Acute Normovolemic Hemodilution Group Research Articles

Effects of acute normovolemic hemodilution on healing of gastric anastomosis in rats.

PurposeAcute normovolemic hemodilution (ANH) is an autologous transfusion method, using blood collected during surgery, to reduce the need for allogeneic blood transfusion. ANH is controversial because it may lead to various complications. Among the possible complications, anastomotic leakage is one that would have a significant effect on the operation outcome. However, the relationship between ANH and anastomotic site healing requires additional research. Therefore, we conducted this prospective study of ANH, comparing it with standard intraoperative management, undergoing gastric anastomosis in rats.MethodsSixteen Sprague-Dawley rats were randomly assigned to three groups: group A, surgery with ANH; group N, surgery with standard intraoperative management; and group C, sham surgery with standard intraoperative management. ANH was performed in group A animals by, removing 5.8–6.6 mL of blood and replacing it with 3 times as much crystalloid. All rats were enthanized on postoperative day 6, and histopathologic analyses were performed.ResultsThe mean hematocrit values, after hemodilution were 22.0% (range, 18.0%–29.0%), group A; 33.0% (29.0%–35.0%), group N; and 32.5% (29.0%–34.0%), group C. There were significant differences between groups A and N (P = 0.019, P = 0.009, P = 0.004, P = 0.039, and P = 0.027), and between groups N and C (P = 0.006, P = 0.027, P = 0.04, P = 0.008, and P = 0.009) with respect to inflammatory cell numbers, neovascularization, fibroblast numbers, edema and necrosis, respectively; there were no differences between groups A and N.ConclusionIn rat model, anastomotic complications did not increase in the ANH group, compared with the standard intraoperative management group.

Evaluation of acute normovolemic hemodilution in patients undergoing intracranial meningioma resection: A quasi-experimental trial.

The aim of this study was to evaluate the safety of acute normovolemic hemodilution (ANH) for patients undergoing intracranial meningioma resection.Eighty patients (aged 48–65 years) with American Society of Anesthesiologists physical status I–II undergoing intracranial meningioma resection were included in this prospective observational study. The patients were randomly divided into group A (ANH group), which underwent a combination of ANH and intraoperative cell salvage (ICS), and group B (control group), which underwent ICS alone. The study parameters were recorded as baseline values before blood drainage (T0), after blood drainage (T1), and before (T2) and after (T3) retransfusion in group A. Whereas in group B, the same parameters were measured 10 minutes after anesthesia induction (T0), before surgery (T1), and before (T2) and after (T3) transfusion of autologous blood.When intraoperative blood loss was <2000 mL, the mean volume of homologous blood transfused in group A patients was 100.8 ± 82.3 mL, compared with the 190.0 ± 91.8 mL in group B. Reduction in homologous blood used in group A was statistically significant (P < .05). In group B, 15.1% patients received homologous blood, whereas only 5.9% patients received homologous blood in group A. The difference in heart rate between both groups at different time points was statistically nonsignificant (P > .05). The mean hemoglobin and hematocrit levels at T1 and T2 in group A were lower than in group B (P < .05). The prothrombin time and activated partial thromboplastin time in both groups were prolonged significantly after T2 (all P < .05), but were all within normal range. There were no significant differences in postoperative hospital stay, mortality, and postoperative infection between the 2 groups.For patients undergoing excision of intracranial meningioma, ANH is an effective procedure to reduce the need for allogeneic transfusions.

