Effect of iron deficiency without anaemia on days alive and out of hospital in patients undergoing valvular heart surgery.

Comprehensive evidence regarding the treatment of non-anaemic iron deficiency in patients undergoing valvular heart surgery is lacking. This study aimed to investigate the association between non-anaemic iron deficiency and postoperative outcomes in these patients. We retrospectively analysed 321 patients of which 180 (56%) had iron deficiency (defined as serum ferritin < 100 ng.ml-1 or < 300 ng.ml-1 with transferrin saturation < 20%). While the iron-deficient group had lower pre-operative haemoglobin levels than the non-iron deficient group (median (IQR [range]) 134 (127-141 [120-172]) g.l-1 , 143 (133-150 [120-179]) g.l-1 , p = 0.001), there was no between-group difference in allogeneic red blood cell transfusion. Median (IQR [range]) days alive and out of hospital at postoperative day 90 was 1 day shorter in the iron-deficient group (80 (77-82 [9-85]) days vs. 81 (79-83 [0-85]) days, p = 0.026). In multivariable analysis, only cardiopulmonary bypass duration (p = 0.032) and intra-operative allogeneic red blood cell transfusion (p = 0.011) were significantly associated with reduced days alive and out of hospital at postoperative day 90. Iron deficiency did not exert any adverse influence on secondary outcomes except length of hospital stay. Our findings indicate that non-anaemic iron deficiency alone is not associated with adverse effects in patients undergoing valvular heart surgery when it does not translate into an increased risk of allogeneic transfusion.

Unveiling the neuromechanical mechanisms underlying the synergistic interactions in human sensorimotor system.

Motor synergies are neural organizations of a set of redundant motor effectors that interact with one another to compensate for each other's error and ensure the stabilization of a performance variable. Recent studies have demonstrated that central nervous system synergistically coordinates its numerous motor effectors through Bayesian multi-sensory integration. Deficiency in sensory synergy weakens the synergistic interaction between the motor effectors. Here, we scrutinize the neuromechanical mechanism underlying this phenomenon through spectral analysis and modeling. We validate our model-generated results using experimental data reported in the literature collected from participants performing a finger force production task with and without tactile feedback (manipulated through injection of anesthetic in fingers). Spectral analysis reveals that the error compensation feature of synergies occurs only at low frequencies. Modeling suggests that the neurophysiological structures involving short-latency back-coupling loops similar to the well-known Renshaw cells explain the deterioration of synergy due to sensory deprivation.

Remote ischaemic conditioning for prevention of acute kidney injury after valvular heart surgery: a randomised controlled trial.

BACKGROUND: Repeated remote ischaemic conditioning (RIC) during weaning from cardiopulmonary bypass and in the early postoperative period may confer protection against acute kidney injury (AKI). We evaluated the effect of repeated RIC on the incidence of AKI in patients undergoing valvular heart surgery. METHODS: Patients were randomised into either the RIC (n=120) or control (n=124) group. A pneumatic tourniquet was placed on each patient's thigh. Upon removal of the aortic cross-clamp, three cycles of inflation for 5 min at 250 mm Hg (with 5 min intervals) were applied in the RIC group. Additionally, three cycles of RIC were repeated at postoperative 12 and 24 h. AKI was diagnosed based on the Kidney Disease: Improving Global Outcomes guideline. The incidences of renal replacement therapy, permanent stroke, sternal wound infection, newly developed atrial fibrillation, mechanical ventilation >24 h, and reoperation for bleeding during hospitalisation were recorded. RESULTS: The incidences of AKI were not significantly different between the control (19.4%) and RIC (15.8%) groups (a difference of 3.5 percentage points; 95% confidence interval: -6.8%-13.9%; P=0.470). Perioperative serum creatinine concentrations were similar in the control and RIC groups (P=0.494). Fluid balance, urine output, blood loss, transfusion, and vasopressor/inotropic requirements were not significantly different between the groups (all P>0.05). The occurrences of a composite of morbidity and mortality endpoints were not significantly different between the control (46.0%) and RIC (39.2%) groups (a difference of 6.8 percentage points; 95% confidence interval: -6.4%-20.0%; P=0.283). CONCLUSIONS: The results of our study do not support repeated RIC to decrease the incidence of AKI after valvular heart surgery. CLINICAL TRIAL REGISTRATION: NCT02720549.

