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

Quality of life and pruritus in patients with severe sepsis resuscitated with hydroxyethyl starch long-term follow-up of a randomised trial

INTRODUCTION

The effects of hydroxyethyl starch (HES) on patient-centered outcome measures have not been fully described in patients with severe sepsis. We assessed health-related quality of life (HRQoL) and the occurrence of pruritus in patients with severe sepsis randomized to resuscitation with HES 130/0.42 or Ringer's acetate.

METHODS

We did post hoc analyses of the Danish survivors (n=295) of the 6S trial using mailed questionnaires on self-perceived HRQoL (Short Form (SF) - 36) and pruritus.

RESULTS

Median 14 months (interquartile range 10 to 18) after randomization, 182 (61%) and 185 (62%) completed questionnaires were obtained for the assessment of HRQoL and pruritus, respectively. Responders were older than nonresponders, but characteristics at randomization of the responders in the HES vs. Ringer's groups were comparable. At follow-up, the patients in the HES group had lower mental component summary scores than those in the Ringer's group (median 45 (interquartile range 36 to 55) vs. 53 (39 to 60), P=0.01). The group differences were mainly in the scales of vitality and mental health. There was no difference in the physical component summary scores between groups, but patients in the HES group scored worse in bodily pain. Forty-nine percent of patients allocated to HES had experienced pruritus at any time after ICU discharge compared to 43% of those allocated to Ringer's (relative risk 1.13, 95% confidence interval 0.83 to 1.55, P=0.43).

CONCLUSIONS

At long-term follow-up patients with severe sepsis assigned to resuscitation with HES 130/0.42 had worse self-perceived HRQoL than those assigned to Ringer's acetate whereas there were no statistically significant differences in the occurrence of pruritus.

Basics of fluid and blood transfusion therapy in paediatric surgical patients

Perioperative fluid, electrolyte and blood transfusion therapy for infants and children can be confusing due the numerous opinions, formulas and clinical applications, which can result in a picture that is not practical and is often misleading. Perioperatively, crystalloids, colloids and blood components are required to meet the ongoing losses and for maintaining cardiovascular stability to sustain adequate tissue perfusion. Recently controversies have been raised regarding historically used formulas and practices of glucose containing hypotonic maintenance crystalloid solutions for perioperative fluid therapy in children. Paediatric intraoperative transfusion therapy, particularly the approach to massive blood transfusion (blood loss ≥ one blood volume) can be quite complex because of the unique relationship between the patient's blood volume and the volume of the individual blood product transfused. A meticulous fluid, electrolyte and blood transfusion management is required in paediatric patients perioperatively because of an extremely limited margin for error. This article reviews the basic concepts in perioperative fluid and blood transfusion therapy for paediatric patients, along with recent recommendations. For this review, Pubmed, Ovid MEDLINE, HINARI and Google scholar were searched without date restrictions. Search terms included the following in various combinations: Perioperative, fluid therapy, paediatrics, blood transfusion, electrolyte disturbances and guidelines. Only articles with English translation were used.

Perioperative crystalloid and colloid fluid management in children: where are we and how did we get here?

It has been more than 50 yr since the landmark article in which Holliday and Segar (Pediatrics 1957;19:823-32) proposed the rate and composition of parenteral maintenance fluids for hospitalized children. Much of our practice of fluid administration in the perioperative period is based on this article. The glucose, electrolyte, and intravascular volume requirements of the pediatric surgical patient may be quite different than the original population described, and consequently, use of traditional hypotonic fluids proposed by Holliday and Segar may cause complications, such as hyperglycemia and hyponatremia, in the postoperative surgical patient. There is significant controversy regarding the choice of isotonic versus hypotonic fluids in the postoperative period. We discuss the origins of perioperative fluid management in children, review the current options for crystalloid fluid management, and present information on colloid use in pediatric patients.

Hydroxyethyl starch enhances argatroban-mediated decreases in clot propagation and strength by diminishing thrombin–fibrinogen interactions

Direct thrombin inhibitors (DTIs) have been administered for anticoagulation during cardiopulmonary bypass for patients with heparin-induced thrombocytopenia. While DTIs prolonged clot initiation and decreased clot propagation, clot strength did not change. Hydroxyethyl starches (HES), however, significantly decreased clot propagation and strength. We hypothesized that DTI with HES could significantly decrease hemostasis more than DTI alone. Plasma was exposed to 0 or 5 microg/ml argatroban with 0 or 30% dilution with 0.9% NaCl, 10% pentastarch or 6% Voluven. Additional argatroban-exposed samples diluted with HES had addition of alpha-thrombin (0.25 U/ml) and fibrinogen (150 mg/ml). Clot kinetics were determined via thrombelastography. While dilution with 0.9% NaCl significantly (P < 0.05) decreased the clot strength by 17% compared with samples only exposed to argatroban, dilution with pentastarch and Voluven significantly (P < 0.05) markedly decreased clot strength (53 and 78%, respectively). Voluven dilution significantly increased the time to clot initiation and decreased the velocity of clot propagation compared with samples only exposed to argatroban. Addition of alpha-thrombin/fibrinogen restored clot strength. DTI/HES administration diminished hemostasis to a greater extent than DTI exposure alone. Further investigation is warranted to determine whether this therapeutic approach can improve the safety of anticoagulation during cardiopulmonary bypass in patients with heparin-induced thrombocytopenia.

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.