The application of acute normovolemic hemodilution in spinal tumor operation

Objective To evaluate the applied value of acute normovolemic hemodilution (ANH) in massive spinal tumor surgery bleeding. Methods 100 patients undergoing operation of spinal tumor removal under general anesthesia were selected-52 males and 48 females, with age ranging from 39 to 60 years old. Participants with American Society of Anesthesiologist (ASA) Ⅰ-Ⅱ randomly divided into two groups: ANH group (group A) and control group (group C), with 50 patients in each. Group A received ANH under general anesthesia, targeting 32% hematocrit (Hct). During exsanguination, blood was diluted with identical volume of hydroxyethyl starch 130/0.4 and sodium chloride injection. Group C was not given ANH. The dynamic changes of fast thrombelastogram (r-TEG) indicators [coagulation factor activity (ACT), K, Angle, maximum aggregation (MA), MA 30 min thrombosis and fibrinolysis percentage (EPL/LY30)] were recorded at four time points: before ANH (T1), 10 min after ANH (T2), after tumors were removed and bleeding stopped (T3) and when ANH autologous blood transfusion was completed (T4), respectively. Results At T1 and T2, r-TEG indicators in groups A and C had no significant change, and the difference between group A and group C showed no statistically significant difference. In group A, the ACT values at T1, T3 and T4 were (101.0±8.0), (131.0±10.0) and (122.0±11.0) respectively, with the difference being statistically significant (P=0.001); the K values were (1.5±0.3), (2.4±0.1) and (1.9±0.2), with the difference being statistically significant (P=0.001); the Angle values were (68.4±2.2), (63.0±2.1) and (70.0±5.0), with the difference being statistically significant (P=0.001); the MA values were (56.1±2.0), (48.5±2.1) and (49.6±1.2), with the difference being statistically significant (P=0.001). In group C at T1, T3 and T4, the ATC values were (102.0±7.6), (130.0±11.1) and (135.0±10.5), with the difference being statistically significant (P=0.001); the K values were (1.50±0.20), (2.30±0.15) and (2.53±0.16), with the difference being statistically significant (P=0.001); the Angle values were (68.5±2.1), (63.5±2.6) and (60.1±2.5), with the difference being statistically significant (P=0.001); the MA values were (58.2±3.1), (48.6±2.0) and (43.4±2.5), with the difference being statistically significant (P=0.001). Introperative blood loss, transfusion volume, operative time, and postoperative drainage volume in group C were significantly increased as compared with those in group A. Conclusion ANH can effectively improve patients’ blood coagulation function, save blood resources, reduce allogeneic erythrocytes transfusions, shorten operative time, and decrease chances of infections. As such, it is reasonable to promote the application of ANH in spinal tumor removal surgery. Key words: Acute normovolemic hemodilution; Spinal tumor; Thrombelastography

The effectiveness of acute normolvolemic hemodilution and autologous prime on intraoperative blood management during cardiac surgery.

Intraoperative blood management during cardiac surgery is a multifaceted process incorporating various interventions directed at optimizing oxygen delivery and enhancing hemostasis. The purpose of this study was to evaluate the effects of acute normovolemic hemodilution (ANH) and autologous priming (AP) on preserving the hematocrit during cardiopulmonary bypass (CPB). Case records from a national registry of adult patients who underwent cardiac surgery between January and October 2016 were reviewed. Groups were determined as follows: ANH, AP, ANH+AP or Neither. Primary endpoint was first the hematocrit on CPB with secondary endpoints of hematocrit drift and red blood cell (RBC) transfusion rate. Eighteen thousand and twenty-four (18,024) consecutive patients were reviewed. The first CPB hematocrit was lowest in the ANH group (26.5%±4.4%) and highest in ANH+AP patients (27.5%±4.8%) (p<0.001). The change in hematocrit was greatest in the ANH group (8.3%±3.9%) compared to both the AP (6.4%±3.8%) and ANH+AP (6.9%±4.1%) groups (p<0.001). Intraoperative RBC transfusions were as follows: ANH 26 (7.8%), AP 2,531 (20.0%), ANH+AP 287 (10.3%) and Neither 592 (26.7%) (p<0.001). Regression results show that the use of ANH will result in the greatest decline in hematocrit values. When combined with AP, higher hematocrits and lower transfusions were seen.

Acute Normovolemic Hemodilution Reduces Allogeneic Red Blood Cell Transfusion in Cardiac Surgery: A Systematic Review and Meta-analysis of Randomized Trials.

To better understand the role of acute normovolemic hemodilution (ANH) in a surgical setting with high risk of bleeding, we analyzed all randomized controlled trials (RCTs) in the setting of cardiac surgery that compared ANH with standard intraoperative care. The aim was to assess the incidence of ANH-related number of allogeneic red blood cell units (RBCu) transfused. Secondary outcomes included the rate of allogeneic blood transfusion and estimated total blood loss. Twenty-nine RCTs for a total of 2439 patients (1252 patients in the ANH group and 1187 in the control group) were included in our meta-analysis using PubMed/MEDLINE, Cochrane Controlled Trials Register, and EMBASE. Patients in the ANH group received fewer allogeneic RBCu transfusions (mean difference = -0.79; 95% confidence interval [CI], -1.25 to -0.34; P = .001; I = 95.1%). Patients in the ANH group were overall transfused less with allogeneic blood when compared with controls (356/845 [42.1%] in the ANH group versus 491/876 [56.1%] in controls; risk ratio = 0.74; 95% CI, 0.62 to 0.87; P < .0001; I = 72.5%), and they experienced less postoperative blood loss (388 mL in ANH versus 450 mL in control; mean difference = -0.64; 95% CI, -0.97 to -0.31; P < .0001; I = 91.8%). ANH reduces the number of allogeneic RBCu transfused in the cardiac surgery setting together with a reduction in the rate of patients transfused with allogeneic blood and with a reduction of bleeding.

