[The design of the VISEP trial. Critical appraisal]

Hydroxyeyhyl starch: Controversies revisited

Hydroxyethyl starch (HES) family has been one of the cornerstones in fluid management for over four decades. Recent evidence from clinical studies and meta-analyses has raised few concerns about the safety of these fluids, especially in certain subpopulations of patients. High-quality clinical trials and meta-analyses have emphasized nephrotoxic effects, increased risk of bleeding, and a trend toward higher mortality in these patients after the use of HES solutions. Scientific evidence was derived from international guidelines, aggregated research literature, and opinion-based evidence was obtained from surveys and other activities (e.g., internet postings). On critical analysis of the current data available, it can be summarized that further large scale trials are still indicated before HES can be discarded.

Glucose control in the ICU: is there a time for more ambitious targets again?

During the last 2 decades, the treatment of hyperglycemia in critically ill patients has become one of the most discussed topics in the intensive medicine field. The initial data suggesting significant benefit of normalization of blood glucose levels in critically ill patients using intensive intravenous insulin therapy have been challenged or even neglected by some later studies. At the moment, the need for glucose control in critically ill patients is generally accepted yet the target glucose values are still the subject of ongoing debates. In this review, we summarize the current data on the benefits and risks of tight glucose control in critically ill patients focusing on the novel technological approaches including continuous glucose monitoring and its combination with computer-based algorithms that might help to overcome some of the hurdles of tight glucose control. Since increased risk of hypoglycemia appears to be the major obstacle of tight glucose control, we try to put forward novel approaches that may help to achieve optimal glucose control with low risk of hypoglycemia. If such approaches can be implemented in real-world practice the entire concept of tight glucose control may need to be revisited.

[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.

The association of age, illness severity, and glycemic status in a pediatric intensive care unit

OBJECTIVE

Tight glycemic control in critically ill children is controversial. The benefits of controlling hyperglycemia may be offset by the risk of hypoglycemia on the immature brain. Both age and severity of illness may influence the risks and benefits of tight glycemic control. We hypothesize that rates of hypoglycemia (blood glucose <60 mg/dL) and hyperglycemia (blood glucose >150 mg/dL) in children will correlate with age and illness severity.

DESIGN

Retrospective chart review.

SETTING

Thirty-two-bed university-affiliated pediatric intensive care unit.

PATIENTS

Children <19 yrs old admitted between January and September 2006.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

We recorded all blood glucose measurements for up to 10 days of each pediatric intensive care unit visit and assessed rates of hypoglycemia and hyperglycemia based on age, medical vs. surgical therapy, length of stay, therapeutic intervention (Therapeutic Intervention Scoring System), and illness severity (Pediatric Risk of Mortality III). A total of 8853 blood glucose values in 616 patients were recorded. Spontaneous hypoglycemia was noted in 18.8% of patients <1 yr compared with 5.1% to 11.3% of patients in older age groups. Hyperglycemia occurred in 47% of patients <1 yr, which increased to 58.9% in patients 13-18 yrs. Rates of hypoglycemia were not affected by medical/surgical status. Surgical patients had an increased risk of hyperglycemia. Rates of hypo- and hyperglycemia increased with higher Pediatric Risk of Mortality III, Therapeutic Intervention Scoring System, length of stay, and days of mechanical ventilation. Increased rates of hypo-/hyperglycemia were observed in patients who died.

CONCLUSIONS

The youngest patients are at higher risk for spontaneous hypoglycemia, whereas hyperglycemia occurs more often in the older ages. Higher rates of hypo-/hyperglycemia were noted in sicker patients and in those requiring more therapeutic interventions. Our results suggest that special consideration should be given to the safety of the youngest patients given their higher risk of hypoglycemia if an investigation of tight glycemic control is performed.

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.

Analytic review: glucose controversies in the ICU

Hyperglycemia is common in critical illness and has been associated with increased morbidity and mortality. An era of tight glucose control began when intensive insulin therapy was shown to improve outcomes in a single-center randomized trial. More recently, with the publication of additional studies, questions have been raised regarding the efficacy and safety of intensive glycemic management. This article will review the biologic mechanisms that may help us understand why and how hyperglycemia and insulin are relevant in critical illness. We will then explore insights gleaned from available clinical trials. Finally, we will discuss specific areas of controversy that relate to the implementation of glycemic control in the intensive care unit, such as the ideal glucose target and the importance of hypoglycemia.

Early fluid resuscitation with hyperoncotic hydroxyethyl starch 200/0.5 (10%) in severe burn injury

Introduction

Despite large experience in the management of severe burn injury, there are still controversies regarding the best type of fluid resuscitation, especially during the first 24 hours after the trauma. Therefore, our study addressed the question whether hyperoncotic hydroxyethyl starch (HES) 200/0.5 (10%) administered in combination with crystalloids within the first 24 hours after injury is as effective as 'crystalloids only' in severe burn injury patients.

