Priming Fluid Research Articles

Monitoring relative blood volume changes during hemodialysis: Impact of the priming procedure.

The monitoring of relative blood volume (RBV) changes during hemodialysis is increasingly used to evaluate the effect of dialyzer ultrafiltration on intravascular volume to guide the removal of excess fluid in a manner that maintains hemodynamic stability of the patient. RBV monitoring is typically based on an optical or acoustic sensor placed in the arterial blood line that measures a marker of hemoconcentration, such as hematocrit, hemoglobin, or total blood protein. However, the accuracy of RBV monitors and the impact of their clinical use remain the subject of ongoing debate. Here, we show that, depending on the procedure of filling the extracorporeal circuit with the patient's blood at the beginning of the dialysis session, theindications of an RBV monitor may be misleading as to the actual changes of the intravascular volume. When the blood is first pumped into the dialyzer, the priming fluid (saline) that fills the circuit may be either infused into the patient or disposed of to a drain bag. In the latter case, the intravascular volume is suddenly reduced, which is not accounted for by RBV monitors that track only the subsequent reductions in blood volume due to dialyzer ultrafiltration. Weanalyzed this general aspect of RBV monitoring using model-based simulations and showed quantitatively how RBV changes calculated using hematocrit differ depending on the priming procedure.

Percentage of hematocrit decrease after the initiation of cardiopulmonary bypass-clinical implications and affecting factors.

Decrease of patient's hematocrit level is a natural process which occurs during the initiation of cardiopulmonary bypass. To some extent it is a beneficial occurrence, but excessive hematocrit decrease can lead to many complications and increase patient's demand for blood transfusion. In this study authors investigated the causes and clinical implications of ≥30% hematocrit decrease after the initiation of cardiopulmonary bypass. Retrospective analysis of 172 patients undergoing elective cardiac surgery procedures was conducted. It was concluded that 30% or greater hematocrit decrease (comparing to preoperative level) after the initiation of cardiopulmonary bypass, is associated with an increased demand for blood transfusion. The most important factors influencing hematocrit decrease after the initiation of cardiopulmonary bypass proved to be: lower BMI, female gender, more advanced age and the usage of priming fluid of higher volume and lower osmolality.

Dextran- Versus Crystalloid-Based Prime in Cardiac Surgery: A Prospective Randomized Pilot Study

The optimum priming fluid for the cardiopulmonary bypass (CPB) circuit is still debated. We compared a new hyperoncotic priming solution containing dextran 40, which has an electrolyte composition that mimics extracellular fluid, with a standard crystalloid-based prime. Eighty cardiac surgery patients were included in this double-blind, randomized, single-center study. Patients were randomized to either a dextran-based prime or a crystalloid prime containing Ringer's acetate and mannitol. The primary end point was colloid oncotic pressure in serum during CPB. Secondary end points included fluid balance, bleeding and transfusion requirements, pulmonary function, hemolysis, systemic inflammation, and markers of renal, hepatic, myocardial, and brain injury. Blood samples were collected before, during, and after CPB. Colloid oncotic pressure was higher in the dextran group than in the crystalloid prime group during CPB (18.8 ± 2.9 versus 16.4 ± 2.9 mm Hg; P < .001) and 10 minutes after CPB (19.2 ± 2.7 versus 16.8 ± 2.9 mm Hg; P < .001). Patients in the dextran group required less intravenous fluid during CPB (1090 ± 499 versus 1437 ± 543 mL; P= .004) and net fluid balance was less positive 12 hours after surgery (1431 ± 741 versus 1901 ± 922 mL; P= .014). Plasma-free hemoglobin was significantly lower in the dextran group 2 hours after CPB (0.18 ± 0.11 versus 0.41 ± 0.33; P= .001). There were no significant differences in bleeding, transfusion requirements, organ function, systemic inflammation, or brain and myocardial injury markers between groups at any time point. Our results suggest that a hyperoncotic dextran-based priming solution preserves intraoperative colloid oncotic pressure compared with crystalloid prime. Larger studies with clinically valid end points are necessary to evaluate hyperoncotic prime solutions further.

