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Dive into the research topics where Hasan Karabulut is active.

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Featured researches published by Hasan Karabulut.


Perfusion | 2004

Highly positive intraoperative fluid balance during cardiac surgery is associated with adverse outcome.

Fevzi Toraman; Serdar Evrenkaya; Murat Yuce; Onur Turek; Nazan Aksoy; Hasan Karabulut; Önder Demirhisar; Cem Alhan

Hemodilution and increase in capillary permeability occurring with cardiopulmonary bypass (CPB) impose a risk for tissue edema and blood transfusion that may result in an increased complication rate after coronary artery bypass grafting (CABG). Of the 1280 consecutive patients undergoing isolated on-pump CABG, total fluid balance at the end of the operation was less than or equal to 500 mL in 1155 (Group 1) and more than 500 mL in 125 (Group 2). During CPB, blood was added to the reservoir only when the hematocrit fell to 17% or less and crystalloid solution only when the pump flow index fell below 2.0 L/min/m2. Anesthetic, surgical, and postoperative management and diagnoses were the same in all patients, and a single surgical and anesthesia team performed all operations. No patient was excluded from the study. Results: Hypertension, diabetes, chronic obstructive pulmonary disease, New York Heart Association (NYHA) Class III - IV, use of angiotensin converting enzyme (ACE) inhibitors, chronic renal failure, and female gender were the significant preoperative risk factors for increased volume replacement during CPB. The groups were similar in body mass index, preoperative hematocrit values, total fluid balance in the intensive care unit (ICU), and total chest tube output. However, red blood cells’ transfusion rate, readmission rate to the ICU and length of hospital stay were significantly higher in Group 2 patients. Multiple logistic regression revealed that age < 70 years (p < 0.001, Odds Ratio (OR): 2, 95% CI: 1.4 - 2.8), and total fluid balance > 500 mL at the end of the operation (p < 0.01, OR: 2.2, 95% CI: 1.5-3.2) were the predictors of increased length of stay. For transfusion of red blood cells, age > 70 years (p < 0.0001, OR: 2.3, 95% CI: 1.6-3.3), and total fluid balance > 500 mL at the end of the operation (p < 0.001, OR: 2, 95% CI: 1.3-2.9) were the only significant risk factors. This study suggests that intraoperative volume overload increases blood transfusion and length of hospital stay in patients undergoing CABG.


Heart Surgery Forum | 2004

Lactic acidosis after cardiac surgery is associated with adverse outcome.

Fevzi Toraman; Serdar Evrenkaya; Murat Yuce; Nazan Aksoy; Hasan Karabulut; Yildirim Bozkulak; Cem Alhan

BACKGROUND The accurate identification of patients who have the potential to further deteriorate after cardiac surgery is difficult. Elevated serum lactate level after cardiac surgery is an indicator of systemic hypoperfusion and tissue hypoxia. The aim of this study was to investigate the effect of increased serum lactate on outcome after on-pump coronary artery bypass grafting. METHODS Serum lactate level was measured in 776 patients within half an hour after surgery. Lactate level was less than or equal to 2 mmol/L in 534 patients (low lactate group) and more than 2 mmol/L in 242 patients (high lactate group). Continuous variables were analyzed with the Student t test. The chi 2 test and Fisher exact test were used to compare categorical variables. RESULTS Demographic characteristics and details of surgery were similar in both groups. Increased cross-clamp and cardiopulmonary bypass times and highly positive fluid balance at the end of surgery were associated with a significant rise in postoperative lactate levels, which leads to increased need for intraaortic balloon pump support (odds ration [OR], 5.9, P =.006), increased likelihood of >24 h intensive care unit stay (OR, 3.4, P =.0001), greater need for red blood cell transfusion (OR, 1.6, P =.002), increased length of hospital stay, and higher mortality rates (OR, 5.6, P =.04). CONCLUSIONS This study has demonstrated that elevated blood lactate level is associated with adverse outcome, and monitoring the blood lactate level during and after cardiac surgery is a valuable tool in identifying the patients who have the potential to deteriorate.


Cardiovascular Surgery | 2003

EuroSCORE overestimates the cardiac operative risk.

