Pulmonary function and maximal transrespiratory pressures in ankylosing spondylitis

Assessment Tools for Pulmonary Involvement in Patients with Ankylosing Spondylitis: Is Diaphragmatic Ultrasonography Correlated to Spirometry?

Objective

Spondyloarthritis (SpA) is a chronic inflammatory rheumatic disease that can lead to spinal ankylosis and consequently, restrictive pulmonary dysfunction. Thus, the present study aimed to assess the accuracy of diaphragm ultrasound compared to spirometry in the screening of restrictive pulmonary disorders in radiographic SpA patients.

Methods

We conducted a cross-sectional study of 50 patients with radiographic SpA, over six months. Sociodemographic data, clinical characteristics of the disease, as well as biological, radiological, and therapeutic data, were collected. Spirometry and diaphragm ultrasound were performed.

Results

The mean age of the study participants (N= 50) was 42.7±11 years [range: 25-66] with male predominance (N= 41). Spirometry showed a restrictive disorder in 32% of cases. The mean chest expansion (CE) value was 3.9±1.81cm [range: 1-9] with a median of 4 cm. A pathological value (<5cm) was observed in 72% of cases. A significant positive correlation was found between the right inspiratory diaphragmatic thickness and forced vital capacity (FVC) (r= 0.36; p = 0.02) and the supine FVC (r=0.29; p = 0.04). The left inspiratory diaphragmatic thickness was correlated with the percentage of the FVC decrease (r= 0.35; p = 0.01) defined as the percentage of difference between FVC and supine FVC. The right expiratory diaphragmatic thickness was associated with the FVC (r=0.32; p = 0.02). A significant positive correlation was found between the CE and the presence of B lines (r=0.32; p = 0.02), but not between the CE and the FVC.

Conclusion

The present study showed that diaphragm ultrasonography is correlated with spirometric findings in radiographic SpA patients. Further studies are required to assess its reliability, specificity, and sensitivity in this pathology.

Investigation of the effectiveness of aerobic exercise training in individuals with ankylosing spondylitis: Randomized controlled study

OBJECTIVE

To investigate the effect of the addition of aerobic training to spinal mobility exercises on disease-specific outcomes and functional exercise capacity, aerobic capacity and respiratory muscle strength of ankylosing spondylitis (AS) patients.

METHODS

The study included 31 volunteers (mean age: 44.90 ± 11.52 years) diagnosed with AS. The demographic characteristics and disease-related data of all subjects were recorded, then, the Bath AS Disease Activity Index (BASDAI), Bath AS Metrology Index (BASMI) and Bath AS Disease Function Index (BASFI), the 6-minute walk test, the Bruce Treadmill Test and spirometry were used, respectively. The intervention group attended a 12-week program of aerobic exercise sessions, plus supervised spinal mobility exercises, 3 days a week. The control group performed the supervised spinal mobility exercises only, 3 times a week, for 12 weeks.

RESULTS

There was a significant improvement in BASDAI (p = .002), BASMI (p = .021), 6 DYT (p = .036), VO₂ max (p = .000), MIP (p = .005) and MEP (p = .022) results in the intervention group after 12 weeks of training. In the comparisons of the pre-treatment and post-treatment differences, BASDAI (p = .032) decreased and VO₂ (p = .001) max increased, showing significant improvements in the intervention group and these values were maintained.

CONCLUSION

It is striking that improvements in all parameters except BASFI were achieved in the aerobic training group. These results demonstrate that an aerobic exercise program should be included in an individual exercise prescription for the management of AS.

Disorders of the Chest Wall: Clinical Manifestations

Chest wall disorders represent deformities and/or injuries that alter the rib cage geometry and result in pulmonary restriction, increased work of breathing, exercise limitations, and cosmotic concerns. These disorders are congenital or acquired and affect all ages. Disorders affecting the spine (kyphoscoliosis, ankylosing spondylitis), ribs (flail chest), and sternum (pectus excavatum) are discussed in this article, with emphasis on clinical presentations, pulmonary function abnormalities, diagnosis, and treatment.

Can ultrasound be an assessment tool for sagittal spine mobility and chest expansion in patients with ankylosing spondylitis?

