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Some nightmares are all too common. A physically fit, 33-year-old man who has never had a serious illness begins to experience leg muscle cramps, muscle twitches and some ankle weakness. He is referred to a neurologist by the family doctor. An electrodiagnostic study, MRI, and some blood tests are done and the neurologist tells him that he has an incurable, untreatable disease called amyotrophic lateral sclerosis (ALS), and has 15 to 18 months to live. The same happens to a 29-year-old pregnant woman. The incidence of ALS is one to two out of 100,000 people per year.
Another common nightmare involves a young couple who has just had their first baby. The child is “floppy”— tending to slip through their hands as they lift him — and is diagnosed with a neuromuscular disease called spinal muscular
atrophy (SMA) type 1. The diagnosing neurologists tell the parents that the child will die before his second birthday because of respiratory complications of
respiratory muscle weakness. They say there is no cure, no effective medical treatment and nothing to be done except to help him die “more easily.”
These two conditions are just the “tip of the iceberg.” The most common childhood neuromuscular disease is Duchenne muscular dystrophy. In general, Duchenne patients die as adolescents or young adults of complications of respiratory muscle weakness. Although some of them live into adulthood, the majority have tracheostomy tubes and receive continuous (invasive) mechanical respiratory support.
At UMDNJ-University Hospital (UH) in Newark, the picture is very different. None of the more than 100 Duchenne patients who have used respiratory muscle aids have died from respiratory complications in more than 10 years and none have required invasive tubes in their necks for 25 years.
While orthopedic surgeons, or “bone doctors,” and neurologists, or “nerve doctors,” have been around for a long time, there were no “muscle doctors” until physical medicine and rehabilitation, also known as physiatry, was formally established as a specialty in 1947. Much of physical medicine research is concerned with muscle function. My group’s research addresses how to alleviate the weakness and dysfunction of the respiratory muscles.
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| Figure 1:
25-year-old man with Duchenne muscular dystrophy, continuously dependent on mechanical ventilation via a mouthpiece during the day and nasal interface during sleep. He is also a singer and composer in the jazz-rock group DMD (Dreams Music Directory). The group issued their second CD in 2003. |
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| Figure 2:
17-year-old male with acute ventilatory failure status post spinal cord injury using noninvasive ventilation continuously via simple mouthpiece during daytime hours and lipseal (seen here) during sleep. This patient was dependent on noninvasive mechanical ventilation for 10 days before weaning and being transferred for acute rehabilitation. |
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| Figure 3:
Brothers, 11 and 8 years of age, with severe spinal muscular atrophy type 1. Both have been dependent on continuous noninvasive mechanical ventilation since five months of age. Each has had only one brief hospitalization since birth. Both are straight "A" students in school despite the fact that they must communicate via computer/voice synthesizer. |
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| Figure 4:
High level spinal cord injured male who has used the intermittent abdominal pressure ventilator for 14 years for daytime ventilatory support and lipseal ventilation during sleep. |
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Neuromuscular diseases cause generalized muscle weakness, leading to morbidity and mortality from weakness of three respiratory muscle groups: the inspiratory (breathing), expiratory (coughing), and bulbar-innervated (throat) muscles. However, the inspiratory and expiratory muscles can be completely dysfunctional (paralyzed) without patients developing respiratory failure or requiring tracheostomy tubes. We have patients who have had absolutely no functioning muscle below the neck and no ability to breathe or cough for more than 55 years who have never required, and will never require, tracheostomy tubes, and who have suffered no respiratory morbidity in decades.
Although we can completely compensate for weakness of inspiratory and expiratory musculature, the same cannot be said for the bulbar-innervated muscles. If they become dysfunctional, and speech and swallowing are lost, and so much saliva is aspirated into the airway that the blood oxygen saturation level decreases below 95% despite adequate use of inspiratory and expiratory muscle aids, then 90% of such patients will have to undergo tracheotomy or will die within two months. Fortunately, this happens infrequently, only affecting those with the “bulbar” type of Lou Gehrig’s disease.
What are (noninvasive) physical medicine respiratory muscle aids?
Inspiratory and expiratory muscle aids are devices and techniques that involve the manual or mechanical application of forces to the body, or intermittent pressure changes to the airway, to assist inspiratory or expiratory muscle function. Negative pressure applied to the airway during expiration or coughing assists the expiratory muscles as forced exsufflation, just as positive pressure applied to the airway during inhalation — noninvasive ventilation — assists the inspiratory muscles.
For example, rather than receiving ventilatory support via invasive tubes in the neck or throat, our patients receive daytime ventilatory support by simply grabbing a small mouthpiece within their reach for big “breaths” (Figure 1). They use the same mouthpiece method, with a plastic phalange to provide security, during sleep (Figure 2), or simply use nasal ventilation overnight (Figure 3). Some patients use the intermittent abdominal pressure ventilator, a girdle with an air bladder inside it that is filled and passively emptied of air, causing air to enter the lungs via the upper airway (Figure 4).
Intermittent lung hyperinflation is prescribed to maintain lung elasticity, prevent atelectasis (lung collapse) and permit the patient to raise voice volume, shout and cough. Hyperinflation is achieved by learning to “air stack” consecutively delivered ventilator volumes and holding them with a closed glottis until the lungs are maximally inflated. Just as for weak skeletal muscles that stiffen into musculotendinous contractures if not aggressively mobilized on a regular basis, the lungs and chest walls of patients with weak respiratory muscles require comparable therapy by regular lung expansion beyond vital capacity.
