Intermittent abdominal pressure ventilator in a regimen of noninvasive ventilatory support

Is Intermittent Abdominal Pressure Ventilation Still Relevant? A Multicenter Retrospective Pilot Study

Non-invasive ventilatory support (NVS) is a technique used to reduce respiratory work in neuromuscular diseases, preventing the progression of respiratory failure. NVS is usually administered via a nasal or an oronasal mask, causing discomfort, especially in patients ventilated for more than 16 h/day. Intermittent abdominal pressure ventilation (IAPV) differs completely from conventional NVS and consists of a portable ventilator and a corset with Velcro closures as the interface. In our study, the practicability and efficacy of IAPV were studied in three Italian centers monitoring 28 neuromuscular patients using IAPV who were then retrospectively analyzed. The primary outcomes were an improvement in hypoxemia and the normalization of hypercapnia, and the secondary outcome was an improvement in quality of life. Data were collected at baseline (T0) and after two hours of ventilation (T1), with follow-ups at three months (T2) and six months (T3). Statistical significance was found for PaCO₂ over time (F (2.42) = 7.63, p = 0.001) and PaO₂ (W = 0.539, p = 0.033). The time of NVS usage also significantly affected the quality of life (F (2.14) = 6.90, p = 0.010), as seen when comparing T0 and T3. As an alternative ventilation method, IAPV is still relevant today and could become a key part of daytime support, especially for patients who do not tolerate standard daytime NVS with an oral interface.

Intermittent abdominal pressure ventilation management in neuromuscular diseases: a Delphi panel Consensus

BACKGROUND

Intermittent abdominal pressure ventilator (IAPV) use started in the 1930s for ventilatory assistance with muscular dystrophy patients. Later, the device was perfected and expanded for other neuromuscular disorders (NMD). In recent years, the morbidity and mortality tracheotomies and trach tubes related renewed the interest around IAPV. However, there are no guidelines for its use. This study aimed to establish a consensus among physicians involved in its practice to provide IAPV suggestions for the treatment of patients with NMD.

METHOD

A 3-step modified Delphi method was used to establish consensus. Fourteen respiratory physicians and one psychiatrist with strong experience in IAPV use and/or who published manuscripts on the topic participated in the panel. A systematic review of the literature was carried out according to the PRISMA to identify existing evidence on IAPV for patients with neuromuscular disorders.

RESULTS

In the first round, 34 statements were circulated. Panel members marked 'agree' or 'disagree' for each statement and provided comments. The agreement was reached after the second voting session for all 34 statements.

CONCLUSIONS

Panel members agreed and IAPV indications, parameter settings (including procedure protocol), potential limitations, contraindications, complications, monitoring, and follow-up are described. This is the first expert consensus on IAPV.

The Intermittent Abdominal Pressure Ventilator as an Alternative Modality of Noninvasive Ventilatory Support: A Narrative Review

ABSTRACT

Noninvasive ventilation has become the initial treatment for symptomatic ventilatory pump failure but, when used at ventilatory support settings, can be an alternative to tracheostomy mechanical ventilation. The intermittent abdominal pressure ventilator, a corset with an internal air sack inflated by a ventilator, allows to increase tidal volumes through the raising of the diaphragm and its consequent passive descent. It has been used for daytime support for more than 70 yrs, but its knowledge among clinicians is scarce. A narrative review was performed by searching PubMed, Medline, and the Cochrane Database of Systematic Reviews using the terms "IAPV" or "pneumobelt." One hundred forty patients were cited using the intermittent abdominal pressure ventilator from 1946 until it went off the market in the 1970s, although many continued to use it. There was only one publication on its use from 2003 to 2017, but three publications from 2017 through 2021. It has been used for full diurnal ventilatory support by some patients for more than 50 yrs and has even been used throughout the labor of a mother with no ventilator-free breathing ability. The intermittent abdominal pressure ventilator is a ventilatory support alternative for patients with ventilatory pump failure. It can be effective and well tolerated and maintain quality of life without facial interfaces. More widespread application is warranted.

