Randomized, controlled trial on the effect of a 20% mannitol solution and a 7.5% saline/6% dextran solution on increased intracranial pressure after brain injury*

OBJECTIVE

The aim of this pilot study was to compare the effects of equimolar doses of hypertonic saline and dextran solution (HSD, Rescueflow) with 20% mannitol solution for reduction of increased intracranial pressure.

DESIGN

Prospective, randomized, controlled, crossover trial in the intensive care unit of a large teaching hospital.

SETTING

Academic hospital and tertiary referral center for neuroscience.

PATIENTS

Nine patients with an intracranial pressure of >20 mm Hg were recruited and received two treatments of each, HSD and 20% mannitol, in a randomized order.

INTERVENTION

Equimolar, rapid intravenous infusions of either 200 mL of 20% mannitol or 100 mL of 7.5% saline and 6% dextran-70 solution (HSD) over 5 mins.

MEASUREMENTS

Intracranial pressure, blood pressure, serum and urine sodium and osmolality, and urine output.

MAIN RESULTS

Treatments reduced intracranial pressure with both mannitol (median decrease, 7.5 mm Hg, 95% confidence interval, 5.8-11.8) and HSD (median decrease, 13 mm Hg; 95% confidence interval, 11.5-17.3). HSD caused a significantly greater decrease in intracranial pressure than mannitol (p = .044). HSD had a longer duration of effect than mannitol (p = .044).

CONCLUSION

When given in an equimolar, rapid, intravenous infusion, HSD reduces intracranial pressure more effectively than mannitol.

A Systematic Review of the Comparative Safety of Colloids

HYPOTHESIS

Safety differences exist among colloids widely used for fluid management in acutely ill patients, as judged according to the comparative incidence of adverse events.

DATA SOURCES

Colloid safety data for human subjects were sought, without language or time period restrictions, by means of computer searches of bibliographic and clinical trial databases, hand searches of medical journals and Index Medicus, inquiries with investigators and colloid suppliers, and examination of reference lists. Search terms included "colloids", "morbidity", and "mortality".

STUDY SELECTION

Controlled trials, cohort studies, pharmacovigilance studies, and prior meta-analyses were independently selected by 2 unblinded investigators. Of 189 candidate studies, 113 were included, with safety data encompassing 1.54 x 10(6) patients and 1.09 x 10(8) colloid infusions.

DATA EXTRACTION

Two unblinded investigators independently extracted data. Study limitations and confounding factors were tabulated.

DATA SYNTHESIS

With albumin as the reference colloid, the incidence rate ratio for anaphylactoid reactions was 4.51 (95% confidence interval, 2.06-9.89) after hydroxyethyl starch administration, 2.32 (95% confidence interval, 1.21-4.45) after dextran, and 12.4 (95% confidence interval, 6.40-24.0) after gelatin. Pruritus occurrence was significantly increased by hydroxyethyl starch exposure (odds ratio, 1.78; 95% confidence interval, 1.23-2.58). Artificial colloid administration was consistently associated with coagulopathy and clinical bleeding, most frequently in cardiac surgery patients receiving hydroxyethyl starch. On the basis of large-scale pharmacovigilance study results, albumin infusion resulted in a low rate of both total adverse events (3.1 to 8.6 per 10(5) infusions) and serious adverse events (1.29 per 10(6) infusions).

CONCLUSIONS

Significant safety differences exist among colloids. Therefore, conclusions regarding the clinical usefulness of colloids as a fluid class should be formed with caution.

Effects of hypertonic saline-dextran solution in cardiac valve surgery with cardiopulmonary bypass

BACKGROUND

Hypertonic saline-dextran (HSD) solution may be beneficial in patients undergoing coronary artery surgery with cardiopulmonary bypass. Valvular dysfunction is associated with high pulmonary wedge pressure, pulmonary hypertension, and ventricular dysfunction. Fluid overload or transient left ventricular failure may occur with HSD infusion in such patients. This study evaluates the cardiorespiratory effects and tolerance of HSD solution infusion in patients undergoing cardiac valve surgery.

METHODS

This prospective, randomized, double-blind study compared clinical, laboratory, hemodynamic, and respiratory measurements, and fluid balance in 50 patients over a 48-hour period after cardiopulmonary bypass for cardiac valve surgery. Twenty-five patients received 4 mL/kg of HSD during 20 minutes before cardiopulmonary bypass (HSD group). The control group received the same volume of Ringer's solution (Ringer group).

