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PubMed2001

Ministernotomy versus complete sternotomy for coronary bypass operations: no difference in postoperative pulmonary function.

OBJECTIVES: Less-invasive approaches in cardiac operations offer certain cosmetic advantages, but it is unclear whether there are additional positive effects with regard to the postoperative recovery of patients. The aim of this prospective and randomized study was to ascertain whether partial inferior midline sternotomy can improve pulmonary function, one of the best quantifiable parameters of postoperative recovery, after coronary artery bypass operations when compared with the standard full midline approach. METHODS: One hundred patients scheduled for elective coronary artery bypass grafting were randomized either for a full median sternotomy (standard sternotomy group, n = 50) or for a partial inferior sternotomy (ministernotomy group, n = 50). The following pulmonary features were assessed: vital capacity, forced expiratory volume, percentage of forced expiratory volume from vital capacity, total lung capacity, residual volume, maximum inspiratory pressure, and maximum expiratory pressure. Tests were performed preoperatively and on the fourth and tenth postoperative days. RESULTS: On the fourth postoperative day, both groups had a significant decrease in vital capacity (percentage of predicted values) when compared with preoperative values (preoperative vs fourth day: standard sternotomy group, 87.8% +/- 14.3% vs 42.1% +/- 10.2% [P <.0001]; ministernotomy group, 84.5% +/- 14.3% vs 41.5% +/- 11.8% [P <.0001]), with a significant tendency for recovery from the fourth to the tenth postoperative day (fourth vs tenth postoperative day: standard sternotomy group, 42.1% +/- 10.2% vs 66.3% +/- 12.3% [P =.001]; ministernotomy group, 41.5% +/- 11.8% vs 61.3% +/- 13.1 % [P =.002]). There were no differences in any test results between the groups on either the fourth or the tenth postoperative day. CONCLUSION: A less-invasive approach for coronary artery bypass operations with a partial inferior sternotomy does not improve early postoperative pulmonary function when compared with the conventional approach with a full sternotomy.

Coronary Artery Bypass↗
PubMed1989

Organ manifestations in 100 patients with progressive systemic sclerosis: a comparison between the CREST syndrome and diffuse scleroderma.

Internal organ function, biochemical, and immunological variables were assessed in 100 patients with progressive systemic sclerosis (PSS), 37 with diffuse scleroderma and 63 with the CREST syndrome. The frequency of oesophageal symptoms and dysmotility did not differ between the two subsets, but patients with diffuse scleroderma had more pronounced motility disturbances. Calcinosis, Raynaud's phenomenon, and telangiectasia were equally frequent in the two groups. Vital capacity, total lung capacity, and static lung compliance were lower among patients with diffuse scleroderma (p less than 0.001), who also had a higher frequency of lung fibrosis (p less than 0.001) and cardiomegaly (p less than 0.01). Sixty eight per cent of the patients with diffuse scleroderma and 62% of those with the CREST syndrome had a positive antinuclear antibody test, which was associated with oesophageal hypomotility (p less than 0.001), fat malabsorption (p less than 0.01) and pulmonary dysfunction (p less than 0.05). Thus, the severity of organ manifestations varied not only with the form of PSS, but also with the absence/presence of antinuclear antibody. This study shows that the term 'CREST syndrome' could be replaced by 'limited cutaneous systemic sclerosis'.

Adult↗
PubMed1993

Effects of weight loss on pulmonary function in obese men with obstructive sleep apnoea syndrome.

The effects of long-term behaviour modification of obesity on pulmonary function was studied in eight men with obstructive sleep apnoea syndrome (initial mean body mass index [BMI] 41.8 kg m-2) before and after a mean weight loss of 20 +/- 7 (SD) kg. Mean arterial PCO2 fell from 6.3 +/- 1.2 to 5.5 +/- 0.6 kPa (P < 0.05) and concomitant significant improvements were found in vital capacity, total lung capacity, functional residual capacity and forced expired volume (FEV 1.0). The study suggests that weight loss per se, rather than the method of choice to achieve weight loss, results in clinically significant improvement of pulmonary function in obese men.

