Safety and efficacy of tetrastarches in surgery and trauma: a systematic review and meta-analysis of randomised controlled trials

BACKGROUND

Hydroxyethyl starch (HES) 130 is a frequently used fluid to replace intravascular losses during surgery or trauma. In the past years, several trials performed in critically ill patients have raised questions regarding the safety of this product. Our aim in this meta-analysis was to evaluate the safety and efficacy of 6% HES during surgery and in trauma.

METHODS

This systematic review and meta-analysis was registered at PROSPERO (CRD42018100379). We included 85 fully published articles from 1980 to June 2018 according to the protocol and three additional recent articles up to June 2020 in English, French, German, and Spanish reporting on prospective, randomised, and controlled clinical trials applying volume therapy with HES 130/0.4 or HES 130/0.42, including combinations with crystalloids, to patients undergoing surgery. Comparators were albumin, gelatin, and crystalloids only. A meta-analysis could not be performed for the two trauma studies as there was only one study that reported data on endpoints of interest.

RESULTS

Surgical patients treated with HES had lower postoperative serum creatinine (P<0.001) and showed no differences in renal dysfunction, renal failure, or renal replacement therapy. Although there was practically no further difference in the colloids albumin or gelatin, the use of HES improved haemodynamic stability, reduced need for vasopressors (P<0.001), and decreased length of hospital stay (P<0.001) compared with the use of crystalloids alone.

CONCLUSIONS

HES was shown to be safe and efficacious in the perioperative setting. Results of the present meta-analysis suggest that when used with adequate indication, a combination of intravenous fluid therapy with crystalloids and volume replacement with HES as colloid has clinically beneficial effects over using crystalloids only.

Colloids versus crystalloids for fluid resuscitation in critically ill people

BACKGROUND

Critically ill people may lose fluid because of serious conditions, infections (e.g. sepsis), trauma, or burns, and need additional fluids urgently to prevent dehydration or kidney failure. Colloid or crystalloid solutions may be used for this purpose. Crystalloids have small molecules, are cheap, easy to use, and provide immediate fluid resuscitation, but may increase oedema. Colloids have larger molecules, cost more, and may provide swifter volume expansion in the intravascular space, but may induce allergic reactions, blood clotting disorders, and kidney failure. This is an update of a Cochrane Review last published in 2013.

OBJECTIVES

To assess the effect of using colloids versus crystalloids in critically ill people requiring fluid volume replacement on mortality, need for blood transfusion or renal replacement therapy (RRT), and adverse events (specifically: allergic reactions, itching, rashes).

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase and two other databases on 23 February 2018. We also searched clinical trials registers.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) and quasi-RCTs of critically ill people who required fluid volume replacement in hospital or emergency out-of-hospital settings. Participants had trauma, burns, or medical conditions such as sepsis. We excluded neonates, elective surgery and caesarean section. We compared a colloid (suspended in any crystalloid solution) versus a crystalloid (isotonic or hypertonic).

DATA COLLECTION AND ANALYSIS

Independently, two review authors assessed studies for inclusion, extracted data, assessed risk of bias, and synthesised findings. We assessed the certainty of evidence with GRADE.

MAIN RESULTS

We included 69 studies (65 RCTs, 4 quasi-RCTs) with 30,020 participants. Twenty-eight studied starch solutions, 20 dextrans, seven gelatins, and 22 albumin or fresh frozen plasma (FFP); each type of colloid was compared to crystalloids.Participants had a range of conditions typical of critical illness. Ten studies were in out-of-hospital settings. We noted risk of selection bias in some studies, and, as most studies were not prospectively registered, risk of selective outcome reporting. Fourteen studies included participants in the crystalloid group who received or may have received colloids, which might have influenced results.We compared four types of colloid (i.e. starches; dextrans; gelatins; and albumin or FFP) versus crystalloids.Starches versus crystalloidsWe found moderate-certainty evidence that there is probably little or no difference between using starches or crystalloids in mortality at: end of follow-up (risk ratio (RR) 0.97, 95% confidence interval (CI) 0.86 to 1.09; 11,177 participants; 24 studies); within 90 days (RR 1.01, 95% CI 0.90 to 1.14; 10,415 participants; 15 studies); or within 30 days (RR 0.99, 95% CI 0.90 to 1.09; 10,135 participants; 11 studies).We found moderate-certainty evidence that starches probably slightly increase the need for blood transfusion (RR 1.19, 95% CI 1.02 to 1.39; 1917 participants; 8 studies), and RRT (RR 1.30, 95% CI 1.14 to 1.48; 8527 participants; 9 studies). Very low-certainty evidence means we are uncertain whether either fluid affected adverse events: we found little or no difference in allergic reactions (RR 2.59, 95% CI 0.27 to 24.91; 7757 participants; 3 studies), fewer incidences of itching with crystalloids (RR 1.38, 95% CI 1.05 to 1.82; 6946 participants; 2 studies), and fewer incidences of rashes with crystalloids (RR 1.61, 95% CI 0.90 to 2.89; 7007 participants; 2 studies).Dextrans versus crystalloidsWe found moderate-certainty evidence that there is probably little or no difference between using dextrans or crystalloids in mortality at: end of follow-up (RR 0.99, 95% CI 0.88 to 1.11; 4736 participants; 19 studies); or within 90 days or 30 days (RR 0.99, 95% CI 0.87 to 1.12; 3353 participants; 10 studies). We are uncertain whether dextrans or crystalloids reduce the need for blood transfusion, as we found little or no difference in blood transfusions (RR 0.92, 95% CI 0.77 to 1.10; 1272 participants, 3 studies; very low-certainty evidence). We found little or no difference in allergic reactions (RR 6.00, 95% CI 0.25 to 144.93; 739 participants; 4 studies; very low-certainty evidence). No studies measured RRT.Gelatins versus crystalloidsWe found low-certainty evidence that there may be little or no difference between gelatins or crystalloids in mortality: at end of follow-up (RR 0.89, 95% CI 0.74 to 1.08; 1698 participants; 6 studies); within 90 days (RR 0.89, 95% CI 0.73 to 1.09; 1388 participants; 1 study); or within 30 days (RR 0.92, 95% CI 0.74 to 1.16; 1388 participants; 1 study). Evidence for blood transfusion was very low certainty (3 studies), with a low event rate or data not reported by intervention. Data for RRT were not reported separately for gelatins (1 study). We found little or no difference between groups in allergic reactions (very low-certainty evidence).Albumin or FFP versus crystalloidsWe found moderate-certainty evidence that there is probably little or no difference between using albumin or FFP or using crystalloids in mortality at: end of follow-up (RR 0.98, 95% CI 0.92 to 1.06; 13,047 participants; 20 studies); within 90 days (RR 0.98, 95% CI 0.92 to 1.04; 12,492 participants; 10 studies); or within 30 days (RR 0.99, 95% CI 0.93 to 1.06; 12,506 participants; 10 studies). We are uncertain whether either fluid type reduces need for blood transfusion (RR 1.31, 95% CI 0.95 to 1.80; 290 participants; 3 studies; very low-certainty evidence). Using albumin or FFP versus crystalloids may make little or no difference to the need for RRT (RR 1.11, 95% CI 0.96 to 1.27; 3028 participants; 2 studies; very low-certainty evidence), or in allergic reactions (RR 0.75, 95% CI 0.17 to 3.33; 2097 participants, 1 study; very low-certainty evidence).

