Pulmonary Function in Diaphragmatic Paralysis

Factors Affecting Lymphatic Absorption in Chinese Patients on Continuous Ambulatory Peritoneal Dialysis (CAPD)

The pathways and physiology of lymph absorption (LA) from the peritoneal cavity are well documented; however, much uncertainty still exists as to the various clinical and demographic factors affecting LA. We studied LA measured by the albumin instillation method, in adult Chinese CAPD patients, and showed that it was independent of age, sex, body surface area, duration of dialysis, intrinsic renal disease, use of intraperitoneal drugs (heparin/antibiotics/deferroxamine) and frequency of past bacterial peritonitis. High lymph absorbers had a relatively highertranscapillary cumulative ultrafiltration than low lymph absorbers. An enhanced LA was associated with a high initial intraperitoneal volume. Assessment of diaphragmatic strength by the decrement in vital capacity on changing from an erect to a supine position failed to distinguish patients with high and low LA.

Exercise testing in patients with diaphragm paresis

PURPOSE

Diaphragm paresis (DP) is characterized by abnormalities of respiratory muscle function. However, the impact of DP on exercise capacity is not well known. This study was performed to assess exercise tolerance in patients with DP and to determine whether inspiratory muscle function was related to exercise capacity, ventilatory pattern and cardiovascular function during exercise.

METHODS

This retrospective study included patients with DP who underwent both diaphragmatic force measurements, and cardiopulmonary exercise testing (CPET).

RESULTS

Fourteen patients were included. Dyspnea was the main symptom limiting exertion (86%). Exercise capacity was slightly reduced (median VO2peak: 80% [74.5%-90.5%]), mostly due to ventilatory limitation. Diaphragm and overall inspiratory muscle function were correlated with exercise ventilation. Moreover, overall inspiratory muscle function was related with oxygen consumption (r=0.61) and maximal workload (r=0.68).

CONCLUSIONS

DP decreases aerobic capacity due to ventilatory limitation. Diaphragm function is correlated with exercise ventilation whereas overall inspiratory muscle function is correlated with both exercise capacity and ventilation suggesting the importance of the accessory inspiratory muscles during exercise for patients with DP. Further larger prospective studies are needed to confirm these results.

Best Approach and Benefit of Plication for Paralyzed Diaphragm

Diaphragmatic eventration and diaphragmatic paralysis are 2 entities with different etiology and pathology, and are often clinically indistinguishable. When symptomatic, their treatment is the same, with the objective to reduce the dysfunctional cephalad excursion of the diaphragm during inspiration. This can be achieved with diaphragmatic plication through the thorax or the abdomen with either open or minimally invasive techniques. We prefer the laparoscopic approach, due to its easy access to the diaphragm and to avoid pain associated with intercostal incisions and instrument use. Short-term and long-term results are excellent with this technique.

The role of the thoracic diaphragm

The thoracic diaphragm is the principal muscle of inspiration and is present only in placentalia. Its dome-shaped musculo-fibrous septum separates the thorax from the abdominal cavity.

Diaphragm plication for eventration or paralysis: a review of the literature

Although etiology and pathology of symptomatic diaphragm paralysis and eventration are distinct, their treatments are the same: to reduce dysfunctional caudal excursion of the diaphragm during inspiration by plication. Minimally invasive diaphragm plication techniques have emerged as equally effective and less morbid alternatives to open plication. This review focuses on the etiology, pathophysiology, diagnosis, and treatment of diaphragmatic eventration or paralysis in adults.

Diaphragmatic eventration

Symptomatic diaphragmatic eventration is an uncommon condition and is sometimes impossible to distinguish clinically from paralysis. Patients who are asymptomatic require no treatment; patients who are symptomatic benefit significantly from diaphragm plication. The choice of plication approach is dependent upon the expertise of the surgeon.

Mapping of autosomal recessive chronic distal spinal muscular atrophy to chromosome 11q13

Distal spinal muscular atrophy is a heterogeneous group of neuromuscular disorders caused by progressive anterior horn cell degeneration and characterized by progressive motor weakness and muscular atrophy, predominantly in the distal parts of the limbs. Here we report on chronic autosomal recessive distal spinal muscular atrophy in a large, inbred family with onset at various ages. Because this condition had some of the same clinical features as spinal muscular atrophy with respiratory distress, we tested the disease gene for linkage to chromosome 11q and mapped the disease locus to chromosome 11q13 in the genetic interval that included the spinal muscular atrophy with respiratory distress gene (D11S1889-D11S1321, Z(max) = 4.59 at theta = 0 at locus D11S4136). The sequencing of IGHMBP2, the human homologue of the mouse neuromuscular degeneration gene (nmd) that accounts for spinal muscular atrophy with respiratory distress, failed to detect any mutation in our chronic distal spinal muscular atrophy patients, suggesting that spinal muscular atrophy with respiratory distress and chronic distal spinal muscular atrophy are caused by distinct genes located in the same chromosomal region. In addition, the high intrafamilial variability in age at onset raises the question of whether nonallelic modifying genes could be involved in chronic distal spinal muscular atrophy.

