Perioperative fluid management for adult cardiac surgery: network meta-analysis pooling on twenty randomised controlled trials

BACKGROUND

The aim of this study was to evaluate colloids and crystalloids used in perioperative fluid therapy for cardiac surgery patients to further investigate the optimal management strategies of different solutions.

METHOD

RCTs about adult surgical patients allocated to receive perioperative fluid therapy for electronic databases, including Ovid MEDLINE, EMBase, and Cochrane Central Register of Controlled Trials, were searched up to February 15, 2023.

RESULTS

None of the results based on network comparisons, including mortality, transfuse PLA, postoperative chest tube output over the first 24 h following surgery, and length of hospital stay, were statistically significant. Due to the small number of included studies, the results, including acute kidney injury, serum creatinine, serum microglobulin, and blood urea nitrogen, are from the direct comparison. For transfusion of RBCs, significant differences were observed in the comparisons of 3% gelatine vs. 6% HES 200/0.5, 4% albumin vs. 5% albumin, 4% gelatine vs. 5% albumin, 5% albumin vs. 6% HES 200/0.5, and 6% HES 130/0.4 vs. 6% HES 200/0.5. In transfusion of FFP, significant differences were observed in comparisons of 3% gelatine vs. 4% gelatine, 3% gelatine vs. 6% HES 200/0.5, 5% albumin vs. 6% HES 200/0.5, 4% gelatine vs. 5% albumin, 4% gelatine vs. 6% HES 200/0.4, and 6% HES 130/0.4 vs. 6% HES 200/0.5. For urinary output at 24 h after surgery, the results are deposited in the main text.

CONCLUSION

This study showed that 3% gelatin and 5% albumin can reduce the transfuse RBC and FFP. In addition, the use of hypertonic saline solution can increase urine output, and 5% albumin and 6% HES can shorten the length of ICU stay. However, none of the perioperative fluids showed an objective advantage in various outcomes, including mortality, transfuse PLA, postoperative chest tube output over the first 24 h following surgery, and length of hospital stay. The reliable and sufficient evidences on the injury of the kidney, including acute kidney injury, serum creatinine, serum microglobulin, and blood urea nitrogen, was still lacking. In general, perioperative fluids had advantages and disadvantages, and there were no evidences to support the recommendation of the optimal perioperative fluid for cardiac surgery.

Intravenous albumin in cardiac and vascular surgery: a systematic review and meta-analysis

BACKGROUND

Intravenous albumin is commonly utilised in cardiovascular surgery for priming of the cardiopulmonary bypass circuit, volume replacement, or both, although the evidence to support this practice is uncertain. The aim was to compare i.v. albumin with synthetic colloids and crystalloids for paediatric and adult patients undergoing cardiovascular surgery for all-cause mortality and other perioperative outcomes.

METHODS

A systematic review and meta-analysis of randomised controlled trials (RCTs) of i.v. albumin compared with synthetic colloids and crystalloids on the primary outcome of all-cause mortality was conducted. Secondary outcomes included renal failure, blood loss, duration of hospital or intensive care unit stay, cardiac index, and blood component use; subgroups were analysed by age, comparator fluid, and intended use (priming, volume, or both). We searched MEDLINE, Embase, and Cochrane Central Register of Controlled Trials (CCRT) from 1946 to November 23, 2022.

RESULTS

Of 42 RCTs, mortality was assessed in 15 trials (2711 cardiac surgery patients) and the risk difference was 0.00, 95% confidence interval (CI) -0.01 to 0.01, I2=0%. Among secondary outcomes, i.v. albumin resulted in smaller fluid balance, mean difference -0.55 L, 95% CI -1.06 to -0.4, I2=90% (nine studies, 1975 patients) and higher albumin concentrations, mean difference 7.77 g L-1, 95% CI 3.73-11.8, I2=95% (six studies, 325 patients).

CONCLUSIONS

Intravenous albumin use was not associated with a difference in morbidity and mortality in patients undergoing cardiovascular surgery, when compared with comparator fluids. The lack of improvement in important outcomes with albumin and its higher cost suggests it should be used restrictively.

SYSTEMATIC REVIEW PROTOCOL

PROSPERO; CRD42020171876.

The comparison of albumin and 6% hydroxyethyl starches (130/0.4) in cardiac surgery: a meta-analysis of randomized controlled clinical trials

Background

Fluid administration is a key tool in the maintenance of normovolemia in patients with cardiac surgery. The trials that evaluated the safety of 6% hydroxyethyl starch (HES) 130/0.4 in cardiac surgical patients were inconsistent. It is necessary to compare the efficacy and safety of albumin and 6% HES (130/0.4).

Method

We searched for the randomized controlled clinical trials that compared human albumin with 6% HES (130/0.4) in cardiac surgery in PubMed, Cochrane, and Embase.

Results

Ten studies involved a total of 1567 patients were included in our meta-analysis. For the efficiency, there was no difference in total volume of infusion between compared groups [P = 0.64, Fixed Effect Model (FEM): standardized mean difference (SMD) = 0.04, 95% confidence interval (CI) (− 0.12, 0.20)]. As for safety, the albumin show more risk than hydroxyethyl starch 130/0.4 in blood loss [P = 0.02, FEM: SMD: 0.22, 95% CI (0.03, 0.41)]. There was no difference in the frequency of transfusions (P = 0.20, RR = 1.11; 95% CI (0.95, 1.27)) between the two groups. No difference was observed for the days in intensive care unit [P = 0.05, FEM: SMD = − 0.18, 95% CI (− 0.36, 0.00)], and the days in hospital [P = 0.32, FEM: SMD = − 0.11, 95% CI (− 0.32, 0.10)]. Furthermore, both the incidence of AKI, RRT, and mortality were comparable in the two groups.

