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The albany medical college ventilator walker
1320
PROSTHETICSIORTHOTlCS
The Albany Medical College Ventilator
Walker
Thomas Smith, MD, George Forrest, MD, Gary Evans, MS, Rahel Kebede Johnson, MD, Nancy Chandler, PTA ABSTRACT. Smith T, Forrest G, Evans G, Johnson RK, Chandler N. The Albany Medical College Ventilator Walker. Arch Phys Med Rehabil 1996;77:1320-1. This report describes the design and use of a wheeled walker that can accommodate a ventilator and oxygen tanks. It is constructed of aluminum tubing. The front of the walker has receptacles to support a Mark 7 Bird Ventilator and oxygen tanks. The back end of the walker has a bench seat that is lifted to allow entry into the walker. The seat provides rigidity and stability to the frame of the walker. The walker has been used in the Medical Intensive Care Unit of the Albany Medical Center to facilitate early ambulation of patients who are ventilator dependent or who require a portable source of oxygen to begin ambulation training. 0 1996 by the American Congress of Rehabilitation Medicine and the American Academy of Physical Medicine and Rehabilitation
T
HE FIRST CHALLENGE to the rehabilitation team in the acute care setting is to implement a program that will prevent the development of complications that impede a patient’s full recovery of function. In the medical intensive care unit (MICU), ventilator dependence is a major impediment to mobilizing the patient. In many MICU admissions, physiatry interventions are limited. Bed confinement of the patient, who is often sedated or paralyzed, imposes limitations on the physiatrist and pulmonologist. Interventions are limited to passive range of motion and splinting to prevent decreased muscle length and remodeling of the joint capsules, sequential leg vein compression to prevent deep vein thrombosis, and rotational therapy to help compensate for the sequelae of chronic supine positioning on the respiratory and gastrointestinal systems and the integument. When the acute phase of the disease has passed, the burden of mechanical ventilation limits the patient to a bed-to-chair existence until his or her ventilatory reserve is great enough to sustain both independent ventilation and the increased metabolic requirements of ambulation. This transition often takes from many days to several weeks, during which the effects of being sedentary affect respiratory function, the cardiovascular system, and the musculoskeletal system in ways that further compromise the patient’s ability to ambulate.‘.l2 Confinement in a small room leads to sensory deprivation, anxiety, and depression.‘3-‘5 Recognizing the complications imposed by long-term mechanical ventilation, the patient care team of the MICU at the From the Department of Medicine (Dr. Smith, Johnson), the Department of Physical Medicine and Rehabilitation (Dr. Forrest, Ms. Chandler), and the Department of Clinical Engineering (Mr. Evans), Albany Medical College, Albany, NY. Submitted for publication January 3, 1996. Accepted in revised from May 13, 1996. No commercial party having a direct financial interest in the results of the research supporting this article has or will confer a benefit upon the authors or upon any organization with which the authors are associated. Reprint requests to Dr. George Forrest, Dept. of Physical Medicine and Rehabilitation, A-79, Albany Medical Center, Albany, NY 12208-3479. 0 1996 by the American Congress of Rehabilitation Medicine and the American Academy of Physical Medicine and Rehabilitation 0003-9993/96/7712-3828$3.00/O
Arch
Phys Med
Rehabil
Vol77,
December
1996
Albany Medical Center (AMC) developed a walker that incorporated a pressure-driven ventilator to facilitate early ambulation in oxygen-dependent patients in the critical care unit. This report describes the construction and application of the walker (fig 1). The MICU patient care team is comprised of nurses, physical therapists, respiratory therapists, biomedical engineers, and a physician specializing in critical care medicine. Their participation in the design ensured the multidisciplinary application of the final device. Specific concerns addressed in the design included easy access to the patient, adjustability, stability, capability to transport a fatigued patient, ventilator and oxygen tank compatibility, ballast, and strength. The first model was made from PVC pipe and duct tape. After modifications by the care team, Biomedical Engineering and Plant Management constructed the AMC Ventilated Walker. The frame of the walker is aluminum tubing set on wheels. The front handle bar is adjustable from 37” to 45”. The back frame supports a bench seat that can be lifted up to allow the patient to walk into the walker. When in place the seat fits securely, providing internal rigidity to the walker; it also makes it possible for a fatigued patient to rest or to be wheeled back to his or her room. A front horizontal bar supports a Mark 7 Bird Ventilator.” This time-cycled pressure ventilator is powered by