Supplementation with nutrients modulating insulin-like growth factor-1 negatively correlated with changes in the levels of pro-inflammatory cytokines in community-dwelling elderly people at risk of undernutrition.

BACKGROUND: Suboptimal nutrition accompanied by chronic low-grade increases in circulating cytokine levels is more common in elderly people. We explored the improvement in nutritional status, especially in the level of insulin-like growth factor-1 (IGF-1) and its relationship with changes in circulating cytokine levels, after providing extra protein and energy content to community-dwelling older adults at risk of undernutrition. METHODS: Sixty nondiabetic subjects, aged ≥65 years and living independently in a community for elderly people, with a serum pre-albumin level ≤30 mg dL-1 and a body mass index <25 kg m-2 , were recruited. The subjects were followed for a 2-week pre-intervention period, during which they maintained routine dietary habits. This was followed by an intervention period, during which they received oral nutritional supplementation for 2 weeks. RESULTS: Following 2 weeks of intervention, there were significant increases in total lymphocyte count (TLC) and insulin-like growth factor (IGF)-1, pre-albumin and transferrin compared to baseline. Body weight and mid-arm circumference significantly increased without alteration of tricep skinfold thickness at the end of the intervention. There was a significant reduction in interleukin (IL)-6 levels and a trend toward a decrease in the tumor necrosis factor (TNF)-α levels. At baseline, age was negatively correlated with IGF-1 levels and positively correlated with IL-6 and TNF-α levels. The change (▵, from baseline) in IGF-1 level was positively correlated with age and negatively correlated with ▵IL-6 and ▵TNF-α. CONCLUSIONS: A 2-week intervention with oral nutritional supplementation improved nutritional status and decreased circulating cytokine levels. Specifically, ▵IGF-1 was negatively correlated with changes in pro-inflammatory cytokine levels in community-dwelling elderly people at risk of undernutrition. (Clinicaltrials.gov: NCT02656186).

Conservation implications of the genetic diversity of Gymnospermium microrrhynchum in Korea.

Gymnospermium microrrhynchum (Berberidaceae) is an ephemeral perennial herb with a limited distributional range in the Baekdudaegan mountain areas of the Korean Peninsula, and is designated a rare plant by the Korean Forest Service. Information about its genetic variation and structure is important for developing successful conservation strategies. To investigate the genetic variation within and among seven G. microrrhynchum populations, random amplified polymorphic DNA data were obtained for 207 individuals. The populations exhibited relatively low genetic diversity: the percentage of polymorphic bands (PPB) ranged from 32.1 to 66.7% (mean = 51.4%) and Nei's gene diversity (HE) ranged from 0.116 to 0.248 (mean = 0.188). However, genetic diversity at the species level was relatively high (PPB = 98.7%, HE = 0.349). An analysis of molecular variance revealed high differentiation among populations (ΦST = 0.6818), but the low gene flow value (Nm = 0.117) suggests a low level of gene exchange occurs among populations. Principal coordinates analysis revealed that individuals were separated according to population. The high level of genetic differentiation and restricted gene flow among G. microrrhynchum populations, which resulted from their isolation in alpine areas after the Ice Age, indicates that it is essential to protect and manage all populations, rather than focus on specific populations, in order to maintain the genetic diversity of this species.

Sodium bicarbonate does not prevent postoperative acute kidney injury after off-pump coronary revascularization: a double-blinded randomized controlled trial.