Adult↗
PubMed1977

Pulmonary function in obese patients scheduled for jejuno-ileostomy.

Preoperative pulmonary parameters were evaluated in 37 extremely obese but otherwise healthy patients. They were on average 100.9% overweight. X-ray of the chest, electrocardiograms, and residual volume, vital capacity, total lung capacity, maximum breathing capacity, forced expired volume in 1 second, and related ratios were all within the normal range. The alveolar-arterial oxygen gradient and the arterial carbon dioxide tension were also within the normal range. The only abnormal finding was a substantially reduced arterial oxygen tension. It is suggested that the measurement of functional residual capacity, closing volume, and the slope of the alveolar plateau (phase III in the single breath nitrogen washout technique) might give more valuable information.

Adult↗
PubMed1994

Specification and quantitation of circulating immune complexes in the serum of patients with active pulmonary sarcoidosis.

BACKGROUND: Circulating immune complexes can be elevated in serum samples of patients with sarcoidosis and are associated with disease activity, but their diagnostic significance is not understood. METHODS: The different classes of circulating immune complexes containing immunoglobulin A, G, or M, and the content of complement in circulating immune complexes (polyethylene glycol precipitation) as well as levels of complement binding circulating immune complexes (complement binding assay) were determined in 19 patients with active, untreated pulmonary sarcoidosis. The results were compared with other parameters in the serum (soluble interleukin 2 receptor, angiotensin converting enzyme, immunoglobulin A, G, and M) and the bronchoalveolar lavage fluid (lymphocytes, helper cells, suppressor cells, activated T cells), and with radiological stage and functional parameters (FEV1, vital capacity, total lung capacity, transfer coefficient (KCO), and the alveolar-arterial oxygen difference during exercise). RESULTS: In all patients circulating immune complexes could be detected by polyethylene glycol precipitation and were similar to control subjects. The content of C1q in circulating immune complexes was higher than in controls, yet in all but one of the cases was still within normal limits. In contrast, elevated levels of complement binding circulating immune complexes were found in 67% of the patients. No correlation was seen between circulating immune complexes and any of the other parameters in the serum, bronchoalveolar lavage fluid, or lung function values. No differences were found between radiological type I and II presentations of sarcoidosis. CONCLUSIONS: The complement binding assay showed a much higher sensitivity for the detection of circulating immune complexes in active pulmonary sarcoidosis than the polyethylene glycol precipitation method. As there was no correlation between levels of circulating immune complexes and other parameters of the disease they are probably not useful for the assessment of disease activity.

Adult↗
PubMed1993

Airway-parenchymal interdependence and bronchial responsiveness in two highly inbred rat strains.

To investigate if airway-parenchymal interdependence may account for differing bronchial responsiveness between inbred rat strains, Fisher and Lewis 12-wk-old male rats were anesthetized, tracheostomized, and placed in a pressure plethysmograph. Functional residual capacity, total lung capacity [lung volume at transpulmonary pressure (PL) of 30 cmH2O], and specific compliance were determined and were found to be similar. Rats were paralyzed and mechanically ventilated. Concentration-response curves were constructed by calculating lung resistance (RL) and lung elastance (EL) after nebulization of saline and then doubling doses of methacholine (0.0625-512 mg/ml). In Fisher (n = 8) and Lewis (n = 7) rats RL and EL were again determined at a lung volume corresponding to 2 cmH2O PL above FRC. The doubling, maximal, and half-maximal effective concentrations were determined for RL and EL. The doubling of effective concentrations of RL and EL were significantly less for Fisher rats. Other groups of Fisher (n = 5) and Lewis (n = 5) rats were similarly exposed to three concentrations of methacholine (64, 128, and 256 mg/ml), and determinations of RL and EL were made at lung volume corresponding to PL of 0, 2, 4, and 8 cmH2O. In both groups, Lewis rats exhibited a significant effect of volume on maximal RL and EL, whereas Fisher rats did not. The absence of volume effect on bronchoconstriction in the hyperresponsive Fisher strain is consistent with the hypothesis that altered airway-parenchymal interdependence contributes to bronchial hyperresponsiveness.

