Hydroxyethylstarch deposits in human skin--a model for pruritus?

Does Hemodilution Enhance or Compromise Blood Coagulation?

The reduction in oxygen-carrying capacity during hemodilution is well tolerated by most patients. However, hemodilution not only decreases O2 transport capacity, but also may influence blood coagulation. Advanced hemodilution with crystalloids does not compromise blood coagulation and, with moderate hemodilution, even augmented blood coagulation may develop. In contrast, blood coagulation is compromised during hemodilution with colloids. The effect of human serum albumin and gelatin is relatively modest, but significantly more than during equivalent hemodilution with crystalloids. Dextran and hydroxyethyl starch compromise blood coagulation more. This results from reduction of factor VIII, a decrease in plasmatic coagulation, and an impairment of platelet function. For hydroxyethyl starch, molecular size and degree of substitution are crucial for the effect on blood coagulation, with hydroxyethyl starch (200,000/0.5) having the least effect. Furthermore, accelerated fibrin formation is observed during hemodilution with Dextran, hydroxyethyl starch, and gelatin with an altered fibrin structure. In vitro clot lysis is also increased with all colloids, but there are no reports on augmented in vivo fibrin degradation products. Besides the effect on intraoperative blood coagulation, the hemodynamic effectiveness, duration thereof, effect on microcirculation and edema formation, and, in particular, the effect on the hypercoagulable state in the postoperative period need to be considered in the choice of the replacement fluid during hemodilution and intraoperative blood loss.

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.

Adverse effects of hydroxyethyl starch (HES 130/0.4) on intestinal barrier integrity and metabolic function are abrogated by supplementation with Albumin

Background

Volume resuscitation with hydroxyethyl starch (HES) is controversially discussed and we recently showed that HES perfusion impairs endothelial and epithelial intestinal barrier integrity. Here we investigated whether Albumin containing HES solutions are superior to HES alone in maintaining intestinal barrier function.

Methods

An isolated perfused model of the mouse small intestine was used to investigate the effects of: (i) 3 % Albumin (Alb), (ii) 3 % HES or (iii) 1.5 % HES/1.5 % Albumin (HES/Alb). Intestinal morphology, cell damage, metabolic functions, fluid shifts and endothelial/epithelial barrier permeability were evaluated. Potentially involved signaling mechanisms (Erk1/2, Akt and Stat5 phosphorylation) were screened.

Results

HES induced histomorphological damage (p < 0.01 vs. Alb), by trend elevated the amount of luminal intestinal fatty acid binding protein and reduced galactose uptake (p < 0.001 vs. Alb). Luminal and lymphatic flow rates were increased (p < 0.001 vs. Alb), while vascular flow was decreased (p < 0.001 vs. Alb) during HES perfusion. HES also increased the vascular to luminal FITC-dextran transfer (p < 0.001 vs. Alb), pointing towards a fluid shift from the vascular to the luminal and lymphatic compartments during HES perfusion. Addition of Alb (HES/Alb) reversed all adverse effects of HES (p < 0.05 vs. HES), restored barrier integrity (p < 0.05 vs. HES) and improved metabolic function of the intestine (p < 0.001 vs. HES; p < 0.05 vs. Alb). Mechanistically, HES/Alb perfusion resulted in an increased phosphorylation of Erk1/2 and Akt kinases (p < 0.001 vs. HES), while Stat5 remained unchanged.

Conclusions

Albumin supplementation abrogates the adverse effects of HES in the intestine and underlying mechanism may function via phosphorylation of Erk1/2 and Akt. Albumin containing HES solutions are superior to HES alone and may improve the suitability of HES in the clinic.

Electronic supplementary material

The online version of this article (doi:10.1186/s12967-016-0810-3) contains supplementary material, which is available to authorized users.

Hydroxyethyl starch (HES 130/0.4) impairs intestinal barrier integrity and metabolic function: findings from a mouse model of the isolated perfused small intestine

BACKGROUND

The application of hydroxyethyl starch (HES) for volume resuscitation is controversially discussed and clinical studies have suggested adverse effects of HES substitution, leading to increased patient mortality. Although, the intestine is of high clinical relevance and plays a crucial role in sepsis and inflammation, information about the effects of HES on intestinal function and barrier integrity is very scarce. We therefore evaluated the effects of clinically relevant concentrations of HES on intestinal function and barrier integrity employing an isolated perfused model of the mouse small intestine.

