Hydroxyethyl starch (HES) versus other fluid therapies: effects on kidney function

Comparison of the Effects of Ringer's Lactate and 6% Hydroxyethyl Starch 130/0.4 on Blood Loss and Need for Blood Transfusion After Off-Pump Coronary Artery Bypass Graft Cardiac Surgery

Background Infusion of crystalloids fluid replacement therapy tends to cause a greater expansion of intravascular volume. However, colloids can affect blood coagulation leading to greater blood loss and transfusion requirements. This study compared the intraoperative and postoperative blood loss with Ringer's lactate (RL) versus 6% hydroxyethyl starch (HES) 130/0.4 as infusion fluid during cardiac surgery. Methods Eighty adult male and female patients undergoing elective cardiac surgery were randomly assigned to receive either RL or 6% HES 130/0.4 20 ml/kg during off-pump coronary artery bypass graft (OP-CABG) surgery. Intraoperative blood loss and 24 hours postoperative chest tube drainage were the primary outcomes. Simultaneously, blood transfusions, thromboelastometry variables, total fluid requirement, renal function, and intensive care unit (ICU) stay were assessed. Results The intraoperative blood loss was similar (p > 0.05) with HES (716 ml) and RL (658 ml). Postoperative chest tube drainage was higher (p < 0.05) with HES (513 ml) as against RL (449 ml). The total fluid requirement was higher in the RL group. Alteration of thromboelastometry variables, renal function, and ICU stay was comparable between the two groups. Postoperative chest tube drainage was less with the use of RL during cardiac surgery. A lesser total fluid requirement in the HES group did not lead to any improvement in renal function and the length of ICU stay. Conclusions Crystalloids (RL) provide similar outcomes to HES and can be used as substitutes to colloids during cardiac surgery. However, further large-scale multicenter studies with varied indications can be suggested to substantiate the equivalence of crystalloids to colloids in perioperative management.

Nanomedicines - Tiny particles and big challenges

After decades of research, nanotechnology has been used in a broad array of biomedical products including medical devices, drug products, drug substances, and pharmaceutical-grade excipients. But like many great achievements in science, there is a fine balance between the risks and opportunities of this new technology. Some materials and surface structures in the nanosize range can exert unexpected toxicities and merit a more detailed safety assessment. Regulatory agencies such as the United States Food and Drug Administration or the European Medicines Agency have started dealing with the potential risks posed by nanomaterials. Considering that a thorough characterization is one of the key aspects of controlling such risks this review presents the regulatory background of nanosafety assessment and provides some practical advice on how to characterize nanomaterials and drug formulations. Further, the challenges of how to maintain and monitor pharmaceutical quality through a highly complex production processes will be discussed.

Labelling and Clinical Performance of Human Leukocytes Labelled with 99mTc-HMPAO Using Leukokit® with Gelofusine versus Leukokit® with HES as Sedimentation Agent

The scintigraphy with radiolabelled autologous leukocytes (WBCs) is considered the gold-standard technique for imaging infections. Leukokit® is a commercially available, disposable, sterile kit for labelling WBCs ex vivo. In this kit, WBCs isolation from red blood cells (RBCs) was performed using poly(O-2-hydroxyethyl)starch (HES) as the RBCs sedimentation agent. Due to its poor availability, HES has been recently replaced by Gelofusine as the RBC sedimentation agent. The aim of this study was to compare the labelling efficiency and the diagnostic accuracy of WBCs labelled with Leukokit® with HES vs Leukokit® with Gelofusine. WBCs were isolated using HES or Gelofusine for 45 minutes and then purified from platelets (PLTs) and labelled with 1.1 ± 0.3 GBq of freshly prepared 99mTc-HMPAO. The following parameters were evaluated: the number and type of recovered WBCs, RBCs contamination, PLTs contamination, vitality of neutrophils, and chemotactic properties of neutrophils. Clinical comparison was performed between 80 patients (33 males; age 67.5 ± 14.2) injected with 99mTc-HMPAO-WBCs, using HES as the sedimentation agent, and 92 patients (38 males; age 68.2 ± 12.8) injected with 99mTc-HMPAO-WBCs using Gelofusine as the sedimentation agent. Patients were affected by prosthetic joint infections, peripheral bone osteomyelitis, or vascular graft infection. We compared radiolabelling efficiency (LE), final recovery yield (RY), and diagnostic outcome based on microbiology or 2-year follow-up. Results showed that HES provides the lowest RBCs and PLTs contamination, but Gelofusine provides the highest WBC recovery. Both agents did not influence the chemotactic properties of WBCs, and no differences were found in terms of LE and RY. Sensitivity, specificity, and accuracy were also not significantly different for WBCs labelled with both agents (diagnostic accuracy 90.9%, CI = 74.9-96.1 vs 98.3%, CI = 90.8-100, for HES and Gelofusine, respectively). In conclusion, Gelofusine can be considered a suitable alternative of HES for WBCs separation and labelling.

Perioperative fluid management in major hepatic resection: an integrative review

BACKGROUND

Fluid intervention and vasoactive pharmacological support during hepatic resection depend on the preference of the attending clinician, institutional resources, and practice culture. Evidence-based recommendations to guide perioperative fluid management are currently limited. Therefore, we provide a contemporary clinical integrative overview of the fundamental principles underpinning fluid intervention and hemodynamic optimization for adult patients undergoing major hepatic resection.

DATA SOURCES

A literature review was performed of MEDLINE, EMBASE and the Cochrane Central Registry of Controlled Trials using the terms "surgery", "anesthesia", "starch", "hydroxyethyl starch derivatives", "albumin", "gelatin", "liver resection", "hepatic resection", "fluids", "fluid therapy", "crystalloid", "colloid", "saline", "plasma-Lyte", "plasmalyte", "hartmann's", "acetate", and "lactate". Search results for MEDLINE and EMBASE were additionally limited to studies on human populations that included adult age groups and publications in English.

RESULTS

A total of 113 articles were included after appropriate inclusion criteria screening. Perioperative fluid management as it relates to various anesthetic and surgical techniques is discussed.

CONCLUSIONS

Clinicians should have a fundamental understanding of the surgical phases of the resection, hemodynamic goals, and anesthesia challenges in attempts to individualize therapy to the patient's underlying pathophysiological condition. Therefore, an ideal approach for perioperative fluid therapy is always individualized. Planning and designing large-scale clinical trials are imperative to define the optimal type and amount of fluid for patients undergoing major hepatic resection. Further clinical trials evaluating different intraoperative goal-directed strategies are also eagerly awaited.

