PubMed Health⌕ Search

Biomedical subjects

J R Bach

Publications and source records attributed to J R Bach.

126 records · Page 7Linked to original sources
PubMed1987

Intermittent positive pressure ventilation via nasal access in the management of respiratory insufficiency.

These are preliminary observations of the introduction of a new technique of noninvasive positive pressure respiratory support for patients with subacute or chronic respiratory failure. Clinical situations where intubation or tracheostomy may have been performed were managed by intermittent positive pressure ventilation via nasal access (NIPPV) with a CPAP mask, or a custom constructed Vel-Foam nose piece. Four patients were managed at home with the use of portable volume ventilators. One patient employed the technique while hospitalized with subacute respiratory failure. Two patients, otherwise dependent on mouth intermittent positive pressure ventilation (MIPPV) 24 hours a day, received necessary dental care with NIPPV support. In a large population with a decade or more follow-up, MIPPV was shown to be an effective noninvasive technique to support respiration in patients with the most severe paralytic respiratory failure. Preliminary observations suggest that NIPPV may compare favorably with MIPPV and deserves more widespread study and application.

Adult↗
PubMedDate not supplied

Correlation of flexion contractures with upper extremity function and pain for spinal muscular atrophy and congenital myopathy patients.

To ascertain the patients' perception of the consequences of elbow flexion contractures and better understand the circumstances at their inception, we surveyed 405 spinal muscular atrophy and congenital myopathy patients. Diagrams of various elbow angles and questions concerning the effect of elbow contractures on daily activities were part of the survey. Of 108 completed responses, effectively a 24% response rate, 49 reported elbow flexion contractures. Thirteen of the 49 patients reported first noting them during extended periods of inactivity. Elbow flexion contractures greater than 25 degrees were intractable and were reported to hamper 17% (77 of 410) of specifically considered daily activities for the 49 subjects. Twenty-nine of the 49 (59%) subjects with contractures complained of contracture-associated hindrance of at least one daily function. Perceived contracture-associated difficulties increased significantly as a function of contracture severity. Elbow contractures were perceived to be useful by 12% of the respondents. The correlation between contracture severity and upper limb discomfort was also striking. We conclude that elbow flexion contractures are common and perceived to be associated with disability and discomfort for about one-half of spinal muscular atrophy and congenital myopathy patients.

Activities of Daily Living↗
PubMedDate not supplied

Medial femoral cutaneous nerve conduction.

Medial femoral cutaneous nerve (MFCN), a sensory branch of the femoral nerve, supplies the skin on the anterior medial aspect of the thigh and knee. A conduction study for this nerve is described. A recording electrode was placed anterior-medially in the thigh and 14 cm distal to the stimulating cathode that was placed immediately lateral to the femoral artery just below the inguinal ligament. Sixty-four nerves of 32 adults with a mean age of 40 yr (range, 21-56) were tested. The latencies to the onset and peak were 2.4 +/- 0.2 and 2.9 +/- 0.2 ms, respectively. The amplitude of baseline to negative peak was 4.9 +/- 1.0 microV. The conduction velocity calculated by the distance divided by the onset latency was 60 +/- 5 m/s. We conclude that the MFCN is accessible for electrophysiologic evaluation, which may help in diagnosing the MFCN or femoral neuropathy.

Adult↗
PubMedDate not supplied

Spinal muscular atrophy: kinematic breathing analysis.

Twelve children with spinal muscular atrophy (SMA) type 2 and 13 children without physical disability underwent kinematic analysis of thoracoabdominal volume changes when breathing spontaneously and when breathing deeply. A very accurate optical method of kinematic analysis was used. Volumes were partitioned into upper thoracic, lower thoracic, and abdominal compartments. Abdominal volume increases accounted for 96% of the normal tidal volumes and 87% of the deep breathing volumes for the patients, but only 74 and 41% of the volumes, respectively, for the controls. For the patients the upper thoracic contribution to breathing volumes was --1.7% for normal tidal volumes and 0.3% for deep breathing volumes. Patients with less upper thoracic kinematic reserve were also found to be more likely to have chronic nocturnal hypoventilation. We conclude that kinematic analysis can be helpful in determining differences in regional lung mobility and risk for nocturnal ventilatory dysfunction for children with SMA. Therapeutic interventions need to be addressed to maintain thoracic kinematic reserve and lung compliance and, thereby, to facilitate more normal lung growth and the ability to cough.