METHODS

An isolated perfused model of the mouse small intestine was established and intestines were vascularly perfused with a modified Krebs-Henseleit buffer containing 3% Albumin (N=7) or 3% HES (130/0.4; N=7). Intestinal metabolic function (galactose uptake, lactate-to-pyruvate ratio), edema formation (wet-to-dry weight ratio), morphology (histological and electron microscopical analysis), fluid shifts within the vascular, lymphatic and luminal compartments, as well as endothelial and epithelial barrier permeability (FITC-dextran translocation) were evaluated in both groups.

RESULTS

Compared to the Albumin group, HES perfusion did not significantly change the wet-to-dry weight ratio and lactate-to-pyruvate ratio. However, perfusing the small intestine with 3% HES resulted in a significant loss of vascular fluid (p<0.01), an increased fluid accumulation in the intestinal lumen (p<0.001), an enhanced translocation of FITC-dextran from the vascular to the luminal compartment (p<0.001) and a significantly impaired intestinal galactose uptake (p<0.001). Morphologically, these findings were associated with an aggregation of intracellular vacuoles within the intestinal epithelial cells and enlarged intercellular spaces.

CONCLUSION

A vascular perfusion with 3% HES impairs the endothelial and epithelial barrier integrity as well as metabolic function of the small intestine.

Accumulation of hydroxyethyl starch in human and animal tissues: a systematic review

PURPOSE

To systematically review clinical and preclinical data on hydroxyethyl starch (HES) tissue storage.

METHODS

MEDLINE (PubMed) was searched and abstracts were screened using defined criteria to identify articles containing original data on HES tissue accumulation.

RESULTS

Forty-eight studies were included: 37 human studies with a total of 635 patients and 11 animal studies. The most frequent indication for fluid infusion was surgery accounting for 282 patients (45.9%). HES localization in skin was shown by 17 studies, in kidney by 12, in liver by 8, and in bone marrow by 5. Additional sites of HES deposition were lymph nodes, spleen, lung, pancreas, intestine, muscle, trophoblast, and placental stroma. Among major organs the highest measured tissue concentration of HES was in the kidney. HES uptake into intracellular vacuoles was observed by 30 min after infusion. Storage was cumulative, increasing in proportion to dose, although in 15% of patients storage and associated symptoms were demonstrated at the lowest cumulative doses (0.4 g kg(-1)). Some HES deposits were extremely long-lasting, persisting for 8 years or more in skin and 10 years in kidney. Pruritus associated with HES storage was described in 17 studies and renal dysfunction in ten studies. In one included randomized trial, HES infusion produced osmotic nephrosis-like lesions indicative of HES storage (p = 0.01) and also increased the need for renal replacement therapy (odds ratio, 9.50; 95% confidence interval, 1.09-82.7; p = 0.02). The tissue distribution of HES was generally similar in animals and humans.

CONCLUSIONS

Tissue storage of HES is widespread, rapid, cumulative, frequently long-lasting, and potentially harmful.

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.

Systematic review of randomized clinical trials on the use of hydroxyethyl starch for fluid management in sepsis

Background

Patients with sepsis typically require large resuscitation volumes, but the optimal type of fluid remains unclear. The aim of this systematic review was to evaluate current evidence on the effectiveness and safety of hydroxyethyl starch for fluid management in sepsis.

Methods

Computer searches of MEDLINE, EMBASE and the Cochrane Library were performed using search terms that included hydroxyethyl starch; hetastarch; shock, septic; sepsis; randomized controlled trials; and random allocation. Additional methods were examination of reference lists and hand searching. Randomized clinical trials comparing hydroxyethyl starch with other fluids in patients with sepsis were selected. Data were extracted on numbers of patients randomized, specific indication, fluid regimen, follow-up, endpoints, hydroxyethyl starch volume infused and duration of administration, and major study findings.

Results

Twelve randomized trials involving a total of 1062 patients were included. Ten trials (83%) were acute studies with observation periods of 5 days or less, most frequently assessing cardiorespiratory and hemodynamic variables. Two trials were designed as outcome studies with follow-up for 34 and 90 days, respectively. Hydroxyethyl starch increased the incidence of acute renal failure compared both with gelatin (odds ratio, 2.57; 95% confidence interval, 1.13–5.83) and crystalloid (odds ratio, 1.81; 95% confidence interval, 1.22–2.71). In the largest and most recent trial a trend was observed toward increased overall mortality among hydroxyethyl starch recipients (odds ratio, 1.35; 95% confidence interval, 0.94–1.95), and mortality was higher (p < 0.001) in patients receiving > 22 mL·kg^-1 hydroxyethyl starch per day than lower doses.

