Tıp Fakültesi / Faculty of Medicine
Permanent URI for this collectionhttps://hdl.handle.net/11727/1403
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Item Evaluation of Machine Learning Algorithms for Renin-Angiotensin-Aldosterone System Inhibitors Associated Renal Adverse Event Prediction(2023) Guven, Alper Tuna; Ozdede, Murat; Sener, Yusuf Ziya; Yildirim, Ali Osman; Altintop, Sabri Engin; Yesilyurt, Berkay; Uyaroglu, Oguz Abdullah; Tanriover, Mine Durusu; 0000-0002-6310-4240; 37217407Background: Renin-angiotensin-aldosterone system inhibitors (RAASi) are commonly used medications. Renal adverse events associated with RAASi are hyperkalemia and acute kidney injury. We aimed to evaluate the performance of machine learning (ML) algorithms in order to define event associated features and predict RAASi associated renal adverse events.Materials and Methods: Data of patients recruited from five internal medicine and cardiology outpatient clinics were evaluated retrospectively. Clinical, laboratory, and medication data were acquired via electronic medical records. Dataset balancing and feature selection for machine learning algorithms were performed. Random forest (RF), k-nearest neighbor (kNN), naive Bayes (NB), extreme gradient boosting (xGB), support vector machine (SVM), neural network (NN), and logistic regression (LR) were used to create a prediction model.Results: 409 patients were included, and 50 renal adverse events occurred. The most important features predicting the renal adverse events were the index K and glucose levels, as well as having uncontrolled diabetes mellitus. Thiazides reduced RAASi associated hyperkalemia. kNN, RF, xGB and NN algorithms have the highest and similar AUC (> 98%), recall (> 94%), specifity (> 97%), precision (> 92%), accuracy (> 96%) and F1 statistics (> 94%) performance metrics for prediction.Conclusion: RAASi associated renal adverse events can be predicted prior to medication initiation by machine learning algorithms. Further prospective studies with large patient numbers are needed to create scoring systems as well as for their validation.Item The Incidence and Risk Factors of Acute Kidney Injury After Left Ventricular Assist Device Implantation(2023) Atar, Funda; Sahinturk, Helin; Zeyneloglu, Pinar; Ozdemirkan, Aycan; 0000-0003-0159-4771; AAJ-1419-2021Objective: Left ventricular assist device surgery (LVAD) associated acute kidney injury (AKI) is a severe complication of cardiac surgery with 15-45% incidence. The study evaluated AKI in the early postoperative period after LVAD surgery using the Kidney Disease: Improving Global Outcomes (KDIGO) criteria and compare patients with and without AKI to determine the incidence, risk factors, and clinical outcomes. Materials and Methods: In this retrospective cohort study, the medical records of all patients aged between 18 and 75 years who underwent LVAD implantation from January 2011 to December 2016 were reviewed. Patients were divided into two groups based on the development of AKI to analyze demographic features and perioperative variables. AKI was defined according to the KDIGO criteria. Results: Out of 57 patients, 10 (18%) were female, and the cohort's mean age was 44.6 +/- 16.1 years. Thirty-six patients (63%) developed AKI following LVAD implantation. Logistic regression analysis revealed the duration of cardiopulmonary bypass (CPB), mean arterial pressure, and cumulative fluid balance on the first postoperative day as independent risk factors for AKI [odds ratio (OR): 1.013, confidence interval (CI) 95% 1.000-1.025, p=0.05; OR: 0.929, CI 95% 0.873-0.989, p=0.02; OR: 1.001, CI 95% 1.000-1.001, p=0.04 respectively]. Hospital mortality (58% vs. 24%, p=0.01) and 30-day mortality (39% vs. 5%, p=0.01) were significantly higher in patients who had AKI. Conclusion: Risk factors for the occurrence of AKI include a longer duration of CPB, lower mean arterial pressures, and higher cumulative fluid balance on the first postoperative day. Therefore, AKI is one of the most important causes of morbidity and mortality after LVAD.Item Serum Interleukin-18 As an Early Marker of Acute Kidney Injury Following Open Heart Surgery(2014) Unal, Ertekin