Adolescent↗
PubMedDate not supplied

Peroneal nerve motor conduction to the proximal muscles. An alternative approach to conventional methods.

By using a fixed 8-cm distance between the stimulating and recording electrodes, we describe a new approach to peroneal nerve motor conduction studies to the proximal muscles. The recording active electrodes were fastened over the tibialis anterior and peroneus longus, while the stimulating cathode was placed at the posterolateral border of the fibular neck. The skin temperature was maintained at or above 32 degrees C in the lateral surface of the proximal shin. In normal subjects, 81 deep and superficial peroneal nerves were tested to establish reference values. The latencies to the tibialis anterior and peroneus longus were 2.5 +/- 0.3 (range, 2-3) ms and 2.6 +/- 0.2 (range, 1.9-3) ms, respectively. The amplitudes of compound muscle action potential for deep and superficial peroneal nerves were 6.2 +/- 1.3 (range, 3.6-9.3) and 6.2 +/- 1.7 (range, 3.4-10.6) mV, respectively. Also, 17 adult onset diabetic patients were tested for comparison. We concluded that this alternative test to the conventional methods is accessible for electrophysiologic evaluation of peroneal neuropathy.

Action Potentials↗
PubMedDate not supplied

Amyotrophic lateral sclerosis. Successful treatment of mucous plugging by mechanical insufflation-exsufflation.

Bronchial mucous plugging is the main precipitating factor of acute respiratory failure for patients with neuromuscular disease. Manually assisted coughing and mechanical insufflation-exsufflation can effectively eliminate airway secretions without resorting to tracheal intubation provided that bulbar muscle function is sufficient to permit assisted peak cough flows of 160 l/min or greater. We now report successful use of mechanical insufflation-exsufflation to prevent acute respiratory failure for a patient with amyotrophic lateral sclerosis with no measurable peak cough flow.

Aged↗
PubMedDate not supplied

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.

Analysis of Variance↗
PubMedDate not supplied

Kinematic analysis of patients with spinal muscular atrophy during spontaneous breathing and mechanical ventilation.

Patients with infantile spinal muscular atrophy develop pectus excavatum along with a severe restrictive syndrome as a result of failure to expand the upper chest wall and lungs because of intercostal muscle weakness. By using an automatic motion analyzer to provide three-dimensional computer analyses of images sampled at 25 Hz, 9 spinal muscular atrophy Type II patients and 13 controls underwent kinematic analysis of thoracoabdominal movements partitioned into the upper thorax, lower thorax, and abdominal volume compartments. The analyses were performed during spontaneous breathing for the controls and during spontaneous breathing and while using mechanically assisted ventilation for the patients. Vital capacity, maximum inspiratory pressures, and nocturnal oxyhemoglobin saturation and transcutaneous carbon dioxide tensions were also measured for the patients. The kinematic data demonstrated a paradoxical ventilatory pattern for the spontaneously breathing SMA patients with the following inspiratory volume changes: upper thorax, -6.4+/-9.6%; lower thorax, 7.3+/-15.8%; abdominal, 99.1+/-21.3%. During mechanical ventilation, the compartmental volume changes were as follows: upper thorax, 13.5+/-6%; lower thorax, 13.7+/-7.9%; abdominal, 72.7+/-9.3%. This kinematic pattern is comparable with that seen in spontaneously breathing normal subjects. We conclude that mechanical ventilation can normalize kinematic volume changes during alveolar ventilation and that this might help deter loss of thoracic compliance caused by the chronic hypoventilation of the upper thoracic compartments. Kinematic analysis may be helpful for choosing the ventilation parameters to optimize therapeutic benefits.