Conclusion

This study provided evidence that the 6% HES (130/0.4) might be the substitute for HA, which reduced the economic burden for patients with cardiac surgery. However, the effect of 6% HES (130/0.4) and HA on AKI still needs to be further studied.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12893-021-01340-x.

Safety and efficacy of tetrastarches in surgery and trauma: a systematic review and meta-analysis of randomised controlled trials

BACKGROUND

Hydroxyethyl starch (HES) 130 is a frequently used fluid to replace intravascular losses during surgery or trauma. In the past years, several trials performed in critically ill patients have raised questions regarding the safety of this product. Our aim in this meta-analysis was to evaluate the safety and efficacy of 6% HES during surgery and in trauma.

METHODS

This systematic review and meta-analysis was registered at PROSPERO (CRD42018100379). We included 85 fully published articles from 1980 to June 2018 according to the protocol and three additional recent articles up to June 2020 in English, French, German, and Spanish reporting on prospective, randomised, and controlled clinical trials applying volume therapy with HES 130/0.4 or HES 130/0.42, including combinations with crystalloids, to patients undergoing surgery. Comparators were albumin, gelatin, and crystalloids only. A meta-analysis could not be performed for the two trauma studies as there was only one study that reported data on endpoints of interest.

RESULTS

Surgical patients treated with HES had lower postoperative serum creatinine (P<0.001) and showed no differences in renal dysfunction, renal failure, or renal replacement therapy. Although there was practically no further difference in the colloids albumin or gelatin, the use of HES improved haemodynamic stability, reduced need for vasopressors (P<0.001), and decreased length of hospital stay (P<0.001) compared with the use of crystalloids alone.

CONCLUSIONS

HES was shown to be safe and efficacious in the perioperative setting. Results of the present meta-analysis suggest that when used with adequate indication, a combination of intravenous fluid therapy with crystalloids and volume replacement with HES as colloid has clinically beneficial effects over using crystalloids only.

Effect and safety of 4% albumin in the treatment of cardiac surgery patients: study protocol for the randomized, double-blind, clinical ALBICS (ALBumin In Cardiac Surgery) trial

Background

In cardiac surgery with cardiopulmonary bypass (CPB), large amounts of fluids are administered. CPB priming with crystalloid solution causes marked hemodilution and fluid extravasation. Colloid solutions may reduce fluid overload because they have a better volume expansion effect than crystalloids. The European Medicines Agency does not recommend the use of hydroxyethyl starch solutions (HES) due to harmful renal effects. Albumin solution does not impair blood coagulation but the findings on kidney function are conflicting. On the other hand, albumin may reduce endothelial glycocalyx destruction and decrease platelet count during CPB. No large randomized, double-blind, clinical trials have compared albumin solution to crystalloid solution in cardiac surgery.

Methods/design

In this single-center, double-blind, randomized controlled trial comprising 1386 adult cardiac surgery patients, 4% albumin solution will be compared to Ringer’s acetate solution in CPB priming and volume replacement up to 3200 mL during surgery and the first 24 h of intensive care unit stay. The primary efficacy outcome is the number of patients with at least one major adverse event (MAE) during 90 postoperative days (all-cause death, acute myocardial injury, acute heart failure or low output syndrome, resternotomy, stroke, major arrhythmia, major bleeding, infection compromising post-procedural rehabilitation, acute kidney injury). Secondary outcomes are total number of MAEs, incidence of major adverse cardiac events (MACE; cardiac death, acute myocardial injury, acute heart failure, arrhythmia), amount of each type of blood product transfused (red blood cells, fresh frozen plasma, platelets), total fluid balance at the end of the intervention period, total measured blood loss, development of acute kidney injury, days alive without mechanical ventilation in 90 days, days alive outside intensive care unit at 90 days, days alive at home at 90 days, and 90-day mortality.

Discussion

The findings of this study will provide new evidence regarding efficacy and safety of albumin solution in adult patients undergoing cardiac surgery with CPB.

Trial registration

EudraCT (clinicaltrialsregister.eu) 2015–002556-27 Registered 11 Nov 2016 and ClinicalTrials.gov NCT02560519. Registered 25 Sept 2015.

Postoperative Acute Kidney Injury and Blood Product Transfusion After Synthetic Colloid Use During Cardiac Surgery

OBJECTIVES

This study assessed the effect of 2 types of hydroxyethyl starches (HES) on renal integrity and blood transfusion in cardiac surgery patients.

DESIGN

Retrospective investigation.

SETTING

Patients from a single tertiary medical center.

PARTICIPANTS

Inclusion criteria included coronary artery bypass graft (CABG) and/or valve surgery that included cardiopulmonary bypass with aortic cross-clamping.

INTERVENTIONS

Intraoperative HES and blood product administration.

