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PubMed1998

Pulmonary function after posterior retroperitoneoscopic surgery.

Pulmonary function tests were performed in 12 patients who underwent posterior retroperitoneoscopic surgery, before and on the 3rd and 7th days after operation. Forced vital capacity (FVC), forced expiratory volume in 1 second (FEV1), FEV1/FCV, vital capacity (VC), total lung capacity (TLC), residual volume (RV) and functional residual capacity (FRC) were not significantly different between before and after surgery. It is assumed that posterior retroperitoneoscopic surgery could be performed without impairment of pulmonary function after surgery.

Adrenalectomy↗
PubMed2002

Effect of methotrexate on pulmonary function in patients with rheumatoid arthritis--a prospective study.

If given in high doses, methotrexate (MTX), a folate antagonist, could cause pulmonary complications. To evaluate the pulmonary effects of low-dose methotrexate, 55 newly diagnosed patients with rheumatoid arthritis (RA) prescribed with MTX were studied prospectively. A significant reduction in percent predicted values of forced expiratory volume (FEV(1)), forced vital capacity (FVC), total lung capacity (TLC), and functional residual capacity (FRC) was observed after 2 years of MTX treatment. A significant increase in the FEV(1):FVC ratio was also observed. In comparison to the normal annual decline in healthy adults, the actual reduction in observed values in the patients was significantly greater (3.2, 6.3, and 6.7 times normal for FEV(1), FVC, and TLC, respectively). PaO(2) and oxygen saturation showed marginal but significant improvement. It was concluded that low-dose MTX treatment in RA might cause an accelerated decline in lung function. Therefore, periodic monitoring of pulmonary function among RA patients started on MTX could be necessary.

Arthritis, Rheumatoid↗
PubMed2006

Functional and physiologic results of video-assisted thoracoscopic diaphragm plication in adult patients with unilateral diaphragm paralysis.

BACKGROUND: Plication of the hemidiaphragm for unilateral diaphragm paralysis is infrequently performed in adults. Barriers to diaphragm plication have included the perceived need for thoracotomy and uncertainty of the potential benefits. The purpose of this investigation was to assess the effects of video-assisted thoracoscopic diaphragm plication in symptomatic adult patients with unilateral diaphragm paralysis. METHODS: Patients with unilateral diaphragm paralysis underwent an evaluation that included a chest radiograph, fluoroscopic sniff test, pulmonary spirometry, and the Medical Research Council (MRC) dyspnea score. Patients with symptomatic unilateral diaphragm paralysis present for at least 6 months were offered video-assisted thoracoscopic diaphragm plication. Patients who underwent diaphragm plication as well as those who declined surgery were reassessed at 6 months with a chest radiograph, spirometry, and the MRC dyspnea score. RESULTS: Twenty-five patients underwent left (19) or right (6) diaphragm plication through video-assisted thoracoscopic diaphragm plication (22) or thoracotomy (3). There were no operative deaths. Mean hospital length of stay for diaphragm plication was 3.7 days for video-assisted thoracoscopic diaphragm plication and 5.4 days for thoracotomy. After diaphragm plication, mean forced vital capacity, forced expiratory volume at 1 second, functional residual capacity, and total lung capacity improved by 17%, 21.4%, 20.3%, and 16.1%, respectively (p < 005) at 6 months. Mean MRC dyspnea scores also significantly improved in the operative cohort (p < 0001). Seventeen patients in the surgical cohort had returned to work at 6 months. Seven patients treated without surgery displayed a trend toward more frequent hospitalizations and deteriorating pulmonary spirometry and MRC dyspnea scores during the follow-up period. CONCLUSIONS: Plication of the hemidiaphragm using minimally invasive techniques produced significant improvements in patients' functional status, pulmonary spirometry, and MRC dyspnea scores. Video-assisted thoracoscopic diaphragm plication should be considered appropriate therapy in symptomatic adult patients with unilateral diaphragm paralysis.

Adult↗
PubMed2003

Kinematic modeling of single muscle fiber during diaphragm shortening.