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.

[State of the art in fluid and volume therapy : A user-friendly staged concept]

Adequate fluid therapy is highly important for the perioperative outcome of our patients. Both, hypovolemia and hypervolemia can lead to an increase in perioperative complications and can impair the outcome. Therefore, perioperative infusion therapy should be target-oriented. The main target is to maintain the patient's preoperative normovolemia by using a sophisticated, rational infusion strategy.Perioperative fluid losses should be discriminated from volume losses (surgical blood loss or interstitial volume losses containing protein). Fluid losses as urine or perspiratio insensibilis (0.5-1.0 ml/kg/h) should be replaced by balanced crystalloids in a ratio of 1:1. Volume therapy step 1: Blood loss up to a maximum value of 20% of the patient's blood volume should be replaced by balanced crystalloids in a ratio of 4(-5):1. Volume therapy step 2: Higher blood losses should be treated by using iso-oncotic, preferential balanced colloids in a ratio of 1:1. For this purpose hydroxyethyl starch can also be used perioperatively if there is no respective contraindication, such as sepsis, burn injuries, critically ill patients, renal impairment or renal replacement therapy, and severe coagulopathy. Volume therapy step 3: If there is an indication for red cell concentrates or coagulation factors, a differentiated application of blood and blood products should be performed.

Prediction and Prevention of Acute Kidney Injury after Cardiac Surgery

The incidence of acute kidney injury after cardiac surgery (CS-AKI) ranges from 33% to 94% and is associated with a high incidence of morbidity and mortality. The etiology is suggested to be multifactorial and related to almost all aspects of perioperative management. Numerous studies have reported the risk factors and risk scores and novel biomarkers of AKI have been investigated to facilitate the subclinical diagnosis of AKI. Based on the known independent risk factors, many preventive interventions to reduce the risk of CS-AKI have been tested. However, any single preventive intervention did not show a definite and persistent benefit to reduce the incidence of CS-AKI. Goal-directed therapy has been considered to be a preventive strategy with a substantial level of efficacy. Many pharmacologic agents were tested for any benefit to treat or prevent CS-AKI but the results were conflicting and evidences are still lacking. The present review will summarize the current updated evidences about the risk factors and preventive strategies for CS-AKI.

Effect of synthetic colloid administration on coagulation in healthy dogs and dogs with systemic inflammation

Background

Synthetic colloids are often used during fluid resuscitation and affect coagulation.

Objective

To compare the effects of an isotonic crystalloid and synthetic colloid on coagulation in healthy dogs and dogs with systemic inflammation.

Animals

Sixteen adult purpose‐bred Beagles.

Methods

Randomized, placebo‐controlled, blinded study. Dogs were randomized into one of two groups receiving fluid resuscitation with either 40 mL/kg IV 0.9% NaCl or tetrastarch after administration of lipopolysaccharide or an equal volume of placebo. After a 14‐day washout period, the study was repeated such that dogs received the opposite treatment (LPS or placebo) but the same resuscitation fluid. Blood samples were collected at 0, 1, 2, 4, and 24 hours for measurement of coagulation variables.

Results

Administration of either fluid to healthy dogs and dogs with systemic inflammation resulted in similar increases in prothrombin time and activated clotting time. In comparison to saline administration, tetrastarch administration resulted in significantly decreased R (P = .017) in healthy dogs, as well as significantly increased activated partial thromboplastin time (P ≤ .016), CL30% (P ≤ .016), and K (P < .001) and significantly decreased platelet count (P = .019), α (P ≤ .001), MA (P < .001), and von Willebrand factor antigen (P < .001) and collagen binding activity (P ≤ .003) in both healthy dogs and dogs with systemic inflammation.

Conclusions and Clinical Importance

Tetrastarch bolus administration to dogs with systemic inflammation resulted in a transient hypocoagulability characterized by a prolonged activated partial thromboplastin time, decreased clot formation speed and clot strength, and acquired type 1 von Willebrand disease.

Fluid therapy in critical illness

Major surgery and critical illnesses such as sepsis and trauma all disturb normal physiological fluid handling. Intravenous fluid therapy for resuscitation and fluid maintenance is a central part of medical care during these conditions, yet the evidence base supporting practice in this area lacks answers to a number of important questions. Recent research developments include a refinement of our knowledge of the endothelial barrier structure and function and a focus on the potential harm that may be associated with intravenous fluid therapy. Here, we briefly describe the contemporary view of fluid physiology and how this may be disrupted by pathological processes. The important themes in critical illness fluid research are discussed, with a particular focus on two emerging ideas: firstly, that individualising fluid treatment to the patient, their underlying disease state and the phase of that illness may be key to improving clinical outcomes using fluid interventions and, secondly, that fluids should be considered to be drugs, with specific indications and contraindications, dose ranges and potential toxicities.

[Limited applications for hydroxyethyl starch : background and alternative concepts]

BACKGROUND

Within the framework of a risk assessment procedure the Committee for Risk Assessment of Pharmacovigilance (PRAC) of the European Medicines Agency (EMA) came to the conclusion that the benefits of hydroxylethyl starch infusion solutions (HES) no longer outweighed the risks and on 14 June 2013 recommended that approval should be suspended. Until the procedure has finally been concluded, which could last several months, the Federal Institute for Drugs and Medical Products (BfArM) has recommended that HES should not be used.

AIM

The aim of this article is to present the data situation in the most objective and compact way and to ultimately give the reader the foundations in order to be able to form a personal opinion. In addition an attempt will be made to describe a concept how infusion therapy can be carried out without using hydroxyethyl starch (HES).

MATERIAL AND METHODS

The background to this decision is given based on a review of the literature and the relevance for intensive care, emergency and perioperative medicine is assessed. Furthermore, a concept of infusion therapy without hydroxyethyl starch is formulated also based on the results of current studies.

RESULTS

For infusion regimens without HES it should be noted that gelatin represents a considerable risk for anaphylactic reactions, that transfer of the new variants of Creutzfeldt-Jacob disease (bovine spongiform encephalopathy BSE) cannot fundamentally be excluded and that some evidence has been found that gelatin can cause kidney injury, probably in a similar way to HES. With respect to the cost-benefit analysis of infusion solutions, blood loss in adults of approximately 1-1.5 l can be substituted by balanced crystalloids (basic therapy 4-5 times compared to the amount of blood lost). For larger blood losses small amounts of hyperoncotic albumin solution (20 %) or alternatively 5 % albumin solution can be used. The 20 % albumin solution seems to have some advantages because it has a higher volume effect (approximately 200 %) and can be more favourable for the fluid balance than 5 % albumin solution. Blood losses greater than 2-3 l normally also require administration of blood products (e.g. fresh frozen plasma FFP and erythrocyte concentrates EC).