Conclusion

Hydroxyethyl starch increases the risk of acute renal failure among patients with sepsis and may also reduce the probability of survival. While the evidence reviewed cannot necessarily be applied to other clinical indications, hydroxyethyl starch should be avoided in sepsis.

Pharmacodynamics and organ storage of hydroxyethyl starch in acute hemodilution in pigs: influence of molecular weight and degree of substitution

OBJECTIVE

To determine the differential influence of molecular weight and the degree of substitution of HES solutions on pharmacodynamics and pharmacokinetics including organ storage in a model of acute hemodilution in pigs.

DESIGN

Prospective controlled randomized animal trial.

INTERVENTIONS

After bleeding, 20 ml/kg, animals were substituted with 6% HES preparations (200/0.62, 200/0.5, and 100/0.5).

MEASUREMENTS AND RESULTS

We did not observe any significant differences in the ability to sufficiently achieve plasma volume expansion and restoration of macrocirculation, nor maintenance of indicators of microcirculation between the groups. Urine production was significantly higher in HES-treated animals and highest in animals substituted with HES 100/0.5. Plasma clearance was measured under steady-state conditions with significantly reduced clearance for the HES 200/0.62 group compared with HES 100/0.5 and HES 200/0.5 (6.6 vs. 13.2 and 13.9 ml/min; P < or = 0.001), thus being dependent on the degree of substitution. Even after only 6 h, the amount of infused HES not detectable in either blood or urine was significantly higher in HES 200/0.62-treated animals (50.7% compared with HES 200/0.5 (28.8%), P = 0.020 and HES 100/0.5 (28.4%), P = 0.018), with its proportion rising over time. Finally, we could demonstrate considerable amounts of all HES solutions being stored in liver, kidney, lung, spleen and lymph nodes.

CONCLUSIONS

All preparations analyzed sufficiently restored macro- and microcirculation; however, for all solutions relevant tissue storage of HES was observed after only 6 h.

Hydroxyethyl starch-induced itch: relevance of light microscopic analysis of semi-thin sections and electron microscopy

BACKGROUND

Hydroxyethyl starch (HES) is widely used as a plasma substitute for improving microcirculation. A major side effect of HES is severe pruritus caused by HES deposits in the skin. Since specific changes are difficult to see in paraffin sections, electron microscopy is the golden standard technique in the diagnosis of HES-induced skin disease. Our aim was to compare electron microscopic search for HES deposits with other techniques.

PATIENTS AND METHODS

During the last ten years, we biopsied 21 patients suspected of having HES-induced pruritus. We compared conventional microscopy with hematoxylin & eosin and toluidine blue-stained paraffin sections, toluidine blue-stained glycide ether-embedded, semithin sections and transmission electron microscopy.

RESULTS

In 9 patients specific HES deposits could be found by evaluating toluidine blue stained semithin sections by light microscopy alone. In 6 of these cases electron microscopy was also done and confirmed the findings. In contrast, no specific findings due to HES deposits could be detected by conventional histology.

CONCLUSIONS

If specific HES deposits are found in toluidine blue-stained, glycide ether-embedded semithin sections, electron microscopy is not required.

Acquired lysosomal storage caused by frequent plasmapheresis procedures with hydroxyethyl starch

BACKGROUND

Hydroxyethyl starch (HES) solutions have largely replaced conventional plasma expanders such as human albumin and colloidal fluids. Only a few side effects have been reported and mainly concern pruritus or blood coagulation disorders. Excessive HES exposure can result in diffuse tissue storage and accumulation with foamy appearing macrophages which produce the enzyme chitotriosidase (CT). In case of massive tissue storage, this enzyme activity can reach levels comparable to those of Gaucher disease.

