Effect of Transcranial Direct Current Brain Stimulation of the Motor Cortex on Chemotherapy-Induced Nausea and Vomiting in Female Patients with Breast Cancer.

OBJECTIVE: Chemotherapy-induced nausea and vomiting (CINV) is an adverse outcome associated with chemotherapy and is sometimes difficult to manage. This study aimed to examine the impact of a single session of transcranial direct current brain stimulation (tDCS; 2 mA) over the motor cortex for 20 minutes before chemotherapy in patients receiving a highly emetogenic chemotherapy. STUDY DESIGN: Prospective randomized double-blind sham-controlled study. SETTING: Academic medical center. METHOD: Sixty patients with breast cancer who were scheduled for chemotherapy treatment were selected and allocated randomly into two equal groups: a stimulation group and a sham group. tDCS was implemented over the primary motor area (M1) (2 mA) for 20 minutes. Patients' nausea was measured by a cumulative index of nausea, a visual analog scale for nausea (VAS-N), episodes of vomiting, and the Edmonton Symptoms Assessment Scale (ESAS) to assess symptoms like pain, malaise, and sense of well-being. Evaluation was done before stimulation and every 24 hours for 72 hours after the end of infusion of chemotherapy. RESULTS: The tDCS group showed a reduction in the cumulative index of nausea (P < 0.001, F = 50), the VAS-N (P < 0.001, F = 52), the ESAS malaise score (P < 0.001, F = 37.6), and the sense of well-being score (P < 0.001, F = 25) vs the sham group. Six patients (20%) in the tDCS group required rescue antiemtic therapy vs 14 patients (46.7%) in the sham group (P < 0.028). CONCLUSION: A single session of M1 tDCS is suggested as an effective adjuvant therapy to control CINV in female patients suffering from breast cancer and receiving highly emetogenic chemotherapy. Corroboratory studies are needed.

Effect of Dexmedetomidine Added to Modified Pectoral Block on Postoperative Pain and Stress Response in Patient Undergoing Modified Radical Mastectomy.

BACKGROUND: The most common surgical procedure for breast cancer is the modified radical mastectomy (MRM), but it is associated with significant postoperative pain. Regional anesthesia can reduce the stress response associated with surgical trauma. OBJECTIVES: Our aim is to explore the efficacy of 1 µg/kg dexmedetomedine added to an ultrasound (US)-modified pectoral (Pecs) block on postoperative pain and stress response in patients undergoing MRM. STUDY DESIGN: A randomized, double-blind, prospective study. SETTING: An academic medical center. METHODS: Sixty patients with American Society of Anesthesiologists (ASA) physical status I-II (18-60 years old and weighing 50-90 kg) scheduled for MRM were enrolled and randomly assigned into 2 groups (30 in each) to receive a preoperative US Pecs block with 30 mL of 0.25% bupivacaine only (group 1, bupivacaine group [GB]) or 30 mL of 0.25% bupivacaine plus 1 µg/kg dexmedetomidine (group II, dexmedetomidine group [GD]). The patients were followed-up 48 hours postoperatively for vital signs (heart rate [HR], noninvasive blood pressure [NIBP], respiratory rate [RR], and oxygen saturation [Sao2]), visual analog scale (VAS) scores, time to first request of rescue analgesia, total morphine consumption, and side effects. Serum levels of cortisol and prolactin were assessed at baseline and at 1 and 24 hours postoperatively. RESULTS: A significant reduction in the intraoperative HR, systolic blood pressure (SBP), and diastolic blood pressure (DBP) starting at 30 minutes until 120 minutes in the GD group compared to the GB group (P < 0.05) was observed. The VAS scores showed a statistically significant reduction in the GD group compared to the GB group, which started immediately up until 12 hours postoperatively (P < 0.05). There was a delayed time to first request of analgesia in the GD group (25.4 ± 16.4 hrs) compared to the GB group (17 ± 12 hrs) (P = 0.029), and there was a significant decrease of the total amount of morphine consumption in the GD group (9 + 3.6 mg) compared to the GB group (12 + 3.6 mg) (P = 0.001). There was a significant reduction in the mean serum cortisol and prolactin levels at 1 and 24 hours postoperative in the GD patients compared to the GB patients (P < 0.05). LIMITATIONS: This study was limited by its sample size. CONCLUSION: The addition of 1 µg/kg dexmedetomidine to an US-modified Pecs block has superior analgesia and more attenuation to stress hormone levels without serious side effects, compared to a regular Pecs block in patients who underwent MRM. KEY WORDS: Postoperative pain, dexmedetomidine, Pecs block, stress response, breast surgery.