Pharmacokinetics and pharmacodynamics of cisatracurium in patients undergoing surgery with two hemodilution methods

ObjectiveTo investigate the pharmacokinetics and pharmacodynamics of cisatracurium in patients undergoing surgery under acute normovolemic hemodilution (ANH) and acute hypervolemic hemodilution (AHH). MethodsNinety patients with orthopedic surgery were divided into ANH, AHH and control groups, which received hemodilution by hydroxyethyl starch 130/0.4 transfusion, Voluven transfusion and regular transfusion and infusion during surgery, respectively. Each group was divided into 3 sub-groups, administrated with cisatracurium at dosage of 0.1, 0.2 and 0.3mg/kg respectively. The changes in plasma protein, pH and electrolytes from the hemodilution beginning to surgery finish were monitored. Before and after cisatracurium administration, the phamocodynamic indicators of muscle relaxant were observed, and the plasma drug concentration was measured. ResultsAfter hemodilution or regular transfusion, all three groups experienced a distinct drop in total plasma protein, albumin and pH. Compared with control group, the plasma concentrations of both K+ and Ca2+ in ANH and AHH groups significantly dropped (P<0.05), and those in each group after administration of cisatracurium also dropped, compared with before (P<0.05). After administration with cisatracurium, the onset time of muscle relaxation in AHH group was extended notably, compared with AHH and control groups (P<0.05), with no distinct difference of residual pharmacodynamics parameters (P>0.05). In the same hemodilution or regular infusion, with increase of drug dosage, the onset time of muscle relaxation was shortened, and the period of no response to train-of-four stimulation, muscle relaxation blockade duration and action time of muscle relaxation blockade in body were extended (P<0.05). ConclusionWhen using cisatracurium under AHH, the dosage should be increased appropriately, while it need not be adjusted under ANH.

Effectiveness of minimal acute normovolemic hemodilution to minimize allogenic blood transfusion and re-exploration in elective adult coronary artery bypass graft surgery using colloid as a replacement solution

Background and aim Various studies have questioned the efficacy of intraoperative acute normovolemic hemodilution (ANH) in reducing bleeding, the need for allogenic transfusion, and the incidence of re-exploration in cardiac surgery. The aim of the present study was to evaluate the effectiveness of the use of minimal ANH for blood transfusion requirements and re-opening in elective adult coronary artery bypass graft surgery using cardiopulmonary bypass. Patients and methods This prospective, randomized controlled study was conducted on 100 consecutive adult patients who underwent elective coronary artery bypass graft. Patients were randomly divided into two equal groups: the ANH group (n=50) and the control group (n=50). In the ANH group, 5–8 ml/kg of autologous blood was withdrawn after administering anesthesia and before systemic heparinization. Simultaneously, colloid solution (6% hydroxyethyl starch 130/0.4; Voluven) was infused in a ratio of 1:1, and then the blood was re-infused after bypass. Hemodilation was not carried out for the control group. Total amount of allogenic-packed red blood cell, fresh frozen plasma, platelet concentrate transfusion, and the number of patients undergoing re-opening because of excessive bleeding were calculated for the two groups. Results A significant decrease was observed in the number of red blood cell units and fresh frozen plasma transfusion per patient in the ANH group compared with the control group. Conversely, chest tube output, representing postoperative bleeding and platelet count, did not differ between the two groups. Conclusion In this study, the use of the minimal ANH technique reduced the consumption of allogenic red blood cells and fresh frozen plasma in adult cardiac surgery patients. However, this technique had no effect on postoperative bleeding, incidence of re-exploration, and platelet count.

Utility of Acute Normovolemic Hemodilution in Major Surgeries in Rural Area: A Prospective Comparative Study from North India.

Introduction:Easy availability of autologous blood is difficult in rural areas. Acute normovolemic hemodilution (ANH) has been found to be an effective alternative in major surgeries where we are expecting major blood loss.Patients and Methods:A prospective comparative study was designed to evaluate the utility of ANH patients (patients receiving autologous blood) during major operations done at MRA Medical College Ambedkar Nagar, Uttar Pradesh, India. during from September 2015 to September 2016. A total of 60 patients undergoing major surgeries were randomly assigned into two groups of thirty patients’ each. Group I received homologous blood intraoperative only when required. In Group II ANH was initiated to a target hematocrit of 30% after induction of anesthesia. Various parameters such as demographic, biochemical, and hemodynamic were compared.Results:The mean value of blood withdrawn in ANH group was 650.5 ± 228 ml and it was replaced with an equal volume of 6% hydroethyl starch. There was no statistically significant variation in mean hemocrits levels in both the groups at various stages of the study. Hematocrits decreased significantly in both the groups at various stages as compared to preoperative values. The heart rate and mean blood pressure were almost similar and without statistically significant differences in both groups. Surgical blood loss in Group I was 895.29 ± 568.30 ml as compared to 765 ± 506 ml in Group II. The difference was statistically insignificant (P ≥ 0.05). The mean volume of homologous blood transfused in Group I was 850.71 ± 318.29 ml, as compared to nil in Group II which was statistically significant (P < 0.05).Conclusion:It concludes that ANH up to a target hematocrit of 30% is safe and effective in reducing the need for homologous blood in various major surgeries in institutes in rural areas.

