Effects Of Hemodilution Research Articles

In vitro and in vivo effects of hemodilution on kaolin-based activated clotting time predicted heparin requirement using a heparin dose-response technique.

The heparin dose-response (HDR) technique is based on activated clotting time (ACT) response to a fixed-dose heparin bolus, which varies substantially among patients. It is unclear, however, whether hemodilution-associated reductions in coagulation and anticoagulation factors affect the HDR slope. For in vitro hemodilution, aliquots of whole blood from healthy volunteers were diluted 9:1 and 8:2 v/v with normal saline. For in vivo hemodilution, a prospective observational study was performed on 46 patients who underwent elective cardiovascular surgery with or without cardiopulmonary bypass. HDR slope, antithrombin (AT) activity, complete blood count, and other coagulation parameters were compared after induction of anesthesia and after hemodilution with 500ml of intravenous fluid. In vitro 10 and 20% hemodilution significantly increased the HDR slope relative to baseline, reducing the heparin requirement. Hemodilution of heparinized samples significantly prolonged ACT, whereas there was no significant change in non-heparinized blood. The percent changes in fibrinogen and AT activity were significantly greater at 20% than those of the other coagulation variables. In vivo, hemodilution significantly increased the HDR slope and reduced heparin requirement. The percent change in fibrinogen due to hemodilution was significantly greater than the change in AT activity. Target ACTs of 300 and 450s were not achieved in 83.3 and 53.8% of patients, respectively. In vitro and in vivo hemodilution significantly increased the HDR slope and reduced the requirement for heparin. In vitro, the HDR slope did not change in parallel but became steeper, depending on the degree of hemodilution.

The Effect of Normovolemic and Hypervolemic Hemodilution on a Perforator Flap with Twisted Pedicle Model: Experimental Study in Rats.

Several studies showed the detrimental effect of pedicle torsion on flap survival; however, the impact of hemodilution in this peculiar condition has never been investigated. This study evaluated the effect of acute normovolemic and hypervolemic hemodilution on flap survival in a perforator flap with twisted pedicle model. Sixty-three female Wistar rats were divided into three groups of 21 rats each: group 1, superficial inferior epigastric artery flap, which was elevated bilaterally and transposed back to the abdominal wall with different angles of rotation (i.e., 90, 180, 270, and 360 degrees); group 2, surgery with previous acute normovolemic hemodilution; and group 3, surgery with previous acute hypovolemic hemodilution. Normovolemic hemodilution was obtained, simultaneously removing 2 cc of blood and replacing it with an equal volume of isotonic sodium chloride 0.9% (two-thirds) plus hydroxyethyl starch 6% (one-third). Hypervolemic hemodilution was obtained by hemodilution and a 20 percent blood volume expansion. Microangiography of the flap and histopathologic analyses were performed. Mean hematocrit values after hemodilution were 27.80 ± 0.04 percent for the acute normovolemic hemodilution group and 27.01 ± 0.03 percent for the acute hypovolemic hemodilution group. Twisting the pedicle at 90, 180, and 270 degrees had no effect on flap survival in all groups. However, 360-degree pedicle torsion showed flap edema, congestion, and necrosis. The authors' hemodilution protocol is an effective and reliable method that could be used to further investigate the impact of the hemodynamic changes that occur during hemodilution on flap microcirculation. The results obtained sustain the existence of a strong correlation between necrosis rate and hemodilution.

Impaired microcirculatory perfusion in a rat model of cardiopulmonary bypass: the role of hemodilution.

