Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Total Lung Capacity”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 523 records · Page 29Linked to original sources
PubMed1999

A preliminary study of long-term treatment with interferon gamma-1b and low-dose prednisolone in patients with idiopathic pulmonary fibrosis.

BACKGROUND AND METHODS: Patients with idiopathic pulmonary fibrosis have progressive scarring of the lung and usually die within four to five years after symptoms develop. Treatment with oral glucocorticoids is often ineffective. We conducted an open, randomized trial of treatment with a combination of interferon gamma-1b, which has antifibrotic properties, and an oral glucocorticoid. We studied 18 patients with idiopathic pulmonary fibrosis who had not had responses to glucocorticoids or other immunosuppressive agents. Nine patients were treated for 12 months with oral prednisolone alone (7.5 mg daily, which could be increased to 25 to 50 mg daily), and nine with a combination of 200 microg of interferon gamma-1b (given three times per week subcutaneously) and 7.5 mg of prednisolone (given once a day). RESULTS: All the patients completed the study. Lung function deteriorated in all nine patients in the group given prednisolone alone: total lung capacity decreased from a mean (+/-SD) of 66+/-8 percent of the predicted value at base line to 62+/-6 percent at 12 months. In contrast, in the group receiving interferon gamma-1b plus prednisolone, total lung capacity increased (from 70+/-6 percent of the predicted value at base line to 79+/-12 percent at 12 months, P<0.001 for the difference between the groups). In the group that received interferon gamma-1b plus prednisolone, the partial pressure of arterial oxygen at rest increased from 65+/-9 mm Hg at base line to 76+/-8 mm Hg at 12 months, whereas in the group that received prednisolone alone it decreased from 65+/-6 to 62+/-4 mm Hg (P<0.001 for the difference in the change from baseline values between the two groups); on maximal exertion, the value increased from 55+/-6 to 65+/-8 mm Hg in the group that received combined treatment and decreased from 55+/-6 mm Hg to 52+/-5 mm Hg in the group given prednisolone alone (P<0.001). The side effects of interferon gamma-1b, such as fever, chills, and muscle pain, subsided within the first 9 to 12 weeks. CONCLUSIONS: In a preliminary study, 12 months of treatment with interferon gamma-1b plus prednisolone was associated with substantial improvements in the condition of patients with idiopathic pulmonary fibrosis who had had no response to glucocorticoids.

Carrier Proteins↗
PubMed1994

Surgical treatment of bullous emphysema: experience with the Brompton technique.

The technique first described by Monaldi has been modified for the treatment of discrete emphysematous bullae. Fifty-eight patients (median age, 56 years) underwent this procedure between 1983 and 1992. The operative mortality was 6.9% (4 patients). Fifty-two patients (89.6%) noted symptomatic improvement, as measured using the modified Medical Research Council of Great Britain dyspnea scale, from a mean value of 3.7 preoperatively to 2.1 postoperatively. Two patients remained unchanged symptomatically. In all patients, amelioration of symptoms was accompanied by an objective improvement in lung function. A mean increase of 28% was noted in the forced expiratory volume in 1 second (p < 0.05), and a 12.3% improvement in the total lung capacity was observed (p < 0.002). The residual lung volume-total lung capacity ratio declined from a mean of 70% to 57% after operation. A forced expiratory volume in 1 second of less than 500 mL (p < 0.05) and carbon dioxide tension of greater than 6.5 kPa (p < 0.05) were significant predictors of poor prognosis. The median follow-up period has been 1.9 years (range, 0.5 to 9 years). Two patients have returned for further drainage of new bullae on the operated side, and this was carried out percutaneously in both. We conclude that this technique offers a simple, safe, and effective method for the treatment of discrete bullous disease in patients with emphysema.

Aged↗
PubMed2003

Peak expiratory flow in children and adolescents with idiopathic scoliosis.