Utku; Ozen, Anil; Boysan, Emre; Tak, Sercan; Basar, Veysel; Turkcan, Basak Soran; Durukan, Elif; Tutun, Ufuk; Birincioglu, Cemal Levent; https://orcid.org/0000-0002-8579-5564; AAJ-8621-2021Background: This study aims to investigate whether serum interleukin (IL)-18 is an early biomarker of acute kidney injury (AKI). Methods: Thirty consecutive patients (22 males, 8 females; mean age 62.4 +/- 9.0 years; range 49 to 78 years) who underwent open-heart surgery were enrolled in this prospective study. Serum IL-18 concentrations were analyzed prior to induction of anesthesia, at weaning from cardiopulmonary bypass (CPB) and two hours after weaning from CPB. Serum creatinine levels were analyzed in the postoperative first, second, and third days. Acute kidney injury was defined as creatinine levels exceeding 50% of the basal value or exceeding the basal value by 0.3 mg/dl at 48 hours postoperatively. The patients were classified into two groups including AKI (n=12) and non-AKI (n=18). Serum IL-18 levels were compared between the groups. Results: Twelve patients (40%) developed AKI. The diagnosis was able to be made using the serum creatinine levels at 24 to 48 hours postoperatively. Although IL-18 concentrations at weaning from CPB decreased slightly in the AKI group, the decrease in the non-AKI presenting group was higher. Using univariate analyses, IL-18 concentrations at two hours after weaning from CPB were found to be related to AKI (p=0.031). The difference in serum IL-18 concentrations between the preoperative period and two hours after weaning from CPB were found to be statistically significant (p=0.017). According to the Receiver operating characteristic curve analysis, the threshold value for AKI prediction of serum IL-18 concentrations at two hours after weaning from CPB was 353.7 pg/ml with a sensitivity of 58.3% and a specificity of 83.3% (AUC=0.736). Conclusion: Serum IL-18 concentration may be used as a biochemical indicator for early detection of acute kidney injury following open heart surgery.Item A Comparison of Two Coronary Artery Bypass Graft Surgery Techniques with Respect to Acute Kidney Injury(2015) Beyazpinar, Deniz Sarp; Gultekin, Bahadir; Kayipmaz, Afsin Emre; Kayipmaz, Cagri; Sezgin, Atilla; Giray, Tufan Akin; Kavalci, Cemil; 0000-0003-2529-2946; 0000-0003-4619-4034; AAC-2597-2020; AGG-1308-2022; ABA-7388-2021; ABA-9675-2021; AGQ-5015-2022Background: This study aims to compare the conventional coronary artery bypass graft (CABG) surgery and on-pump beating heart bypass grafting (OPBHB) with respect to acute kidney injury and subsequent dialysis requirement. Methods: Between January 2012 and October 2013, medical records of 77 patients who underwent conventional CABG and 76 patients who underwent OPBHB for coronary artery disease in our clinic were retrospectively analyzed. Results: There was no significant difference in preoperative renal function test results between the groups. However, there was a significant difference in cardiopulmonary bypass time and length of intensive care unit stay (p<0.05). Seven (9.21%) of 76 patients in OPBHB group and 11 (14.28%) of 77 patients in CABG group developed acute kidney injury; however, it did not indicate a statistically significant difference between the groups (p>0.05). One patient in OPBHB group and four patients in CABG group also needed dialysis. Conclusion: Our study results suggest that OPBHB is superior to the conventional CABG in terms of acute kidney injury and, more importantly, development of acute renal failure in patients with a serum creatinine level of 1-1.3 mg/dL.Item Incidence and Patient Outcomes in Renal Replacement Therapy After Orthotopic Liver Transplant(2017) Ayhan, Asude; Ersoy, Zeynep; Ulas, Aydin; Zeyneloglu, Pinar; Pirat, Arash; Haberal, Mehmet; 0000-0003-0767-1088; 0000-0003-3299-6706; 0000-0002-3462-7632; 0000-0003-2312-9942; 0000-0002-8130-9901; 28260481; AAF-3066-2021; AAJ-2066-2021; AAJ-8097-2021; AAJ-2057-2021; C-3736-2018Objectives: Our objective was to evaluate the incidence of renal replacement therapy after orthotopic liver transplant and to evaluate and analyze patient outcomes. Materials and Methods: We performed a retrospective analysis of 177 consecutive