Heart Brain Disconnect26 Apr

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Heart Brain Disconnect26 Apr

  1. 1. HEART-BRAIN DISCONNECT: ASYSTOLE COMPLICATING CERVICAL SPINE INJURY CPT Erik Manninen, MC (Associate), MAJ Alex Truesdell, MC (Associate) Walter Reed Army Medical Center, Washington, D.C. <ul><li>CLINICAL PRESENTATION </li></ul><ul><li>HPI: 24-year-old white male soldier serving in Iraq </li></ul><ul><ul><li>High velocity gunshot wound to the neck </li></ul></ul><ul><ul><li>C2 / C3 fractures, C2 spinal cord transection </li></ul></ul><ul><ul><li>Emergent field cricothyroidotomy </li></ul></ul><ul><ul><li>Spinal shock at Combat Support Hospital </li></ul></ul><ul><ul><li>Transferred to Walter Reed for definitive care </li></ul></ul><ul><li>PMH: None </li></ul><ul><li>PSH: As above </li></ul><ul><li>ALL: NKDA </li></ul><ul><li>MEDS: Empiric IV ampicillin/sulbactam </li></ul><ul><li>PHYSICAL EXAM </li></ul><ul><li>BP 117/54, HR 64, T 102F, SaO2 94% </li></ul><ul><li>GCS 11T, no sensation, movement below mid-neck </li></ul><ul><li>Volume assist-control ventilation, lungs clear to auscultation bilaterally </li></ul><ul><li>Regular cardiac rate and rhythm </li></ul><ul><li>Bowel sounds present, abdomen soft, no hepatosplenomegaly </li></ul><ul><li>HOSPITAL COURSE </li></ul><ul><li>Antibiotic coverage broadened to meropenem, piperacillin/tazobactam, and vancomycin </li></ul><ul><li>30-second episode of self-limited asystole associated with a bowel movement </li></ul><ul><li>Multiple subsequent asystolic episodes related to urinary catheter obstruction, tracheal suctioning, and brief disconnection from the ventilator </li></ul><ul><li>Several asystolic episodes aborted spontaneously–most required the administration of intravenous atropine </li></ul><ul><li>RADIOLOGY </li></ul><ul><li>CT Head: No intracranial abnormalities </li></ul><ul><li>CT C-Spine: Fracture of C2 / C3, partial cervical cord transection, mandible fracture, no retained metal fragments </li></ul><ul><li>4-Vessel Angiography: no vascular damage, no compromise of cerebral blood flow </li></ul>Treatment Currently, no treatments are successful at reconnecting the disrupted autonomic pathways. The resultant bradycardia and asystole are commonly treated with episodic atropine—or an alternative vagolytic. The preferred treatment is primary prevention of the inciting stimuli. As examples, bladder distention may be avoided via frequent intermittent catheterizations, foley obstruction can be prevented through regular catheter maintenance, and administration of high flow oxygen prior to suctioning may limit inciting hypoxic episodes. <ul><li>FOLLOW UP </li></ul><ul><li>With increased staff awareness and institution of preventive measures the patient experienced no further recurrence of asystolic episodes during the remainder of his hospital stay </li></ul><ul><li>CLINICAL RELEVANCE </li></ul><ul><li>Cervical spinal cord injury and the subsequent unopposed parasympathetic output place young, otherwise healthy, trauma patients at risk for significant morbidity and mortality from arrhythmia. </li></ul><ul><li>Increased clinician awareness of provocative stimuli coupled with the institution of aggressive preventive measures may radically reduce unconstrained parasympathetic discharge and hemodynamically significant, and possibly fatal, bradycardia or asystole. </li></ul><ul><li>REFERENCES </li></ul><ul><li>Blackmer J. Rehabilitation medicine: 1. Autonomic dysreflexia. CMAJ. 2003; 169 (9):931-35. </li></ul><ul><li>Bilello JF, Davis JW, Cunningham MA, Groom TF, Lemaster D, Sue LP. Cervical spinal cord injury and the need for cardiovascular intervention. Arch Surg. 2003;138:1127-29. </li></ul><ul><li>3. Dixit S. Bradycardia associated with high cervical spinal cord injury. Surg Neurol. 1995;43:514. </li></ul><ul><li>Pasnorri VR, Leesar MA. Use of aminophylline in the treatment of severe symptomatic bradycardia resistant to atropine. Cardiology in review. 2004;12 (2):65-68. </li></ul>AUTONOMIC NERVOUS SYSTEM AND CERVICAL CORD INJURY Pathogenesis Normally, sympathetic outflow to the heart occurs via preganglionic fibers exiting the spinal cord at thoracic levels T1 through T4 while parasympathetic innervation to the heart occurs via the vagus nerve, which exits the CNS at the level of the medulla. With complete cervical cord transection, descending sympathetic fibers to the viscera are interrupted, whereas descending parasympathetic fibers remain intact. Clinical Manifestations In the absence of a compensatory sympathetic signal, catastrophic bradycardia or asystole may result from common, normally benign, parasympathetic stimuli—such as bowel movements, bladder fullness, postural changes, or tracheal suctioning. <ul><li>DIAGNOSIS </li></ul><ul><li>Bradycardia / asystole secondary to increased vagal tone in the absence of a compensatory sympathetic signal </li></ul><ul><li>TREATMENT </li></ul><ul><li>Prevention is preferable to treatment </li></ul><ul><li>Aminophylline has demonstrated success in atropine resistant bradycardia in lieu of transcutaneous or transvenous pacing </li></ul>Blackmer J. Rehabilitation medicine: 1. Autonomic dysreflexia. CMAJ. 2003; 169 (9):931-35.

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