MEASUREMENTS AND MAIN RESULTS

The study comprised 1,265 patients who met inclusion criteria. Of these patients, 70% received HES, and of these, 47% received<1,000 mL and 53% received≥1,000 mL. There was no difference in the development of acute kidney injury between the 2 groups. A parsimonious propensity model for colloids showed that combined CABG and valve surgery were less likely to be associated with HES administration than was CABG alone (OR 0.68, confidence interval [CI] 0.46-0.97; p = 0.04). Intra-aortic balloon pump use was less likely to be associated with HES administration (OR 0.57, CI 0.38-0.86; p = 0.007). Patients with chronic kidney disease, stages 3 to 5, were less likely to receive HES, with an OR of 0.56 (CI 0.38-0.84; p = 0.004); 0.51 (CI 0.20-1.33; p = 0.170); and 0.23 (CI 0.12-0.44; p<0.0001), respectively, for each stage. No difference was noted in red blood cell transfusion. However, fresh frozen plasma, cryoprecipitate, and platelet transfusions were significantly higher with larger volumes of HES, with an OR of 2.03 (CI 1.64-2.52; p<0.001); 1.60 (CI 1.30-1.97; p<0.000); and 1.62 (CI 1.21-2.15; p = 0.006), respectively. No differences in surgical mortality were found between the colloid and noncolloid groups.

CONCLUSIONS

This study showed no association of postoperative acute kidney injury and red blood cell transfusion between the colloid and noncolloid groups. Although the complication rate was higher with HES administration, there was no difference in surgery mortality between the 2 groups.

Effects of 6% hydroxyethyl starch 130/0.4 on postoperative blood loss and kidney injury in off-pump coronary arterial bypass grafting: A retrospective study

We retrospectively evaluated the effects of 6% hydroxyethyl starch (HES) 130/0.4 on postoperative blood loss and acute kidney injury (AKI) in patients undergoing off-pump coronary artery bypass grafting (OPCAB).Electronic medical records of 771 patients who underwent OPCAB in our hospital between July 2012 and July 2014 were reviewed, and 249 patients without intraoperative HES-exposure (group NoHES) were matched 1:N with intraoperative HES-exposed 413 patients (group HES) based on propensity score. The effects of intraoperative HES on postoperative cumulative blood loss within the first 24 hours, need for bleeding-related reoperation, and occurrence of postoperative AKI (determined by KDIGO and RIFLE criteria) were analyzed.In our propensity score matched cohort, there were no significant differences between groups for median postoperative 24 hours blood loss (525 mL in group HES vs. 540 mL in group NoHES, P = .203) or need for bleeding-related reoperation (OR, 2.44; 95% confidence interval [CI], 0.64-9.34, P = .19). However, postoperative AKI (assessed by 2 criteria) occurred more frequently in group HES than in group NoHES (by KDIGO criteria: 10.7% vs. 3.6%; OR 3.43 [95% CI, 1.67-7.04]; P < .001 and by RIFLE criteria: 9.6% vs. 2%; OR 3.32 [95% CI, 1.34-8.24]; P = .01). The median volume of infused HES per patient weight was 16 mL/kg in group HES.In the patients undergoing OPCAB, intraoperative 6% HES 130/0.4 did not increase postoperative bleeding. However, renal safety remains a concern. Intraoperative use of HES should be determined cautiously during OPCAB.

Effect of perioperative crystalloid or colloid fluid therapy on hemorrhage, coagulation competence, and outcome: A systematic review and stratified meta-analysis

BACKGROUND

A meta-analysis concerning perioperative coagulation competence, hemorrhage, and outcome was conducted including the use of hydroxyethyl starches (HESs), dextran, or albumin versus administration of a crystalloid as control to assess the efficacy and safety of colloids and crystalloids for fluid administration during major elective surgery. Surgery was restricted to cardiovascular and noncardiovascular surgery, and HESs were stratified to HES 130/0.4 and HES 200/0.5.

METHODS

We searched Cochrane Central Register of Controlled Trials, MEDLINE, ISI Web of Science, EMBASE, conference proceedings, reference lists, and databases of ongoing trials.

RESULTS

Thirty one primary clinical randomized controlled trials included 2287 patients undergoing major surgery from January 2000 to August 2015. The perioperative changes in coagulation competence were measured by thromboelastography (TEG) maximum amplitude (MA) in 9 studies administering crystalloids versus HES and in 4 studies administering albumin versus HES. All studies but 1 disclosed increased reduction in TEG-MA following HES administration (P = 0.0001 and 0.0002). The total loss of blood was reported in 17 studies in which crystalloids were compared to HES and 12 studies reported increased blood loss after administration of HES (P < 0.003). When administering albumin versus HES, 6 studies reported reduced hemorrhage associated with albumin administration (P = 0.005). Reoperation was not significantly reduced by the use of crystalloids, but may be more frequent after HESs compared to albumin (P < 0.03). In this analysis, more patients admitted to administration of HESs were exposed to decrease coagulation competence, compared to perioperative crystalloids and albumin administration.

CONCLUSION

This stratified meta-analysis showed that increased blood loss was found in noncardiovascular surgery among patients receiving HES compared with crystalloids, followed by a marked reduction in TEG-MA, and infusion of 3rd-generation HES products did not influence the results significantly.

The impact of hydroxyethyl starches in cardiac surgery: a meta-analysis

Introduction

Recent studies in septic patients showed that adverse effects of hydroxyethyl starches (HESs) possibly outweigh their benefits in severely impaired physiological haemostasis. It remains unclear whether this also applies to patient populations that are less vulnerable. In this meta-analysis, we evaluated the impact of various HES generations on safety and efficacy endpoints in patients undergoing cardiac surgery.

Methods

We searched the PubMed, Embase and Cochrane Central Register of Controlled Trials databases for randomised controlled trials (RCTs) in the English or German language comparing the use of HES to any other colloid or crystalloid during open heart surgery.