Intermittent Abdominal Pressure Ventilation: An Alternative for Respiratory Support

Intermittent abdominal pressure ventilation is a positive pressure ventilation technique that works with abdominal compressions. It has been known since 1938; however, for many years, it was out of production. In recent years, a new device has been produced that has captured the attention to this old respiratory support technique. We considered eight patients with respiratory failure secondary to a neuromuscular disease (congenital myopathy, Duchenne dystrophy, and amyotrophic lateral sclerosis) intolerant to daytime noninvasive ventilation (NIV). IAPV was proposed as an alternative to NIV. We performed baseline and post-IAPV respiratory function assessment. All patients, two years later, are still using intermittent abdominal ventilation. Intermittent positive abdominal mechanical ventilation can be a valid alternative to noninvasive mechanical ventilation with a nasal or face mask. It improves gas exchange, symptoms, and quality of life, decreases the incidence of pneumonia, and can avert the need for intubation and tracheotomy.

Intermittent abdominal pressure ventilation: feasibility and efficacy in neuromuscular disease. A case report

he standard treatment for patients with neuromuscular respiratory failure is non-invasive ventilation (NIV) as non-invasive ventilation support-setting (NVS). NVS is administered through a nasal or face mask and/or mouthpiece with the potential to cause nasal ulcers, discomfort, and/or aesthetic issues, resulting in poor compliance. We reported the observation of a 45-year-old woman with limb-girdle muscular dystrophy (LGMD), secondary to Dysferlin deficiency, who was on NVS since 2017 for nocturnal hypoventilation. In 2018, despite nocturnal ventilation, due to weight gain and daytime hypoventilation, a nasal mask was introduced. We initiated daytime intermittent abdominal pressure ventilation (IAPV) to mitigate cosmetic problems, improving in pO2 and decreasing in pCO2 versus baseline (52>84 mmHg, 46>33 mmHg respectively) at 6 (85 mmHg, 42 mmHg) and 18 months (93 mmHg, 38 mmHg), respectively. IAPV was effective, safe, and well-tolerated in our patients who did not tolerate standard daytime NVS with the known interface.

Daytime alternatives for non-invasive mechanical ventilation in neuromuscular disorders

Mechanical ventilation in recent years has benefited from the development of new techniques and interfaces. These developments allowed clinicians to offer increasingly personalised therapies with the combination of different complementary techniques for treating respiratory insufficiency in patients with neuromuscular diseases. The mouthpiece ventilation, intermittent abdominal pressure ventilator and the negative pressure ventilation can offer many patients alternative therapy options when ventilation is required for many hours a day. In this non-systematic review, we will highlight the use of alternative methods to non-invasive mechanical ventilation at positive pressure in neuromuscular patients, to ensure the optimal interface for each patient.

Noninvasive Respiratory Management of Spinal Cord Injury

Intubated ventilator-dependent patients with high-level spinal cord injury can be managed without tracheostomy tubes provided that they have sufficient cognition to cooperate and that any required surgical procedures are completed and they are medically stable. Intubation for a month or more than extubation to continuous noninvasive ventilatory support (NVS) can be safer long term than resort to tracheotomy. Noninvasive ventilation (NIV) is not conventionally being used for ventilatory support. Noninvasive interfaces include mouthpieces, nasal and oronasal interfaces, and intermittent abdominal pressure ventilators. NIV/NVS should never been used without consideration of mechanical insufflation-exsufflation for airway secretion clearance.

