[Epithelial damage of corneal grafts after prolonged storage in dextran-containing organ culture medium - a prospective study]

BACKGROUND

High-molecular dextran added to organ culture medium is used for deswelling of corneal grafts before surgery. As we had the impression to have more often epithelial desquamation if storage time in dextran-containing medium was longer than 1 day, we investigated this problem in a pilot study.

METHODS

We examined prospectively the effect of the storage period on the graft epithelium one day after penetrating keratoplasty in 137 corneal grafts which were stored in dextran-containing storage medium (dextran T500 6 %). 88 corneal grafts were stored for 1 - 2 days (12 - 48 hours) and 49 corneal grafts were stored for 3 - 4 days (60 - 96 hours). Before deswelling, all 137 grafts had been stored 10 - 14 days in dextran-free organ culture medium. Postoperative epithelial defects observed 1 day after surgery were classified as margin and central erosions of the graft.

RESULTS

With a storage period in dextran-containing organ culture medium of 1 - 2 days statistically significantly less epithelial defects were observed in comparison to a longer storage period of 3 - 4 days (33 % vs. 57 %, p = 0,005). We found a statistically high significant correlation between storage time in dextran-containing organ culture medium and central erosions (p = 0,001), whereas margin erosions were observed after 1 - 2 days as well as after 3-4 days (p = 0,2).

CONCLUSION

Our data show that early postoperative epithelial stability of corneal grafts depends on the storage period in dextran-containing organ culture medium.

Safety of hypertonic hyperoncotic solutions--a survey from Austria

BACKGROUND

Hypertonic hyperoncotic solutions (HHS), composed of 7.2 to 7.5% sodium chloride and 6 to 10% dextran or hydroxyethyl starch, are able to restore the disturbed macro- and microcirculation in hypovolemic states within a short period of time. Even small amounts of HHS induce a relevant fluid shift from the extravasal into the intravasal space, and the use of HHS has thus been recommended in acute hypovolemia and hypovolemic shock (principle of "small-volume resuscitation"). Recently, attention has also focused on the treatment of elevated intracranial pressure using HHS. Austria is the only European country where market authorization of HHS was already obtained several years ago and where HHS have been widely used in clinical routine for a comparatively long time. This offers the unique possibility of evaluating, for the first time, the safety profile of HHS solutions. In this study, we analyzed the reported adverse drug reactions of HHS in a large number of applications.

METHODS

Marketing and pharmacovigilance data as well as other relevant information obtained in Austria during the years 1991 to 2000, were used for analysis of safety aspects of HHS applications in routine clinical practice.

RESULTS

From 1991 to 2000, four adverse drug reactions related to HHS were reported, none of which was fatal. Out of these, 3 have to be regarded as anaphylactoid/anaphylactic reactions to hydroxyethyl starch. In one case an extreme overdose was infused resulting in a hyperosmolar syndrome. In the same time period approximately 56,000 HHS units were used in Austria in about 18,500 to 37,000 patients. With these numbers, the frequency of adverse drug reactions related to the prescribed application of HHS can be calculated: approximately 5 adverse drug reactions per 100,000 HHS units used; approximately 8-16 adverse drug reactions per 100,000 HHS-treated patients.

CONCLUSION

Austrian experience with the use of a large number of HHS in clinical routine during nearly a decade indicates that the prescribed application of a combination of hydroxyethyl starch and hypertonic sodium chloride has a low potential for complications.

Acute renal failure during dextran-40 antithrombotic prophylaxis: report of two microsurgical cases

Dextran is often used to enhance the successful outcome of microvascular transplantations. So far, some 60 cases of dextran-induced acute renal failure have been reported. Among them, only one has been reported as an adverse reaction to antithrombotic prophylaxis during microvascular surgery. To stress that dextran prophylaxis can be a serious threat to microsurgical patients, the authors report on two more such patients and discuss how to prevent and treat this condition. Hypovolemic patients of older age are at risk, as are patients with cardiovascular diseases, renal artery stenosis, and preexisting renal insufficiency. Dextran should be discontinued promptly in patients with decreased urinary output or with high urine specific gravity. Dextran-induced acute renal failure may be severe and it may last several days. Plasmapheresis is the therapy of choice and, usually, diuresis and renal function resume shortly after such treatment.