We aimed to examine whether ultrasound (US) is useful for evaluating spinal mobility and chest expansion in ankylosing spondylitis (AS) patients and determine a cutoff value to identify reduced sagittal lumbar mobility.Our cross-sectional study included 50 AS patients and 50 controls. Metric measurements and Bath AS indices were measured in AS patients. The distance between C6-C7, T11-T12, and L4-L5 vertebrae was measured, and the difference and percentage of difference between erect position and maximal cervical and lumbar flexion was calculated (T11-T12dif, T11-T12%, L4-L5dif, L4-L5%, T+L dif, T+L%). Intercostal divergence was measured 1.5 cm away on the left from the sternocostal space during maximum inhalation and maximum exhalation, and the difference and percentage of difference between them was calculated (ICdif, IC%).All metric measurements were lower in the AS group except for tragus-to-wall distance. T11-T12dif, T11-T12%, L4-L5dif, T+L dif, and T+L% values were higher in the control group, while other US measurements did not differ between the groups. All US measurements except ICdif and IC% correlated with the Bath AS Metrology Index.Thus, US may be used for assessing spinal mobility in patients with AS. T11-T12dif <0.79 cm may show decreased lumbar sagittal mobility.

The effect of inspiratory muscle training on respiratory variables in a patient with ankylosing spondylitis: A case report

Ankylosing Spondylitis (AS) presents with both musculoskeletal and cardiorespiratory pathophysiological manifestations. Inspiratory muscle training (IMT) may be a useful intervention to address deficits in respiratory and functional status.

CASE DESCRIPTION

A 25-year-old male with AS initially sought treatment for low back and right hip pain, but 7 weeks of IMT was also provided due to abnormal respiratory performance.

OUTCOMES

At baseline, the patient presented with a resting respiratory rate (RR) of 14.5 breaths/minute, tidal volume (TV) of 0.76 L, minute ventilation (VE) of 10.87 L/min, and end tidal CO2 (PetCO2) of 30.56 mmHg. Baseline exercise test results revealed a VO2max of 44 ml/kg/min and VE to CO2 output (VE/VCO2) slope of 30. Baseline MIP, SMIP, and MEP were 54 cm H2O, 507 PTU, and 87 cm H2O, respectively, and increased to 176 cm H2O, 807 PTU, and 151 cm H2O, respectively, after IMT. The VO2max increased to 51 ml/kg/min with decreases in the VE/VCO2 slope (29), resting RR (12 breaths/minute), resting TV (0.52 L), and resting VE (6.83 L/min) after IMT. Improvements during postural challenges were also observed.

DISCUSSION

This case demonstrates the clinical utility of respiratory gas analysis and respiratory performance measures to identify functional deficits and manage a patient with AS. The improvements in respiratory performance at rest, during postural challenges, and during maximal exercise after a relatively short period of IMT highlights the role IMT may have to improve functional status in patients with AS. Further investigation of IMT in patients with AS is warranted.

Unusual Respiratory Manifestations of Ankylosing Spondylitis – A Case Report

A male patient, 54 years old, was initially admitted to the hospital because of fatigue he felt during the last month and swelling of the lower legs. Upon hospital admittance, gas exchange analysis showed global respiratory failure: pO2=6.1 kPa, pCO2=10.9 kPa, pH=7.35, A-a gradient = 1.0. Due to the existence of hypercapnia and decompensated respiratory acidosis, the patient was connected to a device for non-invasive mechanical ventilation. Reduced chest mobility was noticed, and the respiratory index value was decreased. Radiographs of the chest and thoracic and lumbo-sacral spine showed marked changes on the spine attributable to ankylosing spondylitis (AS). Radiographs of the sacroiliac joints showed reduced sacroiliac joint intraarticular space with signs of subchondral sclerosis. The diagnosis of AS was set on the basis of New York Criteria (bilateral sacroiliitis, grade 3) and clinical criteria (back pain, lumbar spine limitation and chest expansion limitation). HLA typing (HLA B27 +) confirmed the diagnosis of AS. Pulmonary function test proved severe restrictive syndrome. Polysomnography verified the existence of severe obstructive sleep apnoea (AHI =73). This was a patient with newly diagnosed AS, with consequent severe restrictive syndrome and global respiratory failure with severe obstructive sleep apnoea. Thee patient was discharged from the hospital with a NIV (global respiratory failure) device for home use during the night.

Differences in cardiovascular manifestations between ankylosing spondylitis patients with and without kyphosis