Understanding the kinematics of the diaphragm muscle at the single fiber level is important in understanding the mechanics of its membrane. Nevertheless, the geometric parameters of single muscle fiber contraction remain poorly understood. We modeled the kinematics of a single muscle fiber of the diaphragm to determine the relationships among fiber shape, perimeter of the fiber cross-section, and apparent surface area of the fiber during muscle shortening. We used the models to identify which constraints on the geometric parameters are most consistent with physiological data on diaphragmatic muscle shortening. Our kinematic models use isovolumic fibers with elliptical cross-sections, and these models have the following properties: (1) constant cross-sectional shape, (2) inextensible cross-sectional perimeter, (3) constant cross-sectional transverse dimension, or (4) constant apparent surface area. These models were investigated during muscle shortening of the diaphragm from functional residual capacity to total lung capacity. The model that matches physiologic data best has zero transverse strain and has a relationship between fiber shape and muscle shortening consistent with published data on single muscle fiber mechanics.

Anatomy, Cross-Sectional↗
PubMed1999

Pulmonary function for pectus excavatum at long-term follow-up.

PURPOSE: The aim of this article was to assess whether and to what extent pulmonary function recovered to normal degree postoperatively and to investigate the changes in pulmonary function after surgical correction and the value of surgical correction. METHODS: A total of 27 patients who could be questioned and examined in person at the outpatient department of our hospital were included in this study. Of these patents, 24 were boys and 3 were girls. Their ages ranged from 3 to 16 years (mean, 8.67) at follow-up. The mean age at surgery was 4 years, and mean years of follow-up was 6.8. Pulmonary functional measurements included in vital capacity (VC), total lung capacity (TLC), residual volume (RV), functional residual capacity (FRC), RV-TLC ratio, maximal voluntary ventilation (MVV), force ventilatory capacity (FVC), forced expiratory volume in one second (FEV1), maximal midexpiratory flow curve (MMEF), maximal expiratory flow in 75% vital capacity (V75), maximal expiratory flow in 50% vital capacity (V50), maximal expiratory flow in 25% vital capacity (V25), and breathing reserve ratio (BR). RESULTS: TLC, FRC, MVV, MMEF, V75, and V50 values were not different from the normal values. IVC, FVC, FEV1, and V25 values were decreased significantly compared with the normal values. The RV and RV-TLC were high in 87.5% cases. CONCLUSIONS: Preoperative symptoms obviously improved after operation. There was little airway obstruction in the patients postoperatively. The patients with pectus excavatum should be operated on as soon as possible.

Adolescent↗
PubMed2006

[Quantifying plasma levels of transforming growth factor beta1 in idiopathic pulmonary fibrosis].

OBJECTIVE: Transforming growth factor ss1 (TGF-ss1) is one of the key profibrotic mediators in the pathogenesis of idiopathic pulmonary fibrosis (IPF). The purpose of this study was to investigate the prognostic value of quantifying TGF-ss1 levels in patients with IPF. PATIENTS AND METHODS: We conducted a prospective study of 29 IPF patients and 27 healthy controls. Enzyme-linked immunosorbent assays were used to quantify TGF-ss1 levels. RESULTS: Mean (SD) TGF-ss1 levels were significantly higher in the IPF patients than in the control subjects (11.1 [7.5] ng/mL vs 4 [2.4] ng/mL; P< .01). Weak inverse correlations were observed between TGF-ss1 levels and both forced vital capacity and total lung capacity. Thirteen IPF patients were evaluated at 8 (1.2) months (range, 5-9 months). The mean TGF-ss1 level was 18.2 (15) ng/mL and there were no significant differences with respect to the initial measurement of 11.1 (7.5) ng/mL. No correlation was observed between changes in respiratory function and changes in TGF-ss1 levels. CONCLUSIONS: Although plasma levels of TGF-beta1 were high in the patients with IPF, they do not appear to be a useful prognostic marker of disease activity or therapeutic response.

Aged↗
PubMed2004

Sensitivity analysis of respiratory parameter estimates in the constant-phase model.

The constant-phase model is increasingly used to fit low-frequency respiratory input impedance (Zrs), highlighting the need for a better understanding of the use of the model. Of particular interest is the extent to which Zrs would be affected by changes in parameters of the model, and conversely, how reliable are parameters estimated from model fits to the measured Zrs. We performed sensitivity analysis on respiratory data from 6 adult mice, at functional residual capacity (FRC), total lung capacity (TLC), and during bronchoconstriction, obtained using a 1-25 Hz oscillatory signal. The partial derivatives of Zrs with respect to each parameter were first examined. The limits of the 95% confidence intervals, 2-dimensional pairwise and p-dimensional joint confidence regions were then calculated. It was found that airway resistance was better estimated at FRC, as determined by the confidence region limits, whereas tissue damping and elastance were better estimated at TLC. Airway inertance was poorly estimated at this frequency range, as expected. During methacholine-evoked pulmonary constriction, there was an increase in the uncertainty of airway resistance and tissue damping, but this can be compensated for by using the relative (weighted residuals) in preference over the absolute (unweighted residuals) fitting criterion. These results are consistent with experimental observation and physiological understanding.