Daytime noninvasive ventilatory support for patients with ventilatory pump failure: a narrative review

Over the past three decades, the use of noninvasive ventilation or "NIV" to assuage symptoms of hypoventilation for patients with early onset or mild ventilatory pump failure has been extended to up to the use of continuous noninvasive ventilatory support (CNVS) at full ventilatory support settings as a definitive alternative to tracheostomy mechanical ventilation. NVS, along with mechanical insufflation-exsufflation, now provides a noninvasive option for the management of both chronic and acute respiratory failure for these patients. The most common diagnoses for which these methods are useful include chest wall deformities, neuromuscular diseases, morbid obesity, high level spinal cord injury and idiopathic, primary or secondary disorders of the ventilatory control. Thus, NVS is being used in diverse settings: critical care units, medical wards, at home, and in extended care. The aim of this review is to examine the techniques used for daytime support.

Abdominal Displacement Ventilation: An Effective Intervention for Sedation-Induced Hypoxia

Background

Sedation for bronchoscopy at times causes hypoxia. The application of positive pressure ventilation for sedation-induced hypoxia often requires cessation of the bronchoscopy. In contrast, ventilation effected via cyclical abdominal compression, if effective, would allow bronchoscopy to proceed. Initial trials of abdominal displacement ventilation (ADV) proved successful. This report documents extended experience with ADV.

Objective

To evaluate and report the efficacy and applicability of ADV in the setting of sedation-induced hypoxia for consecutive patients over an extended interval.

Methods

Based upon its initial efficacy, ADV had been incorporated into the standard approach to sedation-induced hypoxia. We retrospectively reviewed all bronchoscopies performed by interventional pulmonary over a 12-month interval. Management and efficacy of every episode of sedation-induced hypoxia were documented.

Results

Over the study interval, 893 bronchoscopies had been performed, with sedation-induced hypoxia occurring in 38 (4%). ADV was possible in 37 of the 38 patients. In every case, ADV was effective and allowed completion of the procedure. There were no adverse effects.

Conclusion

ADV is a simple, effective, noninvasive approach to sedation-induced hypoxia that effects adequate ventilation and allows safe continuance of procedures.

NIV in amyotrophic lateral sclerosis: The 'when' and 'how' of the matter

Non-invasive ventilation (NIV) has become an essential part of the treatment of amyotrophic lateral sclerosis (ALS) since 2006. NIV very significantly improves survival, quality of life and cognitive performances. The initial NIV settings are simple, but progression of the disease, ventilator dependence and upper airway involvement sometimes make long-term adjustment of NIV more difficult, with a major impact on survival. Unique data concerning the long-term adjustment of NIV in ALS show that correction of leaks, management of obstructive apnoea and adaptation to the patient's degree of ventilator dependence improve the prognosis. Non-ventilatory factors also impact the efficacy of NIV and various solutions have been described and must be applied, including cough assist techniques, control of excess salivation and renutrition. NIV in ALS has been considerably improved as a result of application of all of these measures, avoiding the need for tracheostomy in the very great majority of cases. More advanced use of NIV also requires pulmonologists to master the associated end-of-life palliative care, as well as the modalities of discontinuing ventilation when it becomes unreasonable.

Efficacy of new intermittent abdominal pressure ventilator for post-ischemic cervical myelopathy ventilatory insufficiency

Non-invasive ventilation (NIV) is the treatment of choice for patients symptomatic for respiratory muscle dysfunction. It can normalize gas exchange and provide up to continuous non-invasive ventilator support (CNVS) as an alternative to intubation and tracheotomy. It is usually provided via non-invasive facial interfaces or mouthpieces, but these can be uncomfortable and uncosmetic. The intermittent abdominal pressure ventilator (IAPV) has been used for diurnal ventilatory support since 1938 but has been off the market since about 1990. Now, however, with greater emphasis on non-invasive management, a new IAPV is available. A patient with chronic ventilatory insufficiency post-ischemic cervical myelopathy, dependent on sleep NVS since 2003, developed symptomatic daytime hypercapnia for which he also used diurnal NVS via nasal pillows. However, he preferred not having to use facial interfaces. When not using diurnal NVS he was becoming dyspnoeic. Diurnal use of an IAPV was introduced. Arterial blood gas analysis using the IAPV decreased his blood pH from 7.45 to 7.42, PaCO₂ from 58 to 37 mmHg, and improved PaO₂ from 62 to 92 mmHg. At discharge, the patient used the IAPV 8 h/day with improved mood and quality of life. Consequently, he returned to work as a painter.