RESULTS

Hospital mortality was zero. The HSD patients had a near zero fluid balance (6.5 +/- 13.5 mL/Kg/48 hours), and the control patients had a positive balance (91.0 +/- 33.7 mL/Kg/48 hours). Hemoglobin was similar in both groups, but more blood transfusions were necessary in the Ringer group (1.21 +/- 1.28 vs 0.48 +/- 0.59 units per patients). The HSD solution induced a higher cardiac index and left ventricular systolic work index postoperatively, and a lower systemic vascular resistance index until 6, 24, and 48 hours. Right ventricular systolic work index increased and pulmonary vascular resistance index decreased after HSD infusion. A better Pao(2)/Fio(2) relation was observed at 1 and 6 hours postoperatively in the HSD group and was associated with a shorter extubation time (432.0 +/- 123.6 vs 520.8 +/- 130.2 minutes). Increased oxygen delivery index occurred in the HSD group. The HSD infusion was well tolerated as none of the patients experienced fluid overload or had left ventricular failure develop. No other complication attributable to the use of HSD solution was observed.

CONCLUSIONS

The HSD solution infusion in patients during cardiac valve surgery with cardiopulmonary bypass was well tolerated. Hemodynamic and respiratory functions improved and fluid balance was near zero during the first 48 hours as compared with a large positive balance in the control group. We conclude that HSD infusion is advantageous for patients undergoing cardiac valve surgery.

Neue Therapieans�tze bei der pr�hospitalen und hospitalen Schockbehandlung

The extreme disturbance of hemodynamics in shock leads to a minimized oxygen delivery to several vital organs. If this state is not rapidly lifted, a multi-organ-failure can occur. In addition to the removal of the underlying causes, for example, bleeding or septic focus, measures must be started to stabilize hemodynamics. In most cases shock can be successfully treated with standard therapeutic interventions including the use of crystalloid or colloid solutions as well as the infusion of inotropes or vasopressors. Up to now, there is not enough evidence to show that hypertonic/hyperoncotic solutions are better for treating hypovolemic shock than standard infusions, other than in situations, where only an inadequate equipment is available. Experimental data support the use of vasopressin instead of fluid loading in case of uncontrolled intra-abdominal bleeding. According to these studies vasopressin seems to be associated with an improved hemodynamic stabilization and a significantly lower mortality rate. However, no clinical tests have been done so far to confirm these results. In septic shock the plasma-levels of vasopressin are low. It has been shown that the infusion of vasopressin contributes to stabilization of hemodynamics in septic shock, in lower, as well as in higher concentrations. On the other hand vasopressin worsens splanchnic perfusion. Therefore the routine use of vasopressin in the treatment of sepsis can not be recommended.

Evaluation of the local irritation potential of hypertonic saline-dextran (HSD) in mice and rabbits

Recent questions have renewed concerns regarding possible irritation associated with intravenous (i.v.) injection of 7.5% hypertonic saline (HS) or hypertonic saline-dextran (HSD: 7.5% NaCl and 6% Dextran-70). This study investigated local injection site irritation associated with i.v., paravenous (p.v.), intramuscular (i.m.) and subcutaneous (s.c.) injection of HSD or its individual components. Mice (n=10 per group per time point) and rabbits (n=10 per group per time point) were infused i.v. with the maximum tolerated dose (28 or 20 ml kg(-1), respectively) of HSD, HS, Dextran-70 (D-70) or lactated Ringer's solution (LR). Animals were observed at 1,2 and 4 h after injection and then twice daily until euthanized on day 3 or 14. In irritation studies, 24 rabbits were randomized to receive the four fluids and they were evaluated histologically at 4, 24, 48 or 72 h after i.v., p.v., i.m. or s.c. infusion. The sites were observed immediately after injection, at 4 h and then twice daily until euthanasia. In surviving mice, bruising of the tail was observed in 6/18 and 5/19 animals in the HSD and HS groups, respectively, compared with 0/20 animals in the D-70 or LR groups. Sloughing of the tail was eventually observed in two HSD-infused and three HS-infused mice, compared with none in the other groups. More bruises, hematomas and blebs were observed after i.v. or s.c. injection of HS and D-70 than LR or HSD in the rabbit irritation studies, but the differences among groups were not statistically significant. In the acute toxicity study in rabbits, bruising at the site of injection was observed in 7/20 and 5/14 surviving animals from the HSD and HS groups, respectively, but none was observed in the LR or D-70 groups. These data suggest that, if infused over 5-10 min into a peripheral or central vein, a therapeutic dose of HSD (4 ml kg(-1)) should not induce any greater inflammation on the vein than LR. However, if significant extravasation of hypertonic fluid occurs, the possibility of localized, focal necrosis might be expected to occur.