Enhanced recovery after cardiac surgery: fluid balance and incidence of acute kidney injury

Introduction Enhanced Recovery after Cardiac Surgery (ERACS) pathways can increase patient satisfaction, reduce the length of hospital stay and stay in the intensive care unit. The reported incidence of acute kidney injury (AKI) after cardiac surgery varies from 2.5% to 40% and is associated with an increased 30-day mortality¹. We examined the effect of ERACS on the total amount of fluid administered and the incidence of AKI. Methods We retrospectively analyzed prospectively collected outcome data of patients undergoing cardiac surgery enrolled in the ERAS pathway (n = 107) compared to a historical standard care group (n = 173). The ERAS pathway included pre-operative patient education, multimodal pain management to minimize opioid usage, carbohydrate loading 2-4hrs before induction of anesthesia, tight glucose control, early postoperative invasive access and chest tube removal, early extubation, and early mobilization. Intraoperatively, 500mL of the cardiopulmonary bypass (CBP) priming fluid was replaced with albumin 5% and the patients received 250mL albumin 5% before initiation and 250mL after separation from CBP. Crystalloid boli were administered in the intensie care unit (ICU) for clinical signs of hypovolemia, increasing pressor requirements or worsening metabolic acidosis. The standard care group was treated per preexisting institutional guidelines. AKI was defined using modified KDIGO (Kidney Disease Improving Global Outcomes) criteria, patients with pre-existing renal injury were excluded. Data were compared using univariate analysis: parametric and non-parametric data were analyzed with Student's t-test and Wilcoxon rank-sum test, respectively. A p-value of less than 0.05 was considered statistically significant. Results The mean (SD) creatinine pre-operatively, at discharge, and the peak creatinine were not different between the ERACS and the standard care group (table). Less fluid was administered in the ERACS group, but the total fluid balance was not different. No significant difference exists between the occurrence of AKI between those groups; no patient developed AKI worse than KDIGO stage 1 (modified). Discussion Although the ERACS patients received less fluid than the standard care group during the hospital stay, the incidence of AKI did not differ, nor did the serum creatinine at discharge between both groups. A restrictive fluid management with intraoperative albumin administration does not increase the incidence of acute kidney injury for patients in the ERACS pathway.

Extracorporeal rewarming from experimental hypothermia: Effects of hydroxyethyl starch versus saline priming on fluid balance and blood flow distribution.

What is the central question of this study? Mortality in accidental hypothermia patients rewarmed by extracorporeal circulation remains high. Knowledge concerning optimal fluid additions for extracorporeal rewarming is lacking, with no apparent consensus. Does colloid versus crystalloid priming have different effects on fluid balance and blood flow distribution during extracorporeal rewarming? What is the main finding and its importance? In our rat model of extracorporeal rewarming from hypothermic cardiac arrest, hydroxyethyl starch generates less tissue oedema and increases circulating blood volume and organ blood flow, compared with saline. The composition of fluid additions appears to be important during extracorporeal rewarming from hypothermia. Rewarming by extracorporeal circulation (ECC) is the recommended treatment for accidental hypothermia patients with cardiac instability. Hypothermia, along with initiation of ECC, introduces major changes in fluid homeostasis and blood flow. Scientific data to recommend best practice use of ECC for rewarming these patients is lacking, and no current guidelines exist concerning the choice of priming fluid for the extracorporeal circuit. The primary aim of this study was to compare the effects of different fluid protocols on fluid balance and blood flow distribution during rewarming from deep hypothermic cardiac arrest. Sixteen anaesthetized rats were cooled to deep hypothermic cardiac arrest and rewarmed by ECC. During cooling, rats were equally randomized into two groups: an extracorporeal circuit primed with saline or primed with hydroxyethyl starch (HES). Calculations of plasma volume (PV), circulating blood volume (CBV), organ blood flow, total tissue water content, global O2 delivery and consumption were made. During and after rewarming, the pump flow rate, mean arterial pressure, PV and CBV were significantly higher in HES-treated compared with saline-treated rats. After rewarming, the HES group had significantly increased global O2 delivery and blood flow to the brain and kidneys compared with the saline group. Rats in the saline group demonstrated a significantly higher total tissue water content in the kidneys, skeletal muscle and lung. Compared with crystalloid priming, the use of an iso-oncotic colloid prime generates less tissue oedema and increases PV, CBV and organ blood flow during ECC rewarming. The composition of fluid additions appears to be an important factor during ECC rewarming from hypothermia.

