The effect of hemodilution with albumin or Ringer's lactate on water balance and blood use in open-heart surgery

Safety and efficacy of cell-free and concentrated ascites reinfusion therapy (CART) in refractory ascites: Post-marketing surveillance results

We performed post-marketing surveillance to evaluate the safety and efficacy of cell-free and concentrated ascites reinfusion therapy (CART). In total, 356 CART sessions in 147 patients at 22 centers were performed. The most common primary disease was cancer (128 cases, 300 sessions). Mean amount of ascites collected was 3.7 L, and mean concentration ratio was 9.2. Mean amount of reinfused protein was 67.8 g (recovery rate, 72.0%). Performance status, dietary intake, urine volume, body weight and abdominal circumference were significantly improved after CART. Body temperature increased significantly, by 0.3°C on average. Concomitant steroids and/or NSAIDs use before reinfusion was significantly and negatively associated with increases in body temperature. Most adverse events were fever and chills. This study examined a large number of patients compared with previous studies, and showed that CART is an effective and relatively safe treatment for refractory ascites, such as malignant ascites.

Comparison of dextran 40 with albumin and Ringer's lactate as components of perfusion prime for cardiopulmonary bypass in patients undergoing myocardial revascularization

A major expense for the conduct of cardiopulmonary bypass in many institutions is the cost of 5% albumin. Potential advantages in using dextran 40 as the colloid component of the priming solution for cardiopulmonary bypass include decreased cost and less viscosity in the microcirculation. Possible disadvantages include bleeding and anaphylactic reactions.

From August 1985 to February 1986, 60 consecutive patients undergoing elective myocardial revascularization were prospectively randomized to receive either 5% albumin ( N = 29) or dextran 40 (N = 31) as the colloid component of the priming solution for cardiopulmonary bypass. Twenty matched patients also underwent revascularization with the prime consisting only of Ringer's lactate solution. There were no differences among the three groups for age, sex, size, crossclamp time, cardiopulmonary bypass time or number of coronary artery bypass grafts performed. In all three groups important postoperative changes were noted in platelet count, bleeding time, thrombin time, prothrombin time, fibrinogen and fibrin split products. Complement levels (C5a) were elevated in the dextran group (p = 0.03). Postoperative crystalloid (p = 0.04) and colloid (p = 0.0001 ) requirements were increased in the Ringer's lactate group and there was a significant weight gain (p = 0.0001). Colloid osmotic pressure was highest in the dextran group during (p = 0.0001) and after bypass (p = 0.001). There was no difference in clinical events and no hospital deaths.

In conclusion, we found dextran to be a safe colloid for use as prime in uncomplicated coronary artery bypass grafting patients. The cost of dextran prime was substantially less than for albumin prime. A purely crystalloid prime is discouraged because of a tendency for fluid retention.

Albumin administration is associated with acute kidney injury in cardiac surgery: a propensity score analysis

Introduction

The risk of acute kidney injury (AKI) with the use of albumin-containing fluids compared to starches in the surgical intensive care setting remains uncertain. We evaluated the adjusted risk of AKI associated with colloids following cardiac surgery.

Methods

We performed a retrospective cohort study of patients undergoing on-pump cardiac surgery in a tertiary care center from 2008 to 2010. We assessed crystalloid and colloid administration until 36 hours after surgery. AKI was defined by the RIFLE (risk, injury, failure, loss and end-stage kidney disease) risk and Acute Kidney Injury Network (AKIN) stage 1 serum creatinine criterion within 96 hours after surgery.

