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PubMed1999

Diaphragm dimensions after single-lung transplantation for emphysema.

We used three-dimensional reconstructions obtained with spiral computed tomography to measure total diaphragm surface area (Adi), and the surface area of the dome (Ado) and of the zone of apposition (Aap) of the diaphragm in nine patients with single-lung transplantation (SLT) for emphysema and nine normal subjects matched for age, sex, height, and weight. Measurements were obtained at supine FRC, midinspiratory capacity, and TLC. In the normal subjects, Ado and Adi were greater on the right than on the left side, and the right dome was positioned more cranially than the left one, presumably because of the presence of the liver. Compared with either the ipsilateral side in the controls or the native side in the patients, Ado was smaller on the transplanted side because the mediastinum was shifted toward the graft. Adi showed a similar trend. On the other hand, the radius of curvature of the dome in the coronal and sagittal planes was similar on the side of the graft and on the ipsilateral side in the controls. In conclusion, we found that after SLT for emphysema, diaphragm configuration comes back to normal but Ado, and with it Adi, remain smaller than in normal subjects because the mediastinum is displaced toward the graft.

Adult↗
PubMed1975

Pulmonary function evaluation of the lung resection candidate: a prospective study.

In the past, preoperative pulmonary function abnormalities have identified a group of patients in danger of postoperative cardiorespiratory morbidity and mortality. We selected a group of 56 patients, each of whom had a lung mass and had demonstrated significant abnormalities in screening pulmonary function. By using temporary unilateral pulmonary artery occlusion and quantitative macroaggregate lung scanning, we then studied these patients for split pulmonary function. Those patients whose noncancerous lung had a calculated forced expiratory volume in 1 sec greater than 800 ml and a circulation that could accommodate all of the cardiac output without producing hypertension or arterial hypoxemia were offered thoracotomy. Of the 56 patients, we judged 6 to be physiologically inoperable and did not offer surgery. Another 4 patients were not offered surgery, and 4 refused surgery. Forty-two patients underwent surgical exploration-of these, 17 then had a pneumonectomy and 13, a lobectomy. Of the 30 patients resected, 6 died in surgery (4 from respiratory insufficiency). These cardiorespiratory mortality rates (neumonectomy, 17.6 per cent; lobectomy, 7.7 per cent) are lower than those reported previously when patients had equivalent pulmonary function abnormality. A follow-up of 49 of 56 patients revealed that 59 per cent of the patients undergoing either pneumonectomy or lobectomy were still living 1 to 3 years after the resection. Our results suggested that the preoperative testing of split pulmonary function permitted an attempt at surgery in patients who might otherwise be considered inoperable by history, physical examination, screening pulmonary function tests alone.

Aged↗
PubMed1984

Postoperative pulmonary function in children. Comparison of scoliosis with peripheral surgery.

We measured lung volumes, forced expirograms, and arterial blood gases in 2 groups of elective pediatric surgical patients (mean age, 11.4 +/- SD 2.8; n = 11, 12 operations) the day prior to surgery (control) and between the first and eighth postoperative days. The patients were Group I: peripheral surgery (n = 6) and Group II: reconstructive surgery for scoliosis (n = 5). The preoperative lung volumes and forced expiratory volume in one second were within the predicted normal range in both groups, except for a reduction in total lung capacity (TLC) and vital capacity (VC) in Group II. The postoperative lung volumes in Group I were not significantly different from the preoperative volumes. In group II, on postoperative Days 2 and 3, the lung volumes as a percent of preoperative volumes (mean +/- SEM) were VC, 44 +/- 11; functional residual capacity (FRC), 81 +/- 6; residual volume, 124 +/- 10; TLC, 61 +/- 10. Although the mean FRC returned to the preoperative volume by postoperative Days 5 and 6, the VC and its components remained reduced on postoperative Days 5, 6, and 8. We conclude that postoperative lung volume abnormalities are related to the site and magnitude of surgery and associated phenomena, such as pain, and preoperative respiratory function abnormalities.

Adolescent↗
PubMed2004

The influence of lung volume reduction surgery on exercise in patients with COPD.