Noninvasive Respiratory Management of Patients With Neuromuscular Disease

This review article describes definitive noninvasive respiratory management of respiratory muscle dysfunction to eliminate need to resort to tracheotomy. In 2010 clinicians from 22 centers in 18 countries reported 1,623 spinal muscular atrophy type 1 (SMA1), Duchenne muscular dystrophy (DMD), and amyotrophic lateral sclerosis users of noninvasive ventilatory support (NVS) of whom 760 required it continuously (CNVS). The CNVS sustained their lives by over 3,000 patient-years without resort to indwelling tracheostomy tubes. These centers have now extubated at least 74 consecutive ventilator unweanable patients with DMD, over 95% of CNVS-dependent patients with SMA1, and hundreds of others with advanced neuromuscular disorders (NMDs) without resort to tracheotomy. Two centers reported a 99% success rate at extubating 258 ventilator unweanable patients without resort to tracheotomy. Patients with myopathic or lower motor neuron disorders can be managed noninvasively by up to CNVS, indefinitely, despite having little or no measurable vital capacity, with the use of physical medicine respiratory muscle aids. Ventilator-dependent patients can be decannulated of their tracheostomy tubes.

Management of pulmonary complications in neuromuscular disease

Restrictive lung disease occurs commonly in patients with neuromuscular disease. The earliest sign of respiratory compromise in the patient with neuromuscular disease is nocturnal hypoventilation, which progresses over time to include daytime hypoventilation and eventually the need for full-time mechanical ventilation. Pulmonary function testing should be done during regular follow-up visits to identify the need for assistive respiratory equipment and initiate early noninvasive ventilation. Initiation of noninvasive ventilation can improve quality of life and prolong survival in patients with neuromuscular disease.

Mucus clearance from the pulmonary system by mechanical means: a dual-excitation approach

A dual-excitation approach to mechanical clearance of mucus from the pulmonary system is described. The approach employs independently controlled vibratory and constrictive pressure stimulations to the thorax. Patient cooperative efforts are integrated into the therapy regimen as a means of enhancing the efficacy of the treatment. An engineering model that demonstrates the capability to generate vibratory and constrictive pressure variations at specified levels is described.

Noninvasive respiratory management and diaphragm and electrophrenic pacing in neuromuscular disease and spinal cord injury

The purpose of this monograph is to describe noninvasive management of respiratory muscle weakness/paralysis for patients with neuromuscular disease (NMD) and spinal cord injury (SCI). Noninvasive ventilation (NIV) assists and supports inspiratory muscles, whereas mechanically assisted coughing (MAC) simulates an effective cough. Long-term outcomes will be reviewed as well as the use of NIV, MAC, and electrophrenic pacing (EPP) and diaphragm pacing (DP) to facilitate extubation and decannulation. Although EPP and DP can facilitate decannulation and maintain alveolar ventilation for high-level SCI patients when they cannot use NIV because of lack of access to oral interfaces, there is no evidence that they have any place in the management of NMD.

Electrophrenic pacing and decannulation for high-level spinal cord injury: a case series

BACKGROUND

In 1997, guidelines were developed for the management of high-level ventilator-dependent patients with spinal cord injury who had little or no ventilator-free breathing ability (VFBA). This article describes the three categories of patients, the decannulation criteria, and the successful decannulation of four patients with no VFBA and electrophrenic/diaphragm pacing, using these criteria.

METHOD

Case series.

CONCLUSION

Lack of VFBA in patients with high-level spinal cord injury does not mandate tracheostomy or electrophrenic/diaphragm pacing.