Although hemodilution is attributed as the main cause of microcirculatory impairment during cardiopulmonary bypass (CPB), this relationship has never been investigated. We investigated the distinct effects of hemodilution with or without CPB on microvascular perfusion and subsequent renal tissue injury in a rat model. Male Wistar rats (375-425 g) were anesthetized, prepared for cremaster muscle intravital microscopy, and subjected to CPB (n = 9), hemodilution alone (n = 9), or a sham procedure (n = 6). Microcirculatory recordings were performed at multiple time points and analyzed for perfusion characteristics. Kidney and lung tissue were investigated for mRNA expression for genes regulating inflammation and endothelial adhesion molecule expression. Renal injury was assessed with immunohistochemistry. Hematocrit levels dropped to 0.24 ± 0.03 l/l and 0.22 ± 0.02 l/l after onset of hemodilution with or without CPB. Microcirculatory perfusion remained unaltered in sham rats. Hemodilution alone induced a 13% decrease in perfused capillaries, after which recovery was observed. Onset of CPB reduced the perfused capillaries by 40% (9.2 ± 0.9 to 5.5 ± 1.5 perfused capillaries per microscope field; P < 0.001), and this reduction persisted throughout the experiment. Endothelial and inflammatory activation and renal histological injury were increased after CPB compared with hemodilution or sham procedure. Hemodilution leads to minor and transient disturbances in microcirculatory perfusion, which cannot fully explain impaired microcirculation following cardiopulmonary bypass. CPB led to increased renal injury and endothelial adhesion molecule expression in the kidney and lung compared with hemodilution. Our findings suggest that microcirculatory impairment during CPB may play a role in the development of kidney injury.

Comparison of early period results of blood use in open heart surgery.

Background:Various adverse effects of homologous blood transfusion detected particularly in open heart surgery, in which it is frequently used, lead researchers to study on autologous blood use and to evaluate the patient's blood better. Due to the complications of homologous blood transfusion, development of techniques that utilize less transfusion has become inevitable. We aimed to evaluate the effects of acute normovolemic hemodilution (ANH) in patients undergoing open heart surgery.Materials and Methods:In this study, 120 patients who underwent open heart surgery were included. Patients were grouped into three: Autologous transfusion group (Group 1), homologous transfusion group (Group 2), and those received autologous blood and homologous blood products (Group 3). Patient data regarding preoperative characteristics, biochemical parameters, drainage, extubation time, duration of stay at intensive care, atrial fibrillation (AF) development, and hospital stay were recorded.Results:A statistically significant difference (P < 0.005) was found in favor of autologous group (Group 1) with respect to gender, body surface area, European System for Cardiac Operative Risk Evaluation, smoking, hematocrit levels, platelet counts, urea, C-reactive protein levels, protamine use, postoperative drainage, frequency of AF development, intubation period, stay at intensive care and hospital stay, and amount of used blood products.Conclusion:The use of autologous blood rather than homologous transfusion is not only attenuates side effects and complications of transfusion but also positively affects postoperative recovery process. Therefore, ANH can be considered as an easy, effective, and cheap technique during open heart surgery.

Effect of preoperative hypervolemic hemodilution with hydroxyethyl starch (130/0.4) on hemodynamics, blood loss and renal function after laparoscopic gastric bypass surgery

BackgroundIn a trial to overcome the adverse effects of pneumoperitoneum during laparoscopic gastric bypass surgery (GBP) on renal function this study investigated the effects of third generation HES 130/0.4 (6%) on renal function and blood loss during laparoscopic GBP.Patients and methodsThis study was carried out on 83 adult patients of both sexes scheduled for (GBP) surgery. Patients were randomly classified into Group I (42): received HES 130/0.4 10 ml/kg to a maximum volume 1000 ml, and Group II (41): received ringer acetate solution 10 ml/kg to a maximum volume 1000 ml within 30 min pre-operatively.Mean arterial blood pressure (MABP) and heart rate (HR) were measured before starting of fluid infusion, and every 15 min till the end of surgery. Blood loss was assessed intraoperatively and postoperatively.Intraoperative urine output was observed. Renal functions (blood urea, serum creatinine, and creatine clearance) were evaluated preoperatively and after 24 h postoperatively.ResultsIntraoperative and postoperative blood loss was comparable in both groups. Changes in mean arterial blood pressure (MABP), and heart rate (HR) were comparable in both groups except significant increase in MABP in group I from 30 min till 150 min intraoperatively (p values were 0.04, 0.03, 0.02, 0.04, 0.01, respectively). Creatinine clearance increased significantly at postoperative assessment time in group I, (p = 0.04). There was no significant difference between both groups regarding serum creatinine and blood urea. Intraoperative urine output significantly increased in group I, (p = 0.02).ConclusionInfusion of HES 130/0.4 has role in prevention of oliguria and provides renal protection without effect on hemostasis and intraoperative or postoperative blood loss.

Effect of acute hypervolemic hemodilution of 6% hydroxyethyl starch 130/0.4 on the EC50 of propofol at two clinical endpoints in patients.