Acute Normovolemic Hemodilution in Total Knee Arthroplasty: A Prospective Study

In this prospective, randomized, controlled trial we sought to evaluate the effectiveness of acute normovolemic hemodilution (ANH) in terms of decreasing the need for allogeneic transfusion after conventional unilateral total knee arthroplasty (TKA). TKA is often performed with an occlusive tourniquet, and thus, it could be considered ideally suited for ANH, because the chief benefit of ANH is red blood cell loss reduction and the shedding of whole blood perioperatively at lower hematocrit levels. Between January 2012 and May 2012, 40 consecutive patients scheduled to undergo elective, primary, cemented, unilateral TKA for knee osteoarthritis were enrolled. Patients were randomized to either a study (ANH) group (n = 20; Group A) or a control group (n = 20; Group B). Units of allogeneic blood transfused was considered the primary outcome. In the ANH group, less allogeneic blood transfusion (6 units in Group A versus 15 units in Group B) was required after operation. Six patients, who required a transfusion in Group A received 1 unit of allogeneic blood. In contrast, 6 of 9 patients, who required transfusion in Group B, received at least 2 units of allogeneic blood (P &amp;lt; 0.05). There was no complication related to the methods of the protocol. ANH is likely to reduce postoperative allogeneic transfusion requirement in patients undergoing unilateral TKA. However, adjunctive strategies are required to further reduce allogeneic blood transfusion requirements.

Pre-operative blood donation versus acute normovolemic hemodilution in cardiac surgery.

Introduction:Acute normovolemic hemodilution (ANH) and preoperative autologous blood donation (PABD) have questionable efficacy, viral and bacterial infection risks, intermittent blood shortages as homeostasis problem, electrolyte and hemodynamic disturbances.Materials and Methods:In this cross sectional survey, we studied 70 patients undergoing open heart coronary artery bypass grafts [CABG] and different valvular replacement 1 ml surgery (35 in ANH, 35 in PABD) in Shaheed Modares - Hospital. We measured electrolytes and homeostatic factors to evaluate the influence of two transfusion methods on homeostatic function and hemodynamic balance.Results:We compared 70 patients (38 male [54.3%] and 32 female [45.7%]) with mean age 54.8 years undergoing open heart surgery (CABG and valvular). In ANH group, significant decrease was detected in Na (28.5%) K (2.5%), prothrombin time (PT) (88.57%), partial thromboplastin time (PTT) (94.28%), creatine phosphokinase (CPK) (11.4%), lactic dehydrogenase (LDH) (11.43%), albumin (Alb) (17.14%), globulin (91.43%) and total protein (80%). Mean initial and post-operative hemoglobin was 14.12 ± 1.06 versus 11.97 ± 0.98, hematocrit 42.22 ± 3.45 versus 35.40 ± 2.88, systolic blood pressure 124.1 ± 14.4 versus 110.88 ± 15.6 (reduction 22.86%) diastolic blood pressure 76.02 ± 10 versus 69.26 ± 11 (reduction 3%) and pulse rate was 75.45 ± 10 versus 84.45 ± 12 (12%) in this case difference between two groups was strongly significant (P = 0.001). In PABD group, significant decrease was detected in Na (20%), K (2.5%), PT (91.43%) PTT (80%), CPK (8.57%), LDH (5.72%), Alb (57.15%), globulin (71.43%) and total-protein (62.85%), the value of hemodynamic changes were in normal range.Conclusion:Though autologous blood transfusion (ANH and PABD) was preferable to allogeneic transfusion in cardiac surgical patients; but PABD offers more advantages in homeostasis, hemodynamic stability and electrolyte balance.

Acute Normovolemic Hemodilution Effects on Perioperative Coagulation in Elderly Patients Undergoing Hepatic Carcinectomy

