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PubMed1995

Efficacy of tracheal and bronchial stent placement on respiratory functional tests.

Stent placement is the only available treatment in patients presenting either a localized external compression or a malacia of the tracheobronchial tree. To assess the functional benefit of prosthesis insertion in these indications, we compared functional respiratory values before, immediately after (48 h), and at sometime after (mean, 10.1 months) operation in 24 patients presenting with a bronchial lesion (B group, n = 5) or a lesion of the intrathoracic part (ITT group, n = 9) or of the extrathoracic part of the trachea (ETT group, n = 10). Before treatment, airflow was severely impaired in most patients without significant differences among the groups. After prosthesis insertion, airflow parameters increased [change in forced expiratory volume in 1 s (delta FEV1 = 440 mL; delta peak expiratory flow (PEF) = 0.92 L.s-1; delta maximum expiratory flow 25/75 (delta MEF25/75) = 0.47 L.s-1; and delta forced inspiratory volume in 1 s (delta FIV1 = 310 mL)] and airway resistances (Raws) decreased (delta Raw = -0.43 kPa.s-1.s-1) without any significant variation in either forced vital capacity (FVC) or total lung capacity. Airflow improvement was more apparent in ITT and ETT groups than in the B group. Moreover, inspiratory flow increase and decrease of FEV1/PEF ratio were only observed in the ETT group. This airflow improvement was maintained for a long time after and was associated with a good clinical tolerance. This study supports the clinical and functional benefits of prosthesis placement both in benign and malignant airway compressions for palliative treatment.

Adult↗
PubMed2002

Unsuspected loss of lung elastic recoil in chronic persistent asthma.

STUDY OBJECTIVES: To investigate the progression and mechanism(s) for fixed maximum expiratory airflow (max) limitation in patients with chronic persistent asthma. METHODS: When optimally treated and in clinically stable condition, we studied 21 asthmatic patients and classified them into three groups based on the severity of expiratory airflow limitation: (1) group A included 5 asthmatic patients (four women; mean +/- SD age, 51 +/- 17 years) with mild persistent asthma (FEV(1) > 80% predicted) with serial FEV(1) measurements obtained prior to the present study for 16 +/- 4 years; (2) group B included 11 asthmatic patients (three women; mean age, 64 +/- 11 years) with moderate persistent asthma (FEV(1) of 60 to 80% predicted) with serial FEV(1) measurements for 12 +/- 4 years; and (3) group C included 5 asthmatic patients (three women; mean age, 55 +/- 16 years) with severe persistent asthma (FEV(1) < 60% predicted) with serial FEV(1) measurements for 11 plus minus 5 years. RESULTS: Lung CT indicated no or trivial emphysema, and diffusion was normal in all asthmatics. There was a marked loss of lung elastic recoil at total lung capacity (TLC) in all asthmatic patients in group B (16 +/- 4 cm H(2)O) and group C (15 +/- 5 cm H(2)O), but none or minimal in group A (22 +/- 1 cm H(2)O) [p < 0.01], and loss of elastic recoil accounted for 34% and 50% of decreased maximal expiratory airflow (max) at 80% and 70% TLC, respectively. Comparison with previous longitudinal data indicated individual asthmatics when in clinically stable condition remained predominantly in the same FEV(1) percent predicted classification group as in the current study. CONCLUSION: Patients with chronic moderate and severe persistent asthma, despite optimal therapy, have reduced max for many years in part due to (early?) loss of lung elastic recoil from unknown mechanism(s). This challenges current concept of airway remodeling.

Aged↗
PubMed1988

Serial pulmonary function testing in patients with systemic lupus erythematosus.

Previous studies have documented the pulmonary function abnormalities associated with systemic lupus erythematosus (SLE). There are very few data, however, regarding the progression of such changes. To study this question, we evaluated the pulmonary function of a group of 25 patients with SLE from two to seven years after a set of pulmonary function tests had been performed as part of their overall initial assessment. Reductions in diffusing capacity, FVC, and total lung capacity did not change significantly for the group over the period of our study. The mean FEF25-75%, which was initially low, and the mean FEV1/FVC ratio, which was initially normal, both decreased significantly. The observed abnormalities in airway function were not related to smoking history. Other aspects of lupus activity, as measured by serum creatinine levels and clinical activity, did not appear related to progression of lung disease.

Adult↗
PubMed1989

[Volume, flow and respiratory muscle strength in mitral stenosis].