Preoperative acute hypervolemic hemodilution (AHHD) is a technique used in anesthesia to reduce the number of blood cells lost during intraoperative bleeding. The aim of the present study was to evaluate the effect of the hypervolemic hemodilution of 6% hydroxyethyl starch 130/0.4 on the EC50 of propofol at two clinical endpoints. A total of 20 patients undergoing AHHD following epidural anesthesia were studied, and 20 patients who did not receive hemodilution were used as a control group. All patients were American Society of Anesthesiologists grade I, aged 20–40 years and undergoing hip arthroplasty surgery. In the AHHD group, 10 ml/kg lactated Ringer's solution was infused over 20 min at the same time as the epidural test dose. The infusion was followed by the infusion of 6% hydroxyethyl starch 130/0.4 over 30 min. Patients in the control group received 10 ml/kg Ringer's solution over 50 min. Propofol was then delivered by a Diprifusor target-controlled infusion. The predicted blood and effect-site propofol concentrations were recorded at loss of consciousness (LOC) and return of consciousness (ROC). Probit analysis was used to estimate the values for predicted blood and effect-site concentrations at the two clinical endpoints. The results showed that the potency of propofol was decreased during AHHD. Compared with the controls, the predicted blood and effect-site concentrations of propofol at LOC were higher in patients of the hemodilution group, resulting in higher EC50 values (P=0.001 and 0.025, respectively). At ROC, the effect-site EC50 was 2.9 µg/ml [95% confidence interval (CI), 2.8–3.0] in hemodilution patients and 2.5 µg/ml (95% CI, 2.2–2.6) in control patients (P=0.001). With AHHD, the LOC time was significantly longer and the propofol dose was higher, while ROC times were comparable. In conclusion, AHHD increases the requirement for propofol at LOC and prolongs LOC time. Patients with AHHD recovered consciousness at higher effect-site concentrations of propofol. Thus, the induction dose of propofol should be increased during AHHD.

The effects of haemodilution with hydroxyethyl starch 130/0.4 solution on coagulation as assessed by thromboelastography and platelet receptor function studies in vitro.

This study evaluated the effects of haemodilution with either 6% hydroxyethyl starch (HES) 130/0.4 (Voluven(®)) or 0.9% normal saline (NS) on blood coagulation in vitro. Haemodilution with 6% HES 130/0.4 impaired coagulation, as indicated by the changes in thromboelastographic parameters k-time, α-angle and maximum amplitude. Light transmission aggregometry and multiple electrode aggregometry demonstrated that impaired platelet receptor function occurred only at high levels of haemodilution (40%) with both fluids, but there was no significant difference between the two fluids (P=0.05). The thromboelastographic functional fibrinogen assay showed that the fibrinogen component of clot strength was significantly impaired with haemodilution with HES 130/0.4 compared with haemodilution with NS (whole blood [14.4 ± 4.6 mm] versus 40% HES dilution [3.7 ± 1.9], [P=0.001]; versus 40% NS dilution [10.4 ± 4.6], [P=0.129]). These findings suggest that there is little difference between HES or NS in relation to coagulation or platelet function during minor or moderate haemodilution, but at high levels of haemodilution with HES, fibrinogen activity is more impaired compared with NS.

Ideal Hematocrit to Minimize Renal Injury on Cardiopulmonary Bypass.

Renal dysfunction after cardiopulmonary bypass (CBP) ranges from subclinical injury to established renal failure requiring dialysis. The pathophysiology is multifactorial, and recently, hemodilution during CBP has been thought to be an important determinant of postoperative renal injury. In this study, we attempted to assess the independent effect of hemodilution on renal function. We also aimed to identify the optimal hematocrit where hemodilution-induced renal injury is minimal. A prospective observational study was conducted on 200 patients between February 2012 and July 2013. One hundred fifty patients were included in the study group, who were further subdivided on the basis of lowest hemodilution as mild hemodilution (>25%), moderate hemodilution (21%-25%), and severe hemodilution (<21%) categories. The primary outcome of the study was renal outcome measure, which was assessed by comparing the creatinine clearance across the groups. The creatinine clearance decreased over a period in all three groups. When compared with mild or moderate hemodilution, the reduction in creatinine clearance was significantly higher in the group with severe hemodilution (P ≤ 0.0001). However, there was no significant difference in creatinine clearance reduction between the mild and moderate hemodilution groups (P = 0.813; 95% confidence interval, -8.41 to 10.68). Based on our observations, we would like to propose that a hematocrit of 21% should be considered the critical threshold. Hematocrit below this value of 21% during CBP is associated with the most significant deterioration in renal function.

