1860 Bali Medical Journal 2022; 11(3): 1860-1864 | doi: 10.15562/bmj.v11i3.3847 ORIGINAL ARTICLE ABSTRACT Correlation of S100B level and postoperative cognitive dysfunction (POCD) events among patients with ear, nose and throat (ENT) surgeries with controlled hypotension Boby Abdul Rahman 1 , Prananda Surya Airlangga 1* , Andy Nauman Saputra 1 , Prihatma Kriswidyatomo 1 , Agustina Salinding 1 , Hamzah 1 , Maulydia 1 , Muhtarum Yusuf 2 Introduction: Controlled hypotension is one of the techniques applied to several microscopic ear, nose, and throat (ENT) surgeries. However, this technique has risks and complications, which result in impaired perfusion and oxygenation of organs including the brain that could trigger the postoperative cognitive dysfunction (POCD). Damage that occurs in brain cells can trigger the secretion of biomarker proteins in the blood, one of which is S100B which can indicate nerve damage in the intra and postoperative period. This study aimed to analyze the correlation between S100B protein level and the incidence of POCD in patients who received ENT surgeries with controlled hypotension. Methods: A cross-sectional study was conducted among patients that underwent elective ENT surgeries at Dr. Soetomo General Academic Hospital, Surabaya, from July to August 2022. Cognitive function was assessed using Mini-mental State Examination (MMSE) at 12 hours before and 2 and 24 hours after surgery. The level of S100B was measured using enzyme- linked immunosorbent assay (ELISA) 12 hours prior surgery and 30 minutes post-surgery. Results: A total of 31 patients were recruited in the study, including a mean age of 31.7 years. The mean S100B levels in POCD patients pre- and postoperative were 311.97 ng/L, and 415.34 ng/L, respectively. In non-POCD patients, the mean levels of S100B pre and postoperative were 436.90 ng/L, and 444.29 ng/L, respectively. There were 3 (9.7%) patients experienced POCD. Our data suggested there was a signifcant diference between preoperative and postoperative S100B levels in the groups of patients with POCD (103.37ng/L) and non-POCD (7.38 ng/L) (p<0.001). Patients that experienced POCD had signifcantly increased S100B compared to those who did not. Conclusion: There is a correlation between changes of S100B levels and the incidence of POCD in patients undergoing ENT surgeries with controlled hypotension. Keywords: S100B level, postoperative cognitive dysfunction, controlled hypotension, mini-mental state examination, POCD. Cite This Article: Rahman, B.A., Airlangga, P.S., Saputra, A.N., Kriswidyatomo, P., Salinding, A., Hamzah., Maulydia., Yusuf, M. 2022. Correlation of S100B level and postoperative cognitive dysfunction (POCD) events among patients with ear, nose and throat (ENT) surgeries with controlled hypotension. Bali Medical Journal 11(3): 1860-1864. DOI: 10.15562/bmj.v11i3.3847 1 Department of Anesthesiology and Reanimation, Faculty of Medicine, Universitas Airlangga - Dr Soetomo General Academic Hospital, Surabaya, 60132, Indonesia; 2 Department of Otorhinolaryngology, Head and Neck Surgery, Faculty of Medicine, Universitas Airlangga - Dr Soetomo General Academic Hospital, Surabaya, 60132, Indonesia; *Corresponding author: Prananda Surya Airlangga; Department of Anesthesiology and Reanimation, Faculty of Medicine, Universitas Airlangga, Surabaya, 60132, Indonesia; prananda-s-a@fk.unair.ac.id Received: 2022-10-09 Accepted: 2022-11-11 Published: 2022-12-01 1860 Bali Medical Journal (Bali MedJ) 2022, Volume 11, Number 3: 1860-1864 P-ISSN.2089-1180, E-ISSN: 2302-2914 Open access: www.balimedicaljournal.org INTRODUCTION Controlled hypotension is one of the techniques applied in microscopic ear, nose and throat (ENT) surgeries to minimize the amount of bleeding, increase visualization of the operating feld, shorten the duration of the operation, and reduce the risk of complications. 1 It was conducted by lowering systolic blood pressure to the range of 80-90 mmHg with mean arterial pressure (MAP) 50-65 mmHg, or reduce the MAP 20-30% from baseline. 2 However, the controlled hypotension technique has its own risks or complications that may occur to the patients. 3 Low blood pressure could result in impaired organ perfusion and oxygenation due to decreased blood fow to vital organs such as the heart, brain, kidneys, and splanchnic. 2 In brain, this condition could trigger postoperative cognitive dysfunction (POCD). 4 POCD is a functional mental disorder afecting cognitive processes such as verbal memory, visual memory, impaired concentration, attention, and language comprehension. In general, cases of POCD occur in geriatric patient of which 30% of postoperative geriatric patients experience POCD in the frst one week. 5 As many as 30–80% of these POCD events occur in the frst week and 10–60% occur 3–6 months afer surgery. 6 Te incidence of POCD in ENT surgeries with controlled hypotension was 13.3% in the frst one hour and 6.6% at 24 hours postoperatively. 7 Mini-Mental State Examination (MMSE) is one of the most common tool used to diagnose the incidence of POCD. 8 Neuroinfammation, cerebral hypoperfusion, ischemia and apoptosis of brain cells are the pathophysiological mechanisms associated with POCD. 9 Damage that are occurred in brain cells could trigger the secretion of several biomarker proteins in the blood including S100B, neuron-specifc enolase (NSE), glial fbrillary acidic protein (GFAP), and Tau protein. 10,11 S100B protein is one of