Mild Restrictive Pattern Research Articles

Hypersensitivity pneumonitis induced by Shiitake mushroom spores

Hypersensitivity pneumonitis (HP) is a pulmonary granulomatosis involving an immunoallergic mechanism caused by chronic inhalation of antigens, most frequently organic substances, as well as chemicals. We report the first European case of hypersensitivity pneumonitis due to the inhalation of Shiitake mushroom spores. A 37-year-old French Caucasian man with a one-month history of persistent dry cough, shortness of breath and loss of weight was admitted to our hospital on December 2010. Anamnesis showed he was involved in mushroom production beginning in the summer of 2010. His temperature on admission was 36.6°C and he had a normal blood pressure (135/90 mmHg). Bilateral fine crackles were audible in the base of both lungs. Pulmonary function tests showed a mild restrictive pattern with decreased DLco and a PaO(2) of 65 mmHg, Chest CT scan revealed reticulo-nodular shadows, slight ground glass opacities, liner atelectasis, and subpleural opacities in both lung fields. Bronchoscopy was normal but cytological examination of BAL revealed a predominant lymphocytosis (55%). Serum precipitins to the Shiitake mushroom spores were positive (3 precipitins arcs with high intensity) and as a result we advised the patient to cease his mushroom production activities. The diagnosis of hypersensitivity pneumonitis due to inhalation of Shiitake mushroom spores was established as a result of the improvement of all of his clinical symptoms, i.e., cough, weight loss, bilateral fine crackles, mild restrictive pattern of pulmonary function, and reticulo-nodular shadows on chest CT, once exposure was eliminated. Recent interest in exotic mushrooms varieties, e.g., Shiitake, in developed countries because of their possible medicinal properties might increase the potential risk of HP among mushrooms workers. Therefore, healthcare professionals have to take this new potential respiratory disease into account.

Respiratory impairment and COPD hospitalisation in older persons: a competing risk analysis.

The aim of the present study was to evaluate, among older persons, the association between respiratory impairment and hospitalisation for chronic obstructive pulmonary disease (COPD), based on spirometric Z-scores, i.e. the LMS (lambda, mu, sigma) method, and a competing risk approach. Using data on 3,563 white participants aged 65-80 yrs (from the Cardiovascular Health Study) we evaluated the association of LMS-defined respiratory impairment with the incident of COPD hospitalisation and the competing outcome of death without COPD hospitalisation, over a 5-yr period. Respiratory impairment included airflow limitation (mild, moderate or severe) and restrictive pattern. Over a 5-yr period, 276 (7.7%) participants had a COPD hospitalisation incident, whereas 296 (8.3%) died without COPD hospitalisation. The risk of COPD hospitalisation was elevated more than two-fold in LMS-defined mild and moderate airflow limitation and restrictive pattern (adjusted HR (95% CI): 2.25 (1.25-4.05), 2.54 (1.53- 4.22) and 2.65 (1.82-3.86), respectively), and more than eight-fold in LMS-defined severe airflow limitation (adjusted HR (95% CI) 8.33 (6.24-11.12)). Conversely, only LMS-defined restrictive-pattern was associated with the competing outcome of death without COPD hospitalisation (adjusted HR (95% CI) 1.68 (1.22-2.32)). In older white persons, LMS-defined respiratory impairment is strongly associated with an increased risk of COPD hospitalisation. These results support the LMS method as a basis for defining respiratory impairment in older persons.

Uma doença profissional valiosa e abençoada – pneumonia organizativa devido a poeira de ouro

A 47-year-old man, restorer of religious art, presents a three week history of asthenia, myalgia, dry cough and fever, coinciding with recent, unprotected exposure, to golden dust. He had fever, crackles in lung bases, hypoxemia and elevation of inflammatory markers. Imaging studies showed areas of parenchymal consolidation with air bronchograms in posterior-basal regions of both lungs, suggesting a pneumonic process. Lung function tests: mild restrictive pattern. Bronchoalveolar lavage: lymphocytosis with low CD4/CD8 ratio. Lung biopsy: intraalveolar pneumonia with exsudative process and organization. Treatment with Prednisolone 40 mg id was started with excellent response. First month follow-up CT scan showed areas of ground glass suggesting residual pneumonitis, and he resumed normal activities with excellent exercise tolerance, under appropriate protection measures.