Results

Blood loss and transfusion requirements were higher for older starches with mean molecular weights more than 200 kDa compared to other volume substitutes. In contrast, this effect was not observed with latest-generation tetrastarches (130/0.4), which performed even better when compared to albumin (blood loss of tetrastarch versus albumin: standardised mean difference (SMD), −0.34; 95% CI, −0.63, −0.05; P = 0.02; versus gelatin: SMD, −0.06; 95% CI, −0.20, 0.08; P = 0.39; versus crystalloids: SMD, −0.05; 95% CI, −0.20, 0.10; P = 0.54). Similar results were found for transfusion needs. Lengths of stay in the intensive care unit or hospital were significantly shorter with tetrastarches compared to gelatin (intensive care unit: SMD, −0.10; 95% CI, −0.15, −0.05; P = 0.0002) and crystalloids (hospital: SMD, −0.52; 95% CI, −0.90, −0.14; P = 0.007).

Conclusions

In this meta-analysis of RCTs, we could not identify safety issues with tetrastarches compared with other colloid or crystalloid solutions in terms of blood loss, transfusion requirements or hospital length of stay in patients undergoing cardiac surgery. The safety data on coagulation with older starches raise some issues that need to be addressed in future trials.

Electronic supplementary material

The online version of this article (doi:10.1186/s13054-014-0656-0) contains supplementary material, which is available to authorized users.

Comparison of the effects of gelatin, Ringer's solution and a modern hydroxyl ethyl starch solution after coronary artery bypass graft surgery

OBJECTIVE

The aim of this study was to compare the effect of 6% hydroxyl ethyl starch solution with 4% gelatin and Ringer's solutions on the haemodynamic stability of patients after coronary artery bypass graft (CABG) surgery and immediately after discontinuation of cardiopulmonary bypass (CPB).

METHODS

This was a randomised, double-blind clinical trial of 92 patients who were candidates for on-pump CABG. After discontinuation of CPB, all patients were transferred to the intensive care unit (ICU) and divided randomly into three groups. The first group received Ringer's solution, the second group 4% gelatin, and the third 6% hydroxyl ethyl starch (HES) solution (Voluven). Haemodynamic parameters such as heart rate, mean arterial pressure, systolic blood pressure, diastolic blood pressure, central venous pressure, cardiac output and the presence of arrhythmias were documented.

RESULTS

The volume needed for maintaining normal blood pressure and central venous pressure in the range of 10-14 mmHg was less in the HES group than in the other groups. The volume was similar however in the gelatin and Ringer's groups in the first 24 hours after surgery. Urinary output in the first four and 24 hours after surgery were significantly higher in the HES group than in the other two groups. Mean creatinine levels were significantly lower in the HES group.

CONCLUSION

HES (6%) had a better volume-expanding effect than gelatin (4%) and Ringer's solutions, and its short-term effects on renal function were also better than gelatin and Ringer's solutions.

Colloids versus crystalloids for fluid resuscitation in critically ill patients

BACKGROUND

Colloid solutions are widely used in fluid resuscitation of critically ill patients. There are several choices of colloid, and there is ongoing debate about the relative effectiveness of colloids compared to crystalloid fluids.

OBJECTIVES

To assess the effects of colloids compared to crystalloids for fluid resuscitation in critically ill patients.

SEARCH METHODS

We searched the Cochrane Injuries Group Specialised Register (17 October 2012), the Cochrane Central Register of Controlled Trials (The Cochrane Library) (Issue 10, 2012), MEDLINE (Ovid) 1946 to October 2012, EMBASE (Ovid) 1980 to October 2012, ISI Web of Science: Science Citation Index Expanded (1970 to October 2012), ISI Web of Science: Conference Proceedings Citation Index-Science (1990 to October 2012), PubMed (October 2012), www.clinical trials.gov and www.controlled-trials.com. We also searched the bibliographies of relevant studies and review articles.

SELECTION CRITERIA

Randomised controlled trials (RCTs) of colloids compared to crystalloids, in patients requiring volume replacement. We excluded cross-over trials and trials involving pregnant women and neonates.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data and rated quality of allocation concealment. We analysed trials with a 'double-intervention', such as those comparing colloid in hypertonic crystalloid to isotonic crystalloid, separately. We stratified the analysis according to colloid type and quality of allocation concealment.

MAIN RESULTS

We identified 78 eligible trials; 70 of these presented mortality data.COLLOIDS COMPARED TO CRYSTALLOIDS: Albumin or plasma protein fraction - 24 trials reported data on mortality, including a total of 9920 patients. The pooled risk ratio (RR) from these trials was 1.01 (95% confidence interval (CI) 0.93 to 1.10). When we excluded the trial with poor-quality allocation concealment, pooled RR was 1.00 (95% CI 0.92 to 1.09). Hydroxyethyl starch - 25 trials compared hydroxyethyl starch with crystalloids and included 9147 patients. The pooled RR was 1.10 (95% CI 1.02 to 1.19). Modified gelatin - 11 trials compared modified gelatin with crystalloid and included 506 patients. The pooled RR was 0.91 (95% CI 0.49 to 1.72). (When the trials by Boldt et al were removed from the three preceding analyses, the results were unchanged.) Dextran - nine trials compared dextran with a crystalloid and included 834 patients. The pooled RR was 1.24 (95% CI 0.94 to 1.65). COLLOIDS IN HYPERTONIC CRYSTALLOID COMPARED TO ISOTONIC CRYSTALLOID: Nine trials compared dextran in hypertonic crystalloid with isotonic crystalloid, including 1985 randomised participants. Pooled RR for mortality was 0.91 (95% CI 0.71 to 1.06).