CONCLUSIONS

The third generation HES solutions cannot be completely replaced by other colloids and in future crystalloids will more strongly again broadly form the basis for infusion therapy. In this aspect balanced crystalloids have priority with respect to the acid-base equilibrium. The history of HES has impressively shown that infusion therapy must be adjusted on a scientifically founded basis, whether in intensive care medicine, perioperative or emergency medicine. Large prospective studies with clinically relevant endpoints are urgently needed.

Choice of Fluids in Severe Septic Patients - A Cost-effectiveness Analysis Informed by Recent Clinical Trials

Fluid resuscitation with colloids is an established second line therapy for septic patients. Evidence of relative efficacy outcomes is tempered by considerations of the relative costs of the individual fluids. An assessment of recent large clinical trials was performed, resulting in a ranking in the efficacy of these therapies. Probabilities for mortality and the need for renal replacement therapy (RRT) were derived and used to inform a decision analysis model comparing the effect of crystalloid, albumin and hydroxyethyl starch solutions in severe septic patients followed from hospital admission to 90 days in intensive care. The US payer perspective was used. Model inputs for costs and efficacy were derived from the peer-reviewed literature, assuming that that all fluid preparations are bio-equivalent within each class of these therapies. Probabilities for mortality and the need for renal replacement therapy (RRT) data were synthesized using a Bayesian meta-analysis. Relative to crystalloid therapy, 0.21 life years were gained with albumin and 0.85 life years were lost with hydroxyethyl starch. One-way sensitivity analysis showed that the model's outcomes were sensitive to the cost of RRT but not to the costs of the actual fluids or any other costs. We conclude that albumin may be the most cost-effective treatment in these patients when the total medical costs and iatrogenic morbidities involved in treating sepsis with fluids are considered. These results should assist and inform decision making in the choice of these drugs.

Clinical controversies in the management of critically ill patients with severe sepsis: resuscitation fluids and glucose control

Severe sepsis with multiple organ dysfunction remains the most common cause of death for patients treated in intensive care units. As there is no specific treatment for severe sepsis, current management consists of antibiotics, source control and the use of supportive therapies to sustain life while waiting for the adverse effects of sepsis-induced organ dysfunction to subside. Despite the central role of supportive therapies, few have been subjected to rigorous evaluation; two exceptions are the choice of resuscitation fluid and intensity of glucose control. Current data support the use of a crystalloid fluid with the addition of albumin when needed for fluid resuscitation. Administration of hydroxyethyl starch is harmful and should be avoided. Stress hyperglycemia should be treated when blood glucose concentration exceeds 180 mg/dL (10.0 mmol/L) and when insulin therapy is needed it should be targeted to a blood glucose concentration of 144-180 mg/dL (8-10 mmol/L).

Impact of intravascular volume replacement and transfusion on outcome: where are we now?

Intravenous fluid administration is often required to counteract haemodynamic instability during emergency and elective surgeries, as well as in the intensive care unit. However, the best type and the amount of fluid required are controversial. A recent meta-analysis suggested that there is no difference among different types of colloids on outcome. Furthermore, colloids and crystalloids seem to be comparable in terms of efficiency in reverting haemodynamic instability, as well as morbidity and mortality. The interpretation of the results of different randomised controlled trials is somewhat difficult - the context must be always kept in mind. For example, results may differ in septic as compared to non-septic patient populations. Another important aspect concerns the effects on the macro- versus microcirculation. More recent studies emphasise that the microcirculation has to be taken into account when studying and interpreting the interaction between fluid therapy and the underlying disease. Nevertheless, the macrocirculation and clinical parameters have to be considered as well. Given that red blood cells remain the most important oxygen carriers, recent evidence regarding blood age may stimulate new studies according to the actual range for blood storage. Artificial oxygen carriers may play a role in specific situations, where the transfusion is indicated but the access to blood is problematic, but there is doubt that they may replace blood transfusion.

Relative survival benefit and morbidity with fluids in severe sepsis - a network meta-analysis of alternative therapies

BACKGROUND

Fluid resuscitation is widely practiced in intensive care units for the treatment of sepsis. A comparison of the evidence base of different fluids may inform therapeutic choice.

METHODS

The risks of mortality and morbidity (the need for renal replacement therapies (RRT)) were assessed in patients with severe sepsis. A network meta-analysis compared trials for crystalloids, albumin and hydroxyethyl starch (HES). A literature search of human randomized clinical trials was conducted in databases, the bibliographies of other recent relevant systematic reviews and data reported at recent conferences. Mortality outcomes and RRT data with the longest follow up period were compared. A Bayesian network meta-analysis assessed the risk of mortality and a pair-wise metaanalysis assessed RRT using crystalloids as the reference treatment.

RESULTS

13 studies were identified. A fixed-effects meta-analysis of mortality data in the trials demonstrated an odds-ratio (OR) of 0.90 between crystalloids and albumin, 1.25 between crystalloids and HES and 1.40 between albumin and HES. The probability that albumin is associated with the highest survival was 96.4% followed by crystalloid at 3.6%, with a negligible probability for HES. Sub-group analyses demonstrated the robustness of this result to variations in fluid composition, study source and origin of septic shock. A random-effects pairwise comparison for the risk of RRT provided an OR of 1.52 favoring crystalloid over HES.

CONCLUSION

Fluid therapy with albumin was associated with the highest survival benefit. The higher morbidity with HES may affect mortality and requires consideration by prescribers.

Hydroxyethyl starch (HES) versus other fluid therapies: effects on kidney function

BACKGROUND

Hydroxyethyl starches (HES) are synthetic colloids commonly used for fluid resuscitation to replace intravascular volume, yet they have been increasingly associated with adverse effects on kidney function. This is an update of a Cochrane review first published in 2010.

OBJECTIVES

To examine the effects of HES on kidney function compared to other fluid resuscitation therapies in different patient populations.

SEARCH METHODS

We searched the Cochrane Renal Group's specialised register, the Cochrane Central Register of Controlled Trials (CENTRAL, in The Cochrane Library), MEDLINE, EMBASE, MetaRegister and reference lists of articles. The most recent search was completed on November 19, 2012.

