung tumors and consequently, they may not be fully representative of those biological abnormalities characterizing premalignant lesions in individuals without overt lung cancer. Studies of premalignant epithelial cell biology and chemoprevention are needed in this patient subgroup. Such an initiative is now underway through the lung cancer Specialized Program of Research Excellence (SPORE) grant awarded to the University of Colorado Cancer Center (and affiliated institutions) by the National Cancer Institute. To identify participants for the early detection and chemoprevention trials of the Colorado SPORE, we initiated a sputum cytology screening program targeting persons with chronic obstructive pulmonary disease and smoking histories of 40 or more pack-years. During the first 26 months after activation of the screening program, sputum samples from 632 participants were evaluated. Of these, 533 (84%) of the subjects submitted specimens deemed adequate for cytopathological interpretation; 99 (16%) provided sputum samples unsuitable for cytodiagnosis. Of those participants who submitted adequate samples, 48% had cytodiagnoses of mild dysplasia, 26 % had moderate to severe dysplasia, and 2% presented with carcinoma in situ or invasive carcinoma. Logistic regression modeling was pursued to determine whether selected demographic and/or clinical status variables could be identified as statistically significant predictors of the specific cytological outcome to be expected (mild dysplasia, moderate dysplasia, and so forth). The only apparent associations found from both univariate and multivariate analyses were that the total number of pack-years of smoking history decreased with severity of cytodiagnosis and that those individuals with mild or moderate dysplasia were more likely to be ex-smokers than those with grades of regular metaplasia or lower. Based on the initial results of the Colorado SPORE sputum cytology screening program, we conclude that persons with chronic obstructive pulmonary disease and 40 or more pack-years of smoking history have a high prevalence of premalignant dysplasia detectable through sputum cytology and should be targeted for research programs focusing on lung cancer prevention, early detection, and exploratory biomarker studies.