Airway Resistance↗
PubMed2004

Long-term pulmonary function abnormalities and survival after allogeneic marrow transplantation.

We studied long-term pulmonary function testing (PFT) in a retrospective cohort of 6-month survivors of allogeneic marrow transplant (BMT) between 1980 and 1997. Of 593 patients, 73, 71 and 65% had adequate data to assess for obstruction, restriction and diffusion impairments respectively. Over 5 years, mean declines in 1-s forced expiratory volume/forced vital capacity (FEV1/FVC), total lung capacity (TLC) and diffusion were 4, 7 and 17%, respectively. TLC and diffusion tended to subsequently increase. In all, 6, 12 and 35% of patients met criteria for obstruction, restriction and impaired diffusion, respectively. Obstruction was less common in recent transplants (5 vs 15%, P=0.004), while restriction and diffusion impairment rates remained stable. There was significantly greater mortality with obstruction (HR 2.0 (1.04-3.95)), and a nonstatistically significant higher mortality rate with restriction (HR 1.6 (0.95-2.75)), but not with impaired diffusion (HR=0.99 (0.65-1.50)). cGVHD (OR 16.7 (2.2-129.8)) and busulfan (OR 2.9 (1.01-8.24)) were associated with obstruction. Marrow from nonsibling or mismatched donors (OR 4.9 (2.2-10.7)) was associated with restriction. In summary, after BMT, decreased diffusion capacity is common and benign; obstruction has decreased in frequency, is rare without cGVHD, and is associated with mortality; nonsibling and mismatched donor are risk factors for restriction.

Acute Disease↗
PubMed2000

A prospective evaluation of pulmonary function in patients with adolescent idiopathic scoliosis relative to the surgical approach used for spinal arthrodesis.

STUDY DESIGN: A prospective evaluation of pulmonary function in patients with adolescent idiopathic scoliosis undergoing surgical correction. OBJECTIVES: 1) To evaluate prospectively, at regular intervals, the changes in pulmonary function after surgical arthrodesis of primary thoracic and double primary thoracic-lumbar (double major) types of adolescent idiopathic scoliosis in a homogeneous population; 2) to compare the changes in pulmonary function after surgical correction relative to the surgical approach used for spinal arthrodesis; and 3) to determine if short- to midterm morbidity with respect to pulmonary function is associated with the type of surgical approach used for spinal arthrodesis. SUMMARY OF BACKGROUND DATA: The effect of surgical correction on the pulmonary function of patients with adolescent idiopathic scoliosis is controversial. Studies have shown improvement, decline, or no change in pulmonary function after surgical correction of idiopathic scoliosis. METHODS: Ninety-eight patients with adolescent idiopathic scoliosis undergoing surgical treatment at the authors' institution were prospectively evaluated with pulmonary function tests assessing volume (forced vital capacity and total lung capacity) and flow (forced expiratory volume in 1 second). Pulmonary functions were evaluated before surgery and after surgery at 3 months, 1 year, 2 years, and at the final follow-up visit. All patients were divided into four groups depending on the surgical approach used for spinal fusion: Group 1 (n = 47) underwent a posterior spinal fusion with iliac crest bone graft; Group 2 (n = 33) underwent a posterior spinal fusion with rib resection thoracoplasty; Group 3 (n = 7) underwent an anterior spinal fusion with a rib resection thoracotomy; and Group 4 (n = 11) underwent a combined anterior and posterior spinal fusion with autogenous rib and iliac crest graft used, respectively. RESULTS: Patients in Group 1 had improved pulmonary function values at 3 months after surgery, whereas patients in Groups 2, 3, and 4 showed a decline at 3 months after surgery. Two years after surgery, Group 1 had significantly improved pulmonary function values (P < 0.0001), whereas the pulmonary function values of patients in Groups 2, 3, and 4 had returned to preoperative values. CONCLUSIONS: 1) Patients with chest cage disruption during surgical treatment showed a decline in pulmonary function at 3 months after surgery. 2) In contrast, patients without chest cage disruption showed an improvement in pulmonary function at 3 months after surgery. 3) Irrespective of the surgical approach used for spinal arthrodesis, postoperative pulmonary function tests (absolute values) returned to preoperative values at 2 years after surgery. 4) Patients who had no chest cage disruption experienced a significantly greater improvement in two of their pulmonary function values at 2 years after surgery than patients with chest cage disruption.