Dysfunctional Closed Chest Drainage - Common Causative Factors and Recommendations for Prevention.

IntroductionDysfunctional closed chest drainage unit (CDU) dysfunction is a common but serious clinical problem associated with tube thoracostomy and results in a significant rise in morbidity, prolonged hospital stays, and increased economic burden. This observational study examines the proximate factors of closed CDU dysfunction in addition to their relative frequency. Based on our findings, we suggest logical recommendations for preventing the factors that contribute to closed chest drainage unit dysfunction.MethodThe study target population consists of all those individuals who had experienced tube thoracostomy for any pathology related to the chest cavity treated in the Department of Thoracic Surgery, Nishter Medical University, Multan, Pakistan, from February 2015 to January 2017. The study population was not restricted by age or gender. Of the 727 examined cases, only those patients who had experienced tube thoracostomy and had significant failure in draining the pleural collection were included in the study. Detailed histories were collected, and thorough physical examinations were carried out for each participant. Chest x-rays and, if needed, computed tomography (CT) scans were obtained to properly examine the placement of the chest tubes and detect the causative factor of the closed CDU dysfunction.ResultsA total of 139 cases were included in the study. The most common cause of closed CDU dysfunction was the use of the wrong CDU connection (n = 24, 17.3%). Other common problems included inadequate prime fluid use, loose connections, kinked tubes, and overly full bottles.ConclusionClosed CDU dysfunction may be prevented by adopting and following proper protocols for tube thoracostomy.

An evaluation of four modes of low-dose anticoagulation during intermittent haemodialysis

IntroductionIntensive care participants that need dialysis frequently suffer from increased risk of bleeding. Standard intermittent haemodialysis (SHD) includes anticoagulation to avoid clotting of the dialysis system. The aim of this study was to clarify which of four different low-dose anticoagulant modes was preferable in reducing the exposure to i.v. unfractionated heparin (heparin) and maintaining patency of the dialysis circuit.MethodsTwenty-three patients on SHD were included to perform haemodialysis with four modes of low-dose anticoagulation. For comparative analyses, patients served as their own control. Haemodialysis with a single bolus of tinzaparin at the start was compared to haemodialysis initiated without i.v. heparin but priming with (1) heparin in saline (H), (2) heparin and albumin in saline (HA), (3) heparin and albumin in combination with a citrate-containing dialysate (HAC), (4) saline and usinga heparin-coated filters (Evodial®). The priming fluid was discarded before dialysis started. Blood samples were collected at 0, 30 and 180 min during haemodialysis. Smaller bolus doses of heparin (500 Units/dose) were allowed during the modes to avoid interruption by clotting.FindingsThe mean activated partial thromboplastin (APTT) time as well as the doses of anticoagulation administered was highest with SHD and least with HAC and Evodial®. Mode H versus SHD had the highest rate of prematurely interrupted dialyses (33%, p = 0.008). The urea reduction rate was less with Evodial® vs. SHD (p < 0.01). One hypersensitivity reaction occurred with Evodial®. Changes in blood cell concentrations and triglycerides differed between the modes.DiscussionIf intermittent haemodialysis is necessary in patients at risk of bleeding, anticoagulation using HAC and Evodial® appeared most preferable with least administration of heparin, lowest APTT increase and lowest risk for prematurely clotted dialyzers in contrast to the least plausible H mode.

