Home negative pressure ventilation: report of 20 years of experience in patients with neuromuscular disease

Development of Home Mechanical Ventilation in Poland in 2009–2019 Based on the Data of the National Health Fund

Home mechanical ventilation (HMV) is a dynamically developing field of medicine driven by the increasing number of patients and technological advancements. In Poland, HMV has been financed from public funds since 2004. However, the organization of HMV is still evolving in search of the optimal model of care. The aim of this study was to analyze 11 years of HMV in terms of the number of patients, modes of ventilation, diagnosis and regional prevalence. In retrospective analysis of data reported to the National Health Fund by all health entities providing HMV in Poland in the period from 2009 to 2019, the following variables were included: age, sex, date of commencement, ventilation mode, diagnosis, and place of treatment. The diseases were identified according to the ICD-10 codes. A total of 12,616 patients receiving HMV were reported, including 1221 children (9.7%). The HMV prevalence increased from 2.8 in 2009 to 20/100,000 in 2019. In adults, the highest increase was reported for patients with chronic obstructive pulmonary disease, who accounted for 39% of all HMV users in 2019. The proportion of noninvasive ventilation (NIV) increased from 56% in 2014 to 73% in 2019. We identified significant regional variations in the prevalence of HMV between provinces. The main drivers for HMV development include full reimbursement, the development of hospital NIV centers and the involvement of respiratory physicians in the referral process for HMV.

A new mode of mechanical ventilation: positive + negative synchronized ventilation

Supporting patients suffering from severe respiratory diseases with mechanical ventilation, obstacles are often encountered due to pulmonary and/or thoracic alterations, reductions in the ventilable lung parenchyma, increases in airway resistance, alterations in thoraco-pulmonary compliance, advanced age of the subjects. All this involves difficulties in finding the right ventilation parameters and an adequate driving pressure to guarantee sufficient ventilation. Therefrom, new mechanical ventilation techniques were sought that could help overcome the aforementioned obstacles. A new mode of mechanical ventilation is being presented, i.e., a Positive + Negative Synchronized Ventilation (PNSV), characterized by the association and integration of two pulmonary ventilators; one acting inside the chest with positive pressures and one externally with negative pressure. The peculiarity of this combination is the complete synchronization, which takes place with specific electronic modifications. The PNSV can be applied both in a completely non-invasive and invasive way and, therefore, be used both in acute care wards and in ICU. The most relevant effect found, due to the compensation of opposing pressures acting on the chest, is that, during the entire inspiratory act created by the ventilators, the pressure at the alveolar level is equal to zero even if adding together the two ventilators' pressures; thus, the transpulmonary pressure is doubled. The application of this pressure for 1 hour on elderly patients suffering from severe acute respiratory failure, resulted in a significant improvement in blood gas analytical and clinical parameters without any side effects. An increased pulmonary recruitment, including posterior lung areas, and a reduction in spontaneous ventilatory rate have also been demonstrated with PNSV. This also paves the way to the search for the best ventilatory treatment in critically ill or ARDS patients. The compensation of intrathoracic pressures should also lead, although not yet proven, to an improvement in venous return, systolic and cardiac output. In the analysis of the study in which this method was applied, the total transpulmonary pressure delivered was the sum of the individual pressures applied by the two ventilators. However, this does not exclude the possibility of reducing the pressures of the two machines to modulate a lower but balanced total transpulmonary pressure within the chest.

Non-invasive positive ventilation in the treatment of sleep-related breathing disorders

This chapter addresses the use of long-term non-invasive positive pressure ventilation (NIPPV) (to the exclusion of continuous positive airway pressure) in the different clinical settings in which it is currently proposed: principally in diseases responsible for hypoventilation characterized by elevated PaCO(2). Nasal masks are predominantly used, followed by nasal pillow and facial masks. Mouthpieces are essentially indicated in case daytime ventilation is needed. Many clinicians currently prefer pressure-preset ventilator in assist mode as the first choice for the majority of the patients with the view of offering better synchronization. Nevertheless, assist-control mode with volume-preset ventilator is also efficient. The settings of the ventilator must insure adequate ventilation assessed by continuous nocturnal records of at least oxygen saturation of haemoglobin-measured by pulse oximetry. The main categories of relevant diseases include different types of neuromuscular disorders, chest-wall deformities and even lung diseases. Depending on the underlying diseases and on individual cases, two schematic situations may be individualized. Either intermittent positive pressure ventilation (IPPV) is continuously mandatory to avoid death in the case of complete or quasi-complete paralysis or is used every day for several hours, typically during sleep, producing enough improvement to allow free time during the daylight in spontaneous breathing while hypoventilation and related symptoms are improved. In case of complete or quasi-complete need of mechanical assistance, a tracheostomy may become an alternative to non-invasive access. In neuromuscular diseases, in kyphosis and in sequela of tuberculosis patients, NIPPV always significantly increases survival. Conversely, no data support a positive effect on survival in chronic obstructive pulmonary disease.