Dextran-Related Complications in Head and Neck Microsurgery: Do the Benefits Outweigh the Risks? A Prospective Randomized Analysis

Increased experience with free-tissue transfer has minimized flap loss secondary to microvascular thrombosis, yet pharmacologic antithrombotic prophylaxis continues to be used routinely. Currently there is no consensus on the ideal pharmacologic agent, dosing, or efficacy. Low-molecular-weight dextran has been widely used for prophylaxis due to its properties of volume expansion and enhanced microrheology. Significant systemic morbidity (pulmonary morbidity, cardiac morbidity, anaphylaxis) is known to occur with use of low-molecular-weight dextran. The purpose of this study was to evaluate morbidity associated with postoperative low-molecular-weight dextran and aspirin prophylaxis in head and neck microsurgery patients. This study was a randomized prospective analysis of 100 consecutive patients undergoing microvascular reconstruction for head and neck malignancy during a 2-year period. Patients were randomized into one of three postoperative antithrombotic prophylaxis treatment groups: low-molecular-weight dextran 20 cc/hour for 48 hours (n = 35), low-molecular-weight dextran 20 cc/hour for 120 hours (n = 32), or aspirin 325 mg/day for 120 hours (n = 27). Six patients were excluded intraoperatively due to the need for systemic heparin therapy. Treatment groups were compared for age, sex, prior medical problems, duration of anesthesia, and intraoperative fluid intake. Flap outcome and the incidence of local and systemic complications were evaluated in the treatment groups. Patient ages ranged from 12 to 84 years (mean age, 58 years). No significant difference was found among the treatment groups with respect to age, sex, prior medical problems, duration of anesthesia, intraoperative fluid intake, and the distribution of donor and recipient sites. There were no total flap losses and two partial flap losses in this series. Three flaps were reexplored and all were salvaged. The incidence of systemic complications (congestive heart failure, myocardial infarction, pulmonary edema, pleural effusion, and pneumonia) was as follows: low-molecular-weight dextran 120 hours, 51 percent; low-molecular-weight dextran 48 hours, 29 percent; and aspirin, 7 percent. Analysis of these data suggests that the method of prophylaxis had no effect on overall flap survival. However, the incidence of systemic complications was significantly related to the method of prophylaxis, with patients receiving low-molecular-weight dextran 120 hours and 48 hours at a 7.2 and 3.9 times greater relative risk, respectively, of developing a systemic complication compared with patients receiving aspirin. The results of this study have eliminated the routine use of low-molecular-weight dextran prophylaxis at our institution in an effort to reduce morbidity in head and neck microsurgical reconstruction.

IL-2 loaded dextran microspheres with attractive histocompatibility properties for local IL-2 cancer therapy

Biodegradable dextran microspheres (MS) were developed as a slow-release system for interleukin-2 (IL-2) to apply them for local IL-2 therapy of cancer. We describe the tissue reactions induced by these MS without or with IL-2 in rats. Dextran MS stain bright red-purple with the periodic acid Schiff (PAS), visualising the exact spot of IL-2 release and its relation to the histological reaction pattern. Subcutaneously injected MS always form a well-circumscribed deposit. In the first 2 days there is a PMN inflammation within the MS-deposit, but the surroundings show only a scanty inflammatory reaction. The PMN reaction is replaced by an abundant macrophage reaction in particular in the MS-deposit. At day 21 a fibrous capsule of about 50 mum surrounds the deposit. The effect of IL-2 administered in its free form is mainly vascular, with vascular dilatation, vascular leakage and oedema. It is remarkable that lymphocytes are present in the injection area already at day 2. When IL-2 releasing MS were used, the various reactions induced by IL-2 and MS were amplified leading to local necrosis. We conclude that neither placebo MS nor IL-2 leads to necrosis after subcutaneous injection in rats. In contrast, when IL-2 was released from MS, then massive necrosis was induced. This might be due to increased phagocytosis or changes in the micro-niche due to the release of humoral factors by the infiltrating cells. This is probably fortuitous for local IL-2 therapy of cancer, as massive necrosis of tumour cells can be expected to lead to an increased antitumour reaction.

Epidural Hematoma Associated with Dextran Infusion

The authors describe a case of epidural hematoma in association with dextran infusion in a patient who had undergone a peripheral vascular operation with epidural analgesia. Possible mechanisms for the anticoagulant effect of dextran and guidelines for the use of anticoagulant therapy in patients undergoing epidural anesthesia are discussed.