AUTHORS' CONCLUSIONS

Using starches, dextrans, albumin or FFP (moderate-certainty evidence), or gelatins (low-certainty evidence), versus crystalloids probably makes little or no difference to mortality. Starches probably slightly increase the need for blood transfusion and RRT (moderate-certainty evidence), and albumin or FFP may make little or no difference to the need for renal replacement therapy (low-certainty evidence). Evidence for blood transfusions for dextrans, and albumin or FFP, is uncertain. Similarly, evidence for adverse events is uncertain. Certainty of evidence may improve with inclusion of three ongoing studies and seven studies awaiting classification, in future updates.

Parenteral fluid regimens for improving functional outcome in people with acute stroke

BACKGROUND

Parenteral fluids are commonly used in people with acute stroke with poor oral fluid intake. However, the balance between benefit and harm for different fluid regimens is unclear.

OBJECTIVES

To assess whether different parenteral fluid regimens lead to differences in death, or death or dependence, after stroke based on fluid type, fluid volume, duration of fluid administration, and mode of delivery.

SEARCH METHODS

We searched the Cochrane Stroke Group Trials Register (May 2015), the Cochrane Central Register of Controlled Trials (CENTRAL), the Cochrane Database of Systematic Reviews (CDSR) and the Database of Abstracts of Reviews of Effects (DARE) (Cochrane Library 2015, Issue 5), MEDLINE (2008 to May 2015), EMBASE (2008 to May 2015), and CINAHL (1982 to May 2015). We also searched ongoing trials registers (May 2015) and reference lists, performed cited reference searches, and contacted authors.

SELECTION CRITERIA

Randomised trials of parenteral fluid regimens in adults with ischaemic or haemorrhagic stroke within seven days of stroke onset that reported death or dependence.

DATA COLLECTION AND ANALYSIS

One review author screened titles and abstracts. We obtained the full-text articles of relevant studies, and two review authors independently selected trials for inclusion and extracted data. We used Cochrane's tool for bias assessment.

MAIN RESULTS

We included 12 studies (2351 participants: range 27 to 841).Characteristics: The 12 included studies compared hypertonic (colloids) with isotonic fluids (crystalloids); of these, five studies (1420 participants) also compared 0.9% saline with another fluid. No data were available to make other comparisons. Delay from stroke to recruitment varied from less than 24 hours to 72 hours. Duration of fluid delivery was between two hours and 10 days.Bias assessment: Investigators and participants in eight of the 12 included studies were blind to treatment allocation, seven of the 12 included studies gave details of randomisation, and eight of the 12 included studies reported all outcomes measured.

RESULTS

There were no relevant completed trials that addressed the effect of volume, duration, or mode of fluid delivery on death or dependence in people with stroke.The odds of death or dependence were similar in participants allocated to colloids or crystalloid fluid regimens (odds ratio (OR) 0.97, 95% confidence interval (CI) 0.79 to 1.21, five studies, I² = 58%, low-quality evidence), and between 0.9% saline or other fluid regimens (OR 1.04, 95% CI 0.82 to 1.32, three studies, I² = 71%, low-quality evidence). There was substantial heterogeneity in these estimates.The odds of death were similar between colloids and crystalloids (OR 1.02, 95% CI 0.82 to 1.27, 12 studies, I² = 24%, moderate-quality evidence), and 0.9% saline and other fluids (OR 0.87, 95% CI 0.67 to 1.12, five studies, I² = 53%, low-quality evidence). The odds of pulmonary oedema were higher in participants allocated to colloids (OR 2.34, 95% CI 1.28 to 4.29, I² = 0%). Although the studies observed a higher risk of cerebral oedema (OR 0.20, 95% CI 0.02 to 1.74) and pneumonia (OR 0.58, 95% CI 0.17 to 2.01) with crystalloids, we could not exclude clinically important benefits or harms.

AUTHORS' CONCLUSIONS

We found no evidence that colloids were associated with lower odds of death or dependence in the medium term after stroke compared with crystalloids, though colloids were associated with greater odds of pulmonary oedema. We found no evidence to guide the best volume, duration, or mode of parenteral fluid delivery for people with acute stroke.

Colloids versus crystalloids in objective-guided fluid therapy, systematic review and meta-analysis. Too early or too late to draw conclusions

INTRODUCTION

Several clinical trials on Goal directed fluid therapy (GDFT) were carried out, many of those using colloids in order to optimize the preload. After the decision of European Medicines Agency, there is such controversy regarding its use, benefits, and possible contribution to renal failure. The objective of this systematic review and meta-analysis is to compare the use of last-generation colloids, derived from corn, with crystalloids in GDFT to determine associated complications and mortality.

METHODS

A bibliographic research was carried out in MEDLINE PubMed, EMBASE and Cochrane Library, corroborating randomized clinical trials where crystalloids are compared to colloids in GDFT for major non-cardiac surgery in adults.

RESULTS

One hundred thirty references were found and among those 38 were selected and 29 analyzed; of these, six were included for systematic review and meta-analysis, including 390 patients. It was observed that the use of colloids is not associated with the increase of complications, but rather with a tendency to a higher mortality (RR [95% CI] 3.87 [1.121-13.38]; I(2)=0.0%; p=0.635).

CONCLUSIONS

Because of the limitations of this meta-analysis due to the small number of randomized clinical trials and patients included, the results should be taken cautiously, and the performance of new randomized clinical trials is proposed, with enough statistical power, comparing balanced and unbalanced colloids to balanced and unbalanced crystalloids, following the protocols of GDFT, considering current guidelines and suggestions made by groups of experts.

CRYSTALLOID PRELOAD SHOWS TRANSIENT SUPERIORITY OVER COLLOID, OR THEIR COMBINATION IN SPINAL ANAESTHESIA-INDUCED HYPOTENSION PROPHYLAXIS FOR CAESAREAN SECTION

BACKGROUND

Many studies comparing different intravenous fluid types usually do not use equipotent volumes of 3:1 crystalloid: colloid ratio in such comparisons. Conflicting results emanate from such studies. This study was designed to compare the efficacy of equipotent volumes of crystalloid, colloid and combination of crystalloid/colloid in spinal anaesthesia-induced hypotension prophylaxis.

METHODOLOGY

Pregnant women scheduled for elective Caesarean section were prospectively randomized to three groups to each received either 1 500 ml of Ringers lactate, or 500 ml of 6% pentastarch or a combination of 250 ml of 6% pentastarch and 750 ml of Ringers lactate intravenous fluid preload, before spinal anaesthesia. Hemodynamic variables were monitored.