Adolescent↗
PubMed1987

The effect of thoracic epidural analgesia on respiratory function after cholecystectomy.

To assess the effect of thoracic epidural analgesia (TEA) on postoperative respiratory function and pulmonary complications, a prospective randomized trial was conducted in patients undergoing cholecystectomy. One hundred patients were allocated to TEA (n = 30), TEA + general anesthesia (TEA + GA) (n = 30), or general anaesthesia (GA) (n = 40) groups. Respiratory function was analysed by measuring forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1), functional residual capacity (FRC), total lung capacity (TLC), peak expiratory flow (PEF) in the supine and sitting postures, and arterial blood gases. Postoperative pulmonary complications were carefully documented. TEA significantly prevented the postoperative deterioration of respiratory function as compared with general anaesthesia. FVC, FEV1 and PEF decreased by 20% in patients receiving TEA, in contrast to 55% in patients after GA on the day of operation. This improvement continued until the 2nd day after operation, when FVC, FEV1 and PEF and their recovery rates were equal in all groups. In the sitting posture the preoperative FVC, FEV1 and PEF were about 10% greater than in the supine position. After operation, this difference was further increased. The preoperative difference of 27% in FRC between the sitting and supine postures was maintained after operation. PaO2 decreased by 0.8 kPa after TEA, by 1.5 kPa after TEA + GA with the lowest value on the 2nd postoperative day and by 1.5 kPa after GA, with the lowest value immediately after operation. Simultaneous hypercarbia indicated hypoventilation, which may have contributed to impaired respiratory function on the following days.(ABSTRACT TRUNCATED AT 250 WORDS)

Analgesia↗
PubMed1978

Pulmonary artery pressure in thoracic scoliosis during and after exercise while breathing air and pure oxygen.

Pulmonary artery catheterisation was carried out in 25 scoliotics aged 13 to 67 years (mean 30.7). Each then performed a progressive exercise test breathing air, and 11 performed a similar test breathing pure oxygen. The mean pulmonary artery pressure (PAP) increased linearly with oxygen uptake (VO2) and with the work rate. The pressure responses have been described in terms of ther intercept and rate of rise of pressure (sPAP/VO2 and sPAP/work rate). sPAP/VO2 was unrelated to the anatomical features of the scoliosis, or to PaO2. It was inversely related to vital capacity, functional residual capacity, and total lung capacity. Inspiration of pure oxygen lowered the resting pressure by a mean of 3.2 mmHg but only decreased sPAP/work rate by 9%. The maximum pressure reached during exercise was diminished by a mean of 5.2 mmHg when pure oxygen was breathed. The mean pressures were shown to fall exponentially after exercise. The time constants were proportional to sPAP/VO2 and to the final pressure reached during exercise. Inspiration of pure oxygen did not effect the time constants but decreased the post-exercise pressure load by lowering the final pressure during exercise.

Adolescent↗
PubMed1976

Ventilatory muscle strength and endurance training.

We studied respiratory mechanics in young volunteers before and after 5-wk training programs limited to the ventilatory muscles. Four strength trainers (S) performed repeated static maximum inspiratory and expiratory maneuvers against obstructed airways. Four endurance trainers (E) performed voluntary normocarbic hyperpnea to exhaustion. Subjects spent 30-45 min each day in these exercises, 5 days a week. Four control subjects (C) did no training. We attempted to minimize the effect of learning. S increased pressure maximums by about 55%, but vital capacity and total lung capacity by only about 4%. Initially all subjects could sustain hyperpnea at about 81% of their control 15-s maximum voluntary ventilation (MVV) for 15 min; E increased this to about 96% and increased their MVV by 14% as well. No other statistically significant changes were recognized in any group. We conclude that ventilatory muscle strength or endurance can be specifically increased by appropriate ventilatory muscle training programs.

Adult↗
PubMed1989

Interaction of inhaled LTC4 with histamine and PGD2 on airway caliber in asthma.