Hasan Karabulut; F. Toraman; C. Alhan; G. Çamur; S. Evrenkaya; S. Dağdelen; S. Tarcan

INTRODUCTION It was the purpose of our study to assess the validity of EuroSCORE (European system for cardiac operative risk evaluation) in our patient population. MATERIALS AND METHODS Between March 1999 and August 2001, information on risk factors and mortality was collected for 1123 consecutive adult patients undergoing heart surgery with cardiopulmonary bypass. EuroSCORE was used for risk stratification. Mean age +/- standard deviation was 58.6 +/- 10.9 and 29.1% of the patients were female. The area under the receiver operating characteristic (ROC) curve was calculated as an index for the predictive value of the scoring system. RESULTS The area under the ROC curve was 0.824 for all patients and 0.828 for the isolated CABG subgroup which shows an excellent predictive ability. When the scoring system was applied in low, medium, and high risk groups, there was no overlap between 95% confidence intervals of observed and expected mortality in all three groups both for the isolated CABG cases and for all patients. Decreased left ventricular ejection fraction, emergent operation, and preoperative unstable angina requiring i.v. nitrate treatment were significant predictive variables for early mortality. CONCLUSION EuroSCORE is a simple and objective system for predicting the risk of heart surgery. The predictive power of the EuroSCORE is excellent, however it seems that mortality is considerably overestimated by this score.


The Annals of Thoracic Surgery | 1996

Intermittent aortic cross-clamping and cold crystalloid cardioplegia for low-risk coronary patients

H. Cem Alhan; Hasan Karabulut; Remzi Tosun; Fehime Karakoç; Imer Okar; Erdoğan Demiray; Sümer Tarcan; Besim Yiğiter

BACKGROUND Blood cardioplegic strategies have been shown to increase myocardial oxygen uptake, replenish depleted energy stores, and improve myocardial function and survival in the high-risk subset of patients. However, the superiority of these techniques over intermittent aortic cross-clamping and crystalloid cardioplegia in low-risk patients is still controversial. METHODS This study consisted of two parts. In the first part, we assessed the results of a recent cohort of 399 consecutive low-risk patients undergoing their first coronary artery bypass grafting between 1993 and 1995 using cold crystalloid cardioplegia (n = 128) and intermittent aortic cross-clamping (n = 271). In the second part of the study, 40 consecutive low-risk patients undergoing elective first time coronary artery bypass grafting were randomly divided into two equal groups. One group received cold crystalloid cardioplegia and the other group had myocardial management with intermittent aortic cross-clamping. The two groups were compared with respect to hemodynamic, biochemical and ultrastructural changes. RESULTS The overall mortality rate, the perioperative myocardial in the need for intraaortic balloon pumps, and the need for inotropic agents were 0.25%, 1.5%, 1%, and 5.8%, respectively. No significant differences were observed between the groups with respect to these clinically defined end points. CONCLUSIONS Both intermittent aortic cross-clamping and cold crystalloid cardioplegia techniques may be used safely in low-risk patients undergoing first-time coronary artery bypass grafting.


Interactive Cardiovascular and Thoracic Surgery | 2008

The impact of allogenic red cell transfusion and coated bypass circuit on the inflammatory response during cardiopulmonary bypass: a randomized study

Sahin Senay; Fevzi Toraman; Serdar Gunaydin; Meltem Kilercik; Hasan Karabulut; Cem Alhan

OBJECTIVES This study is designed to determine and compare the effects of transfusion and coated circuits on the inflammatory response during cardiopulmonary bypass. METHODS Forty patients were randomized into two groups according to the type of extracorporeal circuit used and later prospectively enrolled into two subgroups according to the need for red cell transfusion during CPB (leading to 4 groups--10 patients per group; group 1: with no transfusion and standard oxygenator, group 2: with transfusion and standard oxygenator, group 3: with no transfusion and coated oxygenator, group 4: with transfusion and coated oxygenator). Serum lactate, interleukin 6, human tumor necrosis factor alpha (TNF-alpha), D-dimer and CRP levels were measured at three time points (T1: start of CPB, T2: before removal of aortic cross-clamp, T3: 45 min after the completion of proximal anastomoses). Protein adsorption of oxygenator fibers was measured. Outcome parameters were recorded. RESULTS Interleukin 6, TNF-alpha, D-dimer and lactate levels increased at T2 and T3 in all groups (P<0.05 within groups). The increase in interleukin 6 was significant at T2 in group 2 when compared to group 1 (8.0+/-3.9 vs. 4.4+/-1.8, P=0.03). The increase in TNF-alpha was higher at T2 in group 1 when compared to group 3 (16.0+/-4.2 vs. 11.7+/-2.8, P=0.05) and in group 2 when compared to group 3 at T2 and T3 (15.3+/-4.6 vs. 11.7+/-2.8, P=0.06; 17.6+/-5.0 vs. 13.7+/-3.9, P=0.06). Protein adsorption was higher in group 1 and group 2 (group 1 vs. group 3, 2.2+/-0.8 vs. 1.4+/-0.3, P=0.01; group 2 vs. group 3, 2.4+/-0.7 vs. 1.4+/-0.3, P=0.02; group 2 vs. group 4, 2.4+/-0.7 vs. 1.8+/-0.3, P=0.04), it was also higher at group 4 when compared to group 3 (1.8+/-0.3 vs. 1.4+/-0.3, P=0.03). CONCLUSIONS Allogenic red cell transfusion enhances inflammatory response during CPB; coated circuit systems have a limiting effect on this inflammatory reaction.