pressure generated from E-cylinder oxygen tanks that are attached to the front corners of the walker. The tanks provide a low center of gravity to the walker, and add utility for both mechanical ventilator-dependent and oxygen-dependent patients. The frame also supports intravenous poles, infusion pumps, and an Ambu-bag. With the addition of telemetric electrocardiographic monitoring, mechanically ventilated patients can use this device when they no longer require hemodynamic monitoring. A physician order for ambulation and ventilator parameters is required before a patient uses the walker. A respiratory care practitioner familiar with the Mark 7 Ventilator, and physical therapy and nursing staff personnel, are present for the patient’s first efforts. If the patient is successful in ambulating with the walker, subsequent use can be initiated by any member of the care team; a respiratory care practitioner checks the ventilator calibration before each use. Practical application of the AMC Ventilator Walker is demonstrated by this report of the first patient who used it. CASE REPORT A 69-year-old woman was admitted for elective coronary bypass graft to correct unstable angina pectoris. The surgery was complicated because of difficulty in weaning the patient from mechanical ventilation. The respiratory difficulty was due to significant obesity, left hemi-diaphram paralysis, persistent congestive heart failure, persistent left lower lobe atelectasis, and obstruction of air Aow by secretions. One month after surgery, she required a tracheostomy. Two days after tracheostomy her negative inspiratory force was only -18cm of Hz0 with spontaneous to tidal volume of 2OOcc (2cc/kg). Her respiratory rate was 30 on pressure support ventilation, PSV of 4cm HzO. She was being maintained on PSV 18cm Hz0 and 40% FIO~. The physical therapy evaluation recorded strength at 3/5 in all extremities. She required maximum assist of one to move from
ALBANY
MEDICAL
COLLEGE
VENTILATOR
WALKER,
1321
Smith
the AMC O2 walker, and, therefore, it provides increased support for a patient with decreased balance. The AMC Ventilator Walker has a seat that allows the patient to rest or, if necessary, to be transported back to his or her room. The first application of the AMC Ventilator Walker demonstrates the utility of the device in facilitating ambulation in a ventilator dependent patient with multiple medical problems requiring MICU care. The deconditioning and multiple medical problems resulting from bed confinement may be prevented by early ambulation of the MICU patient.“.18 The sequelae of depression and anxiety resulting from long-term confinement may be reduced by a device that allows the patient to leave his or her small room in the MICU. Patients are often initially afraid to attempt to use the walker, but once they safely ambulate with it, they usually look forward to escaping from their beds and their rooms. The ventilator walker can be an important adjunct in the care of MICU patients.
Fig 1. The Albany
Medical
College
Ventilator
Walker.
sit to stand. The physical therapist noted that the patient’s ambulation was compromised by her respiratory status, balance, and weakness. The patient was also diagnosed as being anxious and depressed. Two days posttracheostomy, the care plan was modified to include ambulation in the AMC Ventilated Walker. With a respiratory care practitioner adjusting the Ventilator to patient comfort, the patient was assisted in walking by her physical therapist and her primary nurse. She walked a total of 160 feet, stopping twice to sit on the seat of the walker during the therapy session. With the assistance of physical therapy and nursing she used the walker two times a day. One week later assessment by the patient’s physical therapist documented significant improvement. She could come sit to stand independently. Her balance, static and dynamic, was graded as good. She was able to ambulate 200 feet with the walker and with minimal assistance. There was improvement in her affect. Twenty-seven days after the tracheostomy she was using a trach collar 20 hours a day and was able to ambulate independently for 300 feet using the walker. During the next week ventilator support was weaned to continuous positive airway pressure and then to supplemental nasal oxygen. At the time of discharge she utilized Bipap support at night, and she was able to ambulate independently with a standard walker and nasal OZ. Five months after the initial surgery she was able to walk independently without assistive device or supplemental oxygen,
DISCUSSION Kirshblum and BachI developed and described a walker that could accommodate a ventilator. The design of the AMC Ventilator Walker is significantly different from that described by Kirshblum and Bach. The AMC Ventilator Walker can accommodate oxygen tanks or a ventilator. The patient is enclosed in
