Reporting bias in trials of volume resuscitation with hydroxyethyl starch

Conservative fluid resuscitation protocol does not reduce the incidence of reoperation for bleeding after emergency CABG

Reoperation for bleeding (ROB) after emergency coronary artery bypass grafting (eCABG) has been identified as an independent risk factor for mortality. Consecutively, the influence of fluid intake, fluid output, fluid balance, blood loss, and inotropic demand on ROB were analyzed. This retrospective single-center study included 265 patients undergoing eCABG between 2011 and 2020. From 2018, postoperative hemodynamic management was performed with lower volume administration and higher vasoactive support. The primary outcome measure was the incidence of ROB within 48 h according to altered fluid resuscitation strategy. Consecutively, the influence of fluid intake, fluid output, fluid balance, blood loss, and inotropic demand on ROB were analyzed. Incidence of ROB was independent from the volume resuscitation protocol (P = .3). The ROB group had a higher perioperative risk, which was observed in EuroSCORE II. Fluid intake (P = .021), fluid balance (P = .001), and norepinephrine administration (P = .004) were associated with ROB. Fluid output and blood loss were not associated with ROB (P = .22). Post-test probability was low among all variables. Although fluid management might have an impact on specific postoperative complications, different fluid resuscitation protocols did not alter the incidence of ROB after emergency CABG.

TRIAL REGISTRATION

www.

CLINICALTRIALS

gov registration number NCT04533698; date of registration: August 31, 2020 (retrospectively registered due to nature of the study); URL: https://classic.

CLINICALTRIALS

gov/ct2/show/NCT04533698.

Safety and efficacy of peri-operative administration of hydroxyethyl starch in children undergoing surgery: A systematic review and meta-analysis

BACKGROUND

Hydroxyethyl starch (HES) solutions have shown their efficiency for intravascular volume expansion. A safety recommendation limiting their use in adult patients has recently been made.

OBJECTIVE

To assess the efficacy and adverse effects of HES when administered intra-operatively to paediatric patients.

DESIGN

Systematic review with meta-analyses. Data were analysed using classical mean differences [and their 95% confidence intervals (CIs)] and trial sequential analysis. A Grading of Recommendations Assessment, Development and Evaluation (GRADE) classification was performed for all outcomes. Reviewers extracted valid data, including perioperative total fluid intakes, mortality, renal function, coagulation tests, blood loss and length of hospital and ICU stay.

DATA SOURCES

Searches were performed in databases (Pubmed, Embase, Cochrane central register of controlled trials), clinical trials register, and open access journals not indexed in major databases.

ELIGIBILITY CRITERIA

Randomised controlled trials (RCTs) published before December 2016 involving paediatric patients who received 6% low molecular weight HES.

RESULTS

Nine RCTs involving 530 peri-operative paediatric patients were analysed. Compared with other fluids, HES did not significantly modify the amount of peri-operative fluid administered [mean difference 0.04; 95% CI (-1.76 to 1.84) ml kg], urine output [mean difference -33; 95% CI (-104 to 38) ml kg] or blood loss [mean difference -0.09; (-0.32 to 0.15) ml kg]. Trial sequential analysis determined that the outcomes for peri-operative fluid and urine output were underpowered. All results were graded as very low quality of evidence.

CONCLUSION

Intravascular volume expansion with low molecular weight 6% HES did not appear to modify renal function, blood loss or transfusion when administered to children during the peri-operative period. However, given the lack of statistical power and the very low GRADE quality of evidence, more high-quality RCTs are needed to explore these outcomes.

Understanding the Harms of HES: A Review of the Evidence to Date

Intravenous (IV) fluid resuscitation is one of the most common interventions in intensive care medicine. Despite clear guidelines, the choice of IV fluid is largely dependent on physician preference instead of high-quality evidence of efficacy and safety. This is particularly the case for synthetic colloids, such as hydroxyethyl starch (HES). The use of HES in critical care has been associated with increased rates of acute kidney injury (AKI), renal replacement therapy and mortality. In light of this, current guidelines and scientific and regulatory bodies do not recommend the use of HES for fluid therapy in critical illness and caution against its use in many other settings. Despite this, HES products are still debated and used. Awareness of the indications, contraindications, doses, benefits and adverse effects for IV fluids, as well as recommendations from scientific and regulatory bodies, is essential to guarantee patients' safety. Poor awareness of optimal IV fluid therapy has recently been revealed in some countries including Turkey. Therefore, we provide a review of fluids used for resuscitation, discuss safety data and adverse effects of HES, such as increased AKI and mortality, and discuss recent updates from scientific and regulatory bodies in order to raise awareness of fluid therapy. We conclude that given the lack of a clear benefit of HES in any clinical setting and the availability of safer alternatives, such as crystalloids and albumin, HES should be avoided.

Hydroxyethyl starch and kidney function: A retrospective study in patients undergoing therapeutic plasma exchange

PURPOSE

Hydroxyethyl starch (HES) and albumin are used as replacement fluids during therapeutic plasma exchange (TPE). HES solutions are no longer recommended in critically ill patients due to its effect on kidneys and coagulation. In this retrospective study, we tried to look at the association between cumulative HES administration and kidney function in patients undergoing TPE.

