Use of Biofeedback in Weaning Paralyzed Patients from Respirators

Use of Biofeedback in Weaning Paralyzed Patients from Respirators" John A.Corson, Ph.D.;·· Joseph L. Grant, M.D., F.C.C.P.;t Daniel P. Moulton, e.R.T.T.; Ronald L. Green, M.D.;t and Paul T. Dunkel, R.R.T.

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Two paralyzed patients who were being treated with lmecbanical respiraton and in whom weaning with intermittent mandatory ventilation failed were treated with regular sessions of biofeedback. Their respiratory volumes were displayed to them on osdIIOKOJICI at bedside. A ,lastic
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patients with neuromuscular dysfunction have frequent respiratory crises1-4 and are often treated with mechanical respirators. Improvement may he slow and weaning prolonged and repeatedly unsuccessful, both with standard trial-and-error methods and with intermittent mandatory ventilation ( IMV). IS The present report describes two paralyzed patients in whom standard methods and IMV were used without success; both patients were successfully weaned after the use of biofeedback techniques. Biofeedback can be defined as detection and transmission back to the patient of some biologic function' that he cannot detect; the object is for the patient to gain control over the function. Biofeedback has been used in the training of patients with a variety of neuromuscular disorders.v" It has also been applied to various respiratory problems, including asthma,8.9 but not to the problem of weaning patients from respirators. CASE REPoRTS

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A 60-year-old man whose damage to the spinal cord dated from poliomyelitis in 1953 and who had a 40 pack-year history of smoking cigarettes experienced respiratory arrest on Nov 11, 1975; resuscitation and tracheostomy were performed, and mechanical ventilation with a volume-controlled °From the Veterans Administration Center, White River Junction, Vt, and D~outhMedicrA School Hanover, NH. Supported in part y grant MH 1 027:02 from the National Institutes of Mental Health, Psychiatry Education Branch. 00 Associate Professor of Psychiatry. tAssociate Professor of Clinical Medicine. tAssistant Professor of Psychiatry. Manuscript received November 17; revision accepted February 19. Reprint requests: Dr. C Of'SOO, PSflchiatf'1J, Dartmouth Medical School, Hanover, NH 03755

CHEST, 76: 5, NOVEMBER, 1979

of adhesive tape aftixed to it; the patiept had to achieve a certain tidal volume (TV) to push the tracing outside the space between the horizontal Hoes. During each session the Wpest TV achievetJ determined the taree~ TYJQ be maio_cd dorinI the next session. De :ucatio: of treatment coincid~ = ~ DDfiIa.

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respirator (Puritan-Bennett MA-l) was begun. Fluoroscopic examination showed paralysis of the right hemidiaphragm; the right lower lobe was atelectatic, and the vital capacity ( VC) was only 400 mI. Gradual weaning from the volumecontrolled respirator was nevertheless attempted using IMV, but the patient could not tolerate rates below six breaths per minute with a volume of 1 L. The arterial oxygen pressure (PaO.) was 62 mm Hg, the arterial carbon dioxide tension was 55 mm Hg, and the arterial pH was 7.42 with a fractional concentration of oxygen in the inspired gas (Flo2 ) of 0.30. Sessions of biofeedback began on Feb 2 and continued at a frequency of three or four times per week for three months. Each session lasted from 30 to 50 minutes, with an average of 40 minutes. A pneumotachygraph, inserted between the tracheostomy tube and the ventilator Y-tube, was used with an integrating amplifier to give tracings of respiratory volumes on a large oscilloscope (Sanborn 769). During sessions of biofeedback, the oscilloscope was placed at the foot of the patient's bed, where he could easily see it. Therapy with IMV was continued at six breaths per minute; and at first, biofeedback was conducted in the eight-second periods between ventilator-assisted breaths. Biofeedback was designed to increase the TV and to slow the spontaneous respiratory rate.' For training regarding volume, the oscilloscope was set to display vertical excursions only. A plastic (Plexiglas) plate on the face of the oscilloscope had two horizontal sbips of adhesive tape on it, separated by a distance reHecting the target TV. Whenever the patient breathed more deeply, he could see the tracing go outside of the space between the strips. As he improved, the strips were separated further to make the target slightly larger than the highest TV achieved during the previous session. Progress was slow, but over a period of three months, the TV was raised from less than 180 ml to over 300 ml. To help the patient slow his breathing and alter its form, the oscilloscope was set to sweep horizontally at a constant rate, and successively lower criteria were set for the number of breaths per sweep. His spirogram was initially irregular and was gradually altered by (1) specifying changes relative to the afterimage of the prior breath and by (2) drawing a picture of a normal breath on paper and asking the patient to