Spirometric and plethysmographic examinations were performed in two groups of children with idiopathic scoliosis and healthy children. Group I, 23--children with scoliosis 1 degree by Cobb, spinal curvature 17.2 degree, 12 girls and 11 boys at the age 8-15 years (the mean age was 11.4 +/- 2.4 yr). In Group II were 35 children, 28 girls and 7 boys at the age 12-19 years (the mean age was 14.67 +/- 1.47 yr) with mean angle of curvature 63.35 degree, which is grade II and III scoliosis according to Cobb. The Control Group were 20 children, 13 girls and 7 boys at the age of 8-16 years (the mean age was 13.77 +/- 1.72 yr). The measurements were done using Body--plethysmography with pneumotachograph Jaeger. All subjects had respiratory function examination performed, which included: total lung capacity (TLC), forced vital capacity (FVC), forced expiratory volume in 1 sec. (FEV1), residual volume (RV) and intrathoracic gas volume (ITGV). At the same time peak expiratory flow--PEF were determined. In children with scoliosis at initial stage, Group I, were found slightly decreased total lung capacity--TLC and statistically significantly decreased intrathoracic gas volume--ITGV as well as residual volume--RV in comparison to the control group. Forced vital capacity--FVC and forced expiratory volume in 1 sec.--FEV1 were normal. But statistically significantly decreased PEF values were found in comparison to the control group (p < 0.05). It means that restrictive and obstructive disturbances of lungs progressing in grade II and III scoliosis were shown manifested by reduced values of TLC, FVC, ITGV and RV. A statistically significant decrease of peak expiratory flow together with the growth of spinal curvature angle was shown in grade II and III scoliosis in comparison with both the control group and the studied Group I (p < 0.001, p < 0.05).

Adolescent↗
PubMed1994

Effect of three different surgical prone positions on lung volumes in healthy volunteers.

Ten healthy volunteers were placed in three different surgical prone positions (knee-chest, Eschmann frame and two supports, one each for the thorax and pelvis); the normal prone position without any supports was used as a control. Lung volumes using helium dilution and spirometry were calculated for each volunteer in each position. Compared with the control position, functional residual capacity, expiratory reserve volume, residual volume and total lung capacity were significantly higher in the knee-chest position. Functional residual capacity and expiratory reserve volume were significantly higher in the frame position. No advantage was gained with the use of the two supports position. We conclude that, of these three prone positions in awake volunteers, the knee-chest position causes least respiratory restriction.

Adult↗
PubMedDate not supplied

Fibrosing alveolitis in childhood. A long-term follow-up.

A retrospective analysis of 14 pediatric cases with fibrosing alveolitis, proved by lung biopsy, was carried out. The children were initially 6-16 years old (mean: 9.8 years) and were observed for 2 to 7 years. Symptoms had been present prior to diagnosis for 1 to 156 weeks (median: 11 weeks). The most prominent clinical findings were dyspnoea (100%), dry cough (91%), tachypnoea (85%), and weight loss (70%). Open (n = 9) or transbronchial (n = 5) lung biopsy specimens had predominantly cellular appearances in 8 children (group A) and showed predominantly fibrotic changes in 6 cases (group B). Lung function tests revealed a marked ventilatory impairment in all children. Mean vital capacity was 44% (SD 16%), and total lung capacity 58% (SD 14%) of the predicted normal values. Specific lung compliance was significantly lower in children with fibrotic changes (mean: 0.016 vs. 0.030 ml/cmH2O/ml in patients of group A, p less than 0.05). Results from 200 lung function measurements were evaluated during the follow-up. Corticosteroid treatment improved vital capacity in all children after 6 and 12 months of treatment to 64% and 62% of the predicted normal, respectively. Deterioration of pulmonary function was observed in 7 children when prednisone was tapered to below 10 mg per day. Only 4 children had a normal vital capacity at their last visit to the clinic. We conclude that children with fibrosing alveolitis experience severe alterations in lung function, and that the overall outlook is quite unfavorable.

Adolescent↗
PubMed1999

A pilot study of expiratory flow limitation and lung volume reduction surgery.