SELECTION CRITERIA

Randomised controlled trials (RCTs) and quasi-RCTs in which HES was compared to an alternate fluid therapy for the prevention or treatment of effective intravascular volume depletion. Primary outcomes were renal replacement therapy (RRT), author-defined kidney failure and acute kidney injury (AKI) as defined by the RIFLE criteria.

DATA COLLECTION AND ANALYSIS

Screening, selection, data extraction and quality assessments for each retrieved article were carried out by two authors using standardised forms. All outcomes were analysed using relative risk (RR) and 95% confidence intervals (95% CI). Authors were contacted when published data were incomplete. Preplanned sensitivity and subgroup analyses were performed after data were analysed with a random-effects model.

MAIN RESULTS

This review included 42 studies (11,399 patients) including 19 studies from the original review (2010), as well as 23 new studies. Fifteen studies were excluded from the original review (nine retracted from publication due to concerns about integrity of data and six lacking individual patient creatinine data for the calculation of RIFLE criteria). Overall, there was a significant increase in the need for RRT in the HES treated individuals compared to individuals treated with other fluid therapies (RR 1.31, 95% CI 1.16 to 1.49; 19 studies, 9857 patients) and the number with author-defined kidney failure (RR 1.59, 95% CI 1.26 to 2.00; 15 studies, 1361 patients). The RR of AKI based on RIFLE-F (failure) criteria also showed an increased risk of AKI in individuals treated with HES products (RR 1.14, 95% CI 1.01 to 1.30; 15 studies, 8402 participants). The risk of meeting urine output and creatinine based RIFLE-R (risk) criteria for AKI was in contrast in favour of HES therapies (RR 0.95, 95% CI 0.91 to 0.99; 20 studies, 8769 patients). However, when RIFLE-R urine output based outcomes were excluded as per study protocol, the direction of AKI risk again favoured the other fluid type, with a non-significant RR of AKI in HES treated patients (RR 1.05, 95% CI 0.97 to 1.14; 8445 patients). A more robust effect was seen for the RIFLE-I (injury) outcome, with a RR of AKI of 1.22 (95% CI 1.08 to 1.37; 8338 patients). No differences between subgroups for the RRT and RIFLE-F based outcomes were seen between sepsis versus non-sepsis patients, high molecular weight (MW) and degree of substitution (DS) versus low MW and DS (≥ 200 kDa and > 0.4 DS versus 130 kDa and 0.4 DS) HES solutions, or high versus low dose treatments (i.e. ≥ 2 L versus < 2 L). There were differences identified between sepsis versus non-sepsis subgroups for the RIFLE-R and RIFLE-I based outcomes only, which may reflect the differing renal response to fluid resuscitation in pre-renal versus sepsis-associated AKI. Overall, methodological quality of the studies was good.

AUTHORS' CONCLUSIONS

The current evidence suggests that all HES products increase the risk in AKI and RRT in all patient populations and a safe volume of any HES solution has yet to be determined. In most clinical situations it is likely that these risks outweigh any benefits, and alternate volume replacement therapies should be used in place of HES products.

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.

Effects of different resuscitation fluids on pulmonary expression of aquaporin1 and aquaporin5 in a rat model of uncontrolled hemorrhagic shock and infection

BACKGROUND

To investigate the effects of fluids resuscitation on pulmonary expression of aquaporin1 and aquaporin5 in a rat model of uncontrolled hemorrhagic shock and infection.

METHODS

Sixty Sprague-Dawley rats were randomly assigned to five groups, sham operation group (Group C) and four treated groups: no fluid resuscitation group (Group NF), groups resuscitated with Lactated Ringer's (LR),7.5% NaCl (HTS) and Hydroxyl ethyl starch (HES) respectively. Three-phased uncontrolled hemorrhagic shock and infection model was used. Phase I: Massive hemorrhage with a mean arterial pressure of 35-40 mmHg for 60 min, and followed by infection of lipopolysaccharide. Then some animals were resuscitated with solutions mentioned above, until 90 min. Phase II: At hemorrhagic shock 90 minutes, phase II of 60 minutes began with hemostasis and returning of all the initial shed blood. Phase III: Observation phase for 3.5 hours. After phase III, arterial blood gas analysis and the survival rates of the rats were recorded, Wet-to-dry lung weight ratio, BALF protein, pulmonary permeability index, and expressions of aquaporin1 and aquaporin5 were tested.

RESULTS

The expressions of aquaporin1 and aquaporin5 were decreased in treatment groups comparing with sham operation group. Group HES and Group HTS decreased pulmonary vascular permeability and Wet-to-dry lung weight ratio, improved arterial blood gas analysis and survival rates, and attenuated the decreased pulmonary expression of aquaporin1 and aquaporin5 after the "two-hit", comparing with groups NF and LR,but these beneficial effects were blunted in group HTS.

CONCLUSION

The expression of aquaporin1 and aquaporin5 may play important roles in formation of pulmonary edema. Resuscitation with HTS and HES, especially HES can reduce lung injury after hemorrhagic shock, partly by up-regulating the expressions of aquaporin1 and aquaporin5.

Management of urinary tract emergencies in small animals

This article focuses on some of the most commonly seen urinary tract emergencies in dogs and cats, with emphasis on basic pathophysiology, diagnosis, and emergency management of these cases.

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.

Hydroxyethyl starch 130/0.38-0.45 versus crystalloid or albumin in patients with sepsis: systematic review with meta-analysis and trial sequential analysis

OBJECTIVE

To assess the effects of fluid therapy with hydroxyethyl starch 130/0.38-0.45 versus crystalloid or albumin on mortality, kidney injury, bleeding, and serious adverse events in patients with sepsis.

DESIGN

Systematic review with meta-analyses and trial sequential analyses of randomised clinical trials.

DATA SOURCES

Cochrane Library, Medline, Embase, Biosis Previews, Science Citation Index Expanded, CINAHL, Current Controlled Trials, Clinicaltrials.gov, and Centerwatch to September 2012; hand search of reference lists and other systematic reviews; contact with authors and relevant pharmaceutical companies.

STUDY SELECTION

Eligible trials were randomised clinical trials comparing hydroxyethyl starch 130/0.38-0.45 with either crystalloid or human albumin in patients with sepsis. Published and unpublished trials were included irrespective of language and predefined outcomes.

DATA EXTRACTION

Two reviewers independently assessed studies for inclusion and extracted data on methods, interventions, outcomes, and risk of bias. Risk ratios and mean differences with 95% confidence intervals were estimated with fixed and random effects models.