Results

Our cohort included 984 patients with a baseline glomerular filtration rate of 72 ± 19 ml/min/1.73 m². Twenty-three percent had a reduced left ventricular ejection fraction (LVEF), thirty-one percent were diabetics and twenty-three percent underwent heart valve surgery. The incidence of AKI was 5.3% based on RIFLE risk and 12.0% based on the AKIN criterion. AKI was associated with a reduced LVEF, diuretic use, anemia, heart valve surgery, duration of extracorporeal circulation, hemodynamic instability and the use of albumin, pentastarch 10% and transfusions. There was an important dose-dependent AKI risk associated with the administration of albumin, which also paralleled a higher prevalence of concomitant risk factors for AKI. To address any indication bias, we derived a propensity score predicting the likelihood to receive albumin and matched 141 cases to 141 controls with a similar risk profile. In this analysis, albumin was associated with an increased AKI risk (RIFLE risk: 12% versus 5%, P = 0.03; AKIN stage 1: 28% versus 13%, P = 0.002). We repeated this methodology in patients without postoperative hemodynamic instability and still identified an association between the use of albumin and AKI.

Conclusions

Albumin administration was associated with a dose-dependent risk of AKI and remained significant using a propensity score methodology. Future studies should address the safety of albumin-containing fluids on kidney function in patients undergoing cardiac surgery.

Acute Normovolemic Hemodilution

This article examines the technique of hemodilution and the consequences, benefits, efficacy, cost effectiveness, and future of acute normovolemic hemodilution.

Morbidity in hospitalized patients receiving human albumin: a meta-analysis of randomized, controlled trials

OBJECTIVE

To determine the effect of albumin administration on morbidity in acutely ill hospitalized patients.

DATA SOURCE

Computer searches of MEDLINE, EMBASE, and the Cochrane Library; hand searches of journals and Index Medicus; inquiries with investigators and fluid product suppliers; and examination of reference lists. No language or time period restrictions were adopted.

STUDY SELECTION

Randomized, controlled trials comparing the administration of albumin with that of crystalloid, no albumin, or lower-dose albumin.

DATA EXTRACTION

Two investigators independently extracted data. The primary endpoint for the meta-analysis was morbidity, defined as the incidence of complications, including death. Trial quality was evaluated by blinding, allocation concealment, presence of morbidity as a study endpoint, and individual patient crossover.

DATA SYNTHESIS

Seventy-one trials were included in the categories of surgery or trauma, burns, hypoalbuminemia, high-risk neonates, ascites, and other indications. The 3,782 randomized patients in the included trials experienced a total of 3,287 complications, including 515 deaths and 2,772 cardiovascular, gastrointestinal, hepatic, infectious, renal, respiratory, and other complications. Albumin significantly reduced overall morbidity, with a risk ratio of 0.92 (confidence interval [CI], 0.86-0.98). Control group albumin dose significantly affected the incidence of complications (p = .002). In 32 trials with no albumin administered to the control group, the risk ratio was 0.77 (CI, 0.67-0.88) compared with 0.89 (CI, 0.80-1.00) in 20 trials with control patients receiving low-dose albumin and 1.07 (CI, 0.96-1.20) in 19 trials with moderate-dose control group albumin.

CONCLUSIONS

Albumin reduces morbidity in acutely ill hospitalized patients. Concomitant administration of albumin in the control group can obscure the effects of albumin on clinical outcome in randomized trials.

Identifying Patients at Risk of Intraoperative and Postoperative Transfusion in Isolated CABG: Toward Selective Conservation Strategies

BACKGROUND

Allogeneic blood product use during cardiac operation is often reported to exceed 40% despite published guidelines and costly blood conservation strategies. We developed a predictive model, based on eight preoperative risk factors, of allogeneic blood product transfusion rates in patients undergoing a cardiac procedure.

METHODS

All 3,046 consecutive, isolated coronary artery bypass graft (CABG) procedures at a university hospital from 1995 to 1998 were included. A logistic regression model was created to identify independent predictors of allogeneic blood product transfusion. This model was validated using a prospective patient sample.

RESULTS

Overall use of allogeneic blood products was 23% with a crude operative mortality of 2.1%. In isolated, elective, first-time CABG cases, 16.9% received allogeneic blood products. Independent predictors of blood product usage in CABG patients were preoperative hemoglobin 12.0 or less, emergent operation, renal failure, female sex, age 70 years or older, left ventricular ejection fraction 0.40 or less, redo procedure, and low body surface area. Prospective validation of this model on 2,117 consecutive isolated CABG patients demonstrated an observed-to-expected allogeneic blood product transfusion rate ratio of 1.06.