New Light on Intravascular Volume Replacement Regimens: What Did We Learn from the Past Three Years?

Definition of the "ideal" intravascular fluid volume replacement strategy still remains a critical problem. This article analyzes studies on volume replacement by using a MEDLINE search of the past 3 years (from January 1, 2000, to December 12, 2002). Forty original studies in humans with a total of 2454 subjects were identified. Five studies were performed in volunteers (n = 113); the other 35 studies (n = 2341) were performed in a variety of patients (e.g., cardiac surgery, trauma patients, children, and intensive care unit patients). The influence of different volume replacement regimens on coagulation was one of the major topics of interest (16 studies with 1183 subjects), and other studies focused on metabolic state, alterations in macro- and microcirculation, volume distribution, and organ function (e.g., kidney function and splanchnic perfusion). Among all synthetic colloids, hydroxyethyl starch (HES) was the solution most often studied. Two new HES preparations have been approved (Hextend), a balanced hetastarch solution, and a new third-generation HES [130/0.4]). Only two studies used albumin, and no superiority of albumin was found over less expensive synthetic colloids. In almost all studies, the outcome either was no end-point or was not reported. Volume replacement has often been hitherto based on dogma and personal beliefs. Future well performed studies in this area will hopefully help to shed new light on the ideal volume replacement strategy.

IMPLICATIONS

By using a MEDLINE search covering the last 3 yr, the present knowledge on volume replacement regimens was analyzed. Forty studies in humans were identified. New hydroxyethyl starch preparations have shed light on this topic, whereas no additional data supporting the use of albumin have been presented.

A randomized, controlled study of fluid management in infants and toddlers during surgery: hydroxyethyl starch 6% (HES 70/0.5) vs lactated Ringer's solution

BACKGROUND

Volume replacement with hydroxyethyl starch (HES), a synthetic colloid, is widely accepted in adults, but only few data exist regarding its use in children. The aim of this study was to assess the effect of a low molecular weight HES solution (HES 70/0.5) compared with lactated Ringer's solution (LR) on haemoglobin levels as an indirect measure of plasma expansion in infants and toddlers, and its perioperative safety.

METHODS

Sixty-four patients, aged 1-38 months, were allocated randomly to receive 20 ml x kg-1 body weight of either HES 70/0.5 or LR during the first hour of urological surgery lasting >2 h. Thereafter, only LR was infused to maintain haemodynamic stability. Intraoperative blood loss and administered fluid volumes were analysed. Haemoglobin levels were determined perioperatively and intraoperatively at completion of volume loading. Changes in body weight and the incidence of postoperative oedema were assessed 24 and 48 h after surgery. For the safety analysis, patients were monitored for 72 h.

RESULTS

Intraoperative haemoglobin levels decreased significantly more with HES 70/0.5 (30 +/- 10 g.l-1) compared with LR (21 +/- 12 g.l-1) (P < 0.01). The overall administered fluid volumes during surgery did not differ between groups. The postoperative changes in body weight and incidence of postoperative oedema did not differ between groups. No anaphylactoid reactions, pruritus or adverse effects were observed during the study period.

CONCLUSIONS

A larger decrease in haemoglobin levels in infants and toddlers after HES 70/0.5 (20 ml.kg-1) compared with LR indicates a more effective plasma expansion. HES might be considered as a volume expander in the paediatric population.

Evaluation of a new hydroxyethyl starch solution (HES 130/0.4) in patients undergoing preoperative autologous blood donation

STUDY OBJECTIVE

To compare the tolerance and efficacy of the new hydroxyethyl starch (HES) 130/0.4 with a current HES solution (HES 200/0.5) in patients undergoing preoperative autologous blood donation as a model of surgical blood loss. HES 130/0.4 is expected to be a plasma substitute as efficacious as current HES solutions while offering such advantages as more complete renal elimination and reduced tissue storage.

DESIGN

Controlled, randomized, double-blind, phase II clinical trial.

SETTING

1500-bed university hospital.

PATIENTS

60 ASA physical status II and III patients scheduled for elective cardiac and noncardiac surgery, and meeting selection criteria for autologous blood donors.

INTERVENTIONS

Collection of 500 mL of blood with simultaneous intravenous (IV) infusion of 500 mL of either HES 130/0.4 or HES 200/0.5 (mean molecular weight 130 kD and 200 kD, degree of substitution 0.4 and 0.5, respectively).

MEASUREMENTS

Noninvasive measurements of heart rate and arterial blood pressure were obtained every 5 minutes until 1 hour after blood donation and infusion of the study drugs; laboratory studies (complete blood counts, electrolytes, markers of renal and liver function) were performed; and follow-up assessment of adverse events was undertaken by questionnaire 24 hours after blood donation and infusion of the study drugs.

MAIN RESULTS

Both hemodynamics and laboratory test results did not differ significantly between the groups at any time. Hemodynamics remained stable in each group, and no adverse event was observed in any patient until one hour after blood donation and infusion of the study drugs. Adverse events elicited by postphlebotomy questionnaire were mild and probably unrelated to HES infusion.

CONCLUSIONS

Intravenous infusion of 500 mL of the new HES 130/0.4 was tolerated well and maintained cardiovascular stability in patients undergoing preoperative autologous blood donation. HES 130/0.4 proved equivalent to HES 200/0.5 in every measured respect. Its pharmacokinetic profile may render HES 130/0.4 an attractive alternative to current HES solutions.