Effect of different priming fluids on extravascular lung water, cell integrity and oxidative stress in cardiopulmonary bypass surgery.

BACKGROUND: Discussions continue on the ideal priming fluid in adult cardiac surgery. The purpose of this prospective study was to evaluate the effects of different types of priming fluids on extravascular lung water, cell integrity and oxidative stress status. METHODS: Thirty elective coronary artery bypass surgery patients were randomised prospectively into two groups. The first group received colloid priming fluid, while the second group received crystalloid priming fluid. Extravascular lung water index, advanced oxidative protein products, total thiol, free haemoglobin, ischaemic modified albumin and sialic acid levels were measured. Moreover, intra-operative and postoperative outcomes were reviewed. RESULTS: There were no significant differences between the groups with regard to extravascular lung water index, oxidative stress parameters or cell integrity (p > 0.05). Similarly, no significant differences were observed between the patients with regard to intra-operative and postoperative outcomes (p > 0.05). CONCLUSIONS: The presumed superiority of colloidal priming for cardiopulmonary bypass could not be confirmed in our study.

Retrograde autologous priming method reduces plasma free hemoglobin level in aortic surgery.

Background: Although conventional cardiopulmonary bypass (cCPB) is still the most widely used method in open heart surgery, methods such as retrograde autologous priming (RAP) are increasingly popular in terms of limiting hemodilution. Our hypothesis is that the use of the RAP method in aortic surgery may result in a limitation of hemodilution and a decrease in fHb levels. For this purpose, plasma free hemoglobin (fHb) levels were investigated in adult open aortic arch repair with axillary artery cannulation patients using cCPB and rRAP methods. Materials and Methods: In this study, a total of 36 patients undergoing aortic surgery using rRAP and standard cCPB were investigated. Measurements were performed at five time points: After induction of anesthesia, 5th minute of CPB, 10th minute of antegrade cerebral perfusion, 30th minute after declamping of aorta, and at sternum closure. Besides hemodynamic variables, arterial blood gas analysis and postoperative variables, patients were assessed for fHb levels. Results: The rRAP group had a significantly lower increase in fHb levels in T3, T4, and T5 time points, when compared to the cCPB group (p = 0.002, 0.047, 0.009, respectively). There was no significant difference between the rRAP and cCPB groups in other intraoperative, and postoperative variables. Also, it was observed that rRAP did not make a difference in terms of blood and blood product transfusion. Conclusion: In this study, in patients undergoing aortic surgery, a reduction in the increase of fHb was observed with the rRAP method which is a simple procedure that does not require high cost or advanced technology.

Effects of short-term hyperoxic ventilation on lung, kidney, heart, and liver in a rat model: A biochemical evaluation.

BACKGROUND: Despite studies on the adverse effects of hyperoxia, its use is still recommended by the World Health Organization. The aim of this study was to test the possible harmful effects of hyperoxia on the lung, kidney, heart, and liver in a rat mechanical ventilation model. METHODS: Male Wistar rats were randomly assigned into two groups (n=6/group): Normoxic (FiO2: 0.3) or hyperoxic (FiO2: 1.0) ventilation for 4 h. The injury was evaluated in bronchoalveolar lavage (BAL), blood, lung, liver, kidney, and heart was evaluated in terms of cell surface integrity, extracellular matrix (sialic acid, syndecan-1), osmotic stress (free hemoglobin), and redox homeostasis-lipid peroxidaation (malondialdehyde). BAL and wet/dry weight ratio were also evaluated for cellular permeability. RESULTS: Four hours of hyperoxic ventilation did not lead to significant changes in (1) sialic acid, syndecan-1, (2) malondialdehyde levels and wet/dry weight ratio in liver, kidney, heart, and lung compared to normoxic ventilation. CONCLUSION: Mechanical ventilation with hyperoxia seems to have almost similar effects compared to ventilation with normoxia. However, the long term effect of hyperoxia should be evaluated.

Effects of upper limb ischemia-reperfusion on regional oxidative stress during aortic surgery with moderate hypothermia.

INTRODUCTION: This study aims to evaluate the effect of acute, iatrogenic right arm ischemia and reperfusion (I/R) due to right axillary cannulation on regional oxidative stress using tissue perfusion markers such as central venous oxygen saturation, lactate, the difference between central venous and arterial CO2 pressure, near-infrared spectroscopy (NIRS) measurements, and biomarkers like sialic acid, malondialdehyde, advanced oxidative protein products in aortic surgery with moderate hypothermia. METHODS: Adult patients undergoing ascending aorta repair with antegrade cerebral perfusion via the axillary artery participated. Blood samples were collected from the internal jugular vein, right arm cubital vein, and left arm cubital vein, and analysis was performed at intraoperative time points. RESULTS: Right-arm venous oxygen saturation levels are significantly lower than left arm and central venous, as expected in iatrogenic ischemia. Right arm lactate levels are significantly higher. Somatic right arm NIRS values are significantly lower than somatic left arm. There are no significant differences for biomarkers throughout the time points. CONCLUSIONS: We have concluded that well-known markers reflect the results of ischemia-reperfusion more rapidly, and are more valuable than novel biomarkers. NIRS is a promising monitor in terms of providing information about tissue oxygenation. Oxidative stress biomarkers do not change quickly enough to give useful information in a short enough period of time; moreover, their costs are high and laboratory studies take time. Although axillary cannulation is controlled limb ischemia, the local effects of I/R did not completely normalize at the end of the surgery, and this regional I/R did not affect the global body organism.