Pulmonary function and respiratory muscle strength was assessed in 20 patients with mitral stenosis uncomplicated by other illness. Pulmonary function was evaluated by spirometry, flow-volume curves, functional residual capacity (FRC) and total lung capacity (TLC). Respiratory muscle strength was evaluated by measurement of maximal static inspiratory and expiratory mouth pressure (PIM, PEM cmH2O) at FRC and TLC respectively. Spirometric, FRC and TLC average values were normal. The maximal expiratory flow rate at 50 and 25% of vital capacity were decreased to 49.5 and 38.3% from predicted values. The values of PIM and PEM in patients (-93 +/- 17; 128 +/- 32 cmH2O, respectively) were similar to those of 12 normal subjects studied at comparable lung volume. Our results were similar to previous reports. There was no evidence of decreased respiratory muscle force, probably because the patients nutritional status and cardiac output were normal.

Adolescent↗
PubMed1983

The role of sympathomimetic amines in the dyspnoea of thyrotoxicosis.

Nine untreated thyrotoxic patients (5 males and 4 females) aged 23 to 56 years who complained of dyspnoea on moderate exertion were studied. Measurements of forced expiratory volume (FEV1), vital capacity (VC) and total lung capacity (TLC), oxygen consumption, (VO2), carbon dioxide output (VCO2) and the minute ventilation (VE) were determined on three occasions: before treatment; after treatment with propranolol and after carbimazole. Dyspnoea disappeared in 4 patients out of 9 after treatment with propranolol, while none were dyspnoeic when they became euthyroid. There was no significant difference in FEV1, VC, TLC and FRC on the three occasions. The differences between the VO2, VCO2 and VE before treatment and these values after treatment with carbimazole were significant. We conclude that the dyspnoea of thyrotoxicosis is due to both the effect of catecholamines and the metabolic effect of thyroxine.

Adult↗
PubMed1979

The effect of smoking cessation on pulmonary function: a 30-month follow-up of two smoking cessation clinics.

To obtain further information about the effects of cessation of smoking on pulmonary function, we followed subjects who attended 2 smoking cessation clinics during a period of 30 months. This paper reports the results from 15 persons who succeeded in stopping smoking for the full 30-month period and from 42 who did not succeed for more than one month. Testing included a respiratory questionnaire, spirometry, and the single-breath N2 test. Standardized methods, the same equipment, and the same experienced personnel were used throughout the study. We found that forced vital capacity, one-second forced expiratory volume, closing volume as a percentage of vital capacity, closing capacity as a percentage of total lung capacity, and the slope of the alveolar plateau of the single-breath N2 test all improved significantly in the subjects who stopped smoking. This improvement continued for as long as 6 to 8 months, and then remained stable. There was no sex difference in the response to smoking cessation, nor could we find a threshold of function below which cessation did not result in improvement. On the contrary, those subjects with the greatest impairment initially showed the greatest improvement. Respiratory symptoms virtually disappeared in those who stopped smoking. Subjects who continued to smoke showed an initial improvement in some function tests, probably due to a marked decrease in consumption, but no significant improvement during the whole period. We concluded from this study that cessation of smoking results in definite improvement in pulmonary function, that there is greater improvement in persons who begin with impaired function than in those whose function is initially normal, that respiratory symptoms disappear rapidly.

Adult↗
PubMed1996

Comparison of methods of measuring static lung volumes.

The measurement of static lung volumes is important for the accurate diagnosis of lung disorders, and when making volume-dependent measurements, such as airways resistance. There are a variety of methods available. The most accurate method is that of constant volume body plethysmography, which provides an estimate of total lung capacity regardless of the presence of airflow obstruction. Whilst this method may overestimate lung volumes in asthmatics, and is technically more demanding than gas dilution methods, this should be regarded as the principal method for estimating lung volumes. Gas dilution estimates of multi-breath helium or nitrogen dilution or single-breath estimates using the same gases all underestimate total lung capacity in the presence of airflow obstruction. Single-breath methods will underestimate volumes to a greater extent than multi-breath methods. Multi-breath helium dilution is currently regarded as the acceptable alternative to body plethysmography. Estimates of lung volumes from chest radiographs provide an estimate of lung volumes independent of airflow obstruction. They are probably prone to greater variability than body plethysmographic estimates, and it is regarded as unacceptable to expose patients to excess radiation. Other methods being developed include estimates from nuclear magnetic imaging and computed tomography.

Humans↗
PubMed1980

Disturbance of respiratory muscle function in patients with mitral valve disease.