Administration, Inhalation↗
PubMed1995

Effect of surface forces on oscillatory behavior of lungs.

The effect of alveolar surface tension on lung dynamic behavior was investigated by measuring total lung and tissue impedances in excised rabbit lungs at breathing frequencies of 0.2-0.8 Hz and tidal volumes of 10, 20, and 30 ml before and after lavage with 3-dimethyl siloxane, which provided a constant surface tension of 16 dyn/cm. The lungs were oscillated around the mean deflation pressures of 5 (control) and 8 cmH2O (lavaged), i.e., lung volume of 60% of total lung capacity. The total lung impedance was calculated from measurements of pressure and airflow at the trachea, and tissue impedance was measured by the alveolar capsule technique. The airway contribution was obtained as the difference between total lung and tissue impedances. In the lavaged lungs, dynamic elastance (Edyn) decreased and tissue resistance (Rti) increased relative to the control values over the entire frequency range. Airway resistance increased at the higher flow rates only. The decrease in Edyn could be attributed to the absence of surface film elastance in the lavaged lungs. The increase in airway resistance could be attributed to accentuated flow dependence due to changes in airway geometry and residual lavage liquid. However, the most intriguing result was the increase in Rti in the lavaged lungs. It could be attributed to altered mechanics at the alveolar duct level after lavage. It is concluded that dissipative properties of lung tissue are major determinants of Rti, whereas elastic properties of both tissue and surface film are important determinants of Edyn.

Airway Resistance↗
PubMedDate not supplied

Clinical patterns of diffuse parenchymal lung disease in Kuwait: a prospective study.

OBJECTIVE: To report our experience of the clinicopathological patterns of diffuse parenchymal lung disease (DPLD). SUBJECTS AND METHODS: Over a 4-year period, 75 patients (41 males, 34 females), aged 13-76 years, who were referred to Mubarak Al-Kabeer and the Chest Diseases Hospitals, Kuwait with a diagnosis of diffuse lung disease, were included in the study. After a comprehensive history and physical examination, further investigations were done, including hematological and immunological profiles, sputum and bronchoalveolar lavage fluid examination, chest radiograph, high resolution computed tomography (HRCT), pulmonary function test and lung biopsy. RESULTS: Of the 75 patients 60 (80%) were over 40 years of age. The duration of symptoms in 34 patients (45%) was less than 6 months and longer than 1 year in 28 (37.7%) patients. Twenty-five of the patients were cigarette smokers. The mean forced lung capacity (FVC), total lung capacity and diffusing capacity for carbon monoxide were less than 60% of the predicted values in most patients. There was a significant difference in mean FVC value between smokers and nonsmokers (p < 0.05). The HRCT findings were at an advanced stage in 65 patients, with additional honeycombing in 21 of the 65 patients. Idiopathic pulmonary fibrosis was the most common cause of DPLD, occurring in 52 patients, followed by sarcoidosis and collagen vascular diseases. CONCLUSION: DPLD was observed predominantly in middle aged and elderly patients, due probably to increasing industrialization in the country. The role of cigarette smoking as a contributory factor remains unclear.

Adult↗
PubMed1999

Mechanisms underlying effects of nocturnal ventilation on daytime blood gases in neuromuscular diseases.