AUTHORS' CONCLUSIONS

There is no evidence from randomised controlled trials that resuscitation with colloids reduces the risk of death, compared to resuscitation with crystalloids, in patients with trauma, burns or following surgery. Furthermore, the use of hydroxyethyl starch might increase mortality. As colloids are not associated with an improvement in survival and are considerably more expensive than crystalloids, it is hard to see how their continued use in clinical practice can be justified.

Randomised trials of 6% tetrastarch (hydroxyethyl starch 130/0.4 or 0.42) for severe sepsis reporting mortality: systematic review and meta-analysis

PURPOSE

To assess the impact of 6% tetrastarch [hydroxyethyl starch (HES) 130/0.4 and 130/0.42] in severe sepsis patients. The primary outcome measure was 90-day mortality.

METHODS

A structured literature search was undertaken to identify prospective randomised controlled trials (RCTs) in adult patients with severe sepsis receiving 6% tetrastarch (of potato or waxy maize origin) as part of fluid resuscitation in comparison with other non-HES fluids after randomisation in the critical care setting. A systematic review and meta-analysis were performed.

RESULTS

Six RCTs were included (n = 3,033): three from 2012 (n = 2,913) had low risk of bias. Median tetrastarch exposure was 37.4 ml/kg (range 30-43 ml/kg). Ninety-day mortality was associated with tetrastarch exposure [relative risk (RR) 1.13; 95% confidence interval (CI) 1.02-1.25; p = 0.02] compared with crystalloid. The number needed to harm (NNH) was 28.8 (95 % CI 14.6-942.5). Publication bias and statistical heterogeneity (I(2) = 0%) were not present. Tetrastarch exposure was also associated with renal replacement therapy (p = 0.01; NNH 15.7) and allogeneic transfusion support (p = 0.001; NNH 9.9). No difference between groups was observed for 28-day mortality, for comparison with colloid as control, or for waxy maize-derived tetrastarch, but power was lacking. Overall mortality was associated with tetrastarch exposure (RR 1.13; 95% CI 1.02-1.25; p = 0.02).

CONCLUSIONS

In our analysis, 6% tetrastarch as part of initial fluid resuscitation for severe sepsis was associated with harm and, as alternatives exist, in our view should be avoided.

Colloid solutions for fluid resuscitation

BACKGROUND

Colloids are widely used in the replacement of fluid volume. However, doubts remain as to which colloid is best. Different colloids vary in their molecular weight and therefore in the length of time they remain in the circulatory system. Because of this, and their other characteristics, they may differ in their safety and efficacy.

OBJECTIVES

To compare the effects of different colloid solutions in patients thought to need volume replacement.

SEARCH METHODS

We searched the Cochrane Injuries Specialised Register (searched 1 December 2011), the Cochrane Central Register of Controlled Trials 2011, issue 4 (The Cochrane Library); MEDLINE (Ovid) (1948 to November Week 3 2011); EMBASE (Ovid) (1974 to 2011 Week 47); ISI Web of Science: Science Citation Index Expanded (1970 to 1 December 2011); ISI Web of Science: Conference Proceedings Citation Index-Science (1990 to 1 December 2011); CINAHL (EBSCO) (1982 to 1 December 2011); National Research Register (2007, Issue 1) and PubMed (searched 1 December 2011). Bibliographies of trials retrieved were searched, and for the initial version of the review drug companies manufacturing colloids were contacted for information (1999).

SELECTION CRITERIA

Randomised controlled trials comparing colloid solutions in critically ill and surgical patients thought to need volume replacement.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted the data and assessed the quality of the trials. The outcomes sought were death, amount of whole blood transfused, and incidence of adverse reactions.

MAIN RESULTS

Eighty-six trials, with a total of 5,484 participants, met the inclusion criteria. Quality of allocation concealment was judged to be adequate in 33 trials and poor or uncertain in the rest.Deaths were reported in 57 trials. For albumin or plasma protein fraction (PPF) versus hydroxyethyl starch (HES) 31 trials (n = 1719) reported mortality. The pooled relative risk (RR) was 1.06 (95% confidence interval (CI) 0.86 to 1.31). When the trials by Boldt were removed from the analysis the pooled RR was 0.90 (95% CI 0.68 to 1.20). For albumin or PPF versus gelatin, nine trials (n = 824) reported mortality. The RR was 0.89 (95% CI 0.65 to 1.21). Removing the study by Boldt from the analysis did not change the RR or CIs. For albumin or PPF versus dextran four trials (n = 360) reported mortality. The RR was 3.75 (95% CI 0.42 to 33.09). For gelatin versus HES 22 trials (n = 1612) reported mortality and the RR was 1.02 (95% CI 0.84 to 1.26). When the trials by Boldt were removed from the analysis the pooled RR was 1.03 (95% CI 0.84 to 1.27). RR was not estimable in the gelatin versus dextran and HES versus dextran groups.Forty-one trials recorded the amount of blood transfused; however, quantitative analysis was not possible due to skewness and variable reporting. Twenty-four trials recorded adverse reactions, with two studies reporting possible adverse reactions to gel and one to HES.