Comparison of Albumin, Hydroxyethyl Starch and Ringer Lactate Solution as Priming Fluid for Cardiopulmonary Bypass in Paediatric Cardiac Surgery.

In paediatric cardiac surgery, there is still not any information with regard to the best choice of priming fluids for Cardiopulmonary Bypass (CPB). Albumin, Hydroxyethyl Starch (HES) & ringer lactate are equally used, but each has its advantages & disadvantages. Albumin & HES had better fluid balance which affect outcome in paediatric cardiac surgery significantly. To compare priming solution containing albumin, hydroxyethyl starch and ringer lactate during elective open-heart surgery in paediatrics aged up to 3 years. All patients were managed by standardized institution protocol and were randomly distributed into three groups based on the priming solution which is used in the CPB Circuit and having 35 patients in each group. Group A: Receive albumin 10 ml/kg in priming solution, Group B: Receive Hydroxyethyl starch (HES130/0.4) 6% 20ml/kg in priming solution, Group C: Receive ringer lactate priming solution. Primary outcome variable included perioperative haemoglobin, total protein, colloid osmotic pressure, platelets, fluid balance, urine output, post-operative blood loss, blood products usage, renal & liver function, extubation time, ICU stay & outcome. Patients receiving albumin had higher perioperative platelet count, total protein level & colloid osmotic pressure, lesser post-operative blood loss & blood products requirement. Patients receiving HES had lower level of platelets postoperatively than ringer lactate group but not associated with increase blood loss. HES did not affect renal function & haemostasis in this dose. Patients receiving ringer lactate had positive fluid balance intraoperatively. All three groups have similar effect on renal & liver function, urine output, time to extubation, ICU stay & outcome. We conclude that albumin is expensive but better prime as maintain haemostasis, colloid oncotic pressure & reduced blood product requirement. HES will not hamper haemostasis & renal function in lower dose & better than crystalloid as maintain negative fluid balance. Patient outcome & ICU stay was similarly affected by priming solutions.

Impact of 6 % hydroxyethyl starch (HES) 130/0.4 on the correlation between standard laboratory tests and thromboelastography (TEG®) after cardiopulmonary bypass

BackgroundHydroxyethyl starches (HES) affect the results of thromboelastography (TEG®). We sought to determine whether using HES rather than crystalloids for cardiopulmonary bypass (CPB) prime and intraoperative fluid therapy changes the TEG cutoff values best identifying patients with a low platelet count or a low fibrinogen level after CPB. MethodsData from 96 patients who had on-pump cardiac surgery, a TEG® (kaolin-heparinase) and standard investigations of blood clotting performed after separation from CPB and protamine administration were retrospectively reviewed. Patients were assigned to the HES or crystalloid group according to whether balanced 6% HES 130/0.4 or balanced crystalloids were used for intraoperative fluid therapy and pump prime. Mutlivariable linear regression models with computation of the standardized regression coefficients were used to identify independent associations between the four main TEG parameters (R time, alpha angle, K time and MA) and the type of fluid used, the INR, the aPTT, the fibrinogen level and the platelet count. Receiver-operating-characteristic curves were used to assess the effect of HES on the ability of TEG parameters to identify patients with a platelet count<80.000μl-1 or a fibrinogen level<1.5 gr l-1 and on the cutoff values best identifying these patients. ResultsThe type of fluid used significantly affected the MA (P<0.001), the K time (P<0.001) and the alpha angle (P<0.001) regardless of the results of the standard clotting tests. According to standardized ß regression coefficients the platelet count and the type of fluid used were stronger predictors of the MA, the alpha angle and the K time than the fibrinogen level. MA better predicted platelets<80.000μl-1 than K time and alpha angle (P=0.023). The best cutoff value of MA identifying patients with platelets<80.000μl-1 was 62mm in the crystalloid group and 53mm in the HES group. MA, K time and alpha angle were poor predictors of the postoperative fibrinogen level. ConclusionHES significantly changes the cutoff value of TEG® MA best identifying patients<80.000μl-1 after on-pump cardiac surgery.