Assessment of corticodiaphragmatic pathway and pulmonary function in acute ischemic stroke patients

The aims of this study were to investigate the effect of stroke on the corticodiaphragmatic pathway and to clarify the relationships between neurophysiological data and degree of motor disability, site of infarction in CT scan, diaphragmatic excursion, blood gases and pulmonary function in stroke patients. The corticodiaphragmatic pathway was assessed using magnetic stimulation of the scalp sites and cervical roots. The study included 34 sequentially selected patients out of 250 patients with acute ischemic stroke. Twenty-five (age and sex matched) volunteers served as controls. Sixteen patients had cortical infarction, thirteen had subcortical infarction and five had both cortical and subcortical infarction. The mean Scandinavian Stroke Scale was 32.2. Decreased diaphragmatic excursion was observed in 41% of the patients. Twenty-four patients (70.5%) had abnormal magnetic evoked potentials (MEPs) of the affected hemisphere. In five patients MEPs were unelicitable from the affected hemisphere. The remaining nineteen patients had abnormal values of both cortical latency and central conduction time (CCT). Cortical latency, CCT, amplitude of compound muscle action potentials (CMAPs) and excitability threshold of the affected hemisphere were significantly altered compared to both the unaffected hemisphere and the control group. The patients with hemiplegia had a greater degree of hypoxia, hypocapnia and decreased serum bicarbonate level compared to the control group. Additionally, hemiplegic patients had a different degree of respiratory dysfunction. A statistically significant association was found between neurophysiological data and disability score, diaphragmatic excursion, site of infarction in CT scan and degree of respiratory dysfunction. Central diaphragmatic impairment may occur in acute stroke and could contribute to the occurrence of hypoxia in those patients.

Weaning from mechanical ventilation

Use of mechanical ventilation is associated with several major complications despite its lifesaving potential. Timely discontinuation of mechanical ventilation is critical to control of duration of intensive care unit stay and reduction of complications associated with mechanical ventilation. Difficulty in discontinuation (or weaning) of patients from mechanical ventilatory support is in part attributable to inadequate understanding of the mechanisms responsible for unsuccessful outcome and a lack of guidelines regarding the optimal approach to the process of discontinuation of mechanical ventilation. For the first time, results from prospective, randomized, multicenter trials are available comparing common means of discontinuation of mechanical ventilation. In addition, the physiologic basis for a weaning strategy in mechanical ventilation is also coming into better focus. Two recent trials of weaning suggest different optimal modes, one favoring T-piece trials and the other supporting the use of pressure support ventilation. In either case, the above weaning techniques appear to be superior to intermittent mandatory ventilation in separating patients from mechanical ventilatory support. Based on available clinical trials, pressure support ventilation or T-piece trials appear to be the preferred methods for discontinuation of mechanical ventilatory support. A method using a simple T-piece trial technique is described.

Diaphragmatic plication for unilateral diaphragmatic paralysis: a 10-year experience

Unilateral paralysis of the diaphragm due to nonmalignant disease is an uncommon disorder previously thought to have benign implications. Some patients, however, experience dyspnea and orthopnea with impairment of pulmonary function. Unilateral diaphragmatic plication was performed on 17 patients (16 men and 1 woman with a mean age of 53.7 years [range, 28 to 74 years]) during the last 10 years. Preoperatively each patient was shown to have paradoxical movement of the paralyzed diaphragm on sniffing and to have a reduction in forced vital capacity and lung volumes. These reductions were greater when the patient was in the supine position. All patients had moderate hypoxemia (mean arterial oxygen tension, 73.1 +/- 10.9 mm Hg). Plication was performed by imbricating the diaphragm in layers through a thoracotomy incision. After plication, all patients showed both subjective and objective improvement. Six patients were reassessed 5 or more years after plication (range, 5 to 7 years), and the improvement was maintained. Diaphragmatic plication is a safe and effective procedure for adult patients with dyspnea due to unilateral diaphragmatic paralysis; furthermore, the initial improvement is maintained.