Peripheral circulation evaluation with near-infrared spectroscopy in skeletal muscle during cardiopulmonary bypass.

We designed a non-invasive, observational, real-time study, using near-infrared spectroscopy (NIRS) to assess the in vivo effects of cardiopulmonary bypass (CPB) on patients' skeletal muscle as well as the effects of hemodilution and hypothermia on tissue oxygen delivery during CPB. The study included 20 consecutive adult patients undergoing open-heart surgery with CPB. Evaluation parameters for peripheral circulation were measured using the NIRO-200NX and recorded every 30 seconds. To assess how hemodilution influences peripheral circulation parameters, we compared data between a group of patients with hematocrit (Hct) values >22% (high Hct group) and those with Hct values ⩽22% (low Hct group). Changes in the concentration of oxygenated hemoglobin (ΔO2Hb, μmol/L), which flows into the skeletal muscle, was an important factor for deciding the tissue oxygenation index (TOI%), showing the tissue oxygen saturation. The low Hct group showed a significant increase in the normalized tissue hemoglobin index (nTHI), showing the percentage change in the amount of initial hemoglobin and TOI compared to the high Hct group. Changes in the concentration of oxygenated hemoglobin (ΔO2Hb, μmol/L) and deoxygenated hemoglobin (ΔHHb, μmol/L) were significantly less in the low Hct group than in the high Hct group, thus, showing good peripheral circulation despite the low hematocrit levels. Our study indicated the presence of a compensatory mechanism in which increased blood flow of the microcirculation is in compensation for the lack of oxyhemoglobin delivery caused by hemodilution.

Effects of Hemodilution and Transfusion on Acute Renal Injury and Neutrophil Gelatinase-Associated Lipocalin.

Dear Editor, We read the article titled “The Value of Urinary Neutrophil Gelatinase-Associated Lipocalin for Early Detection of Acute Renal Injury in Patients Undergoing Cardiopulmonary Bypass “ with a great interest (1). The fact that early diagnosis and treatment of acute renal injury can prevent delay-induced increase in morbidity and mortality is known and also specified by the authors. As stated by the authors, impaired renal perfusion and development of renal injury are resulted from many reasons. It has been reported in some studies that decreased haematocrit value associated with hemodilution developing during cardiopulmonary bypass leads to renal injury (2–4). The authors mentioned that extended time of cardiopulmonary bypass, cross-clamp, and intubation increased the risk of the possibility for the development of acute renal injury. However, they did not tell about preoperative haemoglobin, haematocrit, cardiac output values, and hemodynamic factors, which are known to be the most important parameters affecting renal perfusion of patients, and also about their changes in periopeative period and their effect on the development of acute renal injury. Moreover, studies have demonstrated that blood transfusions performed to patients in perioperative period also cause acute renal injury and an increase in the values of neutrophil gelatinase-associated lipocalin (NGAL) in early period (3, 5). In this study, whether patients received transfusion or not and if received, its effect on the development of acute renal injury were not explained in this study. We think that if the study aims to detect the risk factors in patients with renal injury development and altered NGAL, the evaluation of the relationship between the development of renal injury and the changes in haemoglobin, haematocrit, cardiac output, and haemodynamic parameters during perioperative period influencing renal perfusion will contribute to the determination of risk factors. We congratulate the authors on this current study that draws attention on an important issue. We suggest that further studies should be performed on acute renal injury and its early markers. In the light of data obtained in these studies, the frequency of acute renal injury can be reduced by detecting the factors leading to acute renal injury and early diagnostic markers.

