PubMed Health⌕ Search

Biomedical subjects

J M Shneerson

Publications and source records attributed to J M Shneerson.

At least 19 recordsLinked to original sources
PubMed1992

Extrinsic allergic alveolitis: problems in diagnosis and a potential use for computed tomography.

Bird fancier's lung, the most common form of extrinsic allergic alveolitis in Britain, can be a difficult diagnostic problem. The symptoms are non-specific, often insidious in onset and frequently misdiagnosed as influenza or a viral or bacterial pneumonia. Frequently there is a delay in eliciting the history of exposure to the antigen. The chest radiograph is often less impressive than the clinical presentation and may be normal despite severe symptoms, impaired respiratory function and florid pathological changes. We present three cases demonstrating these diagnostic problem. In two cases, high resolution computed tomography demonstrated the typical 'ground glass' opacification seen in active alveolitis. This allowed targeting of transbronchial biopsies which revealed an inflammatory infiltrate of the interstitium with granuloma formation and inflammatory cells in some alveoli. The problems in diagnosis and the potential role of high resolution computed tomography are discussed.

Adult↗
PubMed1992

The relief of snoring by nasal surgery.

Patients with nasal obstruction may also complain of snoring. It is uncertain whether surgery which relieves the nasal obstruction will also relieve the snoring. We have reviewed 126 patients who complained of both nasal obstruction and snoring and who underwent nasal surgery. Snoring was completely relieved in 39 patients (31%), was less loud in a further 72 patients (57%), unchanged in 11 and louder in 4. It occurred on fewer nights post-operatively in 61, on the same number in 24 and more frequently in 2. Patients who had nasal polypectomy as part of their nasal surgery obtained the greatest snoring relief. This study suggests that when snoring and nasal obstruction coexist nasal surgery should be considered as the first line of surgical treatment.

Humans↗
PubMed1992

Clinical experience and physiologic results with an implantable intratracheal oxygen catheter.

Ten patients with chronic lung disease received an implanted ITOC. Seven patients continue to use their catheters after a mean period of 14.75 months. Four catheters were removed, 2 at 1 month, 1 after 10 months and 1 after 13 months. One patient requested a second catheter. Three patients experienced mucus plug formation; this was transient in two patients, but led to removal of the catheter in the third. To determine the degree of oxygen-saving afforded by the ITOC, SaO2 was measured at rest and during exercise for eight of the ten subjects using a double-blind technique. The calculated oxygen savings were around 40 percent both at rest and during exercise. The ITOCs were well received by the majority of our patients and were shown to produce a useful saving of oxygen which is of benefit to patients using portable systems and those who require high oxygen flow rates.

Adult↗
PubMed1992

Inter-machine variability in the stability of continuous positive airway pressure.

Two studies were performed to investigate the differences in pressure stability performance of the continuous positive airway pressure (CPAP) machines used by our patients. The variations of mask pressures during each respiratory cycle were measured during overnight studies of two groups of patients with obstructive sleep apnoea, who were using either a Sleep-Easy III CPAP machine or a Si-Plan CPAP unit. The patients were well-matched for age, weight and neck circumference. The group using the Si-Plan unit had more constant mask pressures and were using lower CPAP pressures (mean 10.6 cmH2O) than those using the Sleep-Easy III machine (mean 13.8 cmH2O) (p less than 0.02). The pressure stability performance of five CPAP machines used by our patients was also compared using standardized simulated patient breaths produced by a negative pressure cuirass pump. There were large differences between the machines in ability to maintain a constant pressure. Using a tidal volume of 0.5 l and peak flow rates of between 20-40 l.min-1 the pressure variation ranged from 0-67% of the minimum inspiratory pressure. The maintenance of a constant pressure during inspiration and expiration lowers the mean pressure required to eliminate obstructive sleep apnoeas and reduces the likelihood of pressure related side-effects.

Adult↗
PubMed1990

Obstructing tracheal lipoma: management of a rare tumor.

Benign neoplasms of the trachea are rare. We describe a 46-year-old patient with a lipoma arising from the membranous trachea and causing severe respiratory obstruction. Investigation and management of this problem are discussed, and the literature is reviewed.

Airway Obstruction↗
PubMed1990

Phrenic nerve stimulation for central ventilatory failure with bipolar and four-pole electrode systems.

A multi-channel phrenic nerve stimulator developed in Tampere has been implanted into seven patients with C2-tetraplegia and into three patients with central sleep apneas. Six bipolar cuff electrodes were implanted bilaterally into the neck. Two four-pole cuff and 14 four-pole noncuff electrodes were used in seven patients and to replace one bipolar electrode. Four-pole electrodes were implanted within the thorax. Seven patients achieved total independence from conventional ventilators within 4 months of implantation, and one for 18 hours each day. Two patients died 12 days and 3 months after implantation and two patients after having achieved independence from mechanical ventilators from causes unrelated to the stimulators. Reoperations were necessary because of dislocation of receivers, electrodes, electrode lesions, nerve injuries, and technical failures in seven patients. Most of the problems appeared in two patients with obesity and in three patients with very thin phrenic nerves. Single unit prototypes failed technically more frequently than units of prototype serial fabrication. New electrode design, progress in the manufacture of receivers, and improved implantation technique should help to diminish failures in future.