BACKGROUND: Acute kidney injury (AKI) is a common morbidity after off-pump coronary revascularization. We investigated whether perioperative administration of sodium bicarbonate, which might reduce renal injury by alleviating oxidative stress in renal tubules, prevents postoperative AKI in off-pump coronary revascularization patients having renal risk factors. METHODS: Patients (n=162) having at least one of the following AKI risk factors were enrolled: (i) age >70 yr; (ii) diabetes mellitus; (iii) chronic renal disease; (iv) congestive heart failure or left ventricular ejection fraction <35%; and (v) reoperation or emergency. Patients were evenly randomized to receive either sodium bicarbonate (0.5 mmol kg-1 for 1 h upon induction of anaesthesia followed by 0.15 mmol kg-1 h-1 for 23 h) or 0.9% saline. Acute kidney injury within 48 h after surgery was assessed using the Acute Kidney Injury Network criteria. RESULTS: The incidences of AKI were 21 and 26% in the bicarbonate and control groups, respectively (P=0.458). Serially measured serum creatinine concentrations and perioperative fluid balance were also comparable between the groups. The length of postoperative hospitalization and incidence of morbidity end points were similar between the groups, whereas significantly more patients in the bicarbonate group required prolonged mechanical ventilation (>24 h) relative to the control group (20 vs 6, P=0.003). CONCLUSIONS: Perioperative sodium bicarbonate administration did not decrease the incidence of AKI after off-pump coronary revascularization in high-risk patients and might even be associated with a need for prolonged ventilatory care. CLINICAL TRIAL REGISTRATION: NCT01840241.

Comparison of positive end-expiratory pressure-induced increase in central venous pressure and passive leg raising to predict fluid responsiveness in patients with atrial fibrillation.

BACKGROUND: Positive end-expiratory pressure (PEEP)-induced increase in central venous pressure (CVP) has been suggested to be a robust indicator of fluid responsiveness, with heart rhythm having minimal influence. We compared the ability of PEEP-induced changes in CVP with passive leg raising (PLR)-induced changes in stroke volume index (SVI) in patients with atrial fibrillation after valvular heart surgery. METHODS: In 43 patients with atrial fibrillation after cardiac surgery, PEEP was increased from 0 to 10 cm H2O for 5 min and changes in CVP were assessed. After returning the PEEP to 0 cm H2O, PLR was performed for 5 min and changes in SVI were recorded. Finally, 300 ml of colloid was infused and haemodynamic variables were assessed 5 min after completion of a fluid challenge. Fluid responsiveness was defined as an increase in SVI ≥10% measured by a pulmonary artery catheter. RESULTS: Fifteen (35%) patients were fluid responders. There was no correlation between PEEP-induced increases in CVP and changes in SVI after a fluid challenge (ß coefficient -0.052, P=0.740), whereas changes in SVI during PLR showed a significant correlation (ß coefficient 0.713, P<0.001). The area under the receiver operating characteristic curve of the PEEP-induced increase in CVP and changes in SVI during PLR for fluid responsiveness was 0.556 [95% confidence interval (CI) 0.358-0.753, P=0.549) and 0.771 (95% CI 0.619-0.924, P=0.004), respectively. CONCLUSIONS: A PEEP-induced increase in CVP did not predict fluid responsiveness in patients with atrial fibrillation after cardiac surgery, but increases in SVI during PLR seem to be a valid predictor of fluid responsiveness in this subset of patients.

Respirophasic carotid artery peak velocity variation as a predictor of fluid responsiveness in mechanically ventilated patients with coronary artery disease.

BACKGROUND: We studied respirophasic variation in carotid artery blood flow peak velocity (ΔVpeak-CA) measured by pulsed wave Doppler ultrasound as a predictor of fluid responsiveness in mechanically ventilated patients with coronary artery disease. METHODS: Forty patients undergoing elective coronary artery bypass surgery were enrolled. Subjects were classified as responders if stroke volume index (SVI) increased ≥15% after volume expansion (6 ml kg(-1)). The ΔVpeak-CA was calculated as the difference between the maximum and minimum values of peak velocity over a single respiratory cycle, divided by the average. Central venous pressure, pulmonary artery occlusion pressure, pulse pressure variation (PPV), and ΔVpeak-CA were recorded before and after volume expansion. RESULTS: PPV and ΔVpeak-CA correlated significantly with an increase in SVI after volume expansion. Area under the receiver-operator characteristic curve (AUROC) of PPV and ΔVpeak-CA were 0.75 [95% confidence interval (CI) 0.59-0.90] and 0.85 (95% CI 0.72-0.97). The optimal cut-off values for fluid responsiveness of PPV and ΔVpeak-CA were 13% (sensitivity and specificity of 0.74 and 0.71) and 11% (sensitivity and specificity of 0.85 and 0.82), respectively. In a subgroup analysis of 17 subjects having pulse pressure hypertension (≥ 60 mm Hg), PPV failed to predict fluid responsiveness (AUROC 0.70, P=0.163), whereas the predictability of ΔVpeak-CA remained unchanged (AUROC 0.90, P=0.006). CONCLUSIONS: Doppler assessment of respirophasic ΔVpeak-CA seems to be a highly feasible and reliable method to predict fluid responsiveness in mechanically ventilated patients undergoing coronary revascularization. CLINICAL TRIAL REGISTRATION: NCT 01836081.