Heart Surgery Forum | 2010

Readmission to the intensive care unit after fast-track cardiac surgery: an analysis of risk factors and outcome according to the type of operation.

Fevzi Toraman; Sahin Senay; Ümit Güllü; Hasan Karabulut; Cem Alhan

INTRODUCTION In the present study, we investigated risk factors for intensive care unit (ICU) readmission after fasttrack cardiac surgery and analyzed outcome data according to the type of surgical procedure. METHODS Between 1999 and 2008, we prospectively enrolled 4270 consecutive patients who underwent isolated coronary artery bypass grafting (CABG) (CABG group, n = 3754), isolated valve surgery (valve group, n = 353), or combined CABG and valve surgery (CABG + valve group, n = 163) in the study. RESULTS Ninety-eight patients (2.2%) were readmitted to the ICU. Of these patients, 73 were in the CABG group (1.9% of this group), 16 were in the valve group (4.5%), and 9 were in the CABG + valve group (5.5%). The main reason for ICU readmission in all groups was respiratory distress. A multivariate analysis showed that the independent risk factors for ICU readmission in the CABG group were an age >65 years (odds ratio [OR], 2.9; 95% confidence interval [CI], 1.5-5.4; P = .001), peripheral arterial disease (OR, 2.7; 95% CI, 1.2-6.1; P = .016), and drainage >500 mL (OR, 2.5; 95% CI, 1.2-5.1; P = .009). The independent risk factors for the valve group included only preoperative congestive heart failure (OR, 3.9; 95% CI, 1.3-11.7; P = .01). No independent risk factor was defined for the CABG + valve group. Mortality was significantly higher among the readmitted patients in all groups. CONCLUSIONS The risk factors for readmission after cardiac surgery with fast-track recovery may differ according to the type of operation. A strict control of volume balance and blood transfusion may further help prevent the occurrence of the most frequent cause of readmission, respiratory failure.


Perfusion | 2009

Is it the patient or the physician who cannot tolerate anemia? A prospective analysis in 1854 non-transfused coronary artery surgery patients.

Sahin Senay; Fevzi Toraman; Hasan Karabulut; Cem Alhan

Background and objective: Low hematocrit level and transfusion may coexist during cardiopulmonary bypass and the actual impact of one on the outcome parameters may be counfounded or masked by the other. This study aims to determine the impact of the lowest hematocrit level during cardiopulmonary bypass on outcome parameters in non-transfused patients. Methods: Two thousand six hundred and thirty-two consecutive patients who underwent isolated coronary artery bypass graft (CABG) surgery with cardiopulmonary bypass were evaluated prospectively:1854 (70.4%) patients who did not receive any red blood cells during hospital stay were included in the study. Perioperative data and outcome parameters were recorded. Outcomes were evaluated in 2 groups according to the lowest level of hematocrit (>21%: high hematocrit group, n= 1680, (91.6%) and ≤21%: low hematocrit group, n=174, (9.4%)) during cardiopulmonary bypass. Results: Overall mean lowest hematocrit level of patients was 27.7±4.4% (19.7±1.9% in the low hematocrit group, 28.5±4.1% in the high hematocrit group). The comparison of outcome parameters regarding the time on ventilator, duration of intensive care unit stay, intensive care unit re-admission, hospital re-admission, reoperation for bleeding or tamponade, low cardiac output, postoperative atrial fibrillation, stroke, creatinine level at hospital discharge, new onset renal failure, mediastinitis, pulmonary complication and mortality rates were similar in both groups. Conclusions: Our findings suggest that a lowest hematocrit level of ≤21% during cardiopulmonary bypass has no adverse impact on outcome after isolated coronary surgery in non-transfused patients.