The objective of this study is to evaluate the differences in cardiovascular manifestations between ankylosing spondylitis (AS) patients with and without kyphosis. A retrospective review of consecutive AS patients treated at our hospital between June 2013 and June 2015 was performed. There were 122 patients who met all of the inclusion and exclusion criteria. Among these patients, there were 57 (ASK group) patients with global kyphosis (GK) > 40° and 65 (AS group) patients with GK < 40°. General information, C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), electrocardiography, and echocardiography were record. ESR and CRP levels in the ASK group were significantly higher than the AS group (P < 0.05). Fifteen patients in ASK group but 3 patients in AS group suffered from a left ventricular high voltage (P < 0.05). Heart rate in ASK group was 83.91 ± 13.68 beats/min, and it was 73.88 ± 13.04 beats/min in AS group (P < 0.05). The E/A ratio was 1.13 ± 0.38 in ASK group and 1.32 ± 0.49 in AS group (P < 0.05). The mitral E-wave deceleration time and isovolumetric relaxation time were, respectively, 236.25 ± 34.26 ms and 101.86 ± 17.57 ms in ASK group, which were shorter in AS group (P < 0.05). This study showed that AS patients with kyphosis had a statistically increased incidence of cardiovascular complications including a more rapid heart rate, left ventricular high voltage, and left ventricular diastolic dysfunction.

Changes in cardiac function after pedicle subtraction osteotomy in patients with a kyphosis due to ankylosing spondylitis

Cardiac disease in patients with ankylosing spondylitis (AS) has previously been studied but not in patients with a kyphosis or in those who have undergone an operation to correct it.

The aim of this study was to measure the post-operative changes in cardiac function of patients with an AS kyphosis after pedicle subtraction osteotomy (PSO).

The original cohort consisted of 39 patients (33 men, six women). Of these, four patients (two men, two women) were lost to follow-up leaving 35 patients (31 men, four women) to study. The mean age of the remaining patients was 37.4 years (22.3 to 47.8) and their mean duration of AS was 17.0 years (4.6 to 26.4). Echocardiographic measurements, resting heart rate (RHR), physical function score (PFS), and full-length standing spinal radiographs were obtained before surgery and at the two-year follow-up.

The mean pre-operative RHR was 80.2 bpm (60.6 to 112.3) which dropped to a mean of 73.7 bpm (60.7 to 90.6) at the two-year follow-up (p = 0.0000). Of 15 patients with normal ventricular function pre-operatively, two developed mild left ventricular diastolic dysfunction (LVDD) at the two-year follow-up. Of 20 patients with mild LVDD pre-operatively only five had this post-operatively. Overall, 15 patients had normal LV diastolic function before their operation and 28 patients had normal LV function at the two-year follow-up.

The clinical improvement was 15 out of 20 (75.0%): cardiac function in patients with AS whose kyphosis was treated by PSO was significantly improved.

Cite this article: Bone Joint J 2015;97-B:1405–10.

Pulmonary function improvement in patients with ankylosing spondylitis kyphosis after pedicle subtraction osteotomy

STUDY DESIGN

A prospective clinical study.

OBJECTIVE

To observe postoperative change in pulmonary function in patients with ankylosing spondylitis (AS) kyphosis after pedicle subtraction osteotomy (PSO).

SUMMARY OF BACKGROUND DATA

The preoperative pulmonary dysfunction in patients with AS has been reported in several literatures, whereas few research about postoperative changes in pulmonary function with AS kyphosis was published.

METHODS

A total of 32 (27 males and 5 females) patients with AS were eligibly involved. Twenty-nine (25 males and 4 females) patients completed the follow-up and 3 (2 males and 1 females) patients were lost. Pulmonary function tests, breath-holding time (BHT), and full-length spine radiographs in natural standing position were followed postoperatively.

RESULTS

The global kyphosis significantly decreased from 63.0°± 20.3° preoperatively to 15.3°± 10.3° postoperatively and 17.1°± 10.9° at the 2-year follow-up. The BHT before surgery was 32.5 ± 10.1 s, whereas the postoperative BHT had increased to 43.1 ± 8.6 s (P < 0.05). Two patients with AS underwent normal pulmonary function test before operation, whereas there were 19 patients at 2-year follow-up. The clinical improvement rate was 85.2% (23/27). The percent-predicted vital capacity had increased from 68.4% ± 9.5% to 79.4% ± 6.1% at 2-year follow-up (P < 0.05). The percent-predicted forced vital capacity before PSO was 75.5% ± 6.4% and it was 81.0% ± 6.9% at 2-year follow-up (P < 0.05). The improved percent-predicted vital capacity and predicted forced vital capacity had a positive correlation with the correction of global kyphosis (r = 0.6328 and 0.8612, respectively).

CONCLUSION

The postoperative pulmonary function including pulmonary volume and ventilatory function in patients with AS with kyphosis had significantly improved at 2-year follow-up. And, the improved pulmonary function had a positive correlation with the kyphosis correction.

LEVEL OF EVIDENCE

3.