STUDY OBJECTIVES: To examine the relationships between changes in expiratory flow limitation (FL) during anesthesia and postoperative responses to lung volume reduction surgery (LVRS). DESIGN: Prospective consecutive case comparison. SETTING: University medical center. PATIENTS: Eight patients with severe emphysema. INTERVENTIONS: General anesthesia with muscle paralysis and thoracic epidural analgesia were provided for LVRS via median sternotomy. MEASUREMENTS: FEV(1), functional residual capacity (FRC), and total lung capacity (TLC) were measured preoperatively and 3 months postoperatively. Tidal volume (VT) flow/volume (F/V) curves were obtained with a Pitot-type spirometer. VT, expiratory flow rate at 0. 25 x VT (V'VT,25% ), and peak expiratory flow rate (V'VT,MAX) were obtained from VT F/V curves to derive V'VT,25%/V'VT,MAX ratio as a measure of FL. RESULTS: Closed chest VT F/V curves during anesthesia pre-LVRS showed four patients with FL (group A) whose V'VT,25%/V'VT, MAX ratio was 0.38 +/- 0.06 (mean +/- SD) and four patients without FL (group B) whose V'VT,25%/V'VT,MAX ratio was 0.82 +/- 0.06 (p = 0. 0001). Closed chest post-LVRS V'VT,25%/V'VT,MAX ratio during anesthesia increased by 0.48 +/- 0.08 in group A, compared with a 0. 19 +/- 0.16 reduction in group B (p = 0.0001). Preoperative FEV(1) was 0.57 +/- 0.10 L for group A vs 0.82 +/- 0.13 L for group B (p = 0.02). Postoperative FEV(1) increased by 67 +/- 40% for group A (p = 0.03) vs 29 +/- 21% for group B (not significant). FRC decreased by 33 +/- 3% for group A vs 17 +/- 5% for group B (p = 0.0007), and FRC/TLC decreased by 0.14 +/- 0.05 for group A vs 0.01 +/- 0.07 for group B (p = 0.026). Post-LVRS V'VT,25%/V'VT,MAX ratio change during anesthesia correlated with postoperative reduction in FRC (r(2) = 0. 89, p = 0.0004) and FRC/TLC (r(2) = 0.52, p = 0.045). CONCLUSION: Post-LVRS change in V'VT,25%/V'VT,MAX ratio during anesthesia showed a linear relationship with 3-month postoperative improvement in dynamic hyperinflation. Thus, V'VT,25%/V'VT,MAX ratio may help provide valuable insights into the interactions between chest wall recoil, dynamic hyperinflation, and VT flow rates in patients with severe COPD and LVRS.

Aged↗
PubMed1995

Large lungs and growth hormone: an increased alveolar number?

Previous physiological studies suggest that increased lung growth in patients with acromegaly is associated with either a normal or above normal pulmonary transfer factor. These findings can be interpreted to suggest either alveolar hypertrophy or hyperplasia as the mechanism for lung growth in this condition. Since the ventilated airspaces retain normal elastic properties, we wanted to determine whether the mechanism for lung growth in acromegaly is the result of an increased alveolar number rather than size. Measurements of pulmonary distensibility (K) (an index of alveolar size), elastic recoil, single-breath carbon monoxide transfer factor and carbon monoxide transfer coefficient (KCO), pulmonary capillary blood volume and alveolar membrane diffusing capacity, together with chest width, were compared in nonsmoking, acromegalic and normal men and women, with and without an increased lung size. Pulmonary transfer factor was normal for all groups studied, regardless of lung size. However, KCO was inversely related to total lung capacity (% predicted) for all subjects and KCO (% predicted) was inversely related to chest width in men. Pulmonary capillary blood volume (% predicted) was inversely related to total lung capacity (% predicted) for subjects with large lungs. Pulmonary distensibility (K), membrane diffusing capacity and elastic recoil were within the normal range. These findings suggest normal alveolar size, alveolar membrane surface area and mechanical function in subjects with large lungs. They also suggest that KCO may not be a reliable guide to the interpretation of the mechanism of lung growth in individuals with disproportionately large lungs, and may be reduced because not all the alveoli are perfused. The normal values for pulmonary distensibility found in all our individuals with large lungs, including acromegalics, suggest that lung growth has been achieved by an increased alveolar number rather than size. However, morphometric studies of the lungs of nonsmoking, acromegalic subjects without lung disease, are required to substantiate this finding.