Can topical administration of tranexamic acid be a good adjuvant to the intravenous route for decreasing postoperative seizure incidence? A double blinded randomized study

Background Antifibrinolytic therapy has become a mainstay in complex cardiac surgical procedures for decreasing bleeding and minimizing transfusion requirements. Tranexamic acid (TA) is an antifibrinolytic agent that can be used both systemically and topically. Current studies and case series reports mention an increased incidence of seizures after administration of high doses of TA (60-260 mg/kg body weight). Thus, we hypothesize that adding a topical dose of TA to a small dose intravenously could reduce postoperative bleeding in patients who have undergone cardiac surgery with subsequent decrease in the overall complications associated with this drug, mainly seizures. Materials and methods A total of 120 patients were randomly allocated to two groups, the intravenous TA group (group I) and the topical and intravenous TA group (group II), with 60 patients in each. Every patient in group I received an initial bolus dose of TA consisting of a bolus of 50 mg/kg body weight at the beginning and at the end of cardiopulmonary bypass (CPB), and 100 mg/100 ml priming volume was added to the priming fluid of the CPB system. In group II every patient received an initial bolus dose of TA at 30 mg/kg infused over 15 min followed by a 16 mg/kg/h infusion until chest closure with a 2 mg/kg load within the pump prime; in addition, before sternotomy closure, patients received another 2 g of TA diluted in 500 ml of warm saline (37°C), which was poured into the pericardial cavity. Results Hemoglobin concentration, hematocrit value, platelet count, international normalized ratio, bleeding time, activated partial thromboplastin time, total volume of blood loss, and total volume of blood transfused into the patients showed no significant differences between the two groups throughout the study. In contrast, prothrombin time and activated clotting time were significantly higher in group II when compared with group I at 2 h postoperatively. Seizure incidence was significantly lower in group II when compared with group I. However, the number of re-explored cases was insignificant when the two groups were compared. Conclusion Topical application of TA in addition to a small intravenous dose in patients undergoing open cardiac surgery using CPB reduces perioperative blood loss and transfusion in those patients to the same extent as sole large intravenous dose with less incidence of seizures.

Influence of Two Colloidal Extracorporeal Primes on Coagulation of Cardiac Surgical Patients: A Prospectively Randomized Open-Label Pilot Trial

The search for the ideal priming fluid continues as more evidence is discovered about side effects of volume expanders. With the availability of modern, balanced hydroxyethyl starch (HES) solutions with less side effects than former HES solutions, we considered to replace our gelatin- (modified gelatin) based extracorporeal circuit prime for a HES (130/.42) prime. Therefore, we studied the influence of two colloidal priming fluids on postoperative coagulation in patients undergoing cardiac surgery. The primary endpoint was to compare clot formation time between the HES group and the gelatin group with rotational thromboelastometry (ROTEM). Additionally we compared colloid osmotic pressure and fluid balance of both groups. Forty patients, undergoing elective first time coronary artery bypass grafting or single-valve surgery, were included in this prospectively randomized open-label pilot study. Laboratory data and ROTEM data were collected and analyzed for differences between the two groups. ROTEM data show significantly more prolongation in Extem clot formation time and significant more decrease in Extem alpha in the HES group. Fibtem maximum clot firmness was significantly smaller in the HES group; this was consistent with fibrinogen concentration measurement, which decreased more in the HES group than in the gelatin group and recovered more over time in the gelatin group. We found no significant difference in colloid osmotic pressure between the groups. In this trial, HES (130/.42) impairs coagulation significantly more compared with gelatin. These differences in influence on coagulation did not lead to a difference in blood loss or fluid balance, so clinical relevance could not be proven.

The effect of intraoperative 6% balanced hydroxyethyl starch (130/0.4) during cardiac surgery on transfusion requirements.