Treatment of cirrhotic tense ascites with Dextran-40 versus albumin associated with large volume paracentesis: a randomized controlled trial

Intravenous albumin infusion prevents complications after large-volume paracentesis (LVP), particularly paracentesis-induced circulatory dysfunction (PCD), and improves patient survival. However, albumin is expensive. We compared a low-molecular weight dextran (Dextran-40) with albumin in treating LVP in cirrhotic patients with tense ascites. Sixty-nine cirrhotic patients were included and 96 LVPs were performed. Any repeat punctures on the same patient were at least three months apart. Patients were randomized to receive either i.v. Dextran-40 infusion (Group I, n = 48) or i.v. albumin infusion after LVP (Group II, n = 48). Clinical, biochemical, and hormonal evaluations were done before and after LVP. Patients were followed up for the detection of any recurrence of ascites or complications. The two groups were similar in age, sex, and etiology of cirrhosis, and in the volumes of ascites recovered. Significant decreases in mean arterial pressure were observed in both groups 24 and 48 h after LVP. Urine volumes increased significantly at 24 h in both groups (p < 0.05), but remained high only in Group I. Plasma renin activity and aldosterone concentrations increased in both groups 48 h after LVP, but they were more marked in Group I. Complications developed in 17 % of patients treated with Dextran-40 and in 23 % treated with albumin (p > 0.05). Ascites recurrence rates and survival were similar in the two groups. In conclusion, Dextran-40 was thus not as efficacious as albumin for preventing PCD.

Complication of oliguric acute renal failure in patients treated with low-molecular weight dextran

Acute renal failure (ARF) is a well-documented but infrequent complication in patients treated with low-molecular weight dextran (LMWD). We herein report 3 cases of oliguric ARF following the administration of dextran-40. One case developed ARF totally after 1.200 g of LMWD administration. In contrast, two cases having increased serum creatinine developed oliguria despite the acceptable therapeutic doses (totally 450 and 650 g). Contrast media was also co-administered in these patients. Plasma exchange (PE), double filtration plasmapheresis (DFPP), or continuous hemodiafiltration (CHDF) but not hemodialysis (HD) reduced circulating dextran concentrations by 35-44% during a single session. All patients completely recovered from ARF by 14-32 days after the treatment. Our cases suggested that radiocontrast could predispose to the development of LMWD-induced ARF especially in patients having pre-existing renal dysfunction. In addition, PE, DFPP and CHDF afforded a beneficial effect for removing accumulated LMWD from the circulation.

Acute renal failure in a healthy young adult after dextran 40 infusion for external-ear reattachment surgery

Dextran 40 is used to improve the microcirculation after certain surgical procedures. We report a rare case of acute anuric renal failure in a healthy young adult after administration of dextran 40 to improve the microcirculation following ear-reattachment surgery. The renal failure was subsequently reversed by plasmapheresis and intensive care support. Although rare in the young and fit, the risk of developing acute anuric renal failure exists with administration of dextran 40 and appropriate monitoring is essential.

[Antiphlogisitc-rheologic infusion therapy of acute idiopathic facial paralysis. Experiences and results of 344 cases]