Preclinical studies of [(99m)Tc]DTPA-mannosyl-dextran

We report the preclinical testing of a synthetic receptor-binding macromolecule, [(99m)Tc]DTPA-mannosyl-dextran (36 kDa, 8 DTPA and 55 mannosyl units per dextran, K(D) = 0.12 nM), for sentinel node detection. Nonclinical safety studies included cardiac pharmacology safety studies, acute toxicology and pathology studies at 50 and 500 times the scaled human dose in both rats and rabbits after foot pad administration, and perivascular irritation studies in rabbits following intra-muscular administration at 100 and 1000 times the scaled human dose. Biodistribution studies in rabbits at 15 m, 1 h, and 3 h indicated that [(99m)Tc]DTPA-mannosyl-dextran cleared the hind foot pad with a biological half-life of 2.21 +/- 0.27 h. Other than mild hepatocyte hypertrophy in rabbits, no abnormalities in toxicology or pathology were found. Intravenous administration had no effect on survival, any clinical observations, electrocardiograms, or blood pressures. Intramuscular injection had no effect on survival, clinical observations, injection site observations, or injection site histopathology. The estimated absorbed radiation dose to the affected breast was 0.15 mGy/MBq and the effective dose was 1.06 x 10(-2) mSv/MBq. This preclinical study demonstrates that [(99m)Tc]DTPA-mannosyl-dextran has no toxicities and has an acceptable biodistribution and radiation dose.

Dextrans in microsurgery: A review

This articles reviews the use of dextrans in free tissue transfer. Current recommended regimes, indications, and complications are discussed. In conclusion, dextrans cannot be used as a substitute for good surgical technique, and should be utilized cautiously, especially in the elderly.

Efficacy of hypertonic saline dextran fluid resuscitation for patients with hypotension from penetrating trauma

BACKGROUND

The purpose of this study was to assess whether the administration of hypertonic saline dextran (HSD) was detrimental when administered to patients who were hypotensive because of penetrating injuries to the torso. The administration of HSD causes an immediate and sustained increase in blood pressure that could contribute to an increase in bleeding in the presence of uncontrolled hemorrhage. We prospectively designed a series of questions to be addressed by a meta-analysis of individual patient data using a computerized data file and case report forms from a multicenter study of HSD.

METHODS

The investigators were "blind" as to the treatment the patient received. Patients (n = 230) with penetrating injuries to the torso were studied as to survival until discharge. The patients were administered 250 mL of HSD or normal saline (standard of care [SOC]) as the initial fluid therapy.

RESULTS

Of the 120 patients treated with HSD, 82.5% survived compared with 75.5% for 110 SOC patients (p = 0.19). Sixty-eight percent (n = 157) of these patients required surgery. HSD treatment (n = 84) in this population improved survival, 84.5% compared with 67.1% with SOC (n = 73) (p = 0.01). HSD resulted in an increase in blood pressure and a reduction in hematocrit, with no differences noted in fluid requirements or indices of clotting.

CONCLUSION

For patients with penetrating injuries to the torso that result in hypotension, initial fluid resuscitation with HSD is beneficial in improving survival, especially if surgery is subsequently required.

Vaccine allergy and pseudo-allergy

Allergic and pseudo-allergic reactions to vaccines frequently involve the skin, and can be generalized systemic symptoms (urticaria/angioedema, serum sickness, flares of eczema) or localized at the sites of vaccination (persistent nodules, abcesses, granulomas). Diagnosis of Arthus-type reactions is based on clinical history and specific IgM/IgG anti-toxoid determination. For other local reactions, diagnostic value of non-immediate responses in skin tests varies with clinical symptoms and substances involved. Immediate responses in skin tests and specific IgE determination have good diagnostic and/or predictive value in anaphylaxis and immediate/accelerated urticaria/angioedema to toxoid-, pneumococcus-, and egg- and gelatin-containing vaccines. Diagnosis of reactions to dextran in BCG is based on specific IgM/IgG determination. Most non-immediate generalized reactions result from non-specific inflammation, except for gelatin-containing vaccines, but the diagnostic value of immuno-allergological tests with the vaccines and gelatin are controversial. Withholding booster injections is advised if specific IgM/IgG levels are high. If the levels are low, sequential injections of vaccines containing a single vaccinating agent are usually tolerated. However, injections of the vaccine should be performed using a " desensitization " procedure in patients reporting anaphylaxis and immediate/accelerated urticaria/angioedema.