To investigate possible mediator interaction in asthma, the effect of inhaled leukotriene (LT) C4 on bronchoconstriction provoked by histamine and prostaglandin (PG) D2 was studied in nine asthmatic subjects. The provocation doses of histamine, PGD2, and LTC4 required to produce a 12.5% decrease in baseline forced expiratory volume in 1 s (FEV1, PD12.5) and to further this fall to 25% (PD25-12.5) were determined. On three subsequent occasions, subjects inhaled either the PD12.5 LTC4 plus vehicle or vehicle plus the PD25-12.5 of either histamine or PGD2, and FEV1 and maximal flow at 70% of vital capacity below total lung capacity after a forced partial expiratory maneuver (Vp30) followed for 45 min. From these results, predicted time-course curves for LTC4 with histamine and LTC4 with PGD2 were calculated. On two final occasions, airway caliber was followed for 45 min after inhalation of the PD12.5 LTC4 followed by the PD25-12.5 of either histamine or PGD2. During the first 9 min after LTC4-histamine and LTC4-PGD2, the decreases in airway caliber were greater than the calculated predicted response. This interaction, although small, was significant with LTC4-PGD2 for both FEV1 (P = 0.01) and Vp30 (P less than 0.05) and with LTC4-histamine for Vp30 (P less than 0.05) but not for FEV1 (P less than 0.05). We conclude that inhaled LTC4 interacts synergistically with histamine and PGD2 and that this effect, although small, may be a relevant interaction in asthma.

Administration, Inhalation↗
PubMed1990

Respiratory changes in diaphragmatic intramuscular pressure.

We attempted to measure diaphragmatic tension by measuring changes in diaphragmatic intramuscular pressure (Pim) in the costal and crural parts of the diaphragm in 10 supine anesthetized dogs with Gaeltec 12 CT minitransducers. During phrenic nerve stimulation or direct stimulation of the costal and crural parts of the diaphragm in an animal with the chest and abdomen open, Pim invariably increased and a linear relationship between Pim and the force exerted on the central tendon was found (r greater than or equal to 0.93). During quiet inspiration Pim in general decreased in the costal part (-3.9 +/- 3.3 cmH2O), whereas it either increased or slightly decreased in the crural part (+3.3 +/- 9.4 cmH2O, P less than 0.05). Similar differences were obtained during loaded and occluded inspiration. After bilateral phrenicotomy Pim invariably decreased during inspiration in both parts (costal -4.3 +/- 6.4 cmH2O, crural -3.1 +/- 0.6 cmH2O). Contrary to the expected changes in tension in the muscle, but in conformity with the pressure applied to the muscle, Pim invariably increased during passive inflation from functional residual capacity to total lung capacity (costal +30 +/- 23 cmH2O, crural +18 +/- 18 cmH2O). Similarly, during passive deflation from functional residual capacity to residual volume, Pim invariably decreased (costal -12 +/- 19 cmH2O, crural -12 +/- 14 cmH2O). In two experiments similar observations were made with saline-filled catheters. We conclude that although Pim increases during contraction as in other muscles, Pim during respiratory maneuvers is primarily determined by the pleural and abdominal pressures applied to the muscle rather than by the tension developed by it.

Animals↗
PubMed1990

Inhaled PAF fails to induce airway hyperresponsiveness to methacholine in normal human subjects.

The effects of three increasing doses of platelet-activating factor (PAF) on airway caliber and methacholine bronchial responsiveness were studied. On separate occasions nine normal subjects inhaled a single cumulative provocation concentration of methacholine (control) causing a 40% fall (PC40 Vp30) in maximum expiratory flow rate at 70% of base-line vital capacity below total lung capacity during a partial forced expiratory maneuver or 100 or 200 micrograms PAF, and seven subjects inhaled a further dose of 400 micrograms PAF. Methacholine responsiveness was measured before, at 3 and 7 h, then on days 1, 2, 3, 4, 7, 10, and 14 after each challenge. The maximum falls in Vp30 appeared dose dependent, but a significant difference between the magnitude of the responses was only observed between the 400- and 100-micrograms PAF dose (P less than 0.05). During the control period repeated methacholine challenges resulted in a progressive increase in cumulative provocation concentration of an agonist causing a 20% fall in forced expiratory volume in 1 s from base line, reaching significance on days 1 and 2 (2.44- and 2.4-fold of base line, respectively, P less than 0.01) before returning to base line on day 7. No difference was seen in methacholine responsiveness after any of the three doses of PAF compared with that after the control. We conclude that PAF causes dose-dependent bronchoconstriction but does not change airways responsiveness to methacholine and that repeated high-dose methacholine challenge leads to loss of responsiveness to this agonist.