RESULTS

Nine trials that randomised 3456 patients with sepsis were included. Overall, hydroxyethyl starch 130/0.38-0.45 versus crystalloid or albumin did not affect the relative risk of death (1.04, 95% confidence interval 0.89 to 1.22, 3414 patients, eight trials), but in the predefined analysis of trials with low risk of bias the relative risk of death was 1.11 (1.00 to 1.23, trial sequential analysis (TSA) adjusted 95% confidence interval 0.95 to 1.29, 3016 patients, four trials). In the hydroxyethyl starch group, renal replacement therapy was used more (1.36, 1.08 to 1.72, TSA adjusted 1.03 to 1.80, 1311 patients, five trials), and the relative risk of acute kidney injury was 1.18 (0.99 to 1.40, TSA adjusted 0.90 to 1.54, 994 patients, four trials). More patients in the hydroxyethyl starch group were transfused with red blood cells (1.29, 1.13 to 1.48, TSA adjusted 1.10 to 1.51, 973 patients, three trials), and more patients had serious adverse events (1.30, 1.02 to 1.67, TSA adjusted 0.93 to 1.83, 1069 patients, four trials). The transfused volume of red blood cells did not differ between the groups (mean difference 65 mL, 95% confidence interval -20 to 149 mL, three trials).

CONCLUSION

In conventional meta-analyses including recent trial data, hydroxyethyl starch 130/0.38-0.45 versus crystalloid or albumin increased the use of renal replacement therapy and transfusion with red blood cells, and resulted in more serious adverse events in patients with sepsis. It seems unlikely that hydroxyethyl starch 130/0.38-0.45 provides overall clinical benefit for patients with sepsis.

Fluid resuscitation with 6 % hydroxyethyl starch (130/0.4 and 130/0.42) in acutely ill patients: systematic review of effects on mortality and treatment with renal replacement therapy

PURPOSE

To determine whether fluid resuscitation of acutely ill adults with 6 % hydroxyethyl starch (6 % HES 130) with a molecular weight of 130 kD and a molar substitution ratio of approximately 0.4 (6 % HES 130) compared with other resuscitation fluids results in a difference in the relative risk of death or treatment with renal replacement therapy (RRT).

METHODS

Systematic review and meta-analysis of randomized controlled trials comparing intravascular fluids for resuscitation of hospitalised adults that reported mortality or treatment with RRT. The risk of bias was assessed independently by two reviewers and meta-analysis was performed using random effects.

RESULTS

Thirty-five trials enrolling 10,391 participants were included. The three largest trials had the lowest risk of bias, were published (or completed) in 2012, and together enrolled 77 % of all participants. Death occurred in 928 of 4,691 patients (19.8 %) in the 6 % HES 130 group versus 871 of 4,720 (18.5 %) in the control fluid groups relative risk (RR) in the 6 % HES 130 group 1.08, 95 % confidence interval (CI) 1.00 to 1.17, I (2) = 0 %). Treatment with RRT occurred in 378 of 4,236 patients (8.9 %) in the 6 % HES 130 group versus 306 of 4,260 (7.2 %) in the control fluid group (RR in the 6 % HES 130 group 1.25, 95 % CI 1.08 to 1.44, I (2) = 0 %).

CONCLUSIONS

The quality and quantity of data evaluating 6 % hydroxyethyl starch (130/0.4 and 130/0.42) as a resuscitation fluid has increased in the last 12 months. Patients randomly assigned to resuscitation with 6 %HES 130 are at significantly increased risk of being treated with RRT.

Albumin infusion improves outcomes of patients with spontaneous bacterial peritonitis: a meta-analysis of randomized trials

BACKGROUND & AIMS

Renal impairment increases mortality among patients with spontaneous bacterial peritonitis (SBP), despite administration of non-nephrotoxic antibiotics. Albumin infusion has been reported to reduce renal impairment and mortality in patients with SBP. We performed a meta-analysis of randomized controlled trials (RCTs) to quantify the effect of albumin infusion on renal impairment and mortality in patients with SBP.

METHODS

We searched MEDLINE, EMBASE, the Cochrane Library, and ClinicalTrials.gov for RCTs that evaluated albumin treatment for patients with SBP; we also performed searches by additional methods. Four trials of 288 total patients were included in our analysis. Data were quantitatively combined under a fixed-effects model.

RESULTS

We found no evidence of statistically significant heterogeneity or publication bias among the studies analyzed. Albumin was compared with no albumin in 3 trials and with artificial colloid in 1 trial. All patients received antibiotics. The incidence of renal impairment in control groups was 44 of 144 (30.6%), compared with 12 of 144 (8.3%) in groups given albumin. The pooled odds ratio for a reduction in renal impairment after albumin infusion was 0.21 (95% confidence interval, 0.11-0.42). Odds ratios for renal impairment after albumin therapy ranged from 0.19-0.30 among the individual studies. Mortality among controls was 51 of 144 (35.4%), compared with 23 of 144 (16.0%) among patients who received albumin. The pooled odds ratio for decreased mortality after infusion of albumin was 0.34 (95% confidence interval, 0.19-0.60). Odds ratios for mortality in individual RCTs ranged from 0.16-0.55.

CONCLUSIONS

In a meta-analysis of 4 RCTs (288 patients), albumin infusion prevented renal impairment and reduced mortality among patients with SBP.

Hypovolemic shock resuscitation

Several changes in the way patients with hemorrhagic shock are resuscitated have occurred over the past decades, including permissive hypotension, minimal crystalloid resuscitation, earlier blood transfusion, and higher plasma and platelet-to-red cell ratios. Hemostatic adjuncts, such as tranexamic acid and prothrombin complex, and the use of new methods of assessing coagulopathy are also being incorporated into resuscitation of the bleeding patient. These ideas have been incorporated by many trauma centers into institutional massive transfusion protocols, and adoption of these protocols has resulted in improvements in mortality and morbidity. This article discusses each of these new resuscitation strategies and the evidence supporting their use.

Systematic analysis of hydroxyethyl starch (HES) reviews: proliferation of low-quality reviews overwhelms the results of well-performed meta-analyses

PURPOSE

Hydroxyethyl starch (HES) is a synthetic colloid used widely for resuscitation despite the availability of safer, less costly fluids. Numerous HES reviews have been published that may have influenced clinicians' practice. We have therefore examined the relationship between the methodological quality of published HES reviews, authors' potential conflicts of interest (pCOI) and the recommendations made.

