Fundamental Considerations in Pacing of the Diaphragm for Chronic Ventilatory Insufficiency: A Multi‐Center Study

Abstract

Records were reviewed of 477 patients who had diaphragm pacemakers implanted for treatment of chronic hypoventilation. Three groups were established for comparison. (1) Center group: 165 patients operated on in six medical centers participating in a cooperative study; (2) Noncenter group, sufficient data available: 203 patients operated on by surgeons with experience limited to a few cases; (3) Nonstudy group, minimal data available: 109 patients operated on as in group 2; vital statistics only were contributed. The protocol for data gathering was comprised of 154 major variables. Basic data on age, sex, diagnosis and etiology were analyzed for homogenicity of data among the groups. A comprehensive analysis of the pacing methods, complication and results from the Center group yielded information on the early experience with diaphragm pacing important to its future application.

Treatment of chronic ventilatory failure using a diaphragmatic pacemaker

“…Our series compared to those of other authors 4,9,12 had more cases of traumatic origin and tetraplegics than patients with alveolar hypoventilation. Bulbar lesions with unilateral or bilateral paralysis of the upper and/or lower vagal muscles and associated reversible or irreversible injury of cranial nerves V, VI, IX and XII produce devastating eects on the vital functions related with swallowing, breathing, and phonation; a good understanding of anatomy and function helps to establish surgical priorities in the rehabilitation of neurological disorders of the aerodigestive tract.…”

“…4,12 In our series, seven patients were under 5: three 4-yearolds, one 3-year-old, two 2-year-olds, and one 1-yearold. Five of these patients had tetraplegia and two had central alveolar hypoventilation; one of the ®ve tetraplegics died of lack of at-home care and the other four have had diaphragmatic pacing for more than 2 years.…”

“…The criteria for the implantation of the diaphragmatic pacemaker were: (1) Severe, chronic, respiratory failure requiring invasive mechanical ventilation via permanent tracheostomy on either a temporary, intermittent or continuous basis; (2) A central neurological cause: (a) alveolar hypoventilation, either primary or secondary to a brainstem disorder; (b) interruption of neuronal conduction at the upper cervical level, above the C 3 level; (3) Integrity of the intrathoracic section of the phrenic nerve; (4)Chronic respiratory failure was always accompanied by severe hypoxemia and hypercapnia requiring mechanical ventilation usually on a continuous basis, but the need for ventilatory assistance sometimes was only partial or nocturnal.…”

“…In 1966 1 they began their ®rst clinical experiments with the treatment of chronic respiratory failure using a diaphragmatic pacemaker; in 1984 2 they reported their results with continuous permanent bilateral ventilation of adults, in whom they achieved ventilation without diaphragmatic fatigue; in 1986 3 they summarized their 20 year experience; and in 1988 4 they presented the results of the ®rst multicenter study of diaphragmatic pacing, which included 477 patients. Our own experience includes a 1987 5 report of the results obtained in three patients with traumatic tetraplegia treated with implantation of a diaphragmatic pacemaker for continuous, permanent bilateral stimulation.…”

Management of respiratory problems unique to high tetraplegia

“…Multi-centre studies on diaphragm pacing 9 and on PNS 10 for respirator-dependent patients (RDP) report on 477 9 and 64 10 cases, but there are only two controlled studies comparing PNS with mechanical ventilation for RDP in spinal cord injured (SCI) patients. 11,12 In both studies, there is a trend in favour of PNS.…”