Noninvasive respiratory management of high level spinal cord injury

This article describes noninvasive acute and long-term management of the respiratory muscle paralysis of high spinal cord injury (SCI). This includes full-setting, continuous ventilatory support by noninvasive intermittent positive pressure ventilation (NIV) to support inspiratory muscles and mechanically assisted coughing (MAC) to support inspiratory and expiratory muscles. The NIV and MAC can also be used to extubate or decannulate 'unweanable' patients with SCI, to prevent intercurrent respiratory tract infections from developing into pneumonia and acute respiratory failure (ARF), and to eliminate tracheostomy and resort to costly electrophrenic/diaphragm pacing (EPP/DP) for most ventilator users, while permitting glossopharyngeal breathing (GPB) for security in the event of ventilator failure.

Oximetry and indications for tracheotomy for amyotrophic lateral sclerosis

STUDY OBJECTIVE

To explore the use of oximetry as a guide for using respiratory aids and tracheotomy in the treatment of patients with amyotrophic lateral sclerosis (ALS).

SETTING

A retrospective review of all ALS patients presenting to a neuromuscular disease clinic since 1996.

METHODS

Patients who were symptomatic for nocturnal hypoventilation were prescribed noninvasive ventilation (NIV). Patients with assisted cough peak flows of < 300 L/min were prescribed oximeters and access to mechanically assisted coughing (MAC) to prevent or reverse decreases in baseline pulse oximetric saturation (Spo(2)) levels of < 95%. The number of decreases in baseline Spo(2) that could be normalized by any combination of NIV and MAC and the duration of normalization were recorded. When the baseline was not or could not be normalized, the time to acute respiratory failure and tracheotomy or death were recorded.

RESULTS

Twenty-five patients became dependent on NIV, including 13 patients who received NIV continuously for a mean (+/- SD) period of 19.7 +/- 16.9 months, without desaturation (group 1). For another 76 patients, the daytime baseline Spo(2) level decreased to < 95% 78 times. For 41 patients, the baseline level was corrected by NIV/MAC (group 2) for a mean duration of 11.1 +/- 8.7 months before desaturation reoccurred for 27 patients. Of the latter patients, 11 underwent tracheotomy, 14 died in < 2 months, and 2 had their condition again corrected by the addition of MAC therapy. For 35 patients, the desaturation was not or could not be normalized (group 3). Thirty-three of these 35 patients required tracheotomy or died within 2 months. The only significant difference between groups 1 and 2 and group 3 was significantly poorer glottic function in the patients in group 3.

CONCLUSION

Tracheotomy or death is highly likely within 2 months of a decrease in baseline Spo(2) that cannot be corrected by NIV or MAC. The long-term use of NIV and MAC, and the avoidance of tracheotomy is dependent on glottic function rather than on inspiratory or expiratory muscle failure.

Spinal muscular atrophy

Spinal muscular atrophy is a common genetic disease of the motor neuron (frequency of eight cases per 100,000 live births) with a high mortality during infancy and no known treatment. Death is caused by severe and progressive restrictive lung disease. New information regarding the nature and function of the SMN protein and the availability of new pharmacologic agents now make it possible to consider clinical trials in this disease. Rehabilitation and proper management of medical complications have improved both the quality and duration of life for children with spinal muscular atrophy.

A novel form of manually assisted ventilation

We report an individual with limb-girdle muscular dystrophy who has devised a way to assist her respiration by using her hands braced against the tray of her wheelchair. Utilizing this method, she was able to increase her tidal volume (VT) and lower her respiratory rate compared to unassisted spontaneous breathing, thereby maintaining a stable minute volume. The manually assisted VT measurements were comparable to those achieved using an intermittent abdominal pressure respirator (pneumatic belt). We believe that others with neuromuscular syndromes could use this technique, possibly decreasing their dependence on mechanical ventilatory assist devices.