Although the influence of lung volume reduction surgery (LVRS) on incremental- and constant-power exercise is important in the evaluation of this procedure for patients with chronic obstructive pulmonary disease (COPD), it is rarely reported even in large randomised controlled trials. This report describes 39 patients with severe COPD ((mean +/- SE) forced expiratory volume in one second 32 +/- 2% pred, functional residual capacity 195 +/- 6% pred) who participated in a randomised controlled trial of LVRS and who completed incremental exercise tests at 6 months as well as endurance tests (constant power of 25 +/- 1 W) at 3, 9 and 12 months. Peak oxygen uptake (V'O2,pk) was similar between the treatment (n = 19) and control groups (n = 20) at baseline. After LVRS, the treatment group had a significantly greater V'O2,pk (mean difference (95% CI) 1.28 (0.07-2.50) mL x kg x min(-1)) and power (13 (6-20) W). The treatment group achieved a significantly greater minute ventilation (7.1 (2.9-11.3) L x min(-1)) with a greater tidal volume (0.16 (0.04-0.28) L). Baseline endurance was similar between groups. After surgery, there were significant between-group differences in endurance time, which were maintained at 12 months (7.3 (3.9-10.8) min). Lung volume reduction surgery is associated with an increase in exercise capacity and endurance, as compared with conventional medical treatment.

Aged↗
PubMed2005

Flow limitation and dynamic hyperinflation: key concepts in modern respiratory physiology.

Fashions in ideas, like clothes, come and go. From approximately 1950-1980, physiological research was seen as the key discipline in understanding lung disease and was at the cutting edge of pulmonary science. Subsequently, its importance has been down played amid a widely accepted but unfounded assumption that we now have a perfect working understanding of the physiological behaviour of the respiratory system in health and disease. Although it seems improbable that completely new disciplines within respiratory physiology will emerge with fundamentally different ways of describing the mechanical or gas exchanging function of the lung, advances in computing and new observations in disease have highlighted previously unsuspected physiological abnormalities that have changed the way we view lung disease and the interface between disordered lung mechanics, symptomatology and disability. This is especially true for the two related physiological concepts of expiratory flow limitation and dynamic hyperinflation, which are now being taken from the physiological laboratory to the bedside with dramatic effect. Each arises from well-established theoretical and practical observations first made 40 yrs ago and now adapted to a range of settings, particularly in the field of obstructive lung disease. This review focuses on how these conditions are defined and assessed and what evidence there is that they might be important in lung disease.

Airway Resistance↗
PubMed1996

Physiological and morphological determinants of maximal expiratory flow in chronic obstructive lung disease.

Maximal expiratory flow in chronic obstructive pulmonary disease (COPD) could be reduced by three different mechanisms; loss of lung elastic recoil, decreased airway conductance upstream of flow-limiting segments; and increased collapsibility of airways. We hypothesized that decreased upstream conductance would be related to inflammation and thickening of the airway walls, increased collapsibility would be related to decreased airway cartilage volume, and decreased collapsibility to inflammation and thickening of the airway walls. Lung tissue was obtained from 72 patients with different degrees of COPD, who were operated upon for a solitary peripheral lung lesion. Maximal flow-static recoil (MFSR) plots to estimate upstream resistance and airway collapsibility were derived in 59 patients from preoperatively measured maximal expiratory flow-volume and pressure-volume curves. In 341 transversely cut airway sections, airway size, airway wall dimensions and inflammatory changes were measured. Airflow obstruction correlated with lung elastic recoil and the MFSR estimate of airway conductance but not to airway collapsibility or to the amount of airway cartilage. The upstream conductance decreased as the inner wall became thicker. Airway collapsibility did not correlate with the amount of airway cartilage, inflammation, or airway wall thickness. We conclude that the maximal flow-static recoil model does not adequately reflect the collapsibility of the flow-limiting segment.

Adult↗
PubMed1992

Oscillatory mechanics of the respiratory system in neuromuscular disease.

Respiratory impedance measurements by means of the technique of forced oscillations together with spirometry and measurements of maximal mouth pressures were performed in 27 patients with a variety of neuromuscular disorders to assess the value of adding respiratory impedance measurements in the evaluation of lung function in neuromuscular disease. Using the technique of forced oscillations, impedance measurements are easily performed in physically disabled persons, since they require little active cooperation and no forced respiratory maneuvers. Normal respiratory impedance characteristics were found, although resistance values were somewhat higher than those found in normal subjects, signifying the absence of airflow limitation. Spirometric values were markedly reduced, as were maximal mouth pressures. No significant correlations were found between the forced expiratory volumes in 1 s (FEV1) and the impedance data. A strong curvilinear relationship was observed between Pemax and the RV/TLC ratio and a strong correlation existed between FEV1 and Premax. It is concluded from our study that forced oscillometry is a useful tool for the assessment or exclusion of airflow obstruction in patients with neuromuscular disorders when plethysmography is difficult to perform and forced expiratory flow-volume data reflect muscle weakness rather than airflow limitation.