Antiphlogistic-rheologic infusion therapy is a widespread and well-established treatment modality for acute idiopathic facial paralysis (AIFP) in many German centers of otorhinolaryngology. However, there is still a lack of convincing data concerning this regimen's functional results and side effects. The medical records of 344 patients who were treated for AIFP between 1987 and 1997 were analyzed retrospectively. In 239 cases there was reliable information on functional outcome. Therapy consisted uniformly of intravenous infusion with prednisolone (250 mg initially, then tapering over 18 days) and simultaneous administration of dextran and pentoxifylline. From 239 patients with non-recurrent palsy having received treatment within 12 days after onset, 92.1% recovered completely without sequelae. In case of incomplete palsy (House-Brackmann grade II-V), normal facial function was restored in 97.7% of cases. Results were significantly better in the group in which therapy had been started within 3 days after onset of palsy. Adverse effects occurred rarely and were transient and mild in most cases. High-dose prednisolone in combination with low-molecular dextran and pentoxifylline for AIFP is a safe treatment modality leading to recovery rates superior to the most optimistic observations of the natural course of Bell's palsy. In the absence of a definitive controlled trial, the present study, although retrospective, is considered valid to show the effectiveness of our protocol. In the light of our data and of other publications, early treatment with corticosteroids in sufficient dosage seems appropriate, while therapeutic nihilism in AIFP does not seem justified.

[The Stennert antiphlogistic-rheologic infusion schema in treatment of cochleovestibular disorders]

The pathogenetic mechanisms of acute cochleo-vestibular lesions are still unknown, but viral infections and vascular phenomena with impairment of microvascular perfusion are thought to play a major role. Between 1 July, 1986 and 28 February 1998, 1501 patients were treated with an infusion protocol using cortisone, dextrane 40 and pentoxifylline. Group 1 contained 1001 patients with sudden hearing loss, group 2a 107 patients with isolated tinnitus and group 2b 393 patients with labyrinthine disorders (among which were 81 patients with cochleovestibular dysfunction). The records were evaluated retrospectively. In group 1 complete hearing recovery occurred in 44.8%, partially in 40.4%, no change in 12.1% and worsened in 2.6%. In group 2a with isolated tinnitus 17.9% had a complete recovery, 43.9% partial recovery, 35.5% no change and 2.8% worsened symptoms. In group 2b vertigo disappeared in 56.8%, had partial recovery in 21.0% and did not change in 7.4%. In the 1501 patients treated, no significant side-effects were found to the medical interventions used. From these results we conclude that the infusion protocol is safe and effective in the treatment of cochleo-vestibular disorders.

Endoscopic treatment of children with vesico-ureteric reflux

Endoscopic subureteric injection of tissue-augmenting substances has become an alternative to long-term antibiotic prophylaxis and open surgery in the treatment of children with vesico-ureteric reflux. Successful elimination of reflux in about 80% of patients after a single injection (and in 90% after a repeat) has been achieved using the foreign-body non-degradable substances Teflon and silicone. Few patients have required open surgery and recurrence of reflux after initial successful treatment has occurred in only 5-10%. Concern has arisen, however, about possible distant migration and granuloma formation after injection of particulate plastic materials. Cross-linked bovine collagen is a biodegradable alternative substance, but with a lower response rate of 60% after the first treatment and a recurrence rate of 10-20%. Dextranomer in sodium hyaluronan is a new biological substance with microparticles with a response rate of 69% after the first injection. Biological substances have caused few complications. Present literature on injection treatment unfortunately focuses on elimination of reflux, with little attention to subsequent frequency of pyelonephritis or to the long-term development of the kidneys. Furthermore, there are no controlled, randomized studies with subureteric injection as one of the treatment alternatives. Thus, although having the advantage of being a minimally invasive procedure that can be performed on an outpatient basis, this technique needs to be tested in a large prospective study with the long-term renal outcome as the main end-point.

The adult respiratory distress syndrome after dextran infusion as an antithrombotic agent in free TRAM flap breast reconstruction

Adult respiratory distress syndrome occurred in a patient who had received dextran as a routine antithrombotic agent during and after free TRAM breast reconstruction. Although most patients who receive dextran have no adverse reaction, particularly after hapten inhibition by dextran 1 infusion, the serious nature of this complication in an elective operation calls into question the continuing routine use of dextran in microsurgery.