CONCLUSIONS

This internally validated logistic regression risk model is a sensitive and specific predictor of allogeneic blood product use in patients undergoing isolated CABG. Utilization of this model allows for preoperative risk stratification and may allow for more rational resource allocation of costly blood conservation strategies and blood bank resources.

Albumin administration--what is the evidence of clinical benefit? A systematic review of randomized controlled trials

BACKGROUND AND OBJECTIVE

The advantages of albumin over less costly alternative fluids continue to be debated. Meta-analyses focusing on survival have been inconclusive, and other clinically relevant end-points have not been systematically addressed. We sought to determine whether albumin confers significant clinical benefit in acute illness compared with other fluid regimens.

METHODS

Database searches (MEDLINE, EMBASE, Cochrane Library) and other methods were used to identify randomized controlled trials comparing albumin with crystalloid, artificial colloid, no albumin or lower-dose albumin. Major findings for all end-points were extracted and summarized. A quantitative meta-analysis was not attempted.

RESULTS

Seventy-nine randomized trials with a total of 4755 patients were included. No significant treatment effects were detectable in 20/79 (25%) trials. In cardiac surgery, albumin administration resulted in lower fluid requirements, higher colloid oncotic pressure, reduced pulmonary oedema with respiratory impairment and greater haemodilution compared with crystalloid and hydroxyethylstarch increased postoperative bleeding. In non-cardiac surgery, fluid requirements, and pulmonary and intestinal oedema were decreased by albumin compared with crystalloid. In hypoalbuminaemia, higher doses of albumin reduced morbidity. In ascites, albumin reduced haemodynamic derangements, morbidity and length of stay and improved survival after spontaneous bacterial peritonitis. In sepsis, albumin decreased pulmonary oedema and respiratory dysfunction compared with crystalloid, while hydroxyethylstarch induced abnormalities of haemostasis. Complications were lowered by albumin compared with crystalloid in burn patients. Albumin-containing therapeutic regimens improved outcomes after brain injury.

CONCLUSIONS

Albumin can bestow benefit in diverse clinical settings. Further trials are warranted to delineate optimal fluid regimens, in particular indications.

Effects of preoperative intentional hemodilution on the extravasation rate of albumin and fluid

OBJECTIVE

To evaluate the effects of preoperative intentional hemodilution with 4% albumin solution on the extravasation rate of intravascular albumin and fluid in surgical patients.

DESIGN

A prospective, randomized, clinical study.

SETTING

University teaching hospital.

PATIENTS

Two groups (control group [group 1] and hemodiluted group [group 2]) of 13 healthy patients were studied during a long-term (>4 hrs) surgical procedure.

INTERVENTIONS

Autologous technetium-99m (99mTc)-labeled red blood cells and indium-oxine ((111)In)-labeled human serum albumin were injected intravenously during anesthesia at T = 0 min in the two groups for the determination of total blood volume and albumin diffusion space, respectively. In addition, body tetrapolar electrical impedance was used to assess extracellular fluid volume. In the hemodiluted group (group 2), 15 mL/kg of blood was withdrawn over 30 mins (T = 20 mins to T = 50 mins) and simultaneously replaced by an equal volume of 4% albumin solution (0.6 g/kg).

MEASUREMENTS AND MAIN RESULTS

The albumin diffusion space, the colloid oncotic pressure, the plasma albumin concentration and the electrical impedance were measured before (T = 10 mins) and after (T = 60, 120, and 240 mins) hemodilution. Urine was collected from T = 10 mins to T = 240 mins. The total blood volume was calculated at T = 10 mins. No differences in the initial values were found between the two groups. In group 2, hemodilution (hematocrit 30 +/- 3%) resulted in a steeper increase in the albumin diffusion space (p < .05) and a progressive decrease in the body electrical impedance (p < .05). The extravasation rate of albumin was 0.052 +/- 0.007 mL/kg/min in group 2 vs. 0.038 +/- 0.020 mL/kg/min in group 1 (p < .05). The value of calculated plasma volume at T = 0 min did not shown any difference between the two groups. This value was then lower than expected in group 2, corresponding to a loss of plasma volume of >3 mL/kg. Urine output was significantly lower in group 2 than in group 1 (0.7 +/- 0.4 vs. 1.4 +/- 1.0 mL/min, respectively; p < .05). A comparable decrease in colloid oncotic pressure and in plasma albumin concentration was observed in both groups.