RESULTS

First 10 minutes, crystalloid showed better efficacy in hypotension prophylaxis over the other regimen. In the next 30 minutes however, there were no significant differences between the groups.

CONCLUSION

Crystalloids proved more effective than colloid or their combination in hypotension prophylaxis in the first 10 minutes after spinal anaesthesia.

[The role of colloids in intensive care medicine. Evidence instead of emotions]

BACKGROUND

Besides albumin, which is gained from human donors, synthetic colloids have been playing a dominant role in treating patients in shock and are standard therapy in intensive care units (ICU). Since the publication of large randomized controlled trials indicating negative effects on renal function, their use has been questioned, especially for hydroxyethyl starch products. The preliminary assumption that these side effects are only existent in first or secondary generation starch fluids was proven incorrect. In fact, the use of hydroxyethyl starch products in critically ill patients is prohibited by the European Medicines Agency.

CURRENT DISCUSSION AND INDICATIONS

Several methodological limitations exist in each of these trials that limit the evidence value of these investigations, although they served as the basis for the negative judgment of the European Medicines Agency. In addition, a large randomized controlled trial on the efficacy of gelatin is lacking. The use of colloids in ICU patients is indicated in cases where crystalloid volume therapy is inadequate.

CONCLUSION

Especially during the first 6 h of sepsis, when aggressive volume therapy is decisive for patient outcome, colloids may be relevant to increase patient survival. The latest guideline on treatment with colloids has been published in the German S3 guideline "Intravascular volume therapy in adults."

Crystalloids versus colloids for fluid resuscitation in critically-ill patients

The choice of crystalloid or colloid for fluid resuscitation has been debated for the last few years. Although colloids seems to be more interesting when taking into account their physiological properties, their effect on mortality is not better than crystalloids if they are used in an adequate amount. Moreover, colloids' side effects are far more important than those of crystalloids. Several randomised studies pointed out the renal effects of colloids including acute renal injury with an increased need of renal replacement therapy. An unacceptably high rate of renal side effects has resulted in premature termination of some clinical trials. In addition, homeostatic and anaphylactoid effects of colloids on coagulation and on anaphylaxis may increase the risk of death associated with their use. Finally, colloids are much more expensive than crystalloids. For all these reasons, we conclude that crystalloids should be preferred to colloids for fluid resuscitation.

Effects of intraoperative colloid administration on outcome in a population-based general surgical cohort: a propensity score analysis

BACKGROUND

Many studies on colloids have recently been retracted, leaving us with uncertain evidence of their safety. We aimed to analyze whether intraoperative colloid administration is associated with postoperative complications.

METHODS

The prospectively compiled database of the ARISCAT study of a large, representative cohort of general surgical patients was reanalyzed to compare outcomes according to whether intraoperative colloids were administered or not; a propensity score was used to adjust for potential confounders. The primary outcomes were major postoperative complications. Secondary outcomes were postoperative hospital-free days within 90 days and mortality at 30 and 90 days. In a retrospective survey we asked each center's data collectors to estimate the proportions of the different colloids administered during the study period.

RESULTS

Of 2462 patients analyzed, 556 (22.6%) received some type of colloid intraoperatively. The median (25th-75th percentile) of total fluids administered was significantly higher in patients receiving colloids (10.0 [6.9-14.1] mL·kg-1·h-1 vs. 8.8 [6.0-12.8] mL·kg-1·h-1 for patients not receiving colloids; P<0.01). The median volume of colloids administered was 7.5 (6.3-10.4) mL·kg-1. An estimated 75.7% of the patients received third-generation hydroxyethyl starches (130/0.4). Significantly associated complications, after propensity score adjustment, were atelectasis, respiratory infection, bronchospasm, arrhythmia, sepsis, paralytic ileum, and hyperglycemia. Patients receiving colloids had 1.9 fewer postoperative hospital-free days (P<0.006). There were no significant differences in 30- and 90-day mortality.

CONCLUSION

Our study suggests an association of intraoperative colloid administration, mainly of 130/0.4 hydroxyethyl starches, with diverse major postoperative complications and longer hospital stay. Controlled studies are urgently needed to assess the safety profile of colloid use in surgical patients.

High dosage of dextran 70 is associated with severe bleeding in patients admitted to the intensive care unit for septic shock

INTRODUCTION

Synthetic colloids are frequently used in fluid resuscitation of septic patients. Despite this, little is known about the potential side effects including the risk of renal failure and bleeding. As practice has changed, we performed a before-and-after study of fluid resuscitation and outcome in patients with septic shock.

MATERIAL AND METHODS

We retrospectively assessed all adult patients with septic shock admitted to a general intensive care unit (ICU) at a tertiary hospital in the years 2006 and 2008. Data on patient characteristics, resuscitation fluids in the ICU and outcome were collected from electronic databases and patient files.

RESULTS

A total of 332 patients with septic shock were included: 171 in 2006 and 161 in 2008. The use of mainly dextran 70 in 2006 (median 3.5 (interquartile range 1.9-7.1) versus 1.5 (0.5-3.0) l, p < 0.0001; 44 (24-86) versus 18 (8-42) ml/kg, p < 0.0001) had changed to mainly crystalloids (Ringer's lactate 0 (0.0-0.3) versus 1.1 (0.0-3.0) l, p < 0.0001) and albumin (5%, 0.0 (0.0-1.0) versus 0.8 (0.0-1.5) l, p < 0.0001; 20%, 0.0 (0.0-0.3) versus 0.1 (0.0-0.4) l, p < 0.0001) in 2008. There were no differences in rates of renal replacement therapy or 90-day mortality, but more patients experienced severe bleeding in 2006 than in 2008 (30 versus 19%, p = 0.03). Also more red blood cells, plasma and platelets were given in 2006 than in 2008 (p < 0.01 for all).

CONCLUSION

In patients with septic shock, fluid treatment had changed from mainly dextran 70 in 2006 to crystalloids and albumin in 2008. The administration of high-dosage dextran 70 was associated with more patients experiencing severe bleeding.

FUNDING

not relevant.

TRIAL REGISTRATION

not relevant.

Colloid solutions for fluid resuscitation

BACKGROUND

Colloids are widely used in the replacement of fluid volume. However doubts remain as to which colloid is best. Different colloids vary in their molecular weight and therefore in the length of time they remain in the circulatory system. Because of this and their other characteristics, they may differ in their safety and efficacy.

OBJECTIVES

To compare the effects of different colloid solutions in patients thought to need volume replacement.