Sleep problems in children with common medical disorders

Sleep problems are common in many pediatric medical disorders and complicate management and patient outcomes. A wide range of conditions, including asthma, cystic fibrosis, sickle cell disease, gastroesophageal reflux, neuromuscular diseases, scoliosis, craniofacial abnormalities, obesity, and chromosomal disorders, have various sleep disturbances, including sleep-disordered breathing, ventilatory dysfunction, sleep-onset and sleep maintenance problems, and circadian rhythm disturbances. Given the adverse neurocognitive and physiologic outcomes associated with a deranged night's sleep, it is important for pediatricians to be able to anticipate, recognize, and appropriately manage these problems. This article reviews the known sleep-related problems of a few relatively common pediatric disorders.

Inpatient chronic assisted ventilatory care: a 15-year experience

STUDY OBJECTIVES

Ventilator users who are unable to leave the acute care setting may be transferred to a unit for chronic assisted ventilatory care (CAVC) with the goal of optimizing their level of function. In this report, we summarize the outcomes of all patients admitted to a CAVC unit between 1986 and 2001.

PATIENTS AND METHODS

Fifty patients (24 with neuromuscular disease [NMD], 10 with spinal cord injury [SCI], 7 with thoracic restriction [TR], 7 with COPD, and 2 with parenchymal restriction [PR]) were reviewed. Thirty-eight patients were transferred to the CAVC unit from intensive care, 5 patients were transferred from inpatient respiratory rehabilitation, 4 patients came from home, and 3 patients came from pediatric long-term care. At the time of CAVC unit admission, all patients were receiving mechanical ventilation via a tracheostomy tube.

RESULTS

Ventilator time increased gradually in patients with COPD from 16 h (SD, 5.6) to 22.9 h (SD, 3.0) per day (p < 0.05), and in patients with TR from 18.9 h (SD, 6.1) to 22.9 h (SD, 4.5) [not significant]. Five of the 10 patients with SCI were decannulated. Functional mobility, which decreased in patients with COPD and patients with TR, remained stable in NMD and PR and improved in SCI. Eighteen patients returned home or to an attendant care facility (COPD, n = 1; NMD, n = 10; SCI, n = 5; PR, n = 2); 11 patients died in the CAVC unit (COPD, n = 6; TR, n = 3; NMD, n = 1; SCI, n = 1); and 7 patients were transferred to intensive care, where they died. The average direct cost per patient per diem increased from $252 (Canadian) in 1988 to $335 in 2001.

CONCLUSION

A CAVC unit can provide a safe environment for severely impaired, ventilator-dependent individuals, many of whom (36%) left for a more independent community-based environment. Better outcomes were seen among patients with SCI and NMD than in patients with COPD and TR.

Tracheostomy and home ventilation in children

The last 30 years have brought a significant emphasis on home care for ventilator-dependent children. While the movement was driven by the desire to minimize healthcare costs, the advancements in medical knowledge and technology, and the change in the perception of a ventilator-dependent child have offered a fertile environment for the development of programs that support the chronic care of ventilator-dependent children at home (N. Engl. J. Med. 309(21) (1983) 1319; J. Pediatr. 106(5) (1985) 850; N. Engl. J. Med. 310(17) (1984) 1126; JAMA 258(23) (1987) 3398). In addition, the advances in medical and nursing care have led to the steady increase in the number of children with chronic respiratory failure and development of multi-disciplinary teams experienced and dedicated to the care of these children. Another trend that has also contributed to the rise in the number of pediatric patients using long-term mechanical ventilation is the parental expectation of long-term survival of their child. This parental expectation continues to grow as the effect of long-term mechanical ventilation on quality of life and longer survival becomes more evident. The primary indication for use of home mechanical ventilation is chronic respiratory failure (CRF) as indicated by hypoxemia and or hypercapnia. CRF is considered to be a condition persisting for greater than 1 month and requiring mechanical ventilation during part or all of the day to provide adequate gas exchange for the support of vital function (Chest 103(5) (1993) 1463).

Long term non-invasive ventilation in the community for patients with musculoskeletal disorders: 46 year experience and review

BACKGROUND

A study was undertaken to assess the long term physiological and clinical outcome in 79 patients with musculoskeletal disorders (73 neuromuscular, six of the chest wall) who received non-invasive ventilation for chronic respiratory failure over a period of 46 years.

METHODS

Vital capacity (VC) and carbon dioxide tension (PCO(2)) before and after initiation of ventilation, type and duration of ventilatory assistance, the need for tracheostomy, and mortality were retrospectively studied in 48 patients who were managed with mouth/nasal intermittent positive pressure ventilation (M/NIPPV) and 31 who received body ventilation. The two largest groups analysed were 45 patients with poliomyelitis and 15 with Duchenne's muscular dystrophy. Twenty five patients with poliomyelitis received body ventilation (for a mean of 290 months) and 20 were supported by M/NIPPV (mean 38 months). All 15 patients with Duchenne's muscular dystrophy were ventilated by NIPPV (mean 22 months).

