Treatment of chronic ventilatory failure using a diaphragmatic pacemaker.

We present our series of patients with chronic ventilatory failure treated with electrophrenic respiration: 13 males and nine females with a mean age of 12 +/- 11.5 years. The etiology was, 13 tetraplegia, five sequelae of surgical treatment of intracranial lesions, and four central alveolar hypoventilation. The mean duration of the conditioning period were 3-4 months. Eighteen patients (81.8%) achieved permanent, diaphragmatically-paced breathing with bilateral stimulation and in four (18.2%) patients, pacing was only during sleep. Five patients died (22.7%): two during the hospital stay and three at home; two deaths had unknown cause and three were due respectively to, lack of at-home care, recurrence of an epidermoid tumor, and sequelae of accidental disconnection of the mechanical ventilation before beginning the conditioning period. Two cases were considered failures: One patient had transitory neurapraxia lasting 80 days, and the other had an ischemic spinal cord syndrome with progressive deterioration of the left-side response to stimulation. One patient had right phrenic nerve entrapment by scar tissue and four suffered infections. The follow-up periods since pacemaker implantation are currently: 1, 11 years; 4, 10 years, and 17, less than 5 years. The results of our experience demonstrate that complete stable ventilation can be achieved using diaphragmatic pacing and that it improves the prognosis and life quality of patients with severe chronic respiratory failure.

Transdiaphragmatic pressure in quadriplegic individuals ventilated by diaphragmatic pacemaker.

BACKGROUND: Electrophrenic pacing can be used in the management of ventilatory failure in quadriplegic patients. A study was undertaken to determine the pattern of transdiaphragmatic pressure (PDI) during the conditioning phase of electrophrenic pacing to see if it had a possible role in optimising the process of conditioning. METHODS: The tidal volume (TV) and PDI were measured in a group of six quadriplegic patients commencing ventilation by low frequency pulse stimulation (7-10 Hz) and low respiratory rate stimulation (< 10 breaths/min). RESULTS: Tidal volume increased between baseline and month 1 (4.33 ml/kg, p < 0.001) and between months 1 and 2 (3.00 ml/kg, p < 0.05) and then stabilised. PDI was higher during bilateral diaphragmatic pacing (mean (SD) 1.73 (0.30) kPa) than with either left (1.15 (0.34) kPa) or right (0.86 (0.37) kPa) unilateral pacing. PDI varied throughout the observation period, probably by interaction between recovery of the diaphragmatic fibres and the pacing regimen. CONCLUSIONS: Patients with quadriplegia due to high spinal injury can be maintained with ventilation by continuous electrophrenic pacing. The control criteria used in this study for pacing were tidal volume and the patient's tolerance, and the PDI measurement did not contribute any additional information to help with managing the conditioning process.

[Simultaneous, bilateral and permanent ventilation with a diaphragm pacing in childhood: the implantation technique and indications]. / Ventilación permanente, bilateral y simultánea con marcapasos diafragmático en la infancia: Indicaciones y técnica de implante.

The acute effects of external stimulation were well demonstrated by the turn of the century, but the chronic application had to wait until the advent of the modern pacemaker technology. Since 1983 we have implanted bilateral diaphragm pacing in ten infants and adolescents with quadriplegia and central hypoventilation syndrome. The preferred site of implantation was the thoracic phrenic nerve. The electrophysiological status of the phrenic nerve function has before been determined in all patients. We have got bilateral and continuous ventilation, in all patients, but, in quadriplegics is necessary a conditioning period. Long term stimulation of the phrenic nerves to pace the diaphragm is an effective method of ventilatory support in selected cases.