SEARCH METHODS

We searched the Cochrane Injuries Specialised Register (searched 1 Dec 2011), Cochrane Central Register of Controlled Trials 2011, issue 4 (The Cochrane Library); MEDLINE (Ovid) (1948 to November Week 3 2011); EMBASE (Ovid) (1974 to 2011 Week 47); ISI Web of Science: Science Citation Index Expanded (1970 to 1 Dec 2011); ISI Web of Science: Conference Proceedings Citation Index-Science (1990 to 1 Dec 2011); CINAHL (EBSCO) (1982 to 1 Dec 2011); National Research Register (2007, Issue 1) and PubMed (searched 1 Dec 2011). Bibliographies of trials retrieved were searched, and for the initial version of the review drug companies manufacturing colloids were contacted for information (1999).

SELECTION CRITERIA

Randomised controlled trials comparing colloid solutions in critically ill and surgical patients thought to need volume replacement.

DATA COLLECTION AND ANALYSIS

Two authors independently extracted the data and assessed the quality of the trials. The outcomes sought were death, amount of whole blood transfused, and incidence of adverse reactions.

MAIN RESULTS

Ninety trials, with a total of 5678 participants, met the inclusion criteria. Quality of allocation concealment was judged to be adequate in 35 trials and poor or uncertain in the rest.Deaths were obtained in 61 trials. For albumin or PPF versus hydroxyethyl starch (HES) 32 trials (n = 1769) reported mortality. The pooled relative risk (RR) was 1.07 (95% CI 0.87 to 1.32). When the trials by Boldt were removed from the analysis the pooled RR was 0.90 (95% CI 0.68 to 1.20). For albumin or PPF versus gelatin, nine trials (n = 824) reported mortality. The RR was 0.89 (95% CI 0.65 to 1.21). Removing the study by Boldt from the analysis did not change the RR or confidence intervals. For albumin or PPF versus Dextran four trials (n = 360) reported mortality. The RR was 3.75 (95% CI 0.42 to 33.09). For gelatin versus HES 25 trials (n = 1756) reported mortality and the RR was 1.03 (95% CI 0.84 to 1.26). When the trials by Boldt were removed from the analysis the pooled RR was 1.04 (95% CI 0.85 to 1.27). RR was not estimable in the gelatin versus dextran and HES versus dextran groups.Forty five trials recorded the amount of blood transfused, however quantitative analysis was not possible due to skewness and variable reporting. Twenty-four trials recorded adverse reactions, with two studies reporting possible adverse reactions to Gel and one to HES.

AUTHORS' CONCLUSIONS

From this review, there is no evidence that one colloid solution is more effective or safe than any other, although the confidence intervals are wide and do not exclude clinically significant differences between colloids. Larger trials of fluid therapy are needed if clinically significant differences in mortality are to be detected or excluded.

[Morphological changes of the intestine in experimental acute intestinal infection in the treatment of colloidal silver]

At the present stage of infectionist practice in the treatment of acute intestinal infections caused by opportunistic microorganisms, colloidal silver is used with a particle size of 25 nm as an alternative to conventional causal therapy. In 32 rats, distributed in 4 groups of 8 animals each (intact; healthy, got colloidal silver; with a modeled acute intestinal infection in the basic treatment and with the addition of colloidal silver), histological examination was performed of small and large intestine of rats. Oral administration of colloidal silver at a dose of 0.02 mg/day to intact rats did not lead to changes in morphometric parameters compared to the norm, and during early convalescence in rats with acute intestinal infections were observed destructive and compensatory changes in the intestine, which depended on the treatment regimen. With the introduction of colloidal silver decreased activity of the inflammatory process and the severity of morphological changes in tissues of small and large intestine, indicating that the positive effect of study drug compared with baseline therapy.

[The "Seville" Consensus Document on Alternatives to Allogenic Blood Transfusion. Sociedades españolas de Anestesiología (SEDAR), Medicina Intensiva (SEMICYUC), Hematología y Hemoterapia (AEHH), Transfusión sanguínea (SETS) Trombosis y Hemostasia (SETH)]

The Consensus Document on Alternatives to Allogenic Blood Transfusion (AABT) has been drawn up by a panel of experts from 5 scientific societies. The Spanish Societies of Anesthesiology (SEDAR), Critical Care Medicine and Coronary Units (SEMICYUC), Hematology and Hemotherapy (AEHH), Blood Transfusion (SETS) and Thrombosis and Hemostasis (SETH) have sponsored and participated in this Consensus Document. Alternatives to blood transfusion have been divided into pharmacological and non-pharmacological, with 4 modules and 12 topics. The main objective variable was the reduction of allogenic blood transfusions and/or the number of transfused patients. The extent to which this objective was achieved by each AABT was evaluated using the Delphi method, which classifies the grade of recommendation from A (supported by controlled studies) to E (non-controlled studies and expert opinion). The experts concluded that most of the indications for AABT were based on middle or low grades of recommendation, "C", "D", or "E", thus indicating the need for further controlled studies.

Nanoparticles and colloids as contributing factors in neurodegenerative disease

This review explores the processes underlying the deleterious effects of the presence of insoluble or colloidal depositions within the central nervous system. These materials are chemically unreactive and can have a prolonged residence in the brain. They can be composed of mineral or proteinaceous materials of intrinsic or exogenous origin. Such nanoparticulates and colloids are associated with a range of slow-progressing neurodegenerative states. The potential common basis of toxicity of these materials is discussed. A shared feature of these disorders involves the appearance of deleterious inflammatory changes in the CNS. This may be due to extended and ineffective immune responses. Another aspect is the presence of excess levels of reactive oxygen species within the brain. In addition with their induction by inflammatory events, these may be further heightened by the presence of redox active transition metals to the large surface area afforded by nanoparticles and amphipathic micelles.

Colloid solutions for fluid resuscitation

BACKGROUND

Colloids are widely used in the replacement of fluid volume. However doubts remain as to which colloid is best. Different colloids vary in their molecular weight and therefore in the length of time they remain in the circulatory system. Because of this and their other characteristics, they may differ in their safety and efficacy.

OBJECTIVES

To compare the effects of different colloid solutions in patients thought to need volume replacement.

SEARCH STRATEGY

We searched the Cochrane Injuries Group's specialised register, CENTRAL (2007, Issue 1), MEDLINE (1994 to March 2007), EMBASE (1974 to March 2007), and the National Research Register (2007, Issue 1). Bibliographies of trials retrieved were searched, and drug companies manufacturing colloids were contacted for information. The search was last updated in March 2007.

SELECTION CRITERIA

Randomised and quasi-randomised trials comparing colloid solutions in critically ill and surgical patients thought to need volume replacement. The outcomes measured were death, amount of whole blood transfused, and incidence of adverse reactions.

DATA COLLECTION AND ANALYSIS

Two authors independently extracted the data and assessed the quality of the trials.

