The recognition and management of respiratory insufficiency in neuromuscular disease

The recognition and management of respiratory insufficiency in neuromuscular disease

J Chron Dis Vol. 35. pp. 497 to 500, 1982 0021-9681/82/[email protected] Copyright 0 1982Pergamon Press Ltd Printed in Great Britain. All rights rese...

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J Chron Dis Vol. 35. pp. 497 to 500, 1982

0021-9681/82/[email protected] Copyright 0 1982Pergamon Press Ltd

Printed in Great Britain. All rights reserved

Editorial THE RECOGNITION AND MANAGEMENT RESPIRATORY INSUFFICIENCY IN NEUROMUSCULAR DISEASE* ROBERT C. GRIGGS

and

KATHARINE

OF

M. DONOHOE

Departments of Neurology, Medicine and Pediatrics, University of Rochester School of Medicine and Dentistry and School of Nursing, Rochester, NY 14642, U.S.A. (Received 20 August 1981)

progressive neuromuscular diseases such as amyotrophic lateral sclerosis, spinal muscular atrophy and muscular dystrophy can all eventuate in respiratory muscle weakness and respiratory failure. The methodology for recognition, prevention and treatment of respiratory failure from muscle weakness is now widely available. It is, therefore, imperative that ventilatory function be monitored regularly and frequently in patients with neuromuscular disease. Abrupt deterioration in function usually indicates a coincidental treatable process and is almost always reversible. Those unfamiliar with the patient or his neuromuscular disease are often quick to assume incorrectly that respiratory failure is from muscle weakness. Those disorders commonly associated with respiratory muscle weakness and failure are listed in the Table 1. Respiratory failure may occur prior to recognition that a neuromuscular disease is present (see Table 1). Amyotrophic lateral sclerosis is particularly noteworthy in this respect, since selective involvement of diaphragmatic motor neurons often results in unrecognized diaphragmatic paralysis and severe, supine hypo-

THE SEVERE,

*Supported in part by grants from the Muscular Dystrophy Association and U.S. Public Health Service Grant No. RR 00044 from the Division of Research Resources of the National Institutes of Health.

TABLE1. CHRONIC NEUROMUSCULAR DISEASES CAUSING RESPIRATORY INSUFFICIENCY Anterior horn cell disease

Peripheral neuropathy Neuromuscular junction disorders Myopathy

Amyotrophic lateral sclerosis* Spinal muscular atrophy (especially Werdnig-Hoffman disease); late progression of poliomyelitis Chronic relapsing polyneuritist Myasthenia gravis * , Eaton-Lambert syndrome* Muscular dystrophies: Duchenne dystrophy (including ‘benign’ forms); myotonic dystrophy*; limb-girdle dystrophy; facioscapulo-humeral dystrophyt: scapuloperoneal dystrophy Metabolic disorders: Acid maltase deficiency* ; carnitine deficiency Congenital myopathies: Centronuclear myopathy; nemaline myopathyi Polymyositis/dermatomyositisi

*Those which may present with respiratory involvement failure; tRarely produce respiratory insufficiency. <.n.357 *

497

and unexplained

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ROBERTC. GRIGGS and KATHARINEM. D~NOHOE