patients at a tertiary care unit who underwent orthotopic liver transplant between January 2010 and June 2016. Patients who were admitted to the intensive care unit after orthotopic liver transplant and who required renal replacement therapy were included. Results: A total of 177 (79 adult, 98 pediatric) orthotopic liver transplants were performed during the study period. Of these, 35 patients (19%) required renal replacement therapy during the early posttrans plantation period. After excluding 5 patients with previous chronic renal failure, 30 patients (17%; 20 adult [25%], 10 pediatric [10%]) with acute kidney injury required renal replacement therapy. The mean patient age was 31.1 +/- 20.0 years, with a mean Model for End-stage Liver Disease score of 16.7 +/- 12.3. Of the patients with acute kidney injury who underwent renal replacement therapy, in-hospital mortality was 23.3% (7 of 30 patients), and 40% remained on dialysis. No significant difference was seen in mortality between early versus delayed initiation of renal replacement therapy in patients with stage 3 acute kidney injury (P = .17). Conclusions: Of liver transplant recipients who present with acute kidney injury, 19% require renal replacement therapy, and in-hospital mortality is 20% in the early postoperative period.Item Evaluation of acute kidney injury after surgery for congenital heart disease in neonates: a tertiary hospital experience(2022) Oktener Anuk, Ezgi; Erdogan, Ilkay; Ozkan, Murat; Baskin, Esra; Varan, Birgul; Tokel, Kursad N.; 0000-0001-6887-3033; 0000-0003-3991-8479; 35382696; ABB-2220-2021Purpose of the article Acute kidney injury (AKI) after cardiac surgery in children with congenital heart disease (CHD) is a serious complication closely associated with high morbidity and mortality. Despite numerous studies on AKI in children, most studies have excluded neonates. We sought to characterize AKI associated with cardiac surgery in neonates, determine its incidence, perioperative and postoperative risk factors, and short-term results. Materials and methods This retrospective study included 177 neonates who were operated on for CHD in our hospital between January 2015 and December 2019. Data of the patients were analyzed according to nKDIGO (neonatal Kidney Disease Improving Global Outcomes) and nRIFLE (neonatal Risk, Injury, Failure, Loss of function, End-stage kidney disease) criteria for evaluating AKI retrospectively. Data of groups with and without AKI were analyzed. Results The average age of 177 neonates were 8.2 +/- 6.1 (1-28) days. Twenty-two (12.4%) neonates had CS-AKI defined according to nKDIGO criteria. Four (2.3%) neonates reached nKDIGO stage I, 1 (0.6%) reached stage II, 17 (9.6%) reached stage III. Thirty-eight (21.5%) neonates had CS-AKI defined according to nRIFLE criteria. Twenty-four (13.6%) neonates reached nRIFLE stage risk(R), 6 (3.4%) reached stage injury(I), 8 (4.5%) reached stage failure (F). The incidence of cardiac surgery-associated acute kidney injury (CS-AKI) in neonates was 12.5% and 21.5% for nKDIGO and nRIFLE, respectively. The percentage difference between nKDIGO and nRIFLE for AKI assessment was due to the criteria for nRIFLE stage risk(R) urine output < 1.5 mL/kg/h for 24 h. In both classifications, the duration of cardiopulmonary bypass, operation, inotropic treatment, and mechanical ventilation, length of intensive care unit (ICU), and hospital stay were significantly higher in the AKI group than those without AKI group (p<.05). The mortality rate in the groups with AKI was found to be significantly higher (p<.05) than in the groups without AKI. In Kappa analysis, when two classifications were compared according to AKI stages, a significant agreement was found between nKDIGO and nRIFLE classifications (p<.05) (Kappa: 0.299). Conclusion AKI and mortality rates were similar between groups according to the nKDIGO and nRIFLE criteria. For early prediction of AKI and adverse outcomes, diagnostic reference intervals might be specified in more detail in neonates undergoing cardiac surgery for CHD.Item A model for acute kidney injury in severe burn patients(2022) Karakaya, Emre; Akdur, Aydincan; Aydogan, Cem; Turk, Emin; Sayin, Cihat