The hypothesis that, in neuromuscular and chest wall diseases, improvement in central respiratory drive explains the effects of night-time ventilation on diurnal gas exchanges was tested. The effects at 6 months, 1, 2 and 3 yrs of intermittent positive pressure ventilation (IPPV) on arterial blood gas tension, pulmonary function, muscle strength, sleep parameters, respiratory parameters during sleep and ventilatory response to CO2 were evaluated in 16 consecutive patients with neuromuscular or chest wall disorders. As compared with baseline, after IPPV daytime arterial oxygen tension (Pa,O2) increased (+2.3 kPa at peak effect) and arterial carbon dioxide tension (Pa,CO2) and total bicarbonate decreased (-1.8 kPa and -5 mmol x L(-1), respectively) significantly; vital capacity, total lung capacity, maximal inspiratory and expiratory pressures and alveolar-arterial oxygen gradient did not change; the apnoea-hypo-opnoea index and the time spent with an arterial oxygen saturation (Sa,O2) value <90% decreased (-24 and -101 min, respectively), sleep efficiency and mean Sa,O2 increased (+16% and +5%, respectively); and ventilatory response to CO2 increased (+4.56 L x min(-1) x kPa(-1)) significantly. The reduction in Pa,CO2 observed after IPPV correlated solely with the increase in the slope of ventilatory response to the CO2 curve (r=-0.68, p=0.008). In neuromuscular or chest wall diseases, improvement of daytime hypoventilation with nocturnal intermittent positive pressure ventilation may represent an adaptation of the central chemoreceptors to the reduction of profound hypercapnia during sleep or reflect change in the quality of sleep.

Adult↗
PubMed1979

Serum factor in cystic fibrosis: correlation with clinical parameters.

The relationship between the activity of the cystic fibrosis serum ciliary dyskinesia factor, detected by the rabbit tracheal bioassay, and clinical status of the patient has been investigated in children, 1-24 years old, with cystic fibrosis. No significant correlation was found between the amount of serum factor activity and age, clinical status assessed by the Schwachman score, pulmonary function (vital capacity, functional residual capacity, total lung capacity, residual volume, maximum breathing capacity, maximal midinspiratory flow, and maximal midexpiratory flow) or blood gas levels (pCO2, pO2). The activity showed no significant relationship to serum galactosyltransferase activity in children with cystic fibrosis.

Adolescent↗
PubMed1993

Improved pulmonary function and exercise tolerance with inspiratory muscle conditioning in children with cystic fibrosis.

This study documented the effect of inspiratory muscle conditioning in children with cystic fibrosis. Subjects, ages 7 to 14 years, were divided into two groups. The experimental group (n = 10) trained at a high pressure load (> or = 29 cm H2O) and the control group (n = 10) trained at a minimal pressure load (< or = 15 cm H2O), using a threshold loading device. Subjects trained 30 min a day for 10 weeks. Pulmonary function, inspiratory muscle strength, and exercise tolerance were measured at the beginning and end of the training period. Pulmonary function was measured by body plethysmography. Inspiratory muscle strength was determined by standard measures of maximal inspiratory pressure against an occluded airway. Exercise tolerance was measured by the length of time subjects could walk on a treadmill. Findings indicated that the experimental group showed significant increases in inspiratory muscle strength, vital capacity, total lung capacity, and exercise tolerance in comparison to the control group.

Adolescent↗
PubMed1989

[Clinical assessment of pulmonary hypertension in collagen diseases].

The occurrence of pulmonary hypertension (PH) has been reported in association with collagen diseases. Because of its grave consequences it is of greatest importance to make an early diagnosis of PH and initiate adequate treatment. For this purpose we have carried out right heart catheterization study to determine pulmonary arterial pressure (PAP), pulmonary vascular resistance (PVR), and cardiac index in thirty-four consecutive patients with collagen diseases including cases of mixed connective tissue disease (MCTD). We also compared the hemodynamic data with clinical pictures and the results of non-invasive cardiopulmonary tests which were done before catheterization study. Pulmonary hypertension as defined by the mean PAP of greater than 20 mmHg was observed in 11 of the 34 cases. PH was observed in five of 6 cases with MCTD and six of 17 cases with PSS including 2 cases with overlapping SLE and PM. The frequencies of positive anti-nRNP antibody, serositis, Raynaud's phenomenon and muscle involvement were significantly higher in cases with PH than in cases without PH. Catheterization study was most useful for diagnosis of cases with mean PAP of less than 25 mmHg, whereas echocardiographic study identified all cases with mean PAP of greater than 25 mmHg. No significant correlation was observed between mean PAP and vital capacity, total lung capacity or diffusion capacity measured as the percent of predicted normal values, which suggests that vascular abnormalities play a more significant role in the pathogenesis of PH than pulmonary fibrosis in collagen diseases.