Acromegaly↗
PubMed1989

Effect of bracing on respiratory mechanics in mild idiopathic scoliosis.

The use of a corrective orthopaedic brace is an established form of management for patients with progressive idiopathic scoliosis. Thirteen patients with mild idiopathic scoliosis were studied with and without the corrective brace applied. Lung volumes and the pattern of chest wall and abdominal movement were measured during quiet breathing. Transdiaphragmatic pressures were measured in six of the patients and upper ribcage movement in seven patients. Application of the brace resulted in a significant reduction in vital capacity (14%), functional residual capacity (22%), and total lung capacity (12%). There was no effect on respiratory rate or minute volume. In the erect position the pattern of chest wall movement was altered with a reduction in lower ribcage movement of 46% and abdominal wall of 39% and an increase in upper ribcage movement of 43%. These changes were greater in the supine position. There was at least a twofold increase in end inspiratory and end expiratory gastric pressures during tidal breathing, but oesophageal pressures were not affected by the brace. Transdiaphragmatic pressures showed a similar twofold increase, which implies a substantial increase in the work of breathing. In view of the doubts concerning the influence of bracing on the natural history of idiopathic scoliosis and the substantial functional effect of bracing on the respiratory system, it is suggested that the current practice of bracing in this condition needs to be reviewed.

Adolescent↗
PubMed1994

The effect of aminophylline on the force-length characteristics of the diaphragm.

The aim of our study was to evaluate the effect of aminophylline on the contractile function of the human diaphragm during varying muscle fiber length. Ten healthy subjects were studied during maximal sniff maneuvers and bilateral phrenic nerve twitch stimulations, with and without intravenous infusion of aminophylline in a randomized fashion. The transdiaphragmatic pressures generated at various baseline lung volumes, from residual volume to 90% of total lung capacity, were recorded before and after the induction of diaphragm exhaustion. At all levels of lung volume, aminophylline did not have an effect on the contractility of the fresh diaphragm. In the exhausted diaphragm, however, the pressure values, induced by sniffs and twitch stimulations, were significantly improved by aminophylline. This positive effect on diaphragm contractility was also impressive at 60, 75, and 90% of total lung capacity. This indicates that aminophylline significantly improves the contractile function of the exhausted human diaphragm, even if the muscle fibers are shorter than optimal. This effect occurs regardless of the neuronal firing rate, whether it is low (twitch stimulation) or high (sniff maneuver).

Adult↗
PubMed2000

Size distribution of recruited alveolar volumes in airway reopening.

In 11 isolated dog lung lobes, we studied the size distribution of recruited alveolar volumes that become available for gas exchange during inflation from the collapsed state. Three catheters were wedged into 2-mm-diameter airways at total lung capacity. Small-amplitude pseudorandom pressure oscillations between 1 and 47 Hz were led into the catheters, and the input impedances of the regions subtended by the catheters were continuously recorded using a wave tube technique during inflation from -5 cm H(2)O transpulmonary pressure to total lung capacity. The impedance data were fit with a model to obtain regional tissue elastance (Eti) as a function of inflation. First, Eti was high and decreased in discrete jumps as more groups of alveoli were recruited. By assuming that the number of opened alveoli is inversely proportional to Eti, we calculated from the jumps in Eti the distribution of the discrete increments in the number of opened alveoli. This distribution was in good agreement with model simulations in which airways open in cascade or avalanches. Implications for mechanical ventilation may be found in these results.

Animals↗
PubMed1993

Restrictive lung function and asbestos-induced pleural fibrosis. A quantitative approach.