To compare transfusion requirements in adult cardiac surgery patients when balanced hydroxyethyl starches (HES) (130/0.4) or balanced crystalloids is used for pump prime and intraoperative fluid therapy. Data were obtained retrospectively from medical records and perfusion charts. Matching based on propensity scores was used to adjust for potential confounders. A university hospital. Adult patients undergoing cardiac surgery with the use of cardiopulmonary bypass. Allocation to one of the study groups according to whether balanced HES or balanced crystalloids was used for pump prime and intraoperative fluid therapy. 240 propensity-matched patients were retained for final analyses. Forty-eight patients (40%) of the colloid group and 28 patients (23.3%) of the crystalloid group received blood products, with an odd ratio (95% CI) of 2.1(1.2-3.8 (P=0.009). After bypass HES patients had lower hemoglobin levels (8.4 [1.3] gr/dL vs 9.6 [2] gr/dL; P<0.001) and a higher cumulative chest drain output after 3 hours (180 [210] mL vs 140 [100] mL, P<0.001]. Heparinase thromboelastogram (TEG®) showed longer K times (2.5[1.1] vs 1.6[0.8], P<0.001) and lower maximal amplitudes (55.1[12.5] vs 63.4[9.8], P=0.008). HES patients required more transfusions, owing to greater hemodilution, HES-induced clotting disturbances, and bleeding.

72 hours standby time of wet-primed cardiopulmonary bypass circuits: a microbiological quality assurance study.

In a microbiological sample study of 15 wet-primed cardiopulmonary bypass circuits in standby mode for 72 hours under regular clinical conditions, no contamination of the priming fluid or the connectors could be detected. Hand contact surfaces of the machines demonstrated environmental microorganisms. These findings indicate the safe use of primed cardiopulmonary bypass circuits in standby mode for 72 hours. A surface disinfection of hand contact surfaces immediately before use is recommended.

Coronary artery bypass grafting in 2 thrombophilic patients with protein s deficiency.

In this report, we review 2 cases of coronary revascularization in patients with a diagnosis of coronary artery disease and preoperative protein S deficiency, an established hypercoagulable condition. In an attempt to normalize protein S levels, fresh frozen plasma was used as the priming fluid for the cardiopulmonary bypass circuit before the initiation of extracorporeal circulation. On the basis of a low risk of bleeding and the theoretical risk of thrombosis, neither patient received intraoperative antifibrinolytic treatment nor did they develop perioperative thrombotic complications.

Does Removing Mannitol and Voluven from the Priming Fluid of the Cardiopulmonary Bypass Circuit Have Clinical Effects?

The Auckland Hospital cardiothoracic unit recently removed Mannitol and Voluven from its Plasma-lyte-based cardiopulmonary bypass (CPB) priming fluid. Like with any change to practice, a comprehensive audit should be performed to identify positive or negative effects. The aim of this retrospective analysis was to investigate the effect of changing the CPB prime constituents on fluid balance and clinical outcome parameters. Clinical records were reviewed for 100 consecutive patients undergoing primary, isolated coronary artery bypass grafting (CABG), 50 patients before the prime change and 50 after. All data were collated into a central database for analysis. Mean arterial pressure while on bypass was higher in the new prime group (61.5 mmHg versus 57.5 mmHg, p = .002). There was no significant difference in hematocrit, hemoglobin, serum sodium, serum potassium, or creatinine postoperatively between groups. In regard to important outcomes such as postoperative weight and fluid balance, time on ventilation, length of stay in the intensive care unit (ICU) or hospital, and mortality, there were no significant differences. Interestingly, new prime group spent a smaller proportion of their time in the ICU on mechanical ventilation (23% versus 36%, p = .022). Mannitol and Voluven, like with all drugs, carry their own potential adverse effects. This study demonstrates that removing Mannitol and Voluven from priming fluid did not have any detrimental effect on electrolytes, fluid status, and other important outcomes in this consecutive series of patients having primary isolated CABG surgery. The risk–benefit balance combined with the obvious economic benefit clearly favors removing Mannitol and Voluven from priming fluids.