Adolescent↗
PubMedDate not supplied

[Reference values of pulmonary compliance (author's transl)].

Pulmonary compliance has been measured, using a classical method in 156 healthy subjects aged between 18 and 74 years, breathing spontaneously. Pulmonary compliance (ml-cmH2O-1) was related to height in meters (H) by an allometric relationship such as C = aHb. As b was not significantly different from three, than C/H3 ratio was studied. This ratio was not dependent on age so that it was possible to establish that, in men, C (ml-cmH2O-1) = 36.6 H3 (m) and in women, C (ml-cmH2O-1) = 33.3 H3 (m). These two relationships were significantly different. From these relationships and from reference values of pulmonary volumes, specific pulmonary compliance could be calculated but since confidence limits were very wide, their utilization is limited. Furthermore, it is difficult to apply specific compliance in respiratory impairment.

Adolescent↗
PubMedDate not supplied

Postoperative changes on pulmonary function after laparoscopic and open cholecystectomy.

BACKGROUND/AIMS: We examined 28 patients who underwent cholecystectomy for acute or chronic cholecystitis and/or cholelithiasis in order to evaluate the effect of surgical technique on respiratory functional parameters. METHODOLOGY: We compared lung volume, flow parameters and blood gas indices in two groups of patients, eighteen of which underwent laparoscopic and ten of which open cholecystectomy, specifically on the 2nd and 8th postoperative day lung function indices were compared to preoperative values. The same anesthetic protocol was administered for all patients. No underlying illness other than the cholecystitis and/or cholelithiasis was present. RESULTS: From the results of lung volume parameters, ERV (%pred) data indicate a better expiratory ability for the Open Cholecystectomy [preop.: 93.10 (38.80), 8th day: 116.90 (63.69) compared to the Laparoscopic Cholecystectomy group (preop.: 105.39 (31.51), 8th day: 98.72 (35.80). For IC (%pred.) parameter, in the Open Cholecystectomy group a marked but not statistically significant decrease remained into the 8th day (preop.: 86.70 (16.40). 8th day: 68.40 (16.98)] whereas for the Laparoscopic Cholecystectomy group, IC %pred value reflected a better respiratory performance [preop.: 92.83 (17.87), 8th day: 82.50 (18.82)]. For RV and RV/TLC parameter measurements a marked increase in the %pred value was observed for the Laparoscopic Cholecystectomy group on the 8th postoperative day as compared to preoperative data [RV: 122.94 (42.80), 109.22 (33.23) respectively, RV/TLC: 122.68 (31.10), 109.14 (21.56) respectively]. From the analysis of the flow parameters, a distinct difference was evident for PEF between the preoperative and 8th postoperative day data with the Laparoscopic Cholecystectomy group showing statistically significant better flow rates [preop.: 93.72 (15.91), 8th day: 84.33 (20.67)] as compared to the Open Cholecystectomy group [preop.: 82.30 (22.98), 8th day: 59.10 (15.23)]. CONCLUSIONS: Having compared the 8th postoperative day with preoperative data for the two surgical methods, open cholecystectomy presented a better expiratory performance as compared to the laparoscopic method. However, laparoscopic cholecystectomy resulted in an overall better postoperative respiratory function.

Adult↗
PubMed1976

Physical signs in childhood asthma.

In 62 children with bronchial asthma, the presence of subjective dyspnea and wheeze, and some physical signs commonly associated with chronic obstructive airway disease in older patients, were compared with results of routine pulmonary function tests. Overall, airway resistance and the relationships of residual volume and functiona residual capacity to total lung capacity were increased and other measurements of pulmonary function were moderately decreased. The time-honored subjective dyspnea, wheeze, rhonchi, and prolonged expiration were least useful as indices of severity of disease. Most of the patients, particularly those in whom laboratory testing revealed marked impairment, had notable rhonchi, prolonged expiration, scalene muscle and sternocleidomastoid contraction, and supraclavicular indrawing. Only sternocleidomastoid contraction and supraclavicular indrawing clearly correlated with the severity of airway obstruction. A call is made for a search for these useful signs, whose presence may be the only clue to moderately severe disease; however, their absence does not guarantee absence of severe airway obstruction.

Adolescent↗
PubMed1976

Static mechanical lung properties in healthy children.

The elastic properties of the lung (elastic recoil and static compliance) have been studied in 27 children from 7 to 15 years of age by a quasi-static method. There is a significant relationship between the static expiratory compliance and the quasistatic pressures at different percentages of total lung capacity on the one hand, and height and age on the other. The specific compliance is independent of both height and age. The authors also use a sigmoid mathematical model based on the relationship between specific compliance and maximum pulmonary volume. This model fits well with the experimental data. Comparison is made with the currently used exponential model of Salazar & Knowles. The results favour the hypothesis of an increase in the number of alveoli all through childhood.

