Lung function in Duchenne muscular dystrophy

Summary Over 90% of patients with Duchenne muscular dystrophy develop a scoliosis when they become wheelchair bound. The scoliosis is progressive and is associated with deteriorating lung function. The purpose of this study was firstly to assess whether a standing regimen, in patients who had gone off their feet, protected against the development of scoliosis and affected their lung function, and secondly to evaluate the effect of spinal stabilisation in patients who had developed a progressive scoliosis. The results of the first part of this study showed that a standing regimen significantly delayed the progression of scoliosis and that patients who complied with the standing regimen had a significantly better lung function, as measured by vital capacity and peak expiratory flow rate, than those patients who did not stand. Spinal stabilisation prevented deterioration in the scoliosis, whereas the deformity continued to progress relentlessly in patients who did not undergo surgery. The patients who underwent spinal stabilisation maintained a significantly better lung function and had an improved survival compared with the patients who refused surgery.Paper read at the ESDS meeting, Birmingham 1994, and selected for full publication.     

Effect of spinal surgery on lung function in Duchenne muscular dystrophy.

BACKGROUND--The effect on subsequent respiratory function of spinal stabilisation for scoliosis in Duchenne muscular dystrophy is unclear. In order to clarify this clinical problem, changes in the forced vital capacity of a group of children with Duchenne muscular dystrophy who had undergone spinal surgery were measured and compared with a group of children with Duchenne muscular dystrophy who had not had surgery. METHODS--In this retrospective study 17 boys with Duchenne muscular dystrophy who underwent spinal stabilisation at a mean age of 14.9 years (surgical group) were compared with 21 boys with Duchenne muscular dystrophy who had not had surgery (non-surgical group). The mean (SD) Cobb angle of the surgical group at 14.9 years was 57 (16.4) degrees, and of the non-surgical group at 15 years was 45 (29.9) degrees. Forced vital capacity expressed as percentage predicted (% FVC) was measured in total over a seven year period in the surgical group and over 6.5 years in the non-surgical group, and regression equations were calculated. Survival curves for both groups were also constructed. RESULTS--No difference was found between spinal stabilisation (surgical group) and the non-surgical group in the rate of deterioration of % FVC which was 3-5% per year. There was no difference in survival in either group. CONCLUSIONS--Spinal stabilisation in Duchenne muscular dystrophy does not alter the decline in pulmonary function, nor does it improve survival.     

Pulmonary function before and after anterior spinal surgery in adult idiopathic scoliosis.

BACKGROUND: Little is known about the long term effects of anterior spinal surgery on pulmonary function in adult patients with idiopathic scoliosis. A study was therefore undertaken of pulmonary function before and after anterior spinal surgery in this group of patients. METHODS: Fourteen patients (12 women) of mean age 26.5 years (range 17-50, 10 > or = 20 years) were studied. All 14 patients underwent thoracotomy and anterior arthrodesis, and five also underwent posterior arthrodesis. Scoliosis curves and lung volumes were measured preoperatively and at a mean follow up of 32 months (range 14-49) after surgery. RESULTS: At long term follow up after surgery the mean (SD) Cobb angle of the thoracic curve improved from 59 degrees (25 degrees) to 39 degrees (18 degrees), a correction of 31%. Despite this there was a fall in mean forced vital capacity (FVC) of 0.21 litres (95% confidence interval 0.04 to 0.38). In the patients who underwent anterior surgery without posterior surgery (n = 9) there was a fall in mean FVC of 0.31 litres (95% confidence interval 0.12 to 0.50); mean forced expiratory volume in one second and total lung capacity were also reduced and there was an increase in mean residual volume. CONCLUSIONS: Forced vital capacity is reduced at long term follow up in adult patients with idiopathic scoliosis who undergo anterior spinal surgery. The fall in FVC is small and is unlikely to be of clinical significance in patients with reasonable lung function in whom surgery is planned for prevention of curve progression or improvement of cosmetic appearance and pain. However, surgical intervention should not be undertaken in an attempt to improve pulmonary function.     