Presenting Features of Feather Duvet Lung

Background: Feather duvet lung (FDL) is a rare subgroup of bird fancier’s lung. It is caused by inhalation of organic dust due to goose or duck feathers in duvets or pillows. Methods: A retrospective review of the medical records of 13 patients with FDL was performed to assess the specific history and review clinical characteristics of patients with this disease. Results: All patients were female with a mean age of 53 years (26–71). They were recently exposed to feather duvets (6), pillows (1) or both (6). Specific histories were duvets or pillows filled with raw goose feathers from their own farms (4), intensive contact with goose feathers in youth (3), and bird exposure prior to symptom onset (5). In all patients specific IgG antibodies to goose and/or duck feathers were detected. Pulmonary function tests revealed a moderate to severe reduced diffusion capacity and a mild restrictive pattern. High-resolution computed tomography was performed in 11 patients and demonstrated predominantly ground-glass opacities (10) and fibrosis (6). In bronchoalveolar lavage fluid, lymphocytic alveolitis was demonstrated in all patients. Lung biopsies were obtained in 9 patients and demonstrated lymphocytic alveolitis (8), granulomas (3), bronchiolitis obliterans organizing pneumonia pattern (2), and usual interstitial pneumonia pattern (1). Conclusions: The clinical findings of FDL are typical of extrinsic allergic alveolitis. Primary sensitization could be due to former exposure to bird antigens at home or goose/duck feather exposure in youth. In view of the increasing popularity of feather duvets, FDL should be considered in the differential diagnosis of patients with extrinsic allergic alveolitis.

Closing Capacity and Gas Exchange in Chronic Heart Failure

Although it is commonly assumed that pulmonary congestion and edema in patients with chronic heart failure (CHF) promotes peripheral airway closure, closing capacity (CC) has not been measured in CHF patients. To measure CC and the presence or absence of airway closure and expiratory flow limitation (FL) during resting breathing in CHF patients. In 20 CHF patients and 20 control subjects, we assessed CC, FL, spirometry, blood gas levels, control of breathing, breathing pattern, and dyspnea. The patients exhibited a mild restrictive pattern, but the CC was not significantly different from that in control subjects. Nevertheless, airway closure during tidal breathing (ie, CC greater than functional residual capacity [FRC]) was present in most patients but was absent in all control subjects. As a result of the maldistribution of ventilation and the concurrent impairment of gas exchange, the mean (+/- SD) alveolar-arterial oxygen pressure difference increased significantly in CHF patients (4.3 +/- 1.2 vs 2.7 +/- 0.5 kPa, respectively; p < 0.001) and correlated with systolic pulmonary artery pressure (r = 0.49; p < 0.03). Tidal FL is absent in CHF patients. Mouth occlusion pressure 100 ms after onset of inspiratory effort (P0.1) as a percentage of maximal inspiratory pressure (Pimax) together with ventilation were increased in CHF patients (p < 0.01 and p < 0.005, respectively). The increase in ventilation was due entirely to increased respiratory frequency (fR) with a concurrent decrease in Paco2. Chronic dyspnea (scored with the Medical Research Council [MRC] scale) correlated (r2= 0.61; p < 0.001) with fR and P0.1/Pimax. In CHF patients at rest, CC is not increased, but, as a result of decreased FRC, airway closure during tidal breathing is present, promoting the maldistribution of ventilation, ventilation-perfusion mismatch, and impaired gas exchange. The ventilation is increased as result of increased fR, and Pimax is decreased with a concurrent increase in P0.1, implying that there is a proportionately greater inspiratory effort per breath (P0.1/Pimax). These, together with the increased fR, are the only significant contributors to increases in the MRC dyspnea score.