Biochemical markers decrease and increase disproportionally in A1 pulley tissue of type 2 diabetic trigger finger patients.

OBJECTIVES: This study aims to detect the levels of some biochemical markers in A1 pulley tissue of type 2 diabetic trigger finger patients to enlighten the mechanisms leading to cellular complications. PATIENTS AND METHODS: The study included 35 trigger finger patients (5 males, 30 females; mean age 53.9±9.15 years; range, 37 to 71 years). We measured total thiol (total-SH) levels to determine the status of the non-enzymatic antioxidant defense system and advanced oxidation protein product (AOPP) levels to determine levels of oxidative protein modification in pulley tissues of trigger finger patients with or without diabetes. Extracellular matrix degradation was assessed by measuring levels of sialic acid (SA) in the pulley tissue. RESULTS: Total-SH values for the groups with and without diabetes were 22.7±1.6 vs. 38.9±5.2 nmol/mg protein, respectively, while AOPP values were 472.5±131.6 vs.175.6±9.9 mmol/g protein, respectively. The SA levels of diabetic and nondiabetic patients were 0.4±0.0 vs. 0.63±0.1 nmol/mg protein, respectively. CONCLUSION: Our results revealed that tissue SA levels and tissue SH levels decreased and AOPP levels increased disproportionally in the A1 pulley tissue of diabetic patients, which may indicate the role of oxidative protein damage and extracellular matrix changes in diabetic trigger finger etiology.

Effects of Alprazolam and Melatonin Used for Premedication on Oxidative Stress, Glicocalyx Integrity and Neurocognitive Functions.

OBJECTIVE: The purpose of this investigation was to compare the effect of alprazolam and melatonin on oxidative stress, glicocalyx integrity and neurocognitive function in patients undergoing coronary artery bypass grafting (CABG). METHODS: Overall, 42 patients undergoing CABG were retrospectively included in this study. Blood samples which preserved at -70°C for a previous study were used for this study. The participants were divided into two groups. Patients in the Group A were administered alprazolam before the operation, whereas melatonin was used for premedication in the Group M. Blood samples were collected at three time points [T0: before anaesthesia induction, T1: admittance to intensive care unit (ICU), T2: 24 h after ICU admission], and oxidative stress parameters and glicocalyx integrity were evaluated. Furthermore, Mini-Mental State Examination was recorded to measure neurocognitive function. RESULTS: The total thiol levels which were measured as an antioxidant parameter were significantly higher, and free Hb values were significantly lower in the Group M compared to the Group A (p<0.05). No significant differences were found in order to oxidative stress parameter levels, extubation time, length of hospital stay, durations of cross-clamp, cardiopulmonary bypass and operation and Mini-Mental State Examination results between the two groups (p>0.05). CONCLUSION: In light of positive effects on oxidatif stress parameters, melatonin may be considered as a good and safe premedication agent with its anxiolytic, antioxidant and minimal haemodynamic and respiratory effects.

Unilateral Antegrade Cerebral Perfusion and Moderate Hypothermia: Assessing Safety With Novel Biomarkers.

BACKGROUND: Antegrade cerebral perfusion in aortic surgery is a well-established brain protection method. Open distal anastomosis during aortic surgery has some well-known advantages. Antegrade cerebral perfusion allows repair to some extent of the aortic arch, even in isolated ascending aortic aneurysm. The present study aims to investigate the adequacy of contralateral perfusion with novel oxidative stress parameters during unilateral antegrade cerebral perfusion. METHOD: The study included 30 consecutive patients undergoing thoracic aortic surgery with unilateral antegrade cerebral perfusion (uACP) under moderate hypothermia (28° C). Blood samples from right and left jugular vein were obtained at four time intervals during surgery (after the anaesthetic induction - Phase 1, at the beginning of cardiopulmonary bypass - Phase 2, 15th minute of uACP - Phase 3 and after weaning from cardiopulmonary bypass - Phase 4). Novel oxidative stress parameters (advanced oxidation protein products, sialic acid, thiol reagents and ischaemia-modified serum albumin), blood gas analysis, and serum glucose and lactate levels were measured. In addition, intraoperative and early postoperative follow-up parameters were recorded. RESULTS: Mean unilateral antegrade cerebral perfusion time was observed to be 16.4±5.9min (9 - 46min). No significant differences between right and left hemispheres were observed in novel oxidative parameters or biochemical values. There was only one temporary neurological deficit (3.3%) in the patient group. CONCLUSIONS: The present study demonstrated that open distal anastomosis for hemiarch repair can be performed safely with unilateral antegrade cerebral perfusion under moderate hypothermia with both clinical outcome and novel biomarkers.