References 1. Muller EA. Influence of training and of inactivity on muscle strength. Arch Phys Med Rehabil 1970;51:449-62. 2. Williams PE. Use of intermittant stretch in the prevention of serial sarcomere loss in immobilized muscle. Ann Rheum Dis 1990:49: 316-7. 3. Spector SA, Simard CP, Fournier M, Stemlicht E, Edgerton VR. Architectural alterations of rat hind-limb skeletal muscles immobilized at different lengths. Exp Neurol 1982;76:94-110. 4. Akeson WH, Amielo INGD, Abel MR, Garfin SR, Woo S. Effects of immobilization on joints. Clin Orthop 1987;219:28-37. 5. Krolner B, Toft B. Vertebral bone loss: an untreated side effect of therapeutic bed rest. Clin Sci 1983;64:537-46. 6. Deitrick JE, Whedon DG, Shorr E. Effects of immobilization upon various metabolic and physiologic functions of normal men. Am J Med 1948;4:3-32. I. Harper CM, Lyes YM. Physiology and complications of bed rest. J Am Geriatr Sot 1988; 36: 1047-54. 8. Hung .I, Goldwater D, Convertino VA, McKillop JH, Goris ML, DeBusk RF. Mechanisms for decreased exercise capacity after bed rest in normal middle-aged men. Am J Cardiol 1983;51:344-7. 9. Convertino V, Hung J, Goldwater D, DeBusk RF. Cardiovascular responses to exercise in middle-aged men after 10 days of bed rest. Circulation 1982;65: 134-40. 10. Kudsk KA, Fabian TC, Baum S, Gold RE, Mangiante E, Voeller G. Silent deep vein thrombosis in immobilized multiple trauma patients. Am J Surg 1989; 158:515-9. 11. Farfeduddin K. Abelman WH. Imoaired orthostatic tolerance after bed rest in patients with myocardial infarction. N Engl J Med 1969; 280:345-50. 12. Haines RF. Effect of bed rest and exercise on body balance. J Appl Physiol 1974;36:323-7. 13 Miller M. Iatrogenic and nursigenic effects of prolonged immobilization of the ill aged. J Am Geriatr Sot 1975;23:360-9. 14. Harper CM, Lyle; YM. Physiology and complicatons on bed rest. J Am Geriatr Sot 1988:36:1047-54. 15. Downs FS. Bedrest and sensory disturbances. Am J Nursing 1974; 74:434-8. 16 Kirshblum SC, Bach JR. Walker modification for ventilator-assisted individuals. Am J Phvs Med Rehabil 1992:71:304-6. 17 Canavarro K. Early p&t-operative ambulation. Ann Surg 1946; 124: 180-l. 18 Newburger B. Early post-operative walking. Surgery 1943; 14:14254.
a. Bird
Products
Co.,
El Alejo
Arch
Supplier Road, Palm
Phys Med
Springs,
Rehabil
Vol77,
GA
92262
December
1996
PROSTHETICSIORTHOTlCS
The Albany Medical College Ventilator
Walker
Thomas Smith, MD, George Forrest, MD, Gary Evans, MS, Rahel Kebede Johnson, MD, Nancy Chandler, PTA ABSTRACT. Smith T, Forrest G, Evans G, Johnson RK, Chandler N. The Albany Medical College Ventilator Walker. Arch Phys Med Rehabil 1996;77:1320-1. This report describes the design and use of a wheeled walker that can accommodate a ventilator and oxygen tanks. It is constructed of aluminum tubing. The front of the walker has receptacles to support a Mark 7 Bird Ventilator and oxygen tanks. The back end of the walker has a bench seat that is lifted to allow entry into the walker. The seat provides rigidity and stability to the frame of the walker. The walker has been used in the Medical Intensive Care Unit of the Albany Medical Center to facilitate early ambulation of patients who are ventilator dependent or who require a portable source of oxygen to begin ambulation training. 0 1996 by the American Congress of Rehabilitation Medicine and the American Academy of Physical Medicine and Rehabilitation
T
HE FIRST CHALLENGE to the rehabilitation team in the acute care setting is to implement a program that will prevent the development of complications that impede a patient’s full recovery of function. In the medical intensive care unit (MICU), ventilator dependence is a major impediment to mobilizing the patient. In many MICU admissions, physiatry interventions are limited. Bed confinement of the patient, who is often sedated or paralyzed, imposes limitations on the physiatrist and pulmonologist. Interventions are limited to passive range of motion and splinting to prevent decreased muscle length and remodeling of the joint capsules, sequential leg vein compression to prevent deep vein thrombosis, and rotational therapy to help compensate for the sequelae of chronic supine positioning on the respiratory and gastrointestinal systems and the integument. When the acute phase of the disease has passed, the burden of mechanical ventilation limits the patient to a bed-to-chair existence until his or her ventilatory reserve is great enough to sustain both independent ventilation and the increased metabolic requirements of ambulation. This transition often takes from many days to several weeks, during which the effects of being sedentary affect respiratory function, the cardiovascular system, and the musculoskeletal system in ways that further compromise the patient’s ability to ambulate.‘.l2 Confinement in a small room leads to sensory deprivation, anxiety, and depression.‘3-‘5 Recognizing the complications imposed by long-term mechanical ventilation, the patient care team of the MICU at the From the Department of Medicine (Dr. Smith, Johnson), the Department of Physical Medicine and Rehabilitation (Dr. Forrest, Ms. Chandler), and the Department of Clinical Engineering (Mr. Evans), Albany Medical College, Albany, NY. Submitted for publication January 3, 1996. Accepted in revised from May 13, 1996. No commercial party having a direct financial interest in the results of the research supporting this article has or will confer a benefit upon the authors or upon any organization with which the authors are associated. Reprint requests to Dr. George Forrest, Dept. of Physical Medicine and Rehabilitation, A-79, Albany Medical Center, Albany, NY 12208-3479. 0 1996 by the American Congress of Rehabilitation Medicine and the American Academy of Physical Medicine and Rehabilitation 0003-9993/96/7712-3828$3.00/O