Acute normovolemic hemodilution (ANH) has been widely used to prevent the massive blood loss during hepatic carcinoma. The influences of ANH on coagulation function are still controversy, especially in elderly patients. The study observed ANH effects on coagulation function and fibrinolysis in elderly patients undergoing the disease. Thirty elderly patients (aged 60-70 yr) with liver cancer (ASA I or II) taken hepatic carcinectomy from February 2007 to February 2008 were randomly divided into ANH group (n=15) and control group (n=15). After tracheal intubation, patients in ANH group and control group were infused with 6% hydroxyethyl starch (130/0.4) and Ringer's solution, respectively. Blood samples were drawn from patients in both groups at five different time points: before anesthesia induction (T1), 30 min after ANH (T2), 1 h after start of operation (T3), immediately after operation (T4), and 24 h after operation (T5). Then coagulation function, soluble fibrin monomer complex (SFMC), prothrombin fragment (F1+2), and platelet membrane glycoprotein (CD62P and activated GP IIb/GP IIIa) were measured. The perioperative blood loss and allogeneic blood transfusion were recorded during the surgery. The perioperative blood loss was not significantly different between two groups (p>0.05), but the volume of allogeneic blood transfusion in ANH group was significantly less than in control group (350.0±70.7) mL vs. (457.0±181.3) mL (p<0.01). Compared with the data of T1, the prothrombin time (PT) and activated partial thromboplastin time (APTT) measured after T3 were significantly longer (p<0.05) in both groups, but within normal range. There were no significant changes of thrombin time (TT) and D-dimer between two groups at different time points (p>0.05). SFMC and F1+2 increased in both groups, but were not statistically significant. PAC-1-positive cells and CD62P expressions in patients of ANH group were significantly lower than those at T1 (p<0.05) and T2-T5 (p>0.05). ANH has no obvious impact on fibrinolysis and coagulation function in elderly patients undergoing resection of liver cancer. The study suggested that ANH is safe to use in elderly patients and it could reduce allogeneic blood transfusion.

Responsiveness of stroke volume variation and central venous pressure during acute normovolemic and hypervolemic hemodilution.

Stroke volume variation (SVV) is a robust indicator of fluid responsiveness during volume change. We compared the sensibility of SVV by Vigileo/Flotrac to central venous pressure (CVP) when volume changes in patients undergoing intraoperative acute normovolemic hemodilution (ANH) and acute hypervolemic hemodilution (AHH). Forty patients were randomly divided into an ANH group (n = 20) and an AHH group (n = 20). All patients received general anesthesia and were mechanically ventilated. Data were collected from 7 different time-points in the ANH group: baseline, after withdrawal of 5%, 10%, and 15% of the estimated blood volume (EBV) and after replacement with an equal volume of 6% hydroxyethyl starch 130/0.4 (HES) in 5% EBV increments to baseline. There were four time points in the AHH group: baseline, after 5%, 10%, and 15% expansion of the EBV with 6% HES. At each time-point, CVP, SVV and other hemodynamic parameters measurements were obtained. After removal of 10% and 15% EBV, SVV significantly increased from 10.9 ± 3.0 to 14.1 ± 3.4 and 10.9 ± 3.0 to 16.0 ± 3.3 (P < 0.01), and returned to a final value of 10.6 ± 3.4 after volume replacement. The CVP value was unchanged after removal and replacement of 15% of the EBV. There were no significant changes in SVV after 5%, 10% whereas there was a significant reduction after 15% (8.2 ± 1.7) expansion of the EBV compared with baseline (9.9 ± 1.8) (P = 0.033). However, there was a significant increase in CVP after 10% (10.3 ± 2.4), 15% (11.3 ± 2.2) expansion of the EBV compared with baseline (8.2 ± 2.7) (P < 0.01). SVV is a more sensitive parameter for volume than CVP during hypovolemia, on the contrary CVP is more sensitive than SVV during hypervolemia.

Evaluation of acute normovolemic hemodilution and autotransfusion in neurosurgical patients undergoing excision of intracranial meningioma

Several blood conservation strategies have been tried with the purpose of reducing homologons blood transfusion. PATIENTS #ENTITYSTARTX00026; In a prospective randomized study, the potential benefits of acute normovolemic hemodilution (ANH) with autologous transfusion were investigated as a blood conservation technique in surgical excision of intracranial meningioma. Over a period of 2 years, 40 patients undergoing excision of intracranial meningioma were randomly assigned to two groups of 20 patients each. Group I (Control Group) received conventional homologous blood intraoperatively and were not subjected to ANH. In Group II (ANH Group), Acute Normovolemic Hemodilution was initiated to a target hematocrit of 30% after induction of anesthesia. Parameters studied included changes in hemoglobin, hematocrit and hemodynamic parameters. The mean value of blood withdrawn in ANH group was 802.5 ± 208 ml. This was replaced simultaneously with an equal volume of 6% Hydroxyethyl starch to maintain normovolemia. There was no statistically significant variation in mean hemoglobin levels between the two groups at various stages of study. Hematocrit decreased significantly in both the groups at various stages as compared to preoperative values , the decrease being more but insignificant in group II. Changes in heart rate and mean blood pressure were similar and without statistically significant differences in either group at various stages of study. The amount of surgical blood loss in group I was 835.29 ± 684.37 ml, as compared to 865 + 409.78 ml in group II. The difference was statistically insignificant (p>0.05). The mean volume of homologous blood transfused in group I was 864.71 ± 349.89 ml, as compared to 165 ± 299.6 ml in group II which was statistically significant (p<0.05). In group II (ANH Group) only 5 patients (25%) required homologous blood whereas in group I I all patients (100%) needed homologous blood. We conclude that acute normovolemic hemodilution up to a target hematocrit of 30% is safe and effective in reducing the need for homologous blood in neurosurgical patients undergoing excision of intracranial meningioma.