CONCLUSIONS

These results suggest that preoperative hemodilution using 4% albumin on a 1:1 volume basis for blood substitution during a prolonged surgical procedure with reduced blood losses enhances the extravasation rate of albumin and fluid to the interstitial tissues, impeding the maintenance of isovolemia. These findings support the use of a volume of infused colloid solution higher than that of withdrawn blood during preoperative hemodilution.

[Indications and role of albumin for vascular loading in the operating room]

Prospective clinical studies on albumin and non human colloids, administered peroperatively, were analysed. Only those with a level of evidence I or II were considered. On the basis of the cost-effectiveness ratio, albumin should not be the first choice treatment for peroperative plasma volume expansion. Low molecular weight hydroxyethylstarch is as efficient for restoration and maintenance of volaemia and colloid osmotic pressure. Albumin is administered when other colloids are contra-indicated or when their upper limit of volume has been reached.

Benefit from combining blood conservation measures in cardiac operations

Conventional blood conservation techniques have been insufficient to decrease transfusion needs in increasingly complex cardiac operations. To evaluate combinations of conservation techniques, 300 patients were divided into three equal groups. Group 1 had intraoperative autotransfusion and return of mediastinal drainage for 4 hours postoperatively. Group 2 had these measures plus intraoperative plasmapheresis. These two groups were given a transfusion for a hematocrit of less than 0.21 on cardiopulmonary bypass. Group 3 was treated with the same measures as group 2 but did not receive transfusions while on pump unless the hematocrit decreased to less than 0.15. The percentage of patients in each group given transfusions in the operating room was 34% in group 1, 28% in group 2, and 7% in group 3 (p less than 0.05). The percentage of all patients receiving transfusions during hospitalization was 68% in group 1, 36% in group 2 (p less than 0.05), and 18% in group 3 (p less than 0.05). Average total units transfused were 2.16 +/- 0.25 in group 1, 0.7 +/- 0.15 in group 2 (p less than 0.05), and 0.37 +/- 0.07 in group 3 (p less than 0.05). The perioperative morbidity rates including myocardial infarctions and strokes were similar. There were no deaths in group 3. Combining complementary conservation measures is effective in reducing homologous blood transfusions, and the need for transfusion can be safely reduced by allowing profound hemodilution during bypass.

Limiting the usage of blood products in cardiovascular surgery

We studied the effect of the initiation of a five part program of blood component conservation on blood product utilization in patients undergoing major cardiovascular surgery. We encouraged physicians and nurses to adhere to a set of guidelines that would limit the exposure of these patients to complications associated with blood product administration. Through this effort the amounts of packed red cells, fresh frozen plasma, platelets, and cryoprecipitate used were markedly reduced. After the start of the conservation program, overall blood product usage was reduced 29% despite a 46% increase in the surgical caseload, and there was a 53% decrease in the amount of donor exposure (units of individual blood products administered) per patient.

Albumin utilization in a university hospital

The inappropriate use of high-priced agents such as human serum albumin significantly contributes to the rising cost of medical care. A utilization review was conducted at the University of Michigan Hospital in order to identify the appropriateness of use of this agent. Criteria were developed and prescribing was retrospectively evaluated for 81 patients. Of the 935 units administered to these patients, 692 (74 percent) were judged to be inappropriate. This inappropriate use accounted for a projected annual expenditure of nearly $281,000. Interventions have previously demonstrated success in improving prescribing.