STUDY DESIGN AND METHODS

In this single-center retrospective analysis of 11 consecutive patients receiving large amounts of HES for chronic plasmapheresis, plasma CT activity was investigated. Five patients receiving chronic intermittent plasmapheresis with conventional plasma expanders served as controls. Plasma CT activity was measured and plotted against creatinine clearance. Where available, marrow aspirate was analyzed with light microscopy to detect foamy macrophages. One patient developed a lysosomal storage disease and was examined extensively.

RESULTS

Conventional plasma expanders did not alter plasma CT activity. In patients with impaired renal function, frequent plasma replacement with HES resulted in an increase in plasma CT activity. In the patient with the acquired lysosomal storage disease, massive tissue infiltration with activated foamy macrophages was observed. The phagocytic capacity in this patient, however, did not seem to be altered.

CONCLUSION

Patients with impaired renal function receiving large amounts of HES exhibit an increase in plasma CT activity. Because excessive HES exposure can result in an acquired lysosomal storage disease, this should be avoided in chronic plasmapheresis procedures.

Therapeutic transfusions of granulocytes collected by simple bag method for children with cancer and neutropenic infections: results of a single-centre pilot study

BACKGROUND AND OBJECTIVES

Granulocyte transfusion therapy (GTX) can be effective for life-threatening infections unresponsive to conventional antimicrobial therapies in severely neutropenic children with cancer. We developed a new granulocyte collection method, named the 'bag method', in which apheresis, hydroxyethyl starch (HES) or dexamethasone are not used. We undertook a pilot study to determine the feasibility and the safety of GTX collected by the bag method for children with cancer and life-threatening infections.

MATERIALS AND METHODS

A total of 25 GTX were administered to 13 patients (median age 3 years, range: 0.3-17; median weight 10.6 kg, range: 4.5-49.8) with neutropenia-related infections. Thirteen blood-relative donors received granulocyte colony-stimulating factor (G-CSF) (5-10 microg/kg), subcutaneously, 14 h before collection. Major end-points were granulocyte yields, post-transfusion absolute neutrophil counts (ANC) in patients, donor and patient safety, and clinical outcome on day 30.

RESULTS

The median yield of ANC per 400 ml of processed whole blood was 6.2 x 10(9) (range: 2.5-15.0 x 10(9)). Patients received a mean of 6.4 +/- 0.8 x 10(8) granulocytes per kg of body weight per transfusion. The 1-h and 24-h post-transfusion ANC rose to 607 +/- 124/microl and 704 +/- 300/microl, respectively, from the baseline of 21/microl before the first GTX. Adverse reactions were observed in five of 13 donors (bone pain, headache, vasovagal reaction; all < or = grade 2) and in two of 25 transfusions of 13 patients (transient hypoxia; grade 3). Ten patients had favourable responses, and infection resolved in nine patients.

CONCLUSIONS

The bag method without apheresis relieves the physical load of donors and enables patients with a low body weight to provide an adequate dose of granulocytes.

Hydrops lysosomalis generalisatus--an underestimated side effect of hydroxyethyl starch therapy?

Hydroxyethyl starch (HES) is usually considered to be associated with limited side effects. Generalized foamy cell macrophage syndrome after HES therapy has rarely been reported since Schaefer first described it as 'hydrops lysosomalis generalisatus' in 1982. We present a 19-yr-old male who received large amounts of HES. A bone marrow and a liver biopsy were performed because of persistent thrombocytopenia and liver dysfunction. We found severe infiltration of foamy cell degenerated macrophages in both organ systems, indicating that sequelae of HES therapy have to be included in the differential diagnosis of bone marrow and liver dysfunction.

Pruritus precipitated by hydroxyethyl starch: a review

Hydroxyethyl starch (HES) is widely used for fluid management in broad populations of patients, particularly in the surgery and intensive care settings. Pruritus, often manifested as pruritic crises, is increasingly being recognized as a common major adverse effect of HES administration. This iatrogenic form of pruritus is frequently severe and protracted with a serious negative impact on patient quality of life, including sleep disturbance, disruption of daily routine and mental distress. Such pruritus is generally refractory to available therapies and can persist for up to 12-24 months. All currently clinically available HES solutions entail the risk of pruritus, including those of diverse molecular weights and substitutions. Although dose dependent, HES-induced pruritus nevertheless can often be provoked by relatively low routine doses. The pathophysiological basis for pruritus is the widespread tissue deposition of HES, prominently in macrophages. HES tissue deposits are long lasting and sometimes massive. Usually several weeks elapse between HES exposure and the onset of pruritus. Consequently, it is important to inquire about prior HES exposure in the diagnostic evaluation of pruritus sine materia. Awareness about the scope of the pruritus problem needs to increase among physicians administering HES. Well-designed clinical outcome studies are needed to assess more fully the incidence, dose dependency and mechanisms of pruritus with particular HES solutions.