Restrictive pulmonary function is more prevalent in patients with ankylosing spondylitis than in matched population controls and is associated with impaired spinal mobility: a comparative study

INTRODUCTION

Pulmonary involvement is a known manifestation in patients with ankylosing spondylitis (AS). However, previous studies have been based on small samples and the reported prevalence and associations with typical clinical features vary. The purpose of this study was to compare pulmonary function (PF) in patients with AS and population controls, and to study associations between PF and disease related variables, cardio-respiratory fitness and demographic variables in patients with AS.

METHODS

In a cross-sectional controlled study, 147 AS patients and 121 controls underwent examinations, including demographic variables, laboratory (C-reactive protein (CRP), erythrocyte sedimentation rate (ESR)) and clinical measures (disease activity (AS disease activity score, ASDAS), physical function (Bath ankylosing spondylitis functional index, BASFI), spinal mobility (Bath ankylosing spondylitis metrology index, BASMI), chest expansion, cardio-respiratory fitness (peak oxygen uptake, VO(2peak) and pulmonary function test (PFT) (spirometry)). Cumulative probability plots were used to visualize associations between the ASDAS and BASMI scores and the corresponding forced vital capacity (FVC%, percentage of predicted value controlled for the influence of confounding factors) score for each patient. Univariate ANCOVAs were performed to explore group differences in PF adjusting for relevant variables, and a multiple regression model was used to estimate the explanatory power of independent variables (demographic, disease related, VO(2peak) on restrictive ventilatory impairment (FVC%).

RESULTS

AS patients showed significantly lower PF values compared with controls, and significantly more patients were categorized with restrictive pattern (18% vs. 0%, P < 0.001). Cumulative probability plots showed significant associations between spinal mobility measures (BASMI) and FVC% for individual patients. BASMI, chest expansion and male gender contributed significantly and independently in a multiple regression model predicting the variation of FVC% in AS patients, whereas disease activity, physical function and VO(2peak) did not contribute significantly. The final model explained 45% of the variance in FVC% (P < 0.001).

CONCLUSIONS

This study showed significantly impaired pulmonary function in the AS patients compared to controls and reference data, and demonstrated a clear relationship between reduced spinal mobility and restrictive PF in AS patients. The results support the assumption of an association between musculoskeletal limitations and restrictive respiratory impairment in AS, emphasizing the importance of maintaining spinal flexibility in the management of the disease. Further, patients with severely reduced spinal mobility should be referred for pulmonary function examination and relevant follow-up treatment.

Hypoventilation syndromes

The hypoventilation syndromes represent a variety of disorders that affect central ventilatory control, respiratory mechanics, or both. Obesity hypoventilation syndrome is a clinically important disorder with serious cardiovascular and metabolic consequences if unrecognized. Hypoventilation in asthma and COPD is caused by mechanical challenges imparted by airflow obstruction and increase in dead space. In neuromuscular disease, respiratory muscle weakness results in hypoventilation. Decreases in thoracic volume and limited expansion of the chest highlight the restrictive ventilatory impairments seen in hypoventilation associated with chest wall disorders. Despite the mechanism, effective hypoventilation treatment targets the underlying disease and use of noninvasive ventilation.

Pulmonary manifestations of ankylosing spondylitis

Ankylosing spondylitis, a chronic multisystem inflammatory disorder, can present with articular and extra-articular features. It can affect the tracheobronchial tree and the lung parenchyma, and respiratory complications include chest wall restriction, apical fibrobullous disease with or without secondary pulmonary superinfection, spontaneous pneumothorax, and obstructive sleep apnea. Ankylosing spondylitis is a common cause of pulmonary apical fibrocystic disease; early involvement may be unilateral or asymmetrical, but most cases eventually consist of bilateral apical fibrobullous lesions, many of which are progressive with coalescence of the nodules, formation of cysts and cavities, fibrosis, and bronchiectasis. Mycobacterial or fungal superinfection of the upper lobe cysts and cavities occurs commonly. Aspergillus fumigatus is the most common pathogen isolated, followed by various species of mycobacteria. Prognosis of patients with fibrobullous apical lesions is mainly determined by the presence, extent, and severity of superinfection. Pulmonary function test results are nonspecific and generally parallel the severity of parenchymal involvement. A restrictive ventilatory impairment can develop in patients with ankylosing spondylitis because of either fusion of the costovertebral joints and ankylosis of the thoracic spine or anterior chest wall involvement. Chest radiographic findings may mirror the severity of clinical involvement. Pulmonary parenchymal disease is typically progressive, and cyst formation, cavitation, and fibrosis are seen in advanced cases. No treatment has been shown to alter the clinical course of apical fibrobullous disease. Although several antiinflammatory agents, such as infliximab, etanercept, and adalimumab, are being used to treat ankylosing spondylitis, their effects on pulmonary manifestations are unclear.