Burak; Soy, Ebru Ayvazoglu; Yucebas, Sait Can; Alshalabi, Omar; Haberal, Mehmet; 0000-0002-4879-7974; 0000-0002-8726-3369; 0000-0002-8726-3369; 0000-0002-0993-9917; 0000-0002-3462-7632; 33879373; AAD-5466-2021; AAA-3068-2021; AAA-3068-2021; AAC-5566-2019; AAJ-8097-2021Introduction: In patients with severe burns, morbidity and mortality are high. One factor related to poor prognosis is acute kidney injury. According to the AKIN criteria, acute kidney injury has 3 stages based on urine output, serum creatinine level, and renal replacement therapy. In this study, we aimed to create a decision tree for estimating risk of acute kidney injury in patients with severe burn injuries. Methods: We retrospectively evaluated 437 adult patients with >20% total burn surface area injury who were treated at the Baskent University Ankara and Konya Burn Centers from January 2000 to March 2020. Patients who had high-voltage burn and previous history of kidney disease were excluded. Patient demographics, medical history, mechanism of injury, presence of inhalation injury, depth of burn, laboratory values, presence of oliguria, need for renal replacement therapy, central venous pressure, and prognosis were evaluated. These data were used in a "decision tree method" to create the Baskent University model to estimate risk of acute kidney injury in severe burn patients. Results: Our model provided an accuracy of 71.09% for risk estimation. Of 172 patients, 78 (45%) had different degrees of acute kidney injury, with 26 of these (15.1%) receiving renal replacement therapy. Our model showed that total burn surface area was the most important factor for estimation of acute kidney injury occurrence. Other important factors included serum creatinine value, burn injury severity score, hemoglobin value, neutrophil-tolymphocyte ratio, and platelet count. Conclusion: The Baskent University model for acute kidney injury may be helpful to determine risk of acute kidney injury in burn patients. This determination would allow appropriate treatment to be given to high-risk patients in the early period, reducing the incidence of acute kidney injury. (c) 2021 Published by Elsevier Ltd.Item Effect of acute kidney injury on long-term mortality in patients with ST-segment elevation myocardial infarction complicated by cardiogenic shock who underwent primary percutaneous coronary intervention in a high-volume tertiary center(2020) Hayiroglu, Mert Ilker; Bozbeyoglu, Emrah; Yildirimturk, Ozlem; Tekkesin, Ahmet Ilker; Pehlivanoglu, Seckin; 31974325Objective: Acute kidney injury (AKI) is a reflection of both renal and cardiac reserve in patients with ST-segment elevation myocardial infarction (STEMI), but there is a lack of evidence related to the effect of AKI on long-term mortality in patients with STEMI. This study was an investigation of the prognostic value of AKI for long-term mortality in patients with STEMI complicated by cardiogenic shock (CS) and primary percutaneous coronary intervention (PPCI). Methods: This retrospective analysis evaluated the long-term prognostic impact of AKI on 492 patients with STEMI complicated by CS who were treated with PPCI. AKI was defined as >= 0.3mg/dL increase in serum creatinine within 48 hours or a >= 50% increase in serum creatinine in 7 days, or a reduction in urine output (documented oliguria of less than 0.5mL/kg per hour >6 hours. Patients were grouped according to the incidence of AKI and long-term mortality was compared. Cox regression analysis was used to determine independent prognostic factors of long-term mortality. Results: In Cox regression analysis, the age- and sex- adjusted hazard ratios (HRs) were higher for all-cause mortality in patients with AKI. [HR: 4.556; 95% confidence interval: (CI) 2.370-8.759]. After adjustment for confounding variables, the relative risk was greater for patients with AKI in comparison with patients without AKI (HR: 2.207; 95% CI: 1.150-4.739). Age (HR: 1.060, 95% CI: 1.027-1.094; p<0.001), left ventricular ejection fraction (HR: 0.952, 95% CI: 0.916-0.989; p=0.012), blood urea nitrogen level (HR: 1.019, 95% CI: 1.005-1.034; p=0.010), and AKI (HR: 2.244, 95% CI: 1.077-4.676; p=0.031) were found to be independent