Rituximab Induced Interstitial Lung Disease.

Interstitial lung disease (ILD) secondary to monoclonal antibodies and tyrosine-kinase inhibitors have been reported. However, little is known about rituximab induced ILD. We report two cases of R-ILD.CASE 1: A 63 year-old man with DLBCL presented for cycle 6 of R-CHOP complaining of 10 days of dyspnea and fever. Prior to initiation of therapy, he had a normal lung exam along with computerized tomography (CT) of the chest. After three cycles of R-CHOP, repeat CT scans of the chest revealed a favorable response to treatment and continued disease-free lung fields. He had tachypnea, tachycardia, and a normal lung examination. Pulse oximetry on room air was 76%. A helical CT of the chest demonstrated diffuse bilateral pneumonitis with no evidence of pulmonary embolus. Bronchoscopy with bronchoalveolar lavage and biopsy revealed no infection. Biopsy showed evidence of alveolar damage and interstitial fibrosis. He responded to corticosteroids and was discharged home with supplemental oxygen. Two months later, he did not require supplemental oxygen. A CT scan of the chest showed almost complete resolution of his interstitial disease. Pulmonary function tests revealed a mild restrictive pattern with a severe diffusion defect.CASE 2: A 61 year-old man with DLBCL presented with 3 days of dyspnea, fever and cough. He was on cycle five, day 14 of R-CHOP. Prior to starting therapy, lung examination was normal and a CT of the chest showed no lung abnormalities. He had tachypnea, tachycardia, and inspiratory crackles on lung examination. Arterial blood gas revealed a pO2 of 45 mmHg. He was admitted to the hospital and started on broad spectrum antibiotics and corticosteroids. A helical CT of the chest revealed a diffuse interstitial lung pattern bilaterally consistent with interstitial pneumonitis and no pulmonary embolus. A bronchoscopy with bronchoalveolar lavage showed no infection. A lung biopsy could not be performed because of severe hypoxia. The patient required mechanical ventilation. After one week of intensive treatment the patient expired.DISCUSSION: Respiratory complications of rituximab include increased cough, rhinitis, brochospasm, dyspnea, and sinusitis. However, R-ILD is very rare. The pathogenesis of R-ILD is largely unknown. Potential explanations for R-ILD may include a direct injury to the lung tissues, unlikely, as well as the induction of cytotoxic substances. Rituximab acts by binding CD20+ B cells. Toxicity and efficacy are related to events after binding which include B cell signaling, complement activation, direct apoptosis, and antibody dependent cellular cytotoxicity. Complement activation and cytokine secretion, in particular, seems to be the causative factors in side effects associated with infusion reactions. Because of the increasing use of rituximab for a variety of disorders, it is important to recognize and appropriately treat possible fatal toxicities. Our patients presented with dyspnea and fever. In the absence of an infectious etiology further evaluation with a high-resolution CT scan of the chest or bronchoscopy with BAL and biopsy should be pursued. If evaluation suggests an ILD without clear evidence of infection, corticosteroids should be initiated and further treatment with rituximab discontinued.CONCLUSION: With the increasing use of rituximab and other monoclonal antibodies, clinicians must be aware of this rare but potentially fatal complication.