Pulmonary abnormalities on high-resolution computed tomography in ankylosing spondylitis: relationship to disease duration and pulmonary function testing

The aim of this study was to identify the pulmonary abnormalities on high-resolution computed tomography (HRCT) in patients with ankylosing spondylitis (AS) and to examine the relationship with the duration of disease and pulmonary function test (PFT) results. Twenty male AS patients with a mean age of 37.1 ± 9.4 years were enrolled in this study. The patients were assigned into 2 groups according to disease duration: patients with disease duration <10 years (n = 10) and ≥ 10 years (n = 10). All patients underwent clinical examination, PFT and HRCT. HRCT revealed abnormalities in 14 patients (70%). The most common findings were apical fibrosis (45%) and emphysema (25%). HRCT findings were more prominent in late AS patients (disease duration ≥ 10 years) (P = 0.015). PFT were considered as abnormal in 4 patients (20%). While 3 patients had a restrictive type pulmonary deficiency, one patient had a mild obstructive pattern. Three of these patients had concomitant HRCT abnormalities. On the other hand, 10 patients with normal PFT had abnormalities on HRCT. These findings suggest that pulmonary involvement in AS patients without respiratory symptoms could be sensitively detected by HRCT. However, the clinical significance of these radiological abnormalities should be examined in further prospective studies.

Diaphragmatic movements in ankylosing spondylitis patients and their association with clinical factors: an ultrasonographic study

We compared diaphragmatic motion between ankylosing spondylitis (AS) patients and controls, as assessed by the ultrasonographic method. We included 33 consecutive AS patients (19 males, 14 females) followed up at our center and 14 apparently healthy controls (8 males, 6 females) into our study. AS patients fulfilled the modified New York classification criteria for AS. Patients' demographic and clinical data, functional parameters, and radiographic findings were recorded down. By evaluating the motion of right and left diaphragm during deep expirium and inspirium, the mean diaphragmatic motion was determined by ultrasonography. Diaphragmatic motion in AS patients was less than in controls, but the difference was not significant (68.9 ± 17 mm vs. 77.8 ± 22.4 mm, P = 0.14). Diaphragmatic motion in AS patients who were active according to BASDAI score (>4) was not different from inactive patients (70.4 ± 20.5 vs. 67.5 ± 13.5, P > 0.05). The mean diaphragmatic motion had a positive correlation with occiput-to-wall distance (r = 0.35, P = 0.048); and negative correlations with cervical rotation (r = -0.45, P = 0.01) and modified Schober test (r = -0.34, P = 0.05) in AS patients. We did not detect any association of mean diaphragmatic motion with thoracic expansion on deep expiration. Diaphragmatic motion in AS does not differ significantly from the control group. Factors like disease activation, chest expansion, and the severity of radiographic findings do not affect diaphragmatic motion. There is no compensatory increase in diaphragmatic motion in AS.

The pulmonary involvement in rheumatic diseases: pulmonary effects of ankylosing spondylitis and its impact on functionality and quality of life

Rheumatic diseases are chronic inflammatory diseases which cause mild to severe functional loss and disability due to articular and extra-articular manifestations. One common form -ankylosing spondylitis (AS)- affects mainly the axial skeleton and sacroiliac joints, and certain extra-articular organs. The pulmonary involvement is a known manifestation of AS and emerges either in the form of interstitial lung disease or in the form of restricted pulmonary functions. The aim of this study is to determine the pulmonary functions in AS patients and to assess its relationship with quality of life, functionality and disease activity. Thirty-six AS patients and 34 healthy volunteers were recruited for the study. A detailed examination, pulmonary function tests, smoking inquiry and quality of life questionnaire were performed on all participants. Also patients were requested to complete functionality and disease activity indexes. The outcomes showed that 15 (41.7%) AS patients had pulmonary involvement: twelve patients with restrictive patterns, one with obstructive pattern, and two with both restrictive and obstructive patterns. Decreased forced expiratory volume in one second was associated with deteriorated functionality (p < 0.05). Decreased chest expansion was also accompanied with decreased forced vital capacity (p < 0.05). There was no statistically significant difference between the smoking and non-smoking patients in regard to disease activity, functionality and pulmonary function test variables (p > 0.05). In conclusion, the pulmonary involvement is common in AS and might have disturbed functionality and the quality of life in AS patients.

[A comparison of respiratory muscle strength, pulmonary function tests and endurance in patients with early and late stage ankylosing spodylitis]

BACKGROUND

Ankylosing spondylitis (AS) is a multisystemic disease in which pulmonary function is altered owing mainly to the restriction of chest wall involvement. A restrictive ventilatory defect has been extensively reported. This has been suggested to be a consequence of reduced mobility of the thoracic cage. Respiratory function in AS shows a typical restrictive pattern but pulmonary compliance, diffusion capacity, and arterial blood gases are normal.

