Survival of patients with severe thoracic spine deformities receiving domiciliary oxygen therapy

Magnetic Resonance Imaging-Based Morphological Change of Paraspinal Muscles in Girls With Adolescent Idiopathic Scoliosis

STUDY DESIGN

A cross-sectional study.

OBJECTIVE

To investigate and compare any morphological differences in paraspinal muscles (PSM) between adolescent idiopathic scoliosis (AIS) patients (with severe or non-severe curves) and healthy controls.

SUMMARY OF BACKGROUND DATA

Several studies have reported abnormalities in biochemical, electromyographic activity, and histological changes of PSM in AIS. However, these studies only had qualitative data and without comparison with controls. Changes of muscle mass and mean density at the lumbar region have been described for scoliotic spines. All these findings suggested that imbalance of PSM in AIS could be a contributing factor to the development of severe scoliotic curve.

METHODS

T2-weighted MR images with multi-planar reconstruction were acquired in 41 Chinese AIS girls with a primary right-sided thoracic curve and 23 age-matched controls. In AIS, measurements of PSM were taken on both concavity and convexity of scoliosis starting from two vertebrae above and two below the apex. Morphological assessments of the multifidus (MF) and erector spinae (ES) muscles on both sides were made including signal intensity (SI) and fat deposition using manual tracing and thresholding technique, respectively. Same parameters were measured in controls at matched vertebrae. One-way analysis of variance (ANOVA) and Pearson correlation tests were used for statistical analysis.

RESULTS

Abnormalities were found at concavity of muscles between AIS and controls. Significantly higher SI and fatty components was observed in AIS at MF muscles on concavity than controls (P-value <0.001). Additionally, SI at MF muscles was significantly correlated with Cobb angle.

CONCLUSION

Increased SI and fatty components are asymmetrically present in PSM at apex in AIS. Our results showed higher intensity in PSM at concavity in AIS when compared with controls. There was a significant linear correlation between abnormal muscle signal and scoliotic curve. Above features are suggestive of altered muscle composition in concave PSM, possibly due to prolonged compression and reduced muscle activity of PSM caused by the spinal deformity.

LEVEL OF EVIDENCE

4.

Home mechanical ventilation: a Canadian Thoracic Society clinical practice guideline

Increasing numbers of patients are surviving episodes of prolonged mechanical ventilation or benefitting from the recent availability of userfriendly noninvasive ventilators. Although many publications pertaining to specific aspects of home mechanical ventilation (HMV) exist, very few comprehensive guidelines that bring together all of the current literature on patients at risk for or using mechanical ventilatory support are available. The Canadian Thoracic Society HMV Guideline Committee has reviewed the available English literature on topics related to HMV in adults, and completed a detailed guideline that will help standardize and improve the assessment and management of individuals requiring noninvasive or invasive HMV. The guideline provides a disease-specific review of illnesses including amyotrophic lateral sclerosis, spinal cord injury, muscular dystrophies, myotonic dystrophy, kyphoscoliosis, post-polio syndrome, central hypoventilation syndrome, obesity hypoventilation syndrome, and chronic obstructive pulmonary disease as well as important common themes such as airway clearance and the process of transition to home. The guidelines have been extensively reviewed by international experts, allied health professionals and target audiences. They will be updated on a regular basis to incorporate any new information.

Survival of Patients With Kyphoscoliosis Receiving Mechanical Ventilation or Oxygen at Home

BACKGROUND

Home mechanical ventilation (HMV) and long-term oxygen therapy (LTOT) are the two treatment alternatives when treating respiratory insufficiency in patients with kyphoscoliosis. We aimed to study the effect on survival with regard to HMV or LTOT alone in patients with respiratory insufficiency due to kyphoscoliosis.

METHODS

Swedish patients with nonparalytic kyphoscoliosis (ie, scoliosis not related to neuromuscular disorders) who started LTOT or HMV between 1996 and 2004 were followed up prospectively until February 14, 2006, with death as the primary outcome. Treatment modality, arterial blood gas levels, the presence of concomitant respiratory diseases, and age were recorded at the onset of treatment. No patient was lost to follow-up.

RESULTS

One hundred patients received HMV, and 144 patients received oxygen therapy alone. Patients treated with HMV experienced better survival, even when adjusting for age, gender, concomitant respiratory diseases, and blood gas levels, with a hazard ratio of 0.30 (95% confidence interval, 0.18 to 0.51).

CONCLUSION

The survival of patients with kyphoscoliosis receiving HMV was better than that of patients treated with LTOT alone. We suggest HMV and not oxygen therapy alone as the primary therapy for patients with respiratory failure due to kyphoscoliosis, regardless of gender, age, and the occurrence of concomitant respiratory diseases.

Outcomes of adult domiciliary oxygen therapy in pulmonary diseases

Domiciliary oxygen therapy has been used during the last five decades to alleviate hypoxemia and its consequences. It is considered to be one of the most expensive therapeutic methods currently available, but it is also the only therapeutic approach that can prolong survival in patients with chronic hypoxemia. Domiciliary oxygen therapy is also aimed at relieving dyspnea and improving exercise capacity and sleep quality. Portable cylinders, concentrators and portable liquid systems are the main delivery systems currently available and oxygen-conserving devices attached are aimed at improving their effectiveness. In order to minimize the associated costs, appropriate patient selection and reassessment are required. Domiciliary oxygen therapy is mostly prescribed in chronic obstructive pulmonary disease - a disease caused predominantly by smoking and in which airway obstruction results in reduced arterial oxygenation (hypoxemia). Domiciliary oxygen therapy effectiveness is best evaluated and documented in chronic obstructive pulmonary disease, which also accounts for most of its prescriptions. Therefore, this review focuses predominantly on this disease-related oxygen therapy.