Factors Associated With Dyspnea in Adult Patients With Sickle Cell Disease

The aim of this prospective study was to determine the cardiorespiratory factors associated with dyspnea in patients with sickle cell SS-hemoglobin disease, with a specific interest in lung vascular involvement. Forty-nine patients (29 women and 20 men; mean [+/- SD] age: women, 29 +/- 6 years; men, 31 +/- 11 years) underwent direct evaluations (Borg scale evaluation during a 6-min walk test) and indirect evaluations (modified Medical Research Council [MRC]score) of their dyspnea, pulmonary function tests (PFTs) [spirometry, volumes, diffusing capacity of the lung for carbon monoxide (Dlco), diffusing capacity of the alveolar-capillary membrane, and pulmonary capillary blood volume measurements], echocardiography, and biological evaluation. Thirty-four patients complained of significant breathlessness (MRC score, > 1). Indirect and direct evaluations of dyspnea were correlated. PFT results depicted a very mild restrictive pattern (mean total pulmonary capacity, 86 +/- 11% predicted) and an impairment of Dlco (mean Dlco corrected for the degree of anemia, 69 +/- 13% predicted). The statistical analysis demonstrated that dyspnea and exercise performance were closely linked to indexes of Dlco but not with any echocardiographic or biological measure including anemia. Nevertheless, only approximately 25% of the variability was explained by these associations. Despite having a similar history of vasoocclusive crisis events, women had more severe anemia, dyspnea, decreases in Dlco (corrected for the degree of anemia), and a higher capillary blood volume (corrected for alveolar volume) than men. Lung vascular disease contributes to dyspnea and the exercise limitation of patients with sickle cell disease. A sequential assessment of Dlco would therefore constitute one of the objective functional end points for follow-up studies of these patients.

Alveolar‐capillary membrane conductance is the best pulmonary function correlate of exercise ventilation efficiency in heart failure patients

In heart failure (HF), changes in lung mechanics and gas diffusion are limiting factors to exercise. Their contribution to an increased exercise ventilation to CO2 production (VE/VCO2) slope is undefined. A total of 67 stable HF patients underwent cardiopulmonary exercise and pulmonary function tests, including forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1), maximal voluntary ventilation (MVV), total lung capacity (TLC) and alveolar diffusing capacity with its subcomponents (alveolar-capillary membrane conductance (D(m)) and capillary blood volume (V(c))). Patients showed a mild restrictive pattern (FEV1=85+/-15% and FVC=75+/-13% of normal predicted) and a moderate D(m) reduction (32+/-12 ml min(-1) mm Hg(-1)). Average peak VO(2) was 15.6+/-4.0 ml min(-1) kg(-1) and the VE/VCO2 slope was 39.6+/-11.0. At simple Spearman correlation analysis, all variables, but V(c), correlated with peak VO2; only D(m) correlated with VE/VCO2 slope. At partial Spearman correlation, all variables lost the peak VO2 correlation, and D(m) still inversely correlated with VE/VCO2 slope (r=-0.35; p=0.005). In patients with a high VE/VCO2 slope (cutoff value 34), despite comparable lung volumes, D(m) was significantly more depressed (30+/-13 vs. 35+/-10 ml min(-1) mm Hg(-1); p<0.01). Pulmonary function tests and alveolar gas diffusing capacity poorly correlate with peak VO2. D(m) impairment rather than lung volumes correlates with exercise ventilation efficiency. This finding further adds to the pathophysiological relevance of an abnormal gas exchange in HF patients.

Cardiopulmonary anatomy and function in long-term survivors of mild to moderate congenital diaphragmatic hernia

Background/purpose In the last decades, several studies regarding cardiopulmonary sequelae in survivors of congenital diaphragmatic hernia (CDH) have been published, but results often are conflicting, and controversies still exist. The aim of this study was to assess cardiopulmonary anatomic and functional outcome in a group of long-term survivors of CDH of mild to moderate degree. Methods Twenty-four children aged 8.15 ± 2.80 years underwent clinical examination with growth assessment, chest radiographs, echocardiography, pulmonary perfusion scintigraphy, static lung volumes measurement, and spirometry. Results Mean Z scores of weight for age and height for age were within normal values. Echocardiography showed normal anatomy and function in all but 3 patients with isolated CDH, in whom minor alterations were detected. Mean perfusion to the affected side was significantly lower (45.16 ± 5.30%; P < .0001) but still within normal range. Four children showed a substantial impairment of perfusion to the hernia side. The mean spirometric values and pulmonary volumes were normal. However, a mild restrictive pattern was evident in 6 children (27.3%), an obstructive pattern in 3 (13.6%), and a mixed obstructive and restrictive impairment in 1. Conclusions Hypoplastic lungs of mild to moderate CDH survivors continue to cause pulmonary morbidity in some children many years after the correction of the defect. In particular, lung perfusion appears to be impaired in 20% of the patients and pulmonary function in 45%, without any significant cardiac or developmental sequelae. The negative correlation between FEV 1 and duration of ventilation at presentation (r = −0.49; P = .026) may be caused by the consequences of lung hypoplasia, but initial ventilatory management may contribute to increased pulmonary morbidity. Relationship between perfusion and FEF 25–75 (r = 0.61; p = 0.004) could reflect an equivalent degree of reduction in the caliber of distal airways and pulmonary vascular tree.