OBJECTIVE

The objective of the present study was to compare pulmonary function tests (PFT), respiratory muscle strength (MIP, MEP) and endurance (MVV) in early and late AS.

METHODS

A total of 35 patients (30 males, 5 females) took part, all of whom met the New York criteria for AS. Patients were divided into two groups for the comparison of early (disease duration <10 years, 20 patients) and late (disease duration >10 years, 15 patients) manifestations in pulmonary function tests, respiratory muscle strength and endurance, dyspnea score, chest expansion, and BASFI score. In addition, 21 healthy controls were compared with the AS patients. Measurement of chest expansion was performed in all subjects. Pulmonary function tests were performed by spirometry. Respiratory muscle strength was evaluated by a mouth pressure meter (MPM). Functional status was assessed by BASFI in all AS patients.

RESULTS

There was no significant difference in body mass index between the groups. The FVC and FEV(1) were significantly lower in late AS (p=0.003, p=0.03, restrictive ventilatory defect ). Chest expansion was significantly lower in late AS (p<0.05). There was no significant difference for MIP or MEP values between late AS, early AS and the controls (p>0.05). Endurance (MVV) was significantly lower in late AS patients (p=0.05). Although the BASFI and dyspnea scores were higher in late AS, they did not reach significant levels. In addition, age was negatively correlated with MIP and MEP in late AS (r=-0.733; p=0.02, r=-0.667; p=0.05).

CONCLUSION

This study demonstrates that FVC and FEV(1) (hallmarks of a restrictive pattern), MVV (endurance) and chest expansion are especially involved in long-standing AS. Therefore, improvement of the thoracic cage should be taken into consideration, especially in early AS. These patients should be encouraged to make regular respiratory exercises for preventing the limitation of chest expansion and also improving cardiopulmonary fitness and respiratory endurance.

Pulmonary involvement in ankylosing spondylitis

This is a prospective study analyzing 52 asymptomatic, consecutive patients with ankylosing spondylitis (AS), who submitted to a pulmonary investigation that included plain chest radiography, pulmonary function test (PFT), and thoracic high-resolution computed tomography (HRCT). The results were compared according to sex, race, dorsal spine involvement, thoracic diameter, smoking status, and HLA-B27. There were four patients (8%) with an altered plain chest radiograph. PFT presented a restrictive pattern in 52% of the patients. Thoracic HRCT showed abnormalities in 21 patients (40%), predominantly nonspecific linear parenchymal opacities (19%), lymphadenopathy (12%), emphysema (10%), bronchiectasis (8%), and pleural involvement (8%). Linear parenchymal opacities were associated with a smoking history (p=0.026) and dorsal spine involvement (p=0.032). HLA-B27 was not associated with any abnormality. A lower thoracic diameter was observed in patients with dorsal spine involvement (p=0.0001), restrictive pattern at PFT (p=0.023), and linear parenchymal opacities (p=0.015). The study concluded that nonspecific subclinical pulmonary involvement is frequent in AS.

Evaluation of pulmonary function and quality of life in women with osteoporosis

Osteoporotic vertebral fractures generally result in an increased kyphotic angle, which in turn may lead to disturbances in pulmonary function. The objective of the present study was to evaluate pulmonary function and quality of life in a group of osteoporotic patients. Fifteen women with osteoporosis and thoracic vertebral fractures (group 1), 20 women with osteoporosis without vertebral fracture (group 2) and 20 control women (group 3) were submitted to spirometry using a Vitatrace-130 SL spirometer and to an SF-36 quality of life questionnaire. Women with osteoporosis and vertebral fractures showed an increased kyphotic angle (median=60 degrees) and decreased forced vital capacity (group 1 vs. group 2, P =0.020; group 1 vs. group 3, P =0.039) and forced expiratory volume in 1 s (group 1 vs. group 2, P =0.008; group 1 vs. group 3, P =0.014) when compared with women without vertebral fractures or osteoporosis. A negative correlation was observed between thoracic kyphosis and the predicted value of expiratory forced volume in 1 s ( r =-0.713, P =0.003). No differences in the quality of life were detected between the three groups studied. We conclude that women with thoracic vertebral fractures have an increased kyphotic angle and present a decrease in lung volume.