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DAYS SINCE START OF BIOFEEDBACK attempt to copy this picture on subsequent sweeps of the oscilloscope. By March 29, the rate of IMV had been reduced to four breaths per minute, with a corresponding increase in the duration of trials of biofeedback. The VC was consistently above 750 ml (Fig 1). For the first time the patient was able to be comfortable without respiratory assistance for as long as 15 minutes. From April 1 onward, the sessions of biofeedback were conducted without the respirator. By May 17, the VC was consistently above lL, and the patient was able to breathe without assistance for up to 15 hours. On that day, he was switched to a pressure-limited respirator (Bird Mark VII), with respirations triggered by the patient, rather than by the machine. The patient then rapidly decreased his time on the respirator; on May 22, weaning was complete.

A 54-year-old man developed weakness and partial paralysis of all four extremities, with a sensory level at C6; a diagnosis of transverse myelitis was made. On July 22, an oral endotracheal tube was inserted, and therapy with mechanical ventilation was begun with a volume-controlled respirator (Puritan-Bennett MA..l). A tracheostomy was performed on July 30. With the rate of IMV at ten breaths per minute, TV at 700 mI, and an Flo2 of 0.30, the Pa0 2 was 68 mm HI, and

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the maximum inspiratory force was -24 em H 20 . The VC was 400 mI. During the following week, initial attempts were made to reduce the rate of IMV; however, the patient was depressed over the recent death of his wife, worried about his children, and disinterested in efforts at weaning. He showed anger, refused visitors, and attempted to detach himself from the respirator. At this point, biofeedback was initiated. Communication with the patient was possible despite the tracheostomy. The electrodes of an electromyograph were applied to his forearm. Contraction produced a fusillade of electromyographic signals which both the patient and thera.. pists could hear. One burst of noise meant "yes," and two bursts meant "no." Examination of the patient's mental status confirmed his discouraged attitude but showed a level of cognitive functioning that would permit biofeedbac1c. The electromyographic feedbac1c directly encouraged the patient by showing him that some function remained in muscles he had feared were completely paralyzed. Sessions of biofeedback were conducted using a respiratory monitor (Hewlett-Packard 78202), with electrodes on the wall of the chest which detect changes in impedance and transmit them to a 6-inch oscilloscope ( Hewlett-Pac1card), providing an index of TV. Therapy with IMV was continued during the sessions of biofeedback, with the patient's selfinitiated breaths taking place between IMV-assisted breaths. For this patient the oscilloscope was set to sweep horizontal..

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CHEST, 76: 5, NOVEMBER, 1979

ly, and on the top tape a message was printed regarding the frequency of breathing. These messages took the following form: "Aim for less than two peaks per sweep," with the number of peaks adjusted downward in accord with the best perfonnance of the previous day. Each session was continued until fatigue was observed, accompanied by drop in performance. The highest VC in each session was obtained after ten minutes of practice, and the VC at the outset of each session was higher than at the outset of the prior session. After four sessions of respiratory biofeedback, the TV increased from less than 300 ml to 500 ml, the spontaneous respiratory rate dropped from 40 to 20 breaths per minute, and VC rose from 400 to 1,100 ml (Fig ~). The patient was able to breathe unassisted for 40 minutes at a time, twice daily. By Sept 20, he was able to breathe unassisted for four hours per day and was switched to therapy with a respirator (Bird Mark VII), which was discontinued on Sept 24. DISCUSSION