Biomechanical Phenomena↗
PubMedDate not supplied

Kyphoscoliosis ventilatory insufficiency: noninvasive management outcomes.

OBJECTIVE: To determine the effects on symptoms, pulmonary function, sleep, and other clinical variables of treating kyphoscoliosis-associated chronic alveolar hypoventilation with nocturnal nasal ventilation. DESIGN: Sixteen patients with kyphoscoliosis were treated with nocturnal nasal ventilation delivered by volume-cycled (seven patients) and pressure-cycled (nine patients) ventilators. Dyspnea, morning headaches, fatigue, hypersomnolence, and perceived sleep quality were assessed. RESULTS: All pretreatment symptoms improved significantly with nasal ventilation. Likewise, PaO2 (mm Hg), PaO2/FlO2, PaCO2 (mm Hg), pH, and forced vital capacity (in milliliters and as a percentage of predicted normal) significantly improved with treatment. Maximum inspiratory pressures and maximum expiratory pressures also significantly increased. Tidal volumes increased significantly and breathing frequency decreased (not significant). Although perceived sleep quality improved, as well as sleep oxyhemoglobin saturation, there was no significant change in sleep architecture. Hospitalization days for respiratory difficulties also decreased from 10.9 +/- 13.3 days in the 6 mo before intermittent positive-pressure ventilation to 0 days during the first 6 mo of treatment. CONCLUSIONS: Although not apparently affecting sleep architecture, nocturnal nasal ventilation can significantly improve nocturnal and daytime blood gases, pulmonary function, and symptoms of hypoventilation for patients with severe kyphoscoliosis.

Adult↗
PubMedDate not supplied

Maximum insufflation capacity: vital capacity and cough flows in neuromuscular disease.

OBJECTIVE: To investigate the relationships between vital capacity (VC), maximum insufflation capacity (MIC), and both unassisted and assisted peak cough flows (PCFs). DESIGN: The 108 patients were divided into two groups, those whose MICs were greater than their VCs (group 1) and those whose MICs could not exceed their VCs (MIC = VC, or group 2). RESULTS: The MIC correlated positively with the VC for group 1 patients, but the percent increase in MIC correlated negatively with VC. Both VC and MIC correlated significantly with both unassisted and assisted PCF, respectively. Assisting the cough increased the PCF of 37 patients over a previously defined critical level of 2.7 L/sec. The MIC VC difference and percent increase in MIC also correlated significantly with the difference between unassisted and assisted PCF. Although the group 2 patients did not have true cough flows because of inability to close the glottis, their peak expiratory flows were significantly less than the unassisted and assisted PCF of the group 1 patients. CONCLUSIONS: The greater the MIC VC difference, the greater the PCF, and, thereby, the ability to expel airway mucus and avert respiratory complications. The lower the VC, the greater the percent increase in MIC and the greater the percent increase in assisted PCF. Maximal insufflations are extremely important to increase PCF for patients with neuromuscular conditions who have VCs of < 1500 ml.

Adult↗
PubMedDate not supplied

A study of thyrotropin-releasing hormone for the treatment of spinal muscular atrophy: a preliminary report.

OBJECTIVE: To determine whether thyrotropin-releasing hormone (TRH) can increase muscle strength in children with spinal muscular atrophy types 2 and 3. DESIGN: A randomized, double-blinded, controlled, 5-wk drug trial of six subjects and three controls. Subjects and controls ranged from 4 to 8 yr of age and were randomly assigned to treatment and placebo groups in a ratio of 2:1. TRH (protirelin) or placebo was delivered intravenously through percutaneous intravenous catheters at a dose of 0.1 mg/kg (in 50 ml of normal saline) for a total of 29 days. Patients were evaluated using electromyography and handheld dynamometry of the deltoids, biceps, triceps, wrist extensors, hip flexors, quadriceps, hamstrings, and grip strength before and immediately after 5 wk of treatment. A unidirectional t test was used to compare mean values. RESULTS: Dynamometry improved significantly only for the six treated subjects (P < 0.02). Peroneal nerve conduction velocities were significantly faster in the treatment group (paired t test, P = 0.036). The parents of the treated children also provided anecdotal evidence of improvements in function. Improvements lasted 6-12 mo. CONCLUSIONS: TRH may be a useful treatment for spinal muscular atrophy. A larger, crossover design group comparison study is warranted.