Tissue storage of 14C-labelled hydroxyethyl starch (HES) 130/0.4 and HES 200/0.5 after repeated intravenous administration to rats

OBJECTIVE

To investigate the effect of the molar substitution of hydroxyethyl starch (HES) solutions on tissue and organ storage in rats after repeated administration.

STUDY DESIGN

A controlled, multiple-dose study was performed in 48 rats. Daily bolus injections of 0.7 g/kg of 10% HES 130/0.4 or 10% HES 200/0.5 were administered on 18 consecutive days. In order to examine quantitatively the distribution and excretion of both preparations on HES tissue storage, radiolabelled HES was measured 3, 10, 24 and 52 days after the last administration. Tissue storage was expressed as percentage radioactivity of total administered HES dose in the total body, carcass, liver, kidney, spleen, lymph nodes, plasma and urine.

RESULTS

52 days after the last administration the remaining radioactivity of labelled HES 200/0.5 was nearly 4-fold higher compared with HES 130/0.4 in the total body (2.45% vs 0.65% of the total administered dose). This difference in tissue storage was statistically significant (p < or = 0.01). A comparable difference was observed for the liver and carcass.

CONCLUSION

Tissue storage after repeated administration of an HES solution with a low molar substitution (0.4) was significantly lower in the total body as well as in the liver and carcass compared with an HES solution with a medium molar substitution (0.5). However, the potential clinical consequences of these present findings have not yet been determined.

Intravenous albumin versus hydroxyethyl starch for the prevention of ovarian hyperstimulation in an in-vitro fertilization programme: a prospective randomized placebo controlled study

A prospective randomized placebo controlled clinical trial was carried out on 250 patients (cycles) considered at risk of developing OHSS in an IVF programme. Criteria for inclusion were: estradiol value of more than 3000 pg/ml or the presence of more than 20 follicles on the day of hCG administration. Patients were randomized by using a random table to receive either 20% human albumin 50 ml (n: 82); 6% hydroxyethyl starch (200/0.5) 500 ml (n: 85) or a placebo of 500 ml 0.9% NaCl solution (n: 83) over 30 min during oocyte collection. Groups were similar with respect to patients' age, estradiol levels on hCG day, body mass index, number of oocytes retrieved, number of embryos transferred and pregnancies (P>0.05). There was no severe OHSS in patients who received albumin and HES while four patients who received placebo developed severe OHSS. On the other hand moderate OHSS was encountered in four patients in the albumin group; five patients receiving HES; and 12 patients receiving placebo. There was a statistically significant difference in the incidence of moderate, severe and overall OHSS among groups (P values of <0.05, <0.05, and <0.01, respectively). Both HES and albumin significantly reduced the incidence of moderate, severe and overall incidence of OHSS. It is concluded that hydroxyethyl starch is a cheaper and safer alternative to Human Albumin in OHSS prevention.

The incidence of hydroxyethyl starch-associated pruritus

BACKGROUND

Pruritus due to hydroxyethyl starch (HES) is reported with a very variable frequency but appears to be relatively uncommon in the U.K. compared with other European countries.

OBJECTIVES

To determine the frequency of HES-related pruritus in patients discharged from intensive care units (ICUs) in two U.K. hospitals.

METHODS

A questionnaire survey was given to 253 patients after discharge from ICU. Questions were designed to exclude pre-existing skin disease and other causes of pruritus.

RESULTS

One hundred and fifty-nine completed questionnaires were suitable for analysis. Seventeen of 135 (12.6%) subjects who had received HES reported itch, as did one of 24 who had not received HES. There was no apparent relationship between the occurrence of HES-related pruritus and either the surgical indication or the brand or volume of HES infused.

CONCLUSIONS

HES-related pruritus is a problem that dermatologists need to recognize; however, its frequency in the U.K., when other causes of itch are excluded, appears to be lower than suggested in some previous reported studies.