Transcapillary fluid balance in subcutaneous tissue of patients undergoing aortocoronary bypass with extracorporeal circulation

Colloid osmotic pressure in plasma (COPpl) from a cubital vein and in interstitial fluid (COPif) in the subcutaneous tissue at heart level, and interstitial fluid pressure (Pif) at the same level, were measured in 18 healthy subjects and in 28 patients requiring aortocoronary bypass. Interstitial fluid was collected via subcutaneously implanted double nylon wicks and Pif was measured with the 'wick-in-needle' technique. Measurements were made preoperatively and 1 1/2 to 8 hours (mean 4 hours) after termination of extracorporeal circulation. Pif rose to 2.3 mmHg above the pre-bypass level. COPpl concomitantly fell from 22.2 to 14.4 and COPif from 12.4 to 10.1 mmHg. These changes were statistically significant. Although the relatively large COPpl drop resulted in a net rise of 3.2 mmHg in filtration pressure, the incidence of pulmonary complications was low and no subcutaneous edema was discernible. The fall in COPif and rise in Pif may be regarded as important edema-preventing mechanisms.

Determinants of blood utilization during myocardial revascularization

Blood transfusion during cardiac surgical procedures has steadily decreased, but little information is available regarding the factors that determine its necessity or amount. To determine the predictors of blood utilization during myocardial revascularization, 441 consecutive patients undergoing primary myocardial revascularization were studied. Forty-four patients (10%) received blood during hospitalization with a mean transfusion of 0.3 +/- 1.4 units per patient. Age, sex, weight, body surface area, preoperative hematocrit, blood volume, and red blood cell volume were examined univariately for trends. All demonstrated a statistically significant trend for both need and amount of transfusion (p less than 0.001). Neither number of grafts nor duration of cardiopulmonary bypass demonstrated statistically significant trends. All univariately significant factors were evaluated by multivariate logistic regression analysis. Red cell volume was the best predictor of the need for transfusion (p less than 0.001), followed by age. No other factors improved predictive capabilities. We conclude that preoperative red cell mass and age are the principal determinants of the need for and quantity of blood transfused during myocardial revascularization. Use of this information may greatly improve the efficiency of ordering blood before operation.

Hydroxyethyl starch versus albumin for colloid infusion following cardiopulmonary bypass in patients undergoing myocardial revascularization

Hydroxyethyl starch or hetastarch (HES), a synthetic colloid for intravascular volume expansion, was compared with albumin after coronary artery operations in 30 patients (15 in each study group). Cardiac index, atrial pressures, heart rate, and systolic blood pressure were similar in both groups. There were no differences in cumulative urine output at 24 hours or in weight change during the first 7 postoperative days. Values for colloid osmotic pressure, as well as for this variable minus left atrial pressure, were lowest soon after bypass but returned to baseline within 4 hours, with no difference between groups in the first 24 hours or 7 days after operation. Coagulation variables were similar, but prothrombin and partial thromboplastin times were higher 12 hours postoperatively and fibrinogen level was lower 7 days postoperatively in the patients receiving HES. There was no clinical evidence of excessive bleeding, although cumulative chest drainage at 12 and 24 hours was slightly higher in the HES group (p = 0.09 and 0.08, respectively). We conclude that hetastarch is a safe and effective colloid to use following coronary operations.

Effect of albumin and mannitol on organ blood flow, oxygen delivery, water content, and renal function during hypothermic hemodilution cardiopulmonary bypass