Adolescent↗
PubMed2006

Relationship between inspiratory muscle strength and cough capacity in cervical spinal cord injured patients.

STUDY DESIGN: Prospective single centre study. OBJECTIVES: Pulmonary rehabilitation focuses on improving the expiratory muscle function in order to increase the reduced cough capacity in patients with cervical spinal cord injuries (SCI). However, an improvement in the inspiratory function is also important for coughing effectively. Therefore, this study was to examine the significance of the inspiratory muscle strength on the cough capacity in the patients with a cervical SCI. SETTING: SCI unit, Yonsei Rehabilitation Hospital, Seoul, Korea. METHODS: The vital capacity (VC), maximum inspiratory pressure (MIP), and maximum expiratory pressure (MEP) were measured. Moreover, the unassisted peak cough flow (PCF) and assisted PCF under three conditions were evaluated. RESULTS: All three assisted cough methods showed a significantly higher value than the unassisted method (P < 0.001). The VC correlated with the voluntary cough capacity and the MIP (R = 0.749) correlated more significantly with the VC than the MEP (R = 0.438) (P < 0.01). The MIP showed a higher correlation with both the unassisted PCF and all three assisted PCFs than the MEP (P < 0.001). CONCLUSIONS: The management of the inspiratory muscle strength should be considered in the pulmonary rehabilitation at cervical SCI patients.

Adult↗
PubMedDate not supplied

Respiratory function in chronic hemiplegia.

Dynamic spirometry was examined in 23 non-smoking hemiplegic patients after the acute phase. The decrease of slow inspiratory forced capacity is related to motor impairment and does not vary with time. The forced inspiratory and expiratory vital capacities are similar to the slow inspiratory vital capacity in the first 6 months of the disease, but significantly decrease later independent of the motor impairment. The peak expiratory flow is highly variable but is clearly decreased, and is related to motor impairment. These results point to a restrictive respiratory syndrome due to mechanical limitation of thorax excursions caused by weakness, hypotonicity, and incoordination of the trunk musculature. The importance of long-term physiotherapy of the trunk is emphasized.

Adult↗
PubMed1997

Single-breath diffusing capacity of NO independent of inspiratory NO concentration in rabbits.

Pulmonary diffusing capacity of NO (DLNO) was determined by performing single-breath experiments on six anesthetized paralyzed supine rabbits, applying inspiratory concentrations of NO (FINO) within a range of 10 parts per million (ppm) < or = FINO < or = 800 ppm. Starting from residual volume, the rabbit lungs were inflated by 50 ml of a NO-nitrogen-containing indicator gas mixture. Breath-holding time was set at 0.1, 1, 3, 5, and 7 s. Alveolar partial pressure of NO was determined by analyzing the end-tidal portion from expirates, with the use of respiratory mass spectrometry. In the six animals, pulmonary diffusing capacity of NO averaged DLNO = 1.92 +/- 0.21 ml.mmHg-1.min-1 (mean +/- SD value). Despite extreme variations in FINO, we found very similar DLNO values, and in three rabbits we found identical values even at such different FINO levels of 80 ppm or 500, 20, or 200 ppm as well as 10 or 800 ppm. There was also no dependence of DLNO on the respective duration of the single-breath maneuvers. In addition, the time course of NO removal from alveolar space was independent of applied FINO levels. These results suggest that DLNO determinations are neither affected by chemical reactions of NO in alveolar gas phase as well as in lung tissue nor biased by endogenous release of NO from pulmonary tissue. It is our conclusion that the single-breath diffusing capacity of NO is able to provide a measure of alveolar-capillary gas conductance that is not influenced by the biochemical reactions of NO.

Administration, Inhalation↗
PubMed1983

Nonorganic upper airway obstruction.

Two cases of severe dyspnea and stridor with upper airway obstruction of obscure origin are discussed. Complete medical evaluation could identify no organic cause for the symptoms, and functional upper airway obstruction was diagnosed. Treatment with psychotherapy and relaxation techniques was successful. Diagnosis can be made with pulmonary function studies. Flow-volume loops may show a lower inspiratory vital capacity than expiratory vital capacity and a discrepancy between inspiratory flow limitation and airway resistance. It is important to establish a functional etiology to prevent unnecessary treatment and provide proper care.

Adolescent↗