Pulmonary physical medicine interventions for elderly patients with muscular dysfunction

The respiratory consequences of respiratory muscle impairment, with or without bulbar muscle weakness, usually involve inadequate ventilation and airway secretion encumbrance and may progress to respiratory failure. This article focuses on muscular dysfunction of the bulbar and respiratory musculature in elderly patients with neuromuscular diseases or central nervous system disorders. In addition, the article discusses application of pulmonary physical medicine principles for patients with predominantly restrictive pulmonary disorders caused primarily by muscular dysfunction. Diagnostic evaluation, respective clinical courses and responses to therapy, and the use of noninvasive ventilatory support outside of an acute care setting are also reviewed.

Diaphragm kinetics during pneumatic belt respiratory assistance: a sonographic study in Duchenne muscular dystrophy

The principal aim of this study was to demonstrate the usefulness of M-mode sonography as a noninvasive technique to evaluate diaphragm excursion. The secondary aim was to assess the efficacy of pneumatic abdomino-diaphragmatic belt ventilation in patients with Duchenne muscular dystrophy. Using M-mode sonography, we measured the amplitude of diaphragm excursion in seven patients with Duchenne muscular dystrophy in various positions (0 degrees, 45 degrees, 75 degrees ) with and without pneumatic abdomino-diaphragmatic belt respiratory assistance. The belt significantly increased mean amplitude of diaphragm excursion by 62% at 45 degrees and by 55% at 75 degrees, and increased mean tidal volume by 43.5% at 45 degrees and by 49% at 75 degrees. Two patients were unable to tolerate the horizontal position (0 degrees ) During quiet breathing without the belt, amplitude of diaphragm excursion and tidal volume were positively correlated at 45 degrees (r=0.81; P=0.027) and 75 degrees (r=0.75; P=0.05). There was a significant intra-individual correlation between these two parameters during belt use but no inter-individual correlation. Without the belt, thoracic posture had no significant effect on amplitude of diaphragm excursion, either in quiet or deep breathing. After overnight respiratory assistance, arterial oxygen pressure and arterial oxygen saturation increased significantly, and arterial carbon dioxide pressure decreased from 52+/-6.4 to 46.4+/-4 mmHg. The pneumatic abdomino-diaphragmatic belt significantly improved gas exchanges and ventilation by increasing diaphragm excursion, as was clearly shown by noninvasive M-mode sonography. Indeed, M-mode sonography may be helpful in pneumatic abdomino-diaphragmatic belt pressure adjustment.

Amyotrophic lateral sclerosis: prolongation of life by noninvasive respiratory AIDS

STUDY OBJECTIVE

To describe prolongation of survival in patients with amyotrophic lateral sclerosis (ALS) by continuous noninvasive intermittent positive-pressure ventilation (NPPV) and mechanically assisted coughing (MAC) using oximetry as feedback.

SETTING

A retrospective review of ALS patients visiting one center from 1990 to 2000.

DESIGN

Patients were trained in mouthpiece and nasal NPPV when symptomatic for hypoventilation, and trained in MAC with oximetry feedback when assisted peak cough flow (PCF) levels decreased to < 270 L/min. Survival was considered to be prolonged when full-time NPPV was required with limited ventilator-free breathing tolerance.

RESULTS

Of 101 patients who met the criteria for access to NPPV and MAC, 15 have not yet used them, and 11 patients with severe bulbar muscle dysfunction died without ever successfully using them. Three patients used NPPV full-time, and oximetry and MAC episodically, but did not yet require ongoing NPPV. Eighteen used NPPV part-time for a mean (+/- SD) duration of 3.8 +/- 4.1 months. Nineteen others underwent tracheotomy after 4.7 +/- 4.5 months of receiving part-time NPPV. Sixteen patients used part-time NPPV for 17.5 +/- 13.0 months (maximum, 25 months), then full-time NPPV for 14.1 +/- 12.6 months (maximum, 40 months) before undergoing tracheotomy. Nineteen patients used part-time and full-time NPPV for 25.2 +/- 19.8 months (maximum, 114 months) and 17.5 +/- 13.3 months (maximum, 87 months), respectively, without undergoing tracheotomy. Ten of these NPPV users died once bulbar dysfunction became severe.

