Mechanical ventilation or phrenic nerve stimulation for treatment of spinal cord injury-induced respiratory insufficiency

Abstract

Study design: Prospective clinical study of two treatments. Objective: To compare mechanical ventilation (MV) with phrenic nerve stimulation (PNS) for treatment of respiratory device-dependent (RDD) spinal cord-injured (SCI) patients. Setting: Department for spinal cord-injured patients of an insurance-company-run trauma hospital in Hamburg, Germany. Methods: Prospective data collection of treatment-related data over 20 years. Results: In total, 64 SCI-RDD patients were treated during the study period. Of these, 32 of the patients with functioning phrenic nerves and diaphragm muscles were treated with PNS and 32 patients with destroyed phrenic nerves were mechanically ventilated. Incidence of respiratory infections (RIs per 100 days) prior to use of final respiratory device was equal in both groups, that is (median (interquartile range)) 1.43 (0.05-3.92) with PNS and 1.33 (0.89-2.21) with MV (P ¼ 0.888); with final device in our institution it was 0 (0-0.92) with PNS and 2.07 (1.49-4.19) with MV (Po0.001); at final location it was 0 (0-0.02) with PNS and 0.14 (0-0.31) with MV (Po0.001). Thus, compared to MV, respiratory treatment with PNS significantly reduces frequency of RI. Quality of speech is significantly better with PNS. Nine patients with PNS, but only two with MV, were employed or learned after rehabilitation (P ¼ 0.093). The primary investment in the respiratory device is higher with PNS, but it can be paid off in our setting within 1 year because of the reduced amount of single use equipment, easier nursing and fewer RIs compared to MV. Conclusions: PNS instead of MV for treatment of SCI-RDD reduces RIs, running costs of respiratory treatment and obviously improves patients' quality of life.

Survival after short- or long-term ventilation after acute spinal cord injury: a single-centre 25-year retrospective study

“…It has been of considerable interest whether diaphragmatic pacing offers survival advantages over mechanical ventilation 14 and some indication that this is so is provided by analysing these subgroups separately, although the relatively small numbers do not allow the nearly 2-year difference in survival within each age group to reach statistical significance (Table 6). …”

Phrenic Nerve Pacing: Current Concepts

“…Electromyography (EMG) of the diaphragm during tidal breathing or after phrenic nerve stimulation is limited by technical issues of electrode placement, "crosstalk" from adjacent muscle groups, and variable distance of electrodes to muscle related to subcutaneous thickness when electrodes are placed at standardized places like seventh and ninth intercostal spaces (4,18).…”

“…Overall, patients with SCI treated with phrenic nerve pacing instead of standard mechanical ventilation experienced less airway infections, had reduced costs for single use airway equipment, had improved the quality of speech, had improved quality of life, and probably derived a mortality benefit (18).…”

“…When costs of a respiratory infection are incorporated in the cost analysis, the diaphragm pacing becomes more cost effective in 1 year. (18).…”

“…Diaphragm pacing is a technique of artificial ventilation using electrical stimulation of the phrenic nerves to produce diaphragm contraction, providing many ventilator-dependent tetraplegic patients with freedom from mechanical ventilation (16,17,18,19). Compared with mechanical ventilation, phrenic pacing provides more natural breathing dynamics, reduces the occurrence of respiratory infection, and improves quality of life.…”