MAIN RESULTS

Seventy trials, with a total of 4375 participants, met the inclusion criteria. Quality of allocation concealment was judged to be adequate in 24 trials and poor or uncertain in the rest.Deaths were obtained in 46 trials. For albumin or PPF versus hydroxyethyl starch (HES) 25 trials (n = 1234) reported mortality. The pooled relative risk (RR) was 1.14 (95% CI 0.91 to 1.43). When the trials by Boldt are removed from the analysis the pooled RR was 0.97 (95% CI 0.70 to 1.35). For albumin or PPF versus gelatin, seven trials (n = 636) reported mortality. The RR was 0.97 (95% CI 0.68 to 1.39). For albumin or PPF versus Dextran four trials (n = 360) reported mortality. The RR was 3.75 (95% CI 0.42 to 33.09). For gelatin versus HES 18 trials (n = 1337) reported mortality and RR was 1.00 (95% CI 0.80 to 1.25). RR was not estimable in the gelatin versus dextran and HES versus dextran groups.Thirty-seven trials recorded the amount of blood transfused, however quantitative analysis was not possible due to skewness and variable reporting. Nineteen trials recorded adverse reactions, but none occurred.

AUTHORS' CONCLUSIONS

From this review, there is no evidence that one colloid solution is more effective or safe than any other, although the confidence intervals are wide and do not exclude clinically significant differences between colloids. Larger trials of fluid therapy are needed if clinically significant differences in mortality are to be detected or excluded.

[Pre- and intra-hospital over-resuscitation in burns: frequent and deleterious]

Major burns are characterized by an initial capillary leak which requires fluid resuscitation for hemodynamic stabilisation. While under-resuscitation was the major cause of death until the 80ies, over-resuscitation has become an important source of complications: abdominal compartment syndrome, escharotomies, impaired gas exchange and prolonged mechanical ventilation and hospital stay. The fluid creep started in the 90ies with an increasing proportion of the first 24 hours' fluid delivery above the 4 ml/kg/% BSA Parkland prediction. The first alerts were published under the form of case reports of increased mortality due to abdominal compartment syndrome and respiratory failure. The paper analyses the causes of this fluid creep, and the ways to prevent it, which includes rationing prehospital fluid delivery, avoiding early colloids and permissive hypovolemia.

Fluid resuscitation: past, present, and the future

Hemorrhage remains a major cause of preventable death following both civilian and military trauma. The goals of resuscitation in the face of hemorrhagic shock are restoring end-organ perfusion and maintaining tissue oxygenation while attempting definitive control of bleeding. However, if not performed properly, resuscitation can actually exacerbate cellular injury caused by hemorrhagic shock, and the type of fluid used for resuscitation plays an important role in this injury pattern. This article reviews the historical development and scientific underpinnings of modern resuscitation techniques. We summarized data from a number of studies to illustrate the differential effects of commonly used resuscitation fluids, including isotonic crystalloids, natural and artificial colloids, hypertonic and hyperoncotic solutions, and artificial oxygen carriers, on cellular injury and how these relate to clinical practice. The data reveal that a uniformly safe, effective, and practical resuscitation fluid when blood products are unavailable and direct hemorrhage control is delayed has been elusive. Yet, it is logical to prevent this cellular injury through wiser resuscitation strategies than attempting immunomodulation after the damage has already occurred. Thus, we describe how some novel resuscitation strategies aimed at preventing or ameliorating cellular injury may become clinically available in the future.

The influence of colloids on the geochemical behavior of metals in polluted water using as an example Yongdingxin River, Tianjin, China

The role of colloids in estuarine and marine systems has been studied extensively in recent years, whereas less is known about the polluted freshwater system. Yongdingxin River is one of the major recipients of industrial effluents in Tianjin. This article evaluates the role of colloids in controlling geochemical behavior of Cu, Zn, Fe, Mn, Hg and Cr at the confluences between Yongdingxin River and its major tributaries Beijing Drainage River, Jinzhong River and Beitang Drainage River. Based on the distribution of metal partitioning among particulate (>0.22mum), colloidal (1kDa to 0.22mum) and truly dissolved (<1kDa) fractions, the metals can be assigned to the following groups: Group 1 - organic colloidal pool-borne elements Cu and Cr; Group 2 - inorganic colloidal pool-borne metals Fe and Mn; Group 3 - Zn and Hg characterized by varying complexation patterns. The distribution of metal partitioning among particulate, colloidal and truly dissolved fractions was influenced by anthropogenic input. In addition, the theoretical concentrations of elements in case of conservative mixing between the waters of Yongdingxin River and the waters of its tributaries were compared with the measured values to evaluate the geochemical role of colloids. The result showed that all of the metals presented a non-conservative mixing behavior. Addition of colloids resulted in the removal of metals from the water column to bed sediment during river water mixing, which was furthermore confirmed by the similar partition coefficient of metal concentration between colloid and sediment.

[The design of the VISEP trial. Critical appraisal]

The survey transcript of the VISEP interventional trial "Prospective randomized multicenter study on the influence of colloid vs crystalloid volume resuscitation and of intensive vs conventional insulin therapy on outcome in patients with severe sepsis and septic shock" [Clinical trials.gov. identifier: NCT00135473; study start April 2003] comprises, according to the data of the year 2003, methodological shortcomings which challenge a priori the study design and thus the resolution of the purpose of the study, i.e., "determination of the influence of the studied volume and insulin interventions on morbidity and mortality of patients with severe sepsis and septic shock". The most important points of criticism are: 1. A volume therapy with exclusively crystalloids or colloids with the chosen colloid hyperoncotic, hyperchloremic HES solution (10% hydroxyethyl starch: 10% Hemohes) or the crystalloid solution with high lactate content (Sterofundin) is neither acceptable nor practicable, even if only due to exceeding the maximum dosage as recommended by the manufacturer. 2. The fact known since the year 2001 that high molecular weight, poorly biodegradable HES preparations can present an independent risk-factor for acute kidney failure in patients with sepsis or septic shock was ignored: the exclusion criterion of a serum-creatinine value of >320 micromol/l (>3.6 mg/dl) was doubled in relation to the manufacturer's specification. 3. The hyperoncotic colloid solution used (10% Hemohes) may only be employed for a brief period: it is highly hyperchloremic and causes extravascular hypohydration with consecutive reduction of renal excretion, which together with HES is a fatal combination. 4. The crystalloid solution used, i.e., Sterofundin, which contains 45 mmol/l lactate, is contraindicated with septic shock as it increases the patient's O2 consumption, hinders lactate diagnostics as a hypoxia marker by simultaneous lactate infusion, and through increased gluconeogenesis leads to hyperglycemia, at least with diabetics. 5. It is doubtful whether an intensified insulin therapy (Actrapid) can be successful if insulin is administered simultaneously with iatrogenic hyperglycemia as a result of lactate influx. Due to these flaws in the design of the VISEP trial, the only consequence can be that the results of the survey are unusable, especially with regard to the point "HES and kidney function". Thus, any further advance presentations and interpretations should be shelved in expectation of the authors' publication of all the data, in order to begin further discussions including the flaws in study design listed here.