Asian Cardiovascular and Thoracic Annals | 2007

Adjusting Oxygen Fraction to Avoid Hyperoxemia during Cardiopulmonary Bypass

Fevzi Toraman; Serdar Evrenkaya; Sahin Senay; Hasan Karabulut; Cem Alhan

Although an adverse influence of hyperoxemia during cardiopulmonary bypass is well documented, there is a wide range of oxygen settings during cardiopulmonary bypass, based mostly on trial and error. The aim of this study was to determine the optimal inspired oxygen fraction during cardiopulmonary bypass. Ninety patients undergoing isolated coronary artery bypass operations were randomly allocated to one of 3 groups of 30 each. In group 1, cardiopulmonary bypass was started with an inspired oxygen fraction of 0.40, increased to 0.60 during rewarming. These settings were 0.40 and 0.50 in group 2, and 0.35 and 0.45 in group 3. Samples for blood gas analysis were collected at defined time periods during the operation. PaO2 was significantly higher in groups 1 and 2 compared to group 3. All patients in group 1 and 88% of patients in group 2 suffered at least one episode of hyperoxemia during cardiopulmonary bypass, compared to 30% of patients in group 3. The differences were significant, and we concluded that to avoid hyperoxemia, inspired oxygen fraction should be kept at 0.35 during cardiopulmonary bypass and increased to 0.45 during rewarming.


Asian Cardiovascular and Thoracic Annals | 2005

Comparison of Antihypertensives after Coronary Artery Surgery

Fevzi Toraman; Hasan Karabulut; Onur S. Goksel; Serdar Evrenkaya; Sümer Tarcan; Cem Alhan

Hypertension following coronary artery bypass grafting is a common problem that may result in postoperative myocardial infraction or bleeding, Hemodynamic effects were compared in 45 hypertensive coronary bypass patients randomized to receive either diltiazem, nitroglycerin, or sodium nitroprusside. Diltiazem was administered as an intravenous bolus of 0.3 mg·kg−1 within 5 min, followed by infusion of 0.1–0.8 mg·kg−1·h−1 in group 1. Nitroglycerin was infused at a rate of 1–3 μg·kg·h−1 in group 2, and sodium nitroprusside was given at a rate of 1–3 μg·kg−1·min−1 in group 3. Hemodynamic measurements were carried out before infusion (T1) and at 30 min (T2), 2 h (T3), and 12 h (T4) after initiation of treatment in the intensive care unit. Mean arterial pressure decreased significantly in all groups. There were no differences among groups at T1 and T2. At T3, heart rate in group 2 was significantly higher than group 1. At T3 and T4, the double product was highest in group 3 (group 1 vs. 3, p < 0.001). These results suggest that the hemodynamic effects of the 3 drugs are similar within the first 30 min. However, after 30 min, diltiazem affords better myocardial performance and more effective control of hypertension.


Perfusion | 2002

Adjustment of sweep gas flow during cardiopulmonary bypass.

Hasan Karabulut; Fevzi Toraman; Sümer Tarcan; Önder Demirhisa; Cem Alhan

Cardiopulmonary bypass (CPB) is one of the major tools of cardiac surgery. However, no clear data are available for the ideal value of sweep gas flow to oxygenator during CPB. The aim of this study was to determine the best value for sweep gas flow during CPB. Thirty patients undergoing isolated CABG were randomly and equally allocated into three groups. Sweep gas flow to oxygenator was kept at 1.35 l/min/m2 in group 1, 1.60 l/min/m2 in group 2, and 2.0 l/min/m2 in group 3. All patients were operated on under the same anaesthetic regime and surgical techniques. Samples for blood gas analysis were collected at T1: before CPB; T2: 5 min after the initiation of CPB; T3: just before rewarming; and T4: at the end of rewarming. Five minutes after the initiation of CPB (T2), pCO2 decreased significantly in groups 2 and 3 compared to group 1 ( p < 0.02). With the addition of hypothermia (T3), the changes in the pH and pCO2 became more profound and, in this period, the levels in group 3 patients outranged the physiologic limits, with pCO2 and pH values being 28± 3 mmHg and 7.50± 0.04, respectively. At the end of the rewarming period (T4), in spite of increased carbon dioxide production, pCO2 values were below the physiologic limits in groups 2 and 3. We conclude that sweep gas flow to the oxygenator should be kept between 1.35 and 1.60 l/min/m2 during CPB to avoid hypocapnia, which results in alkalosis and has hazardous effects on lung mechanics, cerebral blood flow, and the cardiovascular system.

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Murat Yuce

University of Gaziantep

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