[Severe adverse event following iv administration of 10 ml 6% Dextran60 (0.6 g) in a healthy volunteer]

We describe the case of a 24-year-old healthy volunteer who underwent a dextran-induced anaphylactic/anaphylactoid reaction (DIAR) type III after administration of 10 ml 6% Dextran60 (0.6 g) during a preliminary examination. There were no specific incidents in the medical history or any infusions of any colloids. In contrary to other DIAR case reports of anaphylactic reactions, in this case we observed a latency period after intravenous application of Dextran60 to the first clinical symptoms of anaphylactic shock of about 5 min. The initial decrease of systolic blood pressure to less than 90 mmHg and consecutive increase in heart rate to higher than 90 bpm returned to normal after therapy with head-down position, iv injection of 2 mg Clemastin, 100 mg hydrocortisone and infusion of 500 ml hydroxyethyl starch after approximately 8 min. During this period responsiveness was unsatisfactorily although the volunteer complained about warming of the skin, paresthesia and nausea. Immediate shock symptoms that normally belong to antigen-antibody reactions were not observed. It is therefore still unclear whether this case was caused by antibody reactions. Nevertheless, to provide DIAR it is still absolute necessary to give 20 ml Promit((R)) 15% in advance. It is not an acceptable alternative to infuse the first 100 ml of dextran as a bolus and it must remain a point of discussion as to whether the reactions described could have been due to a bolus administration of the first 100 ml Dextran. It is absolutely necessary to accurately monitor the first 10 min after an infusion even if only small volumes of dextran (i.e. 0.6 g) are infused. This is becoming more and more important due to the increasing use of "small volume resuscitation", solutions containing dextran (RescueFlow((R)), Biophausia AB, Uppsala, Schweden) or cryoconservation with dextran.

[Effects of plasma substitutes on hemostasis]

OBJECTIVE

Data synthesis on haemostasis effects of cristalloids and colloids and clinical implications for their use for plasma volume replacement.

DATA SOURCES

Data were searched in the Medline database from 1954 to 2000 using the following key-words: cristalloids, colloids, albumin, gelatin, dextran, hydroxyethyl starch, haemostasis, von Willebrand disease, haemodilution.

DATA EXTRACTION

Publications from 1954 to 1990 were selected depending on the quality of their methodology. Most of articles published after 1990 and all types including case report were accepted.

DATA SYNTHESIS

Cristalloids induces a moderate hypercoagulable state with 10 to 30% haemodilution. Hypocoagulation is observed above 50% haemodilution. Albumin does not impair hemostasis except with a 50% or more haemodilution where hypocoagulation is observed. Dextran dramatically impairs haemostasis and fibrinolysis. With increasing dose, a progressive decrease of all von Willebrand multimers, mostly the largest, is observed. Till 50% haemodilution, gelatin has a moderate impact on hemostasis, but platelet aggregation is moderately modified. However this moderate impairment of haemostasis may potentiate the haemostatic effect of other colloids when used in association with gelatin. More than 30% haemodilution with hydroxyethyl starch (HES) has a serious effect in vitro on platelet function and fibrinoformation. In most studies in human, less than 20 ml.kg-1 plasma volume replacement has no clinical impact, but in some evaluations postoperative bleeding is more important with HES, particularly HES 450, in comparison to other colloids. With HES 450 and HES 200 highly substituted (0.6 of degree of substitution) intravascular cumulation of large molecules leads to type I von Willebrand syndrome when doses overtake 80 ml.kg-1. Dextran and HES are prohibited in patients with impaired haemostasis due to congenital disease (haemophilia and von Willebrand disease) or acquired defect (thrombocytopenia). Caution is required in patients with renal failure or receiving antithrombotic or non-steroidal anti-inflammatory agents. Patients without a haemorrhagic diathesis must not received more than 1.5 g.kg-1.j-1 of dextran and restrictive conditions of use must be respected with HES.

CONCLUSION

Except isotonic cristalloids, all colloids induce haemostastic changes particularly for haemodilution over 30%. Effects are more pronounced with HES and dextran.

Dextran-induced pulmonary edema in patients with sudden deafness

OBJECTIVE

Pulmonary complication in cases of sudden deafness after dextran treatment is rarely reported. This study discusses the management of two cases and reviews the current literature.

PATIENTS

Two (1%) of 204 patients with sudden deafness patients had fever, cough, and dyspnea after intravenous dextran infusion. Pulmonary edema was diagnosed after chest radiographic examination.

RESULTS

After interruption of dextran, subsequent supportive treatment relieved chest discomfort and fever without any sequelae. The results of chest radiograph and laboratory studies, including hemogram, renal function, and arterial blood oxygen saturation, were normal.

CONCLUSIONS

Patients receiving dextran treatment should have their clinical symptoms, renal function, chest radiographs, hemogram, and coagulation profiles monitored. If fever, bleeding, cough, or dyspnea occurs during treatment, dextran must be immediately stopped. Subsequent treatment should focus on dextran clearance to prevent further cascade complications.