Improvement of tensile shear strength and wood failure percentage of 1C PUR bonded wooden joints at wet stage by means of DMF priming

Tensile shear tests according to EN 302-1 for load-bearing timber structures were performed on European beech wood (Fagus sylvatica L.) and Douglas fir [Pseudotsuga menziesii (Mirb.) Franco] bonded by means of a one-component polyurethane adhesive (1C PUR). Results reveal a substantial loss of tensile shear strength (TSS) and wood failure percentage (WFP) at the wet stage compared to the dry stage. As can be seen from microscopic images, this is accompanied by a loss of adhesion at the boundary layer. Therefore, the aim of this work was to find a priming fluid that improves the load transmission between adhesive and adherend at the wet stage without introducing formaldehyde into the gluing process. A substantial improvement of TSS and WFP was achieved by means of the hygroscopic organic solvent N,N-dimethylformamide (DMF). In addition, contact angle measurements were carried out, revealing that DMF heavily enhances the wettability of the joining surface. Furthermore, it was attempted to integrate the outcomes into the swelling strain model stated by Frihart in 2009. By way of comparison a hydroxymethylated resorcinol coupling agent, a mixture of diphenylmethane-4,4′-diisocyanate isomers and water were also tested as priming fluids. The data confirm that TSS and WFP of 1C PUR bonded wooden joints do not correlate, whilst WFP is mostly not normally (at wet stage often bimodally) distributed.

Effect of 6% Hydroxyethyl Starch 130/0.4 as a Priming Solution on Coagulation and Inflammation Following Complex Heart Surgery

PurposeProlonged duration of cardiopulmonary bypass aggravates the degree of inflammation and coagulopathy. We investigated the influence of 6% hydroxyethyl starch (HES) 130/0.4 on coagulation and inflammation compared with albumin when used for both cardiopulmonary bypass priming and perioperative fluid therapy in patients undergoing complex valvular heart surgery.Materials and MethodsFifty four patients were randomly allocated into albumin-HES, albumin-nonHES, and HES-HES groups. The cardiopulmonary bypass circuit was primed with 5% albumin in the albumin-HES and albumin-nonHES group, and with HES in the HES-HES group. As perioperative fluid, only plasmalyte was used in the albumin-nonHES group whereas HES was used up to 20 mL/kg in the albumin-HES and albumin-HES group. Serial assessments of coagulation profiles using the rotational thromboelastometry and inflammatory markers (tissue necrosis factor-α, interleukin-6, and interleukin-8) were performed.ResultsPatients' characteristics and the duration of cardiopulmonary bypass (albumin-HES; 137±34 min, HES-HES; 136±47 min, albumin-nonHES; 132±39 min) were all similar among the groups. Postoperative coagulation profiles demonstrated sporadic increases in clot formation time and coagulation time, without any differences in the actual amount of perioperative bleeding and transfusion requirements among the groups. Also, inflammatory markers showed significant activation after cardiopulmonary bypass without any differences among the groups.ConclusionEven in the presence of prolonged duration of cardiopulmonary bypass, HES seemed to yield similar influence on the ensuing coagulopathy and inflammatory response when used for priming and perioperative fluid therapy following complex valvular heart surgery compared with conventional fluid regimen including albumin and plasmalyte.

Myocardial protection of Shenmai injection in patients subject to beating-heart surgery

