Long-term evaluation of phrenic nerve pacing for respiratory failure due to high cervical spinal cord injury

Abstract

Objectives: Phrenic nerve pacing (PNP) is a method of respiratory support that can replace mechanical ventilation (MV) in high-level cervical spinal cord injury (SCI) patients with diaphragmatic paralysis. Our objective was to evaluate survival and long-term quality of life in patients with external respiratory support by PNP vs volumetric respirator in patients with severe respiratory insufficiency due to a high-level spinal cord injury. Design: This is a retrospective review study of a prospectively collected database for evaluate the survival and a questionnaire for quality of life has been collected face-to-face or by telephone at present. Patients: Cervical SCI patients with permanent respiratory support (PNP or MV). Methods: Long-term evaluation of a cohort of PNP-supported patients. We performed a comparison between these patients and volumetric respirator-supported patients. For survival analysis, we used the Kaplan-Meier method and Cox proportional hazards model. The health-related quality of life (HRQL) was assessed with SF-36 questionnaire, a general HRQL evaluation. Results: One hundred twenty six patients on permanent respiratory support were evaluated during the study period. Of these, 38 were on PNP and 88 were mechanically ventilated. Paced patients were younger and had a longer survival, but in a multivariate analysis adjusted for age using a multiple logistic correlation we found that length of survival was greater for PNP patients. In terms of HRQL, the PNP-supported patients showed better results in terms of social functioning. Conclusions: PNP is a stable and effective method of long-term respiratory support in this type of patients (SCI patients dependent on external respiratory support). In these patients it improves the length of survival and some social issues by quality of life when compared with patients under MV.

Respiration following spinal cord injury: Evidence for human neuroplasticity

“…Phrenic nerve (PNP) and diaphragm (DP) pacing ( discussed in further detail in [EDITORS: Please cite DiMarco et al paper in this issue] ) are two strategies designed to promote ventilator independence by delivering electrical stimulation to drive diaphragmatic contraction. For some individuals, PNP and DP generate sufficient negative intra-thoracic pressure for independent ventilation, however, in only about 50% of cases (DiMarco, 2009; Onders et al, 2009; Romero et al, 2012; Weese-Mayer et al, 1996). Activity-dependent respiratory training is another method that has demonstrated success in improving rates of independent ventilation, even in those with complicated underlying pulmonary and neuromuscular conditions who have failed prior attempts at extubation (Aldrich et al, 1989; Cader et al, 2010; Martin et al, 2011).…”

Optical Stimulation for Restoration of Motor Function After Spinal Cord Injury

“…For example, phrenic pacing has allowed for individuals with high cervical injuries and intact phrenic nerves to successfully wean from mechanical ventilation, leading to increased survival rates and improved quality of life 36,37 . Additionally, Parastep ®, a commercially available device that relies on surface stimulation of the quadriceps, gluteal muscles, and peroneal nerves, permits individuals with lower SCI to ambulate for distances over a quarter of a mile 38 .…”

Can diaphragm pacing improve gas exchange? Insights from quadriplegic patients

“…Diaphragm pacing, as obtained by phrenic nerve stimulation through implanted electrodes, is a valid alternative to positive pressure mechanical ventilation (PPV) in patients with high spinal cord injuries [1]. Diaphragm pacing allows such patients to be weaned from PPV, but, to date, the respective effects of diaphragm pacing and PPV on gas exchange have not been compared.…”