Respiratory functions in thermal burns

In our present series, respiratory functions were observed in patients with a relatively small extent of burn compared to that commonly represented by the published works, and for a considerable duration of time (three weeks), commencing soon after the burn trauma. Respiratory rate increased in the post burn trauma and the peak expiratory rate was observed on the 8th post burn days and then it gradually fell but still remaining much higher than the control normal value. The minute volume and tidal volume also showed similar rise on the 8th post burn day and then gradually fell to below the mean level of 3rd post burn day before the 3rd post burn week.Forced vital capacity, forced expiratory volume in one second, forced expiratory volume in three seconds, forced expiratory volume in one second as a percentage of forced vital capacity, forced expiratory volume in three seconds, as a percentage of forced vital capacity and peak expiratory flow rates, did not vary much and indicated no significant respiratory abnormality.     

Pulmonary function in adolescent idiopathic scoliosis relative to the surgical procedure

BACKGROUND: The long-term pulmonary function of patients with adolescent idiopathic scoliosis undergoing surgical correction is uncertain. To our knowledge, no report has demonstrated the changes in pulmonary function five years or more following spinal arthrodesis with use of modern segmental spinal instrumentation techniques for the treatment of all types of adolescent idiopathic scoliosis in a similar adolescent population. METHODS: One hundred and eighteen patients with adolescent idiopathic scoliosis undergoing surgical treatment at a single institution were evaluated with pulmonary function tests to assess the absolute and percent-predicted value of forced vital capacity and forced expiratory volume in one second at the preoperative examination and at regular intervals postoperatively. The patients were divided into four groups depending upon the surgical procedure: Group 1 comprised forty-nine patients who had posterior spinal arthrodesis with iliac crest bone graft; Group 2, forty-one patients who had posterior spinal arthrodesis with thoracoplasty; Group 3, sixteen patients who had open anterior spinal arthrodesis with a rib resection thoracotomy; and Group 4, twelve patients who had combined anterior and posterior spinal arthrodesis with a rib resection thoracotomy and iliac crest bone graft, respectively. RESULTS: A comparison of absolute pulmonary function values from the preoperative and final follow-up evaluations demonstrated a significant (p < 0.0001) increase in both the forced vital capacity and the forced expiratory volume in one second for Group 1, whereas no change was seen in those values for Groups 2, 3, and 4. A comparison of the changes in the percent-predicted pulmonary function values demonstrated significant (p < 0.05) decreases in forced vital capacity and forced expiratory volume in one second for Groups 2, 3, and 4, except for the latter value for Group 4, whereas Group 1 had no change. CONCLUSIONS: Patients who have had any type of chest cage disruption during the surgical treatment of adolescent idiopathic scoliosis demonstrate no change in the absolute value and a significant decline in the percent-predicted value of pulmonary functions at five years following surgery. Chest cage preservation is recommended to maximize both absolute and percent-predicted pulmonary function values after surgical treatment of adolescent idiopathic scoliosis.     

Changes in pulmonary function tests during spinal anaesthesia for caesarean section

We report the changes in forced vital capacity, forced expiratory volume in 1 s, and peak expiratory flow rate during caesarean section under spinal anaesthesia, as indirect indices of the ability to cough effectively. There were progressive falls in forced expiratory volume in 1 s (FEV(1)), forced vital capacity (FVC) and peak expiratory flow rate (PEFR) from the onset of anaesthesia till the abdomen was open, with these results failing to return to pre-incision levels by the time the patient reached the recovery room. Although none of our patients complained of dyspnoea or difficulty in coughing such falls in PEFR and FEV(1) may lead to an inability to cough effectively or clear inhaled vomit especially in patients with previously impaired respiratory function.     

Airflow in unilateral vocal cord paralysis before and after Teflon injection.

