Abstract
BACKGROUND: Long-term mechanical ventilation is often required following high spinal cord injury. Direct diaphragm pacing offers potential alternative ventilatory support in selected cases involving laparoscopic electrode implantation into the diaphragm’s abdominal surface. Reported benefits include improved quality of life and reduced healthcare utilisation with low rates of serious complications. This project aims to describe outcomes of patients assessed by our direct diaphragm pacing program and ability of pre-operative tests to predict successful diaphragm pacing. METHODS: Retrospective review of cases assessed between 2009-2024 will describe demographics, comorbidities, clinical outcomes (including dyspnoea scores, pacing utilisation, speech facilitation and achieved tidal volumes) and complications using non-parametric methods. Pre-operative tests include MRI spine and combined diaphragm assessment: phrenic nerve conduction studies with simultaneous measurement of diaphragm EMG and fluoroscopic response. Their relation to successful intraoperative stimulation of each hemidiaphragm and clinical outcomes will be assessed via Chi-squared testing, describing proportions for each category. PROGRESS TO DATE: Literature review, protocol, power calculations and ethics application are complete. Preliminary data indicates nerve conduction studies and diaphragm screening closely relate to successful intraoperative pacing. Fluoroscopy could identify successful cases where nerve conduction indicated impairment. INTENDED OUTCOME AND IMPACT: With worldwide variation in approach, our study will describe the utility of protocol screening elements in relation to technical and clinical outcomes. Findings may be hypothesis-generating, informing future research towards improving ability to identify those who may benefit from direct diaphragm pacing and reduce unnecessary procedures in a vulnerable patient group with high healthcare utilisation risk.