SARS: prognosis, outcome and sequelae.

Severe acute respiratory syndrome (SARS) is associated with considerable morbidity and mortality in the acute phase. Worldwide case fatality rate is 11% (range 7 to 27%) for the most severely affected regions. Several adverse prognostic factors have been identified, including advanced age, presence of comorbidity, higher lactose dehydrogenase levels and initial neutrophil count, but the impact of viral and other host factors on outcome is unknown. Published data on sequelae of SARS are limited. Clinical follow‐up of patients who recovered from SARS has demonstrated radiological, functional and psychological abnormalities of varying degrees. In the early rehabilitation phase, many complained of limitations in physical function from general weakness and/or shortness of breath. In a small series of subjects who underwent CT scan of the chest, over half showed some patchy changes consistent with pulmonary fibrosis. Lung function testing at 6–8 weeks after hospital discharge showed mild or moderate restrictive pattern consistent with muscle weakness in 6–20% of subjects. Mild decrease in carbon monoxide diffusing capacity was detected in a minority of subjects. Preliminary evidence suggests that these lung function abnormalities will improve over time. Psychobehavioural problems of anxiety and/or depression were not uncommon in the early recovery phase, and improved over time in the majority of patients. Avascular necrosis of the hip has been reported as another complication. The long‐term sequelae of SARS are still largely unknown. It is important to follow up these patients to detect and appropriately manage any persistent or emerging long‐term sequelae in the physical, psychological and social domains.

Respiratory damage in children exposed to urban pollution.

Southwest Metropolitan Mexico City (SWMMC) children are chronically exposed to complex mixtures of air pollutants. In a cross-sectional arm of our study, we investigated the association between exposure to SWMMC atmosphere and nasal abnormalities, hyperinflation, and interstitial markings assessed by chest X-rays, lung function changes, several serum cytokines, and endothelin-1 in 174 children aged 5-17 years vs. 27 control children residents in low-polluted areas. Control children had no nasal lesions, and only one child showed an abnormal chest X-ray. SWMMC children exhibited nasal abnormalities (22%), hyperinflation (67%), interstitial markings (49%), and a mild restrictive pattern by spirometry (10%). Interstitial markings were associated with a decrease in predicted values of FEF(25-75), FEF(75), and the FEV(1)/FVC ratio. Boys had a higher probability of developing interstitial markings with age (P = 0.004). Blood smear findings included toxic granulations in neutrophils and schistocytes. SWMMC children had more serum IL10 and IL6 and less IL8 than controls. In a longitudinal arm of our study, we found a significant seasonal drop in FVC and FEV(1) associated with a 6-month period of high ozone and PM(10) levels. Our data strongly suggest that a lifelong exposure to urban air pollution causes respiratory damage in children. Moreover, a cytokine network becomes imbalanced, with a shift towards upregulation of anti-inflammatory cytokines. Consequently, these children are potentially at risk for developing chronic lung disease and other systemic effects later in life.

Persistent abnormal lung function after childhood empyema.