Pulmonary inflammation without bronchial hyperresponsiveness in vivo or in vitro after sephadex instillation in pigs

1. In rodent models, Sephadex produces pulmonary inflammation that may be associated with bronchial hyperresponsiveness. In the present study we examined whether Sephadex-induced inflammation altered airway narrowing in pigs. 2. Twenty millilitres of 10 mg/mL Sephadex suspension was instilled twice intratracheally into anaesthetized pigs (days 1 and 7 of a 9 day study). In vivo bronchial responsiveness was assessed from the effect of acetylcholine (ACh) aerosol on airways resistance and dynamic compliance before Sephadex instillation and on days 3, 5 and 9. Lung histology and in vitro bronchial responsiveness was assessed on day 9. In vitro responsiveness was assessed by measuring the reduction in flow through perfused 2 mm i.d. bronchial segments in response to ACh applied luminally and adventitially. 3. Sephadex produced a focal peribronchial granulomatous reaction characterized by the presence of macrophages, eosinophils, neutrophils and giant cells. Changes in airway resistance and lung compliance in response to ACh did not change over the study period. The response of perfused bronchial segments to luminally or adventitially applied ACh was also unaltered. 4. Sephadex-induced pulmonary inflammation does not alter airway narrowing in vitro nor bronchial hyperresponsiveness in vivo in the pig.

Effects of ketorolac and dextran-70 alone and in combination on haemostasis

BACKGROUND

Dextran may be used in surgical patients for thromboprophylaxis or volume expansion along with ketorolac, a nonsteroidal anti-inflammatory drug, for analgesia. As these two agents can influence the haemostatic system at different sites, it is important to demonstrate that there is no adverse haemostatic interaction between them.

METHODS

The haemostatic interaction between intravenous dextran-70 and intramuscular ketorolac was assessed in a double-blind, randomised, crossover study of healthy male volunteers each given all four combinations of ketorolac/placebo intramuscularly and dextran/placebo intravenously. The effect of ketorolac and dextran on haemostasis was assessed by the following techniques: skin bleeding time, in vitro platelet aggregation function, whole blood thromboxane generation, von Willebrand factor antigen, factor VIII coagulant activity and tissue plasminogen activator. The results were analysed for the effects of ketorolac and dextran and for any evidence of an interaction.

RESULTS

Ketorolac inhibited platelet function and thromboxane generation. Dextran reduced factor VIII coagulant activity. Neither agent had a significant effect on bleeding time, von Willebrand factor or tissue plasminogen activator. There was only evidence of a small but statistically significant interaction between ketorolac and dextran on thromboxane generation. There was no evidence of any other interaction of ketorolac with dextran.

CONCLUSION

This interaction on thromboxane generation is unlikely to be of clinical significance as substantial inhibition of thromboxane generation occurs with ketorolac alone.

Inhibition of pulmonary eosinophilia does not necessarily prevent the airway hyperresponsiveness induced by Sephadex beads

BACKGROUND

The Lewis rat among highly inbred strains exhibits significant airway hyperresponsiveness (AHR) following intravenous administration of Sephadex G-200 (Sephadex). The aim of this study was to investigate the association of Sephadex-induced AHR with changes in airway inflammation in Lewis rats.

METHODS

A suspension (0.5 mg/ml/rat) of Sephadex was intravenously administered to male Lewis rats on days 0, 2 and 5. Measurement of airway responsiveness to serotonin, bronchoalveolar lavage (BAL) and histological study were performed on day 2-11.

RESULTS

Significant AHR induced by Sephadex was recognized on day2 (p < 0.05), and AHR reached a maximum on day 7 (p < 0.001). In the BAL study, eosinophils increased on day2 (p < 0.01) with a peak on day 5 (p < 0.05). In the histological study, we found Sephadex beads trapped in small arteries of the lung and granulomatous arteritis on day 2 or later. Pulmonary granulomas, horseshoe-shaped multinuclear giant cells, eosinophils and goblet cell hyperplasia were observed on day 2, and the degree became intense on day 5-7. GCC-AP0341 (10 mg/kg, i.p. x 3) inhibited the recruitment of eosinophils in BAL fluid and in lung tissue, but it did not inhibit AHR. The compound also inhibited pulmonary granulomas and goblet cell hyperplasia.