Gelatin colloids in the resuscitation of trauma

To date, the specific role of gelatins in trauma resuscitation remains under-investigated. Their adverse affects are well described and relate principally to the provocation of allergic responses whilst their influence upon haemostasis is relatively benign in comparison to the other colloids. However, their benefits are only sparsely documented and the evidence to choose one gelatin over another virtually non-existent. As knowledge of the microcirculatory dysfunction inherent in the shocked state increases, the role of the gelatins in trauma resuscitation is being increasing sidelined by other colloids--notably the starches. Their role beyond a basic resuscitation tool is now uncertain.

Irreversible hydrocolloid: an unusual presentation of esophageal obstruction

Upper digestive tract obstruction can occur after ingestion of various types of foreign bodies. However to the best of our knowledge, no case of a near-total obstruction caused by an irreversible hydrocolloid has heretofore been reported in the literature. We present just such a case, and we discuss our preferred method of removing foreign bodies from the cervical esophagus.

[Perioperative colloid administration: a survey of Spanish anesthesiologists' attitudes]

OBJECTIVES

To determine the availability of intravascular fluid volume replacement solutions in Spanish hospitals, to survey the extent of use of colloids by anesthesiologists, to ascertain the possible adverse effects they seek to prevent when using each solution, and to assess their level of knowledge about the subject.

MATERIAL AND METHODS

A questionnaire was administered over a period of 6 months (July 2004-January 2005). The questionnaire was available online at www.encuestacoloides.com. The address was distributed by e-mail to anesthesiologists of all the Spanish autonomous communities and published in the Revista Española de Anestesiología y Reanimación.

RESULTS

One hundred forty-two anesthesiologists responded. Crystalloids and colloids were widely available in most hospitals. Hydroxyethyl starch (HES) solutions were the colloids most often used (73%), followed by gelatins (28%). Dextran solutions, on the other hand, were no longer being used. The reasons the respondents gave for using these solutions were related to the time they remained in the vascular system, their greater effect of volume expansion, and the preservation of hemostasis. The most-feared complication was anaphylactic reaction to gelatins and there were concerns about the dose limit for infusion of HES solutions and about hemodynamic instability caused by dextran solutions. Fifty-four percent felt that scientific meetings provide little information about colloids and volume replacement.

CONCLUSIONS

There is widespread use of colloids other than dextran along with crystalloids for plasma volume replacement. Spanish anesthesiologists are clear about important concepts related to colloid use. However, a high percentage have doubts about certain fundamental issues. Continuing professional development opportunities related to intravascular fluid replacement therapy should be increased.

Diagnosing and management of iatrogenic moderate and severe ovarian hyperstymulation syndrome (OHSS) in clinical material

Severe ovarian hyperstymulation syndrome is a rare but potentially life-threatening complication in patients undergoing assisted reproductive techniques (ART). The pathogenesis of this condition is likely to be multifactorial. The aim of the retrospective study was to present management in moderate and severe iatrogenic ovarian hyperstymulation syndrome (OHSS) in clinical material. The study group was 19 women, admitted to the Department of Obstetrics and Gynecology in Central Clinical Hospital of Ministry of Interior and Administration in Warsaw from large outpatient infertility center "Novum" in Warsaw with moderate and severe OHSS between 14.07.2004 and 8.11.2005. Laboratory tests and ultrasound examination of the ovarian size and ascites were performed, abdominal circumference was measured. Patients were treated with rehydration with intravenous crystalloids and colloids, diuretics, antibiotics, anticoagulants and ultrasound-guided paracentesis if symptoms of ascites become severe (ascites causes pain and compromised pulmonary function). Oral intake of water was restricted, monitoring of fluid intake and output, and daily monitoring of body weight was performed. During treatment controlled laboratory tests were done. In one patient occurred intra-abdominal hemorrhage from ovarian rupture and laparotomy with oophorectomy was performed. The ovarian hyperstimulation syndrome is still a difficult diagnostic and therapeutic problem and more studies are required to elucidate pathophysiology of OHSS. Because of still unknown etiology treatment is empirical and in most of cases bases on experience of medical team. Thus, the management in individual patients varies according to the severity of ovarian hyperstymulation syndrome and its complications.

[Criteria for the safety of transfusion of colloidal solutions in patients with acute lung lesions]

The prospective study explored the hemodynamic effects of colloidal solution replacement therapy and the criteria for its safety in patients with acute lung parenchymatous lesions (ALPL) attended by hypoalbuminemia and coagulopathy. There were 68 observations of the effects of colloidal solutions: 20% albumin solution (n=25), freshly frozen plasma (FFP) (n=20), 6% hydroxyethylated starch (HES) 130/0.4 9:1 (n=23). The colloidal solutions were infused at a constant rate; the infusion was stopped until pulmonary wedge pressure (PWP) was 25% greater than its baseline value. Before and after infusion, the parameters of central hemodynamics and oxygen transport, extravascular lung water index (ELWI), pulmonary vascular permeability index (PVPI), and colloid-osmotic pressure (COP) were measured. The infusion volumes were 3.8 +/- 0.4, 13.7 +/- 1.4, and 13.4 +/- 1.3 ml/kg for 20% albumin solution, 6% HES 130/0.4, and FFP, respectively. The PWP-COP gradient increased in all groups. After FFP infusion, there was an increase in ELWI and lung shunt. After 20% albumin solution, there was a delayed increase in ELWI. There was no rise in ELWI after 6% HES administration. In the 20% albumin solution group, the increased ELWI was recorded in patients who had positive baseline PWP-COP gradients (p < 0.05). A combination of higher PVPI and a positive PWP-COP value causes a greater increase in ELWI after 20% albumin solution infusion than in the normal PVPI group. In patients with ALPL, FFP infusion may lead to an increase in the accumulation of extravascular lung water. A negative preinfusion PWP-COP gradient is a safety criterion for the infusion of 20% albumin solution in patients with ALPL. The increased PVPI in combination with a positive PWP-COP gradient is an aggravating factor.

Dermal and mucosal reactions to an antimicrobial irreversible hydrocolloid impression material: A clinical report

As an adjunct to infection control in dental impression procedures, several manufacturers have incorporated disinfectants into irreversible hydrocolloid impression materials. However, these compounds have been shown to be tissue irritants and capable of producing allergic reactions. An anonymous, self-administered questionnaire was distributed to 56 second-year dental students who had used an irreversible hydrocolloid containing a quaternary ammonium compound as an antimicrobial (Jeltrate Plus) to make impressions during a summer preclinical occlusion course. Within the limitations of this report, the incorporation of a quaternary ammonium compound into an irreversible hydrocolloid impression material resulted in a greater incidence of dermal and mucosal irritation.

Effect of fluid loading with saline or colloids on pulmonary permeability, oedema and lung injury score after cardiac and major vascular surgery

BACKGROUND

The optimal type of fluid for treating hypovolaemia without evoking pulmonary oedema is still unclear, particularly in the presence of pulmonary vascular injury, as may occur after cardiac and major vascular surgery.