METHODS

Systematic analysis of reviews on HES use.

RESULTS

Between 1975 and 2010, 165 reviews were published containing recommendations for or against HES use. From the 1990s onwards, favorable reviews increased from two to eight per year and HES's share of the artificial colloid market tripled from 20 to 60 %. Only 7 % (12/165) of these reviews of HES use contained meta-analyses; these 7 % had higher Overview Quality Assessment Questionnaire (OQAQ) scores [median (range) 6.5 (3-7)] than reviews without meta-analysis [2 (1-4); p < 0.001]. The rates of recommending against HES use are 83 % (10/12) in meta-analyses and 20 % (31/153) in reviews without meta-analysis (p < 0.0001). Fourteen authors published the majority (70/124) of positive reviews, and ten of these 14 had or have since developed a pCOI with various manufacturers of HES.

CONCLUSIONS

Low-quality HES reviews reached different conclusions than high-quality meta-analyses from independent entities, such as Cochrane Reviews. The majority of these low-quality positive HES reviews were written by a small group of authors, most of whom had or have since established ties to industry. The proliferation of positive HES reviews has been associated with increased utilization of an expensive therapy despite the lack of evidence for meaningful clinical benefit and increased risks. Clinicians need to be more informed that marketing efforts are potentially influencing scientific literature.

Effect of molecular weight and substitution on tissue uptake of hydroxyethyl starch: a meta-analysis of clinical studies

BACKGROUND

Intravenously infused hydroxyethyl starch (HES) can be found in urine, plasma and tissues. HES remaining in plasma and tissues is thought to increase the risk of clinical complications. HES solutions of lower molecular weight and substitution have been developed to increase urinary excretion and reduce plasma persistence. However, their effect on tissue uptake of HES has not been investigated in human subjects.

OBJECTIVE

Our objective was to test the hypothesis that lower molecular weight and substitution decrease tissue uptake of HES.

DATA SOURCES

Computer searches were performed of MEDLINE; EMBASE; the Cochrane Library; meeting abstract databases in surgery, anaesthesiology and intensive care; ClinicalTrials.gov; and Google. Supplementary sources were reference lists and electronic tables of journal contents. No time period or language restrictions were imposed.

STUDY SELECTION

Clinical studies were eligible for inclusion in the meta-analysis, if data were reported both for cumulative urinary excretion of HES over 24 hours after infusion and for plasma HES concentration at 24 hours.

DATA EXTRACTION

Data were extracted on 24-hour urinary excretion of HES, 24-hour HES plasma concentration, plasma volume, HES molecular weight and substitution, study design, type and demographics of subjects, indication for fluid infusion, and HES infusion regimen. Tissue uptake of HES was computed as the difference between the infused dose and the sum of urinary excretion and residual plasma HES at 24 hours.

DATA SYNTHESIS

Twenty-five clinical studies totalling 287 subjects were included. Tissue uptake of low-molecular-weight HES (≤200 kD) was 42.3% (95% confidence interval [CI] 39.6, 45.0) compared with 24.6% (CI 17.8, 31.4) for high-molecular-weight HES (p < 0.001). Similarly, tissue uptake of lower-substitution HES (≤0.5) was 42.4% (CI 39.5, 45.3) versus 26.6% (CI 19.6, 33.6) for higher-substitution HES (p < 0.001). Among the three most often investigated single HES solutions, tissue uptake of 130/0.4 (42.6%; CI 35.0, 50.2) and HES 200/0.5 (43.3%; CI 39.4, 47.2) closely coincided, whereas uptake of HES 450/0.7 (22.2%; CI 14.8, 29.6) was lower (p = 0.001 and p < 0.001, respectively).

CONCLUSIONS

This meta-analysis did not support the hypothesis that lower molecular weight and substitution decrease tissue uptake of HES. Further clinical studies of HES tissue uptake are needed.

[Risk factors for postoperative acute kidney injury in a cohort of 2378 patients from 59 hospitals]

OBJECTIVES

To assess risk factors for postoperative acute kidney injury (AKI) in adults with normal renal function hospitalized for major surgery. To analyze mortality and length of hospital stay in patients who develop postoperative AKI.

PATIENTS AND METHODS

Data for analysis were drawn from the 2006 ARISCAT study. The dependent variable was postoperative AKI defined as a decline in renal function demonstrated by a rise in plasma creatinine level to twice the baseline measurement or a 50% reduction in the glomerular filtration rate. Bivariate and multivariate analyses were used to identify preoperative and intraoperative risk factors.

RESULTS

We analyzed 2378 of the ARISCAT cases, which had been enrolled from 59 participating hospitals; 25 patients (1.1%) developed AKI. Analysis identified 5 risk factors: age, peripheral arterial disease, type of surgical incision, blood loss, and infusion of colloids. The area under the receiver operating characteristic curve was 0.88% (95% confidence interval, 0.79%-0.69%). Duration of hospital stay was longer for patients with postoperative AKI (21.8 days, vs 5.5 days for other patients; P=.007). Mortality was higher in patients with AKI at 30 days (36% vs 0.9%) and at 3 months (48% vs 1.7%).

CONCLUSIONS

The incidence of postoperative AKI was slightly over 1%. Knowledge of postoperative AKI risk factors can facilitate the planning of surgical interventions and anesthesia to reduce subsequent morbidity and mortality and length of hospital stay.

Hydroxyethylstarch in cryopreservation - mechanisms, benefits and problems

As the progress of regenerative medicine places ever greater attention on cryopreservation of (stem) cells, tried and tested cryopreservation solutions deserve a second look. This article discusses the use of hydroxyethyl starch (HES) as a cryoprotectant. Charting carefully the recorded uses of HES as a cryoprotectant, in parallel to its further clinical use, indicates that some HES subtypes are a useful supplement to dimethysulfoxide (DMSO) in cryopreservation. However, we suggest that the most common admixture ratio of HES and DMSO in cryoprotectant solutions has been established by historical happenstance and requires further investigation and optimization.

Consensus statement of the ESICM task force on colloid volume therapy in critically ill patients

PURPOSE

Colloids are administered to more patients than crystalloids, although recent evidence suggests that colloids may possibly be harmful in some patients. The European Society of Intensive Care Medicine therefore assembled a task force to compile consensus recommendations based on the current best evidence for the safety and efficacy of the currently most frequently used colloids--hydroxyethyl starches (HES), gelatins and human albumin.