Effect of ketamine as an adjunct to intravenous patient-controlled analgesia, in patients at high risk of postoperative nausea and vomiting undergoing lumbar spinal surgery.

BACKGROUND: We evaluated the effect of ketamine as an adjunct to a fentanyl-based i.v. patient-controlled analgesia (IV-PCA) on postoperative nausea and vomiting (PONV) in patients at high risk of PONV undergoing lumbar spinal surgery. METHODS: Fifty non-smoking female patients were evenly randomized to either the control or ketamine group. According to randomization, patients received either ketamine 0.3 mg kg(-1) i.v. or normal saline after anaesthetic induction with fentanyl-based IV-PCA either with or without ketamine mixture (3 mg kg(-1) in 180 ml). The incidence and severity of PONV, volume of IV-PCA consumed, and pain intensity were assessed in the postanaesthesia care unit, and at postoperative 6, 12, 24, 36, and 48 h. RESULTS: The overall incidence of PONV during the first 48 h after surgery was similar between the two groups (68 vs 56%, ketamine and control group, P=0.382). The total dose of fentanyl used during the first 48 h after operation was lower in the ketamine group than in the control group [mean (SD), 773 (202) µg vs 957 (308) µg, P=0.035]. The intensity of nausea (11-point verbal numerical rating scale) was higher in the ketamine group during the first 6 h after operation [median (interquartile range), 6 (3-7) vs 2 (1.5-3.5), P=0.039], postoperative 12-24 h [5 (4-7) vs 2 (1-3), P=0.014], and postoperative 36-48 h [5 (4-7) vs 2 (1-3), P=0.036]. Pain intensities were similar between the groups. CONCLUSIONS: Ketamine did not reduce the incidence of PONV and exerted a negative influence on the severity of nausea. It was, however, able to reduce postoperative fentanyl consumption in patients at high-risk of PONV.

Validation of pulse pressure variation and corrected flow time as predictors of fluid responsiveness in patients in the prone position.

BACKGROUND: The aim of this prospective trial was to investigate the ability of pulse pressure variation (PPV) and corrected flow time (FTc) to predict fluid responsiveness in the prone position. METHODS: Forty-four patients undergoing lumbar spine surgery in the prone position on a Wilson frame were prospectively studied. PPV and FTc were measured before and after a colloid bolus (6 ml kg(-1)) both in the supine and in the prone positions. Fluid responsiveness was defined as an increase in the stroke volume index of ≥ 10% as measured by oesophageal Doppler. RESULTS: In the supine position, 26 patients were responders and the areas under the curve (AUC) of the receiver-operator characteristic (ROC) curves of PPV and FTc were 0.935 [95% confidence interval (CI): 0.870-0.999, P<0.001] and 0.822 (95% CI: 0.682-0.961, P<0.001), respectively. The optimal cut-off PPV and FTc values were 15% (sensitivity 73%, specificity 94%) and 358 ms (sensitivity 88%, specificity 78%), respectively. In the prone position, 34 patients were responders and the AUCs of PPV and FTc were 0.969 (95% CI: 0.912-1.000, P<0.001) and 0.846 (95% CI: 0.706-0.985, P=0.001), respectively. The optimal cut-off PPV and FTc values were 14% (sensitivity 97%, specificity 90%) and 331 ms (sensitivity 77%, specificity 90%), respectively. CONCLUSIONS: While the predictability of PPV was significantly higher than that of FTc in the prone position, both variables showed high predictability and remained as useful indices for guiding fluid therapy in prone patients with minimal alterations in their optimal cut-off values to predict fluid responsiveness. Clinical trial registration URL: http://www.clinicaltrials.gov/ct2/show/NCT01646359?term=NCT01646359&rank=1 and unique identification number NCT01646359.

Myocardial protection by glucose-insulin-potassium in acute coronary syndrome patients undergoing urgent multivessel off-pump coronary artery bypass surgery.