A reduced total lung capacity associated with a normal or decreased lung recoil pressure at full inflation (Pel max) has been noted in patients with valvular heart lesions. In order to investigate the mechanism underlying this inappropriately low Pel max, we measured respiratory mechanics in a group of 15 patients with mitral valve disease uncomplicated by other illness. The total lung capacity was 81 percent of control. The static pressure-volume curve of the long intersected the normal one in the vicinity of functional residual capacity (i.e., the recoil pressure was increased at large lung volumes and diminished at low lung volumes), and both expiratory compliance and Pel max were significantly decreased. In 13 of the 15 patients, the minimal (inspiratory) pleural pressure-volume curve was shifted so that the pressures generated by the inspiratory muscles were less negative than normal at any given lung volume. The decrease in Pel max was proportional to the alteration in muscle pressures. These findings indicate (1) that patients with mitral valve disease have compromised function of the inspiratory muscles, and (2) that this alteration is responsible for the low Pel max. Respiratory muscle weakness contributes to the restriction of lung volume in patients with pulmonary vascular congestion and is probably implicated in cardiac dyspnea.

Adolescent↗
PubMed1983

Lung mechanics following aspiration of 0.1 N hydrochloric acid.

Pressure-volume curves were obtained from excised left lungs of goats at 4, 24, and 48 h after tracheal instillation of 2.5 ml/kg of 0.1 N HCl. Air total lung capacity (TLC) at transpulmonary pressure (PL) = 35 cmH2O was 38.8 ml/kg body weight before acid, and was reduced sharply to 21.1 at 4 h, then increased to 25.6 at 24 h and 32.1 at 48 h. Excess extravascular lung water (EVLW) could account for only part of the volume reductions. Specific compliance ratio of transpulmonary pressure to total lung capacity (CL/TLC) between PL of 5 and 0 cmH2O was reduced from 0.074/cmH2O to 0.050, 0.048, and 0.053/cmH2O, respectively. Saline TLC (PL = 10 cmH2O) changed from 44.8 to 32.4, 34.3, and 45.4 ml/kg, respectively, but CL/TLC did not, suggesting airway obstruction. After injury, trapped volume at PL = 0 increased from 24.9 to 29.2, 43.3, and 37.3% TLC with air, and from 20.3 to 38.5, 33.1, and 28.5%, respectively, with saline. Air volume at a PL = 10 cmH2O on deflation fell from 82.0 to 72.1% TLC at 4 h, but was near control at 24 and 48 h. The reduction in ventilated volume was not reflected in proportionately increased shunt; therefore, some compensatory vasoconstriction must have occurred. We suggest that in affected regions increased surface forces, increased EVLW, and airway obstruction caused reductions of lung volume.

Animals↗
PubMed2003

Lung volume effects on pharyngeal swallowing physiology.

The experiment was a prospective, repeated-measures design intended to determine how the variation of lung volume affects specific measures of swallowing physiology. Swallows were recorded in 28 healthy subjects, who ranged in age from 21 to 40 yr (mean age of 29 yr), by using simultaneous videofluoroscopy, bipolar intramuscular electromyography, and respiratory inductance plethysmography. Each subject swallowed three standardized pudding-like consistency boluses at three randomized lung volumes: total lung capacity, functional residual capacity, and residual volume. The results showed that pharyngeal activity duration of deglutition for swallows produced at residual volume was significantly longer than those occurring at total lung capacity or at functional residual capacity. No significant differences were found for bolus transit time or intramuscular electromyography of the superior constrictor. The results of this experiment lend support to the hypothesis that the respiratory system may have a regulatory function related to swallowing and that positive subglottic air pressure may be important for swallowing integrity. Eventually, new treatment paradigms for oropharyngeal dysphagia that are based on respiratory physiology may be developed.

Adult↗
PubMed2006

Medical and psychologic outcome of living lobar lung transplant donors.

BACKGROUND: Living donor lobar lung transplantation is a viable therapy for carefully selected patients with end-stage pulmonary disease. Its success is largely dependent upon donor outcome, including both physical and emotional factors. To date, there has been little focus on psychosocial outcomes of lobar lung donors. METHODS: Retrospective evaluation of 15 of 20 living lobar lung transplant donors was performed. Donors underwent evaluation of pulmonary function after recovery from donor lobectomy. Participants completed two self-report questionnaires, the SF-36 Health Survey (SF-36) and the Beck Depression Inventory (BDI), as well as an open-ended psychiatric interview. RESULTS: After lobar donation, mean forced expiratory volume in 1 second (FEV(1)) decreased by 21 +/- 2%, forced vital capacity (FVC) decreased by 16 +/- 3%, total lung capacity (TLC) decreased by 15 +/- 3%, and single-breath diffusing capacity (DLCO) decreased by 14 +/- 4%. All subjects scored higher than the national average on both the physical and mental health components of the SF-36. The BDI scores showed no evidence of clinical depression. However, the subjective interviews elicited two common complaints: (1) a decline in exercise performance, not accounted for by resting lung function measurements; and (2) a dissatisfaction with the degree of acknowledgment of their donation. CONCLUSIONS: Living lobar lung transplant donors enjoy generally satisfactory physical and emotional health. Donors report positive feelings about donation, but wish to be recognized and valued by the transplant team and by the recipient. Despite preservation of lung function within the normal range, some donors also experience a subjective decline in exercise tolerance. Long-term medical and psychologic follow-up appears warranted to monitor symptoms of exercise impairment and to enhance the donor experience.