Methods

30 consecutive patients were enrolled to this prospective interventional open label study and assigned either to a traditional 'crystalloids only' or to a 'HES 200/0.5 (10%)' volume resuscitation protocol. Total amount of fluid administration, complications such as pulmonary failure, abdominal compartment syndrome, sepsis, renal failure and overall mortality were assessed. Cox proportional hazard regression analysis was performed for binary outcomes and adjustment for potential confounders was done in the multivariate regression models. For continuous outcome parameters multiple linear regression analysis was used.

Results

Group differences between patients receiving crystalloids only or HES 200/0.5 (10%) were not statistically significant. However, a large effect towards increased overall mortality (adjusted hazard ratio 7.12; P = 0.16) in the HES 200/0.5 (10%) group as compared to the crystalloids only group (43.8% versus 14.3%) was present. Similarly, the incidence of renal failure was 25.0% in the HES 200/0.5 (10%) group versus 7.1% in the crystalloid only group (adjusted hazard ratio 6.16; P = 0.42).

Conclusions

This small study indicates that the application of hyperoncotic HES 200/0.5 (10%) within the first 24 hours after severe burn injury may be associated with fatal outcome and should therefore be used with caution.

Trial registration

NCT01120730.

Pro/con debate: should synthetic colloids be used in patients with septic shock?

You have recently heard reports that synthetic colloids may be associated with renal failure and other morbidities in certain populations of critically ill patients. You have been asked by the hospital chief of staff whether there should be a suspension of the use of synthetic colloids until further information is available. You need to make a decision.

Shock settico

Lo shock settico corrisponde all’associazione di un’infezione e di un’insufficienza emodinamica, eventualmente associata ad altri deficit viscerali. Le definizioni assimilano spesso lo shock settico alla sepsi grave, la cui insufficienza emodinamica è considerata reversibile. I fondamenti del trattamento si basano su misure che si devono applicare in tempi brevi: il trattamento specifico, che corrisponde alla lotta contro l’agente infettivo, e il trattamento sintomatico, in particolare mediante il ripristino di un’emodinamica efficace. L’aumento del numero delle infezioni gravi e degli shock settici nei paesi industrializzati è stato all’origine di sforzi considerevoli allo scopo di migliorarne la gestione. In particolare, il frutto delle riflessioni congiunte di diverse società scientifiche è stato formalizzato in raccomandazioni, riassunte in procedure. In effetti, la strategia che mira a un miglioramento delle pratiche sembra ridurre la mortalità legata alle infezioni. Alcuni ostacoli compromettono tuttavia il loro uso, dal riconoscimento del problema all’organizzazione delle cure.

[Glycemic control in sepsis and septic shock: friend or foe?]

INTRODUCTION

Intensive care patients commonly suffer from hyperglycemia. Evidence is growing that strictly maintaining normoglycemia by intensive insulin therapy (IIT) ameliorates outcome in these patients. Whether or not this also holds true for patients with sepsis and septic shock is the issue of this post-hoc analysis of the database (2,748 patients) of 2 recent prospective clinical trials.

MATERIAL AND METHODS

A total of 950 patients suffering from sepsis were identified and of these 462 fulfilled the diagnostic criteria of septic shock upon admission to the intensive care unit (ICU). Patients were treated by either IIT [mean glycemia 5.88 mmol/l (106 mg/dl)] or conventional glucose management [mean glycemia 8.44 mmol/l (152 mg/dl)].

RESULTS

Under IIT the mortality of patients treated for more than 3 days in the ICU was lowered by 7.6% (p=0.03) in septic patients and by 8.7% (p=0.08) in septic shock patients. Polyneuropathy occurred less frequently under IIT compared to conventional glucose management (sepsis -9.8%, septic shock -14%; p<0.001). The incidence of acute renal failure was not affected by either treatment regimen (sepsis -3.3%, septic shock -3.1%; p<0.25). Intensive insulin therapy was associated with an increased risk of hypoglycemia (sepsis +16.7%, septic shock +18.8; p<0.0001) which did not, however, directly affect morbidity nor mortality.

CONCLUSIONS

These data suggest that IIT improves outcome of patients with sepsis or septic shock. Hypoglycemia is a frequent complication, but its clinical relevance remains to be defined.

Preferences for colloid use in Scandinavian intensive care units

BACKGROUND

Fluid resuscitation is a frequent intervention in intensive care. Colloids are widely used, but recent data suggest harm by some of these solutions. This calls for more clinical studies on this matter, but the current preferences for colloid use in Scandinavian intensive care units (ICUs) are unknown.

METHODS

In March-May 2007, 120 Scandinavian ICUs were invited to answer a web-based survey consisting of 18 questions on types of colloids, indications, contraindications and rationale of use.

RESULTS

Seventy-three ICUs, of which 31 were university hospital units, answered the questionnaire. Most ICUs used both synthetic and natural colloids, and hydroxyethyl starch (HES) 130/0.4 was the preferred colloid in 59 units. Eleven ICUs had protocols for colloid use. The most frequent indication was second-line fluid for hypovolaemia, but one in three ICUs used colloids as first-line fluid. Thirty-five ICUs had contraindications, which were mainly for the use of synthetic colloids (acute renal failure 25 units, bleeding 15 units). Most units based the use of colloids on theoretical knowledge and tradition. Sixty-five and 54 ICUs were ready to change colloid use based on data from randomised trials of ICU patients showing changes in mortality or renal function, respectively.