Adult↗
PubMed1983

Pulmonary function testing. What is 'normal'?

For many years, confusion has existed concerning the normal range for pulmonary function test results. Using statistical guidelines that have been traditionally applied to the interpretation of measured forced vital capacity (FVC) and forced expiratory volume in 1 s (FEV1), we have redefined normal limits for the most common pulmonary function test values, including those for FVC, FEV1, mean forced expiratory flow during the middle half of the FVC, FEV1 as a proportion of FVC, residual volume, functional residual capacity, total lung capacity, diffusion capacity, maximum voluntary ventilation, and peak expiratory flow. Our goal is to provide a simple and consistent scheme for interpretation of pulmonary function test data. We consider the assumptions used to achieve this simplification to be reasonable, as long as their limitations are understood.

Humans↗
PubMed1986

Accuracy of radiographic lung volume using new equations derived from computed tomography.

This study compared radiographic measurements of regional lung volume with corresponding physiologic measurements. The database included 48 normal, supine adults who had previously undergone spirometry and helium-dilution lung volume measurements to determine physiologic functional residual capacity (G-FRC) and total lung capacity (G-TLC). Chest x-rays had also been obtained for these subjects at functional residual capacity and total lung capacity. To calculate radiographic lung volumes at functional residual capacity and total lung capacity (R-FRC and R-TLC, respectively), we traced the lung outline from the chest x-ray, and digitized each outline. We then calculated total and regional lung volumes, using equations previously derived from computed tomographic scans. R-FRC and R-TLC were closely correlated (r = 0.973, maximum SEE 6.8%) with G-FRC and G-TLC, whether or not separate equations were used for regions below the diaphragm. Using only maximum anteroposterior diameter reduced the r-value to 0.957 (SEE 9.6%). The accuracy of our method of radiographic measurement of regional lung volume was validated by the concurrence between the physiologic and radiographic measurements.

Adult↗
PubMed2004

Ventilation asymmetry after transplantation for emphysema: role of chest wall and mediastinum.

After single-lung transplantation for emphysema, the hyperinflated native lung and the graft have different extents and rates of inflation and emptying. This requires that breathing produces asymmetrical expansion of the chest wall, displacement of the mediastinum, or both. In a first study in four seated transplant recipients, we measured the volumes of the two hemithoraces with optoelectronic plethysmography. Functional residual capacity and total lung capacity were identical on the native and transplanted sides, and changes in chest wall volume during CO(2)-induced hyperpnea and FVC maneuvers were similar on both sides. Studies with computerized tomography in three of these patients and in four additional patients in supine posture indicated that the mediastinum was shifted toward the graft at functional residual capacity and total lung capacity. The mediastinum moved toward the native lung during tidal and full inspiration and toward the graft during tidal and forced expiration; additional studies with fluoroscopy showed qualitatively similar changes in upright posture. In summary, the two hemithoraces assume identical static volumes and show similar volume changes during CO(2)-induced hyperpnea and FVC maneuvers in patients with single-lung transplantation for emphysema; displacement of the mediastinum accommodates part, if not all, of the unequal lung volumes and asymmetrical ventilation.

Female↗
PubMed1990

Dependence of maximal sniff generated mouth and transdiaphragmatic pressures on lung volume.