CONCLUSION

We conclude that up to continuous use of NPPV, along with MAC when needed, can permit prolonged survival and delay the need for tracheotomy for a significant minority of ALS patients by > 1 year.

Evaluation and rehabilitation of patients with adult motor neuron disease

Adult motor neuron disease (amyotrophic lateral sclerosis [ALS]) is a neurodegenerative disorder characterized by loss of motor neurons in the cortex, brain stem, and spinal cord, manifested by upper and lower motor neuron signs and symptoms affecting bulbar, limb, and respiratory musculature. Clinically, the disease course is characterized by progressive weakness, atrophy, spasticity, dysarthria, dysphagia, and respiratory compromise, ultimately resulting in death or mechanical ventilation in the vast majority of patients. Patterns of presentation and pathological features of the disease, along with clinical and electrophysiologic criteria for diagnosis, are discussed in this review. Since 8% to 22% of patients survive more than 10 years without ventilator use, meticulous medical and rehabilitation management is extremely important to ensure optimal health and quality of life in these patients. Major issues in the care of individuals with ALS include weakness and spasticity, impairments in activities of daily living and mobility, communication deficits and dysphagia in those with bulbar involvement, respiratory compromise, fatigue and sleep disorders, pain, and psychosocial distress. Research in ALS changes rapidly, but is currently focused on potential etiologic factors such as glutamate excitotoxicity, role of oxidative stress, autoimmunity to calcium channels, and cytoskeletal abnormalities, as well as related treatment initiatives including glutamate modulators, neurotrophic factors, antioxidants, antiapoptotic factors, and gene therapy. Recently, mutations in the gene encoding Cu/Zn superoxide dismutase were identified in a subset of familial ALS patients. Riluzole, a glutamate antagonist and Na-channel blocker, became the only drug currently approved for treatment of ALS after studies showed a small positive effect on survival. Until a definitive treatment or cure for ALS is found, the multifaceted rehabilitation team approach remains the best hope for improving health and survival in this devastating illness.

Noninvasive ventilation in neuromuscular disease

The treatment of respiratory failure in patients who have NMD continues to be an evolving process. Negative-pressure ventilation, once prominent in the 1940s and 1950s, gave way to intermittent positive-pressure ventilation with tracheostomy or endotracheal tubes in the 1960s. Now there is a resurgence of noninvasive ventilation, brought about by innovative modes of positive pressure delivered through nasal and facial masks. Although frequently relegated to second-line choices, negative-pressure devices still offer a practical treatment alternative as patient preference still plays a role in selecting a proper mode of ventilation. Studies have shown that noninvasive ventilation can prevent or reverse respiratory failure and improve quality of life and longevity. Despite the seemingly widespread acceptance of noninvasive ventilation in the treatment of respiratory failure, physicians still appear reluctant to use ventilatory assistance in the neuromuscular arena. In 1985, a survey found that respiratory support systems were utilized routinely in only 33% of the 132 responding Muscular Dystrophy Association (MDA) clinics. Bach recently surveyed 273 MDA clinic directors and co-directors from 167 clinics, to evaluate their current use of mechanical ventilation. Ventilatory assistance was recommended and used electively in only 43 (26%) of the 167 clinics. Furthermore, it was the policy in 68 of the clinics to discourage the use of mechanical ventilation. Even more importantly, only 2 physicians who discouraged the use of mechanical ventilation were familiar with the newest noninvasive methods of ventilatory support. Sadly, although our methodologies in the treatment of respiratory failure continue to improve, physician practice has lagged behind. Physicians who treat patients who have NMD need to become cognizant of these new techniques and incorporate them into their present therapeutic armamentarium.

