A study of three untoward reactions to dextran

The role of hypertonic saline dextran in trauma resuscitation

Modern trauma management has recognized the importance of using conservative fluid resuscitation regimes in order to prevent complications from fluid overload arising. Hypertonic/hyperoncotic fluids appear to provide an ideal means of facilitating this, requiring only small volumes to rapidly elevate blood pressure. Hypertonic saline dextran (HSD) was introduced in 1985 but its take up has been slow, a large part of this has been due to the lack of human trials and concerns about complications.

The current evidence has been reviewed and it is clear that HSD is an efficient means of correcting hypotension, doing so mainly by the mobilizing endogenous water. It is becoming apparent that early administration has the potential to modulate the inflammatory cascade in patients at risk of developing adult respiratory distress syndrome (ARDS) and multiorgan failure. This is reflected in the handful of human trials that show a trend towards increased survival (particularly for head injuries) and a possible reduction in ARDS. The side effect profile appears to be good, even in the presence of dehydration or penetrating trauma.

Published human trials have methodological problems and lack of power of study this has led to a reliance on animal studies. Clearly there is great potential, but before large-scale prehospital usage can be justified further well-conducted randomized human trials are needed.

Anaphylactoid reactions to Dextran 40 and 70: Reports to the United States Food and Drug Administration, 1969 to 2004

BACKGROUND

Clinical dextrans, such as Dextran 40 and Dextran 70, are associated with anaphylactoid reactions caused by dextran-reactive immunoglobulin G antibodies. When infused immediately before clinical dextrans, dextran 1 significantly reduces the incidence of severe anaphylactoid reactions. The objective of the study was to describe the frequency and characteristics of reports submitted to the United States Food and Drug Administration (FDA) for anaphylaxis or anaphylactoid events after clinical dextran administration.

METHODS

We searched the FDA's Adverse Event Reporting System for reports associated with a clinical dextran and describing anaphylaxis/anaphylactoid reactions. Our case definition for a probable anaphylaxis/anaphylactoid event required signs or symptoms from at least two body systems, with at least one sign or symptom being hypotension, vasodilation, or respiratory difficulty, and onset within 60 minutes. Other reports were considered possible cases if the reporter specifically described the reaction as anaphylaxis or an anaphylactoid reaction. Premier RxMarket Advisor provided estimates of total US hospitalizations with clinical dextran or dextran 1 administration from 2000 to 2004, based on discharge billing data from a sample of US hospitals. The IMS National Sales Perspective provided estimates of total doses of dextrans sold in the United States from 1999 to 2004, based on volumes of dextrans sold in a sample of retail and nonretail outlets.

RESULTS

The FDA received 366 clinical dextran adverse event reports from 1969 to 2004, of which 90 (24.6%) were anaphylaxis/anaphylactoid events. The ratio of hospitalizations where clinical dextran was administered to hospitalizations where dextran 1 was administered was 28.4:1. The expected ratio would be 1:1 if all clinical dextran patients had received dextran 1 pretreatment. The ratio of clinical dextran doses sold to dextran 1 doses sold in the United States was 38.6:1.

CONCLUSIONS

A high proportion of adverse event reports for clinical dextrans described anaphylaxis or anaphylactoid reactions. Hospital discharge and product sales data suggest that dextran 1 has not been used consistently before clinical dextran administration in recent years. To reduce the risk of anaphylactoid reactions, physicians should consider routine administration of dextran 1 before the infusion of a clinical dextran.

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.