CONCLUSION

Most Scandinavian ICUs use both synthetic and natural colloids, but HES 130/0.4 is by far the preferred colloid. Few units have protocols for colloid use, but most use them for hypovolaemia, and the majority have no contraindications. Most ICUs are ready to change colloid use if randomised trials in ICU patients show changes in mortality or renal function.

Diagnosis and treatment of severe sepsis

The burden of infection in industrialized countries has prompted considerable effort to improve the outcomes of patients with sepsis. This has been formalized through the Surviving Sepsis Campaign 'bundles', derived from the recommendations of 11 professional societies, which have promoted global improvement in those practices whose primary goal it is to reduce sepsis-related death. However, difficulties remain in implementing all of the procedures recommended by the experts, despite the apparent pragmatism of those procedures. We summarize the main proposals made by the Surviving Sepsis Campaign and focus on the difficulties associated with making a proper diagnosis and supplying adequate treatment promptly to septic patients.

Evaluation of the VIA Blood Chemistry Monitor for Glucose in Healthy and Diabetic Volunteers

BACKGROUND

Manual methods of blood glucose monitoring are labor-intensive, costly, prone to error, and expose the caregiver to blood. The VIA(R) blood chemistry monitor for glucose can automatically measure plasma glucose (PG) every 5 minutes for 72 hours using blood sampled from a peripheral vein/artery or a central vein.

METHODS

VIA performance was evaluated in eight normal and five type 1 diabetic (T1DM) subjects in 15 separate experiments. The VIA device was connected to a peripheral vein and reported a PG value every 5 minutes during each 510-minute experiment. Blood samples were collected manually every 10 minutes and assayed using a HemoCue(R) beta-glucose analyzer (HC). Whole blood HC measurements were corrected to PG values. Paired HC/VIA measurements (n = 717) were analyzed.

RESULTS

Mean PG was 90 +/- 14 and 96 +/- 12 mg/dl in normal subjects and 194 +/- 64 and 173 +/- 48 mg/dl in T1DM subject as measured by the HC and VIA, respectively. Clark error grid analysis revealed 86% points in zone A, 11% points in zone B, and 2% points in zone D. Linear regression analysis yielded the following equation: VIA = 0.732 x HC + 30.5 (r(2) = 0.954). Residual analysis revealed a glucose-dependent bias between the HC and the VIA. VIA data were transformed using the linear regression equation to correct for bias. After the correction, the mean absolute relative difference between the VIA and the HC was less than 10%, and 99.6% of data were in zones A and B. The VIA was able to sample blood automatically every 5 minutes for more than 8 hours in the laboratory setting. On average, the VIA reported glucose values for 94% of the samples it attempted to obtain.

CONCLUSIONS

This study demonstrated that the VIA blood chemistry monitor for glucose can reliably sample blood frequently for a prolonged period of time safely and effectively in diabetic and nondiabetic volunteers. Agreement between the two devices was the closest at normal glucose concentrations. After correcting for a glucose-dependent bias between the devices, the MARD was consistently less than 10% for all glucose ranges.

Evidence for strict inpatient blood glucose control: time to revise glycemic goals in hospitalized patients

Inpatient hyperglycemia in patients with and without a history of diabetes is common and is associated with increased hospital morbidity and mortality. The objectives of this communication are to examine results of randomized clinical trials of strict inpatient glucose control in medical and surgical intensive care units and to provide guidelines for achieving and maintaining glycemic control in patients admitted to critical and noncritical settings. We propose a more conservative approach of glycemic control than current American Association of Clinical Endocrinology recommendations until results of prospective, multicenter, randomized studies become available.

„Base excess“

The base excess of blood (BE) plays an important role in the description of the acid-base status of a patient and is gaining in clinical interest. Apart from the Quick test, the age, the injury severity score and the Glasgow coma scale, the BE is becoming more and more important to identify, e. g. the risk of mortality for patients with multiple injuries. According to Zander the BE is calculated using the pH, pCO(2), haemoglobin concentration and the oxygen saturation of haemoglobin (sO(2)). The use of sO(2 )allows the blood gas analyser to determine only one value of BE, independent of the type of blood sample analyzed: arterial, mixed venous or venous. The BE and measurement of the lactate concentration (cLac) play an important role in diagnosing critically ill patients. In general, the change in BE corresponds to the change in cLac. If DeltaBE is smaller than DeltacLac the reason could be therapy with HCO(3)(-) but also with infusion solutions containing lactate. Physician are very familiar with the term BE, therefore, knowledge about an alkalizing or acidifying effect of an infusion solution would be very helpful in the treatment of patients, especially critically ill patients. Unfortunately, at present the description of an infusion solution with respect to BE has not yet been accepted by the manufacturers.