ventilation [l, 23. Such patients may complain of dyspnea or fatigue but may also develop respiratory failure abruptly and without warning. Signs of nocturnal hypoxia and hypercarbia may be present and include early morning headache, nocturnal myoclonus, confusion, or erythremia. Routine pulmonary function tests may be virtually normal in such patients; studies repeated with the patient in the supine position may show marked abnormalities [2]. In our experience, unrecognized amyotrophic lateral sclerosis has been present in most cases of ‘idiopathic diaphragmatic paralysis’ [3]. Recognition Respiratory muscle involvement may be detected clinically by subjective assessment of cough effectiveness, by quantitation of the patient’s ability to count on a single breath, and by percussion and ausculation for diaphragmatic movement, Patients should be observed while supine and sitting. The presence of coincident obstructive lung disease may be suggested by auscultation of the chest during forced expiration-listening for wheezes and timing the duration of expiration. Pulmonary function should be measured sequentially in patients with neuromuscular disease. Forced vital capacity (FVC), maximum expiratory flow rate (MEFR), maximum voluntary ventilation (MVV), maximum expiratory pressure (MEP) and a flow-volume loop or curve should be obtained routinely. Static pressures, particularly MEP, are especially useful in patients with neuromuscular disease [4,5]. MEP is the most sensitive, readily available indicator of respiratory muscle weakness. A normal MEP in a patient with neuromuscular disease indicates that weakness is not the cause of respiratory symptoms. Conversely, many patients with significant respiratory muscle weakness may have a normal FVC but a reduced MEP. Portable spirometers are useful for rapid assessment of respiratory function in the office and at the bedside. Certain spirometers (e.g. the [email protected]) are unsatisfactory for use in patients with neuromuscular disease [S], perhaps because of a high resistance to flow [6]. Electronic spirometers (e.g. the [email protected]) are of low resistance and are accurate in patients with neuromuscular disease [S, 73. It is preferable to have a low resistance spirometer that provides a flow-volume curve. The chest roentgenogram is helpful in detecting acute changes such as atelectasis, pneumothorax or heart failure. It is necessary to have a baseline roentgenogram to prevent misinterpretation of poor inspiratory effort. Blood gases are seldom abnormal in restrictive lung disease due to neuromuscular disease until weakness is severe [S, 91 but may be helpful in recognizing coincidental obstructive lung disease (COPD) or congestive heart failure. Prevention Patients with a 50% reduction in FVC and all patients with impaired cough merit prophylactic measures. Influenza virus (yearly) and pneumococcal (once only) vaccines as well as prophylactic antibiotics for upper respiratory infections, while not of documented benefit, seem justified. It is also our impression that breathing exercises using incentive spirometry or blow bottles may help prevent atelectasis and infection. Patients with diminished cough and difficulty clearing secretions benefit from postural drainage and suction equipment. These patients are at risk for illness other than their neuromuscular disease and should receive appropriate preventive care, with emphasis on detection of treatable coincidental disease. COPD is the most frequently encountered. Acute respiratory failure When the respiratory function of a patient with neuromuscular disease deteriorates abruptly for the first time, a superimposed illness is almost invariably present [3, lo]. In our experience with over 60 such patients, a remediable disorder has been detected and the patient returned in most instances to independent respiratory status. The one exception is amyotrophic lateral sclerosis where the rapid progression of the disease often results in a respirator-dependent patient. Otherwise, we have successfully weaned

Editorial

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patients from respirator support. The most common causes of respiratory failure are pneumonitis, atelectasis, and aspiration. A knowledge of pulmonary function tests prior to the abrupt onset of respiratory failure should guide the clinician in choosing therapeutic options. An exacerbation of COPD, the appearance of congestive heart failure, or a pneumothorax may also lead the unwary to conclude that ‘terminal respiratory failure’ has developed when it indeed has not. In one of our patients an episode of marijuanainduced bronchitis simulated end-stage weakness. Discovery of treatable factors may obviate the need for respiratory support even in patients whose FVC is below 500~~. Obesity, COPD, congestive heart failure, unsuspected aspiration and supine hypoventilation from diaphragmatic weakness, may all respond to appropriate treatment. Aminophylline, useful in COPD, may also increase diaphragmatic strength [ll]. Patients with myasthenia gravis, Eaton-Lambert syndrome, chronic inflammatory neuropathies and polymyositis may recover with specific therapy. Chronic respiratory

support

Patients with acute respiratory failure from amyotrophic lateral sclerosis and those with recurrent respiratory failure in other neuromuscular disease may prove to be respirator-dependent. Patients with other neuromuscular diseases may also gradually develop respiratory insufficiency. A number of therapeutic options are available for such patients. Positive pressure respiratory support requires a tracheostomy but is compatible with prolonged home support of ventilation. A tracheostomy is often performed during acute respiratory failure and may need to be done electively for patients who aspirate or are unable to cough effectively. Speech may be restored by using ‘trach talk’ with a cuffed tube or a non-cuffed fenestrated tube. Positive pressure ventilators are usually cumbersome and technically difficult to operate. As these patients rarely need oxygen, a system should be prescribed that is easily adapted for home use. An example of such a system is the CAM [email protected], which is portable and can run on AC outlet power or an internal battery. Negative pressure and expiratory assist devices have been available for over three decades [12,13] but have only recently been widely utilized in patients with chronic neuromuscular disease. Indeed a recent text on treatment of respiratory dysfunction in neurologic disorders does not discuss their use [9]. The cuirass [12], plastic wrap (‘raincoat’) [14] and tank (‘iron-lung’) [15] all aid ventilation by producing negative pressure. The pneumobelt [16] and rocking bed [13] provide expiratory assistance. The cuirass and pneumobelt can be adapted for wheelchair and automobile use, permitting a mobile life-style. Cuirass shells can be custom-made to fit patients with severe chest deformities

r-171. The successful management of patients using prolonged respiratory support demands a team of professionals that at our institution includes physicians, nurse-clinician, respiratory therapist and visiting nurses-all willing to attend the patient at home. A supportive family, willing to assume a major portion of the patient’s management is also essential. Which patients

should receive

respiratory

support?