Effect of acute hypervolemic hemodilution on myocardial damage in severely burned rabbits

Objective To evaluate the effect of acute hypervolemic hemodilution(AHH)on myocardial damage in severely burned rabbits. Methods Eighteen healthy adult rabbits, weighing 2.0-2.5 kg, were randomly divided into 3 groups(n=6 each)using a random number table: control group(group C), burn group(B group)and AHH group.Rabbits were subjected to 3rd degree burn covering 40% of the total body surface area.After the model was established, 6% hydroxyethyl starch 130/0.4 was infused intravenously, and the target Hct was 25% in AHH group.Before AHH(T0)and at 2, 4 and 8 h after AHH(T1-3), left ventricular systolic pressure(LVSP), left ventricular end-diastolic pressure(LVEDP), + dp/dtmax and -dp/dtmax were recorded, and blood samples from femoral veins were taken to determine the concentration of serum cardiac troponin I(cTnI)by ELISA.The rabbits were sacrificed at T3, and myocardial specimens were removed for microscopic examination of pathological changes with light microscope. Results Compared with group C, the serum cTnI concentration and LVEDP were significantly increased, LVSP and + dp/dt max were decreased at T1-3 in B and AHH groups, and -dp/dtmax at T1-3 in group B and -dp/dtmax at T3 in group AHH were decreased.Compared with group B, LVSP, + dp/dtmax and -dp/dtmaxwere significantly increased at T1-3, and no significant change was found in serum cTnI concentration and LVEDP in group AHH.There was no significant difference in the pathological changes between group B and group AHH. Conclusion AHH can not aggravate the early myocardial damage in severely burned rabbits. Key words: Hemodilution; Burns; Myocardial reperfusion injury

Renal hemodynamics, function, and oxygenation during cardiac surgery performed on cardiopulmonary bypass: a modeling study.

Acute kidney injury, a prevalent complication of cardiac surgery performed on cardiopulmonary bypass (CPB), is thought to be driven partly by hypoxic damage in the renal medulla. To determine the causes of medullary hypoxia during CPB, we modeled its impact on renal hemodynamics and function, and thus oxygen delivery and consumption in the renal medulla. The model incorporates autoregulation of renal blood flow and glomerular filtration rate and the utilization of oxygen for tubular transport. The model predicts that renal medullary oxygen delivery and consumption are reduced by a similar magnitude during the hypothermic (down to 28°C) phase of CPB. Thus, the fractional extraction of oxygen in the medulla, an index of hypoxia, is increased only by 58% from baseline. However, during the rewarming phase (up to 37°C), oxygen consumption by the medullary thick ascending limb increases 2.3‐fold but medullary oxygen delivery increases only by 33%. Consequently, the fractional extraction of oxygen in the medulla is increased 2.7‐fold from baseline. Thus, the renal medulla is particularly susceptible to hypoxia during the rewarming phase of CPB. Furthermore, autoregulation of both renal blood flow and glomerular filtration rate is blunted during CPB by the combined effects of hemodilution and nonpulsatile blood flow. Thus, renal hypoxia can be markedly exacerbated if arterial pressure falls below its target level of 50 mmHg. Our findings suggest that tight control of arterial pressure, and thus renal oxygen delivery, may be critical in the prevention of acute kidney injury associated with cardiac surgery performed on CPB.

Effect of Preoperative Autologous Blood Donation Coupled With Fluid Resuscitation on Transfusion Requirements Following Orthopedic Surgery

Background: Preoperative auto-blood donation has been shown to increase the likelihood of developing postoperative anemia following orthopedic surgery. This study was to assess the additive effect of intraoperative plus postoperative fluid resuscitation upon the relationship between preoperative donation and the frequency of postoperative transfusion. Methods: In this retrospective, single institution case-controlled study, hemoglobin levels, fluid administration, and incidence of transfusion were reviewed among 182 patients (91 donated blood preoperatively and 91 did not) undergoing total hip arthroplasty (THA) or total knee arthroplasty (TKA). Results: Thirty-two (35.2%) donors and 18 (19.8%) non-donors received transfusion for adjusted risk of 2.817 (1.301 - 6.100) among donors versus non-donors. Donors are more affected by the hemodilution effects associated with fluid infusion and are transfused earlier and more frequently than non-donors. Conclusion: Preoperative autologous donation and fluid administration increase the risk for receiving postoperative transfusion. J Hematol. 2015;4(2):157-163 doi: http://dx.doi.org/10.14740/jh208w

Intravitreal Ranibizumab versus Isovolemic Hemodilution in the Treatment of Macular Edema Secondary to Central Retinal Vein Occlusion: Twelve-Month Results of a Prospective, Randomized, Multicenter Trial

