en Surgery Surgery Original Article Original Article <span style="font-size:12pt"><span style="line-height:14pt"><span new="" roman="" style="font-family:" times=""><b><i><span style="font-size:10.0pt"><span style="color:blue">Background</span></span></i></b><i><span style="font-size:10.0pt"><span style="color:blue">:</span></span></i><span style="font-size:10.0pt"> Brain injury is one of the complications of open heart surgery. Glutamate plays a key role in this process. In this study, we evaluated the neuroprotective effect of memantine as NMDAR inhibitor in patients undergoing on-pump coronary artery bypass graft surgery (CABG).</span><span style="font-size:9.0pt"></span></span></span></span><br> <span style="font-size:12pt"><span style="line-height:14pt"><span new="" roman="" style="font-family:" times=""><b><i><span style="font-size:10.0pt"><span style="color:blue">Methods</span></span></i></b><i><span style="font-size:10.0pt"><span style="color:blue">:</span></span></i> <span style="font-size:10.0pt">From July 2019 to May 2020, thirty-four consecutive patients selected for elective isolated on-pump coronary artery bypass graft surgery (CABG) enrolled in the trial. Patients were randomly assigned into two groups; memantine and the control group. For the memantine group, 10 mg of memantine twice daily was administered at least 72 h before surgery. Venous blood samples were collected before surgery (T1), at the end of cardiopulmonary bypass (CPB) (T2), 6h and 24h after CPB (T3 and T4). Serum concentration of S100-B was measured by enzyme-linked immunosorbent assay (ELISA) technique.</span><i><span style="font-size:10.0pt"></span></i></span></span></span><br> <span style="font-size:12pt"><span style="line-height:14pt"><span new="" roman="" style="font-family:" times=""><b><i><span style="font-size:10.0pt"><span style="color:blue">Results</span></span></i></b><i><span style="font-size:10.0pt"><span style="color:blue">:</span></span></i> <span style="font-size:10.0pt">Serum S100-B increased during CPB with a peak plasma concentration at the termination of CPB. Then it gradually decreased during the first 24 hours in both groups (<i>P</i>=0.001). The mean S100-B levels were significantly lower in the memantine group compared to the control group at the termination of CPB (0.863&plusmn;0.203 </span><span lang="EL" style="font-size:10.0pt">&mu;</span><span lang="EN-GB" style="font-size:10.0pt">g/l</span><span style="font-size:10.0pt"> vs 1.117&plusmn;0.304 </span><span lang="EL" style="font-size:10.0pt">&mu;</span><span lang="EN-GB" style="font-size:10.0pt">g/l</span><span style="font-size:10.0pt">), at 6 hours post-CPB (0.731&plusmn;0.168 </span><span lang="EL" style="font-size:10.0pt">&mu;</span><span lang="EN-GB" style="font-size:10.0pt">g</span><span style="font-size:10.0pt">/l vs 0.938&plusmn;0.206 </span><span lang="EL" style="font-size:10.0pt">&mu;</span><span lang="EN-GB" style="font-size:10.0pt">g/l</span><span style="font-size:10.0pt">), and 24 hours post-CPB (0.595&plusmn;0.189 </span><span lang="EL" style="font-size:10.0pt">&mu;</span><span lang="EN-GB" style="font-size:10.0pt">g/l</span><span style="font-size:10.0pt"> vs 0.852&plusmn;0.227 </span><span lang="EL" style="font-size:10.0pt">&mu;</span><span lang="EN-GB" style="font-size:10.0pt">g/l</span><span style="font-size:10.0pt">), respectively (<i>P</i>=0.023). The mean level of serum S100-B in memantine group was about 0.19 </span><span lang="EL" style="font-size:10.0pt">&mu;</span><span lang="EN-GB" style="font-size:10.0pt">g/l</span><span style="font-size:10.0pt"> less than the control group during the study (CI, 0.07 to 0.30; <i>P</i>=0.001). One (6.2%) patient in the control group had post-operative left arm paresthesia</span><i><span style="font-size:10.0pt"></span></i></span></span></span><br> <span style="font-size:12pt"><span style="line-height:14pt"><span new="" roman="" style="font-family:" times=""><b><i><span style="font-size:10.0pt"><span style="color:blue">Conclusion</span></span></i></b><i><span style="font-size:10.0pt"><span style="color:blue">:</span></span></i> <span style="font-size:10.0pt">Administration of memantine before on-pump CABG can attenuate the post-operative concentrations of serum S100-B, which may reduce cerebral damage during surgery.</span><b><i><span style="font-size:10.0pt"><span style="color:#0033cc"></span></span></i></b></span></span></span> serum S100-B, memantine, cardiopulmonary bypass, coronary artery bypass surgery 412 417 http://caspjim.com/browse.php?a_code=A-10-911-8&slc_lang=en&sid=1 Shervin Ziabakhsh Tabary shervin.zia@gmail.com 100319475328460036310 100319475328460036310 No Department of Cardiac Surgery, Cardiovascular Research Center Mazandaran University of Medical Sciences, Sari, Iran Parham Ziabakhsh Tabary 100319475328460036311 100319475328460036311 No Alireza Sanei Motlagh alireza.scts@yaho.com 100319475328460036312 100319475328460036312 Yes Mazandaran University of Medical Sciences, Sari, Iran