Comparison of early and late pleuropulmonary findings of ankylosing spondylitis by high-resolution computed tomography and effects on patients' daily life

Ankylosing spondylitis (AS) is a multisystemic disease and extra-articular features may develop as pleuropulmonary involvement. We aimed to show and compare the early and late pleuropulmonary findings of AS and its effects on patients' daily life by causing dyspnea. The study consisted of 38 patients (33 male, 5 female). All patients met the New York criteria for AS. Patients were divided into two groups for comparison of early (disease duration <10 years and normal chest X-ray, 18 patients) and late (disease duration >/=10 years and normal or abnormal chest X-ray, 20 patients) manifestations. All patients underwent high-resolution computed tomography (HRCT) and pulmonary function tests. A questionnaire was completed to measure perceived shortness of breath (dyspnea score) with activities of daily living such as dressing, shaving or walking. HRCT findings were abnormal in 27 of the 38 patients (73%). Pulmonary involvement was high in early AS (61.1%). The number of findings in early and late AS found were as follows: mosaic pattern (9/10), parenchymal micronodules (2/3), parenchymal bands (5/9), bronchial wall thickening (2/10), ground-glass opacity (7/7), and interlobular septal thickening (6/10). A moderate correlation was obtained between presence of mosaic pattern and forced midexpiratory flow rate (FEF(25-75)) values indicating small airway obstruction (r=0.346, p=0.019). The dyspnea score was statistically higher in patients with AS having pulmonary involvement than those without involvement. Pulmonary involvement is common in early AS compared to late AS. The involvement of small airways was found frequently as interstitial lung disease in early and late AS. This study also suggests that AS with pulmonary involvement may affect patients' daily life by causing dyspnea, which is why early detection of pulmonary lesions may have clinical importance and should be studied in a large cohort.

Respiratory muscle performance as a possible determinant of exercise capacity in patients with ankylosing spondylitis

Reduction of exercise capacity in patients with ankylosing spondylitis is associated with skeletal muscle performance. The contribution of respiratory muscle performance is questionable. This pilot study was designed to investigate the relationship between respiratory muscle performance and exercise capacity in ankylosing spondylitis. Subjects were 12 patients with ankylosing spondylitis. Measurements of maximal respiratory pressures and inspiratory muscle endurance were performed and correlated with maximal exercise capacity. Lung function and chest wall expansion were reduced on average. Maximal inspiratory and expiratory pressures were reduced to 82 +/- 20% of predicted values and 75 +/- 22% of predicted values respectively. On average there was no reduction in inspiratory muscle endurance which remained at 103 +/- 36% of predicted values. No overall reduction was found in maximal exercise capacity, either expressed as maximal workload or as peak oxygen uptake; however, a wide range was found. Maximal workload and peak oxygen uptake correlated significantly with maximal respiratory pressures and respiratory muscle endurance. The best regression model for explaining the total variation of maximal workload and peak oxygen uptake selected maximal inspiratory pressures as the independent variable (r(2) = 59.6%, p = 0.003 and r(2) = 62.5%, p = 0.05 respectively.) These data suggest respiratory pressure and respiratory muscle endurance, in particular maximal inspiratory pressure, may be determinants of exercise capacity in patients with ankylosing spondylitis.

Respiratory muscle strength but not BASFI score relates to diminished chest expansion in ankylosing spondylitis

Pulmonary function is altered in ankylosing spondylitis (AS) owing mainly to the restriction of chest wall involvement (limited chest expansion). The objective of this study was to investigate the relationship between chest expansion, respiratory muscle strength (MIP, MEP) maximum voluntary ventilation (MVV), and BASFI score in patients with AS. Twenty-three male patients with definite AS and 21 age-matched healthy male controls were recruited for the study. Patients with AS were assessed for functional status by BASFI. Measurement of chest expansion and lumbar spinal flexion (modified Schober) method was performed in all subjects. Pulmonary function tests were performed by spirometry. Respiratory muscle strength was evaluated by a mouth-pressure meter (MPM). Body mass index (kg/m(2)) was recorded in all individuals. Chest expansion and modified Schober measurement were significantly lower in AS patients (p<0.05). Pulmonary function tests revealed restrictive lung disease. The mean BASFI score suggested good functional capacity in the AS group. The respiratory muscle strength and MVV were also lower in AS (p<0.05). The chest expansion was correlated with MIP and MEP values (r=0.491; p=0.02, r=0.436; p=0.05). Chest expansion was also correlated negatively with disease duration (r=-0.502; p=0.03). In addition, there was no correlation between chest expansion and BASFI score (r=-0.076; p=0.773). This study demonstrates that functional status (BASFI) is not influenced by the limitation of chest wall movement. It may be as a result of the maintenance of moderate physical activity during active life in patients with AS.