Giving long-persistent starch as volume replacement can cause pruritus after cardiac surgery

We reviewed the prevalence and severity of pruritus in 85 patients after cardiac surgery. EloHAES, a long-lasting hydroxyethylated starch, was given to 59 of these patients. None of the patients who did not receive EloHAES developed pruritus, compared with 22% of those who did (P = 0.007). The timing of onset, duration and severity of the pruritus are similar to those found previously for other hydroxyethylated starches, and the cause of this pruritus is likely to be similar. Hydroxyethyl starch can cause long-term pruritus.

Partial colloid starch replacement for therapeutic plasma exchange

Traditionally protein solutions have been used as the replacement solution of choice during therapeutic plasma exchange (TPE). Treatment protocols vary, but neurology patients, who exhibit autonomic instability, are typically replaced entirely with 5% protein solution. Due to sporadic product shortages and the increasing cost of protein solutions, we evaluated the use of 6% and 3% hetastarch (HES) as partial replacement during TPE. All adult neurology patients with normal liver, heart, and kidney function were evaluated for HES replacement. The first seven patients (33 procedures) received 1000 ml of 6% hetastarch as part of their replacement fluid and the next 42 patients (289 procedures) received 1000 ml of 3% HES as part of their replacement fluid. Three patients crossed over into both groups. Patients were evaluated for signs of peripheral edema, evidence of bleeding, skin rash, and any subjective changes. Total protein albumin, osmolality, PT, and aPTT were measured prior to each procedure in the first five patients in each group. In both groups there was a drop in total protein, but all other lab values returned to normal limits within 48 hours of treatment. One patient reported slight peripheral edema after two procedures. In the 3% HES group the BP and P remained stable in 97.3% (280) procedures. Two patients receiving 6% HES and 1 patient receiving 3% HES complained of severe transient back and head pain during HES infusion. There was no evidence of bleeding or subjective changes. Three percent HES is a safe and cost-effective partial replacement for albumin during TPE.

Alternatives to albumin: starch replacement for plasma exchange

Today, albumin, or a combination of saline and albumin, is used and widely accepted as a replacement for routine plasma exchange. However, decreased availability (due to market recalls secondary to Creutzfeld-Jacob or bacterial contamination risk) rising costs, recognition of drug interactions with albumin (i.e., ACE inhibitors) and a fear of disease transmission have led several groups to reconsider the use of colloid starches as partial or full replacement for plasma during plasma exchange. There are two hydroxyethyl starches: hetastarch (Hespan and Pentaspan) currently licensed for human use in the United States. While both are approved for granulocyte collection only Hespan is approved as a plasma volume expander. Anecdotal experience and limited reports in the literature with the use of starches as a replacement for plasma exchange suggest that such starch products are a reasonable replacement for albumin as an initial wash-out fluid or in combination with either albumin or saline. Kinetic modeling of the wash-out of starch used as a replacement fluid demonstrate that relatively little residual starch remains compared to the total amount infused. Hydroxyethyl starches are biochemically similar to glycogen, which likely explains the lack of immunogenicity and lack of adverse reactions. Substantial cost savings are associated with the substitution of starch for albumin. It is concluded that HES is well-tolerated and cost-effective as full or partial volume replacement with plasma exchange. It is anticipated that the use of HES will emerge as a standard of care in apheresis.

Assessment of the safety and tolerance of 6% hydroxyethyl starch (200/0.5) solution: a randomized, controlled epidemiology study

None of the natural and synthetic colloids currently available is free from the risk of side effects. This study was performed to contribute to the epidemiology of adverse reactions of the widely used 200/0.5 hydroxyethyl starch 6% solution (HES). Study end points were anaphylactoid reactions during preanesthesia infusion and perioperative course, and pruritus 5 days postoperatively (clinical examination and inquiry) and 8 wk after application (mailed patient questionnaire). We consecutively randomized 750 patients undergoing minor elective surgery into two parallel groups treated with HES (from two different manufacturers) and one control group treated with lactated Ringer's solution. The study population was well matched among the groups and consisted of patients of both sexes, aged 18-95 yr, ASA physical status I-III. No drug-related anaphylactoid reactions were detected during either of the observation intervals. There was no episode of pruritus after the fifth postoperative day. Incidence of pruritus after 8 wk was quite frequent but not significantly different (chi2 test, P = 0.77): 9.1% and 12.0% in the two HES groups and 11.5% in the lactated Ringer's solution control group. Except for pruritus, we conclude that HES was associated with no more complications than lactated Ringer's solution.