Before biofeedback, neither of these patients had a large enough VC to fulfill the criteria of Feeley and Hedley-Whyte 10 for anticipating successful weaning from the ventilator; their values for VC were below 5 mI/kg of body weight, instead of the recommended 10 ml/kg, During biofeedback, they gradually achieved a larger TV, and VC also rose so that at the end of biofeedback, each exceeded 10 mil kg. Without control patients, it is not possible to state with certainty that the increases in VC were due to biofeedback. Such variables as changes in nutritional status or improvement in underlying medical problems may have played important roles. The impact of psychologic support and counseling may also have been decisive (there is evidence that such psychologic issues have direct physiologic relevance to problems of weaning; for example, it has been found that depressed patients show altered carbon dioxide response curves) ;11 however, both patients received considerable psychologic support without success prior to biofeedback. Furthermore, the rapid improvement in VC (Fig 1 and 2) after the start of biofeedback is striking and suggests a cause-andeffect relationship. Our patients were both deprived of sensations normally associated with breathing. Tracheostomy and the mechanical provision of warmed humidified air deprived them of the sensation of alternate cooling and warming of the How of air at the nasopharynx, and the continuous noise of the respirator drowned out the normal sounds of breathing. The patient with transverse myelitis and a sensory level at C-6 lacked proprioceptive aflerents from the wall of the chest, which are essential to the control of voluntary breathing. Our system of bio-

CHEST, 76: 5, NOVEMBER, 1979

feedback supplied information that the patient could use to help control his breathing. We assume that the repeated practice of reaching the criteria of biofeedback increased the strength of the diaphragm and inspiratory muscles and may have had the net effect of enabling the medullary center to reinstitute automatic breathing. The availability in many hospitals of equipment which can be adapted for biofeedback should encourage its evaluation in large numbers of such patients. An appropriate preliminary baseline period will be needed to permit observation of any tendency of the underlying disease to improve, as will careful documentation of the progress of similar patients who do not receive biofeedback. ACKNOWLEDGMENTS: We are indebted to the nursing staH in the medical intensive care unit and in particular to Ms. Elizabeth Sprague, who made important conbibutions to coordination of the care of the first patient and to the organization of the data regarding his progress. We are also indebted to Robert Arnot, M.D., who suggested that we evaluate the first patient for biofeedback. REFERENCES

1 Bellamy R, Pitts FW, Stauffer ES: Respiratory complications in traumatic quadriplegia. J Neurosurg 39:596-600, 1973 2 Alba A, Soloman M, Trainor FS: Management of respiratory insufficiency in spinal cord lesions. In U.S. Veterans Administration (ed): Proceedings of the 17th Veterans Administration Spinal Cord Injury Conference. Washington, D.C., U.S. Govt Printing Office, 1971, pp 200-214 3 Bergofsky ER: Mechanism for respiratory insuHiciency after cervical cord injury. Ann Intern Med 61:435-447, 1964 4 Lipton HL, Teasdall RD: Acute transverse myelopathy in adults. Arch Neurol 28:252-257, 1973 5 Downs JB, Klein EF Jr, Desautels D, et at: Intermittent mandatory ventilation: A new approach to weaning patients from mechanical ventilators. Chest 64 :331-335, 1973 6 Basmajian JV: Electromyography comes of age. Science 176:603-609, 1972 7 Marinacci AA: The basic principles underlying neuromuscular reeducation. In Shapiro 0, Barber TX, OiCara LV, et al (eds): Biofeedback and self-control 1972: An Aldine Annual on the Regulation of Bodily Processes and consciousness. Chicago, Aldine Publishing, 1973, pp 286294 8 Feldman GM: The effect of biofeedback training on respiratory resistance of asthmatic children. Psychosom Med 38:27-34, 1976 9 Vachon L, Rich ES Jr: Visceral learning in asthma. Psychosom Med 38:122-130, 1976 10 Feeley TW, Hedley-Whyte J: Weaning from intermittent positive-pressure ventilation. N Engl J Med 292 :903-906, 1975 11 Shershow JC, Kanarek OJ, Kazem H: Ventilatory response to carbon dioxide inhalation in depression. Psychosom Med 38:282-287, 1976

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