The management of neuromuscular ventilatory failure

All patients with respiratory impairment have either primarily ventilatory or primarily oxygenation impairment. Patients with neuromuscular conditions fall into the former category but are all too often managed as though they had the latter with oxygen therapy, bronchodilators, chest physical therapy, intermittent positive pressure breathing, and so on. This approach can only hasten respiratory failure and management by tracheostomy-However, it has been reported that with the use of noninvasive respiratory muscle aids, respiratory morbidity and mortality can be prevented for most patients with neuromuscular disease without resort to tracheostomy or even hospitalization.

Cardiovascular, pulmonary, and cancer rehabilitation. 2. Pulmonary rehabilitation

This self-directed learning module highlights both pulmonary and nonpulmonary aspects in the rehabilitation of patients with pulmonary disease and the assessment and physical therapeutic options in the pulmonary management of patients with neurological disorders. It is part of the chapter on cardiovascular, pulmonary, and cancer rehabilitation in the Self-Directed Physiatric Education Program for practitioners and trainees in physical medicine and rehabilitation. New advances covered in this section include the use of physical medicine modalities for respiratory muscle rest and technological advances in the management of airway secretions in both pulmonary and neurological disorders. For the former, these approaches can decrease symptoms and the frequency of hospitalization and increase exercise tolerance and quality of life. The use of physical medicine modalities will be discussed as inspiratory and expiratory muscle aids. These methods, when used as alternatives to tracheal intubation and long-term tracheostomy in patients with neurological disorders, improve quality of life, minimize cost, enhance survival, and facilitate community care.

Amyotrophic lateral sclerosis: predictors for prolongation of life by noninvasive respiratory aids

The purpose of this study was to determine which pulmonary function variables best predicted the potential for prolonging survival of individuals with amyotrophic lateral sclerosis (ALS) by the use of physical medicine respiratory muscle aid alternatives to tracheostomy for ventilatory support and airway suctioning. The records of 27 such ALS ventilator users with less than 15 minutes of ventilator-free breathing time for a mean +/- standard deviation of 23.7 +/- 20.3 months (range, 1 to 65) were reviewed. All patients underwent measurements of vital capacity (VC), maximum insufflation capacity (MIC), MIC VC difference, forced expiratory volumes, and peak cough expiratory flows (PCEF) every 1 to 6 months, depending on rate of disease progression, until requiring 24-hour ventilatory support. The ability to generate assisted PCEF in excess of 3L/sec and the ability to hold an insufflation deeper than the VC were associated with the capacity to prolong survival by methods other than tracheostomy, whereas the extent of decrease in VC and autonomous breathing ability were not. Because the PCEF and MIC VC difference correlate with bulbar muscle function, it can be concluded that the ability to use 24-hour ventilatory support by noninvasive means is a function of residual bulbar muscle strength and is independent of VC or the extent of need for ventilatory support. Properly equipped and trained, some ALS patients can use noninvasive respiratory muscle aids to delay or eliminate the need for tracheostomy.

Noninvasive long-term ventilatory support for individuals with spinal muscular atrophy and functional bulbar musculature

Ten individuals with spinal muscular atrophy (SMA) and chronic ventilatory insufficiency were trained in the use of assisted coughing techniques and received intermittent positive pressure ventilation (IPPV) via oral and/or nasal interfaces for a mean of 5.3 (range = 1 to 17) years. During this time they had significantly fewer respiratory complications than before introduction of noninvasive respiratory muscle aids despite the fact that 6 of the 10 went on to require more than 20 hours per day of ventilator use with less than 2 hours of ventilator-free breathing time (VFBT). All except two noninvasive IPPV users had vital capacities (VCs) less than 13% of predicted normal. They could, however, communicate verbally and take nutrition by mouth. All of the patients remained in the community. Five patients were gainfully employed and four were in school. We conclude that noninvasive respiratory muscle aids including noninvasive IPPV and assisted coughing techniques are effective and practical alternatives to tracheostomy for SMA patients with ventilatory failure but functional bulbar musculature.