IMPLICATIONS

Anaphylactoid reactions and pruritus (itching) after the administration of a 6% hydroxyethyl starch (200/0.5) versus lactated Ringer's solution were assessed in a prospective, randomized, controlled study. There were no differences, although there was a more than 10% incidence of pruritus in both groups.

Decreased activity of acid alpha-glucosidase in a patient with persistent periocular swelling after infusions of hydroxyethyl starch

After infusion therapy with hydroxyethyl starch (HES) on account of sudden hearing loss, a 68-year-old woman developed a marked and persistent periocular swelling. This extraordinary adverse effect caused us to search for an explanation by means of histopathology, immunohistochemistry, immunoelectron microscopy and biochemistry. In lesional periocular skin and in normal-appearing skin, lysosomal storage of HES could be detected with a specific HES antibody in histiocytes, endothelial cells, basal keratinocytes and small nerves. In the periocular skin, a stronger deposition of HES was found in addition to distinct xanthomatous changes as well as features of lymphoedema. In view of lysosomal HES storage we measured the pH-dependent activity of the lysosomal alpha-glucosidase (GAA) in cultured fibroblasts. We found a 50% decreased activity of the acid GAA, which is consistent with a heterozygous state of glycogenosis type II (Pompe's disease) and potentially of pathogenetic relevance for the intralysosomal accumulation of HES. Xanthomatous changes and lymphoedema are likely to be secondary effects, but contribute considerably to the clinical manifestation of persistent visible swelling. This observation could point to a role for GAA in the elimination of tissue-stored HES. Patients with decreased activities of GAA may be at risk of unusual adverse effects following extraordinary and prolonged tissue storage of HES, especially if it is infused in large quantities.

The pharmacokinetics of acetyl starch as a plasma volume expander in patients undergoing elective surgery

Acetyl starch (ACS) is a new synthetic colloid solution for plasma volume expansion and is now undergoing phase 2 clinical trials. We compared the pharmacokinetics of ACS with those of hydroxyethyl starch (HES) in 32 patients (ASA physical status I and II) undergoing elective surgery. In this randomized, double-blind trial, patients received either 15 mL/kg ACS 6% (average molecular weight [Mw] 200,000/molar substitution [MS] 0.5) or HES 6% (Mw 200,000/MS 0.5) i.v. up to a maximal dose of 1000 mL. Plasma colloid concentrations were measured by repetitive arterial blood sampling over 24.5 h. Plasma colloid concentrations were detected using a high-pressure liquid chromatography controlled enzymatic test. Standard pharmacokinetics were calculated, including initial half-life (t(1/2init)), i.e., the time required for a 50% decline of the maximal plasma colloid concentration at the end of drug infusion. Whereas HES was eliminated by second-order kinetics, ACS followed first-order characteristics. In the first hours after i.v. administration, t(1/2init) and clearances were similar in both groups. However, the terminal half-life of HES was significantly longer than that of ACS (9.29 +/- 1.43 h vs 4.37 +/- 1.06 h). After 16.5 and 24.5 h, ACS showed significantly lower plasma concentrations than HES, which indicates that the final degradation of ACS by esterases and amylase was significantly more rapid. ACS might be an alternative plasma volume expander, which avoids the accumulation of persisting macromolecules.

IMPLICATIONS

We studied the pharmacokinetics of acetyl starch, a newly developed colloid solution for plasma volume substitution, compared with hydroxyethyl starch in 32 surgical patients undergoing elective major general surgical procedures. In contrast to hydroxyethyl starch, this new agent undergoes rapid and nearly complete enzymatic degradation.

Washout kinetics of colloidal starch as a partial or full replacement for plasma exchange

Colloidal starch has been used safely as a plasma expander and an erythrocyte sedimenting agent for over 25 years. However, there remains some concern in regard to the long term sequelae of the administration of large volumes of colloid starch such as would be administered if colloidal starch were used as a plasma replacement during serial plasma exchanges. We identified mathematical relations that allowed for the calculations of the theoretical circulating residual starch in a patient undergoing serial plasma exchanges and used it to model a variety of possible clinical scenarios. Following six one plasma volume exchanges, one would expect only 11, 13, 14, or 17% of the total infused starch to be remaining in the circulation. For example, in the case of a 4L exchange with full replacement, only the starch in 4.1 liters (4L x 6 exchanges x 17% = 4.1L) would be expected to remain in the circulation despite an infusion of 24 L (4L x 6 exchanges = 24L) of starch. The results suggest that relatively small amounts of starch would be expected to remain circulating relative to the large amounts infused following a series of plasma exchanges with partial or full starch replacement.