Diaphragmatic weakness and paralysis

Diaphragmatic weakness implies a decrease in the strength of the diaphragm. Diaphragmatic paralysis is an extreme form of diaphragmatic weakness. Diaphragmatic paralysis is an uncommon clinical problem while diaphragmatic weakness, although uncommon, is probably frequently unrecognized because appropriate tests to detect its presence are not performed. Weakness of the diaphragm can result from abnormalities at any site along its neuromuscular axis, although it most frequently arises from diseases in the phrenic nerves or from myopathies affecting the diaphragm itself. Presence of diaphragmatic weakness may be suspected from the complaint of dyspnea (particularly on exertion) or orthopnea; the presence of rapid, shallow breathing or, more importantly, paradoxical inward motion of the abdomen during inspiration on physical examination; a restrictive pattern on lung function testing; an elevated hemidiaphragm on chest radiograph; paradoxical upward movement of 1 hemidiaphragm during fluoroscopic imaging; or reductions in maximal static inspiratory pressure. The diagnosis of diaphragmatic weakness is confirmed, however, by a reduction in maximal static transdiaphragmatic pressure (Pdimax). The diagnosis of diaphragmatic paralysis is confirmed by the absence of a compound diaphragm action potential on phrenic nerve stimulation. There are many causes of diaphragmatic weakness and paralysis. In this review we outline an approach we have found useful in attempting to determine a specific cause. Most frequently the cause is either a phrenic neuropathy or diaphragmatic myopathy. Often the neuropathy or myopathy affects other nerves or muscles that can be more easily investigated to determine the specific pathologic basis, and, by association, it is presumed that the diaphragmatic weakness or paralysis is secondary to the same disease process.

[Diaphragmatic paralysis disclosed by acute respiratory failure. Apropos of a case of amyotrophic lateral sclerosis and review of the literature]

A case of acute respiratory failure revealing amyotrophic lateral sclerosis is reported. The other neurological diseases with diaphragmatic paralysis are recalled.

Diaphragmatic dysfunction in siblings with hereditary motor and sensory neuropathy (Charcot-Marie-Tooth disease)

Hereditary motor and sensory neuropathy (Charcot-Marie-Tooth disease) is characterized by chronic degeneration of peripheral nerves and roots, resulting in distal muscle atrophy, beginning in the feet and legs and later involving the hands. The association of this disease with diaphragmatic dysfunction has not been reported. We studied a patient with hereditary motor and sensory neuropathy type 1 (Charcot-Marie-Tooth disease) and type 2 diabetes mellitus who had severe diaphragmatic impairment. Some of the clinical findings are similar to the sleep apnea syndrome, which could lead to incorrect diagnosis and delay in the administration of appropriate therapy. Transdiaphragmatic pressure studies on the subject's brother, who also has Charcot-Marie-Tooth disease and type 2 diabetes mellitus, revealed subclinical impairment of diaphragmatic function. These findings suggest that phrenic nerve involvement may be part of the spectrum of polyneuropathy in Charcot-Marie-Tooth disease in association with diabetes mellitus.

Electrophysiologic evaluation of phrenic nerves in severe respiratory insufficiency requiring mechanical ventilation

Diaphragmatic paralysis in patients with respiratory insufficiency compounds the problems in the management. In the presence of lower lobe atelectasis, pleural effusion, or a patient's poor respiratory effort, fluoroscopic examination is often not a reliable way to diagnose diaphragmatic paralysis. We observed that transcutaneous phrenic nerve stimulation in the neck and recording the diaphragmatic potentials from electrodes placed on the lower part of the chest is a simple, reliable, and noninvasive technique to diagnose diaphragmatic dysfunction at the bedside in critically ill patients. In 14 postoperative patients and one with cervical spinal cord injury with respiratory failure, we found ten patients who showed phrenic nerve dysfunction. Besides diagnostic utility, the electrophysiologic evaluation of phrenic-diaphragmatic function provides critical information needed for therapy.

Diaphragmatic myasthenia in mother and child

A 28 year old patient with ocular myasthenia for 2 y gave birth to a baby with diaphragmatic weakness. Following delivery the mother developed severe weakness of the diaphragm and required assisted ventilation. The baby recovered spontaneously and the mother responded to treatment with plasma exchange and immunosuppression. Neither mother nor baby responded to anticholinergic drugs and in neither serum were acetyl choline receptor antibodies detected.

The use of operant conditioning techniques in the respiratory rehabilitation of the tetraplegic

This paper discusses the development of a pilot project in respiratory rehabilitation as part of the total rehabilitation of the tetraplegic and high paraplegic. The principles of neuromuscular exercise and of behaviouristic psychology introduce the subject of operant learning in the rehabilitation setting. Incentive spirometry is described as the basic element in the development of a respiratory rehabilitation programme. The preliminary results are analysed and a recommendation made that such a programme materially increases the respiratory function of the tetraplegic, and, not least, assists in his ability to combat intercurrent respiratory infection.