BACKGROUND: The aim of this randomized and controlled trial was to investigate the effect of a glucose-insulin-potassium (GIK) solution on myocardial protection in acute coronary syndrome (ACS) patients undergoing urgent multivessel off-pump coronary artery bypass (OPCAB) surgery. METHODS: Sixty-six patients were randomly allocated either to receive 0.3 ml kg(-1) h(-2) GIK solution (potassium 80 mEq and regular insulin 325 IU in 500 ml of 50% glucose) or equivalent volume of normal saline (control) upon anaesthetic induction until 6 h after reperfusion. The primary endpoints were to compare the concentrations of creatine kinase-MB (CK-MB) and troponin-T between the groups after reperfusion. The secondary endpoints were to compare the incidences of postoperative troponin-T >0.8 ng ml(-1) and myocardial infarction (MI) between the groups. RESULTS: Highest CK-MB [8.7 (4.4) vs 13.1 (7.9) ng ml(-1), P=0.006] and troponin-T [0.20 (0.13-0.49) vs 0.48 (0.18-0.91) ng ml(-1), P<0.0001] values after reperfusion were significantly lower in the GIK group compared with the control group. The area under the curve of serially measured troponin-T was also significantly smaller in the GIK group compared with the control group [0.83 (0.43-1.81) vs 0.46 (0.31-1.00), P=0.036]. Significantly fewer patients in the GIK group showed troponin-T >0.8 ng ml(-1) after reperfusion compared with the control group (3 vs 11, P=0.033). The incidence of postoperative MI was similar between the groups. CONCLUSIONS: GIK administration in ACS patients undergoing urgent multivessel OPCAB significantly attenuated the degree of ensuing myocardial injury without complications related to glycaemic control. Clinical Trial Registry. URL: http://clinicaltrials.gov/ct2/show/NCT01384656?term=GIK+AND+OPCAB&rank=1. Unique identification number NCT01384656.

Prognostic value of a tissue Doppler-derived index of left ventricular filling pressure on composite morbidity after off-pump coronary artery bypass surgery.

BACKGROUND: The ratio of early transmitral flow velocity to early diastolic velocity of the mitral annulus (E/e') is an indicator of diastolic function that correlates well with left ventricular (LV) filling pressure and is relatively independent of systolic function and rhythm abnormalities. We prospectively evaluated the predictive value of E/e' for postoperative outcome in patients undergoing off-pump coronary artery bypass graft surgery (OPCAB). METHODS: Patients undergoing OPCAB were classified into three groups according to their E/e' ratio: (i) normal E/e' <8; (ii) undetermined E/e' ≥8 and ≤15; and (iii) elevated E/e' >15. Among those with E/e' between 8 and 15, patients with elevated LV filling pressure were further identified by comprehensive Doppler examination. These patients were classified as having a high LV filling pressure, together with patients who had E/e' ratios >15. Univariate and multivariate regression analyses were used to evaluate the relationship between preoperative variables and composite endpoints for morbidity. RESULTS: In univariate analysis, diabetes mellitus, recent myocardial infarction, chronic obstructive pulmonary disease, serum creatinine (sCr) concentration, E/e' >15, high LV filling pressure, LV ejection fraction, New York Heart Association class III and IV, and use of diuretics were significant risk factors for postoperative morbidity. In multivariate regression analysis of these variables, only sCr (odds ratio 1.4) and E/e' >15 (odds ratio 2.4) or high LV filling pressure (odds ratio 2.8) remained as independent risk factors. CONCLUSIONS: E/e' ratio >15 was a significant predictor of composite endpoints of postoperative morbidity. We suggest that E/e' ratio should be included in the routine preoperative assessment of patients presenting for OPCAB.

Cardiac displacement-induced hemodynamic instability during off-pump coronary artery bypass surgery and its predictors.