The purpose of this study was to examine pulmonary function tests in children at various time points in their recovery from empyema. Cross-sectional study. Academic Children's Hospital. Pediatric patients with a diagnosis of empyema between 1992-2000. A total of 45 pulmonary function tests were carried out in 36 study participants. Within 3 months of hospital discharge, 91% of pulmonary function tests demonstrated a restrictive pattern with a mean forced vital capacity (FVC) of 69.2 +/- 4% and a mean total lung capacity (TLC) of 74.9 +/- 4% of predicted. The incidence of restriction in pulmonary function significantly decreased over time and for patients tested > 1 year from hospital discharge the mean FVC was 87.1 +/- 2% and the mean TLC 95.0 +/- 2% of predicted. However, 19% of the patients tested > 1 year from discharge demonstrated a mild restrictive pattern and 16% demonstrated a mild obstructive changes. Patients with abnormal lung function > 1 year from hospital discharge did not demonstrate any signs or symptoms of respiratory insufficiency . There is a high incidence of restrictive patterns in lung function for children tested within 3 months from hospital discharge for empyema. The incidence of restrictive patterns decreased significantly over time and most patients tested >1 year from hospital discharge demonstrated normal lung function.

Respiratory muscle performance and the Perception of dyspnea in Parkinson's disease.

Pulmonary and respiratory muscle function impairment are common in patients with Parkinson's disease (PD). However, dyspnea is not a frequent complaint among these patients, although it is well documented that the intensity of dyspnea is related to the activity and the strength of the respiratory muscles. We studied pulmonary function, respiratory muscle strength and endurance and the perception of dyspnea (POD) in 20 patients with PD (stage II and III Hoehn and Yahr scale) before and after their first daily L-dopa dose. Respiratory muscle strength was assessed by measuring the maximal inspiratory and expiratory mouth pressures (PImax and PEmax), at residual volume (RV) and total lung capacity (TLC) respectively. The POD was measured while the subject breathed against progressive load and dyspnea was rated using a visual analog scale. Respiratory muscle strength and endurance were decreased and the POD was increased during the off medication period compared to normal subjects. There was a nonsignificant trend to an increase in Plmax, PEmax and endurance after L-dopa intake. The POD of PD patients decreased (p<0.05) following medication, although, it remained increased (p<0.01) as compared to the normal subjects. Even if patients had spirometry data showing a mild restrictive pattern, before medication, both forced vital capacity (FVC) and forced expiratory volume (FEV)1 remained almost identical after L-dopa intake. Patients with PD have higher POD, compared to normal subjects and this increased perception is attenuated when the patients are on dopaminergic medication. The change in the POD is not related to changes in respiratory muscle performance or pulmonary functions. A central effect or a correction of uncoordinated respiratory movements by L-dopa may contribute to the decrease in POD following L-dopa treatment.

Pulmonary complications after bone marrow transplantation in children: twenty-four years of experience in a single pediatric center.

In children, pulmonary sequelae contribute to early and late morbidity after bone marrow transplantation (BMT). Between 1975-1999, we performed 152 BMTs in 138 pediatric patients with malignant and nonmalignant diseases. Allogenic bone marrow was used from 99 HLA identical siblings and from 23 other related or unrelated donors. Autologous marrow was used in 30 transplantations. Median age was 8. 6 years (range, 1.1-22.4) at time of BMT. The median survival was 42%, the survival time was 6.5 years (range, 0.8-23.1), and the median follow-up time was 6.8 years (range, 0.8-23.2). Seventeen patients had severe respiratory complications. Early severe respiratory complications leading to death within the first 4 months after BMT were due to pulmonary edema (n = 1), or fungal (n = 3), bacterial (n = 1), or viral (n = 2) pneumonia. Late severe respiratory sequelae were defined as persistent respiratory symptoms for more than 4 months despite treatment, and these occurred in 10 patients, of whom 5 died. Underlying diagnoses covered a wide spectrum, including bronchiolitis obliterans (n = 3), severe restrictive lung disease (n = 2), idiopathic pneumonia syndrome (n = 3), chronic bronchitis (n = 1), and hepatopulmonary syndrome (n = 1). The overall probability for death was 0.58, and for death from severe respiratory complications, 0.16. With improved HLA matching, fewer BMTs after relapsed or primary progressive disease, and improved supportive care, including the usage of CMV negative blood products, after 1990 the probability of death from severe respiratory complications was only 0.04, whereas before 1990 it was 0.23 (P = 0.029; in each time period, n = 69). The disease spectrum has changed from initially more infectious complications to bronchiolitis obliterans and idiopathic pneumonia syndrome. Lung function measurements performed in 85 of 138 patients usually showed a mild restrictive pattern. To identify those children as early as possible who are at risk for severe respiratory complications, a close longitudinal follow-up after BMT by pediatric pulmonologists is necessary.