Bilateral diaphragmatic paralysis with hypercapnic respiratory failure. A physiologic assessment

Bilateral diaphragmatic paralysis was suspected in a patient presenting with hypercapnic respiratory failure who exhibited paradoxic (i.e., inward) abdominal movement on inspiration during tidal breathing in the supine posture; no paradoxic abdominal motion was observed at the bedside with the patient upright. Transdiaphragmatic pressure measurements established the diagnosis of diaphragmatic paralysis, although 20 cm H2O pressure developed across the diaphragm during the latter part of a forced expiration, presumably due to the development of passive tension in the diaphragm as it was stretched near residual volume. Analysis of the relative motion of the rib cage and abdomen during breathing by the use of magnetometers confirmed the presence of abdominal paradox throughout the breathing cycle when the patient was supine, and established that paradoxic motion of the abdomen also occurred when the patient was in the erect posture but only in the latter half of inspiration. Our findings confirm that the use of transdiaphragmatic pressure measurements and magnetometry will help to quantify diaphragmatic function, that passive tension develops in the paralyzed diaphragm near residual volume and should not be confused with active contraction, and that paradoxic motion of the abdomen may be masked from the clinician when the patient is erect.

Diaphragm function and lung involvement in systemic lupus erythematosus

Lung involvement was assessed in 30 consecutive patients with systemic lupus erythematosus (SLE), not selected by respiratory symptoms. Pulmonary function tests revealed a higher rate of abnormality than either clinical history or radiography. The single breath carbon monoxide diffusing capacity was below 80 per cent of the predicted value in 24 patients (80 per cent), and a reduced total lung capacity was present in 13 (43 per cent). There was a weak correlation between the severity of the functional defect and disease activity, assessed antinuclear factor and DNA binding. No correlation was found with serum complement of Clq precipitation. Since pulmonary fibrosis in SLE is uncommon it cannot account for the high frequency of abnormal findings, and the pathogenesis of the functional changes is probably multifactorial. In seven of the patients with the smallest lung volumes, measurements of static pressure volume curves and of maximum respiratory pressures indicated extrapulmonary volume restriction. In five of these patients, diaphragm function was specifically assessed and found to be grossly abnormal in four. The inability of the diaphragm to generate normal pressure may be due to either severe weakness or immobility following extensive pleural adhesions. The well recognized syndrome of "shrinking lungs" and high "sluggish" diaphragms with clear lung fields on radiography is probably due to dysfunction of the diaphragm rather than to primary intrapulmonary pathology.

Acute supine respiratory failure due to bilateral diaphragmatic paralysis

This report documents the first known case of bilateral diaphragmatic paralysis following blunt trauma to the chest. The important role of diaphragmatic function in maintaining ventilation, particularly with the patient in the supine position, is illustrated by the reduced total lung capacity, functional residual capacity, and vital capacity. Severe hypoxemia with the patient in the supine position, was markedly improved by elevation of the patient to 30 degree and was further improved by sitting the patient upright. Following an initial period of acute respiratory failure, the patient was managed acceptably by maintaining an elevated position for sleeping until diaphragmatic function returned, about nine months after the injury.

Amyotrophic lateral sclerosis presenting with respiratory failure. Diaphragmatic paralysis and dependence on mechanical ventilation in two patients

Described are two patients whose initial symptom was acute respiratory failure requiring mechanical ventilation. Initially, the cause of the respiratory failure in each patient was obscure, but diaphragmatic paralysis was subsequently demonstrated fluoroscopically in each case. Further neurologic evaluation then supported the diagnosis of amyotrophic lateral sclerosis. Postmortem examination corroborated this diagnosis.

Cervical accessory respiratory muscle function in a patient with a high cervical cord lesion

The function of the accessory respiratory muscles (ARM) of the neck were studied in a quadriplegic patient suffering from a C2-3 lesion of the cervical spinal cord. Subtotal expiratory paralysis resulted in an essentially complete loss of expiratory reserve volume such that residual volume and functiona residual capacity were equal (RV=FRC). Tidal volume and vital capacity were severely reduced. Being extrinsic to the chest, the ARM of the neck functioned independently of changes in thoracic gas volume; however, their performance appeared posture-dependent, and was less efficient in the sitting position. Despite the fact that the ARM preferentially expanded the upper part of the ribcage, significant V/Q mismatch did not seem to occur. Voluntary use of glossopharynegeal breathing (GPB) greatly enhanced the patient's ventilatory capability. Flow volume data during GPB documented the efficiency of the glossopharyngeal muscles, which function as a positive pressure pump to force air into the lungs.

Regional lung function in unilateral diaphragmatic paralysis

Radioactive xenon-133 was used to study the regional lung function of five patients with unilateral diaphragmatic paralysis unassociated with intrathoracic disease. All patients showed a reduction in total lung capacity to which the affected side contributed an average of 37%. There was a decrease in the amount of inhaled xenon and a lesser decrease in the amount of injected xenon reaching the lung base on the paralysed side.The distribution in the opposite lung did not differ significantly from that found in normal subjects although the proportion of inhaled xenon reaching the lung base was rather less than in the normal group. The washout of injected xenon was normal except for slight impairment at the lung base on the paralysed side in one patient and at both bases in another.