The present study was designed to determine if the addition of albumin or mannitol to the priming solution of the pump oxygenator would diminish edema in organs, without diminishing some of the beneficial effects of hemodilution on blood flow and renal function. Tissue blood flow (15 mu spheres), water content, and renal clearances were determined in 8 animals during cardiopulmonary bypass. A 2(2) factorial, completely fixed experimental design was used. All animals were placed on cardiopulmonary bypass with hemodilution (hematocrit 25 +/- 2%) and hypothermia (25 degrees +/- 1 degree C). Albumin decreased flow to the midmyocardium of the left ventricle and to the spleen, and increased flow to the inner cortex of the kidney. Albumin caused decreased urine flow and decreased urine sodium, and also diminished renal osmolar, sodium, and free-water clearances. both mannitol and albumin decreased lung water. Mannitol decreased water content of the outer renal cortex, and decreased flow to the inner cortex and medulla of the kidney and to the spleen. Mannitol had no significant effect on urine flow, renal plasma flow, or renal clearances. Neither albumin nor mannitol had any effect on water content of the intestine, stomach, liver, or myocardium where the greatest accumulation of water occurs with hemodilution. The effect of albumin on renal function is potentially deleterious during cardiopulmonary bypass because it decreases urine flow, and osmolar and free-water clearance.

Blood conservation techniques

Increasing numbers of operations requiring cardiopulmonary bypass have been accompanied by greater demands for blood resources. Improved techniques of blood conservation have diminished the average blood requirements per operation and have increased the percent of operations that can be done without homologous blood. The conservation of blood can be planned according to each patient's requirements. The techniques include preoperative blood donation, intraoperative withdrawal of blood, reinfusion of oxygenator blood, autotransfusion of blood after heparin neutralization, autotransfusion after wound closure, and hemodilution. The availability of techniques for filtration, centrifugation, and washing of blood have improved the safety of autotransfusion. The techniques that gives the best cost/benefit ratio appear to be preoperative withdrawal of blood, reinfusion of centrifuged oxygenator contents, and reinfusion of filtered blood from chest drainage.

Pulmonary oxygenation, central haemodynamics and glomerular filtration following cardiopulmonary bypass with colloid or non-colloid priming solution

Plasma colloid osmotic pressure (COP), blood erythrocyte volume fraction (B-EVF), arterial oxygen tension at an inspired oxygen concentration of 30% (PaO2 (FIO2 0.3)), cardiac index, stroke volume, arterial mean pressure, left atrial mean pressure, pulmonary av-difference of oxygen (Ca-v O2) and creatinine clearance were studied in 16 patients during isolated aortic valve replacement. The patients were divided into two groups with different priming solutions in the oxygenator. In the non-colloid group 2,000 ml of Ringerdex was used, while the colloid group had 1,600 ml of Ringerdex and 400 ml of albumin 20% (80 g). COP differed significantly between the groups (p less than 0.01) during and for 1 hour after bypass. The greatest reductions were 56% and 30%, respectively. Haemodilution (los B-EVF) was of longer duration in the colloid group. No differences between the groups were found with respect to pulmonary oxygenation, myocardial behaviour or glomerular filtration rate. Cardiopulmonary bypass produced no changes in cardiac index, stroke volume, arterial mean pressure, left atrial mean pressure, Ca-v O2 or creatinine clearance in either of the groups. PaO2 (FIO2 0.3) remained unchanged in the non-colloid group and showed a small but significant reduction (p less than 0.01) in the colloid group. No positive effects of a colloid prime were demonstrated.

The use of blood and blood components in 1,769 patients undergoing open-heart surgery

There has been a decrease in the use of whole blood and red cell transfusions during and after open-heart operations in the greater Kansas City area from an average of slightly more than 9 units per patient from 1969 through 1971, to just over 3 units per patient from 1975 through 1977. In 1977, 1,256 patients, or 71% of 1,769 patients, underwent coronary artery bypass exclusively and had an average transfusion utilization of 2.6 units. All other open-heart operations averaged 4.7 units per patient. Hemodilution and the acceptance of hematocrits between 25 and 30% in open-heart operations are probably the main factors responsible for lower transfusion use per patient, while the increased proportion of patients undergoing coronary artery bypass accounts for a further decrease in the average amount of blood used per patient. It is of note that blood transfused to patients having an open-heart operation was not significantly fresher than blood for routine use, yet hemostasis was not a problem as evidenced by the small use of fresh-frozen plasma in 67 patients (3.8%) and platelet concentrates in 42 patients (2.4%).