AUTHORS' CONCLUSIONS

From this review, there is no evidence that one colloid solution is more effective or safe than any other, although the CIs were wide and do not exclude clinically significant differences between colloids. Larger trials of fluid therapy are needed if clinically significant differences in mortality are to be detected or excluded.

Colloids versus crystalloids for fluid resuscitation in critically ill patients

BACKGROUND

Colloid solutions are widely used in fluid resuscitation of critically ill patients. There are several choices of colloid and there is ongoing debate about the relative effectiveness of colloids compared to crystalloid fluids.

OBJECTIVES

To assess the effects of colloids compared to crystalloids for fluid resuscitation in critically ill patients.

SEARCH METHODS

We searched the Cochrane Injuries Group Specialised Register (searched 16 March 2012), Cochrane Central Register of Controlled Trials 2011, issue 3 (The Cochrane Library), MEDLINE (Ovid) 1946 to March 2012, Embase (Ovid) 1980 to March 2012, ISI Web of Science: Science Citation Index Expanded (1970 to March 2012), ISI Web of Science: Conference Proceedings Citation Index-Science (1990 to March 2012), PubMed (searched 16 March 2012), www.clinical trials.gov and www.controlled-trials.com. We also searched the bibliographies of relevant studies and review articles.

SELECTION CRITERIA

Randomised controlled trials (RCTs) of colloids compared to crystalloids, in patients requiring volume replacement. We excluded cross-over trials and trials in pregnant women and neonates.

DATA COLLECTION AND ANALYSIS

Two authors independently extracted data and rated quality of allocation concealment. We analysed trials with a 'double-intervention', such as those comparing colloid in hypertonic crystalloid to isotonic crystalloid, separately. We stratified the analysis according to colloid type and quality of allocation concealment.

MAIN RESULTS

We identified 74 eligible trials; 66 of these presented mortality data.Colloids compared to crystalloids Albumin or plasma protein fraction - 24 trials reported data on mortality, including a total of 9920 patients. The pooled relative risk (RR) from these trials was 1.01 (95% confidence interval (CI) 0.93 to 1.10). When we excluded the trial with poor quality allocation concealment, pooled RR was 1.00 (95% CI 0.92 to 1.09). Hydroxyethyl starch - 21 trials compared hydroxyethyl starch with crystalloids, n = 1385 patients. The pooled RR was 1.10 (95% CI 0.91 to 1.32). Modified gelatin - 11 trials compared modified gelatin with crystalloid, n = 506 patients. The pooled RR was 0.91 (95% CI 0.49 to 1.72). (When the trials by Boldt et al were removed from the three preceding analyses, the results were unchanged.) Dextran - nine trials compared dextran with a crystalloid, n = 834 patients. The pooled RR was 1.24 (95% CI 0.94 to 1.65).Colloids in hypertonic crystalloid compared to isotonic crystalloid Nine trials compared dextran in hypertonic crystalloid with isotonic crystalloid, including 1985 randomised participants. Pooled RR was 0.91 (95% CI 0.71 to 1.06).

AUTHORS' CONCLUSIONS

There is no evidence from RCTs that resuscitation with colloids reduces the risk of death, compared to resuscitation with crystalloids, in patients with trauma, burns or following surgery. As colloids are not associated with an improvement in survival, and as they are more expensive than crystalloids, it is hard to see how their continued use in these patients can be justified outside the context of RCTs.

Colloid solutions for fluid resuscitation

BACKGROUND

Colloids are widely used in the replacement of fluid volume. However doubts remain as to which colloid is best. Different colloids vary in their molecular weight and therefore in the length of time they remain in the circulatory system. Because of this and their other characteristics, they may differ in their safety and efficacy.

OBJECTIVES

To compare the effects of different colloid solutions in patients thought to need volume replacement.

SEARCH METHODS

We searched the Cochrane Injuries Specialised Register (searched 1 Dec 2011), Cochrane Central Register of Controlled Trials 2011, issue 4 (The Cochrane Library); MEDLINE (Ovid) (1948 to November Week 3 2011); EMBASE (Ovid) (1974 to 2011 Week 47); ISI Web of Science: Science Citation Index Expanded (1970 to 1 Dec 2011); ISI Web of Science: Conference Proceedings Citation Index-Science (1990 to 1 Dec 2011); CINAHL (EBSCO) (1982 to 1 Dec 2011); National Research Register (2007, Issue 1) and PubMed (searched 1 Dec 2011). Bibliographies of trials retrieved were searched, and for the initial version of the review drug companies manufacturing colloids were contacted for information (1999).

SELECTION CRITERIA

Randomised controlled trials comparing colloid solutions in critically ill and surgical patients thought to need volume replacement.

DATA COLLECTION AND ANALYSIS

Two authors independently extracted the data and assessed the quality of the trials. The outcomes sought were death, amount of whole blood transfused, and incidence of adverse reactions.