Arch
Phys Med
Rehabil
Vol77,
December
1996
Albany Medical Center (AMC) developed a walker that incorporated a pressure-driven ventilator to facilitate early ambulation in oxygen-dependent patients in the critical care unit. This report describes the construction and application of the walker (fig 1). The MICU patient care team is comprised of nurses, physical therapists, respiratory therapists, biomedical engineers, and a physician specializing in critical care medicine. Their participation in the design ensured the multidisciplinary application of the final device. Specific concerns addressed in the design included easy access to the patient, adjustability, stability, capability to transport a fatigued patient, ventilator and oxygen tank compatibility, ballast, and strength. The first model was made from PVC pipe and duct tape. After modifications by the care team, Biomedical Engineering and Plant Management constructed the AMC Ventilated Walker. The frame of the walker is aluminum tubing set on wheels. The front handle bar is adjustable from 37” to 45”. The back frame supports a bench seat that can be lifted up to allow the patient to walk into the walker. When in place the seat fits securely, providing internal rigidity to the walker; it also makes it possible for a fatigued patient to rest or to be wheeled back to his or her room. A front horizontal bar supports a Mark 7 Bird Ventilator.” This time-cycled pressure ventilator is powered by pressure generated from E-cylinder oxygen tanks that are attached to the front corners of the walker. The tanks provide a low center of gravity to the walker, and add utility for both mechanical ventilator-dependent and oxygen-dependent patients. The frame also supports intravenous poles, infusion pumps, and an Ambu-bag. With the addition of telemetric electrocardiographic monitoring, mechanically ventilated patients can use this device when they no longer require hemodynamic monitoring. A physician order for ambulation and ventilator parameters is required before a patient uses the walker. A respiratory care practitioner familiar with the Mark 7 Ventilator, and physical therapy and nursing staff personnel, are present for the patient’s first efforts. If the patient is successful in ambulating with the walker, subsequent use can be initiated by any member of the care team; a respiratory care practitioner checks the ventilator calibration before each use. Practical application of the AMC Ventilator Walker is demonstrated by this report of the first patient who used it. CASE REPORT A 69-year-old woman was admitted for elective coronary bypass graft to correct unstable angina pectoris. The surgery was complicated because of difficulty in weaning the patient from mechanical ventilation. The respiratory difficulty was due to significant obesity, left hemi-diaphram paralysis, persistent congestive heart failure, persistent left lower lobe atelectasis, and obstruction of air Aow by secretions. One month after surgery, she required a tracheostomy. Two days after tracheostomy her negative inspiratory force was only -18cm of Hz0 with spontaneous to tidal volume of 2OOcc (2cc/kg). Her respiratory rate was 30 on pressure support ventilation, PSV of 4cm HzO. She was being maintained on PSV 18cm Hz0 and 40% FIO~. The physical therapy evaluation recorded strength at 3/5 in all extremities. She required maximum assist of one to move from
ALBANY
MEDICAL
COLLEGE
VENTILATOR
WALKER,
1321
Smith
the AMC O2 walker, and, therefore, it provides increased support for a patient with decreased balance. The AMC Ventilator Walker has a seat that allows the patient to rest or, if necessary, to be transported back to his or her room. The first application of the AMC Ventilator Walker demonstrates the utility of the device in facilitating ambulation in a ventilator dependent patient with multiple medical problems requiring MICU care. The deconditioning and multiple medical problems resulting from bed confinement may be prevented by early ambulation of the MICU patient.“.18 The sequelae of depression and anxiety resulting from long-term confinement may be reduced by a device that allows the patient to leave his or her small room in the MICU. Patients are often initially afraid to attempt to use the walker, but once they safely ambulate with it, they usually look forward to escaping from their beds and their rooms. The ventilator walker can be an important adjunct in the care of MICU patients.