METHODS

Meta-analyses, systematic reviews and clinical studies of colloid use were evaluated for the treatment of volume depletion in mixed intensive care unit (ICU), cardiac surgery, head injury, sepsis and organ donor patients. Clinical endpoints included mortality, kidney function and bleeding. The relevance of concentration and dosage was also assessed. Publications from 1960 until May 2011 were included. The quality of available evidence and strength of recommendations were based on the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach.

RECOMMENDATIONS AND CONCLUSIONS

We recommend not to use HES with molecular weight ≥ 200 kDa and/or degree of substitution >0.4 in patients with severe sepsis or risk of acute kidney injury and suggest not to use 6% HES 130/0.4 or gelatin in these populations. We recommend not to use colloids in patients with head injury and not to administer gelatins and HES in organ donors. We suggest not to use hyperoncotic solutions for fluid resuscitation. We conclude and recommend that any new colloid should be introduced into clinical practice only after its patient-important safety parameters are established.

[Volume replacement in intensive care medicine]

Volume substitution represents an essential component of intensive care medicine. The amount of fluid administered, the composition and the timing of volume replacement seem to affect the morbidity and mortality of critically ill patients. Although restrictive volume strategies bear the risk of tissue hypoperfusion and tissue hypoxia in hemodynamically unstable patients liberal strategies favour the development of avoidable hypervolemia with edema and resultant organ dysfunction. However, neither strategy has shown a consistent benefit. In order to account for the heavily varying oxygen demand of critically ill patients, a goal-directed, demand-adapted volume strategy is proposed. Using this strategy, volume replacement should be aligned to the need to restore tissue perfusion and the evidence of volume responsiveness. As the efficiency of volume resuscitation for correction of tissue hypoxia is time-dependent, preload optimization should be completed in the very first hours. Whether colloids or crystalloids are more suitable for this purpose is still controversially discussed. Nevertheless, a temporally limited use of colloids during the initial stage of tissue hypoperfusion appears to represent a strategy which uses the greater volume effect during hypovolemia while minimizing the risks for adverse reactions.

Are renal adverse effects of hydroxyethyl starches merely a consequence of their incorrect use?

BACKGROUND

Clinical studies such as VISEP-study, which show a negative outcome after the administration of hydroxyethyl starch (HES), are often criticized for an "incorrect" use of HES. It is argued that HES used in these studies differed from usual practice and that recommendations for maximal dosage, duration, and creatinine values were ignored, not enough "free water" was provided and more modern HES solutions should have been used. These comments imply that renal adverse events in clinical studies are the consequence of an inappropriate use of HES. We therefore searched for evidence whether these suggested measures are beneficial.

METHODS

Narrative review; post hoc statistical analysis of epidemiologic data from a representative nationwide survey.

RESULTS

It is evident from published clinical studies that the renal risk of HES increases with cumulative dose and rising serum creatinine values, but no safe upper dose limit or creatinine threshold is known. Suggested safety measures were not able to prevent HES-induced renal failure in clinical studies. Published clinical trials with modern HES solutions are not suited to prove its assumed increased safety because of small sample sizes, low cumulative doses, short observation periods, and inadequate control fluids. Use of HES in a clinical study with negative outcomes conformed to clinical practice, indicating the generalizability of study results.

CONCLUSION

There is no evidence for the assumption that HES-associated renal impairment may be avoided by accompanying measures. Because HES use does not improve clinical outcome, the question arises whether it should be used at all in patients at risk.

The Crystalloid versus Hydroxyethyl Starch Trial: protocol for a multi-centre randomised controlled trial of fluid resuscitation with 6% hydroxyethyl starch (130/0.4) compared to 0.9% sodium chloride (saline) in intensive care patients on mortality

PURPOSE

The intravenous fluid 6% hydroxyethyl starch (130/0.4) (6% HES 130/0.4) is used widely for resuscitation but there is limited information on its efficacy and safety. A large-scale multi-centre randomised controlled trial (CHEST) in critically ill patients is currently underway comparing fluid resuscitation with 6% HES 130/0.4 to 0.9% sodium chloride on 90-day mortality and other clinically relevant outcomes including renal injury. This report describes the study protocol.

METHODS

CHEST will recruit 7,000 patients to concealed, random, parallel assignment of either 6% HES 130/0.4 or 0.9% sodium chloride for all fluid resuscitation needs whilst in the intensive care unit (ICU). The primary outcome will be all-cause mortality at 90 days post-randomisation. Secondary outcomes will include incident renal injury, other organ failures, ICU and hospital mortality, length of ICU stay, quality of life at 6 months, health economic analyses and in patients with traumatic brain injury, functional outcome. Subgroup analyses will be conducted in four predefined subgroups. All analyses will be conducted on an intention-to-treat basis.

RESULTS AND CONCLUSIONS

The study run-in phase has been completed and the main trial commenced in April 2010. CHEST should generate results that will inform and influence prescribing of this commonly used resuscitation fluid.

Innovations in treating aortic diseases: the abdominal aorta

Patients with an abdominal aortic aneurysm (AAA) could benefit from earlier diagnosis to improve long-term outcomes. Candidate serum biomarkers for earlier AAA diagnosis include D-dimer, fibrinogen, low-density lipoprotein, high-density lipoprotein, lipoprotein(a), and the proteolytic enzymes known as matrix metalloproteinases. Furthermore, biomarkers such as brain natriuretic peptide significantly stratify perioperative risk in AAA repair. Statins significantly improve outcomes after AAA repair. They may also significantly slow AAA growth to allow pharmacologic arrest of AAA development. Recent trials have focused attention on fluid management for AAA repair. Although restrictive fluid management may significantly improve clinical outcomes, current evidence does not clearly support crystalloid or colloid for AAA repair. There may be an increased risk of renal dysfunction associated with hetastarch therapy. Endovascular repair has revolutionized the clinical management of AAAs. Recent trials have shown its significant outcome advantages. Furthermore, it is also applicable in high-risk operative cohorts and, in the future, may be suited for earlier AAA repair. This technology continues to advance with the development of branched and fenestrated grafts as well as total percutaneous endovascular AAA repair. Regardless of these advances, the clinical management of endoleaks will remain a major clinical focus. Taken together, these advances in the management of AAAs likely will significantly influence future clinical approaches to this challenging patient cohort.

Hyperoncotic colloids and acute kidney injury: a meta-analysis of randomized trials

Introduction

It has been hypothesized that hyperoncotic colloids might contribute to acute kidney injury (AKI). However, the validity of this hypothesis remains unclear.