Adolescent↗
PubMed1989

Respiratory pump failure and its treatment.

The activity of the nervous system determines the respiratory pattern, although the degree of alveolar ventilation also depends on the mechanical properties of the chest wall and lungs. Failure to ventilate the lungs adequately may be due to defects in respiratory control or the respiratory muscles or to an increase in the work that the muscles have to perform. The selection of the best method of treatment of respiratory pump failure requires an exact knowledge of its cause. Phrenic nerve stimulation or mechanical assistance by positive and negative pressure ventilators or by a rocking bed, can be very effective. Each of these methods has a place in the long-term management of ventilatory failure.

Beds↗
PubMed1989

Exercise responses in patients treated for pulmonary tuberculosis by thoracoplasty.

Twenty eight subjects (mean age 64 years) who had been treated for tuberculosis by thoracoplasty in the past performed an increasing work rate exercise test, from which maximum oxygen consumption (VO2max), ventilation and heart rate were measured. VO2max was significantly lower than predicted, being 0.75 l/min in 17 subjects, 1.0 l/min in 10, and 1.5 l/min in one. Only one subject achieved a heart rate of 85% of the predicted maximum. The ratio of heart rate to oxygen consumption (HR/VO2) and heart rate at standard interpolated submaximal levels of oxygen uptake at 0.75 l/min (heart rate 0.75) and 1.0 l/min (heart rate 1.0) were normal. VO2max correlated with ventilation at maximal exercise (VE max) (r = 0.87) and FEV1 (r = 0.47). It did not correlate with resting arterial oxygen or carbon dioxide tensions, FEV1, maximum inspiratory pressure, angle of scoliosis, or number of ribs resected. The relation between ventilation and oxygen consumption (VE/VO2) and VE at the submaximal levels of oxygen consumption of 0.75 l/min (VE 0.75) and 1.0 l/min (VE 1.0) were normal. In 10 subjects a plateau of breathing frequency (fmax) was reached, after which the increase in ventilation was achieved by a further increase in tidal volume (VT). These subjects showed significantly lower values for the forced expiratory ratio, VO2max, and VEmax than those with a normal relation between tidal volume and breathing frequency. VEmax was correlated with FEV1 (r = 0.61), FVC (r = 0.46), maximum VT (r = 0.55), change in VT (r = 0.52), fmax (r = 0.56), and change in breathing frequency (r = 0.72). These results indicate that exercise in patients treated for tuberculosis by thoracoplasty is limited by ventilatory capacity and that this is due to a reduction in both dynamic lung volumes and respiratory frequency.

Aged↗
PubMed1988

Appearances on computed tomography following thoracoplasty for pulmonary tuberculosis.

Thoracic computed tomography was performed in 32 patients who had undergone thoracoplasty as part of their treatment for pulmonary tuberculosis. Pleural thickening and the prevalence of bronchiectasis were more marked in the operated hemithorax. Bullae were more prevalent in the operated hemithorax but the difference was not statistically significant. In all but one patient, scoliosis was present. Illustrative examples are presented to demonstrate the range of appearances following this operation.

Bronchiectasis↗
PubMed1987

Importance of airflow obstruction after thoracoplasty.

Thirty six patients previously treated for pulmonary tuberculosis by thoracoplasty were studied to determine the prevalence and effect of airflow obstruction. The mean (SD) FEV1 was 1.3 (0.65) 1 and the mean forced expiratory ratio (FER) 64% (12%). FEV1 was less than predicted in every patient whereas FER was less than predicted in 30, being below the lower 98th percentile in 15 (42%). In the 18 patients who complained of breathlessness the means of the standardised residuals (SR) for FEV1, peak expiratory flow (PEF), and FER were significantly lower and that for residual volume/total lung capacity (RV/TLC) significantly higher than those for the 18 patients who were not breathless (all p less than 0.0001). There was no difference in the smoking history of the two groups. Only three of the 23 patients in whom reversibility of airflow obstruction was assessed showed a greater than 25% increase in PEF. None showed an increase in FEV1 of greater than 15%. The 18 who were breathless had significantly lower values of arterial oxygen tension (PaO2) and higher values of arterial carbon dioxide tension (PaCO2) (p less than 0.0001). Thirteen of these patients were in chronic respiratory failure (PaO2 less than 8.0 kPa or PaCO2 greater than 5.9 kPa, or both) compared with only one of the 18 who were not breathless. The indices correlating best with PaO2 and PaCO2 were SR FEV1 and SR PEF respectively. SR FEV1 accounted for 34% of the variance in PaO2 and SR PEF for 29% of the variance in PaCO2. Airflow obstruction has been found to be common in patients with a thoracoplasty and to be associated with hypoxia and hypercapnia.

Aged↗