Forced Expiratory Volume↗
PubMed1994

Pulmonary functions in congenital scoliosis.

STUDY DESIGN: Thirty-six patients with congenital scoliosis underwent full clinical and radiologic evaluation of their deformity and their full pulmonary functions. OBJECTIVES: This study observed pulmonary functions in congenital scoliosis in detail, evaluated pulmonary functions in nonsurgically treated patients, and established whether, in surgically treated patients, there are any differences between those with multiple thoracic anomalies and those with lumbar or one of two thoracic anomalies. SUMMARY OF BACKGROUND DATA: Eighty-six of our patients in both groups (surgically and nonsurgically treated) showed abnormal increases in residual volumes, indicating a restrictive pattern of lung function. The results of their pulmonary functions were analyzed using predicted values to eliminate age affect. METHODS: Pulmonary functions were assessed using the Gould 5000IV Computerized Pulmonary Function System. RESULTS: Overall, mean total lung capacity was 89% of predicted value, and mean vital capacity and forced vital capacity were 74% of predicted value. The mean residual volume was significantly increased, being 154% of predicted value. Nonsurgically treated patients showed normal total lung capacity (mean 99.8% of predicted value); this mean value was 82% of predicted value in surgically treated patients. CONCLUSION: Vital capacity was found to be significantly reduced in surgically treated patients (68% of predicted value), especially in those patients who had multiple thoracic anomalies. We believe that children with congenital scoliosis due to multiple anomalies should be operated on at an early age before deformity is too severe.

Adolescent↗
PubMed1983

Bronchiolitis obliterans. Report of three cases with detailed physiologic studies.

We describe three patients with bronchiolitis obliterans seen at our hospital during the last two years. Their ages were 25, 49 and 69 years. One developed the disease secondary to a probable viral infection, another inhaled fumes, and the third was exposed to unknown precipitating factors. Lung biopsy showed changes compatible with bronchiolitis obliterans in the first two, while in the third, changes were compatible with bronchiolitis obliterans and interstitial pneumonitis. Pulmonary function tests of patient 1 showed severe airflow limitation, increased total lung capacity, a shift of the pressure-volume curve upward with a normal slope, and an elevation of upstream resistance. In patient 3 (bronchiolitis obliterans with interstitial pneumonitis) total lung capacity was normal, the pressure volume curve was shifted slightly to the right and upstream resistance was increased. After treatment with steroids, clinical improvement was observed along with normalization of the pressure-volume curve and a decline in the upstream resistance.

Adult↗
PubMed1989

Scintigraphic regional lung dimensions in upright and head-down men.

Our purpose was to analyze regional intrapulmonary volumes and dimensions (especially heights) between total lung capacity and residual volume in upright and head-down healthy men. This analysis was based on the combination of previously obtained scintigraphic data of regional alveolar expansions and of lung shape. This analysis demonstrated that the changes in height were markedly smaller for the apical zones than for the diaphragmatic zones, especially in upright posture but to a smaller extent in head-down posture also. These changes in height in upright posture were attributable to the additive effects of changes in lung shape (which favored larger height changes in the more diaphragmatic zones) and the effects of the changes in regional alveolar expansion (which caused larger volume changes in the diaphragmatic zones). In head-down posture the effects of changes in lung shape (which again favored larger height changes in the diaphragmatic zones except at high volumes) were only partially counteracted by the now inverted changes in alveolar expansion. These height changes were qualitatively in agreement with the cephalad displacement of the minor fissure during lung inflation from residual volume to total lung capacity in both postures, measured previously on chest X-rays. In conclusion, this study shows that the gravitational distributions of alveolar expansion, as assessed by scintigraphy, go along with more complex shape-dependent distributions of regional dimensions and volumes as assessed, e.g., by radiological techniques.

