Safety of Modern Starches Used During Surgery

Morbidity and Mortality of Crystalloids Compared to Colloids in Critically Ill Surgical Patients

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Background

The multicenter randomized Colloids versus Crystalloids for the Resuscitation of the Critically Ill (CRISTAL) trial was designed to test whether colloids altered mortality compared to crystalloids in the resuscitation of intensive care unit patients with hypovolemic shock. This preplanned analysis tested the same hypothesis in the subgroup of surgical patients.

Methods

The CRISTAL trial prospectively defined patients as critically ill surgical patients whenever they underwent emergency or scheduled surgery immediately before or within 24 h of intensive care unit admission and had hypovolemic shock. The primary outcome measure was death by day 28. Secondary outcome measures included death by day 90, the need for renal replacement therapy, or the need for fresh frozen plasma transfusion.

Results

There were 741 critically ill surgical patients, 356 and 385 in the crystalloid and colloid arm, respectively. Median (interquartile range) age was 66 (52 to 76) yr, and 484 (65.3%) patients were male. Surgery was unscheduled in 543 (73.3%) cases. Mortality by day 28 did not significantly differ for crystalloids 84 (23.6%) versus colloids 100 (26%; adjusted odds ratio, 0.86; 95% CI, 0.61 to 1.21; P = 0.768). Death by day 90 (111 [31.2%] vs. 122 [31.7%]; adjusted odds ratio, 0.97; 95% CI, 0.70 to 1.33; P = 0.919) did not significantly differ between groups. Renal replacement therapy was required for 42 (11.8%) patients in the crystalloids arm versus 49 (12.7%) in the colloids arm (P = 0.871).

Conclusions

The authors found no survival benefit when comparing crystalloids to colloids in critically ill surgical patients.

No Differences in Renal Function between Balanced 6% Hydroxyethyl Starch (130/0.4) and 5% Albumin for Volume Replacement Therapy in Patients Undergoing Cystectomy: A Randomized Controlled Trial

BACKGROUND

The use of artificial colloids has declined in critical care, whereas they are still used in perioperative medicine. Little is known about the nephrotoxic potential in noncritically ill patients during routine surgery. The objective of this trial was to evaluate the influences of albumin 5% and balanced hydroxyethyl starch 6% (130/0.4) on renal function and kidney injury.

METHODS

One hundred urologic patients undergoing elective cystectomy were randomly assigned for this prospective, single-blinded, controlled study with two parallel groups to receive either albumin 5% or balanced hydroxyethyl starch 6% (130/0.4) as the only perioperative colloid. The primary endpoint was the ratio of serum cystatin C between the last visit at day 90 and the first preoperative visit. Secondary endpoints were estimated glomerular filtration rate and serum neutrophil gelatinase-associated lipocalin until the third postoperative day and risk, injury, failure, loss, and end-stage renal disease criteria at postoperative days 3 and 90.

RESULTS

The median cystatin C ratio was 1.11 (interquartile range, 1.01 to 1.23) in the albumin and 1.08 (interquartile range, 1.00 to 1.20) in the hydroxyethyl starch group (median difference = 0.03; 95% CI, -0.09 to 0.08; P = 0.165). Also, there were no significant differences concerning serum cystatin C concentrations; estimated glomerular filtration rate; risk, injury, failure, loss, and end-stage renal disease criteria; and neutrophil gelatinase-associated lipocalin. Infusion requirements, transfusion rates, and perioperative hemodynamics were similar in both groups.

CONCLUSIONS

With respect to renal function and kidney injury, this study indicates that albumin 5% and balanced hydroxyethyl starch 6% have comparable safety profiles in noncritically ill patients undergoing major surgery.

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

Controversies in the use of hydroxyethyl starch solutions in small animal emergency and critical care

OBJECTIVES

To (1) review the development and medical applications of hydroxyethyl starch (HES) solutions with particular emphasis on its physiochemical properties; (2) critically appraise the available evidence in human and veterinary medicine, and (3) evaluate the potential risks and benefits associated with their use in critically ill small animals.

DATA SOURCES

Human and veterinary original research articles, scientific reviews, and textbook sources from 1950 to the present.

HUMAN DATA SYNTHESIS

HES solutions have been used extensively in people for over 30 years and ever since its introduction there has been a great deal of debate over its safety and efficacy. Recently, results of seminal trials and meta-analyses showing increased risks related to kidney dysfunction and mortality in septic and critically ill patients, have led to the restriction of HES use in these patient populations by European regulatory authorities. Although the initial ban on the use of HES in Europe has been eased, proof regarding the benefits and safety profile of HES in trauma and surgical patient populations has been requested by these same European regulatory authorities.

VETERINARY DATA SYNTHESIS

The veterinary literature is limited mostly to experimental studies and clinical investigations with small populations of patients with short-term end points and there is insufficient evidence to generate recommendations.

CONCLUSIONS

Currently, there are no consensus recommendations regarding the use of HES in veterinary medicine. Veterinarians and institutions affected by the HES restrictions have had to critically reassess the risks and benefits related to HES usage based on the available information and sometimes adapt their procedures and policies based on their reassessment. Meanwhile, large, prospective, randomized veterinary studies evaluating HES use are needed to achieve relevant levels of evidence to enable formulation of specific veterinary guidelines.

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.

Fluid replacement with hydroxyethyl starch in critical care--a reassessment

BACKGROUND

Hydroxyethyl starch (HES) is used for fluid replacement in millions of patients around the world every year, yet it has been found to have adverse effects that have a negative impact on patient survival. Recent clinical trials with a modern HES solution (HES 130) and meta-analyses now enable a reassessment of its risks and benefits.

METHODS

On the basis of a selective literature search focusing on reports of the use of HES 130/0.4 and HES 130/0.42 in sepsis, trauma, and intensive care medicine, data from randomized controlled trials (RCTs) are presented, and up-to-date meta-analyses and reviews are discussed. Moreover, the authors conducted an independent meta-analysis of HES 130 in comparison to crystalloids or albumin in intensive care medicine, sepsis, and trauma.

RESULTS

Seven RCTs were evaluated, involving a total of 7838 patients treated for sepsis or trauma, or in intensive care. HES 130 was associated with a higher cumulative risk of death (relative risk [RR] 1.10, 95% confidence interval [CI] 1.01-1.20), more frequent need for a renal replacement procedure (RR 1.26, 95% CI 1.08-1.46), and more frequent need for blood transfusion (RR 1.22, 95% CI 1.08-1.37). There was no patient-relevant benefit. Four recent meta-analyses of data from a total of more than 10 000 patients confirmed these concerns about the safety of HES in general and, in particular, of low-molecular-weight HES 130 for patients in intensive care. The safety of 6% HES 130 in the immediate perioperative period has not been adequately demonstrated.

DISCUSSION

Because of safety concerns, fluid replacement with HES in critically ill patients cannot be recommended. Evidence for its superior efficacy, safety and cost effectiveness in preoperative use is also lacking.