factors to determine long-term mortality. Conclusion: The results of this study demonstrated that AKI was an independent prognostic factor for long-term mortality among patients with STEMI complicated by CS and treated with PPCI.Item Urinay neutrophil gelatinase-associated lipocalin as a biomarker in different renal problem(2020) Turgut, Didem; Piskinpasa, Serhan Vahit; Yenigun, Ezgi Coskun; Aydemir, Nihal; Dede, Fatih; 0000-0001-7474-5927; 32927927; AAI-9418-2021Background/aim: Neutrophil gelatinase-associated lipocalin (NGAL) is used previously to estimate the etiology, severity, and clinical outcomes of acute kidney injury (AKI). However, the role of urinary NGAL (uNGAL) in the postrenal setting is not clear. In our study, we aimed to discover the cut-off value of uNGAL that can be used in the differential diagnosis of underlying AKI etiologies. Materials and methods: In this prospective cross-sectional study, we examined 82 subjects in four groups: patients that had (1) postrenal AKI; (2) AKI other than postrenal etiologies; (3) stable chronic kidney disease; and (4) healthy subjects. A renal function assessment was carried out by measuring serum creatininc (sCr) and uNGAL at the time of diagnosis [0th min (T0)]. We followed the study group for three months. Results: At the time of diagnosis, sCr (T0) was highest in the postrenal AKI and AKI groups in contrast to stable chronic kidney disease patients and healthy subjects (P < 0.001), as expected. T0 median uNGAL was highest in the postrenal group (P < 0.001). Area under curve (AUC) of uNGAL to estimate postrenal AKI presence was 0.957 (95% CI, 0.897-1.000; P < 0.001). The cut-off point of uNGAL was 42.625 ng/mL for this estimation. Conclusion: Patients with AKI must be classified according to the underlying etiologies as soon as possible. uNGAL may be useful to estimate the etiologies, and whether the problem is acute or chronic in the course. In postrenal kidney problems, to plan the urgency of the urologic procedures, it is crucial.Item Iloprost as an acute kidney injury-triggering agent in severely atherosclerotic patients(2016) Uyar, Mehtap Erkmen; Yucel, Piril; Ilin, Sena; Bal, Zeynep; Yildirim, Saliha; Uyar, Ahmet Senol; Akay, Tankut; Tutal, Emre; Sezer, Siren; 27841898; AAZ-5795-2021Background: Iloprost, a stable prostacyclin analog, is used as a rescue therapy for severe peripheral arterial disease (PAD). It has systemic vasodilatory and anti-aggregant effects, with severe vasodilatation potentially causing organ ischaemia when severe atherosclerosis is the underlying cause. In this study, we retrospectively analysed renal outcomes after iloprost infusion therapy in 86 patients. Methods: Eighty-six patients with PAD who received iloprost infusion therapy were retrospectively analysed. Clinical and biochemical parameters were recorded before (initial, Cr1), during (third day, Cr2), and after (14th day following the termination of infusion therapy, Cr3) treatment. Acute kidney injury (AKI) was defined according to KDIGO guidelines as a >= 0.3 mg/dl (26.52 mu mol/l) increase in creatinine levels from baseline within 48 hours. Results: Cr2 (1.46 +/- 0.1 mg/dl) (129.06 +/- 8.84 mu mol/l) and Cr3 (1.53 +/- 0.12 mg/dl) (135.25 +/- 10.61 mu mol/l) creatinine levels were significantly higher compared to the initial value (1.15 +/- 0.6 mg/dl) (101.66 +/- 53.04 mu mol/l). AKI was observed in 36 patients (41.86%) on the third day of iloprost infusion. Logistic regression analysis revealed smoking and not using acetylsalicylic acid as primary predictors (p = 0.02 and p = 0.008, respectively) of AKI during iloprost treatment. On the third infusion day, patients' urinary output significantly increased (1813.30 +/- 1123.46 vs 1545.17 +/- 873.00 cm(3)) and diastolic blood pressure significantly decreased (70.07 +/- 15.50 vs 74.14 +/- 9.42 mmHg) from their initial values. Conclusion: While iloprost treatment is effective in patients with PAD who are not suitable for surgery, severe systemic vasodilatation can cause renal ischaemia, resulting in non-oliguric AKI. Smoking, no acetylsalicylic acid use, and lower diastolic blood pressure are the clinical risk factors for AKI during iloprost treatment.