The Science Journal of the American Association for Respiratory Care

2011 OPEN FORUM Abstracts


Russell E. Graham1, Darby A. Cruz2, Jeffrey Berliner2, Lisa R. Wenzel2, Craig DiTommaso2; 1Respiratory Care, Memorial Hermann - Texas Medical Center, Houston, TX; 2TIRR Memorial Hermann, Houston, TX

INTRODUCTION: Phrenic (PNS) and diaphragmatic stimulators (DS) can be successful in SCI and MS patients with respiratory failure (1,2,5); Medullary/pontine infarcts cause respiratory failure as well but few reports examine management (4). We present an application of DS in a patient with a pontine ischemia, and the protocol used to wean. SUMMARY: 56 y/o male with basilar artery thrombosis/ischemic insult to the pontine area. Patient awake, alert, with full extra-ocular movements, but unable to demonstrate voluntary control of other somatic muscles ("locked-in syndrome")He was stabilized on MV, completed rehab, and discharged home. He returned several months later, still vent dependent. We considered him for DS by fluoroscopy "sniff test" revealing asymmetric movement and severe dyscoordination of contraction, indicating functional phrenic nerve with poor coordination resulting from CNS injury. He underwent DS placement and progressive pacing protocol. DISCUSSION: He began a DS protocol consisting of 15 minutes pacing Q2H at amplitude 25 mA, pulsewidth 150 µsec, rate 12 BPM, inspiration interval 1.1, pulse frequency 17, and pulse rate 10 consistent with previously published values (1). When not being paced, the patient was maintained on full MV support. ABG and vital capacity were monitored after each pacing session, with initial ABG on vent after pacing of 7.59/26/75/4.1. He progressed on Day 3 to 20 min every other hour, with ABG of 7.45/36/74/1.2. Pacing was advanced in increments of 5 minutes per session, maintaining Q2H during the day as tolerated. Pacing was not advanced if he reported fatigue or if VC < 10% from previous baseline. By Day 13, the pacing schedule was advanced to 60 min every two hours, with ABG 7.46/36/82/1.9. Final increases were conducted at home by family for a total of 12 hrs./day consisting of six sessions of 2 hour pacing followed by 1 hour vent breaks. The goal of 12 hours per day was accomplished despite severe neurological limitations. This method allowed for steady progress and minimized complications. It prevented fatigue, did not inhibit comprehensive rehabilitation. The protocol was simple and safe. We feel this protocol may benefit other clinicians who face similar challenges. 1 Alshekhlee, al.Muscle Nerve ,2008;38:1546-1552. 2 DiMarco, A. F.Respiratory Physiology & Neurobiology, 169, 200-209. 3 Feldman, M. H.Neurology, 21 (5), 459-478. 4 Lassman, A. B. et al.Archives of Neurology, 62, 1286-1288.
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