Fig 1. The Albany
Medical
College
Ventilator
Walker.
sit to stand. The physical therapist noted that the patient’s ambulation was compromised by her respiratory status, balance, and weakness. The patient was also diagnosed as being anxious and depressed. Two days posttracheostomy, the care plan was modified to include ambulation in the AMC Ventilated Walker. With a respiratory care practitioner adjusting the Ventilator to patient comfort, the patient was assisted in walking by her physical therapist and her primary nurse. She walked a total of 160 feet, stopping twice to sit on the seat of the walker during the therapy session. With the assistance of physical therapy and nursing she used the walker two times a day. One week later assessment by the patient’s physical therapist documented significant improvement. She could come sit to stand independently. Her balance, static and dynamic, was graded as good. She was able to ambulate 200 feet with the walker and with minimal assistance. There was improvement in her affect. Twenty-seven days after the tracheostomy she was using a trach collar 20 hours a day and was able to ambulate independently for 300 feet using the walker. During the next week ventilator support was weaned to continuous positive airway pressure and then to supplemental nasal oxygen. At the time of discharge she utilized Bipap support at night, and she was able to ambulate independently with a standard walker and nasal OZ. Five months after the initial surgery she was able to walk independently without assistive device or supplemental oxygen,
DISCUSSION Kirshblum and BachI developed and described a walker that could accommodate a ventilator. The design of the AMC Ventilator Walker is significantly different from that described by Kirshblum and Bach. The AMC Ventilator Walker can accommodate oxygen tanks or a ventilator. The patient is enclosed in
References 1. Muller EA. Influence of training and of inactivity on muscle strength. Arch Phys Med Rehabil 1970;51:449-62. 2. Williams PE. Use of intermittant stretch in the prevention of serial sarcomere loss in immobilized muscle. Ann Rheum Dis 1990:49: 316-7. 3. Spector SA, Simard CP, Fournier M, Stemlicht E, Edgerton VR. Architectural alterations of rat hind-limb skeletal muscles immobilized at different lengths. Exp Neurol 1982;76:94-110. 4. Akeson WH, Amielo INGD, Abel MR, Garfin SR, Woo S. Effects of immobilization on joints. Clin Orthop 1987;219:28-37. 5. Krolner B, Toft B. Vertebral bone loss: an untreated side effect of therapeutic bed rest. Clin Sci 1983;64:537-46. 6. Deitrick JE, Whedon DG, Shorr E. Effects of immobilization upon various metabolic and physiologic functions of normal men. Am J Med 1948;4:3-32. I. Harper CM, Lyes YM. Physiology and complications of bed rest. J Am Geriatr Sot 1988; 36: 1047-54. 8. Hung .I, Goldwater D, Convertino VA, McKillop JH, Goris ML, DeBusk RF. Mechanisms for decreased exercise capacity after bed rest in normal middle-aged men. Am J Cardiol 1983;51:344-7. 9. Convertino V, Hung J, Goldwater D, DeBusk RF. Cardiovascular responses to exercise in middle-aged men after 10 days of bed rest. Circulation 1982;65: 134-40. 10. Kudsk KA, Fabian TC, Baum S, Gold RE, Mangiante E, Voeller G. Silent deep vein thrombosis in immobilized multiple trauma patients. Am J Surg 1989; 158:515-9. 11. Farfeduddin K. Abelman WH. Imoaired orthostatic tolerance after bed rest in patients with myocardial infarction. N Engl J Med 1969; 280:345-50. 12. Haines RF. Effect of bed rest and exercise on body balance. J Appl Physiol 1974;36:323-7. 13 Miller M. Iatrogenic and nursigenic effects of prolonged immobilization of the ill aged. J Am Geriatr Sot 1975;23:360-9. 14. Harper CM, Lyle; YM. Physiology and complicatons on bed rest. J Am Geriatr Sot 1988:36:1047-54. 15. Downs FS. Bedrest and sensory disturbances. Am J Nursing 1974; 74:434-8. 16 Kirshblum SC, Bach JR. Walker modification for ventilator-assisted individuals. Am J Phvs Med Rehabil 1992:71:304-6. 17 Canavarro K. Early p&t-operative ambulation. Ann Surg 1946; 124: 180-l. 18 Newburger B. Early post-operative walking. Surgery 1943; 14:14254.
a. Bird
Products
Co.,
El Alejo
Arch
Supplier Road, Palm
Phys Med
Springs,
Rehabil
Vol77,
GA
92262
December
1996