Neurovascular Changes Induced by Chemotherapy

The purpose of the present study was to test the hypothesis that doxorubicin and cyclophosphamide adjuvant chemotherapy (CHT) acutely induces neurovascular and hemodynamic changes in patients with breast cancer. To test this hypothesis, the patients were submitted in two experimental sessions, saline and chemotherapy, respectively. Saline Session. After fasting for 2 hours and abstaining from caffeine for 24 hours, the patients were positioned in a supine position. An intra-venous catheter was placed into the brachial venous in the contralateral arm of the breast surgery. Microelectrodes were positioned for MSNA measures in right leg, cuffs were placed around the leg for blood flow assessments and finger cuff was placed in 3 finger of hand for measurement of hemodynamic variables. After the instrumentation, an interval of 10 minutes was allowed, followed by blood sample collections for measurement of MPEs and, hemodynamic and neurovascular measures by period of 15 minutes (pre-infusion). Then, dexamethasone 20 mg and ondansetron 8 mg were administered i.v., followed by saline 0,09%, during 45 minutes. During saline infusion were continuously measured the neurovascular and hemodynamic variables. Finally, after saline administration, another blood sample was collected for MPEs dosing, followed by continuous measurement of hemodynamic and neurovacular variables by 15 minutes period (Figure 1).

Chemotherapy session. After a 2 to 3 day-interval, the patients were again positioned in a supine position in a temperature-controlled room (22oC). An intra-venous catheter was placed into the brachial venous in the contralateral arm of the breast surgery. Then, microelectrodes were positioned in the contralateral leg of the first session for MSNA measures. Likewise, cuffs were placed around the contralateral leg of the first protocol for blood flow assessments. After the instrumentation, an interval of 10 minutes was allowed, followed by blood sample collections and basal hemodynamic and neurovascular measures. Then, dexamethasone 20 mg and ondansetron 8 mg were administered, i.v., followed by doxorubicin and cyclophosphamide, during 45 minutes. During doxorubicin and cyclophosphamide infusions were continuously measured the neurovascular and hemodynamic variables. Finally, after doxorubicin plus cyclophosphamide administration, another blood sample was collected for EMPs dosing, followed by continuous measurement of hemodynamic and neurovacular variables by 15 minutes period