To assess further the clinical significance of asbestos-induced pleural fibrosis, we used a computer algorithm to reconstruct images three dimensionally from the high-resolution computerized tomography (HRCT) scan of the chest in 60 asbestos-exposed subjects. Pulmonary function tests, chest radiographs, and HRCT scans were performed on all study subjects. The volume of asbestos-induced pleural fibrosis was computed from the three-dimensional reconstruction of the HRCT scan. Among those with pleural fibrosis identified on the HRCT scan (n = 29), the volume of the pleural lesion varied from 0.01% (0.5 ml) and 7.11% (260.4 ml) of the total chest cavity. To investigate the relationship between asbestos-induced pleural fibrosis and restrictive lung function, we compared the computer-derived estimate of pleural fibrosis to the total lung capacity and found that these measures were inversely related (r = -0.40; P = 0.002). After controlling for age, height, pack-years of cigarette smoking, and the presence of interstitial fibrosis on the chest radiograph, the volume of pleural fibrosis identified on the three-dimensional reconstructed image from the HRCT scan was inversely associated with the total lung capacity (P = 0.03) and independently accounted for 9.5% of the variance of this measure of lung volume. These findings further extend the scientific data supporting an independent association between pleural fibrosis and restrictive lung function.

Aged↗
PubMed1984

Pulmonary functions of rats trained with mild exercise.

The purpose of the present study was to determine if lung function is modified by physical exercise in male and female rats. The animals were subjected to a running program for 5 weeks. At the termination of the program period, the running rats (R) had body weight smaller than the sedentary control rats (S). In male rats, the weights of lung, heart and adrenal glands, which were corrected with body weight, were larger in the R than in the S, and the absolute weight of adrenal glands also increased in the R. The rates of peak flow and maximum expiratory flow at 50% total lung capacity, which were corrected with either body weight, lung weight or total lung capacity, increased in the R. Because of no significant change in the flow resistance and compliance of the lungs, the increases in the rates of these expiratory flows might have been due to increased airway rigidity caused by some mechanisms relating to exercise stimuli. In female rats, on the other hand, the above changes in the R were little or less.

Animals↗
PubMed2005

[Effect of lung transplantation on pulmonary function in 5 patients with chronic obstructive pulmonary disease].

OBJECTIVE: To investigate the therapeutic effect of lung transplantation on pathophysiology and pulmonary function in chronic obstructive pulmonary disease (COPD) patients. METHODS: Five male COPD (grade IV) patients, aged 51 to 63 yr, were enrolled in the study. The patients underwent pulmonary function tests and the following measurements 2 weeks before and 2 months after the operation. The measured parameters included forced vital capacity (FVC), forced expiratory volume in one second (FEV(1)), FEV(1)/FVC, maximal ventilatory volume (MVV), residual volume (RV), total lung capacity (TLC), RV/TLC, inspiratory capacity (IC), thoracic gas volume (TGV), peak expiratory flow (PEF), total airway resistance (R(aw)total), diffusion capacity for CO of lung (D(L)CO), diffusion capacity for CO of lung/alveolar volume (D(L)CO/V(A)), 6 minute walk distance (6MWD), partial pressure of oxygen in arterial blood (PaO(2)), alveolar-artery oxygen gradient [P((A-a))O(2)], oxygen saturation in arterial blood (SaO(2)), partial pressure of carbon dioxide in arterial blood (PaCO(2)) and mean pulmonary arterial pressure (mPAP). RESULTS: The measured parameters before vs after the operation were as follows: MVV (23.6 +/- 5.8) vs (71.6 +/- 21.8) L, FEV(1) (0.68 +/- 0.21) vs (1.85 +/- 0.46) L, FEV(1)/FVC (37.4 +/- 8.3)% vs (75.6 +/- 13.9)%, PaO(2) (60.0 +/- 9.1) vs (86.2 +/- 2.9) mm Hg (1 mm Hg = 0.133 kPa), SaO(2) (90.0 +/- 4.6)% vs (96.8 +/- 0.5)% and mPAP (31.2 +/- 5.5) vs (16.6 +/- 1.8) mm Hg; all were significantly improved in the 5 cases (all P < 0.05); IC [(1.16 +/- 0.26) vs (1.83 +/- 0.35) L], TGV [(6.52 +/- 0.27) vs (4.52 +/- 0.29) L], RV [(5.12 +/- 0.39) vs (3.20 +/- 0.32) L], RV/TLC [(71.0 +/- 5.6)% vs (51.3 +/- 2.5)%] and R(aw) total [(6.62 +/- 0.99) vs (2.48 +/- 0.87) cm H2O.L(-1).s(-1)] were significantly improved in 3 of the 5 patients (all P < 0.05); PEF [(1.65 +/- 0.40) vs (3.92 +/- 1.63) L/s], D(L)CO [(8.5 +/- 3.0) vs (21.0 +/- 6.2) ml.min(-1).mm Hg(-1)] and 6MWD [(46.8 +/- 14.7) vs (246.8 +/- 51.9) m] were significantly increased in 4 of the 5 patients (all P < 0.05). FVC [(1.85 +/- 0.40) vs (2.45 +/- 0.49) L], TLC [(7.19 +/- 0.15) vs (6.26 +/- 0.73) L], D(L)CO/V(A) [(2.90 +/- 1.50) vs (5.41 +/- 0.87) L.min(-1).mm Hg(-1)], P((A-a))O(2) [(37.6 +/- 16.3) vs (17.8 +/- 6.3) mm Hg] and PaCO(2) [(44.6 +/- 7.7) vs (37.4 +/- 3.4) mm Hg] were also improved but did not reach significance (all P > 0.05). CONCLUSION: Spirometry, airway resistance, residual capacity, diffusion capacity, exercise tolerance and gas exchange were improved remarkably after lung transplantation in COPD patients.