The effect of unilateral vocal cord paralysis and intracordal Teflon injection on maximum expiratory and inspiratory flows was studied in 15 consecutive patients. Ten patients had a ratio of forced expiratory flow to forced inspiratory flow at 50% vital capacity (Ve50/Vi50) more than one. Of the remaining five, four had low Ve50 consistent with underlying bronchial disease. Repeat studies were obtained in 10 patients two or more weeks after Teflon injection into a vocal cord for voice therapy. Maximum expiratory flow rates did not change (means 6.64 +/- 0.881/sec before and 6.47 +/- 1.101/s after injection). Inspiratory flow at 50% vital capacity improved in all six patients with a forced expiratory volume in one second (FEV1) greater than 75% of the forced vital capacity (FVC). In patients with an FEV1 less than 75% FVC, no consistent changes could be seen. We conclude that a high Ve50/Vi50 suggestive of variable extrathoracic airways obstruction is a frequent finding in the presence of unilateral vocal cord paralysis. Teflon injection does not cause a significant reduction in forced expiratory flows and improves inspiratory flows in subjects without evidence of underlying bronchial disease.     

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

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

Pulmonary function and pain after gastroplasty performed via laparotomy or laparoscopy in morbidly obese patients

We have compared severely obese patients (body mass index > 35 kg m-2) undergoing laparoscopic or open gastroplasty (n = 15 in each group) to determine if laparoscopy results in any benefit in the obese. Postoperative pain, measured on a 100-mm visual analogue scale, and opioid consumption were recorded during the first two days after operation. Tests of pulmonary function were performed and SpO2 was measured 4 h after surgery and on days 1, 2 and 3 after operation. Pain at rest was similar in the two groups, but in the laparoscopy group, requirements for postoperative opioid were 50% less (P < 0.05). Pain intensity during mobilization and on coughing was significantly less after laparoscopy (differences between mean pain scores in both groups ranged from 20 to 32 mm during mobilization and from 32 to 34 mm during coughing). Forced vital capacity, forced expiratory volume in 1 s and peak expiratory flow rate were reduced significantly less after laparoscopic gastroplasty than after open gastroplasty (on day 1 forced vital capacity was reduced by 50% compared with 64%, forced expiratory volume in 1 s was reduced by 50% compared with 66% and peak expiratory flow rate by 45% compared with 60%). SpO2 values were significantly greater in the laparoscopy group (day 1: mean 95 (SD 2)% vs 91 (5)%; day 3: 97 (1)% vs 94 (3)%). This study suggests that the beneficial effects observed after laparoscopic gastroplasty in morbidly obese patients were similar to those reported after laparoscopic cholecystectomy in non-obese patients.      

Pulmonary function after thoracoplasty in adolescent idiopathic scoliosis

The current study evaluated sequential pulmonary function tests prospectively at a minimum of 2 years after thoracoplasty in adolescent patients with idiopathic scoliosis. Twenty patients were divided into two groups: Group I (n=12) was comprised of patients who had posterior instrumented fusion with external thoracoplasty, and Group II (n=8) was comprised of patients who in addition to a posterior instrumented fusion, had an anterior release and fusion via video-assisted thoracoscopic surgery (n=4) or open thoracotomy (n=4) because of rigid severity. Forced vital capacity and forced expiratory volume in 1 second of percent predicted values in Group I declined 9% at 3 months postoperatively and returned to the preoperative baseline at 1 year. However, forced vital capacity and forced expiratory volume in 1 second of percent predicted values in Group II declined 11% to 18% postoperatively and did not return to the preoperative baseline at 2 years. Posterior instrumented fusion with thoracoplasty in adolescent patients with idiopathic scoliosis significantly decreased pulmonary function at 3 months, but returned to the preoperative baseline at 1 year. The addition of an anterior releasing procedure resulted in poorer pulmonary function, which did not return to the preoperative baseline by the 2-year followup.     

A dose response study of oxitropium bromide in chronic bronchitis

In a dose response study 12 patients with chronic bronchitis and airflow obstruction received inhaled placebo and incremental doses of oxitropium bromide. Significant improvements in peak expiratory flow rate, forced expiratory volume in one second, and forced vital capacity were recorded at all times up to 10 hours after all doses of oxitropium bromide. Oxitropium bromide is an effective bronchodilator in chronic bronchitis with an optimal dose of 400-600 micrograms.     