MAIN RESULTS

Ninety trials, with a total of 5678 participants, met the inclusion criteria. Quality of allocation concealment was judged to be adequate in 35 trials and poor or uncertain in the rest.Deaths were obtained in 61 trials. For albumin or PPF versus hydroxyethyl starch (HES) 32 trials (n = 1769) reported mortality. The pooled relative risk (RR) was 1.07 (95% CI 0.87 to 1.32). When the trials by Boldt were removed from the analysis the pooled RR was 0.90 (95% CI 0.68 to 1.20). For albumin or PPF versus gelatin, nine trials (n = 824) reported mortality. The RR was 0.89 (95% CI 0.65 to 1.21). Removing the study by Boldt from the analysis did not change the RR or confidence intervals. For albumin or PPF versus Dextran four trials (n = 360) reported mortality. The RR was 3.75 (95% CI 0.42 to 33.09). For gelatin versus HES 25 trials (n = 1756) reported mortality and the RR was 1.03 (95% CI 0.84 to 1.26). When the trials by Boldt were removed from the analysis the pooled RR was 1.04 (95% CI 0.85 to 1.27). RR was not estimable in the gelatin versus dextran and HES versus dextran groups.Forty five trials recorded the amount of blood transfused, however quantitative analysis was not possible due to skewness and variable reporting. Twenty-four trials recorded adverse reactions, with two studies reporting possible adverse reactions to Gel and one to HES.

AUTHORS' CONCLUSIONS

From this review, there is no evidence that one colloid solution is more effective or safe than any other, although the confidence intervals are wide and do not exclude clinically significant differences between colloids. Larger trials of fluid therapy are needed if clinically significant differences in mortality are to be detected or excluded.

Colloids versus crystalloids for fluid resuscitation in critically ill patients

BACKGROUND

Colloid solutions are widely used in fluid resuscitation of critically ill patients. There are several choices of colloid and there is ongoing debate about the relative effectiveness of colloids compared to crystalloid fluids.

OBJECTIVES

To assess the effects of colloids compared to crystalloids for fluid resuscitation in critically ill patients.

SEARCH STRATEGY

We searched the Cochrane Injuries Group Specialised Register, CENTRAL (The Cochrane Library 2008, Issue 3), MEDLINE, EMBASE, ISI Web of Science: Science Citation Index Expanded (SCI-EXPANDED), ISI Web of Science: Conference Proceedings Citation Index-Science (CPCI-S), and The Controlled Trials metaRegister (www.controlled-trials.com). Reference lists of relevant studies and review articles were searched for further trials. The searches were last updated in September 2008.

SELECTION CRITERIA

Randomised controlled trials (RCTs) of colloids compared to crystalloids, in patients requiring volume replacement. We excluded cross-over trials and trials in pregnant women and neonates.

DATA COLLECTION AND ANALYSIS

Two authors independently extracted data and rated quality of allocation concealment. We analysed trials with a 'double-intervention', such as those comparing colloid in hypertonic crystalloid to isotonic crystalloid, separately. We stratified the analysis according to colloid type and quality of allocation concealment.

MAIN RESULTS

We identified 65 eligible trials; 56 of these presented mortality data.Colloids compared to crystalloidsAlbumin or plasma protein fraction - 23 trials reported data on mortality, including a total of 7754 patients. The pooled relative risk (RR) from these trials was 1.01 (95% confidence interval (95% CI) 0.92 to 1.10). When we excluded the trial with poor quality allocation concealment, pooled RR was 1.00 (95% CI 0.91 to 1.09). Hydroxyethyl starch - 17 trials compared hydroxyethyl starch with crystalloids, n = 1172 patients. The pooled RR was 1.18 (95% CI 0.96 to 1.44). Modified gelatin - 11 trials compared modified gelatin with crystalloid, n = 506 patients. The pooled RR was 0.91 (95% CI 0.49 to 1.72). (When the trials by Boldt et al were removed from the three preceding analyses, the results were unchanged.) Dextran - nine trials compared dextran with a crystalloid, n = 834 patients. The pooled RR was 1.24 (95% CI 0.94 to 1.65).Colloids in hypertonic crystalloid compared to isotonic crystalloidEight trials compared dextran in hypertonic crystalloid with isotonic crystalloid, including 1283 randomised participants. Pooled RR was 0.88 (95% CI 0.74 to 1.05).

AUTHORS' CONCLUSIONS

There is no evidence from RCTs that resuscitation with colloids reduces the risk of death, compared to resuscitation with crystalloids, in patients with trauma, burns or following surgery. As colloids are not associated with an improvement in survival, and as they are more expensive than crystalloids, it is hard to see how their continued use in these patients can be justified outside the context of RCTs.

A systematic review of third-generation hydroxyethyl starch (HES 130/0.4) in resuscitation: safety not adequately addressed

BACKGROUND

Hydroxyethyl starches (HES) are widely used for intravascular volume therapy in surgical, emergency, and intensive care patients. There are safety concerns with regard to coagulopathy, renal failure, pruritus, tissue storage, and mortality. Third-generation HES 130/0.4 is considered to have an improved risk profile. A common rationale for the use of HES is the belief that 3 to 4 times more crystalloid than colloid volume is needed to achieve similar hemodynamic end points. Our goal was to assess whether published studies on HES 130/0.4 resuscitation are sufficiently well designed to draw conclusions about the safety of this compound. In addition, we wanted to assess crystalloid-to-colloid fluid ratios in studies with goal-directed fluid regimen.

METHODS

Systematic review of randomized controlled trials in which HES 130/0.4 is used for resuscitation.

RESULTS

We identified 56 randomized controlled trials (RCTs) with HES 130/0.4 in. acute hypovolemia, mainly from the elective surgical setting (n = 45). Surgical studies were small-sized (median 25 patients in the HES groups, range 10 to 90) and of short duration (median 12 hours, range 0.5 to 144 hours). The median cumulative HES dose was 2465 mL (range 328 to 6229 mL), corresponding to 35 mL/kg in a 70-kg patient, the daily dose limit being 50 mL/kg. End points mostly addressed variable surrogate outcomes. Sixty percent of control fluids were other HES solutions, gelatins, or dextran, which have a similar risk profile. Without exception, these studies were not designed for clinically important safety outcomes, primarily because they were too small, used mostly inadequate control fluids, and had inappropriately short observation periods. Therefore, and also because of heterogeneity of patient groups and outcome definitions, results from these studies cannot be pooled. These studies do not allow any conclusion about the safety of HES 130/0.4. There is a common belief that 3 to 4 times more crystalloid than colloid volume is necessary to achieve similar hemodynamic effects. We found a considerably lower ratio in surgical studies (mean 1.8, SD 0.1).