Lung findings on high resolution CT in early ankylosing spondylitis

OBJECTIVE

Ankylosing spondylitis (AS) is a chronic inflammatory disease mainly affecting the axial skeleton and pulmonary involvement is a well known feature of the disease. The aim of this study was to investigate the pulmonary high resolution computed tomography (HRCT) findings of patients with early AS. The relationship between pulmonary function tests (PFT) and HRCT findings was also determined.

SUBJECTS AND METHODS

Twenty-eight patients with AS (mean age 30.8+/-7.4 and disease duration 7.0+/-2.6) were included in the study. Patients with a disease duration of >10 years or had other pulmonary diseases were excluded. All patients underwent plain chest radiography (posteroanterior and lateral views), thoracic HRCT and PFT.

RESULTS

All chest radiographs were normal and HRCT revealed abnormalities in 18 patients. The most common abnormalities seen on HRCT were mosaic pattern (ten of 28), subpleural nodule (seven of 28) and parenchymal bands (five of 28). Seven of ten patients with mosaic pattern revealed air trapping areas on end expiratory scans. Twelve patients had abnormal PFT and all had restrictive type of involvement. Ten of these 12 patients had abnormal HRCT and the remaining two patients had normal HRCT. On the other hand, eight patients with normal PFT had abnormalities on HRCT.

CONCLUSION

Patients with early AS frequently have abnormalities on HRCT, even though they have normal PFT and chest X-ray. Small airway involvement was found as frequent as interstitial lung disease in early AS.

Disorders of the respiratory muscles

The act of breathing depends on coordinated activity of the respiratory muscles to generate subatmospheric pressure. This action is compromised by disease states affecting anatomical sites ranging from the cerebral cortex to the alveolar sac. Weakness of the respiratory muscles can dominate the clinical manifestations in the later stages of several primary neurologic and neuromuscular disorders in a manner unique to each disease state. Structural abnormalities of the thoracic cage, such as scoliosis or flail chest, interfere with the action of the respiratory muscles-again in a manner unique to each disease state. The hyperinflation that accompanies diseases of the airways interferes with the ability of the respiratory muscles to generate subatmospheric pressure and it increases the load on the respiratory muscles. Impaired respiratory muscle function is the most severe consequence of several newly described syndromes affecting critically ill patients. Research on the respiratory muscles embraces techniques of molecular biology, integrative physiology, and controlled clinical trials. A detailed understanding of disease states affecting the respiratory muscles is necessary for every physician who practices pulmonary medicine or critical care medicine.

Pulmonary manifestations of ankylosing spondylitis and relapsing polychondritis

Ankylosing spondylitis is a chronic inflammatory disease that affects chiefly the joints of the axial skeleton. It is a multisystem disease. Several extra-auricular manifestations of ankylosing spondylitis have been described including ocular, cardiovascular, renal, and neurologic complications. Pulmonary involvement consists principally of upper lobe fibrocystic changes and chest wall restriction. Relapsing polychondritis, on the other hand, is a rare disorder characterized by progressive inflammation and degeneration of the cartilaginous structures and other connective tissues throughout the body. Involvement of the respiratory tract is identified in more than one-half of patients with relapsing polychondritis.

Ankylosing spondylitis

Ankylosing spondylitis is an inflammatory disease involving entheses and joints, especially those in and around the spine. The most widespread involvement of the respiratory system by this disease occurs when this pathological process gives rise to chest wall pain, diminished chest wall movement and a dorsal stoop. As healing of the inflammatory process takes place, calcification occurs which leads to rigidity of these structures, with consequent loss of chest expansion which is exacerbated by the increasingly kyphotic spinal posture and intercostal muscle inefficiency. Fortunately diaphragmatic function is unimpaired and compensates well, so that there are only minor restrictive changes found in tests of respiratory function. Treatment is by mobilizing physiotherapy coupled with a home exercise programme encouraging mobility and improved cardiovascular fitness. As with many physical treatment methods, good quality controlled studies of efficacy are rare. The role of medication is to ease symptoms and hence enable exercise. Apical fibrobullous lung disease is found in a small proportion of AS patients. The initial changes are mainly fibrotic, with bullae becoming more important as the condition progresses. The disease may progress to major cavitation, which is prone to infection, especially with aspergillae. No methods exist which can either prevent the development of fibrobullous disease or halt its progression, although this may happen spontaneously. The main effects of therapy are aimed at the diagnosis and treatment of superinfection. Treatment of established aspergillosis, especially when aspergilloma formation has taken place, is unsatisfactory and carries substantial risks of morbidity and death. Non-apical pleural involvement, including pleural effusion, is very rare. The most common cause of breathlessness in AS patients is cardiac involvement by the disease.