Purpose: This is a prospective, randomized, multicenter, investigator-initiated trial to evaluate the 12-month effectiveness of isovolemic hemodilution (IH) with prompt versus deferred intravitreal injections (IVI) of ranibizumab 0.5 mg for the treatment of macular edema secondary to early central retinal vein occlusion (CRVO). Methods: Eyes with macular edema due to CRVO having occurred not more than 8 weeks previously received either monthly ranibizumab IVI in combination with IH (group I, n = 28) or IH alone (group II, n = 30). From month 2 to 12, the patients in both groups could be treated with monthly intravitreal ranibizumab. The main outcome variables were gain of visual acuity and the course of central retinal thickness as measured with optical coherence tomography. Results: At 12 months, eyes in group I on average gained +28.1 (±19.3) letters compared to +25.2 (±20.9) letters in group II (p = 0.326). This result was achieved with significantly fewer injections in group II. Additionally, 30% of the eyes in group II did not need ranibizumab IVI during the 12 months of the trial. Conclusion: Ranibizumab IVI in addition to IH proved to be highly effective in increasing visual acuity and reducing macular edema secondary to CRVO. Initial IH in early CRVO may be a first treatment option in patients anxious about IVI.

Hemodilution for acute ischemic stroke.

Ischemic stroke involves focal hypoperfusion of the central nervous system. Hemodilution could theoretically improve perfusion to the affected area and, therefore, reduce infarct size. To assess the effects of hemodilution on clinical outcomes in patients with acute ischemic stroke. We searched the Cochrane Stroke Group Trials Register (February 2014), the Cochrane Central Register of Controlled Trials (Issue 1, 2014), MEDLINE (January 2008 to October 2013), and EMBASE (January 2008 to October 2013). We also searched trials registers, scanned reference lists, and contacted authors. We included randomized trials of hemodilution treatment in acute ischemic stroke, started within 72 hours …

The effect of serial in vitro haemodilution with maternal cerebrospinal fluid and crystalloid on thromboelastographic (TEG(®) ) blood coagulation parameters, and the implications for epidural blood patching.

Epidural blood patches may be used to treat post-dural puncture headache following accidental dural puncture in parturients. Their mode of action and the optimum volume of blood for injection remain controversial, with the interaction between injected blood and cerebrospinal fluid unknown. We aimed to establish the effects of serial haemodilution of whole blood with cerebrospinal fluid from 34 pregnant patients compared with serial haemodilution with Hartmann's solution, using the thromboelastogram. Haemodilution with either cerebrospinal fluid or Hartmann's solution had significant procoagulant and clot destabilising effects, enhanced with progressive haemodilution up to 30%. The effect of cerebrospinal fluid was greater compared with Hartmann's solution (p < 0.001). Cerebrospinal fluid led to a mean (95% CI) decrease in r-time by 2.4 (1.6-3.2) min, a decrease in k-time by 0.6 (0.4-0.8) min, an increase in alpha angle by 7.3 (5.5-9.0)°, and a decrease in maximum amplitude by 2.0 (0.6-3.4) mm. This may have implications for epidural blood patch, as success may be reduced near the time of dural puncture when cerebrospinal fluid leak is at its greatest, and large volumes of blood may be required to reduce haemodilution and clot destabilisation by cerebrospinal fluid. In addition, blood patching should be performed at the level of the dural puncture in order to ensure that the maximum volume of blood comes into contact with the cerebrospinal fluid.

Effect of obesity-related plasma hemodilution on serum tumor marker concentration in women.

We determined to investigate the effect of plasma hemodilution on tumor marker concentration in obese women. We collected the data for tumor markers (cancer-associated antigen 125 [CA125], carbohydrate antigen 19-9 [CA19-9], carcinoembryonic antigen [CEA] and α-fetoprotein) from 6917 healthy women who visited the health promotion center at the Chung-Ang University Hospital from 2003 to 2011. We used multivariate linear regression analysis and χ(2) -test for linear-by-linear association adjusting for age, alanine aminotransferase and creatinine to determine the association between the serum tumor marker concentrations, plasma volume, tumor marker mass, and body mass index (BMI). Higher BMI was significantly associated with higher plasma volume (P < 0.001 for trend). The lower concentrations of CA125 and CA19-9 were significantly associated with increasing BMI (P < 0.001). Serum concentration and mass of CEA and α-fetoprotein were increased with higher BMI in obese women (P < 0.001). CEA in women had the opposite result to that in men due to visceral fat in women. This study shows that we should consider the hemodilution effect in Asian obese women when interpreting serum tumor marker concentration in cancer screening.