Action Potentials↗
PubMedDate not supplied

Mechanical exsufflation, noninvasive ventilation, and new strategies for pulmonary rehabilitation and sleep disordered breathing.

Manual and mechanical exsufflation are important but underutilized ways to clear airway secretions. These methods are especially useful when used in concert with noninvasive intermittent positive airway pressure ventilatory assistance to facilitate extubation and ventilator weaning. This can be used as much as 24 hours a day as an alternative to tracheostomy ventilation or body ventilator use for patients with paralytic restrictive ventilatory insufficiency. These techniques expedite community management of ventilator assisted individuals by avoiding tracheostomy and need for invasive suctioning and ongoing wound care. For these techniques to be effective and to prevent further suppression of ventilatory drive, supplemental oxygen administration must be avoided unless pO2 is less than 60 mm Hg despite normalization of pCO2. Custom molded interfaces for the delivery of noninvasive intermittent positive airway pressure ventilatory assistance can also be used to facilitate the delivery of variable inspiratory expiratory positive airway pressure for patients with obstructive sleep apnea. Noninvasive intermittent positive airway pressure ventilatory assistance or body ventilator use can rest the respiratory muscles of patients with advanced chronic obstructive pulmonary disease. This and pulmonary rehabilitation programs geared to exercise reconditioning are therapeutic options that significantly improve the quality of life of these patients. For both paralytic restrictive and obstructive pulmonary patients, these techniques decrease cost and frequency of hospitalizations.

Humans↗
PubMedDate not supplied

Custom-fabricated interfaces for intermittent positive pressure ventilation.

Patients with chronic respiratory insufficiency resulting from paralysis of respiratory muscles have been supported most commonly by mechanical ventilation via a tracheostomy. Acute and long-term morbidity and mortality have been associated with tracheostomy. Noninvasive alternatives for providing mechanical respiratory support include negative pressure "body ventilators" and positive pressure ventilation via a nasal, oral, or oronasal interface. Intermittent positive pressure ventilation via the nose, mouth, or oronasal combination is effective and convenient for the majority of patients when the interface is sufficiently airtight and comfortable to permit effective long-term use. Construction of custom-fabricated interfaces for the administration of assisted ventilation is presented. These interfaces provide better fit for greater interface seal and comfort than commercial masks. They allow more patients to benefit from assisted positive pressure ventilation in the home without resorting to a tracheostomy.

Equipment Design↗
PubMedDate not supplied

A management trial for Duchenne cardiomyopathy.

The physiatrist can now be instrumental in prolonging the survival of individuals with neuromuscular disease by using respiratory muscle aids. As a result, morbidity and mortality from cardiomyopathy are likely to increase for patients with generalized myopathies. One hundred consecutive patients with dystrophin-deficient muscular dystrophy and a mean age of 17.2 yr (range, 5-41) satisfied criteria for having dilated cardiomyopathy (DCM) and received digitalis and diuretics. Nine of the 14 patients were symptom-free, despite left ventricular ejection fractions (LVEFs) of 25-40%. The five patients with symptomatic heart failure had severe ventricular dilatation, with LVEFs < 25%. Two of the five patients died of heart failure within 1 yr. For the remaining three patients, we evaluated the addition of the angiotensin-converting enzyme (ACE) inhibitor enalapril and, subsequently, the use of beta-blockers to the therapeutic regimen. Addition of these medications, never before attempted in the management of cardiomyopathy associated with generalized myopathic disease, complemented each other in relieving symptoms and reversing signs of congestive heart failure and DCM. We conclude that the combination of ACE inhibitor and beta-blocker deserves further exploration for inclusion in any management regimen for the treatment of muscular dystrophy-associated cardiomyopathy.

Adolescent↗