Anesthetic Management of the Parturient with Protein S Deficiency and Ischemic Heart Disease

Anesthetic Management of the Parturient with Protein S Deficiency and Ischemic Heart Disease

Altered lung mechanics after double-lung transplantation.

We studied lung mechanics and small airways function in 15 patients after double-lung (DL) transplantation. Patients were classified as stable (DL-S, n = 11), or having obliterative bronchiolitis syndrome (DL-OBS, n = 4). We performed pulmonary function tests (PFT), measured slope of phase 3 of the single-breath nitrogen test (N2SP3), and obtained pressure-volume curves and values: chord compliance (Cst,L), specific chord compliance (SCst,L), and elastic recoil pressure at 90% TLC. PFT showed mild restrictive pattern in DL-S and severe obstructive lung disease in DL-OBS. The N2SP3 measurement indicated small airways dysfunction in 82% of DL-S and in all DL-OBS patients. The Cst,L was 0.24 +/- 0.08 L/cm H2O in DL-S and 0.16 +/- 0.05 L/cm H2O in DL-OBS, both lower than control subjects 0.34 +/- 0. 09 L/cm H2O (p < 0.01; p < 0.001). Moreover, SCst,L was 0.09 +/- 0. 03 cm H2O-1 in DL-S, and 0.05 +/- 0.02 cm H2O-1 in DL-OBS, significantly lower than control subjects 0.12 +/- 0.02 cm H2O-1 (p < 0.05; p < 0.001). Elastic recoil at 90% TLC was normal in 14 of 15 patients. We found a linear correlation between N2SP3 and FEV1, and between FEV1 and Cst,L and SCst,L for combined DL-S and DL-OBS. Reduced compliance near FRC with normal elastic recoil at high lung volumes does not suggest changes in lung parenchyma. We speculate that structural or functional alterations in small airways may have contributed to low compliance measurements. Of special concern are our findings that DL-S had significant small airways dysfunction and reduced compliance in a pattern similar to the DL-OBS, only smaller in magnitude.

Breathing pattern and respiratory mechanics in patients with amyotrophic lateral sclerosis.

The aim of this study was to evaluate the time course of breathing pattern and respiratory mechanics in patients with amyotrophic lateral sclerosis (ALS). A study was conducted on 25 out of 38 eligible ALS patients. Neurological status, arterial blood gases (ABGs), spirometry, breathing pattern (minute ventilation (V'E), tidal volume (VT), respiratory frequency (fR), duty cycle (duration of inspiration/duration of total breathing cycle (tI/ttot)), respiratory drive (P0.1)), respiratory mechanics (oesophageal pressure (Ppl), dynamic compliance (CL,dyn), pressure time product (PTP) and index (PTI), work of breathing (WOB)), and respiratory muscle (RM) strength as assessed by maximal oesophageal pressure (Ppl,max) were evaluated at presentation (to) in all patients and after 6 months (t6) in 11 patients. At to, the mean values of the degree of neurological impairment were 60+/-20 and 103+/-30 as assessed by the Norris scale and Medical Research Council (MRC) score, respectively. From the time of the first neurological symptom, survival time ranged 7-50 months. Diurnal ABGs were normal. A mild restrictive pattern was observed, a forced vital capacity (FVC) <70% of predicted being present in 45% of patients, only FVC % pred (r=0.59; p<0.05), forced expiratory volume in one second (FEV1) % pred (r=0.53; p<0.05) and survival (r=0.64; p<0.05) showing a significant correlation with the Norris scale. A Ppl,max <30 cmH2O was associated with a significantly greater mortality, Ppl,max being correlated with survival (r=0.79, p<0.05). At t6, fR, fR/VT, P0.1/Ppl,max, were significantly increased in comparison to to, while FVC % pred, vital capacity (VC) % pred, FEV1 % pred, VT and Ppl,max were significantly reduced. These results suggest a progressive deterioration in breathing pattern and in respiratory muscle strength with progression of disease.