BACKGROUND: Emergent conversion to an on-pump procedure during an off-pump coronary artery bypass surgery (OPCAB) due to hemodynamic instability is associated with increased morbidity and mortality. The aim of this study was to evaluate the predictors of hemodynamic instability associated with mechanical heart displacement during OPCAB and the fate of these patients. METHODS: Data of 494 patients who underwent elective, isolated OPCAB between December 2006 and April 2010 were reviewed. Hemodynamic instability was defined as mixed venous oxygen saturation (SvO(2) ) <60% during grafting. Pre-operative variables including the presence of diastolic dysfunction and mitral regurgitation (MR) were evaluated for their predictive value for hemodynamic instability by logistic regression analysis. Outcome variables were also compared between patients who developed hemodynamic instability and those who did not. RESULTS: In univariate analysis, body mass index, diabetes mellitus, chronic obstructive pulmonary disease (COPD), left ventricular ejection fraction, diastolic dysfunction, MR ≥ grade 1, higher creatinine and the use of diuretics were identified as risk factors. In multivariate analysis of these variables, COPD and creatinine remained as independent risk factors for hemodynamic instability. These patients also had significantly lower cardiac output and SvO(2) after sternum closure and a higher incidence of composite morbidity end points. CONCLUSION: COPD and pre-operative creatinine level were identified as independent risk factors of mechanical heart displacement-induced hemodynamic instability during OPCAB. As these patients were associated with significantly lower SvO(2) even at the end of surgery and with adverse outcome, consideration may be given to initiate preemptive measures to increase SvO(2) before or during grafting.

Effect of N-acetylcysteine on pulmonary function in patients undergoing off-pump coronary artery bypass surgery.

BACKGROUND: Pulmonary dysfunction related to inflammatory response and radical oxygen species remains a problem in off-pump coronary bypass graft surgery (OPCAB), especially in patients with reduced left ventricular (LV) function. The aim of this study was to evaluate the effect of N-acetylcysteine (NAC) on pulmonary function following OPCAB. METHODS: Patients with LV ejection fraction ≤40% were randomly assigned to receive either a bolus of 100 mg/kg of intravenous NAC over a 15-min period immediately after anesthetic induction, followed by an intravenous infusion at 40 mg/kg/day for 24 h (NAC group, n=24), or a placebo (control group, n=24). Hemodynamic and pulmonary parameters, and the incidence of acute lung injury (PaO(2)/FiO(2)<300 mmHg) were assessed and compared. RESULTS: The pulmonary vascular resistance index (PVRI) did not change during mechanical heart displacement compared with the baseline value in the NAC group while it was significantly increased in the control group. Significantly less number of patients developed acute lung injury at 2 h after the surgery in the NAC group. The other pulmonary parameters and the duration of ventilator care were all similar. CONCLUSIONS: NAC demonstrated promising results in terms of mitigating the increase in PVRI during mechanical heart displacement and attenuating the development of acute lung injury in the immediate post-operative period. However, NAC could not induce a definite improvement in the other important pulmonary variables including PaO(2)/FiO(2) and Q(s)/Q(t), and did not lead to a decreased duration of ventilatory care or length of stay in the intensive care unit.

Effects of propofol on the expression of matric metalloproteinases in rat cardiac fibroblasts after hypoxia and reoxygenation.

BACKGROUND: Propofol is known to protect the myocardium against ischaemia/reperfusion (I/R) injury through its antioxidant and anti-inflammatory properties. Matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) are involved in cell migration and invasion, and mediate tissue remodelling during I/R injury. They are regulated by various mechanisms including oxidative stress and AKT and ERK pathways. We investigated whether propofol affected the expression of MMPs and subsequent cell migration and invasion and the signalling pathways involved in primary rat cardiac fibroblasts undergoing hypoxia and reoxygenation. METHODS: The phosphorylation of ERK and AKT signalling pathways was examined by western blot analysis in rat primary cardiac fibroblasts after hypoxia and reoxygenation. mRNA expression of MMP and TIMPS was analysed by real-time PCR, and proteolytic activities of MMP-2 and -9 were assessed. The effects of propofol on migration, invasion, wound healing, and cell proliferation activity were evaluated after reoxygenation. RESULTS: Propofol induced AKT and ERK1/2 activation. Subsequent activation of MMPs resulted in increased cell migration, invasion, and wound-healing activity under hypoxia-reoxygenation, which was decreased by LY294002 (AKT inhibitor) and U0126 (ERK inhibitor) in rat cardiac fibroblasts. However, propofol had no effect on proliferation or viability of cardiac fibroblasts after hypoxia-reoxygenation. CONCLUSIONS: Propofol affected the expression of MMPs and TIMPs and subsequently induced cell migration and invasive ability, through activation of the ERK and AKT signalling pathway in hypoxia-reoxygenated rat cardiac fibroblasts.