Relationship Between Intraoperative Fluid Administration and Perioperative Outcome After Pancreaticoduodenectomy

Pancreaticoduodenectomy (PD) can be associated with significant blood loss and transfusion requirements, with potential adverse short- and long-term consequences. The aim of this study was to determine whether acute normovolemic hemodilution (ANH), an established blood conservation technique, reduces perioperative allogeneic transfusions in patients undergoing PD. One hundred thirty patients undergoing PD were randomized to ANH or standard management (STDM). In the ANH group, intraoperative blood collection was performed to a target hemoglobin of 8.0 g/dL; crystalloid and colloid were used for volume replacement. Strict transfusion triggers were applied during and after operation. Perioperative complications were prospectively assessed and graded for severity. From July 2005 to May 2009, 209 patients were registered, 79 excluded, 65 were randomized to ANH, and 65 to STD. The groups were well matched for demographic, operative, and histopathologic variables. Patients undergoing ANH received over 2 L more fluid intraoperatively (6250 mL, range 2000-11850) compared with patients undergoing STD (3900 mL, range 2000-9000) (P < 0.001). Transfusion rates were similar (ANH = 16.9%, 30 units vs STD = 18.5%, 33 units; P = 0.82), as was overall perioperative morbidity (ANH = 49.2% vs STD = 47%, P = 0.86). There was, however, a trend toward more grade-3 complications in patients undergoing ANH (32% vs 23.1% STD, P = 0.17), and complications related to the pancreatic anastomosis (leak/fistula/abscess) were significantly higher in the ANH group (21.5% vs 7.7%, P = 0.045). The intraoperative fluid volume was higher for all patients with pancreatic anastomotic complications (n = 19), regardless of randomization arm (ANH 6000 mL, range 2800-11350 mL vs STD 5000 mL, range 2000-11850 mL, P < 0.042). In this randomized trial of patients undergoing PD, ANH did not reduce allogeneic transfusions and resulted in more pancreatic anastomotic complications, likely related to greater intraoperative fluid administration. The benefits of ANH do not necessarily extend to all procedures, and restrictive intravenous fluid management during PD may help improve postoperative outcome.

Effects of Acute Normovolemic Hemodilution on Perioperative Coagulation and Fibrinolysis in Elderly Patients Undergoing Hepatic Carcinectomy

To observe the effects of acute normovolemic hemodilution (ANH) on coagulation function and fibrinolysis in elderly patients undergoing hepatic carcinectomy. Thirty elderly patients (aged 60-70 years) with liver cancer (American Society of Anesthesiologists physical status I-II) scheduled for hepatic carcinectomy from February 2007 to February 2008 were randomly divided into ANH group (n = 15) and control group (n = 15). After tracheal intubation, patients in ANH group and control group were infused with 6% hydroxyethyl starch (HES) (130/0.4), and basic liquid containing 6% HES and routine Ringer's solution, respectively. In all the studied patients, blood samples were drawn at five different time points: before anesthesia induction (T1), 30 minutes after ANH (T2), 1 hour after start of operation (T3), immediately after operation (T4), and 24 hours after operation (T5). Then coagulation function, soluble fibrin monomer complex (SFMC), prothrombin fragment (F1+2), and platelet membrane glycoprotein (activated GPIIb/GPIIIa and P-selectin) were measured. The perioperative blood loss was not significantly different between the two groups (P > 0.05). The volume of allogeneic blood transfusion in ANH group was significantly smaller than that in control group (350.5 +/- 70.7 mL vs. 457.8 +/- 181.3 mL, P < 0.01). Compared with the data of T1, prothrombin time (PT) and activated partial thromboplastin time in both groups prolonged significantly after T3 (P < 0.05), but still within normal range. There were no significant changes in thrombin time and D-dimer between the two groups and between different time points in each group (all P > 0.05). SFMC and F1 + 2 increased in both groups, but without statistical significance. P-selectin expression on the platelet surface of ANH group was significantly lowered at T2 and T3 compared with the level at T1 (P < 0.05). Compared with control group, P-selectin was significantly lower in ANH group at T2-T5 (all P < 0.05). In elderly patients undergoing resection of liver cancer, ANH may not hamper fibrinolysis and coagulation function. It could therefore be safe to largely reduce allogeneic blood transfusion.