Methods

A meta-analysis was conducted of randomized controlled trials evaluating AKI after infusion of hyperoncotic albumin and hydroxyethyl starch (HES) solutions. Mortality was a secondary endpoint. Eligible trials were sought by multiple methods, and the pooled odds ratios (OR) for AKI and death and 95% confidence intervals (CI) were computed under a random effects model.

Results

Eleven randomized trials with a total of 1220 patients were included: 7 evaluating hyperoncotic albumin and 4 hyperoncotic HES. Clinical indications were ascites, surgery, sepsis and spontaneous bacterial peritonitis. Hyperoncotic albumin decreased the odds of AKI by 76% (OR, 0.24; CI, 0.12-0.48; P < 0.0001), while hyperoncotic HES increased those odds by 92% (OR, 1.92; CI, 1.31-2.81; P = 0.0008). Parallel effects on mortality were observed, with hyperoncotic albumin reducing the odds of death by 48% (OR, 0.52; CI, 0.28-0.95; P = 0.035) and hyperoncotic HES raising those odds by 41% (OR, 1.41; CI, 1.01-1.96; P = 0.043).

Conclusions

This meta-analysis does not support the hypothesis that hyperoncotic colloid solutions per se injure the kidney. Renal effects appear instead to be colloid-specific, with albumin displaying renoprotection and HES showing nephrotoxicity.

[Results of studies in critical care medicine in the year 2009 : update]

Critical care medicine plays an important role for the medical and economic success of hospitals. Knowledge and implementation of recent relevant studies are prerequisites for high quality intensive care medicine. The aim of the present manuscript is to present an overview of the most important publications in intensive care medicine in 2009 and comment on their clinical relevance. It has to be recognized that the cited studies are chosen according to the view of the authors. In 2009 many large randomized studies with high patient numbers were published. Main topics in 2009 were the therapy of lung failure, analgosedation and sepsis therapy. New trends are bedside echocardiography and telemedicine. Unfortunately, a magic bullet has not been identified last year. The focus is still on team education and guideline-assisted therapy.

Prevention, diagnosis, therapy and follow-up care of sepsis: 1st revision of S-2k guidelines of the German Sepsis Society (Deutsche Sepsis-Gesellschaft e.V. (DSG)) and the German Interdisciplinary Association of Intensive Care and Emergency Medicine (Deutsche Interdisziplinäre Vereinigung für Intensiv- und Notfallmedizin (DIVI))

Practice guidelines are systematically developed statements and recommendations that assist the physicians and patients in making decisions about appropriate health care measures for specific clinical circumstances taking into account specific national health care structures. The 1^st revision of the S-2k guideline of the German Sepsis Society in collaboration with 17 German medical scientific societies and one self-help group provides state-of-the-art information (results of controlled clinical trials and expert knowledge) on the effective and appropriate medical care (prevention, diagnosis, therapy and follow-up care) of critically ill patients with severe sepsis or septic shock. The guideline had been developed according to the “German Instrument for Methodological Guideline Appraisal” of the Association of the Scientific Medical Societies (AWMF). In view of the inevitable advancements in scientific knowledge and technical expertise, revisions, updates and amendments must be periodically initiated. The guideline recommendations may not be applied under all circumstances. It rests with the clinician to decide whether a certain recommendation should be adopted or not, taking into consideration the unique set of clinical facts presented in connection with each individual patient as well as the available resources.

Effects of different fibrinogen concentrations on blood loss and coagulation parameters in a pig model of coagulopathy with blunt liver injury

INTRODUCTION

The early application of fibrinogen could potentially reverse haemodilution-induced coagulopathy, although the impact of varying concentrations of fibrinogen to reverse dilutional coagulopathy has not been studied in vivo. We postulated that fibrinogen concentration is correlated with blood loss in a pig model of coagulopathy with blunt liver injury.

METHODS

Coagulopathy was induced in 18 anaesthetized pigs (32 +/- 1.6 kg body weight) by replacing 80% of blood volume with hydroxyethylstarch 130/0.4 and Ringer's lactated solution, and re-transfusion of erythrocytes. Animals were randomly assigned to receive either 70 mg kg-1 (F-70) or 200 mg kg-1 (F-200) fibrinogen or placebo before inducing blunt liver injury using a force of 225 +/- 26 Newton. Haemodynamics, coagulation parameters and blood loss were monitored for 2 hours. After death, histological examination of internal organs was performed to assess the presence of emboli and the equality of liver injury.

RESULTS

Plasma dilution caused severe coagulopathy. Measured by thromboelastography fibrinogen restored coagulation dose-dependently. Total blood loss was significantly lower and survival better in both fibrinogen groups as compared to controls (P < 0.05). Between the F-70 (1317 +/- 113 ml) and the F-200 group (1155 +/- 232 ml) no significant difference in total blood loss could be observed, despite improved coagulation parameters in the F-200 group (P < 0.05). Microscopy revealed even injury pattern and no (micro) thrombi for either group.

CONCLUSIONS

Restoring fibrinogen with 70 or 200 mg kg-1 after severe dilutional coagulopathy safely improved coagulation and attenuated blood loss after experimental blunt liver trauma. The higher dosage of fibrinogen was not associated with a further reduction in blood loss.

Resuscitation with low volume hydroxyethylstarch 130 kDa/0.4 is not associated with acute kidney injury

INTRODUCTION

Acute kidney injury (AKI) in the ICU is associated with poorer prognosis. Hydroxyethylstarch (HES) solutions are fluid resuscitation colloids frequently used in the ICU with controversial nephrotoxic adverse effects. Our study objective was to evaluate HES impact on renal function and organ failures.

METHODS

This observational retrospective study included 363 patients hospitalized for more than 72 hours in our ICU. A hundred and sixty eight patients received HES during their stay and 195 did not. We recorded patients' baseline characteristics on admission and type and volume of fluid resuscitation during the first 3 weeks of ICU stay. We also noted the evolution of urine output, the risk of renal dysfunction, injury to the kidney, failure of kidney function, loss of kidney function and end-stage kidney disease (RIFLE) classification and sepsis related organ failure assessment (SOFA) score over 3 weeks.

RESULTS

Patients in the HES group were more severely ill on admission but AKI incidence was similar, as well as ICU mortality. The evolution of urine output (P = 0.74), RIFLE classification (P = 0.44) and SOFA score (P = 0.23) was not different. However, HES volumes administered were low (763+/-593 ml during the first 48 hours).

CONCLUSIONS

Volume expansion with low volume HES 130 kDa/0.4 was not associated with AKI.