RESULTS

Fourteen patients with poliomyelitis on body ventilation (56%) but only one on M/NIPPV, and 10 of 15 patients (67%) with Duchenne's muscular dystrophy eventually received tracheostomies for ventilatory support. Five patients with other neuromuscular disorders required tracheostomies. Twenty of 29 tracheostomies (69%) were provided because of progressive disease and hypercarbia which could not be controlled by non-invasive ventilation; the remaining nine were placed because of bulbar dysfunction and aspiration related complications. Nine of 10 deaths occurred in patients on body ventilation (six with poliomyelitis), although the causes of death were varied and not necessarily related to respiratory complications. A proportionately greater number of patients on M/NIPPV (67%) reported positive outcomes (improved sense of wellbeing and independence) than did those on body ventilation (29%, p<0.01). However, other than tracheostomies and deaths, negative outcomes in the form of machine/interface discomfort and self-discontinuation of ventilation also occurred at a rate 2.3 times higher than in the group who received body ventilation. None of the six patients with chest wall disorders (all on M/NIPPV) required tracheostomy or died. Hospital admission rates increased nearly eightfold in patients receiving body ventilation (all poliomyelitis patients) compared with before ventilation (p<0.01) while in those supported by M/NIPPV they were reduced by 36%.

CONCLUSIONS

Non-invasive ventilation (NIV) in the community over prolonged periods is a feasible although variably tolerated form of management in patients with neuromuscular disorders. While patients who received body ventilation were followed the longest (mean 24 years), the need for tracheostomy and deaths occurred more often in this group (most commonly in the poliomyelitis patients). Despite a number of discomforts associated with M/NIPPV, a larger proportion of patients experienced improved wellbeing, independence, and ability to perform daily activities.

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.

Adult spinal deformity and respiratory failure. Surgical results in 35 patients

STUDY DESIGN

Retrospective chart and complementary study review.

OBJECTIVES

To describe the features of adult patients with spinal deformity and respiratory failure and to analyze the results of surgical treatment.

SUMMARY OF BACKGROUND DATA

Many authors have studied the relation between spinal deformities and cardiorespiratory failure, but there exists little information about the benefits of reconstructive surgery in severely compromised patients.

METHODS

The charts and complementary studies of 35 adult patients surgically treated between January 1, 1978, and December 31, 1994, were reviewed. The patients were 18 years old or older (average age, 36 years). They had spinal deformity of any etiology with respiratory insufficiency as evidenced by vital capacity of less than 60% of predictive normal, PaO2 less than 80 mm Hg, or PaCO2 more than 45 mm Hg. All had reconstructive spinal surgery in an attempt to improve their respiratory problem.

RESULTS

Seven patients died within the first postoperative year, and one patient was lost to follow-up at 6 months. The other 27 patients had a mean follow-up time of 72 months. The 34 patients were divided into three groups: good, fair, and poor evolution. The patients in the good evolution group had a better preoperative general condition, had more correction of their deformities, had more improvement in their respiratory function, and had fewer complications than those in the other groups. The patients in the poor evolution group were older, had more cardiac problems, and had less correction at surgery.

CONCLUSION

The results of surgery varied from extremely good to extremely bad. The seven patients who died within the first year had no benefit, but the 27 others did very well, usually gaining significant improvement of their respiratory function. Because the alternative to surgical correction is death, this study shows that, under the right circumstances, correction of spinal deformity and, therefore, correction of respiratory function can be life-saving.

Chest wall oscillation at 1 Hz reduces spontaneous ventilation in healthy subjects during sleep

STUDY OBJECTIVE

The objective was to determine whether external chest wall oscillation (ECWO) during sleep (1) reduced spontaneous ventilation while maintaining adequate gas exchange over several hours, (2) influenced the quality and distribution of sleep, and (3) increased the number of respiratory events.

DESIGN

Prospective controlled study with counterbalanced order of intervention.

SETTING

Pulmonary function sleep laboratory.

PARTICIPANTS

Seven healthy volunteers.

INTERVENTION

One night of ECWO at 1 Hz (I:E = I:I; oscillation mean [SEM] from - 11.1 [0.7] to 6.0 [0.7] cm H2O) and a night during which the cuirass was applied without ECWO.

MEASUREMENTS AND RESULTS

ECWO resulted in a significant decrease in spontaneous minute ventilation (VE) in all stages of sleep. ECWO was associated with a reduction in the total sleep time and a reduction in rapid eye movement (REM) sleep. The number of stage changes and the sleep efficiency did not change significantly. The mean PCO2 was similar between the control and cuirass nights (44 to 46 mm Hg). There was a significant decrease in the mean PCO2 during stage 1 (41 [2] mm Hg) and stage 2 (42 [2] mm Hg) sleep during the ECWO night. The mean arterial oxygen saturation (SaO2) was maintained at 96 to 97% throughout sleep during the control, cuirass, and ECWO nights. The apnea + hypopnea index increased (p < 0.05) during ECWO mostly due to an increase in the number of hypopneas in stage 2 sleep. During ECWO, 18 of 30 respiratory events were associated with an arousal, whereas only 2 events were associated with an arousal during the control night.

CONCLUSIONS

ECWO can be tolerated for several hours and will assist ventilation while maintaining normal mean PCO2 and mean SaO2 during sleep. Monitoring of the apnea + hypopnea index and the SaO2 is recommended at the time of application. Clinical trials to define the most appropriate indications for ECWO are now necessary.