The Varied Manifestation of Pulmonary Artery Agenesis in Adulthood

Unilateral pulmonary artery agenesis (UPAA), a rare congenital anomaly that is frequently associated with other cardiovascular abnormalities, is usually diagnosed in childhood. Most patients who have no associated cardiac anomalies have only minor or absent symptoms and survive into adulthood. The conditions of such patients are frequently misdiagnosed in adulthood. In this report, we describe six patients with UPAA in whom the diagnosis was first established in adulthood. The varied clinical presentation of these patients is reviewed and the relative effectiveness of a variety of diagnostic tests is compared. During the period January 1987 through December 1990, six male patients, aged 17 to 20 years, were found to have UPAA at the time of their medical screening for enrollment into the armed forces. The diagnosis was based on history, clinical and imaging examinations, including chest radiography, ventilation-perfusion lung scan, digital subtraction angiography (DSA), computed tomography (CT), and magnetic resonance imaging (MRI). In four of the patients, the UPAA was on the left side and in two it was on the right. A right aortic arch was present in three patients and other cardiovascular anomalies were found in three. Pulmonary function studies showed a mild restrictive pattern in four. In contrast to previous reports, the ventilation scan showed a diminished "wash in" and "equilibrium" phase without a delayed "wash out" phase on the affected side in all patients. Selective bronchography through the fiberoptic bronchoscope revealed ipsilateral mixed-type bronchiectasis in two of four patients studied, a finding of clinical significance that has not been described previously. In all cases, the diagnosis was made by DSA. CT of the thorax (n = 6) and MRI (n = 4) were diagnostic in all cases in which they were performed, but added no significant information. UPAA is frequently misdiagnosed in adulthood and is often not considered in the differential diagnosis of the unilateral hyperlucent lung. Clinicians and radiologists should be aware of the possibility of undiagnosed cases in adults, with many atypical characteristics.

A CASE OF BARRETT ESOPHAGUS TREATED BY ESOPHAGEAL BLUNT DISSECTION WITHOUT THORACTOMY

A case of Barrett esophagus is presented. A 71-year-old man was first admitted to our hospital because of dysphagia. Two years before admission, he had complained of heartburn and epigastric pain. Endoscopy showed a hiatus hernia and gastric mucosa in the lower esophagus. Mucosal biopsy specimens revealed columnar epithelium extending upward, with no malignancy. Diagnosis of Barrett esophagus was made. He began receiving cimetidine, 800 mg/day, orally. Although the symptoms were relieved after the medical regimen, serial endoscopy showed no marked improvement but occasional ulcer formation in the columnar epithelial zone during these two years. On this admission, physical examination revealed an undernourished man in no acute distress. Laboratory studies disclosed mild anemia and mild restrictive pattern on pulmonary function test. Chest X-ray showed an old focus of tuberculosis and diffuse pleural calcification of the right lung. Upper GI series demonstrated stricutre of the lower esophagus without ulcer formation. With pulmonary complications taken into account, blunt esophageal dissection was performed without thoracotomy. The postoperative course was uneventful and the patient was discharged 40 days after surgery. Clinicopathological aspects of Barrett esophagus and its malignant potential are discussed. Blunt esophageal dissection without thoracotomy is considered a preferred treatment of choice.