Efficacy of pentastarch in granulocyte collection by centrifugal leukapheresis

The efficacy of 6% hydroxyethyl starch (hetastarch, HS) in enhancing granulocyte harvest by centrifugal leukapheresis has been described by a simple equation which predicts the granulocyte collection efficiency (GCE) based on an intrinsic donor variable, the erythrocyte sedimentation rate (ESR): GCE(%) = 1.3 ESR (mm/hr) + 45. Ten percent low molecular weight hydroxyethyl starch (pentastarch, PS) has been reported to be as effective as HS with potentially fewer adverse donor reactions (ADR). The derivation of an analogous equation for PS under conditions previously reported for HS may quantify PS efficacy and allow comparison to HS. We prospectively measured the in vitro and the in vivo effects of PS on the donor ESR in 53 granulocyte collections from 44 donors using the model CS-3000 Plus blood cell separator (CS). We then correlated the findings with the GCE of each procedure and derived an equation which expresses GCE in terms of baseline donor ESR. The in vitro addition of PS increased the donor ESR 2.4-fold, but its administration to a donor during a collection procedure did not appreciably change the ESR. Higher baseline donor ESR was more likely to result in more efficient cell collections: GCE (%) = 0.8 ESR (mm/hr) + 20; (r = 0.37). For granulocyte harvests using the CS and PS as the sedimenting agent 1) baseline donor ESR affects granulocyte harvests, but the poor correlation does not allow an accurate prediction of GCE and cell yield from the baseline donor ESR; 2) in comparison with HS (results from a previous study), PS may be less effective in vitro and not effective in vivo in elevating ESR, and may be less effective in enhancing granulocyte harvest; and 3) the parameters (slope, y-intercept, correlation coefficient) which define the linear relationship between baseline donor ESR and GCE may serve collectively as a quantitative measure of the effectiveness of different hydroxyethyl starch agents in enhancing granulocyte harvests. These parameters may be helpful in rapidly assessing the clinical efficacy of new, potentially useful hydroxyethyl starch agents prior to initiating a randomized, controlled clinical trial.

Successful treatment of hydroxyethyl starch-induced pruritus with topical capsaicin

We report a case of recalcitrant pruritus after infusion therapy with hydroxyethyl starch (HES) for sudden deafness. The diagnosis was confirmed by detection of typical HES storage vacuoles within dermal macrophages and perineural cells. Treatment with antihistamines and antipruritic agents, UVB irradiation, and neuroleptic drugs, was ineffective. Topical capsaicin (0.05%) twice daily produced excellent symptomatic relief, without side-effects.

Human monocytes and keratinocytes in culture ingest hydroxyethylstarch

Severe itching for unknown reasons has been reported after administration of hydroxyethylstarch (HES) in haemodilution therapy of humans. In skin sections from patients who had received HES for otological reasons HES deposition was found by immunohistochemical methods in keratinocytes, epidermal dendritic cells, endothelial cells and macrophages. The aim of the present investigation was to study the interaction of cultured human monocytes and keratinocytes, normal (HNK) and malignant (KB, A431), with FITC-conjugated HES (200/0.5). Peripheral blood monocytes from healthy donors were isolated by Ficoll-Hypaque gradient centrifugation and adherence to plastic surfaces. Cells were incubated with HES-FITC (1 mg/ml) for 10, 20, 30, 60 and 120 min at 37 degrees C, washed several times to minimize cell-associated HES-FITC. The uptake of HES-FITC (200/0.5) was detected by fluorescence microscopy and flow cytometry. Monocytes and keratinocytes (HNK, KB, A431) acquired significant amounts of HES-FITC after 120 min. Endocytosis was blunted by the addition of unconjugated HES in ten-fold concentration. At 4 degrees C, a further inhibition was achieved, indicating an uptake of HES-FITC by monocytes and keratinocytes in vitro. These results indicate that a connection between the storage of HES by keratinocytes and monocytes and the observed itching in patients might be possible.