Forced Expiratory Volume↗
PubMed2004

Asbestos-related pleural disease due to tremolite associated with progressive loss of lung function: serial observations in 123 miners, family members, and residents of Libby, Montana.

BACKGROUND: The community of Libby, Montana has recently been the focus of national attention secondary to widespread amphibole contamination associated with vermiculite mining and processing. METHODS: Patients who had occupational and non-occupational exposure to amphibole asbestos in Libby, Montana were evaluated for progressive loss of pulmonary function. RESULTS: Of the 123 patients evaluated, 94 demonstrated average age-corrected accelerated loss per year of vital capacity at 3.2%, total lung capacity (TLC) 2.3%, and DLCO 3.3%. All patients all had predominantly pleural changes with minimal to no interstitial disease. CONCLUSIONS: The study demonstrates a progressive loss of pulmonary function in patients exposed to tremolite asbestos.

Aged↗
PubMed1998

Resistive inspiratory muscle training in subjects with chronic cervical spinal cord injury.

OBJECTIVE: To determine whether pulmonary function, respiratory muscle strength, and dyspnea can be improved in individuals with chronic cervical spinal cord injury (SCI). STUDY DESIGN: Ten subjects participated in an 8-week resistive inspiratory muscle training (IMT) program for 15 minutes twice daily. Spirometry, lung volumes, maximum inspiratory pressure (MIP), maximum expiratory pressure (MEP), and dyspnea were measured at baseline, week 4, and week 8. Six months after the study, spirometry, MIP, and MEP were re-measured in a subgroup of the original participants. RESULTS: We found that regular IMT in subjects with cervical SCI significantly improved forced vital capacity (means +/- SE) (11% +/- 2.82% increase), forced inspiratory vital capacity (21% +/- 6.91%), vital capacity (8% +/- 4.36%), total lung capacity (12% +/- 3.23%), functional residual capacity (15% +/- 5.96%), and MIP (24% +/- 6.98%) (p < .05). Furthermore, although no statistical differences were observed for the dyspnea scale, the fact that subjects reported decreased levels (43% +/- 21.30% reduction) of perceived difficulty breathing may be of greater importance. No significant differences from baseline values were found in the seven subjects whose spirometry and respiratory muscle strength were measured 6 months after the study. CONCLUSIONS: Our findings suggest that in individuals with cervical SCI regular resistive IMT may result in decreased restrictive ventilatory impairment and reported dyspnea and, thus, reduced incidence of chronic respiratory complaints, respiratory infection, and other pulmonary complications.

