164 Experience of the use of diaphragm pacing in patients with respiratory impairment due to motor neurone disorders

Background For patients with motor neurone disease respiratory muscle weakness is a poor prognostic sign and once the forced vital capacity reaches less than 50%, mortality at 9 months ranges from 60% to 100%. An important advance in the management of respiratory symptoms in MND has been the use of non-invasive ventilation (NIV). There are a number of issues with NIV: (1) Patients with bulbar onset MND do not tolerate NIV. (2) During the day the mask interface can interfere with communication, feeding and mobility. (3) Eventually respiratory muscle weakness progresses to a point at which NIV is ineffective. There is therefore a need for additional complementary respiratory support. Diaphragm pacing (DP) is a technique initially developed for the treatment of respiratory muscle weakness in patients with spinal cord injury. Objectives To establish the safety and feasibility of DP in patients with MND. Methods Four patients, three with MND and one with bilateral phrenic nerve palsies, were implanted with the DP device. Patients were reviewed at two monthly intervals and data on side effects, tolerability, and usage were recorded. Results All patients tolerated the general anaesthetic without complication. All patients began using the device within 24 h of implantation. All patients are alive and continue to use DP at least 12 months following surgery. In the MND group mean daily use of DP 8.7 h (SD 0.6). Discussion Insertion of diaphragmatic pacing devices in this small case series was safe. Patients tolerate daily DP use without side effects. The NIHR has awarded £1 million for a UK based randomised controlled trial of DP (DiPALS), which is due to commence autumn 2011.