Multicenter review of diaphragm pacing in spinal cord injury

Abstract

Ventilator-dependent spinal cord-injured (SCI) patients require significant resources related to ventilator dependence. Diaphragm pacing (DP) has been shown to successfully replace mechanical ventilators for chronic ventilator-dependent tetraplegics. Early use of DP following SCI has not been described. Here, we report our multicenter review experience with the use of DP in the initial hospitalization after SCI. Under institutional review board approval for humanitarian use device, we retrospectively reviewed our multicenter nonrandomized interventional protocol of laparoscopic diaphragm motor point mapping with electrode implantation and subsequent diaphragm conditioning and ventilator weaning. Twenty-nine patients with an average age of 31 years (range, 17-65 years) with only two females were identified. Mechanism of injury included motor vehicle collision (7), diving (6), gunshot wounds (4), falls (4), athletic injuries (3), bicycle collision (2), heavy object falling on spine (2), and motorcycle collision (1). Elapsed time from injury to surgery was 40 days (range, 3-112 days). Seven (24%) of the 29 patients who were evaluated for the DP placement had nonstimulatable diaphragms from either phrenic nerve damage or infarction of the involved phrenic motor neurons and were not implanted. Of the stimulatable patients undergoing DP, 72% (16 of 22) were completely free of ventilator support in an average of 10.2 days. For the remaining six DP patients, two had delayed weans of 180 days, three had partial weans using DP at times during the day, and one patient successfully implanted went to a long-term acute care hospital and subsequently had life-prolonging measures withdrawn. Eight patients (36%) had complete recovery of respiration, and DP wires were removed. Early laparoscopic diaphragm mapping and DP implantation can successfully wean traumatic cervical SCI patients from ventilator support. Early laparoscopic mapping is also diagnostic in that a nonstimulatable diaphragm is a convincing evidence of an inability to wean from ventilator support, and long-term ventilator management can be immediately instituted. Therapeutic study, level V.