METHODS

In a single-centre, prospective, single-blinded clinical trial 67 mechanically ventilated patients were randomly assigned to receive saline, gelatin 4%, HES 6% or albumin 5%, according to a 90 min fluid loading protocol with target central venous pressure of 13 and pulmonary capillary wedge pressure of 15 mm Hg, within 3 h after cardiac or major vascular surgery. Before and after the protocol, we recorded haemodynamics and ventilatory variables and took chest radiographs. The pulmonary vascular injury was evaluated using the 67Ga-transferrin pulmonary leak index (PLI) and extravascular lung water (EVLW). Plasma colloid osmotic pressure (COP) was determined and the lung injury score (LIS) was calculated.

RESULTS

More saline was infused than colloid solutions (P<0.005). The COP increased in the colloid groups and decreased in patients receiving saline. Cardiac output increased more in the colloid groups. At baseline, PLI and EVLW were above normal in 60 and 30% of the patients, with no changes after fluid loading, except for a greater PLI decrease in HES than in gelatin-loaded patients. The oxygenation ratio improved in all groups. In the colloid groups, the LIS increased, because of a decrease in total respiratory compliance, probably associated with an increase in intrathoracic plasma volume.

CONCLUSIONS

Provided that fluid overloading is prevented, the type of fluid used for volume loading does not affect pulmonary permeability and oedema, in patients with acute lung injury after cardiac or major vascular surgery, except for HES that may ameliorate increased permeability. During fluid loading, changes in LIS (and respiratory compliance) do not represent changes in pulmonary permeability or oedema.

Skin changes induced by a zinc oxide dressing compared with a hydrocolloid dressing in healthy individuals

BACKGROUND/PURPOSE

Incidence of skin complications in ostomy patients constitutes a well-known and well-described problem. The reasons are, however, very difficult to describe because of the many factors contributing to the problem. This article describes the skin changes derived exclusively from the adhesives used in a carefully controlled, long-term study using two fundamentally different types of adhesives: a hydrocolloid adhesive and a zinc oxide adhesive.

METHODS

The adhesives were changed daily on the volar forearm of 11 volunteers for a 4-week period. Once a week, transepidermal water-loss (TEWL), water content of the skin, erythema and the peel force applied for removal of the adhesives were measured. On the last day of the study, a replica of the skin surface was obtained to determine changes in the skin topography, and a biopsy was taken to study changes at the cellular level.

RESULTS AND CONCLUSION

We found increased TEWL and decreased water content in skin treated with the zinc oxide adhesive, but increased water-loss and water content when the hydrocolloid adhesive was used. In addition, the area treated with zinc oxide adhesive showed significant increase of epidermal thickness, scaly appearance and parakeratosis with similarities to pathological dry skin diseases such as psoriasis and atopic dermatitis, changes that were not found when using the hydrocolloid adhesive. The skin response seems to be the result of the content of zinc oxide and the mechanical interaction of the zinc oxide adhesive. We conclude that the nature of the adhesive plays an important role in the skin response to repeated application of adhesives, as seen in peristomal skin.

Artificial colloids impair haemostasis. An in vitro study using thromboelastometry coagulation analysis

BACKGROUND

Hydroxyethyl starch (HES) solutions impair haemostatic mechanisms. The impact of the degree of substitution (DS) of a HES solution on thromboelastometry tracings is unclear. Therefore we tested the hypothesis of whether the DS has an effect on the haemostatic defect caused by HES, and assessed whole blood coagulation by thromboelastometry coagulation analysis (ROTEM, Pentapharm Co., Munich, Germany) in serial in vitro haemodilutions of colloids.

METHODS

Whole blood was withdrawn from 12 volunteers in a crossover study. Six per cent low-molecular weight HES with a high (HES MW 120 kDa/degree of substitution 0.7) and low (HES MW 130 kDa/0.4) degree of substitution, 4% succinylated gelatin (GEL) or 4% albumin (ALB) was added to citrated venous whole blood samples to make 20, 40, 60 vol.% end-concentrations of each of the solutions. Samples were analyzed by ROTEM.

RESULTS

There was a comparable decrease in maximum clot firmness (MCF) and shear elastic modulus [G = 5000 x MCF/(100-MCF)] by HES 120/0.7 and HES 130/0.4 at 20 and 40 vol.% dilutions. At 60 vol.% dilution HES 120/0.7 decreased less alpha-angle and MCF than HES 130/0.4 (P < 0.05). With moderate dilutions all colloids shortened coagulation time (CT). At 20, 40 and 60 vol.% dilutions MCF and G were more decreased in both HES groups than in the ALB and GEL groups (P < 0.05). Furthermore, at 40 and 60 vol.% dilutions G deteriorated more in the GEL than in the ALB group (P < 0.05).

CONCLUSION

In vitro the impact of the degree of substitution of HES solution on thromboelastometry coagulation analysis was modest. Haemodilution with gelatin and albumin induced fewer coagulation abnormalities than HES. In addition, the haemodilution with gelatin impaired coagulation more than albumin solution.

Cytotoxicity of colloidal CdSe and CdSe/ZnS nanoparticles

Cytotoxicity of CdSe and CdSe/ZnS nanoparticles has been investigated for different surface modifications such as coating with mercaptopropionic acid, silanization, and polymer coating. For all cases, quantitative values for the onset of cytotoxic effects in serum-free culture media are given. These values are correlated with microscope images in which the uptake of the particles by the cells has been investigated. Our data suggest that in addition to the release of toxic Cd(2+) ions from the particles also their surface chemistry, in particular their stability toward aggregation, plays an important role for cytotoxic effects. Additional patch clamp experiments investigate effects of the particles on currents through ion channels.

Hydroxyethyl starch--can the safety problems be ignored?

Hydroxyethyl starch (HES) has come into widespread use for fluid management of acutely ill patients. Certain characteristic complications of HES, notably renal impairment, hemorrhage and pruritus, have been well documented with all types of HES solutions. The use of HES solutions with lower molecular weight and substitution has been claimed to minimize these safety risks. In particular, solutions of 200 kDa molecular weight and 0.5 substitution (HES 200/0.5) and of 130 kDa molecular weight and 0.4 substitution (HES 130/0.4) have been advocated for their superior safety profile. A critical appraisal of the available evidence does not provide reassurance that these or other HES solutions are risk free. Most evidence indicates the equivalence of HES 200/0.5 and HES 130/0.4 with respect to effectiveness for volume expansion. Since HES 130/0.4 is newer, its safety profile is less well characterized; however, it appears to share the same complication risks as those of HES 200/0.5. In randomized clinical trials employing sensitive markers, both HES 200/0.5 and HES 130/0.4 have been shown to impair renal function. Both coagulopathy and clinical bleeding have been documented after administration of either HES 200/0.5 or HES 130/0.4, and the magnitude of negative effects on hemostasis has been similar for these two HES solutions. Pruritus is a common side effect of all HES solutions, including HES 200/0.5 and HES 130/0.4, and can occur in diverse clinical settings in some cases after only small HES doses. Typically presenting as pruritic crises of delayed onset, this complication is often severe, protracted and refractory to treatment. An additional risk of HES infusion is the occurrence of potentially life-threatening anaphylactoid reactions, which are 4.5 times as frequent after HES as albumin exposure. Limiting the dose and duration of HES therapy may be helpful in lessening the risk of undesired side effects; at present however, reliance on particular HES solutions does not appear sufficient to ensure safety.