Prolonged mechanical ventilation in children

Improvements in neonatal and pediatric intensive care have produced a growing population of children dependent on mechanical ventilation for survival. Long-term mechanical ventilation has become a realistic alternative to death from progressive respiratory failure for many children with chronic respiratory illness. This article reviews the pathophysiology, etiology, and management of chronic respiratory failure in childhood.

Chronic ventilator use in osteogenesis imperfecta congenita with basilar impression: a case report

Osteogenesis imperfecta, a rare connective tissue disorder, is known to be associated sometimes with the invagination of the basilar skull. This deformity may disturb respiratory function secondary to brain stem compression and hydrocephalus. In addition, the deformed thoracic cage and fragile ribs make pulmonary care more complicated. A case of 24-year-old man is presented with brain stem compression syndrome secondary to osteogenesis imperfecta congenita with basilar impression. He developed respiratory failure and became tracheostomy positive-pressure ventilator dependent at the age of 21 years. He also suffered multiple skeletal abnormalities and mental retardation, and following the brain stem compression, severe quadriparesis. The patient's condition is stable since he has been using the ventilator and he is currently living in the community.

Use of BiPAP by nasal mask in the treatment of respiratory insufficiency in pediatric patients: preliminary investigation

A device for nasally applied bilevel positive airway pressure, BiPAP (Respironics Inc., Murrysville, PA), is currently being evaluated for the treatment of respiratory failure in pediatric and adult patients. This retrospective case review examines our experience with using BiPAP in the treatment of acute ventilatory deterioration in pediatric patients with chronic respiratory insufficiency. All patients who presented to the intensive care unit with chronic respiratory insufficiency and ventilatory failure but without hypoxia were given a trial on BiPAP. Fifteen patients, ages 4-21 years, received such ventilatory support. Four of them had cystic fibrosis (CF) and 11 had neuromuscular disease (2, spinal muscular atrophy; 7, Duchenne muscular dystrophy; 1, spinal cord injury; and 1, myopathy of undetermined origin). Hospital days, respiratory rates, resting heart rates, arterial blood gases, serum bicarbonates, and subjective assessment by parents and or patients of dyspnea, sleep pattern, and activity tolerance were compared prior to and after initiation of BiPAP. Patients were followed from 1 day to 21 months. In 14 of 15 patients placement of an artificial airway could be avoided. Significant decreases in hospital days, respiratory rate, heart rate, serum bicarbonate, and arterial PCO2 were observed after initiation of BiPAP. Decline in dyspnea (87% with severe distress at rest prior vs. 80% comfortable at rest after BiPAP), increased activity tolerance (57% attending school after BiPAP vs. none prior to BiPAP), and improved quality of sleep (93% with comfortable sleep, no daytime somnolence vs. none with comfortable sleep and 36% with daytime somnolence prior to BiPAP).(ABSTRACT TRUNCATED AT 250 WORDS)

Obstacles to discharge of ventilator-assisted children from the hospital to home

Home care for ventilatory-assisted children improves psychosocial development and reduces medical costs compared with hospital care; yet, many ventilator-assisted children remain hospitalized for lengthy periods of time after they have achieved medical stability. To identify factors that contributed to a delay in hospital discharge from the time medical stability was achieved, we reviewed the records of 54 ventilator-assisted children (age 4.6 +/- 5.9 [SD] years at discharge) who were discharged from the hospital on a regimen of home mechanical ventilation. The length of the hospitalization from which the ventilator-assisted children were initially discharged on the ventilator was 172 +/- 161 days (range, 2 to 756). The time from medical stability to discharge was 118 +/- 144 days (range, 2 to 724), or 73 percent +/- 29 percent of the total hospitalization. Fifty-one ventilator-assisted children were discharged to their natural parents' homes, and three were discharged to foster care. Once ventilator-assisted children were medically stable, it took 99 +/- 141 days for third-party payers to approve home care funding, and only 48 +/- 87 days to be discharged once funding was approved. For the 27 ventilator-assisted children with public funding, it took 184 +/- 177 days for home care funding approval, compared with 52 +/- 43 days for the 27 ventilator-assisted children with private funding (p < 0.001). Parent training took only 52 +/- 65 days. It took 369 +/- 334 days (range, 44 to 711 days) to find placement for the three ventilator-assisted children who were placed in medical foster care. In summary, ventilator-assisted children often remained hospitalized for prolonged periods of time, after they were medically stable, for nonmedical reasons. The greatest obstacle to hospital discharge was seeking approval for home care funding and for arranging out-of-home placement. Public funding agencies took significantly longer to approve home care funding than private insurance agencies.