For some patients this decision has been made by instituting respiratory support prior to diagnosis. The decision to withhold or provide long-term respiratory support in patients with insidiously developing respiratory failure is complex and individual [18]. The decision should, however, be made before the emergency setting and involve the patient, family and medical team. Otherwise, those least familiar with the patient, such as emergency room staff, may dominate the decision process. Such judgements were once dictated by phycians, but are now under the purview of the patient [19] with a developing literature available for patients and their families permitting intelligent decisions [20]. More patients now elect such support than we might have expected. REFERENCES 1.

Newsom-Davis J, Goldman Med 45:87, 1976

M, Lohn

L, Casson

M: Diaphragm

function

and alveolar

ventilation.

Q J

500 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15.

16. 17. 18. 19. 20.

ROBERTC. GRIGGSand KATHARINEM. DONOHOE Sivak ED, Streib EW: Management of hypoventilation of motor neuron disease presenting with resplratory insufficiency. Ann Neurol 7:188-191, 1980 Griggs RC, Donohoe KM, Goldblatt D: Management of respiratory insufficiency in neuromuscular disease. (Submitted for publication). Goldstein RL, Hyde RW, Lapham LW, Gazioglu K, dePapp, ZG: Peripheral neuropathy presenting with respiratory insufficiency as the primary complaint. Am J Med 56:443-446, 1974 Griggs RC, Donohoe KM, Utell MJ, Goldblatt D, Moxley RT: Evaluation of pulmonary function in neuromuscular disease. Arch Neurol 38: 9-12, 1981 Gardner kM, Hankinson JL, West BJ: Evaluating commercially available spirometers. Am Rev Resp Dis 121:73-82, 1980 Florence JM, Brooke MH, Carrol JE: Evaluation of the child with muscular weakness. Orthop Clin North Am 9 :409-430, 1978 Fallat RJ, Jewitt B, Bass M, et al: Spirometry in amyotrophic lateral sclerosis. Arch Neurol 36:74-80, 1979 Ringel SP, Carroli JE: Respiratory complications of neuromuscular disease. In Respiratory Dysfunction in Neurologic Disease, Weiner WJ (Ed), New York: Futura, 1980 O’Donohue WJ, Baker JP, Bell GM, Muren 0, Parker CL, Patterson JL: Respiratory failure in neuromuscular disease: Mangement in a respiratory intensive care unit. JAMA 235: 733-735, 1976 Aubier M, De Troyer A, Sampson M, Macklem PT, Roussos C: Aminophylline improves diaphragmatic contractility. N Engl J Med 305:249-252, 1981 Plum F, Lukas DS: Evaluation of ciurass respirator in acute poliomyelitis with respiratory insufficiency. Am J Med Sci 221: 417-424, 1951 Plum F, Whedon GD: The rapid-rocking bed: Its effect on the ventilation of poliomyelitis patients with respiratory paralysis. N Engl J Med 245:235-241, 1951 Alexander MA, Johnson EW, Petty J, Stauch D: Mechanical ventilation of patients with late stage Duchenne muscular dystrophy: Management in the home. Arch Phys Med Rehahil 60:289-292, 1979 Griggs RC: Respiratory problems in amyotrophic lateral sclerosis. Commentary. In The Diagnosis and Treatment of Amyotrophic Lateral Sclerosis. Mulder DW (Ed). Boston: Houghton-Mifflin, 1979, pp. 316318 Adamson JP, Lewis L, Stein JD: Application of abdominal pressure for artificial respiration. JAMA 69:153-157, 1959 Wiers PW, Le Coultre R, Dallinga OT, Van Dijl W, Meinesz AF, Sluiter HJ: Cuirass respirator treatment of chronic respiratory failure in scoliotic patients. Thorax 32:221-228, 1977 Munsat TL: Ethical issues in amyotrophic lateral sclerosis. In The Diagnosis and Treatment of Amyotrophic Lateral Sclerosis Mulder DW (Ed). Boston: Houghton-Mifflin, 1979, pp. 321-323 Worthington K: Making a positive decision about going on a life support system. ALSSOAN 6:5-11, 1981 Goldblatt D (Ed): Solving the Problems of Amyotrophic Lateral Sclerosis: A Guide for Patients. Families, and Health Care Providers. (In press)