Advantages and disadvantages of colloid and crystalloid fluids

Plasma volume expanders--crystalloid, colloid, or a mixture of both--are used as fluid replacement in patients who have postoperative hypovoloaemia. Despite numerous clinical trials there is little evidence that either classification of plasma volume expander is more beneficial to mortality than the other.

Toxicity and Antimicrobial Activity of a Hydrocolloid Dressing Containing Silver Particles in an ex vivo Model of Cutaneous Infection

In the present study we examined the effects of two hydrocolloid wound dressings (conventional silver-free Comfeel, silver-incorporating Contreet-H) on uninfected and Candida albicans- or methicillin-resistant Staphylococcus aureus-infected reconstituted human epithelium (RHE). The morphological alterations of the keratinocytes caused by infection and by treatment were analysed with light and electron microscopy. As a measure of epithelial cell damage the release of lactate dehydrogenase from epithelial cells into the surrounding medium was monitored. Application of Contreet-H or Comfeel to uninfected RHE induced no major morphological effects on epithelial cells. Both wound dressings reduced the growth of micro-organisms. Specific alterations of the infected epithelium (vacuoles, spongiosis, oedema, detachment of keratinocytes) and invasion of the epithelium were significantly reduced only by treatment with Contreet-H. At the ultrastructural level release of silver by Contreet-H and superior antimicrobial efficacy could be verified. In summary, treatment with both wound dressings reduced the number of pathogens, with the silver-based wound dressing providing a more effective antimicrobial activity. This resulted in a strong decrease of pathogen-specific alterations of the infected epithelium. We present evidence that delivering silver to infected keratinocytes in a moist healing environment improves the benefit/risk ratio as compared to silver-free wound dressings.

Evaluation of a new composite dressing for the management of chronic leg ulcer wounds

OBJECTIVES

A new composite dressing (Versiva, ConvaTec) combines three technologies: hydrocolloid, hydrofibre and a foam-film layer. This study aimed to assess the safety of the dressing in the management of patients with venous leg ulcers. Clinical performance was also assessed.

METHOD

This multicentre, non-randomised, open-label, phase II study assessed the safety (via adverse-effect reporting) and performance, including weartime, absorption, dressing integrity, ease of use and wound progression, of Versiva. Up to 10 dressing changes were assessed within a five-week study period.

RESULTS

In 75 dressing changes of 11 ulcers, the mean wear time was approximately five days. No or minimal leakage was observed in 81% of changes. In 93%, the dressing was 'very easy' to remove, with no trauma to surrounding skin. Most changes (77%) were painless.

CONCLUSION

Versiva met or exceeded the investigators' expectations for exudate absorption, protection of peri-wound skin and reduction in wound pain and ulcer area. Healing or marked improvement was observed in 82% of leg ulcers within the five-week study. The relatively long wear-time of five days represents a cost-effective advantage for this dressing compared with other available adhesive foams for the management of chronic wounds.

Risk of hemorrhage from unsecured, unruptured aneurysms during and after hypertensive hypervolemic therapy

OBJECTIVE

Hypertensive hypervolemic therapy for vasospasm is widely practiced. It is not clear, however, whether the use of hypertension and hypervolemia as a treatment for vasospasm risks hemorrhage from an unsecured, unruptured aneurysm.

METHODS

From 1991 to 2000, the neurovascular unit at the Massachusetts General Hospital treated 1908 aneurysms, of which 966 were ruptured. Forty patients with ruptured aneurysms had unsecured, unruptured aneurysms and underwent hypertensive hypervolemic therapy for vasospasm. Hypertension was induced by intravenously administered phenylephrine, norepinephrine, and/or dopamine, and hypervolemia was achieved by intravenously administered crystalloid and colloid solutions. The 24-hour mean arterial systolic blood pressure (SBP) and the 24-hour mean central venous pressure were calculated on the basis of hourly measurements during hypertensive hypervolemic treatment.

RESULTS

The 40 study patients harbored 124 aneurysms, of which 51 aneurysms were treated (clipping, 37; coiling, 14) by the time hypertensive hypervolemic therapy began, leaving 73 unsecured aneurysms at risk. The mean size of the unsecured aneurysms was 4.45 mm. Nineteen patients were treated with mild hypertension (SBP, 140-180 mmHg), 12 patients were treated with moderate hypertension (SBP, 180-200 mmHg), and 9 patients were treated with severe hypertension (SBP, >200 mmHg). The 24-hour mean SBP readings were 166.81 +/- 8.19, 187.57 +/- 5.79, and 204.01 +/- 3.75 mmHg for the mild, moderate, and severe hypertension groups, respectively. The mean central venous pressure was 10.43 +/- 3.89 mmHg. The mean course of hypertensive hypervolemic therapy was 7.25 days, and therapy began on mean post-subarachnoid hemorrhage Day 6.73. Twenty-eight aneurysms were eventually treated in later procedures (clipping, 25; coiling, 3). The mean interval to treatment was 6.93 months. In a treatment and follow-up period of 121.75 aneurysm-years of risk, there was no instance of hemorrhage.

CONCLUSION

Hypertension and hypervolemia do not seem to increase the risk of hemorrhage from unsecured, unruptured aneurysms in the acute setting or in their short-term natural history.

[Allergic contact dermatitis to the Comfeel hydrocolloid dressing]

INTRODUCTION

Allergic contact dermatitis is frequent in patients with chronic leg ulcers. However, it rarely occurs with modern wound dressings and is exceptional with hydrocolloids.

CASE REPORT

A 66-year-old woman was treated for a leg ulcer with the Comfeel plus(R) transparent hydrocolloid dressing for two months. She developed a pruriginous, erythematous and vesiculous dermatitis under the hydrocolloid plaques. Patch tests for the Comfeel plus(R) transparent hydrocolloid, the Comfeel plus(R) hydrocolloid, balsam of Peru and epoxy resin were positive. Only the positive test for the Comfeel plus(R) transparent hydrocolloid was clinically pertinent. The histological examination of the positive test was suggestive of eczema.

DISCUSSION

To our knowledge, allergic contact dermatitis to Comfeel plus(R) hydrocolloid dressings has not been reported. Most previous studies which included systematic patch-testings in patients with leg ulcers showed high sensitization rates for various allergens, but no allergy to hydrocolloids. Only isolated cases of allergic contact dermatitis to another hydrocolloid (Duoderm E(R)) have been reported. Our case report shows that allergic contact dermatitis is a possible side-effect of Comfeel plus(R) hydrocolloid dressings. However, it seems exceptional. Since the patch-tests failed to identify the constituent responsible for this allergy in our observation, comprehensive allergologic investigations should be repeated in further cases.