Effects of different degrees of acute normovolemic hemodtiution on serum S-100B protein concentration and cerebral oxygen metabolism in rabbits

Objective To investigate the effects of different degrees of acute normovolemic hemodilution (ANH) with 6% HES 20010.5 on serum S-100B protein concentration and cerebral oxygen metabolism at 37℃ in rabbits.Methods Thirty-two adult rabbits weighing 2.0-2.5 kg were randomly assigned into 4 groups (n = 8each) : Ⅰ control group underwent no ANH and Ⅱ , Ⅲ , Ⅳ ANH group underwent ANH with hematocrit (Hct)reduced to 24%, 18% and 12% respectively. The animals were anesthetized with iv 20% urethane 5 ml/kg,tracheostomized and mechanically ventilated (VT = 15 ml/kg, RR = 30 bpm). The body temperature was maintained at 37℃. Left carotid artery and jugular vein were cannulated for BP monitoring, blood gas analysis and blood sampling. Right jugular vein was cannulated for CVP monitoring. Left femoral artery and vein were cannulated for hemodilution. Blood withdrawn from femoral artery was simultaneously replaced by iv infusion of equal volume of HES (200/0.5) until the target Hct was achieved. Hemodynamics parameters, were recorded and blood gases were analyzed and serum S-100B protein concentration and cerebral O2 metabolic rate (CERO2) were determined before (baseline) and at 2, 4 and 8 h after ANH. Brain water content was measured by wet/dry brain weight ratio. Results There were no significant differences in serum S-100B protein concentration, CERO2 and pH value between group Ⅰ and group Ⅱ (Hct 24%). Serum S-100B protein concentration and CERO2 were significantly increased at 8 h after ANH as compared with the baseline before ANH in group Ⅰ (Her 18%). Serun S-100B protein concentration and CERO2 were significantly increased at 2, 4 and 8 h after ANH as compared with the baseline before ANH in group Ⅳ (Hct 12%). There was no significant difference in brain water content among the 4 groups. Conclusion ANH does not affect cerebral O2 metabolic when Hct is reduced to 24%. CERO2 can not be sustained and ischemic cerebral injury may occur when Hct is reduced to≤18%. Key words: Hemodilution ; S100 proteins; Brain ; Oxygen consumption

A Prospective Randomized Trial of Acute Normovolemic Hemodilution Compared to Standard Intraoperative Management in Patients Undergoing Major Hepatic Resection

Hepatic resection is the most effective treatment for many malignant and benign conditions affecting the liver and biliary tree. Despite improvements, major partial hepatectomy can be associated with considerable blood loss and transfusion requirements. Transfusion of allogeneic blood products, although potentially life-saving, is associated with many potential complications. The primary aim of this study was to determine if acute normovolemic hemodilution (ANH), an established blood conservation technique, reduces the requirement for allogeneic red cell transfusions in patients undergoing major hepatic resection. One hundred thirty patients undergoing major hepatic resection (> or =3 segments) were prospectively randomized to undergo either ANH or standard anesthetic management (STD). In the ANH group, intraoperative blood collection was performed to a target hemoglobin of 8.0 g/dL. Low central venous pressure anesthetic technique was used intraoperatively for both groups. A standardized transfusion protocol was applied to all patients intraoperatively and throughout the hospital stay. From April 2004 to March 2007, 63 patients were randomized to ANH and 67 to STD. Demographics, diagnoses, liver function, extent of resection, intraoperative blood loss, operative time, incidence and grade of complications, and length of hospital stay were similar between the 2 groups. ANH reduced the overall allogeneic red cell transfusion rate by 50% compared with STD [12.7% (n = 8) vs. 25.4% (n = 17), respectively; P = 0.067. ANH patients were less often transfused intraoperatively (n = 1, 1.6%) compared with the STD group (n = 7, 10.4%) (P = 0.036), had higher postoperative hemoglobin levels (P = 0.01), and tended to require fewer red cell units overall (28 vs. 47 units). In patients with intraoperative blood loss > or =800 mL, ANH reduced not only the allogeneic red cell transfusion rate (18.2% vs. 42.4%, P = 0.045) but also the proportion of patients requiring fresh frozen plasma (21.1% vs. 48.3%, P = 0.025). For patients undergoing major liver resection, ANH is safe, effectively reduces the need for allogeneic transfusions, and should be considered for routine use. Given the modest transfusion rate in the STD arm, future efforts should attempt to target ANH use to patients most likely to benefit.