Pulmonary function in adolescents with mild idiopathic scoliosis.

Spirometric indices, lung volumes, maximum voluntary ventilation, and maximum inspiratory and expiratory pressures were measured in 44 adolescents with mild idiopathic scoliosis (spinal curvature less than 30 degrees). All were symptom free, but six (13.6%) showed a restrictive defect with forced vital capacity less than 80% of predicted. In 12 subjects (27.3%) maximum voluntary ventilation was reduced to less than 80% of predicted normal. Forced vital capacity was significantly correlated with maximum inspiratory pressure and with maximum expiratory pressure, measures of respiratory muscle strength, but was not related to the degree of thoracic curvature. When maximum inspiratory pressure and forced vital capacity were corrected for differences in body size these variables remained positively correlated, most significantly in the girls. These data indicate that ventilatory function may be impaired in mild, idiopathic scoliosis and that the force developed by the respiratory muscles is a more important determinant of this impairment than the radiologically determined degree of spinal curvature.     

All pedicle screw fixation technique in correcting severe kyphoscoliosis in an osteogenesis imperfecta patient: a case report

Spinal deformity in patients with osteogenesis imperfecta demonstrates a high prevalence. The surgical treatment of this problem had numerous difficulties, which included breakage of bone, dislodgement of implants, and late loss of correction. We reported the correction of severe kyphoscoliosis in a patient with osteogenesis imperfecta using 3-rod all pedicle screw fixation technique. In this case, the 2 main goals of spinal operation, stabilization and correction of spinal curvatures, were achieved. The Cobb angles of scoliosis and thoracic kyphosis were corrected from 110 degrees to 68 degrees and from 107 degrees to 39 degrees, respectively. One and a half years after the operation, spinal radiographs showed no loss of correction, either on coronal or sagittal planes. The predicted forced vital capacity, predicted forced expiratory volume in 1 second and vital capacity of the lung of the patient had improved 2-fold. The usage of pedicle screw, with its conical core and cylindrical thread design, and 3-rod technique in fixation, together with cyclic intravenous bisphosphonate administration and halo-gravity traction preoperatively, contributed to the success in this case.     

Accelerometry of Adductor Pollicis Muscle Predicts Recovery of Respiratory Function from Neuromuscular Blockade

Background: Residual paralysis increases the risk of pulmonary complications but is difficult to detect. To test the hypothesis that accelerometry predicts effects of residual paralysis on pulmonary and upper airway function, the authors related tests of pulmonary and pharyngeal function to accelerometry of adductor pollicis muscle in 12 partially paralyzed volunteers.

Methods: Rocuronium (0.01 mg/kg + 2-10 [mu]g [middle dot] kg-1 [middle dot] min-1) was administered to maintain train-of-four (TOF) ratios (assessed every 15 s) of approximately 0.5 and 0.8 over a period of more than 5 min. The authors evaluated pharyngeal and facial muscle functions during steady state relaxation and performed spirometric measurements every 5 min until recovery. Upper airway obstruction was defined as a mean ratio of expiratory and inspiratory flow at 50% of vital capacity of greater than 1. The TOF ratio associated with "acceptable" pulmonary recovery (forced vital capacity and forced inspiratory volume in 1 s of >=90% of baseline) was calculated using a linear regression model.

Results: At peak blockade (TOF ratio 0.5 +/- 0.16), forced inspiratory flow was impaired (53 +/- 19%) to a greater degree than forced expiratory flow (75 +/- 20%) with a mean ratio of expiratory and inspiratory flow at 50% of vital capacity of 1.18 +/- 0.6. Upper airway obstruction, observed in 8 of 12 volunteers, paralleled an impaired ability to swallow reported by 10 of 12 volunteers. In contrast, all volunteers except one could sustain a head lift for more than 5 s. The authors calculated that a mean TOF ratio of 0.56 (95% confidence interval, 0.22-0.71) predicts "acceptable" recovery of forced vital capacity, whereas forced inspiratory volume in 1 s was impaired until a TOF ratio of 0.95 (0.82-1.18) was reached. A 100% recovery of TOF ratio predicts an acceptable recovery of forced vital capacity, forced inspiratory volume in 1 s, and mean ratio of expiratory and inspiratory flow at 50% of vital capacity in 93%, 73%, and 88% of measurements (calculated negative predictive values), respectively.     