CONCLUSIONS

In summary, the extent of fluid load reduction that can be achieved by HES 130/0.4 is overestimated. Use of older HES solutions may be associated with serious side effects, and clinicians should be aware that there is no convincing evidence that third-generation HES 130/0.4 is safe in surgical, emergency, or intensive care patients despite publication of numerous clinical studies.

Comparison of the effect of 6% hydroxyethyl starch and gelatine on cardiac and stroke volume index: a randomized, controlled trial after cardiac surgery

BACKGROUND AND AIMS

The objective of this study was to find out the effect of various doses of hydroxyethyl starch (HES), gelatine or Ringer's acetate on cardiac and stroke volume index after cardiac surgery.

MATERIAL AND METHODS

Three consecutive boluses (each 7 mL·kg(-1)) of either 6% HES 130/0.4, 4% gelatine, or Ringer's acetate solutions were administered to 45 patients postoperatively. The rate of infusions was adjusted according to haemodynamic measurements. Thereafter, infusion of the study solution (7 mL·kg(-1)) was continued for the following 12 hours. The total dose of study solution was 28 mL·kg(-1).

RESULTS AND CONCLUSION

Mean (SD) cardiac and stroke volume indices were greater in the HES group [2.8 L·min(-1)·m(-2) (0.7), 34.1 (6.7) ml·m( -2)] than in the gelatine group [2.2 L·min(-1)·m( -2) (0.6), 25.8 (7.2) ml·m(-2)] after completion of 7 mL·kg(-1) of study solution. At this stage, the effect of gelatine did not differ from Ringer's acetate. After completion of 14 mL·kg(-1) and 21 mL·kg(-1) of colloids, similar cardiac and stroke volume indices were observed and the haemodynamic response was better in both colloid groups than in the Ringer's acetate group. No differences between groups were detected on the first postoperative morning. In the early postoperative phase after cardiac surgery, the effect of a single dose of HES solution on the haemodynamics was superior to the effect of gelatine or Ringer's acetate. However, after repeated administration of the study solutions, the haemodynamics in the two colloid groups appeared to be similar, but superior to the Ringer's acetate group.

Colloids versus crystalloids for fluid resuscitation in critically ill patients

BACKGROUND

Colloid solutions are widely used in fluid resuscitation of critically ill patients. There are several choices of colloid and there is ongoing debate about the relative effectiveness of colloids compared to crystalloid fluids.

OBJECTIVES

To assess the effects of colloids compared to crystalloids for fluid resuscitation in critically ill patients.

SEARCH STRATEGY

We searched the Cochrane Injuries Group's specialised register, CENTRAL, MEDLINE, EMBASE, the National Research Register, Web of Science and MetaRegister. Bibliographies of trials and review articles retrieved were searched. The searches were last updated in December 2006.

SELECTION CRITERIA

Randomised controlled trials (RCTs) of colloids compared to crystalloids, in patients requiring volume replacement. Cross-over trials and trials in pregnant women and neonates were excluded.

DATA COLLECTION AND ANALYSIS

Two authors independently extracted data and rated quality of allocation concealment. Trials with a 'double-intervention', such as those comparing colloid in hypertonic crystalloid to isotonic crystalloid, were analysed separately. The analysis was stratified according to colloid type and quality of allocation concealment.

MAIN RESULTS

We identified 63 eligible trials, 55 of these presented mortality data. COLLOIDS COMPARED TO CRYSTALLOIDS: Albumin or plasma protein fraction - 23 trials reported data on mortality, including a total of 7,754 patients. The pooled relative risk (RR) from these trials was 1.01 (95% confidence interval [95% CI] 0.92 to 1.10). When the trial with poor quality allocation concealment was excluded, pooled RR was 1.00 (95% CI 0.91 to 1.09). Hydroxyethyl starch - 16 trials compared hydroxyethyl starch with crystalloids, n = 637 patients. The pooled RR was 1.05 (95% CI 0.63 to 1.75). Modified gelatin - 11 trials compared modified gelatin with crystalloid, n = 506 patients. The pooled RR was 0.91 (95% CI 0.49 to 1.72). Dextran - nine trials compared dextran with a crystalloid, n = 834 patients. The pooled RR was 1.24 (95% CI 0.94 to 1.65). COLLOIDS IN HYPERTONIC CRYSTALLOID COMPARED TO ISOTONIC CRYSTALLOID: Eight trials compared dextran in hypertonic crystalloid with isotonic crystalloid, including 1,283 randomised participants. Pooled RR was 0.88 (95% CI 0.74 to 1.05).

AUTHORS' CONCLUSIONS

There is no evidence from RCTs that resuscitation with colloids reduces the risk of death, compared to resuscitation with crystalloids, in patients with trauma, burns or following surgery. As colloids are not associated with an improvement in survival, and as they are more expensive than crystalloids, it is hard to see how their continued use in these patients can be justified outside the context of RCTs.