End of life care in Duchenne muscular dystrophy

End of life care for patients with Duchenne muscular dystrophy (DMD) has become increasingly complex because of new technologies, changes in medical personnel over periods of time, emergence of home health care systems, and increasing patient and family autonomy in decision-making. In this review, we discuss the medical problems, particularly respiratory and cardiac failure, faced by DMD patients. Current concepts concerning the evaluation and options for treatment of these problems are presented as well as the ethical issues involved in the care of the DMD patient. These issues include the medical indications for treatment, patient preferences, quality-of-life issues, and contextual features related to legal, institutional, religious, geographic, cultural, social, and financial factors. We also present our experience at Loma Linda University Medical Center over the past 10 years in the development of a home mechanical ventilation program for DMD patients and an algorithm for the evaluation of these patients. Many patients with DMD do well on long-term ventilation, but some find that their quality of life is less than desirable and choose to discontinue this method of life-prolongation. Many of these new options are very expensive, making the decision to use them a difficult one. Ultimately, these are societal issues that require clear reflection on matters of resource allocation that should be performed by health care professionals, citizens, and health planners.

Decision-making in the respiratory care of amyotrophic lateral sclerosis: should home mechanical ventilation be used?

As respiratory function starts to deteriorate in those with amyotrophic lateral sclerosis, one of the principal questions that has to be answered is whether it it is appropriate to provide ventilatory support. Although expensive, it is perfectly feasible to provide this at home, and this article examines many of the issues surrounding home mechanical ventilation.

Intermittent positive pressure ventilation via the mouth as an alternative to tracheostomy for 257 ventilator users

Despite wider application of the use of nocturnal intermittent positive pressure ventilation (IPPV) via nasal access for the management of nocturnal hypoventilation, there continues to be a lack of familiarity with the use of IPPV via the mouth for ventilatory support. Unlike nasal IPPV, which is generally practical only for nocturnal use, up to 24-h mouth IPPV was the key method of noninvasive ventilatory support that permitted the avoidance or elimination of tracheostomy for 257 individuals with acute or chronic ventilatory failure. Mouth IPPV was delivered via commercially available mouthpieces for daytime aid and mouthpiece with lip seal or custom orthodontic interfaces for nocturnal support. The use of mouth IPPV alone or in a regimen with other noninvasive ventilatory aids was reviewed for these 257 individuals. Mouth IPPV was used for nocturnal aid by 163 individuals, 61 of whom had little or no measurable vital capacity or significant ventilator-free breathing time, for more than 1,560 patient-years with few complications. It was also the predominant method of daytime ventilatory support for 228 individuals for more than 2,350 patient-years. We conclude that for individuals with adequate bulbar muscle function but chronic respiratory muscle insufficiency, mouth IPPV can be an effective alternative to tracheostomy. It can significantly prolong survival while optimizing convenience, safety, and communication.

External stabilization of flail chest using continuous negative extrathoracic pressure

On rare occasions after total sternectomy, patients develop persistent flail chest deformities requiring long-term mechanical respiratory assistance. We report the use of a temporary external chest shell to deliver constant negative extrathoracic pressure (CNEP) to a long-term ventilated patient with flail chest. The patient's anterior thoracic cage stabilized, and significant improvement in pulmonary function was observed. With these data in hand, an operation was done to permanently stabilize the anterior chest wall by bone grafting.

The ventilator-assisted individual. Cost analysis of institutionalization vs rehabilitation and in-home management

The purpose of this article is to present a cost analysis of in-home vs institutionalization for severely physically disabled ventilator-assisted individuals (VAIs). Following rehabilitation and adaptation to noninvasive methods of ventilatory support, 30 VAIs were maintained in the community for 12.9 +/- 1.1 years with personal care attendants organized by a home care vendor reimbursed by New York City Medicaid. The program permitted self-directed severely disabled clients, including these 30 exclusively nontracheostomized VAIs, to live in the community and direct their attendant care and personal affairs. Prior to discharge home, the 30 patients resided in the respiratory unit of a long-term care facility for a mean of 8.9 +/- 10.1 years. The unit is currently reimbursed at a mean rate of $718.80 per patient per day. The current mean total cost of maintaining these VAIs in the community is $235.13 +/- 56.73 per patient per day. The conversion to and/or maintenance on 24-h nontracheostomy ventilatory support permitted discharge to the community by allowing the VAI to be attended by trained but uncredentialed home care attendants, thus avoiding prohibitively expensive in-home nursing for tracheostomy care. This created a savings to the public of 77 percent or $176,137 per year per client. We conclude that conversion to and/or use of noninvasive methods of ventilatory aid can be a reasonable and cost-saving goal. More respiratory rehabilitation centers are needed to free up hospital beds and facilitate discharge of VAIs to the community. There is also evidence that trained attendants should be permitted to suction tracheostomized VAIs in the home.

Alternative methods of ventilatory support for the patient with ventilatory failure due to spinal cord injury

Ventilatory insufficiency and impaired airway secretion clearance are common complications of spinal cord injury (SCI) and can lead to respiratory failure which is the leading cause of death in both the acute and chronic stages. Standard invasive management options such as intubation, tracheostomy and electrophrenic respiration have been reviewed. The review findings are consistent with our clinical experience in that these invasive options appear to entail unacceptably high morbidity and risks of mortality. A number of detailed parameters are suggested for evaluating the respiratory functioning of the individual in order to determine the most acceptable and successful noninvasive systems for both ventilatory support and evacuation of airway secretions. They are physiological substitutes for the action of the inspiratory and expiratory muscles. These techniques are described in detail. We conclude that noninvasive techniques can safely and effectively obviate the need for intubation, tracheostomy and electrophrenic pacemakers in appropriate individuals with SCI.