Respiratory effects of spinal anaesthesia for Caesarean section

We report the changes observed in a number of pulmonary function tests performed on 36 patients undergoing Caesarean section under spinal anaesthesia. The tests comprised peak expiratory flow, forced expiratory volume in one second, forced vital capacity, forced expiratory volume in one second to forced vital capacity ratio and the maximal mid-expiratory flow. Significant changes occurred that are consistent with a restrictive ventilatory defect. These changes persisted for four hours after the induction of spinal anaesthesia. Administration of 35% oxygen by facemask failed to change significantly fetal umbilical vein pH or partial pressure of oxygen.     

Accelerometry of adductor pollicis muscle predicts recovery of respiratory function from neuromuscular blockade

BACKGROUND: Residual paralysis increases the risk of pulmonary complications but is difficult to detect. To test the hypothesis that accelerometry predicts effects of residual paralysis on pulmonary and upper airway function, the authors related tests of pulmonary and pharyngeal function to accelerometry of adductor pollicis muscle in 12 partially paralyzed volunteers. METHODS: Rocuronium (0.01 mg/kg + 2-10 microg x kg-1 x min-1) was administered to maintain train-of-four (TOF) ratios (assessed every 15 s) of approximately 0.5 and 0.8 over a period of more than 5 min. The authors evaluated pharyngeal and facial muscle functions during steady state relaxation and performed spirometric measurements every 5 min until recovery. Upper airway obstruction was defined as a mean ratio of expiratory and inspiratory flow at 50% of vital capacity of greater than 1. The TOF ratio associated with "acceptable" pulmonary recovery (forced vital capacity and forced inspiratory volume in 1 s of > or =90% of baseline) was calculated using a linear regression model. RESULTS: At peak blockade (TOF ratio 0.5 +/- 0.16), forced inspiratory flow was impaired (53 +/- 19%) to a greater degree than forced expiratory flow (75 +/- 20%) with a mean ratio of expiratory and inspiratory flow at 50% of vital capacity of 1.18 +/- 0.6. Upper airway obstruction, observed in 8 of 12 volunteers, paralleled an impaired ability to swallow reported by 10 of 12 volunteers. In contrast, all volunteers except one could sustain a head lift for more than 5 s. The authors calculated that a mean TOF ratio of 0.56 (95% confidence interval, 0.22-0.71) predicts "acceptable" recovery of forced vital capacity, whereas forced inspiratory volume in 1 s was impaired until a TOF ratio of 0.95 (0.82-1.18) was reached. A 100% recovery of TOF ratio predicts an acceptable recovery of forced vital capacity, forced inspiratory volume in 1 s, and mean ratio of expiratory and inspiratory flow at 50% of vital capacity in 93%, 73%, and 88% of measurements (calculated negative predictive values), respectively. CONCLUSION: Impaired inspiratory flow and upper airway obstruction frequently occur during minimal neuromuscular blockade (TOF ratio 0.8), and extubation may put the patient at risk. Although a TOF ratio of unity predicts a high probability of adequate recovery from neuromuscular blockade, respiratory function can still be impaired.     

Scoliosis and lung function in spinal muscular atrophy

Summary The notes and radiographs of 43 patients with a confirmed diagnosis of spinal muscular atrophy were reviewed. A significant inverse linear relationship between the severity of scoliosis and the percentage of predicted vital capacity and peak flow was found. The patients who stood had a significantly better lung function than patients who were confined to a wheelchair, and their scoliosis deteriorated significantly more slowly. Sixteen patients underwent surgical spinal stabilisation, 4 with Harrington instrumentation and 12 with segmental spinal instrumentation, at an average age of 12 years and 11 months. The average curve correction achieved was 40%. The decline in lung function seen pre-operatively was not only reversed, but a significant improvement was found at final follow-up.Paper read at the ESDS meeting, Birmingham, 1994, and selected for full publication.     