Anaesthetic implications of 32% Dextran-70 (Hyskon) during hysteroscopy: hysteroscopy syndrome

This review describes the properties and side effects of Hyskon and the implications for the patient and anaesthetist during hysteroscopy. The amount of Hyskon absorbed is dependent on the injection pressure, the extent of tissue trauma, the seal of the hysteroscope around the cervix, and the duration of infusion. The mechanism of pulmonary oedema after absorbtion of Hyskon is fluid overload, and not injury to pulmonary capillary endothelium. The haematological effects are primarily due to haemodilution. However, case reports suggest that Dextran 70 may cause a syndrome resembling disseminated intravascular coagulation. The allergic response to Hyskon consists of both an anaphylactic and an anaphylactoid component. It is recommended that hysteroscopy with Hyskon be limited to 45 min, and that all possible measures be taken to minimize tissue trauma and bleeding. The volume of Hyskon should be limited to less than 500 ml, since pulmonary oedema and coagulopathy have been described with even lesser amounts. The cumulative volume of Hyskon should be monitored frequently and the patient should be closely monitored for signs of impending pulmonary oedema.

Immunoglobulin class and subclass distribution of dextran-reactive antibodies in human reactors and non reactors to clinical dextran

The red cell-linked antigen-antiglobulin reaction (RCLAAR) with stearoyldextran-coated erythrocytes was used to characterize the immunoglobulin (Ig) classes and IgG subclasses of dextran reactive antibodies (DRA) in 27 dextran reactors (DR) and 96 on reactors (DNR). High titres of dextran reactive IgG were regularly found in sera of patients with severe dextran-induced anaphylactoid/anaphylactic reactions (DIAR) prior to the infusion. In four lethal cases IgG antibodies were found to be in the highest titre range of 16,384 to 32,768. In addition, high IgA and IgM titres were also in severe DIAR. DNR had much lower titres of dextran reactive antibodies of IgG, IgM and IgA classes and IgD antibody was absent in both groups. Dextran reactive IgE antibodies were not demonstrable in DR. Dextran reactive IgG2, IgG3, IgG4 and IgG1 (indirect measurement) were demonstrated in both DR and FNR. Dextran infusion caused variable neutralization in all Ig classes and IgG subclasses, but the contribution of IgG2 was considered most important because of its high titres and most pronounced neutralization in severe DIAR. It is concluded that DRA mainly of the IgG class, play a critical pathogenic role in the induction of severe DIAR, which accordingly is classified as immune complex (Type III) anaphylaxis. The method of RCLAAR allows to delineate a risk group of about 2% of potential reactors.

Anaphylactoid reaction to 50% solution of dextrose

Two patients with extrinsic asthma and coexistent insulin-dependent diabetes mellitus sustained an anaphylactoid reaction after the intravenous administration of 50% solution of dextrose. Investigations suggested that the dextrose, rather than any additives, was responsible for the reaction. The effect of varying concentrations of dextrose on the histamine content of the blood of normal, allergic, non-diabetic and diabetic, and non-allergic patients was studied. Preliminary results suggest that the higher concentrations of dextrose induce increased histamine release from blood cells, and that this phenomenon is more marked in diabetic, and particularly diabetic-allergic, individuals. We suggest that the treatment of hypoglycaemia with 50% solution of dextrose is associated with a significant risk factor in those diabetic individuals who are either allergic or are receiving beta-adrenoreceptor blocking drugs.

Hysteroscopy in 100 patients

Seventy-five infertile patients and twenty-five in whom displacement of an intrauterine device (IUD) had occurred were examined under general anesthesia. The Storz 4-mm hysteroscope was utilized. In all cases Hyskon, high-molecular weight dextran, was used as the distention medium. Concurrent laparoscopy was performed in 80 patients. The hysteroscopic findings were compared with preoperative salpingograms or pelvic x-radiographs. In the infertility group the technique proved to be of special value in locating intrauterine adhesions which had not been detected radiologically. In the "lost IUD" group, hysteroscopy proved to be superior to radiography in determining whether or not a device was located within the uterine cavity, and greatly facilitated removal. Failure to carry out the procedure occurred in four patients. One suffered a serious complication: anaphylaxis to the dextran. It was concluded that hysteroscopy is a simple procedure carrying little risk. It is superior to hysterosalpingography in detecting intrauterine disease which may be a cause of infertility. It is greatly superior to radiology for the detection of lost IUDs.