Adult↗
PubMed1993

Effect of priming dose of vecuronium on lung function in elderly patients.

We questioned whether the side effects outweighed the advantages of priming doses of nondepolarizing neuromuscular relaxants in awake patients. We have assessed lung function and clinical evidence of muscle weakness in 10 elderly patients, eight women and two men, aged 67-78 yr, ASA grade I or II, before and 3 min after a priming dose (0.01 mg/kg) of vecuronium. Forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1), maximum midexpiratory flow rate (MMEF), peak expiratory flow rate (PEFR), inspiratory capacity (IC), functional residual capacity (FRC), expiratory reserve volume (ERV), residual volume (RV), slow vital capacity (SVC), and total lung capacity (TLC) were measured by using a Morgan transfer test machine and oxygen saturation (SpO2) was measured by pulse oximetry. All the patients developed ptosis, six had diplopia and were unable to perform the Valsalva maneuver for 10s, and four were unable to swallow or lift their head for > 4s, demonstrating significant muscle weakness. Significant reductions occurred in FVC, FEV1, FRC, ERV, SVC, and TLC. SpO2 decreased in 8 of 10 patients, and in 4 the decrease exceeded 4%. We conclude that priming with vecuronium 0.01 mg/kg in elderly patients causes significant impairment of lung function and a significant decrease in oxygen saturation.

Aged↗
PubMed1998

Voluntary activation of the human diaphragm in health and disease.

Intersubject comparison of the crural diaphragm electromyogram, as measured by an esophageal electrode, requires a reliable means for normalizing the signal. The present study set out 1) to evaluate which voluntary respiratory maneuvers provide high and reproducible diaphragm electromyogram root-mean-square (RMS) values and 2) to determine the relative diaphragm activation and mechanical and ventilatory outputs during breathing at rest in healthy subjects (n = 5), in patients with severe chronic obstructive pulmonary disease (COPD, n = 5), and in restrictive patients with prior polio infection (PPI, n = 6). In all groups, mean voluntary maximal RMS values were higher during inspiration to total lung capacity than during sniff inhalation through the nose (P = 0.035, ANOVA). The RMS (percentage of voluntary maximal RMS) during quiet breathing was 8% in healthy subjects, 43% in COPD patients, and 45% in PPI patients. Despite the large difference in relative RMS (P = 0.012), there were no differences in mean transdiaphragmatic pressure (P = 0.977) and tidal volumes (P = 0.426). We conclude that voluntary maximal RMS is reliably obtained during an inspiration to total lung capacity but a sniff inhalation could be a useful complementary maneuver. Severe COPD and PPI patients breathing at rest are characterized by increased diaphragm activation with no change in diaphragm pressure generation.

Adult↗
PubMed1991

Provocation tests in extrinsic allergic alveolitis in mushroom workers.

The clinical diagnosis of extrinsic allergic alveolitis can be supported by a positive provocation test. Twenty-eight common mushroom (Agaricus bisporus) workers, 4 oyster mushroom (Pleurotus ostreatus) workers and 6 Shii Take mushroom (Lentinus edodes) workers, whose medical history indicated a possible extrinsic allergic alveolitis, were examined. The provocation test consisted of a control day, an exposure day, and half a day of follow-up observation. On the control and exposure days, the body temperature, leucocyte count and lung function were measured every 2 h. The chest X-ray and arterial blood gas sample were taken once. The exposure consisted of a 1-h presence on the common mushroom farm in spawning conditions or inhaling a suspension of spores of Pleurotus or Shii-Take in the laboratory. Eighteen of the 28 people employed on the common mushroom farm, all 4 Pleurotus workers and 4 of the 6 Shii-Take workers were diagnosed as having extrinsic allergic alveolitis, according to the following criteria: a positive history and 2 or more of the following findings: increase in leucocyte count, rise in temperature and decrease in inspiratory vital capacity (IVC) and total lung capacity (TLC).

Adult↗