Physiological effect of endobronchial radiotherapy in patients with major airway occlusion by carcinoma.

BACKGROUND: Endobronchial radiotherapy by a high dose rate remote after-loading technique (high dose rate brachytherapy) has become an established treatment for major airway occlusion by inoperable carcinoma of the bronchus. Only limited objective data on its effect on pulmonary physiology and on radiographic and bronchoscopic appearances are available. The aim of this study was to make a detailed assessment of patients before and after high dose rate brachytherapy to determine which investigations were useful and to generate data for comparing this with other methods of treatment. METHODS: Twenty patients with major airway obstruction by inoperable lung cancer underwent a detailed assessment before receiving endobronchial radiotherapy (15 Gy at 1 cm in a single fraction) and six weeks after treatment. This included chest radiography, computed tomography of the thorax, bronchoscopy including an obstruction index, five minute walking tests, isotope ventilation and perfusion lung scanning, and full lung function tests with maximum inspiratory and expiratory flow-volume loops. RESULTS: Nineteen patients (mean age 69 years) completed the study. Symptomatic improvement occurred in 17 patients. A collapsed lobe or lung, seen on the chest radiograph in 13, reexpanded in nine. Bronchoscopic appearances improved in 18, the mean obstruction index decreasing from 6.2 to 2.8. The isotope scans showed significant increases in the percentage of total lung ventilation (V) and perfusion (Q) measured over the abnormal lung (V 17.7% to 27.7%, Q 15.1 to 21.9%). Five minute walking distance (305 to 329 m), forced expiratory volume in one second (FEV1 1.45 to 1.61 l), forced vital capacity (FVC 2.17 to 2.48 l) and ratio of forced expiratory to forced inspiratory flow rate at 50% vital capacity (FEF50/FIF50 0.58 to 0.88) all increased significantly. CONCLUSIONS: Endobronchial radiotherapy led to subjective benefit in most cases in terms of symptoms and bronchoscopic and radiological appearances. There was objective improvement in spirometric indices and in exercise tolerance with increased pulmonary ventilation and perfusion and evidence of decreased intrathoracic airway obstruction.     

A trial of oral delta-1-(trans)-tetrahydrocannabinol in reversible airways obstruction.

Sixteen patients with proven reversible airways obstruction were admitted to a double-blind study to compare the bronchodilator effects of oral delta-1-(trans)-tetrahydrocannabinol (delta-1-THC) and salbutamol. Measurements of forced vital capacity, forced expired volume in one second, peak expiratory flow rate, and maximum expiratory flow rate at 50 percent vital capacity after 10 mg oral delta-1-THC did not differ significantly from the effect of placebo, whereas increases after salbutamol were significant. Analyses of mood, pulse rate, blood pressure, and electrocardiogram showed no important changes after oral delta-1-THC. In vitro studies with isolated tracheal muscle indicate that the activity of delta-1-THC is 1,000 times less than the equivalent dose of isoprenaline, and the effect of delta-1-THC is not abolished by beta-adrenoreceptor blocking agents. It is concluded that oral delta-1-THC, at a dose of 10 mg, does not produce clinically significant bronchodilatation in patients with reversible airways obstruction.     

Effect of scoliosis surgery on pulmonary function in patients with myelomeningocele

Thirteen patients with myelomeningocele who required operation for scoliosis were tested for changes in pulmonary function 1 month before and an average of 13 months after spinal stabilization. The average age at the time of operation was 12 years 11 months. Ten patients had restrictive changes in pulmonary function preoperatively. Owing to the severity of scoliosis, an anterior approach to the spine including resection of ribs and division of the diaphragm was necessary for eight children. Postoperatively, despite these procedures, eight patients had an increase in vital capacity and six patients had an increased forced expiratory volume in 1 s.