METHODS

Transfusion medicine department register was scrutinized to identify adult patients who had completed at least 5 cycles of TPE during the period June 2014-May 2015. Patient demographics, indication for TPE, amount of plasma removed, amount of colloid administered, adverse events and vascular access details were collected. Electronic hospital database was scrutinized to retrieve lab parameters, including blood urea and serum creatinine (before and after 5 cycles of TPE) and platelet count. Baseline renal parameters were compared with post TPE values using Wilcoxon signed rank test. A p value <0.05 was kept as significant.

RESULTS

Of the 593 patients who received TPE during the study period, 104 patients fulfilled the inclusion criteria. Forty-five patients out of 104 received TPE in the intensive care unit. All patients received 2500 ml of HES during the study period. Blood urea and serum creatinine values, when compared to baseline, significantly decreased after 5 cycles of TPE (p = 0.004, p = 0.001, respectively).

CONCLUSION

Blood urea and serum creatinine, used as markers of renal function, improved in patients requiring multiple doses of HES solutions during TPE. Further studies using novel renal biomarkers are required to examine whether HES induces any structural damage to kidneys.

Comparison of hydroxyethyl starch regulatory summaries from the Food and Drug Administration and the European Medicines Agency

This article aims to highlight the positions of the Food and Drug Administration and the European Medicines Agency regarding use and marketing of hydroxyethyl starch (HES) products, and how these have changed over recent years. In 2013, warnings from both agencies advised against use of HES in critically ill patients, including patients with sepsis, when several large randomized controlled trials on volume resuscitation in critical illness failed to observe clinically beneficial effects of HES. In areas such as patient monitoring and requirements for further clinical trials, the FDA and EMA are very much in agreement in their recommendations. However, EMA guidance is generally more restrictive on HES usage compared to that from the FDA. Differences in data presented to regulatory authorities, bias in study results and inherent weakness of meta-analyses used for drug surveillance purposes, plus different risk-management approaches used by the two regulatory authorities, likely contribute to different outcomes in their regulations concerning use of HES.

Resuscitation with polymeric plasma substitutes is permissive for systemic inflammatory response syndrome and sepsis in multiply injured patients: a retrospective cohort study

Objective

Multiple trauma is often accompanied by systemic inflammatory response syndrome (SIRS). The aim of this study was to investigate the impact of polymeric plasma substitutes on the development of SIRS or sepsis.

Methods

We included 2969 patients aged ≥16 years with an Injury Severity Score (ISS) >16 in this study. The sample was subdivided into three groups: patients who did not receive colloids and those who received <5L colloids and >5L colloids within the first 48 h. Data were analyzed using IBM SPSS^® for Windows version 22.0; analysis of variance was used for continuous normally distributed data and Kruskal–Wallis test for categorical data. The predictive quality of colloid treatment was analyzed using the receiver operating characteristic (ROC) curves. Independent predictively was analyzed by binary logistic regression. Data were considered significant if P < 0.05. Data are presented as the mean ± standard deviation.

Results

The SIRS score increased with the amount of colloid used (1.9 ± 1.4 vs. 2.4 ± 1.2 vs. 3.2 ± 0.9; P < 0.001). However, the predictive quality was low, with an area under the ROC of 0.693 for SIRS and 0.669 for sepsis (P < 0.001). Binary logistic regression revealed colloids as an independent factor for the development of SIRS and sepsis (odds ratios: SIRS 3.325 and sepsis 8.984; P < 0.001).

Conclusion

Besides other factors, colloids have a significant permissive effect and are independent predictors for the development of SIRS and sepsis in multiply injured patients.

Trial registration ‘Retrospektive Analysen in der Chirurgischen Intensivmedizin’ No. St. V. 01-2008

Beautiful small: Misleading large randomized controlled trials? The example of colloids for volume resuscitation

In anesthesia and intensive care, treatment benefits that were claimed on the basis of small or modest-sized trials have repeatedly failed to be confirmed in large randomized controlled trials. A well-designed small trial in a homogeneous patient population with high event rates could yield conclusive results; however, patient populations in anesthesia and intensive care are typically heterogeneous because of comorbidities. The size of the anticipated effects of therapeutic interventions is generally low in relation to relevant endpoints. For regulatory purposes, trials are required to demonstrate efficacy in clinically important endpoints, and therefore must be large because clinically important study endpoints such as death, sepsis, or pneumonia are dichotomous and infrequently occur. The rarer endpoint events occur in the study population; that is, the lower the signal-to-noise ratio, the larger the trials must be to prevent random events from being overemphasized. In addition to trial design, sample size determination on the basis of event rates, clinically meaningful risk ratio reductions and actual patient numbers studied are among the most important characteristics when interpreting study results. Trial size is a critical determinant of generalizability of study results to larger or general patient populations. Typical characteristics of small single-center studies responsible for their known fragility include low variability of outcome measures for surrogate parameters and selective publication and reporting. For anesthesiology and intensive care medicine, findings in volume resuscitation research on intravenous infusion of colloids exemplify this, since both the safety of albumin infusion and the adverse effects of the artificial colloid hydroxyethyl starch have been confirmed only in large-sized trials.