Amyotrophic lateral sclerosis and life-sustaining therapy: patients' desires for information, participation in decision making, and life-sustaining therapy

To identify the wishes of patients with amyotrophic lateral sclerosis (ALS) for information, participation in decision making, and life-sustaining therapy and to determine whether these wishes are stable over time, we conducted a prospective survey (baseline and 6-month follow-up interviews) of 38 consecutive patients with an established diagnosis of ALS at the University of Chicago Motor Neuron Disease Clinic. Demographic data, clinical stage of ALS, illness experience, wishes for information, and desires for participating in decisions about life-sustaining therapy were elicited. Patients readily expressed their wishes for specific information on communication aids and ventilator care for respiratory failure. Demographic, socioeconomic, and clinical characteristics did not predict patients' desires for information and decision making. The preferences for information and participation in decisions were stable during the 6-month study period, whereas preferences for cardiopulmonary resuscitation in two hypothetical circumstances were less stable. Changes were unrelated to demographic or clinical characteristics of the patients. Because many patients with ALS change their preferences for life-sustaining therapy, advance directives for end-of-life care must be reevaluated periodically.

Obstructive sleep apnea complicating negative-pressure ventilatory support in patients with chronic paralytic/restrictive ventilatory dysfunction

The purpose of this study was to determine the incidence and severity of obstructive events and oxyhemoglobin desaturation (dSaO2) in 37 patients with paralytic/restrictive ventilatory insufficiency during use of nocturnal ventilatory assistance provided by means of negative-pressure body ventilators (BVs). Thirteen of the 37 patients had mean oxyhemoglobin saturation (SaO2) less than 95 percent and a mean of ten or more episodes per hour when the dSaO2 was greater than or equal to 4 percent (4%dSaO2/h). In all, 26 of the 37 patients had evidence of significant multiple episodes of dSaO2 while asleep on BVs. Polysomnography performed on three of these patients substantiated the obstructive nature of the dSaO2. Twenty-two of the 37 patients who had a mean SaO2 of 90.6 +/- 7.2 percent and a mean of 17.7 +/- 16.1 4%dSaO2/h on BVs were switched to noninvasive ventilatory assistance by intermittent positive airway pressure (NV-PAP). Their mean SaO2 improved to 96.0 +/- 2.2 percent, and the 4%dSaO2/h decreased to 1.2 +/- 1.8 per hour. All symptoms similar to those of obstructive sleep apnea were relieved. We conclude that BV use is associated with significant dSaO2 in over 50 percent of patients. The dSaO2 is predominantly obstructive in nature but may be due to chronic underventilation in patients using less effective BVs. Patients with a mean SaO2 less than 95 percent or 10 or more 4%dSaO2/h may benefit from conversion to NV-PAP via the nose, the mouth, or an oral-nasal interface.

Intermittent abdominal pressure ventilator in a regimen of noninvasive ventilatory support

The purpose of this work is to present 640 patient-years of experience using the intermittent abdominal pressure ventilator (IAPV) in a regimen of noninvasive ventilatory support for patients with paralytic/restrictive respiratory insufficiency. Fifty-two of the 54 patients who used the IAPV used 24-hour noninvasive ventilatory support. Thirty-eight of the 52 patients could tolerate less than 15 minutes of free time off their ventilators except by the successful use of glossopharyngeal breathing (GPB). No patient, however, retained an indwelling tracheostomy and none required or used supplemental oxygen therapy. Forty-eight of the 54 patients used the IAPV for daytime support for a mean of 12.9 +/- 11.5 years (3 months to 39 years) while using other forms of noninvasive support overnight. All 48 patients maintained normal minute ventilation and end-tidal PCO2 on the IAPV. One patient used the IAPV only for nocturnal ventilatory support for six months. Five patients relied on the IAPV as their sole method of ventilatory support 24 hours a day for a mean of 13.4 +/- 11.2 years (range, 2 to 31 years). Three of these five patients had no free time and were studied by nocturnal SaO2 monitoring that demonstrated a mean SaO2 of 95 percent or greater and a minimum SaO2 of 86 percent. The maximum end-tidal PCO2 was 49 mm Hg during sleep on the IAPV. The 48 patients receiving daytime IAPV support reported few difficulties. However, two of the five patients using the IAPV 24 hours a day had development of sacral decubiti. The IAPV became ineffective for 12 patients after 12.3 +/- 9.5 years of use. These patients then switched to daytime mouth IPPV. We conclude that the IAPV is a safe and effective method of long-term daytime ventilatory support for patients with paralytic/restrictive respiratory insufficiency. Its use is optimized when employed in combination with other noninvasive methods of ventilatory support, thus eliminating the need for tracheostomy, and optimizing the use of GPB. Regular follow-up is important because the IAPV can become less effective with time.