CONCLUSION

The mechanism of Sephadex-induced AHR may not be directly associated with inflammatory changes such as recruitment of eosinophils, pulmonary granulomas and hyperplasia of goblet cells in rats.

[Excessive tissue storage of colloids in the reticuloendothelial system]

In addition to renal elimination and gastrointestinal metabolism (amylase; splenic and hepatic dextranase) colloid plasma solutions like dextran and hydroxyethyl starch deposit in tissues, especially in the reticuloendothelial system (RES). This tissue storage is limited in time (weeks to months), is influenced by the employed solution and other factors (lysosomes) and has usually no clinical importance (no RES blockade). We report here a case study of a patient with sepsis (lung, liver and kidney failure) who had an overload of the RES with colloids while being treated with dextran (molecular weight 40,000 and 70,000 daltons) and hydroxyethyl starch (mw 450,000 daltons, molar substitution 0,7) for 5 weeks. Autopsy showed parenchymal and reticuloendothelial cells of liver, lung, kidney and spleen with a large amount of colloid mass inclusions and altered organ morphology. This storage may have impaired ventilation, transport of bile acids and renal function. A possible role of tissue storage of colloids in organ failure is discussed.

Improved dextran preparation of human leucocytes for chemiluminescence analysis of the oxidative burst of polymorphonuclear cells

An improved method for the preparation of leucocyte-rich plasma from human blood samples for chemiluminescence (CL) analysis is described. Heparinized blood is layered over 4% dextran in a ratio of 1:1 (v/v). The leucocyte-rich plasma is obtained after a 1 h sedimentation of the erythrocytes. When compared with the plasma obtained by the usual method of mixing blood with dextran, the residual red cell count was reduced. On the other hand, the index of phagocytosis (peak values of activated phagocytosis/spontaneous phagocytosis) was increased. This is caused by increased spontaneous CL activity after mixing blood with dextran, which can activate leucocytes. Such activation was observed both in plasma samples and in whole blood samples when measured immediately after dextran addition or after 1 h incubation with dextran.

Transvaginal ultrasonographic assessment of Hyskon or lactated Ringer's solution instillation after laparoscopy: randomized, controlled study

We sought to evaluate two common fluids placed in the pelvis after pelvic surgery for their ability to remain in the pelvis for a time thought adequate for prevention of adhesions. Thirteen patients undergoing operative laparoscopy were randomized to receive 250 ml 32% dextran 70 (Hyskon), 250 ml lactated Ringer's solution, or no fluid (control) at the end of surgery. Serial transvaginal ultrasonograms were obtained at 1 hr, 3 hr, 6 hr, 24 hr, 96 hr (4 days), and 168 hr (7 days) after surgery. Patients were asked about side effects of fluid instillation. The volume of lactated Ringer's solution declined rapidly after instillation, with no significant difference from control at 24 hr (12 ml versus 7 ml). The volume of Hyskon did not decline rapidly by 24 hr and remained higher than the volume in controls or those receiving lactated Ringer's solution (188 ml, P = 0.003). Although the volume of Hyskon remained higher than that of lactated Ringer's solution or fluid volume in control patients by days 4 and 7, this difference did not reach statistical significance (45 ml versus 7 ml and 14 ml respectively, P = 0.39, on day 4). Patients in all groups noted abdominal pain. One patient who received Hyskon developed severe vulvar edema and another developed dyspnea. We conclude that the volume of Hyskon in the peritoneal cavity after laparoscopy does not decline as rapidly as does that of lactated Ringer's solution; however, significant side effects may limit its usefulness. Transvaginal ultrasonography is useful in monitoring fluids placed in the pelvis for prevention of adhesions.