Finally proving the maxim: quantifying the effect of hemodilution in prospective randomized control trial with blood donation as a model for hemorrhage

Ross, Samuel W. MD, MPH; Christmas, Britton A MD, FACS; Fischer, Peter E. MD, MS; Holway, Haley E. BS; Seymour, Rachel PhD; Heniford, Todd B MD, FACS; Sing, Ronald F. DO, FACS Author Information

Haemodilution for acute ischaemic stroke.

Ischaemic stroke interrupts the flow of blood to part of the brain. Haemodilution is thought to improve the flow of blood to the affected areas of the brain and thus reduce infarct size. To assess the effects of haemodilution in acute ischaemic stroke. We searched the Cochrane Stroke Group Trials Register (February 2014), the Cochrane Central Register of Controlled Trials (Issue 1, 2014), MEDLINE (January 2008 to October 2013) and EMBASE (January 2008 to October 2013). We also searched trials registers, scanned reference lists and contacted authors. For the previous version of the review, the authors contacted manufacturers and investigators in the field. Randomised trials of haemodilution treatment in people with acute ischaemic stroke. We included only trials in which treatment was started within 72 hours of stroke onset. Two review authors assessed trial quality and one review author extracted the data. We included 21 trials involving 4174 participants. Nine trials used a combination of venesection and plasma volume expander. Twelve trials used plasma volume expander alone. The plasma volume expander was plasma alone in one trial, dextran 40 in 12 trials, hydroxyethyl starch (HES) in five trials and albumin in three trials. Two trials tested haemodilution in combination with another therapy. Evaluation was blinded in 14 trials. Five trials probably included some participants with intracerebral haemorrhage. Haemodilution did not significantly reduce deaths within the first four weeks (risk ratio (RR) 1.10; 95% confidence interval (CI) 0.90 to 1.34). Similarly, haemodilution did not influence deaths within three to six months (RR 1.05; 95% CI 0.93 to 1.20), or death and dependency or institutionalisation (RR 0.96; 95% CI 0.85 to 1.07). The results were similar in confounded and unconfounded trials, and in trials of isovolaemic and hypervolaemic haemodilution. No statistically significant benefits were documented for any particular type of haemodiluting agents, but the statistical power to detect effects of HES was weak. Six trials reported venous thromboembolic events. There was a tendency towards reduction in deep venous thrombosis or pulmonary embolism or both at three to six months' follow-up (RR 0.68; 95% CI 0.37 to 1.24). There was no statistically significant increased risk of serious cardiac events among haemodiluted participants. The overall results of this review showed no clear evidence of benefit of haemodilution therapy for acute ischaemic stroke.These results are compatible with no persuasive beneficial evidence of haemodilution therapy for acute ischaemic stroke. This therapy has not been proven to improve survival or functional outcome.

The impact of haemodilution and bypass pump flow on cerebral oxygen desaturation during cardiopulmonary bypass - A comparison of two systems of cardiopulmonary bypass

To determine the influence of haemodilution, bypass flow rates and calculated oxygen delivery during cardiopulmonary bypass (CPB) with either a conventional CPB (C-CPB) circuit or a miniaturised (Mini-CPB) circuit on cerebral oxygen desaturation. The effect of minimal haemodilution with a Mini-CPB was investigated. Eighty patients scheduled for elective cardiac surgery. Oxygenated haemoglobin (O2Hb) and tissue oxygenation index (TOI) were measured with near-infrared spectroscopy (NIRS). The average indexed bypass pump flow was significantly lower with Mini-CPB. When combined with haemoglobin concentration, the average oxygen delivery was the same between groups. Patients in the C-CPB group had a greater duration and severity of cerebral desaturation to a level <20% below baseline values, but none reached the depth and duration of the cerebral desaturation associated with poor outcome. Cerebral oxygen desaturation with C-CPB was significantly associated with low flows during bypass, whereas desaturation with Mini-CPB was associated with low perioperative haemoglobin concentration.