Unique Considerations for the Spinal Cord Injured Patient Undergoing Cardiac Surgery Utilizing Cardiopulmonary Bypass

A 37-year-old male with mitral valve regurgitation presented for mitral valve replacement. He has been a C5 quadriplegic for 13 years. The patient had been discharged 2 months before to this admission after a complicated hospital course for Staphylococcus aureus infection of the left hip. His course was complicated by adult respiratory distress syndrome (ARDS) requiring prolonged intubation, acute renal failure (ARF) requiring dialysis, 10-day coma, and bacterial endocarditis now requiring mitral valve replacement. After initial stabilization with antibiotics and gradual improvement of the multiorgan system failure, the patient presented for valve replacement and worsening congestive heart failure (CHF). Para- and quadriplegic patients rarely undergo cardiac surgery requiring cardiopulmonary bypass (CPB). The explanation for this low incidence of heart surgery in this patient population ranges from physiologic changes from the spinal cord injury to their relatively short life span. Therefore, there is no vast knowledge of how these patients with spinal cord injury will physiologically respond to CPB. Chronic paraplegia presents unique anesthetic and perfusion challenges. General anesthesia for a patient with prolonged spinal cord damage can be difficult because of dysreflexia, muscle wasting, and potassium changes with depolarizing muscle relaxants. For the perfusionist, chronic paraplegia also accentuates hemodynamic responses to nonpulsatile flow with low peripheral vascular resistance common and difficult to treat. Dramatic increases in circulating catecholamine levels are a secondary result of the initiation of CPB that can cause a hypo- and hypertensive state. Depending on the level of spinal cord injury, one might expect acute hypo- or hypertension with the various phases of open-heart surgery and CPB. A viscous circle may occur because the hypertensive state is exaggerated because of inhibitory signals not passed below the spinal cord lesion and, therefore, the vasoconstrictive reflex continues unabated. The attack usually occurs abruptly and can lead to cerebrovascular hemorrhage and death if not controlled. Fortunately, we found this patient did not develop mass autonomic dysreflexia and was not difficult to wean from CPB. The problems associated with spinal cord injury present potential complications to this patient population. Numerous triggering mechanisms may lead to a variety of clinical complications. Consideration of a response/treatment management plan for potential problems must be exercised by the surgical team

Short Crack Model Development for Primary Airframe Material - ABSTRACT ONLY

Peer reviewed: YesNRC publication: Ye

Bonded Composite Repair of Thin Metallic Materials: Variable Load Amplitude/Temperature Cycling Effects

NRC publication: Ye

PROTOTYPE INSTALLATION OF A SURFACE MOUNTABLE CRACK SENSOR - abstract only

NRC publication: Ye

Crack Detection on Composite and Metallic Aerospace Structures - Abstract Only

Peer reviewed: YesNRC publication: Ye

Effects of Ultrasonic Impact Surface Treatment on Exfoliated Aluminum Alloys - ABSTRACT ONLY

Peer reviewed: YesNRC publication: Ye

Ancrod vs. Heparin: The Resulting Effect on Oxygenator Performance During Routine Cardiopulmonary Bypass

Ancrod, a thrombin-like enzyme with anticoagulant properties, is extracted from the venom of the Malayan Pit Viper (Agkistron rhodostoma). Recently, Ancrod has been proposed as an alternate anticoagulant for cardiopulmonary bypass (CPB). In order to investigate the effect of Ancrod on the performance of the semi-porous hollow fiber membrane oxygenator now in use during CPB, in-line pressure measurements (pre- and post-oxygenator) and blood gas analysts were carried out in a clinical setting. A control group of 20 patients scheduled for coronary artery bypass grafts were coagulated with heparin and a study group of 20 patients underwent controlled defibrinogenation with Ancrod. There were no significant differences between groups with respect to blood gas values (pO2, PCO2) or pressure gradients across the membrane oxygenator and in all cases the intra-operative course was uneventful. Comparison of electron micrographs from various surfaces of the CPB circuit demonstrated less cellular and proteinaceous material were deposited on the study group's circuits than those of the patients anticoagulated with heparin. This study confirms the efficacy of Ancrod as an alternate anticoagulant for CPB

Fractographic Investigation of Boron Epoxy 5521/4 Patches

NRC publication: Ye

Equivalent Corrosion Damage Methodology for Corroded Fuselage Lap Joints

NRC publication: Ye