Assisted ventilation. 5. Non-invasive and domiciliary ventilation: negative pressure techniques

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Electrophrenic ventilation: a different perspective

Since 1972, radio-frequency electrophrenic nerve pacing (EPP) has been an option for assisting the ventilation of patients with chronic paralytic respiratory insufficiency. Most of the medical literature has been favorable regarding its continued application. We reviewed the literature to determine how "successful" application of EPP was defined. Our studies indicated that long-term follow-up of EPP patients has been generally inadequate with little emphasis placed on incidence and severity of complications. There was no standardization in defining successful experiences with EPP. Upper airway instability during pacing, lack of internal pacemaker alarms, and the risk of sudden pacemaker failure necessitate permanent tracheostomy in the great majority of patients but complications of the presence of a tracheostomy were not considered in evaluating the desirability of EPP. Some EPP patients became independent of any ventilatory support thus benefiting minimally from the time commitment, effort, and extreme expense needed for EPP placement and training. We conclude that EPP is a valid option for the properly screened patient but that expense, failure rate, morbidity and mortality remain excessive and that alternative methods of ventilatory support should be explored.

Outcome of home care for technology-dependent children: success of an independent, community-based case management model

Case management is important for successful home care of technology-dependent, respiratory-disabled children. Traditionally, the medical model of hospital-based home care and case management has been used for these children. The outcome may be different from when using independent, community-based home care and case management. We evaluated the results of 28 technology-dependent children [23 receiving mechanical ventilation and 5 receiving continuous positive airway pressure (CPAP)] from 8 hospitals, who utilized an independent, community-based, case management group to coordinate home care. After 26.3 +/- 20.6 months of follow-up, 13 children (46%) remained technology-dependent, 10 (36%) were technology-independent, and 5 (18%), all with neurologic dysfunction, had died. Only one death was caused by a complication of technology. All children with congenital anomalies (n = 4), primary pulmonary disease (n = 8), and neuromuscular disease (n = 4) survived, and 9 (56%) were weaned from technological support. Children with chronic respiratory failure secondary to central neurologic dysfunction (n = 12) did poorly: 5 died, 6 remained technology-dependent, and only 1 became independent of technology. Children with neuromuscular diseases tended to use less home care nursing at a lower home care cost. Parent satisfaction was high among those who responded (82%), indicating that the child, siblings, and family were better off with the child at home. These outcomes suggest that community-based home care and case management is a reasonable alternative to the hospital-based model.

Ventilator dependency: decision-making, daily functioning and quality of life for patients with Duchenne muscular dystrophy

Ventilator assistance is offered to patients with Duchenne muscular dystrophy as an option to extend life. This paper discusses the effect of respiratory difficulties and the subsequent quality of life for 17 patients and 14 family members living in the community. Areas covered included decision-making, health, education, vocational and recreational status, community resources and life satisfaction. Activity levels before and after ventilator use were assessed. Despite restrictions in daily life both before and after ventilator use, quality of life was fairly good. Restrictions in daily life were caused by a combination of progression of the disease and the ventilator, and family members were more burdened by the ventilator than were patients. It is concluded that patients and their families should make the decision about accepting or rejecting assisted ventilation.

Noninvasive options for ventilatory support of the traumatic high level quadriplegic patient

The ventilation of 25 ventilator-dependent traumatic quadriplegic patients was supported by noninvasive means of ventilatory assistance. Twenty-four of the 25 were initially managed by endotracheal intubation, and 23 of these went on to tracheostomy intermittent positive pressure ventilation before being converted to NVA. Seventeen of the 23 patients had their tracheostomies closed. This included three patients with no significant free time except with the use of glossopharyngeal breathing. Seven of the 25 patients who used NVA for at least one year with no significant free time have employed NVA for a mean of 7.4 +/- 7.4 years (1 to 22 years). Mouth IPPV was the most common form of NVA used both during the daytime and overnight. The wrap ventilators, intermittent abdominal pressure ventilator, and GPB were also employed for long-term respiratory support. It was concluded that, in general, because of their youth, intact mental status and bulbar musculature, and absence of obstructive lung disease, patients with traumatic high level spinal cord injury are candidates to benefit from these techniques.

Decline in respiratory function and experience with long-term assisted ventilation in advanced Duchenne's muscular dystrophy

We present 17 patients with advanced DMD who required long-term assisted ventilation. Eleven patients used part-time assisted ventilation. Five of the patients received BV and/or M-IPPV or N-IPPV between two and nine years before requiring full-time T-IPPV, while six others initially used part-time T-IPPV. One patient used all three modes before requiring full-time T-IPPV. Mean (+/- SD) FVC and rebreathe PCO2 at the outset of assisted ventilation were 0.62 +/- 0.20 L and 47.4 +/- 7.5 mm Hg, respectively. Clinical features were divided between symptoms suggesting respiratory muscle fatigue and sleep-related disordered breathing. We found that, while useful in early respiratory insufficiency, BV is associated with recurrent aspiration. In our experience, N-IPPV offers the safest and most convenient form of noninvasive ventilation. When the VC has decreased to about 300 ml, most patients will require full-time ventilation; T-IPPV is advised to provide airway access to suction secretions.