Comparing the effects of 5% albumin and 6% hydroxyethyl starch 130/0.4 on coagulation and inflammatory response when used as priming solutions for cardiopulmonary bypass.

AIM: This prospective, randomized and controlled trial compares the use of human albumin (HA) and hydroxyethyl starch (HES) 130/0.4 in the priming solution for a non-biocompatible cardiopulmonary bypass (CPB) circuit. The effects of each substance on coagulation, postoperative blood loss and pro-inflammatory activities were examined. METHODS: Thirty-six adult patients undergoing mitral valvular heart surgery were randomly assigned to either the HA or HES group; 500 mL of 5% HA or 6% HES 130/0.4 were added to the priming solution of the CPB circuit for each group, respectively. Coagulation variables were measured perioperatively; these variables included thromboelastographic (TEG) parameters and pro-inflammatory markers such as interleukin (IL)-6, IL-8 and tumor necrotic factor (TNF)-a. Postoperative blood loss and transfusion requirements were also assessed. RESULTS: There were no significant intergroup differences in the coagulation variables (including TEG parameters), serum concentrations of IL-6, IL-8 and TNF-a, and blood loss or transfusion requirements. TEG parameters, which indicate the speed of solid clot formation and the strength of the fibrin clot, decreased up to 4 hours after CPB in both groups. Serum concentrations of IL-6, IL-8 and TNF-a were higher up to 12 hours after surgery compared to baseline values in both groups. Hemoglobin levels and platelet counts were lower up to 12 hours after surgery compared to baseline values in both groups. CONCLUSION: HES 130/0.4 was comparable to albumin as a component of the priming solution for a non-biocompatible CPB circuit. The two substances showed similar effects on coagulation variables, blood loss and pro-inflammatory activities in adult patients undergoing mitral valvular heart surgery.

Remifentanil protects myocardium through activation of anti-apoptotic pathways of survival in ischemia-reperfused rat heart.

Remifentanil is a commonly used opioid in anesthesia with cardioprotective effect in ischemia-reperfused (I/R) heart. We evaluated the influence of remifentanil on myocardial infarct size and expressions of proteins involved in apoptosis in I/R rat heart following various time protocols of remifentanil administration. Artificially ventilated anesthetized Sprague-Dawley rats were subjected to a 30 min of left anterior descending coronary artery occlusion followed by 2 h of reperfusion. Rats were randomly assigned to one of five groups; Sham, I/R only, remifentanil preconditioning, postconditioning and continuous infusion group. Myocardial infarct size, the phosphorylation of ERK1/2, Bcl2, Bax and cytochrome c and the expression of genes influencing Ca2+ homeostasis were assessed. In remifentanil-administered rat hearts, regardless of the timing and duration of administration, infarct size was consistently reduced compared to I/R only rats. Remifentanil improved expression of ERK1/2 and anti-apoptotic protein Bcl2, and expression of sarcoplasmic reticulum genes which were significantly reduced in the I/R rats only. Remifentanil reduced expression of pro-apoptotic protein, Bax and cytochrome c. These suggested that remifentanil produced cardioprotective effect by preserving the expression of proteins involved in anti-apoptotic pathways, and the expression of sarcoplasmic reticulum genes in I/R rat heart, regardless of the timing of administration.

Peri-operative oral triiodothyronine replacement therapy to prevent postoperative low triiodothyronine state following valvular heart surgery.

This study evaluated the effect of oral triiodothyronine (T(3)) replacement therapy, starting on the day of the surgery, on thyroid hormone concentrations and clinical outcome in high-risk patients undergoing valvular heart surgery. Fifty patients were randomly allocated to either T(3) or placebo. In the treatment (T(3)) group patients received 20 microg of oral or nasogastric T(3) every 12 h starting just before induction of anaesthesia and until the first day after surgery. T(3) concentrations were significantly higher in the T(3) group than the placebo group from 1 to 36 h after removal of the aortic cross clamp. The number of patients requiring vasopressin after discontinuing cardiopulmonary bypass was significantly greater in the placebo group than the T(3) group. Significantly fewer patients required vasopressors in the T(3) group on the first day after surgery.