Acute normovolaemic haemodilution with crystalloids in coronary artery bypass graft surgery: a preliminary survey of haemostatic markers

Introduction — Acute normovolaemic haemodilution (ANH) is a safe and cost-effective blood conservation strategy in procedures with great blood loss. It eliminates the risk of administrative errors and also contaminations that may occur whenever banked blood is used. Classically, haemodilution is regarded as causing coagulopathy.This study was designed to determine the effect of crystalloids on measured coagulation values and perioperative blood loss following ANH in patients undergoing elective coronary revascularization.Methods — Following a prospective case-control study one hundred candidates for CABG (50 cases in the ANH group and 50 in the control group) were included. Blood samples for coagulation testing haematocrit and platelet levels were collected before ANH, after cardiopulmonary bypass (CPB), and upon arrival at the intensive care unit (ICU). Differences were considered statistically significant with Pvalues < 0.05.Result — There was no statistically significant difference between chest tube drainage in the two groups. The number of patients using PRBC (packed red blood cell) or FFP (fresh frozen plasma) was significantly higher in the control group in comparison to the ANH group (P < 0.05). The PT increased significantly after arrival in the ICU in both groups (P < 0.001) but there was no betweengroup difference (P = 0.22). aPTT not only did not change significantly in the ICU relative to the baseline pre ANH values in both groups (P > 0.05) but also did not show any between-group difference (P = 0.69). There was no statistically significant difference in the aCT of the control and the ANH group after arrival to the ICU (P= 0.09). Hct and Plt decreased significantly in both groups after CPB and arrival at ICU.Conclusion — ANH reduced the need for PRBC and FFP by 58% and 74%, respectively. Regarding the increase in PT and decrease in Plt count, we concluded that performing ANH with saline solution (SS) in patients undergoing CABG surgery may cause a non-clinically significant change in coagulation state.

Influence of acute normovolaemic haemodilution on the dose–response relationship and time course of action of cisatracurium besylate

Acute normovolaemic haemodilution (ANH) is an efficacious blood conservation strategy aiming at avoiding allogeneic blood transfusion. ANH was shown to increase the potency of vecuronium, atracurium, and rocuronium. The aim of our study was to investigate whether cisatracurium potency is altered with ANH. Using the Relaxometer mechanomyograph, we compared cisatracurium dose-response relationship and time course of action in 60 patients randomly allocated to the ANH or control groups. Patients in each group were randomly allocated to receive one of three cisatracurium doses (30, 40, 50 microg kg(-1)) followed by a second supplemental dose to reach a total of 100 microg kg(-1). ANH did not result in a significant shift in cisatracurium log dose-probit dose-response curve. There was no significant difference in mean (95% confidence intervals) ED(50), ED(90), and ED(95) (effective doses required for 50, 90, and 95% first twitch depression) between the ANH group [29.5 (27-32), 50.4 (47.4-53.4), 58.7 (55.3-62) microg kg(-1)] and the control group [28.2 (25.3-31), 47.6 (44.9-50.3), 55.3 (52.5-58.1) microg kg(-1)], whereas there was no difference in mean (SD) Dur(25) and Dur(0.8) (time until 25% first twitch and 0.8 train-of-four ratio recoveries) between the ANH group [40.8 (5.9), 64.7 (8.4) min] and the control group [42.2 (7.6), 66.5 (10.7) min]. Our results demonstrated that unlike other previously reported neuromuscular blocking drugs, ANH did not alter cisatracurium potency. Thus, cisatracurium would be the neuromuscular blocking drug of choice in patients who undergo surgery with ANH, as no dose adjustments are required.

Influence of acute normovolaemic haemodilution on the dose–response relationship, time-course of action and pharmacokinetics of rocuronium bromide

Acute normovolaemic haemodilution (ANH) is an effective strategy for avoiding or reducing allogeneic blood transfusion. We aimed to study its effect on the pharmacological profile of rocuronium. In two study centres, 28 patients undergoing major surgery with ANH were matched with 28 control patients. In the dose-response groups, using the mechanomyograph, neuromuscular block of six consecutive incremental doses of rocuronium 50 microg kg(-1), followed by 300 microg kg(-1), was evaluated. In the pharmacokinetics groups, serial arterial blood samples were withdrawn for rocuronium assay after a single dose of rocuronium 600 microg kg(-1). ANH resulted in a shift to the left of rocuronium dose-response curve. Rocuronium effective dose(95) (ED(95)) was 26% lower (P<0.05) in the ANH group [283.4 (92.0) microg kg(-1)] compared with the control group [383.5 (127.3) microg kg(-1)]. Times from administration of last incremental dose until 25% of first response of train-of-four (TOF) recovery (Dur(25)) and 0.8 TOF ratio recovery (Dur(0.8)) were 28% longer in the ANH group [39.9 (8.4), 66.7 (14.2) min] compared with the control group [31.1 (6.6), 52.1 (15.8) min] (P<0.01, P<0.05), respectively. Volume of distribution was higher (P<0.01), central clearance was lower (P<0.05) and terminal elimination half-life was longer (P<0.0001) in the ANH group [234.97 (47.11) ml kg(-1), 4.70 (0.94) ml kg(-1) min(-1), 77.29 (12.25) min] compared with the control group [181.22 (35.73) ml kg(-1), 5.71 (1.29) ml kg(-1) min(-1), 56.86 (10.05) min, respectively]. ANH resulted in prolongation of rocuronium time-course of action, thus careful monitoring of neuromuscular block is recommended in patients who undergo ANH.