Coughing is the principal mechanism for clearing the central six divisions of the respiratory tree. Without an effective cough, no one can use noninvasive ventilation for very long. Intercurrent chest infections invariably result in pneumonia and respiratory failure if the patient is not strong enough to cough out airway secretions or is not taught how to use expiratory muscle aids to do so. The importance of manually assisted coughing to permit effective long term use of noninvasive ventilation cannot be overstated. We demonstrated that cough peak flows (CPF) are greatly increased by it. The most important part of a manually assisted cough is air stacking to a maximal lung insufflation.
The doctor's dilemma
When I was a resident in physical medicine and rehabilitation in the late 1970s, I saw patients with very weak respiratory muscles using a strange-looking device called a “Cof-flator.” The patients swore that the device saved them from developing pneumonia and respiratory failure during intercurrent respiratory tract infections. The Cof-flator was briefly on the market in the early ’50s, and the few that were still in circulation some 20 years later were being shared by patients who needed them during chest infections. For 20 years patients begged for these devices to be put back on the market. I asked all the ventilator manufacturers to consider manufacturing this device. In the late ’80s, Jack Emerson, the former manufacturer of iron lungs and negative pressure body ventilators, accommodated me. With support from an Innovation Grant from the State of New Jersey Department of Education Rehabilitation Research Division, we did studies on in-exsufflation that led to the February 1993 FDA approval of the “In-exsufflator” (today called “CoughAssistTM).
These devices deliver deep insufflations followed immediately by deep exsufflations, thus assisting inspiratory, then expiratory, muscles for effective cough flows exceeding 10 L/sec. Insufflation to exsufflation pressures of +40 to -40 cm H2O delivered via oronasal interface, or even tracheostomy tubes when present, are effective and preferred by most patients. Lungs are insufflated until fully expanded and then immediately exsufflated until they are fully emptied and the chest wall retracted. The availability of this device has resulted in the sparing of hundreds of lives and the avoidance of hundreds of hospitalizations for people with ALS, spinal muscular atrophy, and all of the muscular dystrophies. In addition to use for assisted coughing, the device can also provide full chest expansion for people whose oral muscles are too weak for effective air stacking.
The use of this device has permitted us to consistently extubate patients following general anesthesia despite their lack of any independent breathing ability, and to manage them with noninvasive IPPV. Patients who are considered poor surgical candidates elsewhere because of their inability to take a deep breath (vital capacity less than 40% of normal), or even any ability to breathe at all, can undergo general anesthesia and be managed post-operatively without any consideration of resorting to tracheotomy because of pre-operative training in and post-operative use of these noninvasive respiratory aids.
Patients come to UH from all over the country to be managed noninvasively and to have tracheostomy tubes removed when they would not be removed elsewhere. Quality of life and ventilator weaning are greatly enhanced by elimination of tracheostomy tubes in favor of noninvasive inspiratory and expiratory muscle aids. All patients with experience in using both invasive and noninvasive methods, who are converted to the latter, prefer this to tracheostomy for safety, appearance, speech and swallowing and feel it is more satisfactory overall. Avoidance of invasive ventilatory support also facilitates home management rather than institutionalization and greatly decreases costs.
Glossopharyngeal breathing (GPB) is a noninvasive method for providing deep lung insufflations and continuous noninvasive ventilatory support by using one’s own throat muscles instead of a respirator. Both inspiratory and, indirectly, expiratory muscle function are assisted by GPB. This method can provide an individual with incapacitated inspiratory muscles and no breathing ability with normal lung ventilation and perfect safety in the event of ventilator failure day or night. The technique involves the use of the glottis to add to an inspiratory effort by projecting (gulping) boluses of air into the lungs. The glottis closes with each “gulp.” One breath usually consists of six to nine gulps of 40 to 200 ml each.
Despite the obvious benefits of using these noninvasive methods over invasive tracheostomy, only a handful of the more than 400 neuromuscular disease clinics in the U.S. offer them to their patients with Lou Gehrig’s disease, muscular dystrophy, myasthenia gravis, spinal muscular atrophy and similar conditions. Our success, however, has led to the development of the Center for Noninvasive Mechanical Ventilation and Pulmonary Rehabilitation at University Hospital. The center has physicians, as well as surgeons, who provide surgical interventions under local anesthesia that are done nowhere else. Center physicians are expert at extubating unweanable patients to noninvasive aids rather than tracheostomy ventilation. The pediatric intensive care unit at UH has a 90% success rate at extubating infants and small children in ventilatory failure with SMA1, whereas the conventional success rate is literally 6% elsewhere. The success of our physicians in training and equipping patients and their relatives to provide these aids has become a magnet for physicians, nurses, and therapists from all over the world to come for training. Seventy such healthcare professionals from Europe, Asia, and North and South America have been trained by us over the last two years. Center physicians have lectured on these methods in more than 40 countries around the world and have produced 10 books and more than 300 articles and book chapters on these methods.
John R. Bach, MD, is a professor of physical medicine and rehabilitation and
neurosciences at UMDNJ-New Jersey Medical School. He is also vice chair of the Department of Physical Medicine and Rehabilitation and co-director of the Muscular Dystrophy Association Clinic at UMDNJ-University Hospital (UH). Dr. Bach is medical director of the Center for Noninvasive Mechanical Ventilation Alternatives and Pulmonary Rehabilitation at UH. He has authored more than 250 peer reviewed scientific articles and book chapters and 10 medical textbooks
on neuromuscular and pulmonary medicine and has lectured on these topics in 40 countries around the globe. He has received many awards for excellence in research writing and patient care.
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