Adult↗
PubMed1994

Scanning electronmicroscopic morphometry of emphysema in humans.

We quantitated the holes in alveolar walls in 11 nonemphysematous lungs and in 11 lungs with mild emphysema, all of which were removed at surgery. We found that in the nonemphysematous lungs, 94.1% of the holes were smaller than 10 microns in diameter and only 0.2% were larger than 20 microns. In the lung parenchyma distant from emphysema, both the maximum diameter of the holes and the diameter of alveoli increased. In the parenchyma between emphysema, the areas of alveolar walls represented by holes also increased, as did the average hole area and number of holes per alveolus. We found that alveolar holes in the regions between emphysema correlated better with pulmonary function tests than did those in regions distant from emphysema. The maximum diameter of holes and the number of holes per alveolus correlated with functional residual capacity, residual volume, closing capacity expressed as a proportion of total lung capacity (CC/TLC), and static recoil pressure of the lung at TLC. Emphysema correlated with CC/TLC and with the transpulmonary pressure at 90% TLC. Bronchiolar lesions were not related to pulmonary function tests. Our data provide support for the hypothesis that the tissue surrounding emphysematous lesions contributes to loss of recoil.

Functional Residual Capacity↗
PubMed1985

Effects of acute pleural effusion on respiratory system mechanics in dogs.

We determined regional (Vr) and overall lung volumes in six head-up anesthetized dogs before and after the stepwise introduction of saline into the right pleural space. Functional residual capacity (FRC), as determined by He dilution, and total lung capacity (TLC) decreased by one-third and chest wall volume increased by two-thirds the saline volume added. Pressure-volume curves showed an apparent increase in lung elastic recoil and a decrease in chest wall elastic recoil with added saline, but the validity of esophageal pressure measurements in these head-up dogs is questionable. Vr was determined from the positions of intraparenchymal markers. Lower lobe TLC and FRC decreased with added saline. The decrease in upper lobe volume was less than that of lower lobe volume at FRC and was minimal at TLC. Saline increased the normal Vr gradient at FRC and created a gradient at TLC. During deflation from TLC to FRC before saline was added, the decrease in lung volume was accompanied by a shape change of the lung, with greatest distortion in the transverse (ribs to mediastinum) direction. After saline additions, deflation was associated with deformation of the lung in the cephalocaudal and transverse directions. The deformation with saline may be a result of upward displacement of the lungs into a smaller cross-sectional area of the thoracic cavity.

Animals↗
PubMed1975

Effect of intrathoracic pressure on pressure-volume characteristics of the lung in man.

Quasi-static pressure-volume (P-V) curves in normal seated human subjects were determined with pressure at the airway opening (Pa0) set below (negative pressure), above (positive pressure), or equal to ambient pressure. Dynamic compliance (Cdyn) during controlled continuous negative pressure breathing (CNPB) was also studied. Quasi-static P-V curves at negative pressure were decreased in slope, reflected a decrease in total lung capacity, and intersected the P-V curve obtained at ambient Pa0. At positive pressure the P-V curves showed an increase in slope and an increase in total lung capacity. During CNPB a fall in Cdyn was found. The fall in Cdyn was rapid and persisted for the duration of CNPB. Cdyn promptly returned to control levels when Pa0 was adjusted to ambient pressure.

Adult↗
PubMed1992

Single-breath, room-air method for measuring closing volume (phase 4) in the normal human lung.

The purpose of this study was to evaluate a new method to measure closing volume (CV). This new method does not require oxygen or inert gases to be inhaled to obtain the onset of phase 4. Because there are regional differences in the concentrations of the resident alveolar gases (O2, CO2, and N2), there should be an abrupt change in the concentration of these gases at the terminal portion of a prolonged expired vital capacity (VC) that marks the onset of phase 4. Nine normal healthy subjects, 30 to 65 years of age, inspired room air from residual volume (to mimic the maneuver of the standard single breath N2 (SBN2) washout test) to total lung capacity. During the expiration (flow constant at 250 ml.s-1) following a 10-s breath hold at total lung capacity, the exhaled gas was analyzed with a mass spectrometer for fractions of O2, CO2, and N2. Although the onset of phase 4 can be shown as the change in concentration of any of the three alveolar resident gases, oxygen was selected because (1) it demonstrates a greater apex to base concentration gradient than that found with CO2 and N2, and (2) a clear identification of the onset of phase 4 (minimum value of O2 fraction). With this method, the mean +/- SEM of CV was 16.8 +/- 1.52 percent (CV x 100/VC). No significant difference was found among the room air method, SBN2 method, and the helium bolus technique.

Adult↗