Objective To evaluate the myocardial protective effects of Shenmai injection in patients udnergoing cardiopul-monary bypass (CPB) surgery on beating-heart.Methods Sixty patients with rheumatic heart disease preparing for mitral valve replacement were randomly divided into two groups:control group (group A,n =30) and experimental group (group B,n =30).The patients in group B were given Shenmai injection 0.6 ml/kg in circuit priming fluids,and those in group A were given equal volume of normal saline.Blood samples were collected before surgery (T1),at 30 min of CPB (T2),at the end of CPB (T3) and operation (T4),24 h after operation (T5),and 72 h after operation (T6) for assessment of lactate dehydrogenase (LDH),CK-MB,cardiac Troponin T (cTnT),superoxide dismutase (SOD) and malondialdehyde (MDA).Results (1) The levels of LDH were significantly lower in group B than in group A at T3 to T6 [(258.55 ± 21.83) U/L vs.(345.12 ± 25.28) U/L,(306.40 ± 26.11) U/L vs.(396.36 ± 22.66) U/L,(335.62 ± 26.72) U/L vs.(415.74 ± 39.56) U/L,(380.00 ± 31.53) U/L vs.(435.45 ±41.39) U/L] (P ＜0.05).The levels of CK-MB were significantly lower in group B than in group A at T2 to T5 [(33.70 ± 12.60) U/L vs.(42.31 ± 11.03) U/L,(48.91 ± 12.30) U/L vs.(78.81 ±15.03) U/L,(55.82±15.28) U/Lvs.(90.76±20.14) U/L,(73.09 ±24.34) U/Lvs.(109.05 ±24.33) U/L] (P ＜0.05).The levels of cTnT were significantly lower in group B than in group AatT2 to T6 [(0.89 ± 0.27) U/Lvs.(2.61 ±0.25) U/L,(5.49±1.79) U/Lvs.(11.48±2.41) U/L,(8.31 ±2.44) U/L vs.(18.34 ±3.76) U/L,(17.91 ±3.42) U/L vs.(27.05 ±4.24) U/L,(5.10 ± 1.42) U/L vs.(11.19 ±2.80) U/L] (P＜0.05).(2) The levels of SOD were significantly higher in group B than in group A at T2 to T6[(68.69 ±7.26) U/L vs.(55.22 ±7.30) U/L,(54.28 ±7.94) U/L vs.(35.11 ±6.61) U/L,(44.03 ±6.17) U/L vs.(25.41 ±3.98) U/L,(53.93 ±6.76) U/L vs.(41.60 ± 3.79) U/L,(64.27 ± 7.13) U/L vs.(50.02 ± 4.45) U/L] (P ＜ 0.05).The levels of MDA were significantly lower in group B than in group A at T2 to T6 [(4.38 ± 0.54) μmol/L vs.(6.97 ± 0.76) μmol/L,(6.13 ±0.65) μmol/L vs.(8.59 ±0.96) μmol/L,(8.02 ±0.95) μmol/L vs.(10.28 ±0.58) μmol/L,(5.78 ±0.63) μmol/L vs.(8.55 ±0.57) μmol/L,(4.53 ±0.51) μmol/L vs.(6.62 ± 0.55) μmol/L] (P ＜ 0.05).Conclusion Shenmai injection offers protective effect on myocardial ischemia-reperfusion injury during beating heart surgery,by increasing the activity of SOD and reducing the production of myocardial enzyme leak and MDA. Key words: Shenmai injection; Cardiopulmonary bypass ; Myocardial protection; Oxygen free radical

Wet-priming extracorporeal membrane oxygenation device maintains sterility for up to 35 days of follow-up

In emergency cases, rapid extracorporeal membrane oxygenation (ECMO) device initialization is able to drastically reduce the incidence of patient morbidity and/or mortality. Pre-assembled and ready-to-use ECMO circuits might save up to 30-60 critical minutes in patient management. Six ECMO circuits (Oxygenator D905 EOS with REVOLUTION™ pump and Sorin PTS) were assembled in the operating room in standard conditions and then placed at 37°C for 35 days in order to evaluate possible contamination and ingrowth of micro-organisms. Every 7 days after ECMO circuit assembly and wet-priming, samples of priming fluid were analyzed to verify the presence/absence of possible common contaminants (Enterobacteriaceae, Staphylococcus aureus and fungi). Moreover, two supplementary circuits, used as positive controls, were deliberately inoculated with a known concentration of a Escherichia coli strain and prime samplings carried out at different time-points to determine bacterial growth rate. Sterility was maintained in the ECMO circuits for up to 35 days.

Comparison of the effects of hydroxy ethyl starch 6% versus gelatin as replacement of prime fluid during coronary artery bypass graft

Isfahan University of Medical Sciences, Department of Anaesthesiology and Intensive Care, Isfahan, Iran, Islamic Republic of