Administration, Inhalation↗
PubMed1992

Heterogeneous airway tone in asthmatic subjects.

We examined the effect of volume history on the dynamic relationship between airways and lung parenchyma (relative hysteresis) in 20 asthmatic subjects. The acoustic reflection technique was employed to evaluate changes in airway cross-sectional areas during a slow continuous expiration from total lung capacity to residual volume and inspiration back to total lung capacity. Lung volume was measured continuously during this quasi-static maneuver. We studied three anatomic airway segments: extra- and intrathoracic tracheal and main bronchial segments. Plots of airway area vs. lung volume were obtained for each segment to assess the relative magnitude and direction of the airway and parenchymal hysteresis. We also performed maximal expiratory flow-volume and partial expiratory flow-volume curves and calculated the ratio of maximal to partial flow rates (M/P) at 30% of the vital capacity. We found that 10 subjects (group I) showed a significant predominance of airway over parenchymal hysteresis (P < 0.005) at the extra- and intrathoracic tracheal and main bronchial segments; these subjects had high M/P ratios [1.53 +/- 0.27 (SD)]. The other 10 subjects (group II) showed similar airway and parenchymal hysteresis for all three segments and significantly lower M/P ratios (1.16 +/- 0.20, P < 0.01). We conclude that the effect of volume history on the relative hysteresis of airway and lung parenchyma and M/P ratio at 30% of vital capacity in nonprovoked asthmatic subjects is variable. We suggest that our findings may result from heterogeneous airway tone in asthmatic subjects.

Adolescent↗
PubMed1997

Three-dimensional reconstruction of human diaphragm with the use of spiral computed tomography.

We developed a technique of diaphragm imaging by using spiral computed tomography, and we studied four normal subjects who had been previously investigated with magnetic resonance imaging (A. P. Gauthier, S. Verbanck, M. Estenne, C. Segebarth, P. T. Macklem, and M. Paiva. J. Appl. Physiol. 76: 495-506, 1994). One acquisition of 15- to 25-s duration was performed at residual volume, functional residual capacity, functional residual capacity plus one-half inspiratory capacity, and total lung capacity with the subject holding his breath and relaxing. From these acquisitions, 20 coronal and 30 sagittal images were reconstructed at each lung volume; on each image, diaphragm contour in the zone of apposition and in the dome was digitized with the software Osiris, and the digitized silhouettes were used for three-dimensional reconstruction with Matlab. Values of length and surface area for the diaphragm, the dome, and the zone of apposition were very similar to those obtained with magnetic resonance imaging. We conclude that satisfactory three-dimensional reconstruction of the in vivo diaphragm may be obtained with spiral computed tomography, allowing accurate measurements of muscle length, surface area, and shape.

Adult↗
PubMed1981

Pulmonary changes during marathon training: a longitudinal study.

The purposes of this study were (1) to confirm whether there were any differences between observed and predicted scores based on age, height, and sex in forced vital capacity (FVC), 1-second forced expiratory volume (FEV1.0), FEV1.0/FVC ratio, functional residual capacity (FRC), total lung capacity (TLC, FRC/TLC ratio, residual volume (RV), RV/TLC ratio, diffusing capacity of lungs for carbon monoxide (DCO), alveolar-capillary permeability (k'CO), and alveolar volume (VA) for 2 middle-aged non-smoking men who trained for and competed in three annual 26.2-mile marathon races and (2) to determine the magnitude and direction of changes in the observed scores for the three annual tests. The subjects trained from 45 to 70 miles/week for 52 weeks during the 3-year period. In the week after their annual marathon run they were measured in the above pulmonary variables. For the 3-year period of training subject A improved five pulmonary variables (TLC, FRC, FRC/TLC ratio, DCO, and k'CO) and had small decreases in function of the other six variables. Likewise, subject B improved three pulmonary variables (FRC, FRC/TLC ratio, and k'CO) and had small decreases in function of the other eight variables. It is not possible to draw statistical inferences to other populations from this data, but it does indicate that these subjects are in a state of good-to-great pulmonary health. Although random variations may account for some of the changes for these 2 subjects, it is possible that marathon training has inhibited some of the deterioration in pulmonary function as predicted from the regression with age by Kory.

Adult↗