The maximal sniff generated mouth and transdiaphragmatic pressures of six healthy volunteers (three women and three men) were measured at various lung volumes between residual volume and 95% of total lung capacity. At residual volume the mean (SD) maximum transdiaphragmatic pressure was 163 (18) cm H2O (1 cm H2O = 0.0981 kPa). With increasing lung volume the maximum pressures generated declined, so that at 95% of total lung capacity the mean pressure was 68 (15) cm H2O. Mouth pressures showed a similar relation to lung volume. At residual volume the mean maximum mouth pressure was 74 (8) cm H2O, compared with 38 (6) cm H2O at 95% of total lung capacity. The relation between pressure and lung volume was linear for measurements at lung volume levels between residual volume and 85% of total lung capacity; values at 95% of total lung capacity, however, were lower than predicted from the linear regression of the other points. The use of a second order polynomial regression showed a higher coefficient of determination in all cases (0.72 and 0.69 for transdiaphragmatic and mouth pressures on the basis of all pressure values for all subjects). Sniff generated mouth and transdiaphragmatic pressures show a predictable dependence on lung volume, supporting their use as measures of global inspiratory muscle power and diaphragm strength respectively.

Adult↗
PubMed2003

Pulmonary compensatory indexes in children and adolescents with idiopathic scoliosis I degree.

Spirometric and plethysmographic examinations were performed in two groups of children. Group I: 23 children with scoliosis I degree by the Cobb (spinal curvature 17.2 degree) which comprised 12 girls and 11 boys at the age of 8-16 years (the mean age was 11.4 +/- 2.4 yr). The Control Group consisted of 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 performed using Body-plethysmograph with pneumotachograph Jaeger. Total lung capacity (TLC), forced vital capacity (FVC), forced expiratory volume in 1 sec (FEV1), residual volume (RV), intrathoracic gas volume (ITGV) and at the same time curve indexes, dependence of maximum expiratory flow lung volume, MEF75%VC, MEF50%VC, MEF25%VC were determined. Maximum expiratory flows in relation to vital capacity and total lung capacity were defined as so called compensatory indexes. Slightly decreased values of total lung capacity (TLC) and statistically significantly decreased intrathoracic gas volume (ITGV) as well as residual volume (RV) were found in children with scoliosis in early stage. Forced vital capacity (FVC) and forced expiratory volume in 1 sec (FEV1) were statistically significantly higher in comparison to the control group. Compensatory index MEF50%VC/FVC in children in the early stage of scoliosis was statistically significantly decreased in comparison to the control group (p < 0.02).

Adolescent↗
PubMed1998

Crural diaphragm activation during dynamic contractions at various inspiratory flow rates.

The purpose of this study was to evaluate the influence of velocity of shortening on the relationship between diaphragm activation and pressure generation in humans. This was achieved by relating the root mean square (RMS) of the diaphragm electromyogram to the transdiaphragmatic pressure (Pdi) generated during dynamic contractions at different inspiratory flow rates. Five healthy subjects inspired from functional residual capacity to total lung capacity at different flow rates while reproducing identical Pdi and chest wall configuration profiles. To change the inspiratory flow rate, subjects performed the inspirations while breathing across two different inspiratory resistances (10 and 100 cmH2O . l-1 . s), at mouth pressure targets of -10, -20, -40, and -60 cmH2O. The diaphragm electromyogram was recorded and analyzed with control of signal contamination and electrode positioning. RMS values obtained for inspirations with identical Pdi and chest wall configuration profiles were compared at the same percentage of inspiratory duration. At inspiratory flows ranging between 0.1 and 1.4 l/s, there was no difference in the RMS for the inspirations from functional residual capacity to total lung capacity when Pdi and chest wall configuration profiles were reproduced (n = 4). At higher inspiratory flow rates, subjects were not able to reproduce their chest wall displacements and adopted different recruitment patterns. In conclusion, there was no evidence for increased demand of diaphragm activation when healthy subjects breathe with similar chest wall configuration and Pdi profiles, at increasing flow rates up to 1.4 l/s.

Adult↗