Prognostic value of hypercapnia in patients with chronic respiratory failure during long-term oxygen therapy

Hypercapnia observed in patients with chronic respiratory failure may not be an ominous sign for prognosis when they are receiving long-term oxygen therapy (LTOT). In this study, we selected 4,552 patients with chronic obstructive pulmonary disease (COPD) and 3,028 with sequelae of pulmonary tuberculosis (TBsq) receiving LTOT from 1985 to 1993 throughout Japan and prospectively analyzed their prognoses. The hypercapnic patients (PaCO2 >= 45 mm Hg) had a better prognosis than the normocapnic patients (35 <= PaCO2 < 45 mm Hg) for TBsq, but no difference was found between the two groups with COPD. Furthermore, Cox's proportional hazards model revealed that in TBsq hypercapnia was an independent factor for favorable prognosis, and that the relative risk for mortality was 0.76 in patients with 45 <= PaCO2 < 55 mm Hg, 0.64 for those with 55 <= PaCO2 < 65 mm Hg, and 0. 49 for patients with PaCO2 >= 65 mm Hg against normocapnic patients. This favorable effect of hypercapnia in TBsq was particularly apparent in the patients without severe airway obstruction. Even a rise of 5 mm Hg or more in PaCO2 over the initial 6- to 18-mo follow-up period was not associated with poor prognosis in TBsq, although it was in COPD. From these findings, we conclude that hypercapnia should not be generally considered an ominous sign for prognosis in those patients who receive LTOT.

Neuromuscular ventilatory insufficiency: effect of home mechanical ventilator use v oxygen therapy on pneumonia and hospitalization rates

The purpose of this study was to determine rates of pneumonia and hospitalization for patients receiving oxygen therapy, patients having indwelling tracheostomy tubes, and those using tracheostomy or noninvasive methods of home mechanical ventilation. Six hundred eighty-four users of assisted ventilation for 13,751 patient-years or 19.8 years per patient were surveyed by mail and twice by telephone over a span of four years. Pneumonia and hospitalization rates were significantly higher for ventilator users with chronic obstructive pulmonary disease or with neuromuscular ventilatory insufficiency and gastrostomy tubes than for ventilator users with neuromuscular ventilatory insufficiency without gastrostomy tubes. Of the latter group, more than 90% of the pneumonias and hospitalizations were triggered by otherwise benign intercurrent upper respiratory tract infections. Oxygen therapy was associated with a significantly (P < 0.001) higher rate of pneumonias and hospitalizations than that seen for untreated patients after initial episodes of respiratory distress or during the use of either tracheostomy intermittent positive pressure ventilation or noninvasive ventilatory assistance methods. The lowest pneumonia and hospitalization rates (P < 0.001) were by full-time, noninvasive intermittent positive pressure ventilation users. We conclude that oxygen therapy is not an effective substitute for assisted ventilation for patients with primarily ventilatory insufficiency. Noninvasive ventilatory aids can be used effectively for up to full-time ventilatory support for patients with neuromuscular conditions whose bulbar muscle function is adequate to avert the need for gastrostomy tube placement.

Predictors of survival in patients receiving domiciliary oxygen therapy or mechanical ventilation. A 10-year analysis of ANTADIR Observatory

STUDY OBJECTIVE

To analyze predictors of survival for patients receiving home long-term oxygen therapy (LTOT) or prolonged mechanical ventilation (PMV) according to the cause of chronic respiratory insufficiency (CRI) and the patients physiologic data.

DESIGN

Analysis of a nationwide database (ANTADIR Observatory).

SETTING

The national nonprofit network for home treatment of patients with CRI Association Nationale pour le Traitement a Domicile de lInsuffisance Respiratoire Chronique (ANTADIR); founded in France in the 1980s.

PATIENTS

There were 26,140 patients receiving LTOT or PMV (noninvasive or via tracheostomy) between January 1, 1984 and January 1, 1993 (chronic bronchitis, 12,043; asthma, 1,755; bronchiectasis, 1,556; emphysema, 551; tuberculosis sequelae, 4,147; kyphoscoliosis, 1,574; neuromuscular diseases, 1,097; pneumoconiosis, 919; and fibrosis, 2,498.

MEASUREMENTS AND RESULTS

Survival analysis was performed using the actuarial and the Cox's semiparametric model. The mean survival for patients with chronic bronchitis is 3 years. Survival is slightly better for patients with bronchiectasis and asthma and worse for those with emphysema. Patients with kyphoscoliosis and a neuromuscular disease have the longest survival (8 and 6.5 years, respectively). Patients with CRI due to tuberculosis sequelae experience the same survival as COPD patients (3 years). Prognosis is the worst in patients with pneumoconiosis or fibrosis: 50% of these patients die during the year following the beginning of home treatment. The association of an obstructive lung disease worsens the prognosis of patients with kyphoscoliosis or neuromuscular disease and tends to bring the survival rate of the patients with pneumoconiosis or fibrosis closer to that of COPD patients. In COPD, male sex, older age, lower body mass index (BMI),FEV1 percent predicted,PaO2,and PaCO2 are independent negative prognostic factors. For tuberculous sequelae and kyphoscoliosis, female sex, younger age, a high BMI, PaO2 and PaCO2 (and for kyphoscoliosis a higher FEV1/vital capacity [VC] ratio) are all independent favorable prognostic factors. In pulmonary fibrosis, a lower PaO2 and PaCO2 values, a lower VC percent predicted, and a higher FEV1/VC ratio are negative prognostic factors.

CONCLUSIONS

The ANTADIR Observatory allows a unique opportunity to analyze long-term survival of a large population with CRI treated at home.