Management of chronic alveolar hypoventilation by nasal ventilation

This is a study of the effect of nocturnal nasal intermittent positive pressure ventilation (NIPPV) on symptoms of chronic alveolar hypoventilation (CAH), sleep oxygen saturation (SaO2), and frequency of hospitalization of patients with progressive neuromuscular respiratory insufficiency or restrictive lung disease from thoracic wall deformity. The nocturnal use of NIPPV is explored in combination with other noninvasive methods of supported ventilation for daytime support as alternatives to tracheostomy and long-term tracheostomy intermittent positive pressure ventilation (TIPPV). Sixteen patients with less than 400 ml of vital capacity (VC) supine and less than 15 minutes of autonomous respiration (free time) maintained a mean SaO2 of 95.9 +/- 2.6 percent (SD) during sleep on NIPPV without added oxygen. Seventeen other patients with adequate free time for a sleep trial unaided had an average SaO2 of 81.8 +/- 11.0 percent which improved to 94.1 +/- 3.4 percent on NIPPV alone. The average length of use of NIPPV by the 42 patients who have used it for one month or more is 21 (3-67) months. All 34 patients who were not dependent on ventilatory support 24 hours a day demonstrated significant improvement and in most cases normalization of ABG when off aid. Thirteen patients were converted from IPPV via an endotracheal tube or TIPPV to NIPPV. Long-term use of a custom molded thermoplastic nasal interface for the delivery of NIPPV is reported for 17 patients. Unnecessary morbidity and hospitalizations can be avoided by early awareness and appropriate management of CAH. NIPPV can be an effective alternative to TIPPV, body ventilators, or oxygen therapy.

Long-term follow-up of nocturnal ventilatory assistance in patients with respiratory failure due to Duchenne-type muscular dystrophy

We followed eight patients with Duchenne-type muscular dystrophy for an average of 39 months after initiation of noninvasive intermittent ventilatory assistance using body ventilators. After one to three months of nocturnal use averaging 8 h, mean daytime PaCO2 fell from 63 +/- 2 to 45 +/- 3 mm Hg. At late follow-up, PaCO2 remained stable at 47 +/- 4 mm Hg, but vital capacity fell 33 percent compared with the initial value and the average duration of ventilator use had increased to 18 +/- 2 h daily. Three patients died and five survived; two continued using negative pressure ventilators and three had tracheostomies placed for administration of positive pressure ventilation. We conclude that noninvasive intermittent ventilatory assistance effectively reverses hypoventilation and symptoms in patients with late-stage Duchenne muscular dystrophy, but pulmonary function continues to deteriorate necessitating longer periods of ventilation, and often tracheostomy, within a few years.

Pediatric rehabilitation. 4. Disorders of the motor unit

This self-directed learning module addresses diagnostic and rehabilitation issues in children with the most common disorders of the motor unit. It is a section of the chapter on pediatric rehabilitation for the Self-Directed Medical Knowledge Program Study Guide for practitioners and trainees in physical medicine and rehabilitation. Conditions occurring only in infancy or childhood and differences in diagnostic and rehabilitation approaches as compared with those used in adults are highlighted.

Pediatric rehabilitation. 1. General principles and special considerations

This self-directed learning module addresses core concepts in the assessment of any child with disability, including physical growth and development, evolution of reflexes, and cognitive and personality development. It is a section of the chapter on pediatric rehabilitation for the Self-Directed Medical Knowledge Program Study Guide for practitioners and trainees in physical medicine and rehabilitation. The rehabilitation perspective is emphasized, especially as it changes to accommodate the developing child, with a focus on specific chronic disorders such as respiratory disease, congenital heart disease, and malignancy. These types of disorders serve as a model for the management of problems that require special medical, rehabilitative, and psychosocial consideration.

Hypercapnia in relation to pulmonary function in Duchenne muscular dystrophy

Arterialized blood gases were analyzed in 143 patients with Duchenne muscular dystrophy (DMD) to assess the relationship between forced vital capacity (FVC) and hypercapnia. The majority of patients studied had PaCO2 values in the low or normal range. Only six older patients had hypercapnia (PaCO2 greater than or equal to 45 mm Hg), and all these patients had FVC values less than or equal to 40% predicted. We conclude that hypercapnic respiratory failure occurs as a late preterminal event in DMD.

Home mechanical ventilation

Recently, interest in the use of mechanical ventilation outside the hospital setting has been increasing. Patients with various types of chronic respiratory failure may benefit from this approach. Evaluation for long-term mechanical ventilation necessitates assessment of the underlying disease process, the goals of the medical team, and the needs of the patient and family. Externally applied negative-pressure devices can provide adequate ventilation for many patients, particularly those with neuromuscular diseases. Positive-pressure ventilation by means of a tracheostomy provides greater control of the airway, allows adjustment of tidal volume and minute ventilation, and may be delivered by portable equipment. Ongoing care and support services in the home must be provided. A variety of mechanical devices and new techniques of ventilator support have made home mechanical ventilation a realistic option for long-term care.

Gated radionuclide ventriculography in the evaluation of cardiac function in Duchenne's muscular dystrophy

Left ventricular ejection fractions were determined in 38 patients with Duchenne's muscular dystrophy. No significant correlation between the severity of respiratory dysfunction or age and cardiac function was seen. We suggest that the cardiac status of each patient should be evaluated separately from his respiratory status, particularly when long-term assisted ventilation is being considered.